316 research outputs found

    Future changes in urban drainage pressure caused by precipitation extremes in 285 cities across China based on CMIP6 models

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    High pressure on urban drainage systems caused by extreme precipitation events would lead to an increase risk of urban floods. Across China, future changes in urban drainage pressure (UDP) and its response to global-scale climate mitigation and local adaptation, have seldom been studied. Here, based on climate projections from the Coupled Model Intercomparison Project Phase 6 (CMIP6), we assessed UDP changes from 2020 to 2099 under different scenarios in 285 cities across China. Under the shared socioeconomic pathway (SSP) 5–8.5 scenario, 30% larger increase of UDP relative to the baseline level (1985–2014), would occur in 22.80% and 79.65% cities over 2020–2049 and 2050–2099, respectively. Under climate mitigation (SSP2–4.5 scenario), UDP in northern China would decrease by 10–30% over 2020–2049. On this basis, 10% enhancement of underlying surface retention capacity (LID10% scenario) would reduce UDP by more than 10% particularly in northern and northeastern China (23.51% cities). Pipe enlargement adaptation (Pipe10% scenario) would benefit UDP mainly in eastern China (46.31% cities), by postponing the first decade with 30% larger pressure relative to the baseline level by 1-3 decades.</p

    Aristolochic acid induces acute kidney injury through ferroptosis

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    Aristolochic acid (AA)-induced acute kidney injury (AKI) presents with progressive decline in renal function and rapid progression to end-stage renal disease. Among the multiple mechanisms identified in AKI, ferroptosis has been shown to be involved in various forms of AKI. But few studies have elucidated the role of ferroptosis in AA-induced AKI. In this study, we investigated the role of ferroptosis in AA-induced acute renal tubular injury in vivo and in vitro. Mice with acute aristolochic acid nephropathy showed increased malondialdehyde levels, aggravated lipid peroxidation, decreased superoxide dismutase activity, and glutathione depletion. The expression of glutathione peroxidase 4 was decreased and the expression of acyl-CoA synthetase long-chain family member 4 was increased. Inhibition of ferroptosis by ferrostatin-1 significantly improved the renal function, reduced histopathological lesions, partially alleviated lipid peroxidation, and restored the antioxidant capacity. In vitro studies also revealed that AA significantly reduced cell viability, induced reactive oxygen species production, increased intracellular iron level and decreased ferroptosis-related protein expression. Inhibition of ferroptosis significantly increased cell viability and attenuated AA-induced renal tubular epithelial cell injury. It is suggested that ferroptosis plays an important role in AA-induced acute tubular injury. And inhibition of ferroptosis may exert renoprotective effects possibly by preventing lipid peroxidation, restoring the antioxidant activity or regulating iron metabolism

    Association of Lean Body Mass Index and Peritoneal Protein Clearance in Peritoneal Dialysis Patients

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    Background/Aims: The relationship between peritoneal protein clearance (PPCl) and nutritional status in peritoneal dialysis (PD) population have not been clarified. This study aims to investigate the relationship between PPCl and nutritional status in PD population. Methods: Prevalent PD patients were enrolled in the cross-sectional survey in a single center from April to November 2013. The total amount of protein loss in the dialysate was calculated. PPCl reflects the individual differences of peritoneal protein loss, and is calculated by the formula, that PPCl (ml/day)=24-h dialysate protein loss / (albumin/0.4783). Nutritional status measured by lean body mass index (LBMI) was assessed by multi-frequency bioelectrical impedance analysis (BIA). Results: Totally 351 PD patients (55% male, 17.1% with diabetes, mean age 47.7±14.3 years) were included. The median PPC l was 58 ml/day. Patients were divided into four groups for comparison according to the PPC quartiles. Compared with lower PPCl quartiles, patients with higher PPCl had higher body mass index (BMI) (P&#x3c; 0.001), body surface area (BSA) (P &#x3c; 0 .001), LBMI (P&#x3c;0.001), 4-hour D/P creatinine ratio (P&#x3c; 0.001), and lower residual renal CCl (P&#x3c;0.001). Compared with conventional body index (BMI and BSA) in ROC analysis, LBMI (area under curve: 0.71, 95% confidence interval [CI]: 0.66-0.77) had better performance in predicting higher PPCl. After adjustment in logistic regression models, each 1 kg/m2 increase of LBMI (odd ratio[OR] =1.37; 95% CI: 1.17-1.60), each 0.1 increase of 4-hour D/P creatinine ratio (OR =1.47; 95% CI: 1.11-1.93), and every 1 L/week/1.73m2 decrease of residual renal CCl (OR =0.98; 95% CI: 0.96-0.99) were independently associated with higher PPCl (&#x3e; 58 ml/day). Conclusion: Higher LBMI was independently associated with higher , indicating that better nutritional status dominates peritoneal protein metabolism in PD patients

    SY18ΔL60L: a new recombinant live attenuated African swine fever virus with protection against homologous challenge

