2,765 research outputs found
Power-Electronics-Based Mission Profile Emulation and Test for Electric Machine Drive System:Concepts, Features, and Challenges
Unraveling the Oxidation Mechanism of Formic Acid on Pd(111) Electrode: Implication from pH Effect and H/D Kinetic Isotope Effect
The pH effect and H/D kinetic isotope effect (KIE) of formic acid oxidation reaction (FAOR) on Pd(111) have been systematically investigated by cyclic voltammetry. In addition, the pH effect of acetate adsorption on Pd(111) is also studied to have a deep understanding of the role of adsorbates on Pd(111) during the FAOR process. The results clearly show: (1) In solutions with a fixed concentration of acetic acid, the onset potential of acetate desorption is almost unchanged on the reversible hydrogen electrode (RHE) scale with the increase of pH when the pH is lower than the pKa of acetic acid. However, when the pH is higher than the pKa of acetic acid, the onset potential of acetate desorption shifts positively with a slope of ca. 20 mV per pH unit; (2) In solutions with pH less than 6, the maximum coverage of acetate adsorbed on the Pd(111) electrode is about 0.26 ML; (3) In acidic solutions, FAOR on Pd(111) has obvious pH effect in the potential range of current increasing on SHE scale. After correcting the pHs-induced shift, the onset potential of FAOR shifts negatively by ca. 90 mV per pH unit. However, the pH effect disappears in the potential range after the peak; (4) In alkaline solutions, the onset potential of FAOR is influenced by OHad; (5) The H/D KIE factor of FAOR on Pd(111) is ca. 5 in the pH range of 1–14. Two possible mechanisms trying to explain these results have been proposed. In one, COOadλ– is the active intermediate and the formation of this intermediate is the rate-determining step (RDS), whereas, in the second one, monodentate adsorbed formate (HCOOm) is the active intermediate and its dissociation on the surface is the RDS. The simulated results with both mechanisms are compared with the experimental results and discussed critically.This work was financially supported by the National Natural Science Foundation of China (nos. 22172151 and 22372154). E.H. and J.M.F. acknowledge financial support from Ministerio de Ciencia, Innovación y Universidades (Project PID2022-137350NB-I00). Zhen Wei acknowledges support from the China Scholarship Council (award number 202106340060)
Hawking radiation as tunneling and the unified first law of thermodynamics at the apparent horizon in the FRW universe
Relations between the tunneling rate and the unified first law of
thermodynamics at the apparent horizon of the FRW universe are investigated.
The tunneling rate arises as a consequence of the unified first law of
thermodynamics in such a dynamical system. The analysis shows obviously how the
tunneling is intimately connected with the unified first law of thermodynamics
through the principle of conservation of energy.Comment: Latex, 9 pages, no figur
MEMD-ABSA: A Multi-Element Multi-Domain Dataset for Aspect-Based Sentiment Analysis
Aspect-based sentiment analysis is a long-standing research interest in the
field of opinion mining, and in recent years, researchers have gradually
shifted their focus from simple ABSA subtasks to end-to-end multi-element ABSA
tasks. However, the datasets currently used in the research are limited to
individual elements of specific tasks, usually focusing on in-domain settings,
ignoring implicit aspects and opinions, and with a small data scale. To address
these issues, we propose a large-scale Multi-Element Multi-Domain dataset
(MEMD) that covers the four elements across five domains, including nearly
20,000 review sentences and 30,000 quadruples annotated with explicit and
implicit aspects and opinions for ABSA research. Meanwhile, we evaluate
generative and non-generative baselines on multiple ABSA subtasks under the
open domain setting, and the results show that open domain ABSA as well as
mining implicit aspects and opinions remain ongoing challenges to be addressed.
The datasets are publicly released at \url{https://github.com/NUSTM/MEMD-ABSA}
Using Bioinformatics Approach to Explore the Pharmacological Mechanisms of Multiple Ingredients in Shuang-Huang-Lian
Due to the proved clinical efficacy, Shuang-Huang-Lian (SHL) has
developed a variety of dosage forms. However, the in-depth
research on targets and pharmacological mechanisms of SHL
preparations was scarce. In the presented study, the
bioinformatics approaches were adopted to integrate relevant data
and biological information. As a result, a PPI network was built
and the common topological parameters were characterized. The
results suggested that the PPI network of SHL exhibited a
scale-free property and modular architecture. The drug target
network of SHL was structured with 21 functional modules.
