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"Ma, Jing"
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الحجر السماوي : قصص قصيرة /
مجموعة مترادفات قصصية للأديب الصيني «ما تشونغ جينغ» ضمن سلسلة إبداعات أدب الأقليات الصينية، وتضم قصصا قصيرة لعادات الأقليات الصينية، وسلوكيات العائلات في المناسبات الدينية والاحتفالات الأخرى المختلفة، وتتباين فيها الشخصيات والزمان والمكان، لتضع القارئ أمام رسم أدبي يشرح حياة الأقليات الصينية المليئة بالتناص.
Book
Biaxially strained PtPb/Pt core/shell nanoplate boosts oxygen reduction catalysis
Compressive surface strains have been necessary to boost oxygen reduction reaction (ORR) activity in core/shell M/platinum (Pt) catalysts (where M can be nickel, cobalt, or iron). We report on a class of platinum-lead/platinum (PtPb/Pt) core/shell nanoplate catalysts that exhibit large biaxial strains. The stable Pt (110) facets of the nanoplates have high ORR specific and mass activities that reach 7.8 milliampere (mA) per centimeter squared and 4.3 ampere per milligram of platinum at 0.9 volts versus the reversible hydrogen electrode (RHE), respectively. Density functional theory calculations reveal that the edge-Pt and top (bottom)-Pt (110) facets undergo large tensile strains that help optimize the Pt-O bond strength. The intermetallic core and uniform four layers of Pt shell of the PtPb/Pt nanoplates appear to underlie the high endurance of these catalysts, which can undergo 50,000 voltage cycles with negligible activity decay and no apparent structure and composition changes.
Journal Article
Clinical characteristics of novel coronavirus cases in tertiary hospitals in Hubei Province
The 2019 novel coronavirus (2019-nCoV) causing an outbreak of pneumonia in Wuhan, Hubei province of China was isolated in January 2020. This study aims to investigate its epidemiologic history, and analyze the clinical characteristics, treatment regimens, and prognosis of patients infected with 2019-nCoV during this outbreak.
Clinical data from 137 2019-nCoV-infected patients admitted to the respiratory departments of nine tertiary hospitals in Hubei province from December 30, 2019 to January 24, 2020 were retrospectively collected, including general status, clinical manifestations, laboratory test results, imaging characteristics, and treatment regimens.
None of the 137 patients (61 males, 76 females, aged 20-83 years, median age 57 years) had a definite history of exposure to Huanan Seafood Wholesale Market. Major initial symptoms included fever (112/137, 81.8%), coughing (66/137, 48.2%), and muscle pain or fatigue (44/137, 32.1%), with other, less typical initial symptoms observed at low frequency, including heart palpitations, diarrhea, and headache. Nearly 80% of the patients had normal or decreased white blood cell counts, and 72.3% (99/137) had lymphocytopenia. Lung involvement was present in all cases, with most chest computed tomography scans showing lesions in multiple lung lobes, some of which were dense; ground-glass opacity co-existed with consolidation shadows or cord-like shadows. Given the lack of effective drugs, treatment focused on symptomatic and respiratory support. Immunoglobulin G was delivered to some critically ill patients according to their conditions. Systemic corticosteroid treatment did not show significant benefits. Notably, early respiratory support facilitated disease recovery and improved prognosis. The risk of death was primarily associated with age, underlying chronic diseases, and median interval from the appearance of initial symptoms to dyspnea.
The majority of patients with 2019-nCoV pneumonia present with fever as the first symptom, and most of them still showed typical manifestations of viral pneumonia on chest imaging. Middle-aged and elderly patients with underlying comorbidities are susceptible to respiratory failure and may have a poorer prognosis.
Journal Article
Mitochondrial phosphatase PGAM5 modulates cellular senescence by regulating mitochondrial dynamics
Mitochondria undergo dynamic fusion/fission, biogenesis and mitophagy in response to stimuli or stresses. Disruption of mitochondrial homeostasis could lead to cell senescence, although the underlying mechanism remains unclear. We show that deletion of mitochondrial phosphatase PGAM5 leads to accelerated retinal pigment epithelial (RPE) senescence in vitro and in vivo. Mechanistically, PGAM5 is required for mitochondrial fission through dephosphorylating DRP1.
