| 1. |
- Engström, Gunnar, et al.
(författare)
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Pulmonary function and atherosclerosis in the general population : causal associations and clinical implications
- 2024
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Ingår i: European Journal of Epidemiology. - : Springer Nature. - 0393-2990 .- 1573-7284. ; 39:1, s. 35-49
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Tidskriftsartikel (refereegranskat)abstract
- Reduced lung function is associated with cardiovascular mortality, but the relationships with atherosclerosis are unclear. The population-based Swedish CArdioPulmonary BioImage study measured lung function, emphysema, coronary CT angiography, coronary calcium, carotid plaques and ankle-brachial index in 29,593 men and women aged 50–64 years. The results were confirmed using 2-sample Mendelian randomization. Lower lung function and emphysema were associated with more atherosclerosis, but these relationships were attenuated after adjustment for cardiovascular risk factors. Lung function was not associated with coronary atherosclerosis in 14,524 never-smokers. No potentially causal effect of lung function on atherosclerosis, or vice versa, was found in the 2-sample Mendelian randomization analysis. Here we show that reduced lung function and atherosclerosis are correlated in the population, but probably not causally related. Assessing lung function in addition to conventional cardiovascular risk factors to gauge risk of subclinical atherosclerosis is probably not meaningful, but low lung function found by chance should alert for atherosclerosis.
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| 2. |
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| 3. |
- Larsson, Kjell
(författare)
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Tätare uppdateringar behövs av riktlinjer vid astma och KOL
- 2020
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Ingår i: Läkartidningen. - 0023-7205 .- 1652-7518. ; 117
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Rekommendationer för omhändertagande vid astma och kroniskt obstruktiv lungsjukdom (KOL) uppdateras av Läkemedelsverket cirka vart sjunde år och ligger till grund för diagnostik och behandling framför allt i primärvården. Internationella riktlinjer för omhändertagande av astma (Global initiative for asthma, GINA) och KOL (Global initiative for chronic obstructive lung disease, GOLD) uppdateras årligen för att ny kunskap om behandling snabbt ska nå patienterna.De långa intervallen mellan uppdateringarna innebär att rekommendationerna hinner bli inaktuella innan nästa version publiceras, och Sverige hamnar i otakt med internationella riktlinjer. Farmakologisk behandling uppdateras av regionala läkemedelskommittéer, men rekommendationerna skiljer sig i olika delar av landet och stäms ofta inte av mot internationella riktlinjer, vilket leder till ojämlik behandling över landet. Läkemedelsverkets kunskapsstöd Läkemedelsboken innehöll ett kapitel om astma och KOL där man vid behov kunde uppdatera riktlinjer för primärvården, men detta stöd har lagts ned.Vid astma rekommenderar riktlinjerna kortverkande beta-2-agonister vid behov som enda behandling vid lindrig astma (steg 1) samt som tillägg till underhållsbehandling vid svårare sjukdom vid symtomgenombrott [1]. Som alternativ vid svårare astma (steg 3–5) rekommenderas inhalationssteroider i fast kombination med formoterol (steroid + formoterol) vid behov i stället för kortverkande b2-agonister [1]. Vid lindrig astma ger steroid + formoterol vid behov som enda behandling bättre resultat än endast kortverkande beta-2-agonister vid behov [2-5]. Vidare har steroid + formoterol (inhalerat vid behov) lika god exacerbationsförebyggande effekt som regelbunden behandling med inhalationssteroider och kortverkande beta-2-agonister vid behov trots en betydligt lägre kortisonbelastning [3, 5].I juni 2019 uppdaterades GINA:s astmarekommendationer genomgripande [6]. Här rekommenderas steroid + formoterol vid behov vid alla svårighetsgrader av astma. Kortverkande beta-2-agonister (salbutamol, terbutalin) vid behov är struket som förstahandsalternativ. Data indikerar att endast kortverkande beta-2-agonister vid behov faktiskt ökar risken för svåra exacerbationer och astmarelaterad mortalitet. Genom tillägg av inhalationssteroid till en snabb- och långverkande beta-2-agonist reduceras risken signifikant [6]. Vidare rekommenderas steroid + formoterol vid behov som alternativ till regelbunden behandling med inhalationssteroider på steg 2. Riktlinjerna har redan godkänts i flera länder.Vid KOL-behandling är två viktiga mål att lindra symtom och förebygga exacerbationer. Basbehandlingen för att uppnå detta är långverkande antikolinergika. Tillägg av långverkande beta-2-agonist till långverkande antikolinergika ger ytterligare god effekt på symtom, men en mer blygsam tilläggseffekt på exacerbationer [8]. Vid KOL ges inhalationssteroid i syfte att förebygga exacerbation. Hög nivå av eosinofiler i blod förekommer ofta vid KOL. Nyare forskning visar att blodeosinofili varierar hos patienter med KOL. Inhalationssteroider förebygger exacerbationer mer effektivt hos KOL-patienter med eosinofili, och blodeosinofili kan vägleda den förebyggande behandlingen [9-12]. Kontroll av eosinofiler i blod förespråkas i det senaste GOLD-dokumentet inför val av terapi och nydiagnostiserad KOL. Vid KOL och samtidig eosinofili anges inhalationssteroid + långverkande beta-2-agonist som tänkbart förstahandsalternativ i förebyggande syfte [13].Vi anser att behandling av patienter med astma och/eller KOL i Sverige ska baseras på rekommendationer från Läkemedelverket och att de senaste landvinningarna inom området måste återfinnas i riktlinjerna. Läkemedelsverket bör uppdatera riktlinjerna kontinuerligt, helst årligen. Detta kan göras av en mindre grupp experter genom en begränsad arbetsinsats till låg kostnad. Potentiella bindningar eller jävsförhållanden: Samtliga författare har deltagit i expertgrupp och/eller föreläst/haft utbildningsuppdrag hos företag som verkar inom området.
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| 4. |
- Persson, Mats, et al.
(författare)
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2014 års Ekonomipris till Jean Tirole
- 2014
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Ingår i: Ekonomisk Debatt. - Stockholm : Nationalekonomiska föreningen. - 0345-2646. ; :8, s. 5-14
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 5. |
- Persson, Magnus, et al.
(författare)
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Tendenser och trender i tidskriften Vattens artiklar under 75 år
- 2019
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Ingår i: Vatten: tidskrift för vattenvård /Journal of Water Management and research. - 0042-2886. ; 75:1, s. 7-22
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The Journal of Water Management and Research (Vatten) celebrates 2019 its 75th anniversary with a special issue, republishing one article per decade from 1940 to 2010. In the present article, we summarize the development of Swedish water research and management based upon the material published in the journal. We read all issues of the journal, noting important trends, percentage of female authors etc. In total, 2015 articles have been published over 20,600 pages, written by 3,309 authors. During the first decades of the journal history, articles mainly dealt with pollution issues, manifested in, e.g., poor bathing water quality. During the 1950s and 1960s many papers described the expanding municipal waste water treatment with international outlooks, getting inspiration mainly from Germany. Acidification was a hot topic during the 70s and 80s. At the same time articles concerning storm water started to show up and subsequently increased in frequency. During the 90s and 00s wetlands gained popularity, which decreased again in the 10s. The first article on climate change was published already in 1987, but this topic did not become frequent until the 10s.
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| 6. |
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| 7. |
- Ahlström, Gerd, et al.
