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2. |
- Ahmad, Irma, et al.
(author)
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High prevalence of persistent symptoms and reduced health-related quality of life 6 months after COVID-19
- 2023
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In: Frontiers In Public Health. - : Frontiers Media S.A.. - 2296-2565. ; 11
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Journal article (peer-reviewed)abstract
- BACKGROUND: The long-term sequelae after COVID-19 constitute a challenge to public health and increased knowledge is needed. We investigated the prevalence of self-reported persistent symptoms and reduced health-related quality of life (HRQoL) in relation to functional exercise capacity, 6 months after infection, and explored risk factors for COVID-19 sequalae.METHODS: This was a prospective, multicenter, cohort study including 434 patients. At 6 months, physical exercise capacity was assessed by a 1-minute sit-to-stand test (1MSTST) and persistent symptoms were reported and HRQoL was evaluated through the EuroQol 5-level 5-dimension (EQ-5D-5L) questionnaire. Patients with both persistent symptoms and reduced HRQoL were classified into a new definition of post-acute COVID syndrome, PACS+. Risk factors for developing persistent symptoms, reduced HRQoL and PACS+ were identified by multivariable Poisson regression.RESULTS: Persistent symptoms were experienced by 79% of hospitalized, and 59% of non-hospitalized patients at 6 months. Hospitalized patients had a higher prevalence of self-assessed reduced overall health (28 vs. 12%) and PACS+ (31 vs. 11%). PACS+ was associated with reduced exercise capacity but not with abnormal pulse/desaturation during 1MSTST. Hospitalization was the most important independent risk factor for developing persistent symptoms, reduced overall health and PACS+.CONCLUSION: Persistent symptoms and reduced HRQoL are common among COVID-19 survivors, but abnormal pulse and peripheral saturation during exercise could not distinguish patients with PACS+. Patients with severe infection requiring hospitalization were more likely to develop PACS+, hence these patients should be prioritized for clinical follow-up after COVID-19.
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3. |
- Anrup, Roland, et al.
(author)
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Centrala universitetsvärden hotas av bolagiseringsidén
- 2013
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In: Dagens nyheter. - 1101-2447.
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Journal article (pop. science, debate, etc.)abstract
- Högskolestiftelser. Förslaget att driva svenska universitet i stiftelseform öppnar för bolagisering. Men det är ingen riktig utredning, utan en politisk pamflett utan eftertanke. Privatisering av universitet hotar både oberoendet, forskningskvaliteten och samhällsnyttan, skriver 36 forskare vid svenska högskolor och universitet.
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4. |
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5. |
- Björnsson, Lars-Henrik, et al.
(author)
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Laddinfrastruktur och frekvensreglering : en fallstudie
- 2023
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Reports (other academic/artistic)abstract
- För att elnätet ska fungera måste frekvensen hållas inom snäva gränser och därför handlar Svenska Kraftnät upp olika typer av stödtjänster för frekvensreglering. De senaste åren har kostnaderna för dessa tjänster ökat kraftigt, bland annat till följd av en allt högre andel intermittent elproduktion. Behoven är prognostiserade att öka ytterligare under de kommande åren. Detta har skapat ett ökat intresse för batterier och deras möjligheter att stödja elnätet. Men batterier och tillhörande kraftelektronik är kostsamt. Samtidigt finns en stor och alltjämt växande batterikapacitet i landets elbilar och med hjälp av dubbelriktad laddning, så kallad vehicle-to-grid öppnas nya möjligheter att komma åt denna potential för att på ett mer resurseffektivt sätt balansera elnätet. Projektets övergripande mål har varit att utreda hur standardisering kan användas för att påskynda och öka användandet av elbilar som resurs för flexibilitetstjänster till elnätet. Bland annat har en fallstudie genomförts av Axess Logistics anläggning i Malmö hamn och möjligheterna för att deras långtidsparkerade elbilar ska kunna leverera frekvensreglering till elnätet har studerats. Resultaten visar på att studerade standarder i stort inte utgör ett direkt hinder för användandet av elbilar för frekvensreglering men att förändringar av exempelvis ISO15118 skulle kunna öka möjligheterna att använda elbilar för att leverera frekvensreglering. Till exempel genom införande av krav på mätnoggrannhet på aktiv effekt, förkortning av tillåtna svarstider, krav på lokal frekvensmätning med god noggrannhet. För långtidsparkerade bilar vore det framförallt värdefullt att arbeta fram, och i standard beskriva, en funktion där elbilens BMS kan uppmanas av EVSE att hålla batteriet i ett tillstånd där det kan användas för att snabbt svara på en begäran om i-/urladdning. Detta så att elbilen kan vara förberedd för frekvensreglering även om den för stunden inte aktivt laddar eller matar effekt till elnätet. Detta en åtgärd som skulle kunna ha stor positiv påverkan på möjligheterna för långtidsparkerade elbilar att leverera frekvensreglering. Exemplifierande användarcykler för långtidsparkerade bilar har studerats för FCR-N och FCR-D. Resultaten visar att den förväntade cyklingen skiljer stort mellan dessa olika frekvensregleringstjänster och antyder att valet av frekvensregleringstjänst behöver studeras utifrån både förväntad ekonomi och eventuellt batterislitage. Överslagsräkningar på eventuella intäkter från deltagande i frekvensreglering har genomförts och de preliminära resultaten visar att investering av dyrare laddinfrastruktur som klarar Vehicle-to-Grid skulle kunna återbetalas inom ett år med 2022 års nivåer av ersättning för frekvensreglering. I en framtid där nya elbilar antas ha stöd för Vehicle-to-Grid har potentialen för att använda långtidsparkerade elbilar på logistikanläggningar till frekvensreglering preliminärt bedömts ligga mellan 110 och 165 MW för svenska förhållanden. Detta motsvarar ca 5-8% av den nordiska FCR-marknaden. På sikt kan också långtidsparkerade bilar hos återförsäljare, flygplatser med mera att utgöra en betydande potential.
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6. |
- Cabrera, Carin C., et al.
(author)
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Increased iron absorption in patients with chronic heart failure and iron deficiency
- 2020
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In: Journal of Cardiac Failure. - : Elsevier BV. - 1071-9164 .- 1532-8414. ; 26:5, s. 440-443
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Journal article (peer-reviewed)abstract
- Background: Iron deficiency (ID) is common in patients with chronic heart failure (CHF), but the underlying causes are not fully understood. We investigated whether ID is associated with decreased iron absorption in patients with CHF.Methods and Results: We performed an oral iron-absorption test in 30 patients and 12 controls. The patients had CHF with reduced (n = 15) or preserved (n = 15) ejection fraction and ID, defined as s- ferritin < 100 mu g/L, or s-ferritin 100-299 mu g/L and transferrin saturation < 20%. The controls had no HF or ID and were of similar age and gender. Blood samples were taken before and 2 hours after ingestion of 100 mg ferroglycin sulphate. The primary endpoint was the delta plasma iron at 2 hours. The delta plasma iron was higher in the group with HF than in the control group (median increase 83.8 [61.5;128.5] mu g/dL in HF vs 47.5 [ 30.7;61.5] mu g/dL in controls, P = 0.001), indicating increased iron absorption. There was no significant difference between the groups with preserved or reduced ejection fraction (P = 0.46).Conclusion: We found increased iron absorption in patients with CHF and ID compared to controls without ID and HF, indicating that reduced iron absorption is not a primary cause of the high prevalence of ID in patients with CHF.
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7. |
- Ding Yuan, Chen, 1991, et al.
(author)
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Impact of in situ NH3 pre-treatment of LPCVD SiN passivation on GaN HEMT performance
- 2022
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In: Semiconductor Science and Technology. - : IOP Publishing. - 1361-6641 .- 0268-1242. ; 37:3
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Journal article (peer-reviewed)abstract
- The impact on the performance of GaN high electron mobility transistors (HEMTs) of in situ ammonia (NH3) pre-treatment prior to the deposition of silicon nitride (SiN) passivation with low-pressure chemical vapor deposition (LPCVD ) is investigated. Three different NH3 pre-treatment durations (0, 3, and 10 min) were compared in terms of interface properties and device performance. A reduction of oxygen (O) at the interface between SiN and epi-structure is detected by scanning transmission electron microscopy (STEM )-electron energy loss spectroscopy (EELS) measurements in the sample subjected to 10 min of pre-treatment. The samples subjected to NH3 pre-treatment show a reduced surface-related current dispersion of 9% (compared to 16% for the untreated sample), which is attributed to the reduction of O at the SiN/epi interface. Furthermore, NH3 pre-treatment for 10 min significantly improves the current dispersion uniformity from 14.5% to 1.9%. The reduced trapping effects result in a high output power of 3.4 W mm(-1) at 3 GHz (compared to 2.6 W mm(-1) for the untreated sample). These results demonstrate that the in situ NH3 pre-treatment before LPCVD of SiN passivation is critical and can effectively improves the large-signal microwave performance of GaN HEMTs.
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8. |
- Frisk, Christoffer, et al.
