| 1. |
|
|
| 2. |
- Klionsky, Daniel J., et al.
(författare)
-
Guidelines for the use and interpretation of assays for monitoring autophagy
- 2012
-
Ingår i: Autophagy. - : Informa UK Limited. - 1554-8635 .- 1554-8627. ; 8:4, s. 445-544
-
Forskningsöversikt (refereegranskat)abstract
- In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.
|
|
| 3. |
- Wang, Li-San, et al.
(författare)
-
Rarity of the Alzheimer Disease-Protective APP A673T Variant in the United States.
- 2015
-
Ingår i: JAMA neurology. - : American Medical Association (AMA). - 2168-6157 .- 2168-6149. ; 72:2
-
Tidskriftsartikel (refereegranskat)abstract
- Recently, a rare variant in the amyloid precursor protein gene (APP) was described in a population from Iceland. This variant, in which alanine is replaced by threonine at position 673 (A673T), appears to protect against late-onset Alzheimer disease (AD). We evaluated the frequency of this variant in AD cases and cognitively normal controls to determine whether this variant will significantly contribute to risk assessment in individuals in the United States.
|
|
| 4. |
- Conley, Robert B., et al.
(författare)
-
Secondary Fracture Prevention : Consensus Clinical Recommendations from a Multistakeholder Coalition
- 2020
-
Ingår i: Journal of Orthopaedic Trauma. - 0890-5339. ; 34:4, s. 125-141
-
Tidskriftsartikel (refereegranskat)abstract
- Osteoporosis-related fractures are undertreated, due in part to misinformation about recommended approaches to patient care and discrepancies among treatment guidelines. To help bridge this gap and improve patient outcomes, the American Society for Bone and Mineral Research assembled a multistakeholder coalition to develop clinical recommendations for the optimal prevention of secondary fractureamong people aged 65 years and older with a hip or vertebral fracture. The coalition developed 13 recommendations (7 primary and 6 secondary) strongly supported by the empirical literature. The coalition recommends increased communication with patients regarding fracture risk, mortality and morbidity outcomes, and fracture risk reduction. Risk assessment (including fall history) should occur at regular intervals with referral to physical and/or occupational therapy as appropriate. Oral, intravenous, andsubcutaneous pharmacotherapies are efficaciousandcanreduce risk of future fracture.Patientsneededucation,however, about thebenefitsandrisks of both treatment and not receiving treatment. Oral bisphosphonates alendronate and risedronate are first-line options and are generally well tolerated; otherwise, intravenous zoledronic acid and subcutaneous denosumab can be considered. Anabolic agents are expensive butmay be beneficial for selected patients at high risk.Optimal duration of pharmacotherapy is unknown but because the risk for second fractures is highest in the earlypost-fractureperiod,prompt treatment is recommended.Adequate dietary or supplemental vitaminDand calciumintake shouldbe assured. Individuals beingtreatedfor osteoporosis shouldbe reevaluated for fracture risk routinely, includingvia patienteducationabout osteoporosisandfracturesandmonitoringfor adverse treatment effects.Patients shouldbestronglyencouraged to avoid tobacco, consume alcohol inmoderation atmost, and engage in regular exercise and fall prevention strategies. Finally, referral to endocrinologists or other osteoporosis specialists may be warranted for individuals who experience repeated fracture or bone loss and those with complicating comorbidities (eg, hyperparathyroidism, chronic kidney disease).
|
|
| 5. |
- Conley, Robert B., et al.
(författare)
-
Secondary Fracture Prevention : Consensus Clinical Recommendations from a Multistakeholder Coalition
- 2020
-
Ingår i: Orthopaedic Nursing. - 0744-6020. ; 39:3, s. 145-161
-
Tidskriftsartikel (refereegranskat)abstract
- Osteoporosis-related fractures are undertreated, due in part to misinformation about recommended approaches to patient care and discrepancies among treatment guidelines. To help bridge this gap and improve patient outcomes, the American Society for Bone and Mineral Research assembled a multistakeholder coalition to develop clinical recommendations for the optimal prevention of secondary fracture among people aged 65 years and older with a hip or vertebral fracture. The coalition developed 13 recommendations (7 primary and 6 secondary) strongly supported by the empirical literature. The coalition recommends increased communication with patients regarding fracture risk, mortality and morbidity outcomes, and fracture risk reduction. Risk assessment (including fall history) should occur at regular intervals with referral to physical and/or occupational therapy as appropriate. Oral, intravenous, and subcutaneous pharmacotherapies are efficacious and can reduce risk offuture fracture. Patients need education, however, about the benefits and risks of both treatment and not receiving treatment. Oral bisphosphonates alendronate and risedronate are first-line options and are generally well tolerated; otherwise, intravenous zoledronic acid and subcutaneous denosumab can be considered. Anabolic agents are expensive but may be beneficial for selected patients at high risk. Optimal duration of pharmacotherapy is unknown but because the riskfor second fractures is highest in the early post-fracture period, prompt treatment is recommended. Adequate dietary or supplemental vitamin D and calcium intake should be assured. Individuals being treated for osteoporosis should be reevaluated for fracture risk routinely, including via patient education about osteoporosis and fractures and monitoring foradverse treatment effects. Patients should be strongly encouraged to avoid tobacco, consume alcohol in moderation at most, and engage in regular exercise and fall prevention strategies. Finally, referral to endocrinologists or other osteoporosis specialists may be warranted for individuals who experience repeated fracture or bone loss and those with complicating comorbidities (eg, hyperparathyroidism, chronic kidney disease). (c) 2019 American Society for Bone and Mineral Research.
|
|
| 6. |
- Nguyen, Thanh N, et al.
(författare)
-
Global Impact of the COVID-19 Pandemic on Stroke Volumes and Cerebrovascular Events: A 1-Year Follow-up.
- 2023
-
Ingår i: Neurology. - 1526-632X. ; 100:4
-
Tidskriftsartikel (refereegranskat)abstract
- Declines in stroke admission, IV thrombolysis (IVT), and mechanical thrombectomy volumes were reported during the first wave of the COVID-19 pandemic. There is a paucity of data on the longer-term effect of the pandemic on stroke volumes over the course of a year and through the second wave of the pandemic. We sought to measure the effect of the COVID-19 pandemic on the volumes of stroke admissions, intracranial hemorrhage (ICH), IVT, and mechanical thrombectomy over a 1-year period at the onset of the pandemic (March 1, 2020, to February 28, 2021) compared with the immediately preceding year (March 1, 2019, to February 29, 2020).We conducted a longitudinal retrospective study across 6 continents, 56 countries, and 275 stroke centers. We collected volume data for COVID-19 admissions and 4 stroke metrics: ischemic stroke admissions, ICH admissions, IVT treatments, and mechanical thrombectomy procedures. Diagnoses were identified by their ICD-10 codes or classifications in stroke databases.There were 148,895 stroke admissions in the 1 year immediately before compared with 138,453 admissions during the 1-year pandemic, representing a 7% decline (95% CI [95% CI 7.1-6.9]; p < 0.0001). ICH volumes declined from 29,585 to 28,156 (4.8% [5.1-4.6]; p < 0.0001) and IVT volume from 24,584 to 23,077 (6.1% [6.4-5.8]; p < 0.0001). Larger declines were observed at high-volume compared with low-volume centers (all p < 0.0001). There was no significant change in mechanical thrombectomy volumes (0.7% [0.6-0.9]; p = 0.49). Stroke was diagnosed in 1.3% [1.31-1.38] of 406,792 COVID-19 hospitalizations. SARS-CoV-2 infection was present in 2.9% ([2.82-2.97], 5,656/195,539) of all stroke hospitalizations.There was a global decline and shift to lower-volume centers of stroke admission volumes, ICH volumes, and IVT volumes during the 1st year of the COVID-19 pandemic compared with the prior year. Mechanical thrombectomy volumes were preserved. These results suggest preservation in the stroke care of higher severity of disease through the first pandemic year.This study is registered under NCT04934020.
|
|
| 7. |
|
|
| 8. |
- Dimkovski, Zlate, et al.
