Landslides are one of the most common catastrophic mass flows in mountainous areas. The occurrence of fragmentation leads to the evolution of the integrity and stiffness of the sliding mass. The ...changes in internal composition caused by basal erosion and entrainment make the dynamic evolution of landslides more complex. To consider these complex processes, physics-based dynamic models are often used to analyze the dynamic characteristics of landslides. However, the proprietary assumptions of dynamic models often limit their application to complex events. A single dynamic model is often not competent for the analysis of landslides with evolving dynamic characteristics. In this study, two dynamic models are effectively integrated according to the evolving characteristics of the landslide. The common effects of basal erosion and entrainment are also considered. The maximum sliding velocity, accumulation range, and erosion depth characteristics of this integrated dynamic model are more consistent with the field than those of the single dynamic model. Under the terrain conditions of this study, within a few seconds of the triggering stage, if the occurrence of disintegration is advanced by 2 s, the maximum impact area will increase by about 3.1% to 4.1%, and the maximum kinetic energy will increase by more than 20%. Simulation results indicate that the changes in the integrity of the landslide body significantly affect the evolution of subsequent landslide dynamic characteristics.
Hand, foot, and mouth disease (HFMD) is an infectious disease caused by human enterovirus 71 (EV71), coxsackievirus A16 (CVA16) and other enteroviruses. It is of interest that other enteroviruses ...associated with HFMD in Jinan have been rarely reported. The aim of the present study is to detect and characterize the circulating serotypes of non-EV71 and non-CVA16 enteroviruses associated with HFMD in Jinan city, Shandong province, China. A total of 400 specimens were collected from clinically diagnosed HFMD cases in Jinan from January 2009 to June 2013. All specimens were infected with non-EV71 and non-CVA16 enteroviruses previously confirmed by RT-PCR or real-time PCR according to the protocols at that time. The GeXP-based multiplex RT-PCR assay (GeXP assay) was performed to investigate the pathogen spectrum of 15 enteroviruses (coxsackieviruses A4, A5, A6, A9, A10, A16; coxsackieviruses B1, B3, B5; Echoviruses 6, 7, 11, 13, 19 and EV71) infections associated with HMFD. For GeXP assay negative samples, reverse transcription nested PCR (nested RT-PCR) based on the 5' -untranslated region (5'- UTR) sequence and phylogenetic analysis were conducted to further explore the etiology of multiple enteroviruses. The results showed that a total of twenty serotypes of enteroviruses (including EV71 and CVA16) were identified by GeXP assay and nested RT-PCR. The most circulating twelve serotypes of enteroviruses with HFMD in Jinan from 2009 to June 2013 were EV71, CVA16, CVA10, CVA6, CVA12, CVA2, Echo3, CVA4, CVA9, CVB1, CVB3 and Echo6. CVA10 and CVA6 were the most prevalent pathogens other than EV71 and CVA16 in Jinan and their most prevalent seasons were spring and summer, and a slight increase was observed in autumn and early winter. It should be noted that mixed-infections were identified by GeXP assay and the phylogenetic tree clearly discriminated the multiple pathogens associated with HFMD. Our results thus demonstrate that there was a clear lack of a reliable testing method for EV71 and CVA16 and multiple non-EV71 and non-CVA16 enteroviruses associated with HFMD were present in Jinan. The GeXP assay combined with nested RT-PCR based on 5'-UTR region could meet the need for the national surveillance of multiple enteroviruses or the investigation of epidemic outbreaks triggered by enteroviruses in the future.
In order to increase the stalling margin of a compressor under different inlet conditions, especially under inlet distortion conditions, a new coupled casing processing structure is proposed in this ...paper. The new structure combines the characteristics of traditional circumferential slot and axial slot casing treatments. First, based on numerical simulation results of the simplified calculation model, a control variable method is used to design the coupled casing treatment and an effective casing treatment scheme (CCTF) is obtained. Then, experiments and multistage full-channel numerical simulations are used to study the effect of CCTF on the compressor performance under uniform and distorted inlet conditions. The stability expansion effect and the mechanism of the structure under inlet distortion conditions are analyzed in detail. The results show that the jet in CCTF obstructs the main flow and causes additional mixing loss, but inhibits the expansion and crushing of the leakage vortex, thus increasing the stall margin of the compressor. Under near-stall conditions, the tail-circumferential groove provides about 64.8% of the flow rate, which improves the stability expansion capability of the casing treatment. When there is distortion at the inlet, CCTF can still effectively improve the stability.