(author)
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Cardiac biopsies reveal differences in transcriptomics between left and right ventricle in patients with or without diagnostic signs of heart failure
- 2024
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In: Scientific Reports. - : Springer Nature. - 2045-2322. ; 14:1
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Journal article (peer-reviewed)abstract
- New or mild heart failure (HF) is mainly caused by left ventricular dysfunction. We hypothesised that gene expression differ between the left (LV) and right ventricle (RV) and secondly by type of LV dysfunction. We compared gene expression through myocardial biopsies from LV and RV of patients undergoing elective coronary bypass surgery (CABG). Patients were categorised based on LV ejection fraction (EF), diastolic function and NT-proBNP into pEF (preserved; LVEF ≥ 45%), rEF (reduced; LVEF < 45%) or normal LV function. Principal component analysis of gene expression displayed two clusters corresponding to LV and RV. Up-regulated genes in LV included natriuretic peptides NPPA and NPPB, transcription factors/coactivators STAT4 and VGLL2, ion channel related HCN2 and LRRC38 associated with cardiac muscle contraction, cytoskeleton, and cellular component movement. Patients with pEF phenotype versus normal differed in gene expression predominantly in LV, supporting that diastolic dysfunction and structural changes reflect early LV disease in pEF. DKK2 was overexpressed in LV of HFpEF phenotype, potentially leading to lower expression levels of β-catenin, α-SMA (smooth muscle actin), and enhanced apoptosis, and could be a possible factor in the development of HFpEF. CXCL14 was down-regulated in both pEF and rEF, and may play a role to promote development of HF.
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9. |
- Fureby, C., et al.
(author)
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Incompressible wall-bounded flows
- 2007
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Book (other academic/artistic)abstract
- Almost all flows of practical interest are turbulent, and thus the simulation of turbulent flow and its diversity of flow characteristics remains one of the most challenging areas in the field of classical physics. In many situations the fluid can be considered incompressible; that is, its density is virtually constant in the frame of reference, moving locally with the fluid, but density gradients may be passively convected with the flow. Examples of such flows of engineering importance are as follows: external flows, such as those around cars, ships, buildings, chimneys, masts, and suspension bridges; and internal flows, such as those in intake manifolds, cooling and ventilation systems, combustion engines, and applications from the areas of biomedicine, the process industry, the food industry, and so on. In contrast to free flows (ideally considered as homogeneous and isotropic), wall-bounded flows are characterized by much less universal properties than free flows and are thus even more challenging to study. The main reason for this is that, as the Reynolds number increases, and the thickness of the viscous sublayer decreases, the number of grid points required to resolve the near-wall flow increases. The two basic ways of computing turbulent flows have traditionally been direct numerical simulation (DNS) and Reynolds-averaged NavierâStokes (RANS) modeling. In the former the time-dependent NavierâStokes equations (NSE) are solved numerically, essentially without approximations. In the latter, only time scales longer than those of the turbulent motion are computed, and the effect of the turbulent velocity fluctuations is modeled with a turbulence model.
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10. |
- Hage, Camilla, et al.
(author)
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Metabolomic Profile in HFpEF vs HFrEF Patients
- 2020
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In: Journal of Cardiac Failure. - : Elsevier BV. - 1071-9164 .- 1532-8414. ; 26:12, s. 1050-1059
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Journal article (peer-reviewed)abstract
- Background: Heart failure with preserved ejection fraction (HFpEF) and HF with reduced ejection fraction (HFrEF) are associated with metabolic derangements, which may have different pathophysiological implications.Methods and Results: In new-onset HFpEF (EF of >= 50%, n = 46) and HFrEF (EF of <40%, n = 75) patients, 109 endogenous plasma metabolites including amino acids, phospholipids and acylcarnitines were assessed using targeted metabolomics. Differentially altered metabolites and associations with clinical characteristics were explored. Patients with HFpEF were older, more often female with hypertension, atrial fibrillation, and diabetes compared with patients with HFrEF. Patients with HFpEF displayed higher levels of hydroxyproline and symmetric dimethyl arginine, alanine, cystine, and kynurenine reflecting fibrosis, inflammation and oxidative stress. Serine, cGMP, cAMP, L-carnitine, lysophophatidylcholine (18:2), lactate, and arginine were lower compared with patients with HFrEF. In patients with HFpEF with diabetes, kynurenine was higher (P = .014) and arginine lower (P = .014) vs patients with no diabetes, but did not differ with diabetes status in HFrEF. Decreasing kynurenine was associated with higher eGFR only in HFpEF (P-interaction = .020).Conclusions: Patients with new-onset HFpEF compared with patients with new-onset HFrEF display a different metabolic profile associated with comorbidities, such as diabetes and kidney dysfunction. HFpEF is associated with indices of increased inflammation and oxidative stress, impaired lipid metabolism, increased collagen synthesis, and downregulated nitric oxide signaling. Together, these findings suggest a more predominant systemic microvascular endothelial dysfunction and inflammation linked to increased fibrosis in HFpEF compared with HFrEF.
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11. |
- Linde, Cecilia, et al.
(author)
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Baseline characteristics of 547 new onset heart failure patients in the PREFERS heart failure study
- 2022
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In: ESC Heart Failure. - : John Wiley & Sons. - 2055-5822. ; 9:4, s. 2125-2138
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Journal article (peer-reviewed)abstract
- Aim We present the baseline characteristics of the PREFERS Stockholm epidemiological study on the natural history and course of new onset heart failure (HF) aiming to improve phenotyping focusing on HF with preserved left ventricular ejection fraction (HFpEF) pathophysiology.Methods and results New onset HF patients diagnosed in hospital or at outpatient HF clinics were included at five Stockholm hospitals 2015-2018 and characterized by N-terminal pro brain natriuretic peptide (NT-proBNP), biomarkers, echocardiography, and cardiac magnetic resonance imaging (subset). HFpEF [left ventricular ejection fraction (LVEF) >= 50%) was compared with HF with mildly reduced LVEF (HFmrEF; LVEF 41-49%) and with HF with reduced LVEF (HFrEF; LVEF <= 40%). We included 547 patients whereof HFpEF (n = 137; 25%), HFmrEF (n = 61; 11%), and HFrEF (n = 349; 64%). HFpEF patients were older (76; 70-81 years; median; interquartile range) than HFrEF (67; 58-74; P < 0.001), more often women (49% vs. 30%; P < 0.001), and had significantly higher comorbidity burden. They more often had atrial fibrillation, hypertension, and renal dysfunction. NT-proBNP was lower in HFpEF (896; 462-1645 ng/L) than in HFrEF (1160; 563-2370; P = 0.005). In HFpEF, left ventricular (LV) diameters and volumes were smaller (P < 0.001) and septa! and posterior wall thickness and relative wall thickness higher (P < 0.001). E/e >= 14 was present in 26% of HFpEF vs. 32% of HFrEF (P = 0.017) and left atrial volume index > 34 mL/m(2) in 57% vs. 61% (P = 0.040). HFmrEF patients were intermediary between HFpEF and HFrEF for LV mass, LV volumes, and RV volumes but had the highest proportion of left ventricular hypertrophy and the lowest proportion of elevated E/e.Conclusions Phenotype data in new onset HF patients recruited in a broad clinical setting showed that 25% had HFpEF, were older, more often women, and had greater comorbidity burden. PREFERS is well suited to further explore biomarker and imaging components of HFpEF pathophysiology and may contribute to the emerging knowledge of HF epidemiology.
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12. |
- Matan, Dmitri, et al.
(author)
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Extracellular vesicles in heart failure : A study in patients with heart failure with preserved ejection fraction or heart failure with reduced ejection fraction characteristics undergoing elective coronary artery bypass grafting
- 2022
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In: Frontiers in Cardiovascular Medicine. - : Frontiers Media S.A.. - 2297-055X. ; 9
-
Journal article (peer-reviewed)abstract
- AimsExtracellular vesicles (EVs) were investigated as potential biomarkers associated with heart failure (HF) pathophysiology in patients undergoing elective coronary artery bypass surgery characterized by HF phenotype. Materials and methodsPatients with preoperative proxy-diagnoses of HF types i.e., preserved (HFpEF; n = 19) or reduced ejection fraction (HFrEF; n = 20) were studied and compared to patients with normal left ventricular function (n = 42). EVs in plasma samples collected from the coronary sinus, an arterial line, and from the right atrium were analyzed by flow cytometry. We studied EVs of presumed cardiomyocyte origin [EVs exposing Connexin-43 + Caveolin-3 (Con43 + Cav3) and Connexin-43 + Troponin T (Con43 + TnT)], of endothelial origin [EVs exposing VE-Cadherin (VE-Cad)] and EVs exposing inflammatory markers [myeloperoxidase (MPO) or pentraxin3 (PTX3)]. ResultsMedian concentrations of EVs exposing Con43 + TnT and Con43 + Cav3 were approximately five to six times higher in coronary sinus compared to radial artery indicative of cardiac release. Patients with HFrEF had high trans-coronary gradients of both Con43 + TnT and Con43 + Cav3 EVs, whereas HFpEF had elevated gradients of Con43 + Cav3 EVs but lower gradients of Con43 + TnT. Coronary sinus concentrations of both Con43 + TnT and Con43 + Cav3 correlated significantly with echocardiographic and laboratory measures of HF. MPO-EV concentrations were around two times higher in the right atrium compared to the coronary sinus, and slightly higher in HFpEF than in HFrEF. EV concentrations of endothelial origin (VE-Cad) were similar in all three patient groups. ConclusionCon43 + TnT and Con43 + Cav3 EVs are released over the heart indicating cardiomyocyte origin. In HFrEF the EV release profile is indicative of myocardial injury and myocardial stress with elevated trans-coronary gradients of both Con43 + TnT and Con43 + Cav3 EVs, whereas in HFpEF the profile indicates myocardial stress with less myocardial injury.
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13. |
- Papamichail, A., et al.