(författare)
-
Interference Measurements of Deposits on Cylinder Liner Surfaces
- 2011
-
Ingår i: Wear. - Amsterdam : Elsevier. - 0043-1648 .- 1873-2577. ; 270:3-4, s. 247-251
-
Tidskriftsartikel (refereegranskat)abstract
- The accumulation of deposits in the honing grooves of the cylinder liner surfaces of internal combustion engines is undesirable as they seal the grooves (reducing their oil retention capability) and increase engine's oil consumption. As part of a long-term programme of truck engine development, after different running times and under similar conditions of load, engine speed and lubrication, a number of grey iron cylinder liners were axially sectioned, measured, inspected and a presence of deposits was discovered. These deposits were characterised in order to gain knowledge about their origin and quantities. The X-ray energy dispersive analysis revealed elements stemming from the oil/fuel (C, O and S), from the detergent (Ca and Mg), from the anti-wear additive (Zn and P), and from some contaminants (K and Si). Higher concentration of S and Ca were mostly found in the honing grooves covered with deposits suggesting a domination of the detergent additive. Deposit thickness measurements obtained by a white light interferometer revealed patchy deposit topographies concentrated at the top region reducing towards the bottom of the liner which was also confirmed by scanning electron microscope measurements. Despite the limitations of the interferometer, it has been shown that the interference measurements are sufficiently reliable for a quick and objective quantification of the overall deposit accumulation.
|
|
| 9. |
- Wahlund, Björn, et al.
(författare)
-
EEG data, fractal dimension and multivariate statistics
- 2010
-
Ingår i: Journal of Computer Science and Engineering. - 2043-9091. ; 3:1, s. 10-16
-
Tidskriftsartikel (refereegranskat)abstract
- The objective of this paper is to discuss the concept of Inverse Problem, i.e. how to obtain information via data about a complex mathematical model. We propose that by merging ideas from applied mathematics with ideas from multivariate statistical inference it is possible to find solutions or good approximation of many complex scientific problems.
|
|
| 10. |
|
|
| 11. |
|
|
| 12. |
- Anderberg, Cecilia, et al.
(författare)
-
Combined SEM and Stylus Profiling Sensoring for Improved Cylinder Liner Honing
- 2006
-
Ingår i: Proceedings of Austrib 06 - International Tribology Conference. - Brisbane : Queensland University of Technology. ; , s. 6-
-
Konferensbidrag (refereegranskat)abstract
- The demands on decreased environmental impact from vehicles are resulting in a strong push for decreased engine oil and fuel consumption.Recent engine tests have shown a promising reduction in oil consumption when using cylinder liners with a smoother finish than the current plateau honing.One approach to produce smoother liner surfaces is to replace SiC ceramic honing stones with diamond tools. However, even though the diamond honing process results in higher productivity, improved quality control is needed to monitor the degree of cold worked material - “blechmantel” (German), and the resulting risk of increased wear and scuffing.A number of petrol and diesel engine cylinder liners have been mapped to be able to verify the quality and consequences, in terms of wear and function, of the honing process. A new mapping method, combining SEM images and quantitative image analysis with traditional 2D profilometry has been developed and tested in this study. The surface mapping method developed was employed before and after the test to study effect of running-in wear on the surface, features characterized with the SEM- and the 2D profilometer.The results show that combining SEM- and profilometric methods gives a good picture of the effects of varying the cylinder liner pressure and roughness. The core roughness decreases more for diesel liners than for petrol liners.. A probable cause is that the more severe diesel high pressure run-in conditions are able to effectively “truncate” the plateaux and remove residing plastically deformed un-cut honing residues while the less severe petrol liner conditions do not manage to remove the blechmantel and irregularities to an important extent.
|
|
| 13. |
- Anderberg, Cecilia, et al.
(författare)
-
Cylinder Liners and Consequences of Improved Honing
- 2006
-
Ingår i: Proceedings of Nordtrib conference 2006, Helsingor, Danemark. ; , s. 13-
-
Konferensbidrag (refereegranskat)abstract
- The demands on decreased environmental impact from vehicles are resulting in a strong push for decreased engine oil and fuel consumption. Engine oil and fuel consumption are to a great extent controlled by the topography of the cylinder liner surface.Recent engine tests have shown a promising reduction in oil consumption when using cylinder liners with a smoother finish than the current plateau honing.One approach to produce smoother liner surfaces is to replace SiC ceramic honing stones with diamond tools. However, event though the diamond honing process results in higher productivity, improved demands of quality control is needed to monitor the degree of cold worked material - “blechmantel” (German), and the resulting risk of increased wear and scuffing.A number of petrol and diesel engine cylinder liners have been mapped to be able to verify the quality and consequences, in terms of wear and function, of the honing process. A new mapping method, combining SEM images and quantitative image analysis with traditional 2D profilometry has been developed and tested in this study. The liners where tested in a reciprocating rig of 8 mm stroke and with a frequency of 10 Hz, simulating the top-dead center conditions in a running engine.The tests where carried out in high- and low pressure conditions with smooth respectively rough liner roughnesses against PVD coated piston rings. The developed surface mapping method was employed before and after the test to study effect of running-in wear on the surface, features characterized with the SEM- and the 2D profilometer.The results show that combining SEM- and profilometric methods gives a good picture of the effects of varying the cylinder liner pressure and roughness. The core roughness decrease more for diesel liners than for petrol liners. In average (rough and smooth liners) the diesel core roughness decrease 265% while the petrol liners average on a 60% decrease. Blechmantel- and Irregularities ratio show a high sensitivity to varying conditions and decrease 1180% to 100% for the diesel liners while the parameters increase between 106% to 18% for all the petrol liners. A probable cause is the more severe diesel high pressure run-in conditions are able to effectively “truncate” the plateaux and remove residing plastically deformed un-cut honing residues while the less severe petrol liner conditions not manage to remove the blechmantel and irregularities in an important extent.
|
|
| 14. |
- Anderberg, Cecilia, et al.
(författare)
-
Wear Resistance of Smooth Automotive Cylinder Liner Surfaces
- 2005
-
Ingår i: World Tribology Congress III, Volume 2. - New York, NY : ASME Press. - 0791842029 ; , s. 603-604
-
Konferensbidrag (refereegranskat)abstract
- Demands for decreased environmental impact from vehicles are resulting in a strong push for decreased engine oil, fuel consumption and weight. New machining and coating technologies have offered ways to attack these problems. Engine oil and fuel consumption are to a great extent controlled by the topography of the cylinder liner surface and it is therefore important to optimise this surface. Recent engine tests have shown a reduction in oil consumption when using cylinder liners with a smoother finish than that given by the current plateau honing. However, engine manufacturers are hesitant to introduce smoother liner surfaces because of fears of severe wear and scuffing. There is also the possibility that smoother liner surfaces may be more sensitive to the choice of piston ring finishes. This paper therefore seeks to investigate the functional performance and resistance to wear of these smooth cylinder liners and the mating top ring surfaces. Copyright © 2005 by ASME
|
|
| 15. |
- Anderson, Robert, 1988, et al.
(författare)
-
What's the point? The contribution of a sustainability view in contaminated site remediation
- 2018
-
Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 630, s. 103-116
-
Tidskriftsartikel (refereegranskat)abstract
- Decision support tools (DST) are often used in remediation projects to aid in the complex decision on how best to remediate a contaminated site. In recent years, the sustainable remediation concept has brought increased attention to the often-overlooked contradictory effects of site remediation, with a number of sustainability assessment tools now available. The aim of the present study is twofold: (1) to demonstrate how and when different assessment views affect the decision support outcome on remediation alternatives in a DST, and (2) to demonstrate the contribution of a full sustainability assessment. The SCORE tool was used in the analysis; it is based on a holistic multi-criteria decision analysis (MCDA) approach, assessing sustainability in three dimensions: environmental, social, and economic. Four assessment scenarios, compared to a full sustainability assessment, were considered to reflect different possible assessment views; considering public and private problem owner perspectives, as well as green and traditional assessment scopes. Four real case study sites in Sweden were analyzed. The results show that the decision support outcome from a full sustainability assessment most often differs to that of other assessment views, and results in remediation alternatives which balance trade-offs in most of the scenarios. In relation to the public perspective and traditional scope, which is seen to lead to the most extensive and expensive remediation alternatives, the trade-off is related to less contaminant removal in favour of reduced negative secondary effects such as emissions and waste disposal. Compared to the private perspective, associated with the lowest cost alternatives, the trade-off is higher costs, but more positive environmental and social effects. Generally, both the green and traditional assessment scopes miss out on relevant social and local environmental secondary effects which may ultimately be very important for the actual decision in a remediation project.
|
|
| 16. |
- Baskaran, Karthikeyan, et al.