PGAM5
deletion leads to increased mitochondrial fusion and decreased mitochondrial turnover. As results, cellular ATP and reactive oxygen species (ROS) levels are elevated, mTOR and IRF/IFN-β signaling pathways are enhanced, leading to cellular senescence. Overexpression of Drp1 K38A or S637A mutant phenocopies or rescues mTOR activation and senescence in
PGAM5
−
/−
cells, respectively. Young but not aging
Pgam5
−/−
mice are resistant to sodium iodate-induced RPE cell death. Our studies establish a link between defective mitochondrial fission, cellular senescence and age-dependent oxidative stress response, which have implications in age-related diseases.
Mitochondria are a hub that can direct cellular outcomes in response to stress. Here, the authors show that mitochondrial phosphatase PGAM5 has a role in mitochondrial turnover and regulation of cellular senescence by altering organellar dynamics via fission regulator Drp1.
Journal Article
60 °C solution synthesis of atomically dispersed cobalt electrocatalyst with superior performance
Temperature can govern morphologies, structures and properties of products from synthesis in solution. A reaction in solution at low temperature may result in different materials than at higher temperature due to thermodynamics and kinetics of nuclei formation. Here, we report a low-temperature solution synthesis of atomically dispersed cobalt in a catalyst with superior performance. By using a water/alcohol mixed solvent with low freezing point, liquid-phase reduction of a cobalt precursor with hydrazine hydrate is realized at −60 °C. A higher energy barrier and a sluggish nucleation rate are achieved to suppress nuclei formation; thus atomically dispersed cobalt is successfully obtained in a catalyst for oxygen reduction with electrochemical performance superior to that of a Pt/C catalyst. Furthermore, the atomically dispersed cobalt catalyst is applied in a microbial fuel cell to obtain a high maximum power density (2550 ± 60 mW m
−2
) and no current drop upon operation for 820 h.
Rapid nucleation and growth hinder the formation of atomically dispersed metals on solid supports in solution. Here the authors report a low-temperature solution-phase synthesis for isolated cobalt atoms on nitrogen-doped carbon, with electrocatalytic activity for oxygen reduction in a microbial fuel cell.
Journal Article
The value of five scoring systems in predicting the prognosis of patients with sepsis-associated acute respiratory failure
Our study aimed to identify the optimal scoring system for predicting the prognosis of patients with sepsis-associated acute respiratory failure (SA-ARF). All data were taken from the fourth version of the Markets in Intensive Care Medicine (MIMIC-IV) database. Independent risk factors for death in hospitals were confirmed by regression analysis. The predictive value of the five scoring systems was evaluated by receiving operating characteristic (ROC) curves. Kaplan‒Meier curves showed the impact of acute physiology score III (APSIII) on survival and prognosis in patients with SA-ARF. Decision curve analysis (DCA) identified a scoring system with the highest net clinical benefit. ROC curve analysis showed that APS III (AUC: 0.755, 95% Cl 0.714–0.768) and Logical Organ Dysfunction System (LODS) (AUC: 0.731, 95% Cl 0.717–0.7745) were better than Simplified Acute Physiology Score II (SAPS II) (AUC: 0.727, 95% CI 0.713–0.741), Oxford Acute Severity of Illness Score (OASIS) (AUC: 0.706, 95% CI 0.691–0.720) and Sequential Organ Failure Assessment (SOFA) (AUC: 0.606, 95% CI 0.590–0.621) in assessing in-hospital mortality. Kaplan‒Meier survival analysis patients in the high-APS III score group had a considerably poorer median survival time. The DCA curve showed that APS III may provide better clinical benefits for patients. We demonstrated that the APS III score is an excellent predictor of in-hospital mortality.