(författare)
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Similarities and differences between China and Sweden regarding the core features of palliative care for people aged 60 or older : a systematic scoping review
- 2022
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Ingår i: BMC Palliative Care. - : Springer Science and Business Media LLC. - 1472-684X. ; 21
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Despite the increasing longevity of the world's population, with an unprecedented rise in the number of people who need palliative care (PC), there has been sparse research regarding palliative care for older people, especially when it comes to comparison of PC between healthcare systems and cultures. The aim of this systematic scoping review was to identify the characteristics of the body of literature and to examine the knowledge gaps concerning PC research for older people (> 60 years) in two healthcare systems and cultures, mainland China and Sweden.METHODS: The guidelines PRISMA (Preferred Reporting Items for Systematic Reviews), and PICOS (Patient/population, Intervention, Comparison/control, and Outcome) were used. Empirical studies on patients 60 years or older, next of kin or staff participating in a palliative care intervention or setting were included. They were conducted in mainland China or in Sweden during 2007-2019, were published in English and were extracted from seven databases: Embase, PubMed, Scopus, Cinahl, PsycInfo, Academic Search Complete and Cochrane Library. Two independent researchers conducted the selection of studies, data extraction and methodological evaluation. Any disagreements were resolved in consultation with a third researcher. The analysis was manifest directed content analysis based on PICOS domains.RESULTS: Of the 15 studies, four were from mainland China and 11 from Sweden. Both countries included older patients with cancer but also other end-stage diseases such as heart failure and dementia. The studies differed in design, method and the content of the interventions. The study in China based on traditional Chinese medicine concerns traditional Chinese folk music. The six qualitative studies from Sweden were evaluations of five interventions.CONCLUSIONS: Despite the high age of the participating patients, there was no focus on an ageing perspective concerning palliative care. To adapt to the changes taking place in most societies, future research should have increased focus on older persons' need for palliative care and should take account of issues concerning research ethics, ethnicity and culture.REGISTERED IN PROSPERO: CRD42020078685 , available from.
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| 8. |
- Alijagic, Andi, 1992-, et al.
(författare)
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Particle Safety Assessment in Additive Manufacturing : From Exposure Risks to Advanced Toxicology Testing.
- 2022
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Ingår i: Frontiers in Toxicology. - : Frontiers Media S.A.. - 2673-3080. ; 4
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Forskningsöversikt (refereegranskat)abstract
- Additive manufacturing (AM) or industrial three-dimensional (3D) printing drives a new spectrum of design and production possibilities; pushing the boundaries both in the application by production of sophisticated products as well as the development of next-generation materials. AM technologies apply a diversity of feedstocks, including plastic, metallic, and ceramic particle powders with distinct size, shape, and surface chemistry. In addition, powders are often reused, which may change the particles' physicochemical properties and by that alter their toxic potential. The AM production technology commonly relies on a laser or electron beam to selectively melt or sinter particle powders. Large energy input on feedstock powders generates several byproducts, including varying amounts of virgin microparticles, nanoparticles, spatter, and volatile chemicals that are emitted in the working environment; throughout the production and processing phases. The micro and nanoscale size may enable particles to interact with and to cross biological barriers, which could, in turn, give rise to unexpected adverse outcomes, including inflammation, oxidative stress, activation of signaling pathways, genotoxicity, and carcinogenicity. Another important aspect of AM-associated risks is emission/leakage of mono- and oligomers due to polymer breakdown and high temperature transformation of chemicals from polymeric particles, both during production, use, and in vivo, including in target cells. These chemicals are potential inducers of direct toxicity, genotoxicity, and endocrine disruption. Nevertheless, understanding whether AM particle powders and their byproducts may exert adverse effects in humans is largely lacking and urges comprehensive safety assessment across the entire AM lifecycle-spanning from virgin and reused to airborne particles. Therefore, this review will detail: 1) brief overview of the AM feedstock powders, impact of reuse on particle physicochemical properties, main exposure pathways and protective measures in AM industry, 2) role of particle biological identity and key toxicological endpoints in the particle safety assessment, and 3) next-generation toxicology approaches in nanosafety for safety assessment in AM. Altogether, the proposed testing approach will enable a deeper understanding of existing and emerging particle and chemical safety challenges and provide a strategy for the development of cutting-edge methodologies for hazard identification and risk assessment in the AM industry.
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| 9. |
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| 10. |
- Bengtsson, Lars, et al.
(författare)
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Hydrology of transport systems
- 2017
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Ingår i: Handbook of Applied Hydrology, Second Edition. - 9780071835091
-
Bokkapitel (refereegranskat)
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| 11. |
- Bergström, Göran, 1964, et al.
(författare)
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Prevalence of Subclinical Coronary Artery Atherosclerosis in the General Population
- 2021
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Ingår i: Circulation. - Philadelphia : American Heart Association. - 0009-7322 .- 1524-4539. ; 144:12, s. 916-929
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Tidskriftsartikel (refereegranskat)abstract
- Background: Early detection of coronary atherosclerosis using coronary computed tomography angiography (CCTA), in addition to coronary artery calcification (CAC) scoring, may help inform prevention strategies. We used CCTA to determine the prevalence, severity, and characteristics of coronary atherosclerosis and its association with CAC scores in a general population.Methods: We recruited 30 154 randomly invited individuals age 50 to 64 years to SCAPIS (the Swedish Cardiopulmonary Bioimage Study). The study includes individuals without known coronary heart disease (ie, no previous myocardial infarctions or cardiac procedures) and with high-quality results from CCTA and CAC imaging performed using dedicated dual-source CT scanners. Noncontrast images were scored for CAC. CCTA images were visually read and scored for coronary atherosclerosis per segment (defined as no atherosclerosis, 1% to 49% stenosis, or ≥50% stenosis). External validity of prevalence estimates was evaluated using inverse probability for participation weighting and Swedish register data.Results: In total, 25 182 individuals without known coronary heart disease were included (50.6% women). Any CCTA-detected atherosclerosis was found in 42.1%; any significant stenosis (≥50%) in 5.2%; left main, proximal left anterior descending artery, or 3-vessel disease in 1.9%; and any noncalcified plaques in 8.3% of this population. Onset of atherosclerosis was delayed on average by 10 years in women. Atherosclerosis was more prevalent in older individuals and predominantly found in the proximal left anterior descending artery. Prevalence of CCTA-detected atherosclerosis increased with increasing CAC scores. Among those with a CAC score >400, all had atherosclerosis and 45.7% had significant stenosis. In those with 0 CAC, 5.5% had atherosclerosis and 0.4% had significant stenosis. In participants with 0 CAC and intermediate 10-year risk of atherosclerotic cardiovascular disease according to the pooled cohort equation, 9.2% had CCTA-verified atherosclerosis. Prevalence estimates had excellent external validity and changed marginally when adjusted to the age-matched Swedish background population.Conclusions: Using CCTA in a large, random sample of the general population without established disease, we showed that silent coronary atherosclerosis is common in this population. High CAC scores convey a significant probability of substantial stenosis, and 0 CAC does not exclude atherosclerosis, particularly in those at higher baseline risk.
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| 12. |
- Bergström, Göran, et al.
(författare)
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Prevalence of Subclinical Coronary Artery Atherosclerosis in the General Population
- 2021
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Ingår i: Circulation. - : Wolters Kluwer. - 0009-7322 .- 1524-4539. ; 144:12, s. 916-929
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Tidskriftsartikel (refereegranskat)abstract
- Background: Early detection of coronary atherosclerosis using coronary computed tomography angiography (CCTA), in addition to coronary artery calcification (CAC) scoring, may help inform prevention strategies. We used CCTA to determine the prevalence, severity, and characteristics of coronary atherosclerosis and its association with CAC scores in a general population.Methods: We recruited 30 154 randomly invited individuals age 50 to 64 years to SCAPIS (the Swedish Cardiopulmonary Bioimage Study). The study includes individuals without known coronary heart disease (ie, no previous myocardial infarctions or cardiac procedures) and with high-quality results from CCTA and CAC imaging performed using dedicated dual-source CT scanners. Noncontrast images were scored for CAC. CCTA images were visually read and scored for coronary atherosclerosis per segment (defined as no atherosclerosis, 1% to 49% stenosis, or ≥50% stenosis). External validity of prevalence estimates was evaluated using inverse probability for participation weighting and Swedish register data.Results: In total, 25 182 individuals without known coronary heart disease were included (50.6% women). Any CCTA-detected atherosclerosis was found in 42.1%; any significant stenosis (≥50%) in 5.2%; left main, proximal left anterior descending artery, or 3-vessel disease in 1.9%; and any noncalcified plaques in 8.3% of this population. Onset of atherosclerosis was delayed on average by 10 years in women. Atherosclerosis was more prevalent in older individuals and predominantly found in the proximal left anterior descending artery. Prevalence of CCTA-detected atherosclerosis increased with increasing CAC scores. Among those with a CAC score >400, all had atherosclerosis and 45.7% had significant stenosis. In those with 0 CAC, 5.5% had atherosclerosis and 0.4% had significant stenosis. In participants with 0 CAC and intermediate 10-year risk of atherosclerotic cardiovascular disease according to the pooled cohort equation, 9.2% had CCTA-verified atherosclerosis. Prevalence estimates had excellent external validity and changed marginally when adjusted to the age-matched Swedish background population.Conclusions: Using CCTA in a large, random sample of the general population without established disease, we showed that silent coronary atherosclerosis is common in this population. High CAC scores convey a significant probability of substantial stenosis, and 0 CAC does not exclude atherosclerosis, particularly in those at higher baseline risk.
