The nuclear ribosomal DNA internal transcribed spacer (ITS) has been widely used to assess the fungal composition in different environments by deep sequencing. To evaluate the ITS in the analysis of ...fungal diversity, comparisons of the clustering and taxonomy generated by sequencing with different portions of the whole fragment were conducted in this study. For a total of 83,120 full-length ITS sequences obtained from the UNITE database, it was found that, on average, ITS1 varied more than ITS2 within the kingdom Fungi; this variation included length and GC content variations and polymorphisms, with some polymorphisms specific to particular fungal groups. The taxonomic accuracy for ITS was higher than that for ITS1 or ITS2. The commonly used operational taxonomic unit (OTU) for evaluating fungal diversity and richness assigned several species to a single OTU even with clustering at 99.00% sequence similarity. The clustering and taxonomic capacities did not differ between ITS1 and ITS2. However, the OTU commonality between ITS1 and ITS2 was very low. To test this observation further, 219,741 pyrosequencing reads, including 39,840 full-length ITS sequences, were obtained from 10 soil samples and were clustered into OTUs. The pyrosequencing results agreed with the results of the in silico analysis. ITS1 might overestimate the fungal diversity and richness. Analyses using ITS, ITS1 and ITS2 yielded several different taxa, and the taxonomic preferences for ITS and ITS2 were similar. The results demonstrated that ITS2 alone might be a more suitable marker for revealing the operational taxonomic richness and taxonomy specifics of fungal communities when the full-length ITS is not available.
Abstract
The permeation of marine water can lead to severe degradation of the protective properties of polymer composite coatings. At present, experimental studies on the anticorrosive and mechanical ...properties of polymer composite coatings are relatively mature, but the impermeability and mechanical property changes of the coating during the permeation process are challenging tasks to be studied only by experiments. In this paper, molecular dynamics (MD) models of composite coatings consisting of pure epoxy resin (EP), graphene/epoxy resin (Gr/EP), and graphene oxide/epoxy resin (GO/EP) were constructed respectively. MD simulations were performed to reveal the impermeability and mechanical property changes of composite coatings from an atomic perspective. The results show that GO has strong interfacial interaction with EP and the best effect to enhance the impermeability and mechanical properties of epoxy coatings. NaCl solutions can damage the coating microstructure and occupy the Gr and GO surfaces, causing them to no longer have an enhancing effect. The study of GO/EP coatings with different permeation degrees shows that the mechanical properties of the coating decrease as the penetration degree increases.
Oral cancer (OC) is a common tumour that poses a threat to human health and imposes a heavy burden on countries. This study assessed the burden imposed by OC on the 10 most populous countries from ...1990 to 2019 on the basis of gender, age and socio-demographic index.
Data on incidence, mortality, disability-adjusted life years (DALY) and corresponding age-standardised rates (ASR) for OC in the 10 most populous countries from 1990 to 2019 were derived from the Global Burden of Disease Study 2019. Estimated annual percentage changes were calculated to assess the trends of morbidity, mortality and DALY. The indicator that served as a proxy for survival rate was the supplement of mortality-to-incidence ratio (SMIR) (1 - (M/I)).
The number of new cases, deaths and DALY have increased in all 10 countries in the past 30 years. Trends in age-standardised incidence rates (ASIR), age-standardised mortality rate (ASMR) and age-standardised DALY for OC in the 10 most populous countries varied. The SMIR increased in all countries, with most countries having an SMIR between 30% and 50%. In 2019, the United States had the highest SMIR at 76%, whereas Russia had the lowest at 21.7%. Incidence and mortality were close between male and female subjects in Japan, Indonesia, Mexico, India, Bangladesh and Pakistan. The incidence and mortality in male subjects in the United States, Russia, China and Brazil were two or more times those of female subjects. Gender difference was highest among patients aged 40-69 years.
Trends and gender differences in ASIR, ASMR and age-standardised DALY for OC vary in the 10 most populous countries. Government cancer programs are often expensive to run, especially in countries with large populations. Policy makers need to take these differences into account when formulating policies.
