88 research outputs found
The Double-Edges Role of Copper in the Fate of Amyloid Beta in the Presence of Anti-Oxidants
The biological fate of amyloid beta (Aβ) species is a fundamental question in Alzheimer’s disease (AD) pathogenesis. The competition between clearance and aggregation of Aβs is critical for the onset of AD. Copper has been widely considered to be an inducer of harmful crosslinking of Aβs, and an important triggering factor for the onset of AD. In this report, however, we present data to show that copper can also be an inducer of Aβ degradation in the presence of a large excess of well-known intrinsic (such as dopamine) or extrinsic (such as vitamin C) anti-oxidants. The degraded fragments were identified using SDS-Page gels, and validated via nanoLC-MS/MS. A tentative mechanism for the degradation was proposed and validated with model peptides. In addition, we performed electrophysiological analysis to investigate the synaptic functions in brain slices, and found that in the presence of a significant excess of vitamin C, Cu(II) could prevent an Aβ-induced deficit in synaptic transmission in the hippocampus. Collectively, our evidence strongly indicated that a proper combination of copper and anti-oxidants might have a positive effect on the prevention of AD. This double-edged function of copper in AD has been largely overlooked in the past. We believe that our report is very important for fully understanding the function of copper in AD pathology
Achieving high power factor and output power density in p-type half-Heuslers Nb
Improvements in thermoelectric material performance over the past two decades have largely been based on decreasing the phonon thermal conductivity. Enhancing the power factor has been less successful in comparison. In this work, a peak power factor of ∼106 μW⋅cm⁻¹⋅K⁻² is achieved by increasing the hot pressing temperature up to 1,373 K in the p-type half-Heusler Nb[subscript 0.95]Ti[subscript 0.05]FeSb. The high power factor subsequently yields a record output power density of ∼22 W⋅cm⁻² based on a single-leg device operating at between 293 K and 868 K. Such a high-output power density can be beneficial for large-scale power generation applications.United States. Department of Energy (DE-SC0001299
Visualizing the thermoelectric origin of photocurrent flow in anisotropic semimetals
Photocurrent measurements are incisive probes of crystal symmetry, electronic
band structure, and material interfaces. However, conventional scanning
photocurrent microscopy (SPCM) convolves the processes for photocurrent
generation and collection, which can obscure the intrinsic light-matter
interaction. Here, by using ac magnetometry with a nitrogen-vacancy center spin
ensemble, we demonstrate the high-sensitivity, sub-micron resolved imaging of
vector photocurrent flow. Our imaging reveals that in anisotropic semimetals
WTe2 and TaIrTe4, the photoexcited electron carriers propagate outward along
the zigzag chains and inward perpendicular to the chains. This circulating
pattern is explained by our theoretical modeling to emerge from an anisotropic
photothermoelectric effect (APTE) caused by a direction-dependent thermopower.