A novel quinoline-degrading strain, named K4, was isolated from activated sludge of a coking wastewater treatment plant and identified as Brevundimonas sp. on the basis of its 16s rDNA gene sequence ...analysis. Its optimum temperature and pH for quinoline degradation were 30 °C and pH 9.0, respectively, and during the biodegradation process, at 100 mg/L initial quinoline concentration, an inoculation amount of 8% (OD600 of 0.23) was the optimal strain concentration. In addition, the kinetics of free K4 strains for quinoline degradation showed that it followed a zero-order equation. Furthermore, compared with free K4 strains, immobilized K4 strains' potential for quinoline degradation was investigated by adding both of them into SBR reactors for actual coking wastewater treatment on operation over 15 days. The results showed that bioaugmentation by both free and immobilized K4 strains enhanced quinoline removal efficiency, and especially, the latter could reach its stable removal after a shorter accommodation period, with 94.8% of mean quinoline removal efficiency.
In order to accurately and quickly predict the failure probability of gears with multiple failure modes, a novel reliability analysis methodology based on the mixed Copula (MCopula) function model is ...proposed to deal with the complex correlation among different failure functions. Firstly, we construct a novel MCopula model based on three famous Copula functions: Gumbel Copula, Clayton Copula, and Frank Copula functions. Secondly, we use and improve the particle swarm optimization (PSO) method to optimally calculate the weight coefficients in the proposed MCopula model. Thirdly, the maximum likelihood estimation (MLE) method is adopted to estimate related parameters in the proposed MCopula model. Finally, we verify the proposed reliability analysis methodology with a standard life-prediction case of a strut system and a practical life-problem case of a gear pair system. Comparison results of both cases show that, by using the proposed methodology, the failure probability of a gear pair system with multiple failure correlations can be quickly calculated through a small number of samples and can be estimated as accurately as that by the Monte Carlo scheme. Consequently, our proposed novel methodology successfully analyzes the reliability problems for a gear pair system with multiple failure modes. The proposed methodology can be further applied to solve the reliability problem for other machine parts.
Objective
A recessive biallelic repeat expansion, (AAGGG)exp, in the RFC1 gene has been reported to be a frequent cause of late‐onset ataxia. For cerebellar ataxia, neuropathy, and vestibular ...areflexia syndrome (CANVAS), the recessive biallelic (AAGGG)exp genotype was present in ~92% of cases. This study aimed to examine whether the pentanucleotide repeat (PNR) was related to multiple system atrophy (MSA), which shares a spectrum of symptoms with CANVAS.
Methods
In this study, we screened the pathogenic (AAGGG)exp repeat and 5 other PNRs in 104 Chinese sporadic adult‐onset ataxia of unknown aetiology (SAOA) patients, 282 MSA patients, and 203 unaffected individuals. Multiple molecular genetic tests were used, including long‐range polymerase chain reaction (PCR), repeat‐primed PCR (RP‐PCR), Sanger sequencing, and Southern blot. Comprehensive clinical assessments were conducted, including neurological examination, neuroimaging, nerve electrophysiology, and examination of vestibular function.
Results
We identified biallelic (AAGGG)exp in 1 SAOA patient and 3 MSA patients. Additionally, 1 MSA patient had the (AAGGG)exp/(AAAGG)exp genotype with uncertain pathogenicity. We also described the carrier frequency for different PNRs in our cohorts. Furthermore, we summarized the distinct phenotypes of affected patients, suggesting that biallelic (AAGGG)exp in RFC1 could be associated with MSA and should be screened routinely in the MSA diagnostic workflow.
Interpretation
Our results expanded the clinical phenotypic spectrum of RFC1‐related disorders and raised the possibility that MSA might share the same genetic background as CANVAS, which is crucial for re‐evaluating the current CANVAS and MSA diagnostic criteria. ANN NEUROL 2020;88:1132–1143
The multivariate statistical method such as principal component analysis based on linear dimension reduction and kernel principal component analysis based on nonlinear dimension reduction as the ...modified principal component analysis method are commonly used. Because of the diversity and correlation of robotic global performance indexes, the two multivariate statistical methods principal component analysis and kernel principal component analysis methods can be used, respectively, to comprehensively evaluate the global performance of PUMA560 robot with different dimensions. When using the kernel principal component analysis method, the kernel function and parameters directly have an effect on the result of comprehensive performance evaluation. Because kernel principal component analysis with polynomial kernel function is time-consuming and inefficient, a new kernel function based on similarity degree is proposed for the big sample data. The new kernel function is proved according to Mercer’s theorem. By comparing different dimension reduction effects of principal component analysis method, the kernel principal component analysis method with polynomial kernel function, and the kernel principal component analysis method with the new kernel function, the kernel principal component analysis method with the new kernel function could deal more effectively with the nonlinear relationship among indexes, and its calculation result is more reasonable for containing more comprehensive information. The simulation shows that the kernel principal component analysis method with the new kernel function has the advantage of low time consuming, good real-time performance, and good ability of generalization.
