103 research outputs found

    Designing Optimal Perovskite Structure for High Ionic Conduction.

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    Solid-oxide fuel/electrolyzer cells are limited by a dearth of electrolyte materials with low ohmic loss and an incomplete understanding of the structure-property relationships that would enable the rational design of better materials. Here, using epitaxial thin-film growth, synchrotron radiation, impedance spectroscopy, and density-functional theory, the impact of structural parameters (i.e., unit-cell volume and octahedral rotations) on ionic conductivity is delineated in La0.9 Sr0.1 Ga0.95 Mg0.05 O3- δ . As compared to the zero-strain state, compressive strain reduces the unit-cell volume while maintaining large octahedral rotations, resulting in a strong reduction of ionic conductivity, while tensile strain increases the unit-cell volume while quenching octahedral rotations, resulting in a negligible effect on the ionic conductivity. Calculations reveal that larger unit-cell volumes and octahedral rotations decrease migration barriers and create low-energy migration pathways, respectively. The desired combination of large unit-cell volume and octahedral rotations is normally contraindicated, but through the creation of superlattice structures both expanded unit-cell volume and large octahedral rotations are experimentally realized, which result in an enhancement of the ionic conductivity. All told, the potential to tune ionic conductivity with structure alone by a factor of ≈2.5 at around 600 °C is observed, which sheds new light on the rational design of ion-conducting perovskite electrolytes

    Raw Garlic Consumption and Risk of Liver Cancer: A Population-Based Case-Control Study in Eastern China.

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    Although the major risk factors for liver cancer have been established, preventive factors for liver cancer have not been fully explored. We evaluated the association between raw garlic consumption and liver cancer in a large population-based case-control study in Eastern China. The study was conducted in Jiangsu, China, from 2003 to 2010. A total of 2011 incident liver cancer cases and 7933 randomly selected population-controls were interviewed. Epidemiological data including raw garlic intake and other exposures were collected, and serum markers of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection were assayed. Overall, eating raw garlic twice or more per week was inversely associated with liver cancer, with an adjusted odds ratio (aOR) of 0.77 (95% confidence interval (CI): 0.62-0.96) compared to those ingesting no raw garlic or less than twice per week. In stratified analyses, high intake of raw garlic was inversely associated with liver cancer among Hepatitis B surface antigen (HBsAg) negative individuals, frequent alcohol drinkers, those having history of eating mold-contaminated food or drinking raw water, and those without family history of liver cancer. Marginal interactions on an additive scale were observed between low raw garlic intake and HBsAg positivity (attributable proportion due to interaction (AP) = 0.31, 95% CI: -0.01-0.62) and heavy alcohol drinking (AP = 0.28, 95% CI: 0.00-0.57). Raw garlic consumption is inversely associated with liver cancer. Such an association shed some light on the potential etiologic role of garlic intake on liver cancer, which in turn might provide a possible dietary intervention to reduce liver cancer in Chinese population

    Assessment of the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire for use in patients after neck dissection for head and neck cancer

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    BackgroundIn this cross‐sectional study, the sensibility, test‐retest reliability, and validity of the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire were assessed in patients who underwent neck dissection.MethodsSensibility was assessed with a questionnaire. Test‐retest reliability was performed with completion of the DASH questionnaire 2 weeks after initial completion; validity, by evaluating differences in scores between patients undergoing different types of neck dissections and correlating DASH scores with Neck Dissection Impairment Index (NDII) scores.ResultsThe DASH questionnaire met sensibility criteria. For test‐retest reliability analysis, the intraclass coefficient was 0.91. The DASH questionnaire showed differences between patients who underwent accessory nerve‐sacrifice and nerve‐sparing neck dissection. DASH questionnaire scores strongly correlated with NDII scores (r = ‐0.86).ConclusionAlthough this study provides preliminary data on some psychometric properties of the DASH questionnaire in patients who have undergone a neck dissection, further assessment of responsiveness and other properties are required. © 2014 Wiley Periodicals, Inc. Head Neck 37: 234‐242, 2015Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/110617/1/hed23593.pd

    Chinese medicine, Qijudihuang pill, mediates cholesterol metabolism and regulates gut microbiota in high-fat diet-fed mice, implications for age related macular degeneration