(author)
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Compositionally graded channel HEMTs towards improved linearity for low-noise RF amplifiers
- 2022
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In: 2022 Compound Semiconductor Week, CSW 2022.
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Conference paper (peer-reviewed)abstract
- Although AlGaN/GaN HEMTs with high power and current gain have been demonstrated in RF device applications, at high signal operation they show an inherent non-linear behavior which leads to gain compression and signal distortion. Polarization-doped AlGaN/GaN HEMTs, with a compositionally graded channel enables a linear response improvement through formation of a 3-D electron gas. In this work, we develop the growth process for graded channel HEMTs in a hot-wall MOCVD reactor. Control of the grading profile is established through growth parameter tuning. Afterwards, analysis by EDS allows for precise determination of Al composition across the channel. Conventional and graded channel HEMT structures were fabricated and characterized. Furthermore, the sheet resistance, carrier density and mobility in HEMT structures with different grading profiles are compared and discussed. The conventional (non-graded) structure revealed the highest electron mobility of ~2350 cm2/V.s, which is among the highest values reported.
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14. |
- Persson, Anton E.O., et al.
(author)
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Reduced annealing temperature for ferroelectric HZO on InAs with enhanced polarization
- 2020
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In: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 116:6
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Journal article (peer-reviewed)abstract
- Deposition, annealing, and integration of ferroelectric Hf x Zr 1 - x O 2 (HZO) thin films on the high-mobility semiconductor InAs using atomic layer deposition are investigated. Electrical characterization reveals that the HZO films on InAs exhibit an enhanced remanent polarization compared to films formed on a reference TiN substrate, exceeding 20 μ C / cm 2 even down to an annealing temperature of 370 °C. For device applications, the thermal processes required to form the ferroelectric HZO phase must not degrade the high-κ/InAs interface. We find by evaluation of the capacitance-voltage characteristics that the electrical properties of the high-κ/InAs are not significantly degraded by the annealing process, and high-resolution transmission electron microscopy verifies a maintained sharp high-κ/InAs interface.
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15. |
- Persson, P. O.Å., et al.
(author)
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Tuning composition in graded AlGaN channel HEMTs toward improved linearity for low-noise radio-frequency amplifiers
- 2023
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In: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 122:15
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Journal article (peer-reviewed)abstract
- Compositionally graded channel AlGaN/GaN high electron mobility transistors (HEMTs) offer a promising route to improve device linearity, which is necessary for low-noise radio-frequency amplifiers. In this work, we demonstrate different grading profiles of a 10-nm-thick AlxGa1-xN channel from x = 0 to x = 0.1 using hot-wall metal-organic chemical vapor deposition (MOCVD). The growth process is developed by optimizing the channel grading and the channel-to-barrier transition. For this purpose, the Al-profiles and the interface sharpness, as determined from scanning transmission electron microscopy combined with energy-dispersive x-ray spectroscopy, are correlated with specific MOCVD process parameters. The results are linked to the channel properties (electron density, electron mobility, and sheet resistance) obtained by contactless Hall and terahertz optical Hall effect measurements coupled with simulations from solving self-consistently Poisson and Schrödinger equations. The impact of incorporating a thin AlN interlayer between the graded channel and the barrier layer on the HEMT properties is investigated and discussed. The optimized graded channel HEMT structure is found to have similarly high electron density (∼9 × 10 12 cm-2) as the non-graded conventional structure, though the mobility drops from ∼ 2360 cm2/V s in the conventional to ∼ 960 cm2/V s in the graded structure. The transconductance gm of the linearly graded channel HEMTs is shown to be flatter with smaller g m ′ and g m ″ as compared to the conventional non-graded channel HEMT implying improved device linearity.
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16. |
- Sällström, Johan, et al.
(author)
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High-protein-induced glomerular hyperfiltration is independent of the tubuloglomerular feedback mechanism and nitric oxide synthases
- 2010
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In: American Journal of Physiology. Regulatory Integrative and Comparative Physiology. - : American Physiological Society. - 0363-6119 .- 1522-1490. ; 299:5, s. R1263-R1268
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Journal article (peer-reviewed)abstract
- A high protein intake is associated with increased glomerular filtration rate (GFR), which has been suggested to be mediated by reduced signaling of the tubuloglomerular feedback (TGF) mechanism. Nitric oxide (NO) has been shown to contribute to high protein-induced glomerular hyperfiltration, but the specific NO synthase (NOS) isoform responsible is not clear. In this study, a model for high-proteininduced hyperfiltration in conscious mice was developed. Using this model, we investigated the role of TGF using adenosine A(1)-receptor knockout mice lacking the TGF mechanism. Furthermore, the role of the different NOS isoforms was studied using neuronal-, inducible-, and endothelial-NOS knockout mice, and furthermore, wild-type mice acutely administered with the unspecific NOS inhibitor N-omega-nitro-L-arginine methyl ester (100 mg/kg). GFR was measured consecutively in mice given a low-protein diet (8% casein) for 10 days, followed by a high-protein diet (50% casein) for 10 days. All mice developed high protein-induced hyperfiltration to a similar degree. These results demonstrate that high protein-induced glomerular hyperfiltration is independent of the TGF mechanism and NOS isoforms.
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17. |
- Aboulfadl, Hisham, 1986, et al.
(author)
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Alkali Dispersion in (Ag,Cu)(In,Ga)Se2 Thin Film Solar Cells - Insight from Theory and Experiment
- 2021
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In: ACS Applied Materials & Interfaces. - : American Chemical Society (ACS). - 1944-8252 .- 1944-8244. ; 13:6, s. 7188-7199
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Journal article (peer-reviewed)abstract
- Silver alloying of Cu(In,Ga)Se2 absorbers for thin film photovoltaics offers improvements in open-circuit voltage, especially when combined with optimal alkali-treatments and certain Ga concentrations. The relationship between alkali distribution in the absorber and Ag alloying is investigated here, combining experimental and theoretical studies. Atom probe tomography analysis is implemented to quantify the local composition in grain interiors and at grain boundaries. The Na concentration in the bulk increases up to ∼60 ppm for [Ag]/([Ag] + [Cu]) = 0.2 compared to ∼20 ppm for films without Ag and up to ∼200 ppm for [Ag]/([Ag] + [Cu]) = 1.0. First-principles calculations were employed to evaluate the formation energies of alkali-on-group-I defects (where group-I refers to Ag and Cu) in (Ag,Cu)(In,Ga)Se2 as a function of the Ag and Ga contents. The computational results demonstrate strong agreement with the nanoscale analysis results, revealing a clear trend of increased alkali bulk solubility with the Ag concentration. The present study, therefore, provides a more nuanced understanding of the role of Ag in the enhanced performance of the respective photovoltaic devices.
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18. |
- Adlercreutz, Patrick, et al.
(author)
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Enzymatic conversions of polar lipids. Principles, problems and solutions
- 2001
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In: Journal of Molecular Catalysis - B Enzymatic. - 1381-1177. ; 11:4-6, s. 173-178
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Research review (peer-reviewed)abstract
- This text provides a brief overview of the principles of enzymatic lipid conversion and some recent advances in the enzymatic conversion of glycerophospholipids and galactolipids. Lipases and phospholipases are used to exchange fatty acids or the polar group in the lipids. The reactions can be carried out either as hydrolysis-esterification sequences or as one-step transferase reactions. The scope and limitations of the different methods are discussed.
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19. |
- Ahlberg, Erik, et al.
(author)
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"Vi klimatforskare stödjer Greta och skolungdomarna"
- 2019
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In: Dagens nyheter (DN debatt). - 1101-2447.
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Journal article (pop. science, debate, etc.)abstract
- DN DEBATT 15/3. Sedan industrialiseringens början har vi använt omkring fyra femtedelar av den mängd fossilt kol som får förbrännas för att vi ska klara Parisavtalet. Vi har bara en femtedel kvar och det är bråttom att kraftigt reducera utsläppen. Det har Greta Thunberg och de strejkande ungdomarna förstått. Därför stödjer vi deras krav, skriver 270 klimatforskare.
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20. |
- Ahlgren-Moritz, Charlotte, et al.