(författare)
-
Benefit of Adaptive Optics Aberration Correction at Preferred Retinal Locus
- 2012
-
Ingår i: Optometry and Vision Science. - 1040-5488 .- 1538-9235. ; 89:9, s. 1417-1423
-
Tidskriftsartikel (refereegranskat)abstract
- PURPOSE.: To investigate the effect of eccentric refractive correction and full aberration correction on both high- and low-contrast grating resolution at the preferred retinal locus (PRL) of a single low-vision subject with a long-standing central scotoma. METHODS.: The subject was a 68-year-old women with bilateral absolute central scotoma due to Stargardt disease. She developed a single PRL located 25 degrees nasally of the damaged macula in her left eye, this being the better of the two eyes. High- (100%) and low-contrast (25 and 10%) grating resolution acuity was evaluated using four different correction conditions. The first two corrections were solely refractive error corrections, namely, habitual spectacle correction and full spherocylindrical correction. The latter two corrections were two versions of adaptive optics corrections of all aberrations, namely, habitual spectacle correction with aberration correction and full spherocylindrical refractive correction with aberration correction. RESULTS.: The mean high-contrast (100%) resolution acuity with her habitual correction was 1.06 logMAR, which improved to 1.00 logMAR with full spherocylindrical correction. Under the same conditions, low-contrast (25%) acuity improved from 1.30 to 1.14 logMAR. With adaptive optics aberration correction, the high-contrast resolution acuities improved to 0.89/0.92 logMAR and the low-contrast acuities improved to 1.04/1.06 logMAR under both correction modalities. The low-contrast (10%) resolution acuity was 1.34 logMAR with adaptive optics aberration correction; however, with purely refractive error corrections, she was unable to identify the orientation of the gratings. CONCLUSIONS.: Correction of all aberrations using adaptive optics improves both high- and low-contrast resolution acuity at the PRL of a single low-vision subject with long-standing absolute central scotoma
|
|
| 17. |
- Baskaran, Karthikeyan, et al.
(författare)
-
Effects of Optical Defocus on Resolution Acuity in Preferred Retinal Locus
- 2011
-
Ingår i: <em>Invest Ophthalmol Vis Sci</em> 2011;52: E-Abstract 1900..
-
Konferensbidrag (refereegranskat)abstract
- PurposeResolution acuity in the peripheral visual field is primarily limited by retinal sampling. In healthy eyes, the correction of peripheral refractive errors does not produce significant visual benefits other than improved detection and low contrast acuity. However, studies (Lundstrom L et al, Optom Vis Sci, 2007;84:1046-52) have shown that peripheral refractive corrections improve resolution acuity in subjects with central visual field loss (CFL) who have an established preferred retinal locus (PRL). The aim of this study was to evaluate the effect of optical defocus on high contrast resolution acuity in the PRL. MethodsResolution acuity was evaluated under spherical defocus in the PRL of three low vision subjects (mean age 75 years) with long standing CFL (due to age-related macular degeneration). Off-axis refractive error at the PRL was measured by an open-field COAS-HD VR aberrometer and was corrected accordingly. The PRL for subject 1 was located at 10{degrees} in the temporal visual field (left eye), subject 2 at 20{degrees} in the nasal visual field (right eye) and subject 3 at 15{degrees} in the inferior visual field (left eye). Stimuli consisting of high-contrast Gabor patches with a visible diameter of 3{o} were presented on a CRT monitor situated 1.0 meter from the subject. Resolution thresholds for static visual acuity (SVA) and dynamic visual acuity (DVA) were obtained using an adaptive Bayesian algorithm. Fixation was aided using illuminated concentric rings covering {+/-}25{degrees} in the visual field. Defocus was altered in 1D steps up to {+/-}4D. When measuring DVA, the sine-wave gratings drifted within the Gaussian envelope at an angular velocity of 1{degrees}/sec. ResultsResolution thresholds for both SVA and DVA in the PRL varied significantly with the amount of optical defocus. The results show a 2 - 3 line decrease (logMAR) in SVA and DVA with 4 D positive and negative defocus. There was no significant difference between SVA and DVA with increasing defocus. In the absence of defocus, SVA was significantly better than DVA in the PRL. ConclusionsDefocus as low as one dioptre has an impact on both static and dynamic high contrast resolution acuity for CFL subjects using a PRL. The results of this study suggest that, for CFL subjects using a PRL, resolution acuity is not only sampling limited but also influenced by the optics of the eye.
|
|
| 18. |
- Bolin, Sara, 1988-, et al.
(författare)
-
Dormant SOX9-positive cells behind MYC-driven medulloblastoma recurrence
-
Tidskriftsartikel (refereegranskat)abstract
- Tumor recurrence is a slow biological process involving therapy resistance, immune escape, and metastasis and is the leading cause of death in medulloblastoma, the most frequent malignant pediatric brain tumor. By studying paired primary-recurrent patient samples and patient-derived xenografts we identified a significant accumulation of SOX9-positive cells in relapses and metastases. They exist as rare, quiescent cells in Group 3 and Group 4 patients that constitute two-thirds of medulloblastoma. To follow relapse at the single-cell level we developed an inducible dual Tet model of MYC-driven MB, where MYC can be directed from treatment-sensitive bulk cells to resistant, dormant SOX9-positive cells by doxycycline. SOX9 promoted immune es-cape, DNA repair suppression and was essential for recurrence. Tumor cell dormancy was non-hierarchical, migratory, and depended on MYC suppression by SOX9 to promote relapse. By using computational modeling and treatment we further showed how doxorubicin and MGMT inhibitors are specifically targeting relapsing cells.
|
|
| 19. |
- Borgenvik, Anna, 1987-, et al.
(författare)
-
Dormant SOX9-Positive Cells Facilitate MYC-Driven Recurrence of Medulloblastoma
- 2022
-
Ingår i: Cancer Research. - : AMER ASSOC CANCER RESEARCH. - 0008-5472 .- 1538-7445. ; 82:24, s. 4586-4603
-
Tidskriftsartikel (refereegranskat)abstract
- Relapse is the leading cause of death in patients with medulloblas-toma, the most common malignant pediatric brain tumor. A better understanding of the mechanisms underlying recurrence could lead to more effective therapies for targeting tumor relapses. Here, we observed that SOX9, a transcription factor and stem cell/glial fate marker, is limited to rare, quiescent cells in high-risk medulloblastoma with MYC amplification. In paired primary-recurrent patient samples, SOX9-positive cells accumulated in medulloblastoma relapses. SOX9 expression anti-correlated with MYC expression in murine and human medulloblastoma cells. However, SOX9-positive cells were plastic and could give rise to a MYC high state. To follow relapse at the single-cell level, an inducible dual Tet model of medulloblastoma was developed, in which MYC expression was redirected in vivo from treatment-sensitive bulk cells to dormant SOX9-positive cells using doxycycline treatment. SOX9 was essential for relapse initiation and depended on suppression of MYC activity to promote therapy resistance, epithelial-mesenchymal transition, and immune escape. p53 and DNA repair pathways were downregulated in recurrent tumors, whereas MGMT was upregulated. Recurrent tumor cells were found to be sensitive to treatment with an MGMT inhibitor and doxorubicin. These findings suggest that recurrence-specific targeting coupled with DNA repair inhibition comprises a potential therapeutic strategy in patients affected by medulloblastoma relapse.Significance: SOX9 facilitates therapy escape and recurrence in medulloblastoma via temporal inhibition of MYC/MYCN genes, revealing a strategy to specifically target SOX9-positive cells to prevent tumor relapse.
|
|
| 20. |
- Brigham-Grette, Julie, et al.