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| 13. |
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| 14. |
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| 15. |
- Ekström, Magnus Pär, et al.
(författare)
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The association of body mass index, weight gain and central obesity with activity-related breathlessness : the Swedish Cardiopulmonary Bioimage Study
- 2019
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Ingår i: Thorax. - : BMJ Publishing Group Ltd. - 0040-6376 .- 1468-3296. ; 74:10, s. 958-964
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Breathlessness is common in the population, especially in women and associated with adverse health outcomes. Obesity (body mass index (BMI) >30 kg/m(2)) is rapidly increasing globally and its impact on breathlessness is unclear.Methods: This population-based study aimed primarily to evaluate the association of current BMI and self-reported change in BMI since age 20 with breathlessness (modified Research Council score >= 1) in the middle-aged population. Secondary aims were to evaluate factors that contribute to breathlessness in obesity, including the interaction with spirometric lung volume and sex.Results: We included 13 437 individuals; mean age 57.5 years; 52.5% women; mean BMI 26.8 (SD 4.3); mean BMI increase since age 20 was 5.0 kg/m(2); and 1283 (9.6%) reported breathlessness. Obesity was strongly associated with increased breathlessness, OR 3.54 (95% CI, 3.03 to 4.13) independent of age, sex, smoking, airflow obstruction, exercise level and the presence of comorbidities. The association between BMI and breathlessness was modified by lung volume; the increase in breathlessness prevalence with higher BMI was steeper for individuals with lower forced vital capacity (FVC). The higher breathlessness prevalence in obese women than men (27.4% vs 12.5%; p<0.001) was related to their lower FVC. Irrespective of current BMI and confounders, individuals who had increased in BMI since age 20 had more breathlessness.Conclusion: Breathlessness is independently associated with obesity and with weight gain in adult life, and the association is stronger for individuals with lower lung volumes.
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| 16. |
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| 17. |
- Ilyas, Aamir, et al.
(författare)
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Residual organic matter and microbial respiration in bottom ash: Effects on metal leaching and eco-toxicity.
- 2015
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Ingår i: Waste Management & Research. - 1096-3669. ; 33:9, s. 805-811
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Tidskriftsartikel (refereegranskat)abstract
- A common assumption regarding the residual organic matter, in bottom ash, is that it does not represent a significant pool of organic carbon and, beyond metal-ion complexation process, it is of little consequence to evolution of ash/leachate chemistry. This article evaluates the effect of residual organic matter and associated microbial respiratory processes on leaching of toxic metals (i.e. arsenic, copper, chromium, molybdenum, nickel, lead, antimony and zinc), eco-toxicity of ash leachates. Microbial respiration was quantified with help of a respirometric test equipment OXITOP control system. The effect of microbial respiration on metal/residual organic matter leaching and eco-toxicity was quantified with the help of batch leaching tests and an eco-toxicity assay - Daphnia magna. In general, the microbial respiration process decreased the leachate pH and eco-toxicity, indicating modification of bioavailability of metal species. Furthermore, the leaching of critical metals, such as copper and chromium, decreased after the respiration in both ash types (fresh and weathered). It was concluded that microbial respiration, if harnessed properly, could enhance the stability of fresh bottom ash and may promote its reuse.
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| 18. |
- Jafari Jam, Reza, et al.
(författare)
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Template-assisted vapour-liquid-solid growth of InP nanowires on (001) InP and Si substrates
- 2020
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Ingår i: Nanoscale. - Cambridge : Royal Society of Chemistry. - 2040-3364 .- 2040-3372. ; 12:2, s. 888-894
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Tidskriftsartikel (refereegranskat)abstract
- We report on the synthesis of vertical InP nanowire arrays on (001) InP and Si substrates using template-assisted vapour-liquid-solid growth. A thick silicon oxide layer was first deposited on the substrates. The samples were then patterned by electron beam lithography and deep dry etching through the oxide layer down to the substrate surface. Gold seed particles were subsequently deposited in the holes of the pattern by the use of pulse electrodeposition. The subsequent growth of nanowires by the vapour-liquid-solid method was guided towards the [001] direction by the patterned oxide template, and displayed a high growth yield with respect to the array of holes in the template. In order to confirm the versatility and robustness of the process, we have also demonstrated guided growth of InP nanowire p-n junctions and InP/InAs/InP nanowire heterostructures on (001) InP substrates. Our results show a promising route to monolithically integrate III-V nanowire heterostructure devices with commercially viable (001) silicon platforms.
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| 19. |
- Johansson, Karl-Axel, et al.
(författare)
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The quality assurance process for the ARTSCAN head and neck study - a practical interactive approach for QA in 3DCRT and IMRT.
- 2008
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Ingår i: Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology. - : Elsevier BV. - 0167-8140 .- 1879-0887. ; 87:2, s. 290-9
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Tidskriftsartikel (refereegranskat)abstract
- AIM: This paper describes the quality assurance (QA) work performed in the Swedish multicenter ARTSCAN (Accelerated RadioTherapy of Squamous cell CArcinomas in the head and Neck) trial to guarantee high quality in a multicenter study which involved modern radiotherapy such as 3DCRT or IMRT. MATERIALS AND METHODS: The study was closed in June 2006 with 750 randomised patients. Radiation therapy-related data for every patient were sent by each participating centre to the QA office where all trial data were reviewed, analysed and stored. In case of any deviation from the protocol, an interactive process was started between the QA office and the local responsible clinician and/or physicist to increase the compliance to the protocol for future randomised patients. Meetings and workshops were held on a regular basis for discussions on various trial-related issues and for the QA office to report on updated results. RESULTS AND DISCUSSION: This review covers the 734 patients out of a total of 750 who had entered the study. Deviations early in the study were corrected so that the overall compliance to the protocol was very high. There were only negligible variations in doses and dose distributions to target volumes for each specific site and stage. The quality of the treatments was high. Furthermore, an extensive database of treatment parameters was accumulated for future dose-volume vs. endpoint evaluations. CONCLUSIONS: This comprehensive QA programme increased the probability to draw firm conclusions from our study and may serve as a concept for QA work in future radiotherapy trials where comparatively small effects are searched for in a heterogeneous tumour population.
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| 20. |
- Malm, Joakim, et al.