(author)
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Vägen till samverkanssäkrad utbildning. [1] : Metoder och strategier
- 2016
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Book (other academic/artistic)abstract
- Universitet och högskolor bidrar till samhällsutvecklingen genom att forskningsbaserad kunskap tillämpas av olika aktörer i samhället. För att möta dagens och morgondagens samhällsutmaningar utgör således kunskapsutbyte och samverkan mellan lärosäten och samhället en värdefull möjlighet. Att ha starka relationer med samhällets aktörer identifieras också som viktigt i utvecklingen av ett internationellt starkt lärosäte.Samverkan i högre utbildning främjar samhällets förändringsförmåga och stärker utbildningens kvalitet, men samverkan förbereder också studenterna för ett livslångt lärande och underlättar övergången mellan utbildning och arbetsliv. Ett lärosäte i nära samverkan med aktörer i samhället är ett relevant lärosäte, det vill säga ett lärosäte som är till nytta för sin omvärld och för sina medarbetare och studenter.Ett grundläggande problem vad gäller möjligheterna att integrera samverkan i akademisk utbildning står att finna i statens fördelning av medel till lärosätena. De statliga medlen utgår nämligen i två separata anslag, ett vardera för de båda huvuduppdragen utbildning och forskning. Samverkan kan sägas ingå i bägge uppdragen. Till skillnad från forskningssamverkan finns det för utbildningssamverkan ingen särskild uppföljning och inte heller några ekonomiska incitament. Utvärdering av forskning och utbildning bör således breddas så att kvalitetsstärkande samverkansinslag också inkluderas i resursfördelningsprinciperna. Statens bristande strukturer för fördelning och uppföljning återspeglas i hur lärosätena fördelar resurser till och följer upp samverkan: lärare ges sällan resurser (i form av särskild tid) för att på ett pedagogiskt genomtänkt sätt kunna inkludera samverkansinslag i undervisningen; samverkan är sällan meriterande eller lönegrundande; och den utbildningssamverkan som bedrivs följs sällan upp – varken på institutions-, fakultets- eller lärosätesnivå. Samma sak kan sägas gälla på nationell nivå – det samverkande lärosätet erhåller inga extra anslag och det bestraffas ej heller för försummelse av detsamma. Att göra samverkan till en integrerad del av utbildningen innebär att samverkan bör ingå i de pedagogiska modeller som lärare använder för att leda studenternas kunskapsutveckling mot de mål som finns angivna i kurs- och utbildningsplaner. Det betyder också att arbetet med samverkan bör inkluderas i processer för styrning, planering och uppföljning av utbildning och undervisning på såväl kurs- och programnivå som på institutions-, fakultets- och lärosätesnivå. Att göra samverkan till en integrerad del av utbildningen är att sträva mot att externa aktörer ska bli en självklar del i den dagliga verksamheten – för studenter såväl som för medarbetare och för de organisationer man samverkar med. För att svenska lärosäten ska ges en realistisk möjlighet att göra samverkan till en integrerad del av utbildningsverksamheten krävs det framför allt följande:att politiker och departement utformar ett fördelningssystem där framgångsrika samverkansinsatser inom utbildningen leder till en förstärkning av resursbasen på lärosätena;att lärosätesledningar tar tydlig ställning för samverkansfrågan i sina strategiska styrdokument och att samverkan införs i lärosätenas kvalitetssäkringssystem för utbildning, samt att lärosätena inför system för att styra och följa upp samverkan i utbildningen på lärosätesövergripande nivå;att ledningen för fakulteter, institutioner eller motsvarande omsätter lärosätets strategiska åtaganden i handlingsplaner och lokala styrdokument samt utformar system för dokumentation, styrning och uppföljning av samverkan i utbildningsprogram;att lärare samt kurs- och programansvariga inför samverkan i utbildningens styrande dokument (t.ex. kurs- och utbildningsplaner) samt i den ordinarie undervisningsverksamheten.Dessutom bör lärosätena – både gemensamt men också vart och ett för sig – införa system och karriärvägar där medarbetares insatser i det vardagliga samverkansarbetet uppmärksammas och belönas.Mot bakgrund av detta kan man konstatera att det är angeläget att lärosätenas strategiska arbete avseende utveckling och uppföljning av samverkan i utbildningen vidareutvecklas. Men, med vilka verktyg, var i verksamheten och på vilka sätt?I följande skrift samlas erfarenheter och goda exempel gjorda inom ramen för ett flerårigt lärosätesövergripande samarbetsprojekt, Samverkanssäkrade utbildningsprogram, där utgångspunkten har varit att identifiera strategier och metoder för att integrera samverkan i utbildningsprogram. Målet har varit att undersöka och beskriva hur samverkan kan vara ett medel som bidrar till att stärka utbildningens kvalitet och relevans, samt ge förslag på hur vägen till samverkanssäkrad utbildning kan se ut.Den centrala slutsatsen är att samverkan, när den är en integrerad del av utbildningen, bidrar till kvalitet och säkerställer att utbildningen blir till nytta för samhället. Det finns också andra vinster med att bedriva ett systematiskt samverkansarbete, till exempel att det leder till pedagogisk utveckling för undervisande personal, att det ökar förutsättningarna för ett utmaningsbaserat lärande med studenten i centrum, att det underlättar övergången från studier till arbetsliv, och att det möjliggör fördjupade relationer med den värld lärosätet finns i. Resan mot samverkanssäkrad utbildning är, med andra ord, mödan väl värd.
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21. |
- Ahlgren-Moritz, Charlotte, et al.
(author)
-
Vägen till samverkanssäkrad utbildning. [2] : Möjligheter och utmaningar
- 2016
-
Book (other academic/artistic)abstract
- Universitet och högskolor bidrar till samhällsutvecklingen genom att forskningsbaserad kunskap tillämpas av olika aktörer i samhället. För att möta dagens och morgondagens samhällsutmaningar utgör således kunskapsutbyte och samverkan mellan lärosäten och samhället en värdefull möjlighet. Att ha starka relationer med samhällets aktörer identifieras också som viktigt i utvecklingen av ett internationellt starkt lärosäte.Samverkan i högre utbildning främjar samhällets förändringsförmåga och stärker utbildningens kvalitet, men samverkan förbereder också studenterna för ett livslångt lärande och underlättar övergången mellan utbildning och arbetsliv. Ett lärosäte i nära samverkan med aktörer i samhället är ett relevant lärosäte, det vill säga ett lärosäte som är till nytta för sin omvärld och för sina medarbetare och studenter.Ett grundläggande problem vad gäller möjligheterna att integrera samverkan i akademisk utbildning står att finna i statens fördelning av medel till lärosätena. De statliga medlen utgår nämligen i två separata anslag, ett vardera för de båda huvuduppdragen utbildning och forskning. Samverkan kan sägas ingå i bägge uppdragen. Till skillnad från forskningssamverkan finns det för utbildningssamverkan ingen särskild uppföljning och inte heller några ekonomiska incitament. Utvärdering av forskning och utbildning bör således breddas så att kvalitetsstärkande samverkansinslag också inkluderas i resursfördelningsprinciperna. Statens bristande strukturer för fördelning och uppföljning återspeglas i hur lärosätena fördelar resurser till och följer upp samverkan: lärare ges sällan resurser (i form av särskild tid) för att på ett pedagogiskt genomtänkt sätt kunna inkludera samverkansinslag i undervisningen; samverkan är sällan meriterande eller lönegrundande; och den utbildningssamverkan som bedrivs följs sällan upp – varken på institutions-, fakultets- eller lärosätesnivå. Samma sak kan sägas gälla på nationell nivå – det samverkande lärosätet erhåller inga extra anslag och det bestraffas ej heller för försummelse av detsamma. Att göra samverkan till en integrerad del av utbildningen innebär att samverkan bör ingå i de pedagogiska modeller som lärare använder för att leda studenternas kunskapsutveckling mot de mål som finns angivna i kurs- och utbildningsplaner. Det betyder också att arbetet med samverkan bör inkluderas i processer för styrning, planering och uppföljning av utbildning och undervisning på såväl kurs- och programnivå som på institutions-, fakultets- och lärosätesnivå. Att göra samverkan till en integrerad del av utbildningen är att sträva mot att externa aktörer ska bli en självklar del i den dagliga verksamheten – för studenter såväl som för medarbetare och för de organisationer man samverkar med. För att svenska lärosäten ska ges en realistisk möjlighet att göra samverkan till en integrerad del av utbildningsverksamheten krävs det framför allt följande:att politiker och departement utformar ett fördelningssystem där framgångsrika samverkansinsatser inom utbildningen leder till en förstärkning av resursbasen på lärosätena;att lärosätesledningar tar tydlig ställning för samverkansfrågan i sina strategiska styrdokument och att samverkan införs i lärosätenas kvalitetssäkringssystem för utbildning, samt att lärosätena inför system för att styra och följa upp samverkan i utbildningen på lärosätesövergripande nivå;att ledningen för fakulteter, institutioner eller motsvarande omsätter lärosätets strategiska åtaganden i handlingsplaner och lokala styrdokument samt utformar system för dokumentation, styrning och uppföljning av samverkan i utbildningsprogram;att lärare samt kurs- och programansvariga inför samverkan i utbildningens styrande dokument (t.ex. kurs- och utbildningsplaner) samt i den ordinarie undervisningsverksamheten.Dessutom bör lärosätena – både gemensamt men också vart och ett för sig – införa system och karriärvägar där medarbetares insatser i det vardagliga samverkansarbetet uppmärksammas och belönas.Mot bakgrund av detta kan man konstatera att det är angeläget att lärosätenas strategiska arbete avseende utveckling och uppföljning av samverkan i utbildningen vidareutvecklas. Men, med vilka verktyg, var i verksamheten och på vilka sätt?I följande skrift samlas erfarenheter och goda exempel gjorda inom ramen för ett flerårigt lärosätesövergripande samarbetsprojekt, Samverkanssäkrade utbildningsprogram, där utgångspunkten har varit att identifiera strategier och metoder för att integrera samverkan i utbildningsprogram. Målet har varit att undersöka och beskriva hur samverkan kan vara ett medel som bidrar till att stärka utbildningens kvalitet och relevans, samt ge förslag på hur vägen till samverkanssäkrad utbildning kan se ut.Den centrala slutsatsen är att samverkan, när den är en integrerad del av utbildningen, bidrar till kvalitet och säkerställer att utbildningen blir till nytta för samhället. Det finns också andra vinster med att bedriva ett systematiskt samverkansarbete, till exempel att det leder till pedagogisk utveckling för undervisande personal, att det ökar förutsättningarna för ett utmaningsbaserat lärande med studenten i centrum, att det underlättar övergången från studier till arbetsliv, och att det möjliggör fördjupade relationer med den värld lärosätet finns i. Resan mot samverkanssäkrad utbildning är, med andra ord, mödan väl värd.