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    Background: Traditional Chinese Medicines have been used for thousands of years but without any sound empirical basis. One such preparation is the Qijudihuang pill (QP), a mixture of eight herbs, that has been used in China for the treatment of various conditions including age-related macular degeneration (AMD), the most common cause of blindness in the aged population. In order to explain the mechanism behind the effect of QP, we used an AMD model of high-fat diet (HFD) fed mice to investigate cholesterol homeostasis, oxidative stress, inflammation and gut microbiota.Methods: Mice were randomly divided into three groups, one group was fed withcontrol diet (CD), the other two groups were fed with high-fat-diet (HFD). OneHFD group was treated with QP, both CD and the other HFD groups were treatedwith vehicles. Tissue samples were collected after the treatment. Cholesterollevels in retina, retinal pigment epithelium (RPE), liver and serum weredetermined using a commercial kit. The expression of enzymes involved incholesterol metabolism, inflammation and oxidative stress was measured withqRT-PCR. Gut microbiota was analyzed using 16S rRNA sequencing.Results: In the majority of the lipid determinations, analytes were elevated by HFD but thiswas reversed by QP. Cholesterol metabolism including the enzymes of bile acid (BA) formationwas suppressed by HFD but again thiswas reversed by QP. BAs play amajor role in signaling between host andmicrobiome and this is disrupted by HFD resulting in major changes in the composition of colonic bacterial communities. Associated with these changes are predictions of the metabolic pathway complexity and abundance of individual pathways. These concerned substrate breakdowns, energy production and the biosynthesis of proinflammatory factors but were changed back to control characteristics by QP.Conclusion: We propose that the ability of QP to reverse these HFD-inducedeffects is related to mechanisms acting to lower cholesterol level, oxidative stress and inflammation, and to modulate gut microbiota

    Older persons’ and their caregivers’ perspectives and experiences of research participation with impaired decision-making capacity: A scoping review

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    Background and Objectives: Human research ethics statements support equitable inclusion of diverse groups. Yet older people are under-represented in clinical research, especially those with impaired decision-making capacity. The aim of this study was to identify perspectives and experiences of older persons and their caregivers of research participation with impaired decision-making capacity. Research Design and Methods: Scoping review of literature and online sources in January-February 2019 (updated June 2020) according to Joanna Briggs Institute methodology and PRISMA Extension for Scoping Reviews. English-language peer-reviewed research articles and Australian online narratives were included. Data were tabulated and narratively synthesized. Results: From 4171 database records and 93 online resources, 22 articles (2000-2019, 82% United States, 16 first authors) and one YouTube webinar (2018) were initially included; updated searches yielded an additional article (2020) and YouTube webinar (2020). Studies were heterogeneous in terminology, methods and foci, with hypothetical scenarios, quantitative analyses and examination of proxy consent predominating. Participants (n=7331) were older persons (71%), caregivers of older persons with dementia/cognitive impairment (23%) and older persons with dementia/cognitive impairment (6%). Synthesis identified two themes: willingness to participate and decision-making approaches. Discussion and Implications: Research participation by older persons with dementia may be optimized through reducing risks and burdens and increasing benefits for participants, greater consumer input into study development, and shared and supported decision-making. Older persons’ and caregivers’ perspectives and experiences of research participation with impaired decision-making capacity require investigation in a greater range of countries and conditions other than dementia, and dissemination through more varied media

    When and where did India and Asia collide?

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    Timing of the collision between India and Asia is the key boundary condition in all models for the evolution of the Himalaya-Tibetan orogenic system. Thus it profoundly affects the interpretation of the rates of a multitude of associated geological processes ranging from Tibetan Plateau uplift through continental extrusion across eastern Asia, as well as our understanding of global climate change during the Cenozoic. Although an abrupt slowdown in the rate of convergence between India and Asia around 55 Ma is widely regarded as indicating the beginning of the collision, most of the effects attributed to this major tectonic episode do not occur until more than 20 Ma later. Refined estimates of the relative positions of India and Asia indicate that they were not close enough to one another to have collided at 55 Ma. On the basis of new field evidence from Tibet and a reassessment of published data we suggest that continent-continent collision began around the Eocene/Oligocene boundary (∼34 Ma) and propose an alternative explanation for events at 55 Ma. Copyright 2007 by the American Geophysical Union.published_or_final_versio

    Hospital admission and emergency care attendance risk for SARS-CoV-2 delta (B.1.617.2) compared with alpha (B.1.1.7) variants of concern: a cohort study