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    IntroductionAfrican swine fever (ASF) is an acute and highly contagious disease and its pathogen, the African swine fever virus (ASFV), threatens the global pig industry. At present, management of ASF epidemic mainly relies on biological prevention and control methods. Moreover, due to the large genome of ASFV, only half of its genes have been characterized in terms of function.MethodsHere, we evaluated a previously uncharacterized viral gene, L60L. To assess the function of this gene, we constructed a deletion strain (SY18ΔL60L) by knocking out the L60L gene of the SY18 strain. To evaluate the growth characteristics and safety of the SY18ΔL60L, experiments were conducted on primary macrophages and pigs, respectively.ResultsThe results revealed that the growth trend of the recombinant strain was slower than that of the parent strain in vitro. Additionally, 3/5 (60%) pigs intramuscularly immunized with a 105 50% tissue culture infectious dose (TCID50) of SY18ΔL60L survived the 21-day observation period. The surviving pigs were able to protect against the homologous lethal strain SY18 and survive. Importantly, there were no obvious clinical symptoms or viremia.DiscussionThese results suggest that L60L could serve as a virulence- and replication-related gene. Moreover, the SY18ΔL60L strain represents a new recombinant live-attenuated ASFV that can be employed in the development of additional candidate vaccine strains and in the elucidation of the mechanisms associated with ASF infection

    Investigating the L-Glu-NMDA receptor-H2S-NMDA receptor pathway that regulates gastric function in rats’ nucleus ambiguus

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    BackgroundIn previous investigations, we explored the regulation of gastric function by hydrogen sulfide (H2S) and L-glutamate (L-Glu) injections in the nucleus ambiguus (NA). We also determined that both H2S and L-Glu have roles to play in the physiological activities of the body, and that NA is an important nucleus for receiving visceral sensations. The purpose of this study was to explore the potential pathway link between L-Glu and H2S, resulting in the regulation of gastric function.MethodsPhysiological saline (PS), L-glutamate (L-Glu, 2 nmol), NaHS (2 nmol), D-2-amino-5-phopho-novalerate (D-AP5, 2 nmol) + L-Glu (2 nmol), aminooxyacetic acid (AOAA, 2 nmol) + L-Glu (2 nmol), D-AP5 (2 nmol) + NaHS (2 nmol) were injected into the NA. A balloon was inserted into the stomach to observe gastric pressure and for recording the changes of gastric smooth muscle contraction curve. The gastric fluid was collected by esophageal perfusion and for recording the change of gastric pH value.ResultsInjecting L-Glu in NA was found to significantly inhibit gastric motility and promote gastric acid secretion in rats (p &lt; 0.01). On the other hand, injecting the PS, pre-injection N-methyl-D-aspartate (NMDA) receptor blocker D-AP5, cystathionine beta-synthase (CBS) inhibitor AOAA and re-injection L-Glu did not result in significant changes (p &gt; 0.05). The same injection NaHS significantly inhibit gastric motility and promote gastric acid secretion in rats (p &lt; 0.01), but is eliminated by injection D-AP5 (p &gt; 0.05).ConclusionThe results indicate that both exogenous L-Glu and H2S injected in NA regulate gastric motility and gastric acid secretion through NMDA receptors. This suggests that NA has an L-Glu-NMDA receptor-CBS-H2S pathway that regulates gastric function

    The relationship between daytime napping and glycemic control in people with type 2 diabetes

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    AimTo examine the association between napping characteristics and glycemic control in people with type 2 diabetes.DesignThis study used a cross-sectional design.MethodsA convenience sample of people with type 2 diabetes (N=226) were included. Glycemic control was indicated by HbA1c which was measured by A1C NowÂź+. Napping characteristics including napping frequency, duration, timing, and type were measured by validated questionnaires. Other variables, such as insomnia, cognitive impairment, and depression were measured by the Insomnia Severity Index, Montreal Cognitive Assessment, and Patient Health Questionnaire-9, respectively. Multivariate linear regression analyses were performed.ResultsThe sample consisted of 122 women (54.0%), with a median age of 67 years. Their median HbA1c was 6.8%. No significant relationship was found between napping frequency and HbA1c. Among nappers, after controlling for covariates, long napping duration (≄60 min) and morning napping were both associated with poorer glycemic control. Compared with appetitive napping, restorative napping was associated with better glycemic control.ConclusionDaytime napping (e.g., duration and type) is an important modifiable factor for glycemic control in people with type 2 diabetes. This study provides new insights into the relationship between napping and glucose management among people with diabetes

    Low alpha-defensin gene copy number increases the risk for IgA nephropathy and renal dysfunction