(författare)
-
Pliocene warmth, polar amplification, and stepped pleistocene cooling recorded in NE arctic russia
- 2013
-
Ingår i: Science. - : American Association for the Advancement of Science. - 0036-8075 .- 1095-9203. ; 340:6139, s. 1421-1427
-
Tidskriftsartikel (refereegranskat)abstract
- Understanding the evolution of Arctic polar climate from the protracted warmth of the middle Pliocene into the earliest glacial cycles in the Northern Hemisphere has been hindered by the lack of continuous, highly resolved Arctic time series. Evidence from Lake El'gygytgyn, in northeast (NE) Arctic Russia, shows that 3.6 to 3.4 million years ago, summer temperatures were similar to 8 degrees C warmer than today, when the partial pressure of CO2 was similar to 400 parts per million. Multiproxy evidence suggests extreme warmth and polar amplification during the middle Pliocene, sudden stepped cooling events during the Pliocene-Pleistocene transition, and warmer than present Arctic summers until similar to 2.2 million years ago, after the onset of Northern Hemispheric glaciation. Our data are consistent with sea-level records and other proxies indicating that Arctic cooling was insufficient to support large-scale ice sheets until the early Pleistocene.
|
|
| 21. |
- Čančer, Matko, et al.
(författare)
-
Humanized Stem Cell Models of Pediatric Medulloblastoma Reveal an Oct4/mTOR Axis that Promotes Malignancy
- 2019
-
Ingår i: Cell Stem Cell. - : CELL PRESS. - 1934-5909 .- 1875-9777. ; 25:6, s. 855-870
-
Tidskriftsartikel (refereegranskat)abstract
- Medulloblastoma (MB), the most frequent malignant childhood brain tumor, can arise from cellular malfunctions during hindbrain development. Here we generate humanized models for Sonic Hedgehog (SHH)-subgroup MB via MYCN overexpression in primary human hindbrain-derived neuroepithelial stem (hbNES) cells or iPSC-derived NES cells, which display a range of aggressive phenotypes upon xenografting. iPSC-derived NES tumors develop quickly with leptomeningeal dissemination, whereas hbNES-derived cells exhibit delayed tumor formation with less dissemination. Methylation and expression profiling show that tumors from both origins recapitulate hallmarks of infant SHH MB and reveal that mTOR activation, as a result of increased Oct4, promotes aggressiveness of human SHH tumors. Targeting mTOR decreases cell viability and prolongs survival, showing the utility of these varied models for dissecting mechanisms mediating tumor aggression and demonstrating the value of humanized models for a better understanding of pediatric cancers.
|
|
| 22. |
|
|
| 23. |
- Dengler, Juergen, et al.
(författare)
-
GrassPlot - a database of multi-scale plant diversity in Palaearctic grasslands
- 2018
-
Ingår i: Phytocoenologia. - : Schweizerbart. - 0340-269X. ; 48:3, s. 331-347
-
Tidskriftsartikel (refereegranskat)abstract
- GrassPlot is a collaborative vegetation-plot database organised by the Eurasian Dry Grassland Group (EDGG) and listed in the Global Index of Vegetation-Plot Databases (GIVD ID EU-00-003). GrassPlot collects plot records (releves) from grasslands and other open habitats of the Palaearctic biogeographic realm. It focuses on precisely delimited plots of eight standard grain sizes (0.0001; 0.001;... 1,000 m(2)) and on nested-plot series with at least four different grain sizes. The usage of GrassPlot is regulated through Bylaws that intend to balance the interests of data contributors and data users. The current version (v. 1.00) contains data for approximately 170,000 plots of different sizes and 2,800 nested-plot series. The key components are richness data and metadata. However, most included datasets also encompass compositional data. About 14,000 plots have near-complete records of terricolous bryophytes and lichens in addition to vascular plants. At present, GrassPlot contains data from 36 countries throughout the Palaearctic, spread across elevational gradients and major grassland types. GrassPlot with its multi-scale and multi-taxon focus complements the larger international vegetationplot databases, such as the European Vegetation Archive (EVA) and the global database " sPlot". Its main aim is to facilitate studies on the scale-and taxon-dependency of biodiversity patterns and drivers along macroecological gradients. GrassPlot is a dynamic database and will expand through new data collection coordinated by the elected Governing Board. We invite researchers with suitable data to join GrassPlot. Researchers with project ideas addressable with GrassPlot data are welcome to submit proposals to the Governing Board.
|
|
| 24. |
- DeVita, Michael A., et al.
(författare)
-
"Identifying the hospitalised patient in crisis"-A consensus conference on the afferent limb of Rapid Response Systems
- 2010
-
Ingår i: Resuscitation. - : Elsevier BV. - 1873-1570 .- 0300-9572. ; 81:4, s. 375-382
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Most reports of Rapid Response Systems (RRS) focus on the efferent, response component of the system, although evidence suggests that improved vital sign monitoring and recognition of a clinical crisis may have outcome benefits. There is no consensus regarding how best to detect patient deterioration or a clear description of what constitutes patient monitoring. Methods: A consensus conference of international experts in safety, RRS, healthcare technology, education, and risk prediction was convened to review current knowledge and opinion on clinical monitoring. Using established consensus procedures, four topic areas were addressed: (1) To what extent do physiologic abnormalities predict risk for patient deterioration? (2) Do workload changes and their potential stresses on the healthcare environment increase patient risk in a predictable manner? (3) What are the characteristics of an "ideal" monitoring system, and to what extent does currently available technology meet this need? and (4) How can monitoring be categorized to facilitate comparing systems? The major findings include: (1) vital sign aberrations predict risk, (2) monitoring patients more effectively may improve outcome, although some risk is random, (3) the workload implications of monitoring on the clinical workforce have not been explored, but are amenable to study and should be investigated, (4) the characteristics of an ideal monitoring system are identifiable, and it is possible to categorize monitoring modalities. It may also be possible to describe monitoring levels, and a system is proposed. (C) 2010 Elsevier Ireland Ltd. All rights reserved.
|
|
| 25. |
- Dimkovski, Zlate, 1974-, et al.
(författare)
-
Characterisation of Cylinder Liner Honing Textures for Production Control
- 2013
-
Ingår i: Characterisation of Areal Surface Texture. - Berlin : Springer Berlin/Heidelberg. - 9783642364570 - 9783642364587 ; , s. 281-302
-
Bokkapitel (refereegranskat)abstract
- It is of common interest to reduce oil consumption and frictional losses in internal combustion engines, which are heavily influenced by the quality of the cylinder liner surface. The plateau cross-hatch topography of a cylinder liner consists of a system of grooves of different density, width and depth, some parts covered by folded metal, and some parts totally interrupted and unbalanced as a result of imperfection in the honing process. These grooves are critical for good liner function, and need to be quickly and objectively quantified for an efficient surface finish development. A suitable way to do this is to use 3D interference measurements and to combine profile and image analysis. Thus, the features/parameters, such as honing angle, balance of honing texture, groove interrupts, width, height, and distance between grooves, are successively quantified. Here, these parameters, along with areal surface texture parameters in the published ISO specification standard were used in two case studies. The first case study is on the effect of the folded metal on the surfaces of run truck liners and the second is an evaluation of the improvements of the surface quality introduced by the diamond honing in production of car liners. In addition, based on the significant parameters of the surface, a general characterisation tool for qualifying the surface quality and determination of the required number of measurements is presented. © 2013 Springer-Verlag Berlin Heidelberg. All rights are reserved.
|
|
| 26. |
- Dimkovski, Zlate, et al.
(författare)
-
Characterisation of worn cylinder liner surfaces by segmentation of honing and wear scratches
- 2011
-
Ingår i: Wear. - Amsterdam : Elsevier. - 0043-1648 .- 1873-2577. ; 271, s. 548-552
-
Tidskriftsartikel (refereegranskat)abstract
- The presence of the honing scratches/grooves in cylinder liner surfaces is intended and desired as they improve the lubrication and retain the debris reducing the piston assembly/liner friction and consequently improve the fuel economy and longevity of the internal combustion (IC) engines. Axial scratches caused by the abrasive wear between the tribological partners and/or entrained wear particles are undesired since they are correlated with increased oil consumption and noxious emissions of the IC engines. Due to the imperfection of the manufacturing process, the honing grooves, especially the deep ones, are smeared and interrupted by folds. A portion of the folds would eventually detach during the running process and act as abrasive particles increasing the wear in the cylinder. To closely examine the influence of all these features on the liner's function, it emerges a need to objectively quantify the axial wear scratches, plateau honing grooves, deep honing grooves and their interrupts. The existing techniques fail to segment a groove containing interrupts as they usually appear as summits at several locations in the course of the groove. Combining the profile and image analyses, the deep grooves and their interrupts were successfully identified and quantified in earlier works of the authors. In this paper those algorithms are extended, so that the deep honing grooves, plateau honing grooves and axial scratches crossing different depth levels are sequentially segmented in three levels/steps in an immersing way. A number of parameters derived from this method were utilised to compare 3D interference measurements from the top dead centre, middle and bottom region of a liner run in a truck engine test whereas the three regions represent different wear regimes due to the different running conditions. The results show that: (i) the axial scratches are densest in the top dead centre and about the same size as the plateau grooves in all three regions, while in the bottom region there are only few scratches; (ii) the presence of plateau grooves in the top region clearly decreases, (iii) the deep groove interrupt and coverage are lowest in the top region, and (iv) the groove height and distance between grooves spread mostly.
|
|
| 27. |
- Dimkovski, Zlate, et al.