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    Background: The SARS-CoV-2 delta (B.1.617.2) variant was first detected in England in March, 2021. It has since rapidly become the predominant lineage, owing to high transmissibility. It is suspected that the delta variant is associated with more severe disease than the previously dominant alpha (B.1.1.7) variant. We aimed to characterise the severity of the delta variant compared with the alpha variant by determining the relative risk of hospital attendance outcomes. Methods: This cohort study was done among all patients with COVID-19 in England between March 29 and May 23, 2021, who were identified as being infected with either the alpha or delta SARS-CoV-2 variant through whole-genome sequencing. Individual-level data on these patients were linked to routine health-care datasets on vaccination, emergency care attendance, hospital admission, and mortality (data from Public Health England's Second Generation Surveillance System and COVID-19-associated deaths dataset; the National Immunisation Management System; and NHS Digital Secondary Uses Services and Emergency Care Data Set). The risk for hospital admission and emergency care attendance were compared between patients with sequencing-confirmed delta and alpha variants for the whole cohort and by vaccination status subgroups. Stratified Cox regression was used to adjust for age, sex, ethnicity, deprivation, recent international travel, area of residence, calendar week, and vaccination status. Findings: Individual-level data on 43 338 COVID-19-positive patients (8682 with the delta variant, 34 656 with the alpha variant; median age 31 years [IQR 17–43]) were included in our analysis. 196 (2·3%) patients with the delta variant versus 764 (2·2%) patients with the alpha variant were admitted to hospital within 14 days after the specimen was taken (adjusted hazard ratio [HR] 2·26 [95% CI 1·32–3·89]). 498 (5·7%) patients with the delta variant versus 1448 (4·2%) patients with the alpha variant were admitted to hospital or attended emergency care within 14 days (adjusted HR 1·45 [1·08–1·95]). Most patients were unvaccinated (32 078 [74·0%] across both groups). The HRs for vaccinated patients with the delta variant versus the alpha variant (adjusted HR for hospital admission 1·94 [95% CI 0·47–8·05] and for hospital admission or emergency care attendance 1·58 [0·69–3·61]) were similar to the HRs for unvaccinated patients (2·32 [1·29–4·16] and 1·43 [1·04–1·97]; p=0·82 for both) but the precision for the vaccinated subgroup was low. Interpretation: This large national study found a higher hospital admission or emergency care attendance risk for patients with COVID-19 infected with the delta variant compared with the alpha variant. Results suggest that outbreaks of the delta variant in unvaccinated populations might lead to a greater burden on health-care services than the alpha variant. Funding: Medical Research Council; UK Research and Innovation; Department of Health and Social Care; and National Institute for Health Research

    Changes in symptomatology, reinfection, and transmissibility associated with the SARS-CoV-2 variant B.1.1.7: an ecological study

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    Background The SARS-CoV-2 variant B.1.1.7 was first identified in December, 2020, in England. We aimed to investigate whether increases in the proportion of infections with this variant are associated with differences in symptoms or disease course, reinfection rates, or transmissibility. Methods We did an ecological study to examine the association between the regional proportion of infections with the SARS-CoV-2 B.1.1.7 variant and reported symptoms, disease course, rates of reinfection, and transmissibility. Data on types and duration of symptoms were obtained from longitudinal reports from users of the COVID Symptom Study app who reported a positive test for COVID-19 between Sept 28 and Dec 27, 2020 (during which the prevalence of B.1.1.7 increased most notably in parts of the UK). From this dataset, we also estimated the frequency of possible reinfection, defined as the presence of two reported positive tests separated by more than 90 days with a period of reporting no symptoms for more than 7 days before the second positive test. The proportion of SARS-CoV-2 infections with the B.1.1.7 variant across the UK was estimated with use of genomic data from the COVID-19 Genomics UK Consortium and data from Public Health England on spike-gene target failure (a non-specific indicator of the B.1.1.7 variant) in community cases in England. We used linear regression to examine the association between reported symptoms and proportion of B.1.1.7. We assessed the Spearman correlation between the proportion of B.1.1.7 cases and number of reinfections over time, and between the number of positive tests and reinfections. We estimated incidence for B.1.1.7 and previous variants, and compared the effective reproduction number, Rt, for the two incidence estimates. Findings From Sept 28 to Dec 27, 2020, positive COVID-19 tests were reported by 36 920 COVID Symptom Study app users whose region was known and who reported as healthy on app sign-up. We found no changes in reported symptoms or disease duration associated with B.1.1.7. For the same period, possible reinfections were identified in 249 (0·7% [95% CI 0·6–0·8]) of 36 509 app users who reported a positive swab test before Oct 1, 2020, but there was no evidence that the frequency of reinfections was higher for the B.1.1.7 variant than for pre-existing variants. Reinfection occurrences were more positively correlated with the overall regional rise in cases (Spearman correlation 0·56–0·69 for South East, London, and East of England) than with the regional increase in the proportion of infections with the B.1.1.7 variant (Spearman correlation 0·38–0·56 in the same regions), suggesting B.1.1.7 does not substantially alter the risk of reinfection. We found a multiplicative increase in the Rt of B.1.1.7 by a factor of 1·35 (95% CI 1·02–1·69) relative to pre-existing variants. However, Rt fell below 1 during regional and national lockdowns, even in regions with high proportions of infections with the B.1.1.7 variant. Interpretation The lack of change in symptoms identified in this study indicates that existing testing and surveillance infrastructure do not need to change specifically for the B.1.1.7 variant. In addition, given that there was no apparent increase in the reinfection rate, vaccines are likely to remain effective against the B.1.1.7 variant. Funding Zoe Global, Department of Health (UK), Wellcome Trust, Engineering and Physical Sciences Research Council (UK), National Institute for Health Research (UK), Medical Research Council (UK), Alzheimer's Society
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