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    IgA nephropathy (IgAN) is the most common primary glomerulonephritis worldwide. Although a major source of genetic variation, copy number variations (CNVs) and their involvement in disease development have not been well studied. Here, we performed association analysis of the DEFA1A3 CNV locus in two independent IgAN cohorts of Southern Chinese Han (total1189 cases and 1187 controls). We discovered three independent copy number associations within the locus: DEFA1A3 (P=3.99×10-9, OR=0.88), DEFA3 (P=6.55×10-5, OR=0.82) and a noncoding deletion variant (211bp) (P=3.50×10-16, OR=0.75) (OR per copy, fixed-effects meta-analysis). While showing strong association with increased risk for IgAN (P=9.56×10-20), low total copy numbers of the three variants also showed significant association with renal dysfunction in patients with IgAN (P=0.03, HR=3.69, after controlling for the effects of known prognostic factors) as well as high serum IgA1 (P=0.02) and a high proportion of galactose-deficient IgA1 (P=0.03). For replication, we confirmed the associations of DEFA1A3 (P=4.42×10-4, OR=0.82) and DEFA3 copy numbers (P=4.30×10-3, OR=0.74) with IgAN in a Caucasian cohort (531 cases and 198 controls) and found the 211bp variant to be much rarer in Caucasians. Interestingly, we also observed an association of the 211bp copy number with membranous nephropathy (P=1.11×10-7, OR=0.74 in 493 Chinese cases and 500 matched controls), but not with diabetic kidney disease (in 806 Chinese cases and 786 matched controls). By explaining 4.96% of disease risk and influencing the renal dysfunction in IgAN, the DEFA1A3 CNV locus is a potential candidate for therapeutic target and prognostic marker development

    Aristolochic Acid I Induced Autophagy Extenuates Cell Apoptosis via ERK 1/2 Pathway in Renal Tubular Epithelial Cells

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    Autophagy is a lysosomal degradation pathway that is essential for cell survival and tissue homeostasis. However, limited information is available about autophagy in aristolochic acid (AA) nephropathy. In this study, we investigated the role of autophagy and related signaling pathway during progression of AAI-induced injury to renal tubular epithelial cells (NRK52E cells). The results showed that autophagy in NRK52E cells was detected as early as 3–6 hrs after low dose of AAI (10 ”M) exposure as indicated by an up-regulated expression of LC3-II and Beclin 1 proteins. The appearance of AAI-induced punctated staining of autophagosome-associated LC3-II upon GFP-LC3 transfection in NRK52E cells provided further evidence for autophagy. However, cell apoptosis was not detected until 12 hrs after AAI treatment. Blockade of autophagy with Wortmannin or 3-Methyladenine (two inhibitors of phosphoinositede 3-kinases) or small-interfering RNA knockdown of Beclin 1 or Atg7 sensitized the tubular cells to apoptosis. Treatment of NRK52E cells with AAI caused a time-dependent increase in extracellular signal-regulated kinase 1 and 2 (ERK1/2) activity, but not c-Jun N-terminal kinase (JNK) and p38. Pharmacological inhibition of ERK1/2 phosphorylation with U0126 resulted in a decreased AAI-induced autophagy that was accompanied by an increased apoptosis. Taken together, our study demonstrated for the first time that autophagy occurred earlier than apoptosis during AAI-induced tubular epithelial cell injury. Autophagy induced by AAI via ERK1/2 pathway might attenuate apoptosis, which may provide a protective mechanism for cell survival under AAI-induced pathological condition

    Real-time GDP nowcasting in New Zealand : an ensemble machine learning approach : a thesis presented for the degree of Master of Philosophy, School of Natural and Computational Sciences, Massey University, New Zealand

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    Gross Domestic Product (GDP) measures the monetary value of all ïŹnal goods and services that are produced in a region during a period of time. For most countries, GDP is released a limited number of times a year and often with a lag. Understanding the current economic situation, instead of ïŹgures quarters ago, is of vital importance for both policy and private entrepreneurs. It is crucial to create a live GDP predictor that could Nowcast current GDP growth rate in the period of government statistics release delay. The Econometric approach for GDP Nowcasting has dominated the forecasting area for many years. However, most of the traditional econometric models could only incorporate a small handful of variables with a linear model structure, which could not meet the requirement of the “big data” era for a better model prediction ability with a large amount of unbalanced variables. With the improvement of computation ability and the increment of high frequency variables, data-driven approaches like Machine Learning Methods have been applied into Nowcasting area. It does not only show a stronger forecasting ability in handling large number of predictors but also present a superior robustness for non-linear data structure. In this research, an Ensemble Method constructed by several Machine Learning Methods have been generated to provide more timely available GDP ïŹgures in the period of government statistics release delay. Having integrated an input dataset with data from multiple data sources such as public statistical websites, Reserve Bank of NZ and Stats NZ, our cooperators New Zealand Transport Agency (NZTA) and PayMark, this study is conducted by ïŹrst applying diïŹ€erent Machine Learning methods such as Lightgbm, Xgboost, Support Vector Machine, K- Nearest Neighbors, Ridge Regression, Lasso, Adaboost models. Then these algorithms are combined to generate an Ensemble Model with the assistance of an averaging method, which weights each model individually based on its historical prediction accuracy. The result of the ïŹnal Ensemble Model is compared with the most commonly used benchmark ARIMA model and Random Walk model in terms of Mean Square Error (MSE) and Median Absolute Error(MAE) value. Statistical tests, such as Friedman Test and Wilcoxon Signed-Rank Test, are employed to check the signiïŹcance of model superiority. The results indicate that the Ensemble Model signiïŹcantly outperforms individual Machine Learning algorithm and Random Walk model in forecasting accuracy. When compared with the ARIMA model, it shows slightly better prediction ability with more fore-sights especially in a ïŹ‚uctuating environment
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