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22. |
- Al-Mashhadi, Ammar, et al.
(author)
-
Changes of arterial pressure following relief of obstruction in adults with hydronephrosis
- 2018
-
In: Upsala Journal of Medical Sciences. - : Uppsala Medical Society. - 0300-9734 .- 2000-1967. ; 123:4, s. 216-224
-
Journal article (peer-reviewed)abstract
- Background: As much as 20% of all cases of hypertension are associated with kidney malfunctions. We have previously demonstrated in animals and in pediatric patients that hydronephrosis causes hypertension, which was attenuated by surgical relief of the ureteropelvic junction (UPJ) obstruction. This retrospective cohort study aimed to investigate: (1) the proposed link between hydronephrosis, due to UPJ obstruction, and elevated arterial pressure in adults; and (2) if elevated blood pressure in patients with hydronephrosis might be another indication for surgery.Materials and methods: Medical records of 212 patients undergoing surgical management of hydronephrosis, due to UPJ obstruction, between 2000 and 2016 were assessed. After excluding patients with confounding conditions and treatments, paired arterial pressures (i.e. before/after surgery) were compared in 49 patients (35 years old; 95% CI 29–39). Split renal function was evaluated by using mercaptoacetyltriglycine (MAG3) renography before surgical management of the hydronephrotic kidney.Results: Systolic (−11 mmHg; 95% CI 6–15 mmHg), diastolic (−8 mmHg; 95% CI 4–11 mmHg), and mean arterial (-9 mmHg; 95% CI 6–12) pressures were significantly reduced after relief of the obstruction (p < 0.001). Split renal function of the hydronephrotic kidney was 39% (95% CI 37–41). No correlations were found between MAG3 and blood pressure level before surgery or between MAG3 and the reduction of blood pressure after surgical management of the UPJ obstruction.Conclusions: In adults with hydronephrosis, blood pressure was reduced following relief of the obstruction. Our findings suggest that elevated arterial pressure should be taken into account as an indication to surgically correct hydronephrosis.
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23. |
- Al-Mashhadi, Ammar Nadhom Farman, et al.
(author)
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Changes in arterial pressure and markers of nitric oxide homeostasis and oxidative stress following surgical correction of hydronephrosis in children
- 2018
-
In: Pediatric nephrology (Berlin, West). - : Springer. - 0931-041X .- 1432-198X. ; 33:4, s. 639-649
-
Journal article (peer-reviewed)abstract
- Objective Recent clinical studies have suggested an increased risk of elevated arterial pressure in patients with hydronephrosis. Animals with experimentally induced hydronephrosis develop hypertension, which is correlated to the degree of obstruction and increased oxidative stress. In this prospective study we investigated changes in arterial pressure, oxidative stress, and nitric oxide (NO) homeostasis following correction of hydronephrosis.Methods Ambulatory arterial pressure (24 h) was monitored in pediatric patients with hydronephrosis (n = 15) before and after surgical correction, and the measurements were compared with arterial pressure measurements in two control groups, i.e. healthy controls (n = 8) and operated controls (n = 8). Markers of oxidative stress and NO homeostasis were analyzed in matched urine and plasma samples.Results The preoperative mean arterial pressure was significantly higher in hydronephrotic patients [83 mmHg; 95% confidence interval (CI) 80–88 mmHg] than in healthy controls (74 mmHg; 95% CI 68–80 mmHg; p < 0.05), and surgical correction of ureteral obstruction reduced arterial pressure (76 mmHg; 95% CI 74–79 mmHg; p < 0.05). Markers of oxidative stress (i.e., 11- dehydroTXB2, PGF2α, 8-iso-PGF2α, 8,12-iso-iPF2α-VI) were significantly increased (p < 0.05) in patients with hydronephrosis compared with both control groups, and these were reduced following surgery (p < 0.05). Interestingly, there was a trend for increased NO synthase activity and signaling in hydronephrosis, which may indicate compensatory mechanism(s).Conclusion This study demonstrates increased arterial pressure and oxidative stress in children with hydronephrosis compared with healthy controls, which can be restored to normal levels by surgical correction of the obstruction. Once reference data on ambulatory blood pressure in this young age group become available, we hope cut-off values can be defined for deciding whether or not to correct hydronephrosis surgically.Keywords Blood pressure . Hydronephrosis . Hypertension . Nitric oxide . Oxidative stress . Ureteral obstruction
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24. |
- Al-Mashhadi, Ammar Nadhom Farman, et al.
(author)
-
Surgical treatment reduces blood pressure in children with unilateral congenital hydronephrosis
- 2015
-
In: Journal of Pediatric Urology. - : Elsevier BV. - 1477-5131 .- 1873-4898. ; 11:2, s. 91.e1-91.e6
-
Journal article (peer-reviewed)abstract
- Objective Renal disorders can cause hypertension, but less is known about the influence of hydronephrosis on blood pressure. Hydronephrosis due to pelvo-ureteric junction obstruction (PUJO) is a fairly common condition (incidence in newborns of 0.5-1%). Although hypertensive effects of hydronephrosis have been suggested, this has not been substantiated by prospective studies in humans [1-3]. Experimental studies with PUJO have shown that animals with induced hydronephrosis develop salt-sensitive hypertension, which strongly correlate to the degree of obstruction [4-7]. Moreover, relief of the obstruction normalized blood pressure [8]. In this first prospective study our aim was to study the blood pressure pattern in pediatric patients with hydronephrosis before and after surgical correction of the ureteral obstruction. Specifically, we investigated if preoperative blood pressure is reduced after surgery and if split renal function and renographic excretion curves provide any prognostic information. Patients and methods Twelve patients with unilateral congenital hydronephrosis were included in this prospective study. Ambulatory blood pressure (24 h) was measured preoperatively and six months after surgery. Preoperative evaluations of bilateral renal function by Tc99m-MAG3 scintigraphy, and renography curves, classified according to O'Reilly, were also performed. Results As shown in the summary figure, postoperative systolic (103 +/- 2 mmHg) and diastolic (62 +/- 2 mmHg) blood pressure were significantly lower than those obtained preoperatively (110 +/- 4 and 69 +/- 2 mmHg, respectively), whereas no changes in circadian variation or pulse pressure were observed. Renal functional share of the hydronephrotic kidney ranged from 11 to 55%. There was no correlation between the degree of renal function impairment and the preoperative excretory pattern, or between the preoperative excretory pattern and the blood pressure reduction postoperatively. However, preoperative MAG3 function of the affected kidney correlated with the magnitude of blood pressure change after surgery. Discussion Correction of the obstruction lowered blood pressure, and the reduction in blood pressure appeared to correlate with the degree of renal functional impairment, but not with the excretory pattern. Thus, in the setting of hypertension, it appears that the functional share of the hydronephrotic kidney should be considered an indicator of the need for surgery, whereas the renography curve is less reliable. The strength of the present study is the prospective nature and that ambulatory blood pressure monitoring was used. Future longitudinal prolonged follow-up studies are warranted to confirm the present findings, and to understand if a real nephrogenic hypertension with potential necessity of treatment will develop. Conclusion This novel prospective study in patients with congenital hydronephrosis demonstrates a reduction in blood pressure following relief of the obstruction. Based on the present results, we propose that the blood pressure level should also be taken into account when deciding whether to correct hydronephrosis surgically or not.
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25. |
- Andersson, Mattias, et al.
(author)
-
Conformation sensitive charge transport in conjugated polymers
- 2013
-
In: Applied Physics Letters. - : American Institute of Physics (AIP). - 0003-6951 .- 1077-3118. ; 103:21, s. 213303-
-
Journal article (peer-reviewed)abstract
- Temperature dependent charge carrier mobility measurements using field effect transistors and density functional theory calculations are combined to show how the conformation dependent frontier orbital delocalization influences the hole-and electron mobilities in a donor-acceptor based polymer. A conformationally sensitive lowest unoccupied molecular orbital results in an electron mobility that decreases with increasing temperature above room temperature, while a conformationally stable highest occupied molecular orbital is consistent with a conventional hole mobility behavior and also proposed to be one of the reasons for why the material works well as a hole transporter in amorphous bulk heterojunction solar cells.
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26. |
- Arnqvist, Lisa, 1970-, et al.
(author)
-
Overexpression of CYP710A1 and CYP710A4 in transgenic Arabidopsis plants increases the level of stigmasterol at the expense of sitosterol
- 2008
-
In: Planta. - : Springer Science and Business Media LLC. - 0032-0935 .- 1432-2048. ; 227:2, s. 309-317
-
Journal article (peer-reviewed)abstract
- Sitosterol and stigmasterol are major sterols in vascular plants. An altered stigmasterol:sitosterol ratio has been proposed to influence the properties of cell membranes, particularly in relation to various stresses, but biosynthesis of stigmasterol is poorly understood. Recently, however, Morikawa et al. (Plant Cell 18:1008–1022, 2006) showed in Arabidopsis thaliana that synthesis of stigmasterol and brassicasterol is catalyzed by two separate sterol C-22 desaturases, encoded by the genes CYP710A1 and CYP710A2, respectively. The proteins belong to a small cytochrome P450 subfamily having four members, denoted by CYP710A1-A4, and are related to the yeast sterol C-22 desaturase Erg5p acting in ergosterol synthesis. Here, we report on our parallel investigation of the Arabidopsis CYP710A family. To elucidate the function of CYP710A proteins, transgenic Arabidopsis plants were generated overexpressing CYP710A1 and CYP710A4. Compared to wild-type plants, both types of transformant displayed a normal phenotype, but contained increased levels of free stigmasterol and a concomitant decrease in the level of free sitosterol. CYP710A1 transformants also displayed higher levels of esterified forms of stigmasterol, cholesterol, 24-methylcholesterol and isofucosterol. The results confirm the findings of Morikawa et al. (Plant Cell 18:1008–1022, 2006) regarding the function of CYP710A1 in stigmasterol synthesis, and show that CYP710A4 also has this capacity. Furthermore, our results suggest that an increased stigmasterol level alone is sufficient to stimulate esterification of other major sterols.