(författare)
-
Characterisation of Worn Cylinder Liner Surfaces by Segmentation of Honing and Wear Scratches
- 2009
-
Ingår i: Proceedings of the 12th International Conference on Metrology and Properties of Engineering Surfaces. - Rzesow, Poland : Rzeszow University of Technology. - 9788371995453 ; , s. 187-192
-
Konferensbidrag (refereegranskat)abstract
- The presence of the honing scratches/grooves in cylinder liner surfaces is intended and desired as they improve the lubrication and retain the debris reducing the piston assembly/liner friction and consequently improve the fuel economy and longevity of the internal combustion (IC) engines. Axial scratches caused by the abrasive wear between the tribological partners and/or entrained wear particles are undesired since they are correlated with increased oil consumption and noxious emissions of the IC engines. Due to the imperfection of the manufacturing process, the honing grooves, especially the deep ones, are smeared and interrupted by folds. A portion of the folds would eventually detach during the running process and act as abrasive particles increasing the wear in the cylinder. To closely examine the influence of all these features on the liner's function, it emerges a need to objectively quantify the axial wear scratches, plateau honing grooves, deep honing grooves and their interrupts. The existing techniques fail to segment a groove containing interrupts as they usually appear as summits at several locations in the course of the groove. Combining the profile and image analyses, the deep grooves and their interrupts were successfully identified and quantified in earlier works of the authors. In this paper those algorithms are extended, so that the deep honing grooves, plateau honing grooves and axial scratches crossing different depth levels are sequentially segmented in three levels/steps in an immersing way. A number of parameters derived from this method were utilised to compare 3D interference measurements from the top dead centre, middle and bottom region of a liner run in a truck engine test whereas the three regions represent different wear regimes due to the different running conditions. The results show that: (i) the axial scratches are densest in the top dead centre and about the same size as the plateau grooves in all three regions, while in the bottom region there are only few scratches; (ii) the presence of plateau grooves in the top region clearly decreases, (iii) the deep groove interrupt and coverage are lowest in the top region, and (iv) the groove height and distance between grooves spread mostly. © 2010 Elsevier B.V. All rights reserved.
|
|
| 28. |
- Dimkovski, Zlate, et al.
(författare)
-
Complementing 3D Roughness Parameters for Monitoring of Improved Honing of Cylinder Bores
- 2008
-
Ingår i: Proceedings of the Swedish Production Symposium (SPS) - 2008. - 9783939026952
-
Konferensbidrag (refereegranskat)abstract
- It is of common interest to reduce the oil consumption and frictional losses in the internal combustion engines which are in a great deal influenced by the quality of the cylinder liner surface. Its criss-cross patterned topography consists of a communicating system of grooves of different density, width, and depth, somewhere covered by folded metal, and somewhere totally interrupted and unbalanced as a result of the honing process imperfections. These features are crucial for a good liner’s function and are inspected from scanning electron microscope images by experts, which is subjective and time consuming process. Today, a fast automatic quality control is possible by using optical instruments to measure the liner’s topography, and a computer to calculate and check if the standard roughness and groove parameters are in tolerance. Therefore, combining the profile and image analysis, algorithms were developed to compute liner’s groove parameters from 3D interference measurements taken from three different types of cylinder bore surfaces of passenger cars. One of the surface types was a result of a test of an improved honing and the other two being currently in use. Then, the standard and new parameters (groove interruption, number of grooves, holes, etc) were incorporated in a characterisation tool to objectively and quickly evaluate the improvement of the liner’s quality for an updated monitoring in production.
|
|
| 29. |
|
|
| 30. |
- Dimkovski, Zlate, 1974, et al.
(författare)
-
Cylinder Liner Honed Surface Optimisation - a Manufacture-Characterisation-Function Study
- 2007
-
Ingår i: Proceedings of the 1st Swedish production symposium.
-
Konferensbidrag (refereegranskat)abstract
- In order to comply with increasingly stringent emission standards, engine manufacturers strive to reduce the oil consumption and frictional losses. One of the major contributors to it is the cylinder liner surface. Therefore, it is important to investigate what are the optimal machining parameters to manufacture liner topography with an optimal function. Numerous liners were slide honed, varying the base honing pressure and plateau honing time. The samples of the liners were measured on stylus and interferometer, and characterized by 2D and 3D parameters. The interference measurements were inputted in a flow simulation program and the mean oil flow and hydrodynamic shear stress were calculated for different nominal separations between the ring and liner. The analytical results show that a relatively low base honing pressure and longer plateau honing time give a surface with the lowest mean oil flow and the highest shear stress. A good correlation among the oil flow, shear stress, base honing pressure, Sa, Sk, Svk, and other roughness parameters was also found.
|
|
| 31. |
- Dimkovski, Zlate, 1974-, et al.
(författare)
-
Effect of the measurement size on the robustness of the assessment of the features specific for cylinder liner surfaces
- 2014
-
Ingår i: Surface Topography: Metrology and Properties. - Bristol : Institute of Physics Publishing (IOPP). - 2051-672X. ; 2:1
-
Tidskriftsartikel (refereegranskat)abstract
- The quality of the cylinder liner surface is of great importance due to its impact on the fuel/oil consumption and emissions of the internal combustion engine. A good liner function depends on the size and distribution of the deep honing grooves and the amount of the cold work material (Blechmantel) left inside the grooves after finishing. A fast evaluation of these features requires optical three-dimensional measurements with a large area and good resolution, but many interferometers used today have limited resolution when measuring larger areas. To find out how the measurement size and resolution would affect the quantification and the variation of the parameters, two objectives, 2.5 × and 10 × , were used for measuring a cylinder liner from a truck engine. The Blechmantel was of special interest as it first comes into contact with piston/rings, detaches as particles and wears the running surfaces. The 2.5 × objective showed more robust assessment than the 10 × one, manifested by a lower coefficient of variation for the parameters describing the features: Blechmantel, groove width and height, groove balance and number of grooves. This means that fewer measurements are required if a 2.5 × objective is used in production and hence the time and cost of the liner would be decreased. © 2014 IOP Publishing Ltd.
|
|
| 32. |
- Dimkovski, Zlate, 1974-, et al.
(författare)
-
Effect of the Measurement Size on the Robustness of the Assessment of the Features Specific for Cylinder Liner Surfaces
- 2013
-
Ingår i: Metrology and Properties of Engineering Surfaces, 2013. ; , s. 377-381
-
Konferensbidrag (refereegranskat)abstract
- The quality of the cylinder liner surface is of great importance due to the impact on the fuel/oil consumption and emissions of the internal combustion engines. A good liner function depends on the size and distribution of the deep honing grooves and amount of the cold work material (Blechmantel) left inside the grooves after finishing. A fast evaluation of these features requires optical 3D measurements with a larger area and good resolution, but the commercial interferometers used today are with limited resolution when measuring larger areas. To find out how the measurement size and resolution would affect the quantification and number of measurements needed for a robust assessment, two objectives, 2.5x and 10x, were used for measuring a cylinder liner from a truck engine. The Blechmantel was of a special interest as it first comes into a contact with piston/rings, detaches in particles and wears the running surfaces. The 2.5x objective showed more robust assessment than the 10x one manifested with lower number of measurements needed for the parameters describing the features: Blechmantel, groove width and height, groove balance and number of grooves.
|
|
| 33. |
- Dimkovski, Zlate, et al.