According to certain modules and pharmacological effects
distribution, an antitumor effect and potential drug targets were
predicted. A biological network which contained 26 subnetworks was
constructed to elucidate the antipneumonia mechanism of SHL. We
also extracted the subnetwork to explicitly display the pathway
where one effective component acts on the pneumonia related
targets. In conclusions, a bioinformatics approach was established
for exploring the drug targets, pharmacological activity
distribution, effective components of SHL, and its mechanism of
antipneumonia. Above all, we identified the effective components
and disclosed the mechanism of SHL from the view of system
Pyrosequencing of Haliotis diversicolor Transcriptomes: Insights into Early Developmental Molluscan Gene Expression
National Natural Science Foundation of China [40976093]; National Basic Research Program of China (973) [2010CB126403]; Hi-Tech Research and Development (863) Program of China [2012AA10A412]Background: The abalone Haliotis diversicolor is a good model for study of the settlement and metamorphosis, which are widespread marine ecological phenomena. However, information on the global gene backgrounds and gene expression profiles for the early development of abalones is lacking. Methodology/Principal Findings: In this study, eight non-normalized and multiplex barcode-labeled transcriptomes were sequenced using a 454 GS system to cover the early developmental stages of the abalone H. diversicolor. The assembly generated 35,415 unigenes, of which 7,566 were assigned GO terms. A global gene expression profile containing 636 scaffolds/contigs was constructed and was proven reliable using qPCR evaluation. It indicated that there may be existing dramatic phase transitions. Bioprocesses were proposed, including the 'lock system' in mature eggs, the collagen shells of the trochophore larvae and the development of chambered extracellular matrix (ECM) structures within the earliest postlarvae. Conclusion: This study globally details the first 454 sequencing data for larval stages of H. diversicolor. A basic analysis of the larval transcriptomes and cluster of the gene expression profile indicates that each stage possesses a batch of specific genes that are indispensable during embryonic development, especially during the two-cell, trochophore and early postlarval stages. These data will provide a fundamental resource for future physiological works on abalones, revealing the mechanisms of settlement and metamorphosis at the molecular level
Exploring the complex relationship between gut microbiota and risk of colorectal neoplasia using bidirectional Mendelian Randomization analysis
Background: Human gut microbiome has complex relation-ships with the host, contributing to metabolism, immunity, and carcinogenesis. Methods: Summary-level data for gut microbiota and metabo-lites were obtained from MiBioGen, FINRISK and human meta-bolome consortia. Summary-level data for colorectal cancer were derived from a genome-wide association study meta-analysis. In forward Mendelian randomization (MR), we employed genetic instrumental variables (IV) for 24 gut microbiota taxa and six bacterial metabolites to examine their causal relationship with colorectal cancer. We also used a lenient threshold for nine apriori gut microbiota taxa as secondary analyses. In reverse MR, we explored association between genetic liability to colorectal neoplasia and abundance of microbiota studied above using 95, 19, and 7 IVs for colorectal cancer, adenoma, and polyps, respectively. Results: Forward MR did not find evidence indicating causal relationship between any of the gut microbiota taxa or six bacterial metabolites tested and colorectal cancer risk. However, reverse MR supported genetic liability to colorectal adenomas was causally related with increased abundance of two taxa: Gammaproteobacteria (b = 0.027, which represents a 0.027 increase in log-transformed relative abundance values of Gam-maproteobacteria for per one-unit increase in log OR of adenoma risk; P = 7.06x10-8), Enterobacteriaceae (b = 0.023, P = 1.29x10-5). Conclusions: We find genetic liability to colorectal neoplasia may be associated with abundance of certain microbiota taxa. It is more likely that subset of colorectal cancer genetic liability variants changes gut biology by influencing both gut microbiota and colo-rectal cancer risk.Impact: This study highlights the need of future complemen-tary studies to explore causal mechanisms linking both host genetic variation with gut microbiome and colorectal cancer susceptibility
Randomized controlled trial: neostigmine for intra-abdominal hypertension in acute pancreatitis