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27. |
- Aronsson, Mattias, et al.
(author)
-
Cost-effectiveness of endovascular thrombectomy in patients with acute ischemic stroke.
- 2016
-
In: Neurology. - : American Academy of neurology. - 0028-3878 .- 1526-632X. ; 86:11, s. 1053-9
-
Journal article (peer-reviewed)abstract
- Objective:To evaluate the cost-effectiveness of adding endovascular thrombectomy to standard care in patients with acute ischemic stroke.Methods:The cost-effectiveness analysis of endovascular thrombectomy in patients with acute ischemic stroke was based on a decision-analytic Markov model. Primary outcomes from ESCAPE, Extending the Time for Thrombolysis in Emergency Neurological Deficits-Intra-Arterial (EXTEND-IA), Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands (MR CLEAN), Endovascular Revascularization With Solitaire Device Versus Best Medical Therapy in Anterior Circulation Stroke Within 8 Hours (REVASCAT), and Solitaire with the Intention for Thrombectomy as Primary Endovascular Treatment for Acute Ischemic Stroke (SWIFT PRIME) along with data from published studies and registries were used in this analysis. We used a health care payer perspective and a lifelong time horizon to estimate costs and effects.Results:The model showed that adding thrombectomy with stent retrievers to guideline-based care (including IV thrombolysis) resulted in a gain of 0.40 life-years and 0.99 quality-adjusted life-years along with a cost savings of approximately $221 per patient. The sensitivity analysis showed that the results were not sensitive to changes in uncertain parameters or assumptions.Conclusions:Adding endovascular treatment to standard care resulted in substantial clinical benefits at low costs. The results were consistent throughout irrespective of whether data from ESCAPE, EXTEND-IA, MR CLEAN, REVASCAT, or SWIFT PRIME were used in this model.
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28. |
- Aronsson, Mattias, et al.
(author)
-
Kostnadseffektiviteten av trombektomibehandling vid akut ischemisk stroke
- 2016
-
In: Neurologi i Sverige. - 2000-8538. ; 3
-
Journal article (peer-reviewed)abstract
- Flera randomiserade studier har visat på mycket goda kortsiktiga medicinska effekter av trombektomibehandling som tillägg till standardbehandling. Frågan återstår dock om den långsiktiga nyttan kan rättfärdiga de höga kostnaderna för denna behandling. Mattias Aronsson, Josefine Persson, Christian Blomstrand, Per Wester och Lars-Åke Levin beskriver här resultaten från sin hälsoekonomiska studie, som publicerades i tidskriften Neurology tidigare i år.
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29. |
- Athle, Robin, et al.
(author)
-
Effects of TiN Top Electrode Texturing on Ferroelectricity in Hf1-xZrxO2
- 2021
-
In: ACS applied materials & interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 13:9, s. 11089-11095
-
Journal article (peer-reviewed)abstract
- Ferroelectric memories based on hafnium oxide are an attractive alternative to conventional memory technologies due to their scalability and energy efficiency. However, there are still many open questions regarding the optimal material stack and processing conditions for reliable device performance. Here, we report on the impact of the sputtering process conditions of the commonly used TiN top electrode on the ferroelectric properties of Hf1-xZrxO2. By manipulating the deposition pressure and chemistry, we control the preferential orientation of the TiN grains between (111) and (002). We observe that (111) textured TiN is superior to (002) texturing for achieving high remanent polarization (Pr). Furthermore, we find that additional nitrogen supply during TiN deposition leads to >5× greater endurance, possibly by limiting the scavenging of oxygen from the Hf1-xZrxO2 film. These results help explain the large Pr variation reported in the literature for Hf1-xZrxO2/TiN and highlights the necessity of tuning the top electrode of the ferroelectric stack for successful device implementation.
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30. |
- Athle, Robin, et al.
(author)
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Improved Endurance of Ferroelectric HfxZr1–xO2 Integrated on InAs Using Millisecond Annealing
- 2022
-
In: Advanced Materials Interfaces. - : Wiley. - 2196-7350. ; 9:27
-
Journal article (peer-reviewed)abstract
- Ferroelectric HfxZr1–xO2 (HZO) is typically achieved by crystallization of an amorphous thin film via rapid thermal processing (RTP) at time scales of seconds to minutes. For integration on III–V semiconductors, this approach can severely degrade the sensitive HZO/III–V interface. To evaluate whether a reduced thermal budget can improve the interface quality, millisecond duration thermal anneals are utilized using a flash lamp annealer (FLA) on HZO/InAs capacitors. Through thorough electrical characterization such as polarization hysteresis, endurance, and capacitance-voltage measurements, as well as synchrotron-based chemical interface characterization, the FLA and RTP treatments are compared and the FLA results are found in lower interface defect density and higher endurance, but also have generally lower remanent polarization (Pr) compared to RTP. Additionally, ways to achieve high Pr and low interface defect density using multiple lower energy flashes, as well as by pre-crystallization during the ALD growth step are investigated. Using FLA, Pr exceeding 20 µC cm−2 is achieved, with extended endurance properties compared to RTP treatment and a considerably decreased defect density, indicative of a higher quality HZO/InAs interface. This work presents valuable insight into the successful integration of ferroelectric HZO on low thermal budget III–V semiconductors.
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31. |
- Athle, Robin, et al.
(author)
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Top Electrode Engineering for Freedom in Design and Implementation of Ferroelectric Tunnel Junctions Based on Hf1- xZrxO2
- 2022
-
In: ACS Applied Electronic Materials. - : American Chemical Society (ACS). - 2637-6113. ; 4:3, s. 1002-1009
-
Journal article (peer-reviewed)abstract
- Ferroelectric tunnel junctions (FTJs) based on ultrathin HfO2 have great potential as a fast and energy-efficient memory technology compatible with complementary metal oxide semiconductors. FTJs consist of a ferroelectric film sandwiched between two distinct electrodes, the properties of which are intricately linked to the electrical properties of the FTJs. Here we utilize a W crystallization electrode (CE) to achieve a high and reproducible remanent polarization, combined with a metal replacement process in which the W is carefully removed and replaced by another top electrode (TE). In this way we separate the ferroelectric film properties from the device design and can thereby evaluate the effect of the TE work function (WF) and conduction band electron density (ne) on the tunneling electroresistance (TER) and device reliability. We compare FTJs designed with a TiN bottom electrode and W, Cr, or Ni TE and find that the use of high electron density metals such as Ni or Cr as TE allows for an improved TER, albeit at the cost of reliability due to a large built-in electric field. To bypass this effect, a bilayer Cr/Ni TE is implemented, which allows for a high TER and minimal built-in field, leading to excellent retention and endurance beyond 108 cycles. The results presented here thus highlight a process flow for reliable design and implementation of FTJs.
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32. |
- Aurand, B., et al.
(author)
-
Manipulation of the spatial distribution of laser-accelerated proton beams by varying the laser intensity distribution
- 2016
-
In: Physics of Plasmas. - : AIP Publishing. - 1089-7674 .- 1070-664X. ; 23:2
-
Journal article (peer-reviewed)abstract
- We report on a study of the spatial profile of proton beams produced through target normal sheath acceleration using flat target foils and changing the laser intensity distribution on the target front surface. This is done by either defocusing a single laser pulse or by using a split-pulse setup and irradiating the target with two identical laser pulses with variable spatial separation. The resulting proton beam profile and the energy spectrum are recorded as functions of the focal spot size of the single laser pulse and of the separation between the two pulses. A shaping of the resulting proton beam profile, related to both an increase in flux of low-energy protons in the target normal direction and a decrease in their divergence, in one or two dimensions, is observed. The results are explained by simple modelling of rear surface sheath field expansion, ionization, and projection of the resulting proton beam.
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33. |
- Bahar, Bahram, et al.
(author)
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Developing A-GPS as a Student Project
- 2006
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Reports (pop. science, debate, etc.)abstract
- The project consists of ten fourth-year computer science students at Uppsala University developing an A-GPS (Assisted-GPS) system. During the fall term of 2005 the students have developed a module for GPS-calculations in a GSM-network and an application that demonstrates a possible way of using the calculations module. This paper describes the design, the development process and the results of the project.
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34. |
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Barnstugan
- 2015
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Book (other academic/artistic)abstract
- Boken är en del av projektet Barnstugan. Boken redogör för en konstnärlig undersökning av två arkitektoniska projekt från slutet av 60-talet. Husen är ett typdaghemsprojekt för Stockholm stad samt Ingmar Bergmans bostad på Fårö. Husen sammanlänkas av det kontor (Abramsons arkitektkontor) som under samma tid projekterade husen. Genom att se på liknelser och skillnader, fysiska och innehållsliga, vill undersöks relationen mellan kollektiv och individ. Till boken har ett antal personer bjudits in att reflektera kring de tematiker projektet tangerar.