(författare)
-
Optimisation of Cylinder Liner Surface Finish by Slide Honing
- 2012
-
Ingår i: Proceedings of the Institution of mechanical engineers. Part B, journal of engineering manufacture. - London : Mechanical Engineering Publ.. - 0954-4054 .- 2041-2975. ; 226:4, s. 575-584
-
Tidskriftsartikel (refereegranskat)abstract
- Cylinder liner surface finish controls the frictional losses, oil consumption, and emissions of internal combustion engines to a large extent. In order to minimize such losses, it is important to optimize the liner surface topography by a consistent and more productive finishing process such as slide honing. This process employs diamond abrasives and has been recently introduced in the automotive industry. In this study, its potentials are explored, especially the winning combination of its key process parameters: the base honing pressure and plateau honing time that would yield an optimal liner surface finish. A number of truck engine liners were slide-honed by using different process parameters, samples of the liners were cut, and three-dimensional (3D) surface measurements were taken on a white light interferometer. Then, among others, the (deep honing) groove parameters, specific for liner surfaces, were computed from the measurements for building a large database for comparison and correlation. By simulating the contact and fluid mechanics between the measured liner topographies and a twin land oil control ring under mixed lubrication conditions, the friction mean effective pressure and oil passage rate for a range of engine speeds were calculated. These two parameters represent the liner's function associated with the engine's friction and oil consumption respectively. The results show that the lowest friction and oil flow are highly correlated with surfaces having smoother plateaus and smaller valleys, finished by using lower base honing pressure and longer plateau honing time. High correlations between the 3D roughness parameters were also found, enabling the selection and use of more stable and robust parameters in the quality control of the liner's surface finish. © IMechE 2012.
|
|
| 34. |
|
|
| 35. |
- Dimkovski, Zlate, 1974-, et al.
(författare)
-
Quantification of Blechmantel Effect on Wear of Cylinder Bore Microtopography
- 2008
-
Ingår i: Proceedings of the 13th Nordic Symposium on Tribology, Nordtrib 2008. - Tampere : Tampere University Press. - 9789521519611 ; , s. 13-
-
Konferensbidrag (refereegranskat)abstract
- The presence of cold work material (blechmantel) smeared out on cylinder liners by faulty honing is undesirable as it seals the oil-bearing honing grooves. It is also believed to correlate with increased bore wear, presumably due to its loosening and together with the carbon build-up from the piston’s top land form an increased quantity of abrasive particles. An attempt has been made to estimate the extent of removal of blechmantel for different wear regimes present at the middle and top region (near the top dead centre) of the liner surface using the unworn bottom region as a reference for comparison. A number of truck cylinder liners were axially sectioned after varying periods of engine running under similar conditions of load, engine speed and lubrication. 3D surface measurements were taken at the three regions and a range of standard parameters was extracted. Combining the profile and image analysis, an algorithm was developed to identify and quantify the blechmantel covering the grooves that is most likely to break and act as abrasive wear particles and at the same time it represents the part of blechmantel which covers the most of the surface. It was found out that a mere portion of the blechmantel from the middle and bottom section was removed, while the blechmantel from the top section was greatly removed and thereby it represents one of the possible causes for wear. Axial wear scratches more emphasized on the thrust side of the liner were observed not only through the whole stroke area, but also in the bottom region. The fact that the most of the blechmantel is not removed from the running surface of the liner (except for the very small portion of the polished areas at the dead centres), points out that the blechmantel plays only a minor role on wear of the cylinder liner surfaces.
|
|
| 36. |
- Dimkovski, Zlate, 1974, et al.
(författare)
-
Quantification of the cold worked material inside the deep honing grooves on cylider liner surfaces and its effect on wear
- 2009
-
Ingår i: Wear. - Amsterdam : Elsevier BV. - 0043-1648 .- 1873-2577. ; 267:12, s. 2235-2242
-
Tidskriftsartikel (refereegranskat)abstract
- The increased presence of cold work material on cylinder liners due to the introduction of the diamond honing is undesirable as it seats the oil-bearing honing grooves. The most of it is a smeared metal inside the deep honing grooves (blechmantel) that may break and act as abrasive wear particles increasing the bore wear. An attempt has been made to estimate the extent of removal of blechmantel for different wear regimes present at the middle and top region (near the top dead centre) of the liner surface using the least worn bottom region as a reference for comparison. A number of truck grey iron cylinder liners were axially sectioned after varying periods of engine running under similar conditions of load, engine speed and lubrication. 3D surface measurements were taken at the three regions and a range of standard parameters was extracted. Combining the profile and image analysis, an algorithm was developed to identify and quantify the blechmantel. The algorithm has successfully identified/quantified the blechmantel and can be used for automatic surface quality and process control. It was found that the amount of the blechmantel in the middle section was approximately the same (though slightly lower) as that in the bottom section, while there was a considerable dislocation and removal of blechmantel in the top section and thereby it represents one of the possible causes for wear. Axial wear scratches of different size and distribution were observed not only through the whole stroke area, but also in the bottom region. All engines and liners performed well throughout the tests, and the observed quantities of blechmantel and axial scratches are acceptable for the time being.
|
|
| 37. |
- Dimkovski, Zlate, 1974-, et al.
(författare)
-
Towards 3D Characterisation of Cylinder Liner Surfaces
- 2008
-
Ingår i: Proceedings / XII. International Colloquium on Surfaces January 28th and 29th, 2008, Chemnitz, Germany = XII. Internationales Oberflächenkolloquium. - Aachen : Shaker Verlag. - 9783832269128 ; , s. 15-24
-
Konferensbidrag (refereegranskat)abstract
- Cylinder liner surface has a direct impact on the oil consumption and frictional losses in the internal combustion engines which are in common interest to be as lower as possible. Thus, the optimisation of the liner surface, its function and manufacture is often on the agenda of the automotive industry. Since the liner surface finish is a subject of improving, there is a need of improving and facilitating of its 3D characterisation preliminary when the parameter control limits are unknown, as well as later when it is experimentally verified and the limits are better determined. For that purpose a method for quality control in 3D of cylinder liners is proposed here. A tool was developed and implemented for rating of cylinder liner surfaces, computing of 3D groove parameters (groove width, height and distance between grooves) and determination of a needed number of measurements.
|
|
| 38. |
- Downes, Marley, et al.
(författare)
-
M5X4: A Family of MXenes
- 2023
-
Ingår i: ACS Nano. - : AMER CHEMICAL SOC. - 1936-0851 .- 1936-086X. ; 17:17, s. 17158-17168
-
Tidskriftsartikel (refereegranskat)abstract
- MXenes are two-dimensional (2D) transition metal carbides, nitrides, and carbonitrides typically synthesized from layered MAX-phase precursors. With over 50 experimentally reported MXenes and a near-infinite number of possible chemistries, MXenes make up the fastest-growing family of 2D materials. They offer a wide range of properties, which can be altered by their chemistry (M, X) and the number of metal layers in the structure, ranging from two in M2XTx to five in M5X4T x . Only one M5X4 MXene, Mo4VC4, has been reported. Herein, we report the synthesis and characterization of two M(5)AX(4) mixed transition metal MAX phases, Ti2.5Ta2.5AlC4 and Ti2.675Nb2.325AlC4, and their successful topochemical transformation into Ti2.5Ta2.5C4T x and Ti2.675Nb2.325C4Tx MXenes. The resulting MXenes were delaminated into single-layer flakes, analyzed structurally, and characterized for their thermal and optical properties. This establishes a family of M(5)AX(4) MAX phases and their corresponding MXenes. These materials were experimentally produced based on guidance from theoretical predictions, leading to more exciting applications for MXenes.
|
|
| 39. |
- Ducharme, Simon, et al.