Through simultaneous SPCM and magnetic imaging, we directly visualize how local
APTE photocurrents stimulate long-range photocurrents at symmetry-breaking
edges and contacts. These results uniquely validate the Shockley-Ramo process
for photocurrent collection in gapless materials and identify the overlooked
APTE as the primary origin of robust photocurrents in anisotropic semimetal
devices. Our work highlights quantum-enabled photocurrent flow microscopy as a
clarifying perspective for complex optoelectronic phenomena.Comment: 16 pages, 4 main figures, 5 supporting figure
Causal link between gut microbiota and four types of pancreatitis: a genetic association and bidirectional Mendelian randomization study
BackgroundA number of recent observational studies have indicated a correlation between the constitution of gut microbiota and the incidence of pancreatitis. Notwithstanding, observational studies are unreliable for inferring causality because of their susceptibility to confounding, bias, and reverse causality, the causal relationship between specific gut microbiota and pancreatitis is still unclear. Therefore, our study aimed to investigate the causal relationship between gut microbiota and four types of pancreatitis.MethodsAn investigative undertaking encompassing a genome-wide association study (GWAS) comprising 18,340 participants was undertaken with the aim of discerning genetic instrumental variables that exhibit associations with gut microbiota, The aggregated statistical data pertaining to acute pancreatitis (AP), alcohol-induced AP (AAP), chronic pancreatitis (CP), and alcohol-induced CP (ACP) were acquired from the FinnGen Consortium. The two-sample bidirectional Mendelian randomization (MR) approach was utilized. Utilizing the Inverse-Variance Weighted (IVW) technique as the cornerstone of our primary analysis. The Bonferroni analysis was used to correct for multiple testing, In addition, a number of sensitivity analysis methodologies, comprising the MR-Egger intercept test, the Cochran’s Q test, MR polymorphism residual and outlier (MR-PRESSO) test, and the leave-one-out test, were performed to evaluate the robustness of our findings.ResultsA total of 28 intestinal microflora were ascertained to exhibit significant associations with diverse outcomes of pancreatitis. Among them, Class Melainabacteria (OR = 1.801, 95% CI: 1.288–2.519, p = 0.008) has a strong causality with ACP after the Bonferroni-corrected test, in order to assess potential reverse causation effects, we used four types of pancreatitis as the exposure variable and scrutinized its impact on gut microbiota as the outcome variable, this analysis revealed associations between pancreatitis and 30 distinct types of gut microflora. The implementation of Cochran’s Q test revealed a lack of substantial heterogeneity among the various single nucleotide polymorphisms (SNP).ConclusionOur first systematic Mendelian randomization analysis provides evidence that multiple gut microbiota taxa may be causally associated with four types of pancreatitis disease. This discovery may contribute significant biomarkers conducive to the preliminary, non-invasive identification of Pancreatitis. Additionally, it could present viable targets for potential therapeutic interventions in the disease’s treatment
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Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study
Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat
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Correction to: Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study
The original version of this article unfortunately contained a mistake
Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study
Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat
Performance Aspiration in Meritocratic Systems: Evidence of How Academic Titles Affect the Performance of Universities
The study of academic title differences in universities helps to promote researchers’ enthusiasm and is critical to the efficiency of university scientific research. This study examines the impact of academic title differences on the research efficiency of universities and explores its mechanism. Based on the perspective of production types, the scientific and technological innovation achievements of universities are divided into academic output and economic output. By using the stochastic frontier model, this paper evaluates the influence of different academic titles on the academic and economic production efficiency of scientific research innovation in universities. The research results show that academic output efficiency increases over time, while the economic output efficiency decreases over time. Researchers with associate professor titles are more efficient in academic research production, and researchers with lecturer titles are more efficient in economic research production. Regional economy is positively correlated with the economic output of universities and negatively correlated with academic output. The production and development of academic and economic research in different regions are not coordinated
Identification of Relevant Biomarkers in Mercury Exposed Clam Venerupis philippinarum.
This study assessed the impact of four different concentrations (2.5, 5, 7.5, 10 μg/L) of mercury exposure on Manila clam Venerupis philippinarum based on the dynamic characteristics of antioxidant related enzymes including superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), acid phosphatase (ACP), alkaline phosphatase (ALP), total glutathione content, and malondialdehyde (MDA) content at 24 h and 48 h post exposure.
The results showed that hemocyte SOD activity was inhibited while GR hemocyte activity significantly increased in the 2.5 μg/L group after 24 h. Hemocyte ALP activity and (GSH) content were also elevated at the 7.5 μg/L and 10 μg/L groups when exposed for 24 h, respectively. SOD activity, GR activity, ALP activity and GSH content in the hemocytes were relatively sensitive to different concentrations of mercuric mercury (Hg2+), suggesting that they may act as potential biomarkers in assessing environmental mercury exposure on Venerupis philippinarum. At different levels of exposure, antioxidant parameters showed differing responses in gill tissue, but no biomarkers were discovered in the samples examined. We found that hemocytes are more suitable biomarkers than proteins in gill tissue. Some hemocyte biomarkers are promising candidates for monitoring mercury pollution in marine clams
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