Journal Article
Tissue Distribution of Berberine and Its Metabolites after Oral Administration in Rats
Berberine (BBR) has been confirmed to have multiple bioactivities in clinic, such as cholesterol-lowering, anti-diabetes, cardiovascular protection and anti- inflammation. However, BBR's plasma level is very low; it cannot explain its pharmacological effects in patients. We consider that the in vivo distribution of BBR as well as of its bioactive metabolites might provide part of the explanation for this question. In this study, liquid chromatography coupled to ion trap time-of-flight mass spectrometry (LC/MS(n)-IT-TOF) as well as liquid chromatography that coupled with tandem mass spectrometry (LC-MS/MS) was used for the study of tissue distribution and pharmacokinetics of BBR in rats after oral administration (200 mg/kg). The results indicated that BBR was quickly distributed in the liver, kidneys, muscle, lungs, brain, heart, pancreas and fat in a descending order of its amount. The pharmacokinetic profile indicated that BBR's level in most of studied tissues was higher (or much higher) than that in plasma 4 h after administration. BBR remained relatively stable in the tissues like liver, heart, brain, muscle, pancreas etc. Organ distribution of BBR's metabolites was also investigated paralleled with that of BBR. Thalifendine (M1), berberrubine (M2) and jatrorrhizine (M4), which the metabolites with moderate bioactivity, were easily detected in organs like the liver and kidney. For instance, M1, M2 and M4 were the major metabolites in the liver, among which the percentage of M2 was up to 65.1%; the level of AUC (0-t) (area under the concentration-time curve) for BBR or the metabolites in the liver was 10-fold or 30-fold higher than that in plasma, respectively. In summary, the organ concentration of BBR (as well as its bioactive metabolites) was higher than its concentration in the blood after oral administration. It might explain BBR's pharmacological effects on human diseases in clinic.
Journal Article
Systemic activation of NLRP3 inflammasome and plasma α-synuclein levels are correlated with motor severity and progression in Parkinson’s disease
Background
Emerging evidence indicates that inflammasome-induced inflammation plays a crucial role in the pathogenesis of Parkinson’s disease (PD). Several proteins including α-synuclein trigger the activation of NLRP3 inflammasome. However, few studies examined whether inflammasomes are activated in the periphery of PD patients and their possible value in the diagnosis or tracking of the progress of PD. The aim of this study was to determine the association between inflammasome-induced inflammation and clinical features in PD.
Methods
There were a total of 67 participants, including 43 patients with PD and 24 controls, in the study. Participants received a complete evaluation of motor and non-motor symptoms, including Hoehn and Yahr (H-Y) staging scale. Blood samples were collected from all participants. The protein and mRNA expression levels of inflammasomes subtypes and components in peripheral blood mononuclear cells (PBMCs) were determined using western blotting and RT-qPCR. We applied Meso Scale Discovery (MSD) immunoassay to measure the plasma levels of IL-1β and α-synuclein.
Results
We observed increased gene expression of NLRP3, ASC, and caspase-1 in PBMCs, and increased protein levels of NLRP3, caspase-1, and IL-1β in PD patients. Plasma levels of IL-1β were significantly higher in patients with PD compared with controls and have a positive correlation with H-Y stage and UPDRS part III scores. Furthermore, plasma α-synuclein levels were also increased in PD patients and have a positive correlation with both UPDRS part III scores and plasma IL-1β levels.
Conclusions
Our data demonstrated that the NLRP3 inflammasome is activated in the PBMCs from PD patients. The related inflammatory cytokine IL-1β and total α-synuclein in plasma were increased in PD patients than controls, and both of them presented a positive correlation with motor severity in patients with PD. Furthermore, plasma α-synuclein levels have a positive correlation with IL-1β levels in PD patients. All these findings suggested that the NLRP3 inflammasome activation-related cytokine IL-1β and α-synuclein could serve as non-invasive biomarkers to monitor the severity and progression of PD in regard to motor function.
Journal Article