(författare)
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UTVÄRDERING AV SI-VERKSAMHETEN VID LUNDS UNIVERSITET 2016/17
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Samverkansinlärning/Supplemental Instruction (SI) är en pedagogisk metod som syftar till att öka genomströmningen i svåra kurser. Metoden uppstod i USA vid University of Missouri Kansas City i mitten på 1970-talet och har därefter spridits till mer än 1500 högre lärosäten i ett trettiotal länder (Martin, 2008). Kort kan SI sägas vara ett studentdrivet komplement till ordinarie undervisning vid högre utbildning. Material i en kurs bearbetas tillsammans i en studiegrupp genom diskussion och grupparbeten under ledning av en äldre student – den s.k. SI-ledaren. Samverkansinlärning kom till Lunds universitet 1994 och har fått stor spridning på universitetet. Lund universitet utgör också ett nav för SI både i Sverige (SI finns på ca 15 svenska högre lärosäten) och i Europa och är också platsen för det nordeuropeiska SI-centret som ansvarar för utbildning och uppföljning i området på uppdrag av det internationella SI-centret i USA. Denna rapport sammanfattar resultaten från en utvärdering av SI-verksamheten vid Lunds universitet under läsåret 2016/17. SI-programmet vid Lunds universitet är omfattande med verksamhet på sex av universitetets fakulteter. Totalt har vi årligen ca 230 verksamma SIledare i ett sjuttiotal kurser. Organisationen av SI varierar mellan de olika fakulteterna. En ytterlighet finns vid LTH och naturvetenskaplig fakultet där verksamheten är starkt centraliserad. Den andra ytterligheten är vid samhällsvetenskaplig fakultet där SI-verksamheten är decentraliserad till de olika ämnena. Det som förenar de olika verksamhetsansvariga är den entusiasm som finns för SI-konceptet samt de dedikerade studenter som är SI-ledare. Närvaron på SI-möten är relativt god. Totalt har vi över 4000 studenter vid Lunds universitet som nyttjar SI varje år och en närvaro kring 30 % av kursregistrerade i snitt. Antalet deltagare på ett SI-möte ligger kring 10 i medeltal med en standardavvikelse kring 5 studenter, vilket ger goda förutsättningar för produktiva SI-möten generellt sett. De utvärderingar som gjorts av sambandet mellan SI-närvaro och kursresultat antyder att aktivt deltagande på SI ökar chanserna till ett bra resultat på kursen oavsett ämne. En specialundersökning i en kurs i matematik antyder också att alla studenter verkar gynnas av att gå på SI oavsett förkunskapsnivå. Enkätutvärderingar bland deltagarna antyder att den främsta drivkraften att delta på SI är att förstå kursmaterialet oavsett ämne och fakultet. Strategiska motiv som att klara kursen är normalt underordnade även om detta varierar beroende på fakultet/ämne. Det är roligt att konstatera att studiesocial interaktion mestadels värderas högt som motiv att delta på SI. Arbetsmiljön på SI upplevs som bra (lätt att fråga, lättsam, positiv och stödjande atmosfär samt lagom tempo) och generellt verkar mötena följa SI-metodiken väl. Oavsett fakultet verkar majoriteten av deltagarna känna att SI-mötena hjälper dem i deras kursarbete. De får en bättre förståelse av vad som förväntas av dem i kursen, ett ökat intresse för ämnet samt stöd i kursarbetet. De allra flesta verkar känna att de får en betydligt djupare förståelse för det kursmaterial man går igenom på SI-mötena. Dessutom upplever många att de sannolikt kommer att förbättra sitt kursresultat genom deltagande på SI. Detta antagande stödjs också som nämnts ovan av SI-närvaro och examinationsstatistik från kurser och ju högre SI närvaro desto bättre verkar det gå oavsett ämnesområde. Att döma av deltagarnas enkätsvar är det inte bara kursen med tillhörande SI som gynnas av SI-deltagande. Flera generella färdigheter tränas som bör gynna studenter i studier i andra kurser utan SI. Många deltagare upplever att färdigheter som problemlösningsförmåga, kritiskt tänkande, lagsamverkan och samarbete, presentation inför andra och sätt att studera utvecklats genom att delta på SI. Dessutom får flera ett förbättrat självförtroende i sina studier samt ett ökat nätverk av studiekamrater. Tidigare studier vid LTH antyder att de som deltagit på SI också presterar bättre i andra kurser utan SI och att de är mindre benägna att göra studieavbrott och tar ut examen i högre utsträckning (Malm, Bryngfors, & Mörner, 2012; Malm, Bryngfors, & Mörner, 2015; Malm, Bryngfors, & Fredriksson, 2017). Deltagarnas svar på frågan med ”Vad tycker du är det bästa med SI-mötena?” betonar möjligheten till diskussion och social interaktion, en god studiemiljö samt förståelseinriktad studietid. Detta gäller oavsett ämnesområde. Vad kan då förbättras med SI-mötena? Några antyder att strukturen/effektiviteten på mötena kan vara bristande. Detta kan i sin tur bero av att stödet för SI-ledare i form av observationer och handledning inte alltid fungerar som det skall. Detta är något att titta närmare på inom universitetet. Annat som kan förbättras med SI-verksamheten är att man vill ha fler möten, mer tid till mötena eller bättre schematider. Internationellt anses det ofta att SI-ledarna är de största ”vinnarna” i SI-konceptet pga de ledarskaps- och grupphanteringsfärdigheter de erhåller. Detta antyds även i enkätutvärderingarna för SI-ledare vid Lunds universitet. SI-ledarna verkar dessutom få ett bättre självförtroende, djupare förståelse av kursämnet samt bli bättre på att prata inför andra. Både deltagare och SI-ledare är generellt nöjda med sina möten.
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| 21. |
- Malmberg Persson, Kärstin, et al.
(författare)
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När iskanten tog paus i Vimmerby
- 2008
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Ingår i: Geologiskt forum. ; 15:60, s. 12-15
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Tidskriftsartikel (populärvet., debatt m.m.)
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| 22. |
- Moberg, Christina, et al.
(författare)
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De unga gör helt rätt när de stämmer staten
- 2022
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Ingår i: Aftonbladet. - 1103-9000.
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- 1 620 forskare och lärare i forskarvärlden: Vi ställer oss bakom Auroras klimatkrav
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| 23. |
- Naseri-Rad, Mehran, et al.
(författare)
-
Inside-t : A groundwater contamination transport model for sustainability assessment in remediation practice
- 2021
-
Ingår i: Sustainability (Switzerland). - : MDPI AG. - 2071-1050. ; 13:14
-
Tidskriftsartikel (refereegranskat)abstract
- Current sustainability assessment (SA) tools to help deal with contaminated groundwater sites are inherently subjective and hardly applied. One reason may be lack of proper tools for addressing contaminant spread which are basically objective. To fill this gap, there is a need for contaminant transport models that provide site managers with needed room for applying their judgments and considerations about the efficiency of each remediation method based on their experiences in similar cases. INSIDE-T uses trend analysis and inverse modeling to estimate transport parameters. It then simulates contaminant transport both with and without the inclusion of remedial actions in a transparent way. The sustainability of each remedy measure can then be quantified based on the underlying SA tool (INSIDE). INSIDE-T was applied to a site in south Sweden, contaminated with pentachlorophenol. Simulation scenarios were developed to enable comparison between various remediation strategies and combinations of these. The application indicated that natural attenuation was not a viable option within the timeframe of interest. Although pump-and-treat combined with a permeable reactive barrier was found to be just as effective as bioremediation after five years, it received a much lower sustainability score overall. INSIDE-T outcomes enable site managers to test and evaluate different scenarios, a necessity in participatory decision-making practices such as remediation projects.
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| 24. |
- Nilsson, Anna, et al.
(författare)
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Frequent detection of respiratory agents by multiplex PCR on oropharyngeal samples in Swedish school-attending adolescents
- 2012
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Ingår i: Scandinavian Journal of Infectious Diseases. - : Informa UK Limited. - 0036-5548 .- 1651-1980. ; 44, s. 393-397
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Tidskriftsartikel (refereegranskat)abstract
- Background: Respiratory agents may be detected in the oropharynx of healthy individuals. The extent of this condition and the reasons behind it are largely unknown. The objective of this study was to determine the factors associated with the presence of respiratory agents in the oropharynx of adolescents healthy enough to attend school activities. Methods: On a single day in December, samples from the posterior wall of the oropharynx of adolescents aged 1015 y were obtained using cotton-tipped swabs. The samples were analyzed by real-time polymerase chain reaction (PCR) for the presence of 13 respiratory viruses and 2 bacteria (Mycoplasma pneumoniae and Chlamydophila pneumoniae). Results: Out of the 232 adolescents sampled, 67 (29%) had any respiratory symptom. A positive PCR result was found in 50 individuals (22%). Human rhinovirus was the most commonly found agent. Respiratory agents were significantly more frequent in the younger age group (1013 y) than in the older age group (1415 y): 26% (38/148) vs 14% (12/84), respectively; p = 0.04. Cough was the only symptom that was more common among individuals with a positive PCR test than among those with a negative PCR test: 8/50 (16%) vs 11/182 (6%); p = 0.02. Family size and class size were not associated with the likelihood of a positive PCR test. Conclusions: The presence of respiratory agents in the oropharynx is a frequent finding among adolescents healthy enough to attend school activities. The high prevalence was found to be associated with young age, but not with the size of the family or class. © 2012 Informa Healthcare.