(författare)
-
Recommendations to distinguish behavioural variant frontotemporal dementia from psychiatric disorders
- 2020
-
Ingår i: Brain. - : Oxford University Press (OUP). - 0006-8950 .- 1460-2156. ; 143:6, s. 1632-1650
-
Tidskriftsartikel (refereegranskat)abstract
- The behavioural variant of frontotemporal dementia (bvFTD) is a frequent cause of early-onset dementia. The diagnosis of bvFTD remains challenging because of the limited accuracy of neuroimaging in the early disease stages and the absence of molecular biomarkers, and therefore relies predominantly on clinical assessment. BvFTD shows significant symptomatic overlap with non-degenerative primary psychiatric disorders including major depressive disorder, bipolar disorder, schizophrenia, obsessive-compulsive disorder, autism spectrum disorders and even personality disorders. To date, ∼50% of patients with bvFTD receive a prior psychiatric diagnosis, and average diagnostic delay is up to 5-6 years from symptom onset. It is also not uncommon for patients with primary psychiatric disorders to be wrongly diagnosed with bvFTD. The Neuropsychiatric International Consortium for Frontotemporal Dementia was recently established to determine the current best clinical practice and set up an international collaboration to share a common dataset for future research. The goal of the present paper was to review the existing literature on the diagnosis of bvFTD and its differential diagnosis with primary psychiatric disorders to provide consensus recommendations on the clinical assessment. A systematic literature search with a narrative review was performed to determine all bvFTD-related diagnostic evidence for the following topics: bvFTD history taking, psychiatric assessment, clinical scales, physical and neurological examination, bedside cognitive tests, neuropsychological assessment, social cognition, structural neuroimaging, functional neuroimaging, CSF and genetic testing. For each topic, responsible team members proposed a set of minimal requirements, optimal clinical recommendations, and tools requiring further research or those that should be developed. Recommendations were listed if they reached a ≥ 85% expert consensus based on an online survey among all consortium participants. New recommendations include performing at least one formal social cognition test in the standard neuropsychological battery for bvFTD. We emphasize the importance of 3D-T1 brain MRI with a standardized review protocol including validated visual atrophy rating scales, and to consider volumetric analyses if available. We clarify the role of 18F-fluorodeoxyglucose PET for the exclusion of bvFTD when normal, whereas non-specific regional metabolism abnormalities should not be over-interpreted in the case of a psychiatric differential diagnosis. We highlight the potential role of serum or CSF neurofilament light chain to differentiate bvFTD from primary psychiatric disorders. Finally, based on the increasing literature and clinical experience, the consortium determined that screening for C9orf72 mutation should be performed in all possible/probable bvFTD cases or suspected cases with strong psychiatric features.
|
|
| 40. |
- Ferrari, Raffaele, et al.
(författare)
-
Frontotemporal dementia and its subtypes: a genome-wide association study.
- 2014
-
Ingår i: Lancet Neurology. - 1474-4465. ; 13:7, s. 686-699
-
Tidskriftsartikel (refereegranskat)abstract
- Frontotemporal dementia (FTD) is a complex disorder characterised by a broad range of clinical manifestations, differential pathological signatures, and genetic variability. Mutations in three genes-MAPT, GRN, and C9orf72-have been associated with FTD. We sought to identify novel genetic risk loci associated with the disorder.
|
|
| 41. |
- Frykholm, Peter, 1961-, et al.
(författare)
-
Pre-operative fasting in children : A guideline from the European Society of Anaesthesiology and Intensive Care
- 2022
-
Ingår i: European Journal of Anaesthesiology. - : European Society of Anaesthesiology and Intensive Care. - 0265-0215 .- 1365-2346. ; 39:1, s. 4-25
-
Tidskriftsartikel (refereegranskat)abstract
- Current paediatric anaesthetic fasting guidelines have recommended conservative fasting regimes for many years and have not altered much in the last decades. Recent publications have employed more liberal fasting regimes with no evidence of increased aspiration or regurgitation rates. In this first solely paediatric European Society of Anaesthesiology and Intensive Care (ESAIC) pre-operative fasting guideline, we aim to present aggregated and evidence-based summary recommendations to assist clinicians, healthcare providers, patients and parents.We identified six main topics for the literature search: studies comparing liberal with conservative regimens; impact of food composition; impact of comorbidity; the use of gastric ultrasound as a clinical tool; validation of gastric ultrasound for gastric content and gastric emptying studies; and early postoperative feeding. The literature search was performed by a professional librarian in collaboration with the ESAIC task force.Recommendations for reducing clear fluid fasting to 1 h, reducing breast milk fasting to 3 h, and allowing early postoperative feeding were the main results, with GRADE 1C or 1B evidence. The available evidence suggests that gastric ultrasound may be useful for clinical decision-making, and that allowing a ‘light breakfast’ may be well tolerated if the intake is well controlled. More research is needed in these areas as well as evaluation of how specific patient or treatment-related factors influence gastric emptying.
|
|
| 42. |
- Galien, Sarah, et al.
(författare)
-
Point of care ultrasound screening for deep vein thrombosis in critically ill COVID-19 patients, an observational study
- 2021
-
Ingår i: Thrombosis Journal. - : Springer Science and Business Media LLC. - 1477-9560. ; 19:1
-
Tidskriftsartikel (refereegranskat)abstract
- BackgroundDeep vein thrombosis (DVT) is common in critically ill patients with Coronavirus disease 2019 (COVID-19) and may cause fatal pulmonary embolism (PE) prior to diagnosis due to subtle clinical symptoms. The aim of this study was to explore the feasibility of bedside screening for DVT in critically ill COVID-19 patients performed by physicians with limited experience of venous ultrasound. We further aimed to compare inflammation, coagulation and organ dysfunction in patients with and without venous thromboembolism (VTE).MethodsThis observational study included patients with COVID-19 admitted to the intensive care unit (ICU) of a tertiary hospital in Sweden and screened for DVT with proximal compression ultrasound of the lower extremities between April and July 2020. Screening was performed by ICU residents having received a short online education and one hands-on-session. Pathological screening ultrasound was confirmed by formal ultrasound whereas patients with negative screening underwent formal ultrasound on clinical suspicion. Clinical data, laboratory findings and follow-up were extracted from medical records.ResultsOf 90 eligible patients, 56 were screened by seven ICU residents with no (n = 5) or limited (n = 2) previous experience of DVT ultrasound who performed a median of 4 (IQR 2–19) examinations. Four (7.1%) patients had pathological screening ultrasound of which three (5.6%) were confirmed by formal ultrasound. None of the 52 patients with negative screening ultrasound were diagnosed with DVT during follow-up. Six patients were diagnosed with PE of which four prior to negative screening and two following negative and positive screening respectively. Patients with VTE (n = 8) had higher median peak D-dimer (24.0 (IQR 14.2–50.5) vs. 2.8 (IQR 1.7–7.2) mg/L, p = 0.004), mean peak C-reactive protein (363 (SD 80) vs. 285 (SD 108) mg/L, p = 0.033) and median peak plasma creatinine (288 (IQR 131–328) vs. 94 (IQR 78–131) μmol/L, p = 0.009) compared to patients without VTE (n = 48). Five patients (63%) with VTE received continuous renal replacement therapy compared to six patients (13%) without VTE (p = 0.005).ConclusionICU residents with no or limited experience could detect DVT with ultrasound in critically ill COVID-19 patients following a short education. VTE was associated with kidney dysfunction and features of hyperinflammation and hypercoagulation.Trial registrationClinicalTrials ID: NCT04316884. Registered 20 March 2020.
|
|
| 43. |
- Grossmann, Lukas, et al.
(författare)
-
Evolution of adsorption heights in the on-surface synthesis and decoupling of covalent organic networks on Ag(111) by normal-incidence X-ray standing wave
- 2022
-
Ingår i: Nanoscale Horizons. - : Royal Society of Chemistry. - 2055-6764 .- 2055-6756. ; 7:1, s. 51-62
-
Tidskriftsartikel (refereegranskat)abstract
- Structural characterization in on-surface synthesis is primarily carried out by Scanning Probe Microscopy (SPM) which provides high lateral resolution. Yet, important fresh perspectives on surface interactions and molecular conformations are gained from adsorption heights that remain largely inaccessible to SPM, but can be precisely measured with both elemental and chemical sensitivity by Normal-Incidence X-ray Standing Wave (NIXSW) analysis. Here, we study the evolution of adsorption heights in the on-surface synthesis and post-synthetic decoupling of porous covalent triazine-phenylene networks obtained from 2,4,6-tris(4-bromophenyl)-1,3,5-triazine (TBPT) precursors on Ag(111). Room temperature deposition of TBPT and mild annealing to ~150 C result in full debromination and formation of organometallic intermediates, where the monomers are linked into reticulated networks by C-Ag-C bonds. Topologically identical covalent networks comprised of triazine vertices that are interconnected by biphenyl units are obtained by a thermally activated chemical transformation of the organometallic intermediates. Exposure to iodine vapor facilitates decoupling by intercalation of an iodine monolayer between the covalent networks and the Ag(111) surface. Accordingly, Scanning Tunneling Microscopy (STM), X-ray Photoelectron Spectroscopy (XPS) and NIXSW experiments are carried out for three successive sample stages: organometallic intermediates, covalent networks directly on Ag(111) and after decoupling. NIXSW analysis facilitates the determination of adsorption heights of chemically distinct carbon species, i.e. in the phenyl and triazine rings, and also for the organometallic carbon atoms. Thereby, molecular conformations are assessed for each sample stage. The interpretation of experimental results is informed by Density Functional Theory (DFT) calculations, providing a consistent picture of adsorption heights and molecular deformations in the networks that result from the interplay between steric hindrance and surface interactions. Quantitative adsorption heights, i.e. vertical distances between adsorbates and surface, provide detailed insight into surface interactions, but are underexplored in on-surface synthesis. In particular, the direct comparison with an in situ prepared decoupled state unveils the surface influence on the network structure, and shows that iodine intercalation is a powerful decoupling strategy.
|
|
| 44. |
- Jerjes, Waseem K., et al.