This paper considers the problem of dynamic process monitoring. Based on the recently proposed recursive transformed component statistical analysis (RTCSA), its dynamic counterpart recursive dynamic ...transformed component statistical analysis (RDTCSA) is proposed. With time lag shift technique, the augmented sample covariance matrices are used for eigendecomposition and further data transformation. The obtained dynamic transformed components include dynamic information of measurements, whose statistics are used for process monitoring. The difference between RTCSA and RDTCSA for monitoring time-correlated process data is analyzed, which implies that RDTCSA is more sensitive to dynamic changes. In addition, the detectability of RDTCSA for monitoring time-correlated process data is analyzed in a statistical sense. A numerical simulation and the benchmark Tennessee Eastman process (TEP) both indicate the superior fault detectability of RDTCSA compared with the existing methods. Specifically, RDTCSA can effectively detect fault 15 in TEP with detection rate over 95%.
Graphene aerogels (GAs) are a kind of advanced graphene assemblies, which are quite elastic and can easily restore their original form after compression. The macroscale compression behavior of the ...GAs is the result of microstructural evolution of the graphene sheets. In this paper, the microstructural compression response of honeycomb-like GAs is investigated via coarse-grained molecular dynamics (CGMD) method. Based on the coarse-grained (CG) model of a single-layer graphene, honeycomb-like structures can be built and arranged layer-by-layer to form the complete GA model. CGMD simulations presented in this work are carried out with a TersoffCG potential, which was developed specifically for single-layer graphene. The effects of layer number, size of the graphene sheets and the interlaminar overlap pattern on the compressive behavior of the GAs are studied. Moreover, the stress distribution in graphene networks of the GAs during the compression process is analyzed. Different microscale strain concentrations and stress localizations are discovered in the GAs with different network patterns. Furthermore, a negative Poisson's ratio of the models within a certain range of compressive strain is found, which is related to both the microstructural arrangement and the deformation of graphene sheet.
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In this paper, we developed a new design and preparation method of 2D and 3D composite metamaterial with adjustable isotropic negative hydration expansion (NHE) function based on re-entrant auxetic ...honeycomb. The metamaterial is composed of composite lattice microstructure with hydrogel driving layer and re-entrant framework and prepared by multi-material 3D printer. Experimental, simulation and theoretical investigation were carried out to demonstrate the design method and NHE deformation effects of the metamaterial. It was shown that the effective NHE coefficient depends on the length of the driving layer and the straight bar connecting the lattice microstructures. In addition, a non-monotonic relationship was found between the bandings angle θ2 and the length ratio (s/a) due to the constraint effect on both ends of the composite beam. Through the parameter design of the lattice microstructure, the NHE coefficient of can be adjusted within the range of 0–22.4%. For the 3D sample, the value of the NHE coefficient is among the largest achieved in experiments to date. This work provides a practical method for obtaining 2D and 3D metamaterial with adjustable NHE and can be applied to the design of macro-, micro- and nano-metamaterial.
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•A new design method of 2D/3D composite metamaterial with adjustable negative hydration expansion (NHE) function was developed.•The theory, experimental, and finite element methods were used to demonstrate the NHE deformation effect of the metamaterial.•The NHE coefficient of the metamaterial can be tailored within the range of 0-22.4% by adjusting parameters of the lattice microstructure.
Air brake systems are crucial systems for safe and stable operation of electric multiple units (EMUs). The brake cylinder system, which includes brake cylinders, corresponding pressure sensors, and ...connection pipes, plays a vital role in the EMU air brake system. This is because brake cylinder pressures directly affect the brake operation. Currently, brake cylinder pressures are monitored by univariate control charts, i.e., the brake cylinder system will be considered as faulty if a certain pressure goes beyond its allowed range. Besides, serious sensor hardware faults such as open circuit or short circuit can also be detected by system self-inspection circuits. However, three kinds of faults, including brake cylinder component fault, soft sensor fault, as well as gas leakage fault, cannot be well handled by current monitoring methods if these faults are not very serious. In this paper, a fault detection index called intervariable variance (IVV) is first presented to perform fault detection for these faults. Fault detectability analysis is provided, and the IVV statistic is also compared with the univariate control chart approach. Then, a fault isolation strategy is proposed to distinguish different kinds of faults and determine the location of the occurred fault. Finally, the effectiveness of the proposed fault detection and isolation method is demonstrated via extensive experimental studies that are carried out on the EMU brake test bench of Qingdao Sifang Rolling Stock Research Institute Co., Ltd., China.