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| 25. |
- Persson, Anton E.O., et al.
(författare)
-
Reduced annealing temperature for ferroelectric HZO on InAs with enhanced polarization
- 2020
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 116:6
-
Tidskriftsartikel (refereegranskat)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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| 26. |
- Persson, Ingmar, et al.
(författare)
-
An EXAFS Spectroscopic, Large Angle X-Ray Scattering and Crystallo¬graphic Study of the Hexahydrated and the Dimethyl Sulfoxide and Pyridine-1-Oxide Hexasolvated Mercury(II) Ions
- 2008
-
Ingår i: Chemistry, A European Journal. ; 14, s. 6687-6696
-
Tidskriftsartikel (populärvet., debatt m.m.)abstract
- The structure of the solvated mercury(II) ion in aqueous and dimethyl sulfoxide solution has been studied by means of large angle X-ray scattering (LAXS) and EXAFS tech¬niques. The distribution of the Hg-O bond distances is unusually wide and asymmetric in both solvents. In aqueous solution hexahydrated [Hg(OH2)6]2+ ions in distorted octahedral configuration, with the centroid of the Hg-O bond distances at 2.38(1) Å, are surrounded by a diffuse second hydration sphere, with HgOII distances around a mean value of 4.20(2) Å. In dimethyl sulfoxide solution the six Hg-O and HgS distances of the hexasolvated Hg(OS(CH3)2)6]2+ complex are centered around 2.38(1) and 3.45(2) Å, respectively. The crystal structure of hexakis¬(pyridine-1-oxide)mercury(II) perchlorate has been re-determi¬ned at 100 K. The space group R implies six equal Hg-O bond distances of 2.3416(7) Å for the Hg(ONC5H5)62+ complex, as also for the hexaaquamercury(II) perchlorate and hexakis(dimethyl sulfoxide)mercury(II) trifluoro¬methanesulfonate compounds, according to previous crystallographic results. However, EXAFS results for those compounds in all cases reveal strongly asymmetric Hg-O bond distance distributions. Vibronic coupling of close valence states in a so-called Pseudo Jahn-Teller Effect probably induces the distorted configurations.
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| 27. |
- Persson, Ingmar, et al.
(författare)
-
An EXAFS Spectroscopic, Large-Angle X-Ray Scattering, and Crystallographic Study of Hexahydrated, Dimethyl Sulfoxide and Pyridine 1-Oxide Hexasolvated Mercury(II) Ions
- 2008
-
Ingår i: Chemistry - A European Journal. - : Wiley-VCH Verlagsgesellschaft. - 0947-6539 .- 1521-3765. ; 14:22, s. 6687-6696
-
Tidskriftsartikel (refereegranskat)abstract
- The structure of the solvated mercury(II) ion in water and dimethyl sulfoxide has been studied by means of large‐angle X‐ray scattering (LAXS) and extended X‐ray absorption fine structure (EXAFS) techniques. The distribution of the HgO distances is unusually wide and asymmetric in both solvents. In aqueous solution, hexahydrated [Hg(OH2)6]2+ ions in a distorted octahedral configuration, with the centroid of the HgO distance at 2.38(1) Å, are surrounded by a diffuse second hydration sphere with Hg⋅⋅⋅OII distances of 4.20(2) Å. In dimethyl sulfoxide, the six HgO and Hg⋅⋅⋅S distances of the hexasolvated [Hg{OS(CH3)2}6]2+ complex are centered around 2.38(1) and 3.45(2) Å, respectively. The crystal structure of hexakis(pyridine 1‐oxide)mercury(II) perchlorate has been redetermined. The space group R implies six equal HgO distances of 2.3416(7) Å for the [Hg(ONC5H5)6]2+ complex at 100 K. However, EXAFS studies of this compound, and of the solids hexaaquamercury(II) perchlorate and hexakis(dimethyl sulfoxide)mercury(II) trifluoromethanesulfonate, also with six equidistant HgO bonds according to crystallographic results, reveal in all cases strongly asymmetric HgO distance distributions. Vibronic coupling of valence states in a so‐called pseudo‐Jahn–Teller effect probably induces the distorted configurations.
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| 28. |
- Persson, Jan, 1962, et al.
(författare)
-
Fully covered stents are similar to semi-covered stents with regard to migration in palliative treatment of malignant strictures of the esophagus and gastric cardia : results of a randomized controlled trial.
- 2017
-
Ingår i: Surgical Endoscopy. - : Springer Science and Business Media LLC. - 0930-2794 .- 1432-2218. ; 31:10, s. 4025-4033
-
Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Stent migration is a significant clinical problem in palliation of malignant strictures in the esophagus and gastro-esophageal junction (GEJ). We have compared a newer design of a fully-covered stent to a widely used semi-covered stent using migration >20 mm as the primary outcome variable. Effects on dysphagia, quality of life (QoL) and re-intervention frequency were also investigated.METHODS: Patients with dysphagia due to non-curable esophagus/GEJ cancer were randomized to receive either a more recent design of a fully-covered stent (n = 48) or a conventional semi-covered stent (n = 47). Chest x-ray, dysphagia and QoL were studied at baseline, one week, four weeks and three months thereafter.RESULTS: There were no significant differences either in stent migration distance or in the migration frequency. Stent migration during the total study period occurred in 37.2 % in the semi-covered group compared to 20.0 % for the fully-covered group. Dysphagia was measured with Watson and Ogilvie scores and with the dysphagia module in the QoL scale (QLQ-OG25). On average, there was a tendency to better dysphagia relief for the fully-covered design as scored with the two latter dysphagia instruments (p= 0.081 and p= 0.067) at three months and towards more re-interventions in the semi-covered group (p= 0.083).CONCLUSION: In spite of its somewhat lower intrinsic radial force, the fully-covered stent was comparable to the conventional semi-covered stent with regard to stent migration. The data further suggest a potential benefit of the fully-covered stent in improving dysphagia in patients with longer life expectancy.
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| 29. |
- Persson, Josefine, 1980, et al.
(författare)
-
Stratification of COVID-19 patients based on quantitative immune-related gene expression in whole blood.
- 2022
-
Ingår i: Molecular immunology. - : Elsevier BV. - 1872-9142 .- 0161-5890. ; 145, s. 17-26
-
Tidskriftsartikel (refereegranskat)abstract
- The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes mild symptoms in the majority of infected individuals, yet in some cases it leads to a life-threatening condition. Determination of early predictive biomarkers enabling risk stratification for coronavirus disease 2019 (COVID-19) patients can inform treatment and intervention strategies. Herein, we analyzed whole blood samples obtained from individuals infected with SARS-CoV-2, varying from mild to critical symptoms, approximately one week after symptom onset. In order to identify blood-specific markers of disease severity status, a targeted expression analysis of 143 immune-related genes was carried out by dual-color reverse transcriptase multiplex ligation-dependent probe amplification (dcRT-MLPA). The clinically well-defined subgroups of COVID-19 patients were compared with healthy controls. The transcriptional profile of the critically ill patients clearly separated from that of healthy individuals. Moreover, the number of differentially expressed genes increased by severity of COVID-19. It was also found that critically ill patients can be distinguished by reduced peripheral blood expression of several genes, which most likely reflects the lower lymphocyte counts. There was a notable predominance of IFN-associated gene expression in all subgroups of COVID-19, which was most profound in critically ill patients. Interestingly, the gene encoding one of the main TNF-receptors, TNFRS1A, had selectively lower expression in mild COVID-19 cases. This report provides added value in understanding COVID-19 disease, and shows potential of determining early immune transcript signatures in the blood of patients with different disease severity. These results can guide further explorations to uncover mechanisms underlying immunity and immunopathology in COVID-19.
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| 30. |
- Persson, Magnus, et al.
(författare)
-
A new non-invasive ultrasonic method for simultaneous measurements of longitudinal and radial arterial wall movements: first in vivo trial.