BACKGROUND: Intra-abdominal hypertension (IAH) in acute pancreatitis (AP) is associated with deterioration in organ function. This trial aimed to assess the efficacy of neostigmine for IAH in patients with AP. METHODS: In this single-center, randomized trial, consenting patients with IAH within 2 weeks of AP onset received conventional treatment for 24 h. Patients with sustained intra-abdominal pressure (IAP) ≥ 12 mmHg were randomized to receive intramuscular neostigmine (1 mg every 12 h increased to every 8 h or every 6 h, depending on response) or continue conventional treatment for 7 days. The primary outcome was the percent change of IAP at 24 h after randomization. RESULTS: A total of 80 patients were recruited to neostigmine (n = 40) or conventional treatment (n = 40). There was no significant difference in baseline parameters. The rate of decrease in IAP was significantly faster in the neostigmine group compared to the conventional group by 24 h (median with 25th–75th percentile: −18.7% [− 28.4 to − 4.7%] vs. − 5.4% [− 18.0% to 0], P = 0.017). This effect was more pronounced in patients with baseline IAP ≥ 15 mmHg (P = 0.018). Per-protocol analysis confirmed these results (P = 0.03). Stool volume was consistently higher in the neostigmine group during the 7-day observational period (all P < 0.05). Other secondary outcomes were not significantly different between neostigmine and conventional treatment groups. CONCLUSION: Neostigmine reduced IAP and promoted defecation in patients with AP and IAH. These results warrant a larger, placebo-controlled, double-blind phase III trial. Trial registration Clinical Trial No: NCT02543658 (registered August /27, 2015). SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13054-022-03922-4
Time Distribution of the Onset of Chest Pain in Subjects with Acute ST-Elevation Myocardial Infarction: An Eight-Year, Single-Center Study in China
Objective: The objective of this study was to explore the time distribution patterns of the onset of chest pain in subjects with acute ST-elevation myocardial infarction in a Chinese population. Methods: A total of 1467 patients with acute ST-elevation myocardial infarction were enrolled from 2003 to 2010. The hourly, daily, monthly, seasonal and day-of-week fluctuations in the prevalence of acute ST-elevation myocardial infarction were analyzed. Results: A peak was found between the morning hours of 07:31 and 08:30. A second peak was observed between 14:31 and 15:30, and a third peak was found between 23:31 and 00:30 (p,0.001). The monthly maximum was recorded in November and the minimum was in April (p,0.001). The number of daily cases was greatest in autumn and lowest in the spring (p = 0.001). Day-of-the-week variations of ST-elevation acute myocardial infarction were not found, except in patients more than 75-years-old. Conclusions: Periodic variations in the frequency of ST-elevation acute myocardial infarction in Chinese patients showed significant differences with regard to diurnal, monthly and seasonal patterns. The exact mechanisms underlying thes
Biomarkers for Early Diagnostic of Mild Cognitive Impairment in Type-2 Diabetes Patients: A Multicentre, Retrospective, Nested Case–Control Study
AbstractBackgroundBoth type 2 diabetes mellitus (T2DM) and Alzheimer's disease (AD) are common age-associated disorders and T2DM patients show an increased risk to suffer from AD, however, there is currently no marker to identify who in T2DM populations will develop AD. Since glycogen synthase kinase-3β (GSK-3β) activity, ApoE genotypes and olfactory function are involved in both T2DM and AD pathogenesis, we investigate whether alterations of these factors can identify cognitive impairment in T2DM patients.MethodsThe cognitive ability was evaluated using Minimum Mental State Examination (MMSE) and Clinical Dementia Rating (CDR), and the mild cognitive impairment (MCI) was diagnosed by Petersen's criteria. GSK-3β activity in platelet, ApoE genotypes in leucocytes and the olfactory function were detected by Western/dot blotting, the amplification refractory mutation system (ARMS) PCR and the Connecticut Chemosensory Clinical Research Center (CCCRC) test, respectively. The odds ratio (OR) and 95% confidence intervals (95% CI) of the biomarkers for MCI diagnosis were calculated by logistic regression. The diagnostic capability of the biomarkers was evaluated by receiver operating characteristics (ROC) analyses.FindingsWe recruited 694 T2DM patients from Jan. 2012 to May. 2015 in 5 hospitals (Wuhan), and 646 of them met the inclusion criteria and were included in this study. 345 patients in 2 hospitals were assigned to the training set, and 301 patients in another 3 hospitals assigned to the validation set. Patients in each set were randomly divided into two groups: T2DM without MCI (termed T2DM-nMCI) or with MCI (termed T2DM-MCI). There were no significant differences for sex, T2DM years, hypertension, hyperlipidemia, coronary disease, complications, insulin treatment, HbA1c, ApoE ε2, ApoE ε3, tGSK3β and pS9GSK3β between the two groups. Compared with the T2DM-nMCI group, T2DM-MCI group showed lower MMSE score with older age, ApoE ε4 allele, higher olfactory score and higher rGSK-3β (ratio of total GSK-3β to Ser9-phosphorylated GSK-3β) in the training set and the validation set. The OR values of age, ApoE ε4 gene, olfactory score and rGSK-3β were 1.09, 2.09, 1.51, 10.08 in the training set, and 1.06, 2.67, 1.47, 7.19 in the validation set, respectively. The diagnostic accuracy of age, ApoE ε4 gene, olfactory score and rGSK-3β were 0.76, 0.72, 0.66, 0.79 in the training set, and 0.70, 0.68, 0.73, 0.79 in the validation set, respectively. These four combined biomarkers had the area under the curve (AUC) of 82% and 86%, diagnostic accuracy of 83% and 81% in the training set and the validation set, respectively.InterpretationAging, activation of peripheral circulating GSK-3β, expression of ApoE ε4 and increase of olfactory score are diagnostic for the mild cognitive impairment in T2DM patients, and combination of these biomarkers can improve the diagnostic accuracy
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