The use of local aluminosilicates to serve the local engineering applications could resolve the issue of unpredicted properties of the geopolymer caused by the wide variance in aluminosilicates ...reactivity. The locally available aluminosilicate byproducts (e.g., fly ash FA and granulated ground blast-furnace slag GGBS) in Qingdao were used to synthesize geopolymer cement in this study. Six geopolymer cement mortars with different FA/GGBS ratios were compared with ordinary Portland cement (OPC) and magnesium potassium phosphate cement (MKPC) mortars in terms of workability, setting time, strength development, volume stability and chloride permeability. The use of high volume of GGBS equips the geopolymer mortars with fast setting and high early strength despite poor volume stability. Thus, GGBS geopolymer mortars could potentially replace the high-cost MKPC mortar for rapid rehabilitation in construction. The geopolymer cement mortar with a FA/GGBS ratio of 4 behaves similar to OPC mortars in terms of fluidity, setting time, strength development, volume stability and chloride permeability. Therefore, FA-based geopolymer mortar blended with 20% GGBS could be considered as a high-efficiency, low-cost, eco-friendly and sustainable replacement of OPC mortar. Overall, the geopolymer cement properties could be engineered based on the FA/GGBS ratio in order to serve local engineering applications for the maximum utilization in different scenarios.
•Engineering-oriented properties of geopolymer mortars were characterized.•FA/GGBS ratio dependent geopolymer cement was compared with OPC and MKPC.•Application cost and prospect of geopolymer cement were analyzed.
Lung cancer has become the most common cancer type and caused the most cancer deaths. Lung adenocarcinoma (LUAD) is one of the major type of lung cancer. This study aimed to establish a signature ...based on immune related genes that can predict patients' OS for LUAD.
The expression data of 976 LUAD patients from The Cancer Genome Atlas database (training set) and the Gene Expression Omnibus database (four testing sets) and 1534 immune related genes from the ImmPort database were used for generation and validation of the signature. The glmnet Cox proportional hazards model was used to find the best gene model and construct the signature. To assess the independently prognostic ability of the signature, the Kaplan-Meier survival analysis and Cox's proportional hazards model were performed.
A gene model consisting of 30 immune related genes with the highest frequency after 1000 iterations was used as our signature. The signature demonstrated robust prognostic ability in both training set and testing set and could serve as an independent predictor for LUAD patients in all datasets except GSE31210. Besides, the signature could predict the overall survival (OS) of LUAD patients in different subgroups. And this signature was strongly associated with important clinicopathological factors like recurrence and TNM stage. More importantly, patients with high risk score presented high tumor mutation burden.
This signature could predict prognosis and reflect the tumor immune microenvironment of LUAD patients, which can promote individualized treatment and provide potential novel targets for immunotherapy.
Cadmium is one of the environmental and occupational pollutants and its potential adverse effects on human health have given rise to substantial concern. Cadmium causes damage to the male ...reproductive system via induction of germ-cell apoptosis; however, the underlying mechanism of cadmium-induced reproductive toxicity in Leydig cells remains unclear. In this study, twenty mice were divided randomly into four groups and exposed to CdCl
at concentrations of 0, 0.5, 1.0 and 2.0 mg/kg/day for four consecutive weeks. Testicular injury, abnormal spermatogenesis and apoptosis of Leydig cells were observed in mice. In order to investigate the mechanism of cadmium-induced apoptosis of Leydig cells, a model of mouse Leydig cell line (i.e. TM3 cells) was subjected to treatment with various concentrations of CdCl
. It was found that mitochondrial function was disrupted by cadmium, which also caused a significant elevation in levels of mitochondrial superoxide and cellular ROS. Furthermore, while cadmium increased the expression of mitochondrial fission proteins (DRP1 and FIS1), it reduced the expression of mitochondrial fusion proteins (OPA1 and MFN1). This led to excessive mitochondrial fission, the release of cytochrome c and apoptosis. Conversely, cadmium-induced accumulation of mitochondrial superoxide was decreased by the inhibition of mitochondrial fission through the use of Mdivi-1 (an inhibitor of DRP1). Mdivi-1 also partially prevented the release of cytochrome c from mitochondria to cytosol and attenuated cell apoptosis. Finally, given the accumulation of LC3II and SQSTM1/p62 and the obstruction of Parkin recruitment into damaged mitochondria in TM3 cells, the autophagosome-lysosome fusion was probably inhibited by cadmium. Overall, these findings suggest that cadmium induces apoptosis of mouse Leydig cells via the induction of excessive mitochondrial fission and inhibition of mitophagy.
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