- 2003
-
Ingår i: Clinical Physiology and Functional Imaging. - 1475-0961. ; 23:5, s. 247-251
-
Tidskriftsartikel (refereegranskat)abstract
- During recent years, the radial movement of the arterial wall has been extensively studied, and measurements of the radial movement are now an important tool in cardiovascular research for characterizing the mechanical properties of the arterial wall. In contrast, the longitudinal movement of vessels has gained little or no attention as it has been presumed that this movement is negligible. With modern high-resolution ultrasound, it can, however, be seen that the intima-media complex of the arterial wall moves not only in the radial direction, but also in the longitudinal direction during pulse-wave propagation. This paper describes a new non-invasive ultrasonic method that is able to measure simultaneously two dimensionally arterial vessel wall movements. The method is demonstrated in a limited in vivo trial. Results from the in vivo trial show that, apart from the well-known radial movement, there is a distinct longitudinal movement in the human common carotid artery with, in this case, the intima-media complex moving substantially as compared with the region of the tunica adventitia. Two-dimensional evaluation of the vessel-wall movements, taking not only the radial movement, but also the longitudinal movement into account, may provide novel information of importance in the evaluation of vessel-wall function.
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| 31. |
- Persson, Magnus, et al.
(författare)
-
Non-invasive measurement of arterial longitudinal movement
- 2002
-
Ingår i: Proceedings of the IEEE Ultrasonics Symposium. - 1051-0117. ; 2, s. 1783-1786
-
Konferensbidrag (refereegranskat)abstract
- In arterial vessel wall characterisation the longitudinal movements of vessels have gained little or no attention. It has been presumed that the arterial vessels move very little in the longitudinal direction. With modern high resolution ultrasound it can, however, be seen that arterial vessels move not only in the circumferential, but also in longitudinal direction. This paper describes a non-invasive, ultrasound based method which estimates the longitudinal and the circumferential movement, respectively. The method is demonstrated in a limited in vivo study of the common carotid artery. Results show that, apart from the well known circumferential movement, there is a distinct longitudinal movement.
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| 32. |
- Samuelson, Lars, et al.
(författare)
-
Semiconductor nanowires for 0D and 1D physics and applications
- 2004
-
Ingår i: Physica E: Low-Dimensional Systems and Nanostructures. - : Elsevier BV. - 1386-9477. ; 25:2-3, s. 313-318
-
Tidskriftsartikel (refereegranskat)abstract
- During the last 5 years the potential for applications of semiconductor nanowires has grown rapidly via the development of methods for catalytically induced nanowire growth using the, so-called vapor-liquid-solid (VLS) growth mode. The VLS method offers a high degree of control of parameters such as position, diameter, length and composition, including the realization of atomically abrupt heterostructure interfaces inside a nanowire. In this review, we summarize the progress and the standing of our research from the point of view of controlled growth, structural and electronic properties and in terms of different families of devices which have been possible to realize. (C) 2004 Elsevier B.V. All rights reserved.
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| 33. |
- Stefansson, Petter, et al.
(författare)
-
Synthetic generation of passive infrared motion sensor data using a game engine
- 2021
-
Ingår i: Sensors. - : MDPI. - 1424-8220. ; 21:23
-
Tidskriftsartikel (refereegranskat)abstract
- Quantifying the number of occupants in an indoor space is useful for a wide variety of applications. Attempts have been made at solving the task using passive infrared (PIR) motion sensor data together with supervised learning methods. Collecting a large labeled dataset containing both PIR motion sensor data and ground truth people count is however time-consuming, often requiring one hour of observation for each hour of data gathered. In this paper, a method is proposed for generating such data synthetically. A simulator is developed in the Unity game engine capable of producing synthetic PIR motion sensor data by detecting simulated occupants. The accuracy of the simulator is tested by replicating a real-world meeting room inside the simulator and conducting an experiment where a set of choreographed movements are performed in the simulated environment as well as the real room. In 34 out of 50 tested situations, the output from the simulated PIR sensors is comparable to the output from the real-world PIR sensors. The developed simulator is also used to study how a PIR sensor’s output changes depending on where in a room a motion is carried out. Through this, the relationship between sensor output and spatial position of a motion is discovered to be highly non-linear, which highlights some of the difficulties associated with mapping PIR data to occupancy count.
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| 34. |
- Söderberg, Stefan, et al.
(författare)
-
MEASURES OF WAIST AND HIP MODIFY SEX-SPECIFIC ASSOCIATIONS BETWEEN BODY MASS INDEX AND PREVALENCE OF CORONARY ARTERY CALCIFICATION IN OPPOSITE DIRECTIONS
- 2019
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Ingår i: Journal of the American College of Cardiology. - : ELSEVIER SCIENCE INC. - 0735-1097 .- 1558-3597. ; 73:9, s. 13-13
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Background: Obesity is associated with increased risk of cardiovascular disease. However, there is still a debate whether accumulation of fat in certain depots modifies this risk. Using data from the CArdioPulmonary bioImage Study (SCAPIS), we investigated if anthropometric measurements of obesity (waist and hip) modifies the risk of coronary artery calcification. Methods: In the first 15,810 participants in SCAPIS (mean age 58 years, 52% women), data on coronary artery calcification score (CACS) and anthropometry were recorded and traditional cardiovascular risk factors were measured. Body mass index (BMI) was categorized as; <25, 25-30, 30-35 and >35 kg/m2 , quartiles of waist and hip circumferences were constructed within each BMI category and compared using the lowest quartile as reference. Results were adjusted for site, age, smoking and diabetes status. Results: Obesity (BMI >30 kg/m2 ) was found in 21.9% of men and in 20.5% of women. In both sexes the odds ratio (OR) for CACS >0 increased with increasing BMI categories: comparing <25 and >35 kg/m2 , OR = 2.1 (95% CI: 1.6-2.7) for men and OR = 1.4 (1.2-1.8) for women. In addition, increasing quartiles of waist significantly increased the prevalence of CACS >0 for men [p = 0.05; OR = 1.2 (1.0-1.4) for highest quartile] and women [p = 0.005; OR = 1.3 (1.1-1.5)] while increasing quartiles of hip significantly decreased the prevalence for men [p = 0.005; OR = 0.8 (0.6-0.9)] and women [p = 0.04; OR = 0.8 (0.7-0.9)]. Data on education level and physical activity did not affect the model. Conclusion: Increased BMI is associated with increased prevalence of coronary artery calcification and the distribution of fat modifies this risk. Our results suggest that gluteofemoral adipose tissue (hip) counteracts the negative effects associated with BMI and abdominal adipose tissue (waist).
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| 35. |
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| 36. |
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| 37. |
- van Praagh, Martijn, et al.
(författare)
-
Water and solute movement in air pollution control residues measured by time domain reflectometry.
- 2007
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Ingår i: Journal of Environmental Engineering. - 0733-9372. ; 133:7, s. 750-757
-
Tidskriftsartikel (refereegranskat)abstract
- The mobility of pollutants from air pollution control (APC) residues is strongly influenced by its contact with water. This study aims to verify the applicability of time-domain reflectometry (TDR) to infer water and solute movement in situ in an APC residue–compost mixture in a laboratory column. The calibrated dielectric permittivity–volumetric water content relationship (K−thetav) for the material shows a distinct plateau at midrange volumetric water contents, which are underestimated by Topp's K−thetav model throughout the studied range. The coating of probes enables a clear TDR signal collection and analysis up to electrical conductivity values of 280 mS cm−1. Heterogeneities in packing and channel flow in the column are revealed by TDR measurements. Water contents inferred by TDR signal analysis require careful interpretation when used in materials such as APC residues, due to the high amount of water bound in the hydration shells of ions released into the pore water.
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| 38. |
- Abbasi, Alireza, et al.