(författare)
-
The future of medical diagnostics: review paper
- 2011
-
Ingår i: Head & Neck Oncology. - : Springer Science and Business Media LLC. - 1758-3284. ; 3
-
Tidskriftsartikel (refereegranskat)abstract
- While histopathology of excised tissue remains the gold standard for diagnosis, several new, non-invasive diagnostic techniques are being developed. They rely on physical and biochemical changes that precede and mirror malignant change within tissue. The basic principle involves simple optical techniques of tissue interrogation. Their accuracy, expressed as sensitivity and specificity, are reported in a number of studies suggests that they have a potential for cost effective, real-time, in situ diagnosis. We review the Third Scientific Meeting of the Head and Neck Optical Diagnostics Society held in Congress Innsbruck, Innsbruck, Austria on the 11th May 2011. For the first time the HNODS Annual Scientific Meeting was held in association with the International Photodynamic Association (IPA) and the European Platform for Photodynamic Medicine (EPPM). The aim was to enhance the interdisciplinary aspects of optical diagnostics and other photodynamic applications. The meeting included 2 sections: oral communication sessions running in parallel to the IPA programme and poster presentation sessions combined with the IPA and EPPM posters sessions.
|
|
| 45. |
- Johansson, Staffan, et al.
(författare)
-
A Novel Approach to Reduction of Frictional Losses in a Heavy-Duty Diesel Engine by Reducing the Hydrodynamic Frictional Losses
- 2017
-
Ingår i: Advances in Tribology. - New York : Hindawi Publishing Corporation. - 1687-5915 .- 1687-5923. ; 2017, s. 1-17
-
Tidskriftsartikel (refereegranskat)abstract
- An important parameter in the reduction of fuel consumption of heavy-duty diesel engines is the Power Cylinder Unit (PCU); the PCU is the single largest contributor to engine frictional losses. Much attention, from both academia and industry, has been paid to reducing the frictional losses of the PCU in the boundary and mixed lubrication regime. However, previous studies have shown that a large portion of frictional losses in the PCU occur in the hydrodynamic lubrication regime. A novel texturing design with large types of surface features was experimentally analyzed using a tribometer setup. The experimental result shows a significant reduction of friction loss for the textured surfaces. Additionally, the textured surface did not exhibit wear. On the contrary, it was shown that the textured surfaces exhibited a smaller amount of abrasive scratches on the plateaus (compared to the reference plateau honed surface) due to entrapment of wear particles within the textures. The decrease in hydrodynamic friction for the textured surfaces relates to the relative increase of oil film thickness within the textures. A tentative example is given which describes a method of decreasing hydrodynamic frictional losses in the full-scale application. © 2017 Staffan Johansson et al.
|
|
| 46. |
- Johansson, Staffan, et al.
(författare)
-
Experimental friction evaluation of cylinder liner/piston ring contact
- 2011
-
Ingår i: Wear. - Amsterdam : Elsevier. - 0043-1648 .- 1873-2577. ; 271:3-4, s. 625-633
-
Tidskriftsartikel (refereegranskat)abstract
- Fuel consumption is an extremely important parameter for the automotive industry today. Anticipated emission legislative demands in combination with a rising oil price are true motivators. In engines the piston system is the largest source of frictional losses, accounting for about 50% of the total frictional losses, thus it is important to optimize. Apart from frictional losses the piston system is a large consumer of lubricating oil, a considerable contributor to the total amount of particulate emissions (PM). New materials, coatings and high-tech machining processes that previously were considered to be too expensive and therefore only used in complex applications are today becoming more affordable. It is important to develop reliable test methods to study these new concepts. The reciprocating tribometer at Volvo Technology has been updated to better evaluate the frictional difference between material combinations/surfaces; it is possible to evaluate a number of operational parameters in each experiment. The components that were studied were a piston ring running against a cylinder liner. Friction, wear and change in surface morphology were studied in the experiments. It is shown that for the introduced DoE based tribometer test the interaction of dynamic viscosity, velocity and contact pressure can be studied within one experiment. The results show differences in friction which could be explained as the surface creating beneficial contact conditions for oil film build-up. It is also apparent that surface roughness is important regardless of material properties. To better understand the correlations between friction and surface roughness a future study should include a study of similar materials with different roughness values.
|
|
| 47. |
|
|
| 48. |
- Johansson, Staffan G., et al.
(författare)
-
Optimization of the cylinder liner surface for reduction of oil consumption
- 2005
-
Ingår i: Proceedings of the World Tribology Congress III. - 0791842029 - 9780791842027 ; , s. 559-560
-
Konferensbidrag (refereegranskat)abstract
- A decrease of oil consumption in the modern truck engine would mean decrease of particulate matter and hydrocarbon emissions. This decrease has a positive impact on the environment. One important source of oil consumption is the piston/piston-ring/liner system. One way of decreasing oil consumption is to optimize the surface topography of the liner. In this study different liner surfaces and different piston rings were investigated. The investigation shows that it is possible to decrease both the oil film thickness and the friction without sacrificing wear properties of the piston-liner system. A new surface parameter for quick wear estimation of this system is presented. Copyright © 2005 by ASME.
|
|
| 49. |
- Johansson, Staffan, et al.
(författare)
-
New cylinder liner surfaces for low oil consumption
- 2008
-
Ingår i: Tribology International. - Oxford : Elsevier. - 0301-679X .- 1879-2464. ; 41:9-10, s. 854-859
-
Tidskriftsartikel (refereegranskat)abstract
- Anticipated emission legislation and reduced fuel consumption are the main driving forces when developing new engines. Optimization of the active surfaces in the piston system is one possible way to meet the above demands. In this study the effects of surface topography and texture direction of the ring/liner contact on oil film thickness and friction were simulated and experimentally tested. "Low wear" results from the experimental wear tests with "glide honed" smooth liner surfaces supported the "low friction" simulation results. In addition a new wear volume sensitive surface roughness parameter, Rktot, based on the Abbot-Firestone bearing area curve was introduced.
|
|
| 50. |
- Johansson, Staffan, et al.
(författare)
-
Simulation and experimental analysis of the contact between oil control ring and cylinder liner in a heavy duty diesel engine
- 2013
-
Ingår i: Tribologie und Schmierungstechnik. - Renningen : Expert Verlag GmbH. - 0724-3472. ; 60:3, s. 23-33
-
Tidskriftsartikel (refereegranskat)abstract
- In heavy-duty diesel engines the piston system is the largest source of frictional losses, accounting for about 50 % of the total frictional losses. Due to the high tangential force of the oil control piston ring this component is responsible for a considerable amount of the total friction losses. The primary aim of this study was to determine the correlation between different cylinder liner surface morphology and friction; the secondary aim was to validate the simulation model using reciprocating tribometer experiments. A novel deterministic simulation approach was used to analyse the frictional interaction between oil control ring and cylinder. Multi variate analysis was used to analyse the effect of different cylinder liner surfaces on frictional outcome. Simulated results were compared to tribometer experiments. The simulation results show that a smaller honing angle decreases both hydrodynamic and boundary friction and that average level of plateau amplitude is most beneficial to decrease frictional losses. The simulation result also helps gaining insight into previous engine test result. Future work includes additional verification of the positive simulation result.
|
|