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35. |
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36. |
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37. |
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38. |
- Belting, Mattias, et al.
(author)
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Tumor attenuation by combined heparan sulfate and polyamine depletion.
- 2002
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In: Proceedings of the National Academy of Sciences. - 1091-6490. ; 99:1, s. 371-376
-
Journal article (peer-reviewed)abstract
- Cells depend on polyamines for growth and their depletion represents a strategy for the treatment of cancer. Polyamines assemble de novo through a pathway sensitive to the inhibitor, alpha-difluoromethylornithine (DFMO). However, the presence of cell-surface heparan sulfate proteoglycans may provide a salvage pathway for uptake of circulating polyamines, thereby sparing cells from the cytostatic effect of DFMO. Here we show that genetic or pharmacologic manipulation of proteoglycan synthesis in the presence of DFMO inhibits cell proliferation in vitro and in vivo. In cell culture, mutant cells lacking heparan sulfate were more sensitive to the growth inhibitory effects of DFMO than wild-type cells or mutant cells transfected with the cDNA for the missing biosynthetic enzyme. Moreover, extracellular polyamines did not restore growth of mutant cells, but completely reversed the inhibitory effect of DFMO in wild-type cells. In a mouse model of experimental metastasis, DFMO provided in the water supply also dramatically diminished seeding and growth of tumor foci in the lungs by heparan sulfate-deficient mutant cells compared with the controls. Wild-type cells also formed tumors less efficiently in mice fed both DFMO and a xylose-based inhibitor of heparan sulfate proteoglycan assembly. The effect seemed to be specific for heparan sulfate, because a different xyloside known to affect only chondroitin sulfate did not inhibit tumor growth. Hence, combined inhibition of heparan sulfate assembly and polyamine synthesis may represent an additional strategy for cancer therapy.
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39. |
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40. |
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41. |
- Berglund, Martin, 1981-
(author)
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Avräkningsmetoden : En skatterättslig studie om undvikande av internationell dubbelbeskattning
- 2013
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Doctoral thesis (other academic/artistic)abstract
- The territorial scope of modern income tax systems frequently leads to the occurrence of international double taxation, i.e., that the same income is taxed in two or more states. In cases of international double taxation, a foreign tax credit may be given by applying either the method article in Swedish tax treaties or the unilateral Foreign Tax Credit Act. The foreign tax credit method seeks to eliminate double taxation or, in other words, to achieve single taxation. In principle, the taxpayer’s residence state has the responsibility to credit foreign taxes which have been imposed because the income source is located abroad.The overall aim of this thesis is to study the Swedish foreign tax credit method in order to arrive at an understanding of the method as a whole. To achieve this aim, a question is posed, namely ”which concept of double taxation characterizes the foreign tax credit method?” The thesis is divided into three parts. The first part contains a reading of the historical and conceptual background of the phenomenon of international double taxation and the foreign tax credit method. It also consists of a study of the general systematic and territorial aspects of the foreign tax credit method. The second part deals with how to identify such international double taxation which the foreign tax credit method is aimed at eliminating. The third part concerns how the foreign tax credit method seeks to achieve single taxation in a situation where international double taxation has been identified. The last two parts corresponds to the two essential elements of the foreign tax credit method.When interpreting the foreign tax credit method, the concept of double taxation is related to fundamental concepts of modern income tax law, such as tax subject, tax object, and income tax. The classical concept of international double taxation has some relevance for the Swedish foreign tax credit method, although distinctive features of the Swedish tax system require special considerations. Regarding the second essential element of the foreign tax credit method, the achievement of single taxation, an important aspect is also to consider how different ways of eliminating double taxation affect the relationship between the residence state and the source state.
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42. |
- Bhattacharya, Prosun, et al.
(author)
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Temporal and seasonal variability of arsenic in drinking water wells in Matlab, southeastern Bangladesh : A preliminary evaluation on the basis of a 4 year study
- 2011
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In: Journal of Environmental Science and Health. Part A. - : Informa UK Limited. - 1093-4529 .- 1532-4117. ; 46:11, s. 1177-1184
-
Journal article (peer-reviewed)abstract
- Temporal and seasonal variability of As concentrations in groundwater were evaluated in As-affected areas of Matlab, southeastern Bangladesh. Groundwater samples from 61 randomly selected tubewells were analyzed for As concentrations over a period of three years and four months (from July 2002 to November 2005) and monitored seasonally (three times a year). The mean As concentrations in the sampled tubewells decreased from 153 to 123 mu g/L during July 2002 to November 2005. Such changes were pronounced in tubewells with As concentration >50 mu g/L than those with As concentrations <50 mu g/L. Similarly, individual wells revealed temporal variability, for example some wells indicated a decreasing trend, while some other wells indicated stable As concentration during the monitoring period. The mean As concentrations were significantly higher in Matlab North compared with Matlab South. The spatial variations in the mean As concentrations may be due to the differences in local geological conditions and groundwater flow patterns. The variations in mean As concentrations were also observed in shallow (<40 m) and deep (>40 m) wells. However, to adequately evaluate temporal and seasonal variability of As concentration, it is imperative to monitor As concentrations in tubewells over a longer period of time. Such long-term monitoring will provide important information for the assessment of human health risk and the sustainability of safe drinking water supplies.
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43. |
- Bogatic, Wirginia, 1969-
(author)
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Exilens dilemma: att stanna eller att återvända : Beslut i Sverige av polska kvinnor som överlevde KZ-lägret Ravensbrück och räddades till Sverige 1945-1947
- 2010
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Doctoral thesis (other academic/artistic)abstract
- This thesis is about the intersection of great narratives and individual decisions. In the intersection, the dilemma of exile is discussed: to remain in exile or return to one’s homeland. The decision to remain or return was made by the surviving Polish female concentration camp prisoners that were brought back to Sweden in 1945 with the Red Cross rescue operation.The women’s decisions have been contextualized by being placed against the political, social and economic upheavals that took place primarily in Poland, but also partly in Sweden, as well as in the international environment with which the new Poland had to form a relationship following the Second World War.The thesis moves between three levels: the micro level, comprising the individuals, their choices and experiences; the macro level, including the surrounding social, economic and political structures; the meso level, which merges the individual, her network and the state. The theoretical framework is on the one hand based on Reinhart Koselleck’s concepts of “realm of experience” and “expectations” that structure the time horizon and refer to the universal, and on the other hand, the sociological concept of generations and Svante Lundberg's model of exile with the concepts of Circumstance, Frame and Meaning. Both Koselleck and Lundberg focus on the individual / group and structural context. Sources used have been material from the Swedish Government and the two Polish governments and their agencies. In addition, a number of Polish and Swedish newspapers published during the period 1945-1947 as well as material from the Polish Source Institute in Lund (PIZ) have been studied. Thirteen in-depth interviews with the surviving women (both in Poland and Sweden) have been carried out, resulting in so-called life stories, with the objective of providing an answer to the question of why some of them remained in Sweden after the war while others returned to Poland. In the women's life stories, some themes can be distinguished: the common realm of experience, being adherent to the same sociological generation with a manifest collective memory (which in part developed differently depending on their decisions to remain or return), a link between war and captivity and expectations for the future. Otherwise, the life stories highlight the women's construction of identity, which is affected by growing up in the between-war Poland, the time during World War II and the occupation. It also reveals that these experiences influenced their decision: remaining and returning.
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44. |
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45. |
- Broberg, Thomas, et al.