(författare)
-
Crystallographic and Vibrational Spectroscopic Studies of Octakis(dimethyl sulfoxide)lanthanoid(III) Iodides
- 2007
-
Ingår i: Inorganic Chemistry. - : American Chemical Society (ACS). - 0020-1669 .- 1520-510X. ; 46:19, s. 7731-7741
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Tidskriftsartikel (refereegranskat)abstract
- The octakis(DMSO) (DMSO = dimethylsulfoxide) neodymium(III), samarium(III), gadolinium(III), dysprosium(III), erbium(III), and lutetium(III) iodides crystallize in the monoclinic space group P21/n (No. 14) with Z = 4, while the octakis(DMSO) iodides of the larger lanthanum(III), cerium(III), and praseodymium(III) ions crystallize in the orthorhombic space group Pbca (No. 61), Z = 8. In all [Ln(OS(Me2)8]I3 compounds the lanthanoid(III) ions coordinate eight DMSO oxygen atoms in a distorted square antiprism. Up to three of the DMSO ligands were found to be disordered and were described by two alternative configurations related by a twist around the metal−oxygen (Ln−O) bond. To resolve the atomic positions and achieve reliable Ln−O bond distances, complete semirigid DMSO molecules with restrained geometry and partial occupancy were refined for the alternative sites. This disorder model was also applied on previously collected data for the monoclinic octakis(DMSO)yttrium(III) iodide. At ambient temperature, the eight Ln−O bond distances are distributed over a range of about 0.1 Å. The average value increases from Ln−O 2.30, 2.34, 2.34, 2.36, 2.38, 2.40 to 2.43 Å (Ln = Lu, Er, Y, Dy, Gd, Sm, and Nd) for the monoclinic [Ln(OSMe2)8]I3 structures, and from 2.44, 2.47 to 2.49 Å (Ln = Pr, Ce, and La) for the orthorhombic structures, respectively. The average of the La−O and Nd−O bond distances remained unchanged at 100 K, 2.49 and 2.43 Å, respectively. Despite longer bond distances and larger Ln−O−S angles, the cell volumes are smaller for the orthorhombic structures (Ln = Pr, Ce, and La) than for the monoclinic structure with Ln = Nd, showing a more efficient packing arrangement. Raman and IR absorption spectra for the [Ln(OS(CH3)2)8]I3 (Ln = La, Ce, Pr, Nd, Gd, Tb, Dy, Er, Lu, and Y) compounds, also deuterated for La and Y, have been recorded and analyzed by means of normal coordinate methods. The force constants for the Ln−O and S−O stretching modes in the complexes increase with decreasing Ln−O bond distance and show increasing polarization of the bonds for the smaller and heavier lanthanoid(III) ions.
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| 39. |
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| 40. |
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| 41. |
- Abbasi, Alireza, et al.
(författare)
-
Highly hydrated cations : Deficiency, mobility and coordination of water in crystalline nonahydrated scandium(III), yttrium(III) and lanthanoid(III) trifluoromethanesulfonate
- 2005
-
Ingår i: Chemistry - A European Journal. - : Wiley. - 0947-6539 .- 1521-3765. ; 11:14, s. 4065-4077
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Tidskriftsartikel (refereegranskat)abstract
- Trivalent lanthanide-like metal ions coordinate nine water oxygen atoms, which form a tricapped trigonal prism in a large number of crystalline hydrates. Water deficiency, randomly distributed over the capping positions, was found for the smallest metal ions in the isomorphous nonahydrated trifluoromethanesulfonates, [M(H2O)(n)]CF3SO3)(3), in which M=Sc-III, Lu-III, Yb-III, Tm-III or Er-III. The hydration number n increases (n=8.0(1), 8.4(1), 8.7(1), 8.8(1) and 8.96(5), respectively) with increasing ionic size. Deuterium (H-2) solid-state NMR spectroscopy revealed fast positional exchange between the coordinated capping and prism water molecules; this exchange started at temperatures higher than about 280 K for lutetium(m) and below 268 K for scandium(m). Similar positional exchange for the fully nonahydrated yttrium(m) and lanthanum(m) compounds started at higher temperatures, over about 330 and 360 K, respectively. An exchange mechanism is proposed that can exchange equatorial and capping water molecules within the restrictions of the crystal lattice, even for fully hydrated lanthanoid(III) ions. Phase transitions occurred for all the water-deficient compounds at; 185 K. The hydrated scandium(III) trifluoromethanesulfonate transforms reversibly (Delta H degrees= -0.80(1) kJ mol(-1) on cooling) to a trigonal unit cell that is almost nine times larger, with the scandium ion surrounded by seven fully occupied and two partly occupied oxygen atom positions in a distorted capped trigonal prism. The hydrogen bonding to the trifluoromethanesulfonate anions stabilises the trigonal prism of water ligands, even for the crowded hydration sphere of the smallest metal ions in the series. Implications for the Lewis acid catalytic activity of the hydrated scandium(III) and lanthanoid(III) trifluoromethanesulfonates for organic syntheses performed in aqueous media are discussed.
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| 42. |
- Abelow, Alexis, et al.
(författare)
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Electroresponsive Nanoporous Membranes by Coating Anodized Alumina with Poly(3,4-ethylenedioxythiophone) and Polypyrrole
- 2014
-
Ingår i: Macromolecular materials and engineering. - : Wiley-VCH Verlagsgesellschaft. - 1438-7492 .- 1439-2054. ; 299:2, s. 190-197
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Tidskriftsartikel (refereegranskat)abstract
- Electrically-active nanoporous membranes are prepared by coating the surface of anodized alumina with electroactive polymers using vapor phase polymerization with four combinations of conjugated polymers and doping ions: poly(3,4-ethylenedioxythiophone) and polypyrrole, FeCl3 and FeTs3. The permeability of the polymer-coated membranes is measured as a function of the applied electric potential. A reversible three-fold increase is found in molecular flux of a neutral dye for membranes in oxidized state compared to that in the reduced state. After analyzing various factors that may affect the molecular transport through these membranes, it is concluded that the observed behavior results mostly from swelling/deswelling of the polymers and from the confinement of the polymers inside the nanopores.
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| 43. |
- Aboulila, Tarek Selim, et al.
(författare)
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Assessment of inter-plant emitter distance and effects of irrigation water salinity on APRDI using Hydrus-2D
- 2011
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Ingår i: European Journal of Scientific Research. - 1450-216X. ; 58, s. 266-277
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Tidskriftsartikel (refereegranskat)abstract
- Abstract in UndeterminedModern irrigation techniques are becoming increasingly important in water-scarce countries. In this study, a two-dimensional water and solute transport model, Hydrus-2D, was used to assess the impact of inter-plant emitter distance (IPED) and irrigation water salinity on soil moisture and salinity distribution as well as on water balance components under alternate partial root-zone surface drip irrigation (APRDI) of tomato growing in loamy sand soil. Three IPED (20, 30, and 40 cm) and three irrigation water salinity levels (0, 1, and 2 dS/m) were used to execute different simulation scenarios. Simulation results indicated that the fluctuations in water content within the root zone were more pronounced in case of 20 cm IPED. The root water uptake increased as the IPED decreased. Using brackish irrigation water in APRDI caused significant augmentation in soil salinity in the top soil layer especially at the location of plant. The impact of irrigation water salinity on root water uptake increased as the IPED increased. As irrigation water salinity increased the root water uptake decreased. At plant location, soil salinity reached its highest values at the top soil layer in case of 30 and 40 cm IPED with brackish irrigation water. However, high soil salinity values were observed between the 40 and 65 cm depths in case of 20 cm IPED. Based on the results, it appears that APRDI with non-saline irrigation water is more effective with short IPED considering that approximately half of the root system was exposed to drying cycle. In addition, short IPED is recommended in APRDI when using brackish irrigation water especially for plants with shallow root system taking into account crop salinity tolerance.
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| 44. |
- Aboulila, Tarek Selim, et al.
(författare)
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Field experiment and numerical simulation of point source irrigation with multiple tracers.
- 2013
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Ingår i: International Journal of Sustainable Water and Environmental Systems. - 1923-7545.