Our goal was to create a simple risk-prediction model for renal function decline after cardiac surgery to help focus renal follow-up efforts on patients most likely to benefit.
This single-center ...retrospective cohort study enrolled 24 904 patients who underwent cardiac surgery from 2012 to 2019 at Fuwai Hospital, Beijing, China. An estimated glomerular filtration rate (eGFR) reduction of ≥30% 3 months after surgery was considered evidence of renal function decline. Relative to patients with eGFR 60 to 89 mL/min per 1.73 m
(4.5% 531/11733), those with eGFR ≥90 mL/min per 1.73 m
(10.9% 1200/11042) had a higher risk of renal function decline, whereas those with eGFR ≤59 mL/min per 1.73 m
(5.8% 124/2129) did not. Each eGFR stratum had a different strongest contributor to renal function decline: increased baseline eGFR levels for patients with eGFR ≥90 mL/min per 1.73 m
, transfusion of any blood type for patients with eGFR 60 to 89 mL/min per 1.73 m
, and no recovery of renal function at discharge for patients with eGFR ≤59 mL/min per 1.73 m
. Different nomograms were established for the different eGFR strata, which yielded a corrected C-index value of 0.752 for eGFR ≥90 mL/min per 1.73 m
, 0.725 for eGFR 60-89 mL/min per 1.73 m
and 0.791 for eGFR ≤59 mL/min per 1.73 m
.
Predictors of renal function decline over the follow-up showed marked differences across the eGFR strata. The nomograms incorporated a small number of variables that are readily available in the routine cardiac surgical setting and can be used to predict renal function decline in patients stratified by baseline eGFR.
Open repair of thoracoabdominal aortic aneurysm (TAAA) was characterized by significant risk of postoperative mortality and morbidity. The aim of this study was to determine the perioperative ...predictors of early and long-term mortality in patients undergoing open repair of TAAA. Besides, the postoperative outcomes in patients with open repair of TAAA were described.
This is a single-center retrospective study, and 146 patients with open repair of TAAA from January 4, 2011, to November 22, 2018 was involved. Categorical variables were analyzed by the Chi-square test or Fisher's exact test, and continuous variables were analyzed by the independent sample t-test and the WilCoxon rank-sum test. Multivariate Logistic regression and Cox regression were applied to identify the predictors of 30-day and long-term mortality, respectively. The Kaplan Meier curves were used to illustrate survival with the Log-rank test.
The 30-day mortality was 9.59% (n = 14). Older than 50 years, the intraoperative volume of red blood cell (RBC) and epinephrine use were independently associated with postoperative 30-day mortality in open repair of TAAA. Long-term mortality was 17.12% (n = 25) (median of 3.5 years (IQR = 2-5 years) of follow-up). Prior open thoracoabdominal aortic aneurysm (TAAA) repair, aortic cross-clamping (ACC) time, intraoperative volume of RBC and use of epinephrine were independently correlated with long-term mortality.
Identifying perioperative risk factors of early and long-term mortaliy is crucial for surgeons. Intraoperative volume of RBC and use of epinephrine were predictors of both early and long-term mortality. In addition, patients of advanced age, prior open repair of TAAA and prolonged ACC time should be paid more attention.
During the operation of an active clearance control (ACC) system of a turbine, the aerodynamic performance of the intake grille indirectly influences its control. To improve the performance, an ...aerodynamic optimization method is proposed, consisting of parameterization, an optimization algorithm, and a fitness evaluation. During parameterization, its geometry is represented by seven geometric variables. A modified social spider algorithm is used as the optimization algorithm. To evaluate the aerodynamic performance of the grille, a special fitness function is adopted, obtained using an adaptive topological multi-layer feedforward artificial neural network. To verify the feasibility of this method, experiments and numerical calculations are carried out on the original and optimized intake grilles. The results show that the average intake flow rate and average total pressure recovery coefficient of the optimized grille have increased by 17.3% and 4.9%, respectively.
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