(author)
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An electricity market in transition : demand flexibility and preference heterogeneity
- 2015
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Reports (other academic/artistic)abstract
- In a recent report to the Swedish Energy Markets Inspectorate (Broberg et al., 2014) consumer behavior and consumer flexibility concerning energy use were analyzed. Two main conclusions were drawn. First, electricity consumption follows a regular pattern over the day, week, and year, which to a large extent reflects household living patterns and climate variations over the year. Second, the average household needs a substantial economic compensation to voluntarily reschedule its electricity use away from peak demand hours. The required compensations were found to be far higher than the economic incentives households face today when exposed to real-time pricing. In addition, it was found that households are more flexible in the use of electricity for heating than in the use of electrical appliances. Finally, households were found to be more flexible during the morning peak hours than during the evening hours. These findings led to the overall conclusion that both the possibilities and incentives are such that we cannot expect any substantial change in energy use patterns from technical reforms that creates incentives for demand response in line with the current price variation on the wholesale market for electricity.In the above-mentioned report we also analyzed people’s attitudes towards information dissemination. We concluded that many households do not wish to have their electricity use scrutinized by experts and other households. We found that people, on average, required a compensation to allow such information sharing. Again, new technologies open for various demand response policies, although it does not necessarily imply substantially higher demand flexibility. New technologies need to be combined with consumer interest to be successful in a market economy.The overall objective of the current report is to further scrutinize consumer behavior and flexibility. The first part focuses on Swedish households’ choice of electricity supplier contracts. Specifically, we analyze what types of households choose a fixed price contract. 1 The choice of contract implicitly reveals a consumer’s flexibility since a fixed price contract works as an insurance against price variation. So, by studying what type of households chose a fixed price contract we are able to infer on which type of households are relatively inflexible. This part of the analysis is policy relevant since it touches on the question of what to expect from real-time pricing reforms. A central question is whether a household who uses relatively more electricity is more likely to have a fixed price contract. If this is the case, future access to real-time pricing and a greater price variation may not be a guarantee for a substantial increase in demand response as important consumers (from a policy perspective) are more likely to insure against such circumstances. From this perspective the market for price insurances (fixed price contracts) is a market for inflexibility.While the analysis above considers the effectiveness of future energy policies to promote demand response, it is also relevant to study the question of how the peak demand problem may develop over time. This question is explicitly addressed in the current report by studying how consumer behavior varies across income levels. The existing literature suggests that electricity consumption is positively related to income, although the income elasticity 2 is fairly small. However, almost all studies concerning income effects have studied aggregate electricity use on monthly or yearly basis. The present study departs from the existing literature by studying how daily household electricity use patterns vary across income levels. This approach is novel since it allows us to analyze how the peak load problem may develop in the future as a result of higher income levels, which is commonly expected.By studying the choice of electricity contracts and by estimating hourly income elasticities, the report approach demand flexibility in an indirect way. In the third analysis of the report we address these issues again, although with a somewhat more direct approach. The choice experiment part in Broberg et al. (2014), which focused on the economic incentives needed in order to change people’s energy consumption in a predefined way, is now deepened. The focus is on how socio-economic factors such as e.g. age, gender, education and income may explain preference heterogeneity among the Swedish population. Energy related factors such as living conditions and heating systems are also considered in the analysis. This analysis will inform us about what types of households are inclined to reschedule their energy use when given relatively small economic incentives, and what household’s that are relatively inflexible and thus require large compensations to change their behavior. We also study preference heterogeneity regarding information dissemination in purpose of anonymous peer comparisons.In the final part of the report we deepen our analysis of households’ demand for information about their own and others electricity use. Besides creating incentives for demand response, new technologies included in the smart grid concept also make it possible for policy makers to use tailored information to help consumers to use energy more efficiently. A number of studies highlight inefficiencies in the households’ use of energy (see e.g. Broberg and Kazukauskas, 2014). One highlighted reality is that people seem to pay little attention to energy issues. Of course, if people pay little attention to the price of electricity, the effectiveness of policy measures that work through the pricechannel is limited. In this part of the report we address four basic questions of great relevance for energy efficiency policies worldwide. The questions are (1) What knowledge do people have about the marginal cost of electricity use in terms of everyday electrical appliances? (2) Are the cost perceptions biased and in what direction? (3) Do inattention to energy issues play a significant role in this bias? (4) Do households want information that may help them de-bias their perceptions about energy costs and use?The report is structured such that section 2 gives a brief background on the issues analyzed in the report. The following sections correspond to the issues outlined in the introduction. Section 7 works to tie the analyses together and conclude our results
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46. |
- Broberg, Thomas, et al.
(author)
-
En elmarknad i förändring : är kundernas flexibilitet till salu eller ens verklig?
- 2014
-
Reports (other academic/artistic)abstract
- I rapporten ”En elmarknad i förändring – Är kundernas flexibilitet till salu eller ens verklig?” tittar en forskargrupp vid Centrum för Miljö- och Naturresursekonomi (CERE) vid Handelshögskolan, Umeå Universitet på konsumenternas nuvarande och framtida roll på elmarknaden. Rapporten är beställd av Energimarknadsinspektionen.
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47. |
- Brocca, Stefania, et al.
(author)
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Mutants provide evidence of the importance of glycosydic chains in the activation of lipase 1 from Candida rugosa
- 2000
-
In: Protein Science. - : Wiley. - 0961-8368 .- 1469-896X. ; 9:5, s. 985-990
-
Journal article (peer-reviewed)abstract
- Sequence analysis of Candida rugosa lipase 1 (LIP1) predicts the presence of three N-linked glycosylation sites at asparagine 291, 314, 351. To investigate the relevance of sugar chains in the activation and stabilization of LIP1, we directed site mutagenesis to replace the above mentioned asparagine with glutamine residues. Comparison of the activity of mutants with that of the wild-type (wt) lipase indicates that both 314 and 351 Asn to Gln substitutions influence, although at a different extent, the enzyme activity both in hydrolysis and esterification reactions, but they do not alter the enzyme water activity profiles in organic solvents or temperature stability. Introduction of Gln to replace Asn35 is likely to disrupt a stabilizing interaction between the sugar chain and residues of the inner side of the lid in the enzyme active conformation. The effect of deglycosylation at position 314 is more difficult to explain and might suggest a more general role of the sugar moiety for the structural stability of lipase 1. Conversely, Asn291Gln substitution does not affect' the lipolytic or the esterase activity of the mutant that behaves essentially as the wt enzyme. This observation supports the hypothesis that changes in activity of Asn314Gln and Asn351Gln mutants are specifically due to deglycosylation.
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48. |
- Brown, Russell D., et al.
(author)
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Tubuloglomerular feedback response in the prenatal and postnatal ovine kidney
- 2011
-
In: American Journal of Physiology - Renal Physiology. - : American Physiological Society. - 0363-6127 .- 1522-1466 .- 1931-857X. ; 300:6, s. F1368-F1374
-
Journal article (peer-reviewed)abstract
- Brown RD, Turner AJ, Carlstrom M, Persson AE, Gibson KJ. Tubuloglomerular feedback response in the prenatal and postnatal ovine kidney. Am J Physiol Renal Physiol 300: F1368-F1374, 2011. First published March 30, 2011; doi:10.1152/ajprenal. 00019.2011.-The tubuloglomerular feedback mechanism (TGF) plays an important role in regulating single-nephron glomerular filtration rate (GFR) by coupling distal tubular flow to arteriolar tone. It is not known whether TGF is active in the developing kidney or whether it can regulate renal vascular tone and thus GFR during intrauterine life. TGF characteristics were examined in late-gestation ovine fetuses and lambs under normovolemic and volume-expanded (VE) conditions. Lambs and pregnant ewes were anesthetized and the fetuses were delivered via a caesarean incision into a heated water bath, with the umbilical cord intact. Under normovolemic conditions, mean arterial pressure of the fetuses was lower than lambs (51 +/- 1 vs. 64 +/- 3 mmHg). The maximum TGF response (Delta P(SFmax)) was found to be lower in fetuses than lambs when tubular perfusion was increased from 0 to 40 nl/min (5.4 +/- 0.7 vs. 10.6 +/- 0.4 mmHg). Furthermore, the flow rate eliciting half-maximal response [turning point (TP)] was 15.7 +/- 0.9 nl/min in fetuses compared with 19.3 +/- 1.0 nl/min in lambs, indicating a greater TGF sensitivity of the prenatal kidney. VE decreased Delta P(SFmax) (4.2 +/- 0.4 mmHg) and increased TP to 23.7 +/- 1.3 nl/min in lambs. In fetuses, VE increased stop-flow pressure from 26.6 +/- 1.5 to 30.3 +/- 0.8 mmHg, and reset TGF sensitivity so that TP increased to 21.3 +/- 0.7 nl/min, but it had no effect on Delta P(SFmax). This study provides direct evidence that the TGF mechanism is active during fetal life and responds to physiological stimuli. Moreover, reductions in TGF sensitivity may contribute to the increase in GFR at birth.
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49. |
- Brunström, Mattias, et al.
(author)
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From efficacy in trials to effectiveness in clinical practice : The Swedish Stroke Prevention Study
- 2016
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In: Blood Pressure. - : Informa UK Limited. - 0803-7051 .- 1651-1999. ; 25:4, s. 206-211
-
Journal article (peer-reviewed)abstract
- Blood pressure treatment has shown great efficacy in reducing cardiovascular events in randomized controlled trials. If this is effective in reducing cardiovascular disease in the general population, is less studied. Between 2001 and 2009 we performed an intervention to improve blood pressure control in the county of Vasterbotten, using Sodermanland County as a control. The intervention was directed towards primary care physicians and included lectures on blood pressure treatment, a computerized decision support system with treatment recommendations, and yearly feed back on hypertension control. Each county had approximately 255000 inhabitants. Differences in age and incidence of cardiovascular disease were small. During follow-up, more than 400000 patients had their blood pressure recorded. The mean number of measurements was eight per patient, yielding a total of 3.4 million blood pressure recordings. The effect of the intervention will be estimated combining the blood pressure data collected from the electronic medical records, with data on stroke, myocardial infarction and mortality from Swedish health registers. Additional variables, from health registers and Statistics Sweden, will be collected to address for confounders. The blood pressure data collected within this study will be an important asset for future epidemiological studies within the field of hypertension.
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50. |
- Burza, Matthias, et al.
(author)
-
Hollow microspheres as targets for staged laser-driven proton acceleration
- 2011
-
In: New Journal of Physics. - : Institute of Physics Publishing (IOPP). - 1367-2630. ; 13, s. 013030-
-
Journal article (peer-reviewed)abstract
- A coated hollow core microsphere is introduced as a novel targetin ultra-intense laser–matter interaction experiments. In particular, it facilitates staged laser-driven proton acceleration by combining conventional target normal sheath acceleration (TNSA), power recycling of hot laterally spreading electrons and staging in a very simple and cheap target geometry. During TNSA of protons from one area of the sphere surface, laterally spreading hot electrons form a charge wave. Due to the spherical geometry, this wave refocuses on the opposite side of the sphere, where an opening has been laser micromachined.This leads to a strong transient charge separation field being set up there, which can post-accelerate those TNSA protons passing through the hole at the right time. Experimentally, the feasibility of using such targets is demonstrated. A redistribution is encountered in the experimental proton energy spectra, as predicted by particle-in-cell simulations and attributed to transient fields set up by oscillating currents on the sphere surface.
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