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- In this study, three plots in sandy soil in northern Tunisia were irrigated by a single irrigation dripper with a solution containing dye and bromide for three successive hours. Fifteen hours after ceasing of infiltration, horizontal 5 cm trenches were dug. Dye pattern, bromide concentration, and water content were recorded. Indication of preferential flow due to water repellency of initial dry soil was found during the early stages of infiltration. However no deep preferential flow occurred. This enables the use of drip irrigation to improve the sustainability of irrigation systems. Numerical simulation using Hydrus-2D was conducted for the field experiment. It was found that in both field experiments and numerical simulation the mobility of the bromide is different from the mobility of dye; the dye was retarded approximately twice by volume compared to bromide. The simulation results support the use of Hydrus-2D as a roughly, rapid and labor saving tool for investigation tracers’ mobility in sandy soil under point source irrigation.
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| 45. |
- Aboulila, Tarek Selim, et al.
(författare)
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Influence of geometric design of alternate partial root-zone subsurface drip irrigation (APRSDI) with brackish water on soil moisture and salinity distribution
- 2012
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Ingår i: Agricultural Water Management. - : Elsevier BV. - 1873-2283 .- 0378-3774. ; 103, s. 182-190
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Tidskriftsartikel (refereegranskat)abstract
- In alternate partial root-zone irrigation (APRI) a significant amount of irrigation water can be saved without considerable yield reduction. In this paper, Hydrus-2D/3D was used to investigate the impact of geometric design of alternate partial root-zone subsurface drip irrigation (APRSDI) with brackish water for growing tomato on soil moisture and salinity distribution. Three inter-plant emitter distances (IPED; 20, 30, and 40 cm), two emitter depths (10 and 20 cm), and three irrigation water salinity levels (0, 1, and 2 dS m-1) were used to implement the proposed simulation scenarios in loamy sand soil during a 40-day simulation period. The simulation results showed that higher soil moisture content was found beneath the plant trunk in case of 20 cm (short IPED) and near the domain border in case of 30 and 40 cm IPED. Short IPED guarantees more water in the maximum root density zone. A deeper wetting front occurred for deep emitter depth, while the wetting front reached the soil surface for shallow emitter depth. Salinity results revealed that as irrigation water salinity increased, the salinity in the top soil increased. In addition, the salinity at the soil surface increased as IPED and emitter depth increased. Higher root water uptake rates were recorded in the case of 20 cm IPED while the emitter depth did not show any considerable effect on root water uptake rates. Moreover, the applied irrigation water was fully consumed by the plant in case of short IPED. Emitter depth and salinity of irrigation water had negligible effect on amount of irrigation water extracted by plant roots and percolated amount below the bottom boundary of the flow domain. Overall, short IPED is recommended in APRSDI with or without brackish irrigation water regardless of the emitter depth.
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| 46. |
- Aboulila, Tarek Selim, et al.
(författare)
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Numerical evaluation of subsurface trickle irrigation with brackish water
- 2013
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Ingår i: Irrigation Science. - : Springer Science and Business Media LLC. - 0342-7188 .- 1432-1319. ; 31:5, s. 1125-1137
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Tidskriftsartikel (refereegranskat)abstract
- In this study, an assessment for a proposed irrigation system in the El-Salam Canal cultivated land, Egypt, was conducted. A numerical model (HYDRUS-2D/3D) was applied to investigate the effect of irrigation amount, frequency, and emitter depth on the wetted soil volume, soil salinity levels, and deep percolation under subsurface trickle irrigation (SDI) of tomato growing with brackish irrigation water in three different soil types. The simulations indicated that lower irrigation frequency increased the wetted soil volume without significant increase in water percolate below the plant roots. Deep percolation decreased as the amount of irrigation water and emitter depth decreased. With the same amount of irrigation water, the volume of leached soil was larger at lower irrigation frequency. The salinity of irrigation water under SDI with shallow emitter depth did not show any significant effect on increasing the soil salinity above tomato crop salt tolerance. Based on the results, it appears that the use of SDI with brackish irrigation water is an effective method for growing tomato crop in El-Salam Canal cultivated land especially with shallow emitter depth.
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| 47. |
- Aboulila, Tarek Selim, et al.
(författare)
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Simulation of soil water and salinity distribution under surface drip irrigation
- 2013
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Ingår i: Irrigation and Drainage. - : Wiley. - 1531-0361 .- 1531-0353. ; 62:3, s. 352-362
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Tidskriftsartikel (refereegranskat)abstract
- Higher crop production and higher water use efficiency are usually achieved simultaneously with surface drip irrigation compared to other surface irrigation methods. With increasing competition for fresh water nowadays, there is also a need for greater use of brackish water in agriculture. Effects of soil hydraulic properties, initial soil moisture content ( ), and the irrigation regime on soil water and salinity distribution under surface drip irrigation (DI) with brackish irrigation water for growing tomato in saline soil were investigated using HYDRUS-2D/3D model. Simulation scenarios were conducted including three soil types (sand, loamy sand, and sandy loam), two irrigation regimes (daily and on alternate-day irrigation), and two values. Simulation results revealed that the effect of the irrigation regime on the wetting patterns differed according to the soil’s hydraulic properties while the effect of the initial soil moisture content vanished after a few days. Alternate-day regime is suitable for fine-texture soil. Soil salinity patterns showed that the irrigation regime and value did not show any significant effect on soil salinity distribution under drip irrigation with brackish water. Higher soil salinity values occurred along the soil surface by the end of the simulation period. These higher values were closer to the emitter in sand as compared to loamy sand and sandy loam. Water balance calculations showed that as the initial soil moisture content increased, the free drainage component increased. However, the irrigation regime and initial soil moisture content value did not affect the evaporation rate and root water uptake rate.
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| 48. |
- Aboulila, Tarek Selim, et al.
(författare)
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Soil water and salinity distribution under different treatments of drip irrigation.
- 2013
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Ingår i: Soil Science Society of America Journal. - : Wiley. - 0361-5995. ; 77:4, s. 1144-1156
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- In this study, field experiments and numerical simulations for different drip irrigation treatments in a sandy loam soil were conducted to investigate soil water and salinity distribution as well as dye infiltration patterns. Three treatments, surface drip irrigation without and with plastic mulch (T1 and T2, respectively); and subsurface drip irrigation (T3), were used. In addition, daily and bi-weekly irrigation regimes were considered during performing each treatment. After ceasing the designed irrigation schedule of each treatment, horizontal soil sections were dug with 10 cm intervals. Then, dye patterns were captured using a digital camera and soil water and pore water electric conductivity were measured by a WET-sensor. Experiments results revealed that maximum dye infiltration depth and maximum dye coverage volume occurred during the bi-weekly irrigation regime and in T3. Daily irrigation regime kept the top soil layer moist with adequate amount of soil water as compared to bi-weekly regime. Moreover, T2 provided higher soil water content within the soil domain as compared to other treatments. The simulation results also demonstrated that model prediction for soil moisture distribution within the flow domain was excellent. Furthermore, T2 and daily irrigation showed lower salinity levels in the flow domain as compared to other irrigation treatments and regimes. In sum, mulching treatment with daily irrigation regime is recommended for arid areas over other drip irrigation treatments and regimes. In addition, HYDRUS-2D/3D can be used as a fast and cost effective assessment tool for water flow and salt movement for specific sites having similar soil conditions.
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| 49. |
- Aboulila, Tarek Selim, et al.
(författare)
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Spatial Analysis of Infiltration Experiment
- 2011
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Ingår i: Australian Journal of Basic and Applied Sciences. - 1991-8178. ; 5:7, s. 729-742
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Tidskriftsartikel (refereegranskat)abstract
- Developing correlations between various soil parameters are considered the major challenge to diminish time and cost associated with field measurements. Soil hydraulic and physical properties were extensively characterized using tension disc infiltrometer and soil sampling in a silty clay agricultural field in Kalaat El-Andalous, Tunisia. Tension disc infiltrometer experiments were conducted at 109 plots with two supply water potentials (-30,-60 mm) at each plot to determine the hydraulic conductivity, sorptivity, capillary length, and matric flux potential. In addition, soil samples were analyzed to determine the soil bulk density, and water content. From the statistical and spatial analysis for the different parameters, it was found that the soil hydraulic parameters had larger variability than bulk density. Sorptivity, capillary length, matric flux potential, and bulk density had lager variance with the distance between the plots. No correlation was found between bulk density and the soil hydraulic parameters, nor could the soil hydraulic parameters be correlated to each other.
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| 50. |
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