Search

During October-December 2016, the number of norovirus outbreaks in China increased sharply from the same period during the previous 4 years. We identified a recombinant norovirus strain, GII.P16-GII.2, as the cause of 44 (79%) of the 56 outbreaks, signaling that this strain could replace the predominant GII.4 viruses. [ABSTRACT FROM AUTHOR]

This paper focuses on sliding bifurcation of an electromechanical coupling drive system drived by AC synchronous motor containing friction under external excitation along with the changes of external excitation frequency. Considering the mixed friction on load side, the electromagnetic coupling torque provided by motor side and the external disturbance torque on load side, the dynamical equation of an electromechanical coupling drive system containing friction under external excitation can be deduced according to Newton's laws. The stability of periodic solutions in the system is analyzed with Floquet theory. The Filippov convex method is used to extend the system and theoretical conditions of the stick-slip motion are given to numerically predict the sliding bifurcation. The influence of external excitation frequency on the dynamic behavior of drive system is observed and the dynamic behavior of system is verified whether it meets the conditions of sliding bifurcation. Numerical simulations are also given to confirm the results. [ABSTRACT FROM AUTHOR]

"Three new developments" is the guiding ideology of Chinese-style high-quality development in the new era. Jujube (Zizyphus jujube Mill.) is a plant of Zizyphus of Rhamnaceae, which originated in China and has been listed as one of the "five fruits" since ancient times. Xinjiang is the most important jujube producing area in China, and its yield has accounted for 50% of the national jujube yield. In the five prefectures and cities of southern Xinjiang, as well as the regimental farms of southern and eastern Xinjiang of Xinjiang Production and Construction Corps, the jujube industry is an advantageous characteristic industry in agriculture. This paper studied Xinjiang jujube industry and its agricultural intellectual property resources, analyzed six major issues to be further implemented, such as the "three new developments" thinking and the strategy of building an intellectual property power, and puts forward eight strategies such as coordinating the two markets and two resources to accelerate the construction of a new development pattern and dual circulation of jujube. [ABSTRACT FROM AUTHOR]

3-Amino-2-carbamimidoylacrylamides were efficiently prepared via a copper(I)-catalyzed three-component reaction of sulfonylazides, propriolamides, and amidines. The synthesized compounds provided three kinds of crystalline structures based on the position of halogen. Two of them presented channel-type inclusion complexes with ethyl acetate through intermolecular hydrogen bonding, intermolecular C–H...π and π–π interactions, and van der Waals forces. [ABSTRACT FROM AUTHOR]

Leojaponin (2), a labdane diterpene, was isolated from the EtOH extract of the herb of Leonurus japonicus together with a new halimane diterpene named isoleojaponin (1). Isoleojaponin has a new diterpene skeleton with a unique cross-conjugated α,β-unsaturated ketone system, Their structures were elucidated by physical and spectroscopic analysis, and the relative configuration of the chiral C-9 carbon was determined by a computational method, and analysis of its possible biogenesis pathways. [ABSTRACT FROM AUTHOR]

This study was conducted to evaluate the feasibility and accuracy of available arsenic (As) measurement in soils using the diffusive gradients in thin films (DGT) technique and to shed further light on the risk evaluation of As-contaminated soils. A bio-indicator method was used to evaluate the dependence of As concentrations in plant tissues (edible rape) on the As concentrations measured by other methods. DGT, extraction of soil pore water, 0.5 M NaHCO3, 1 M HCl, 1 M NH4Cl, 0.5 M NH4F, 0.1 M NaOH and 0.25 M H2SO4 extraction methods, as well as total As content in the soil were employed in this study. Edible rape was grown in 43 soils containing different concentrations of As. A better correlation was obtained between the As concentrations in plant tissues and the As concentrations measured by DGT than between plant concentrations and those measured by other methods. The coefficients of determination (R²) before and after growth of edible rape were 0.84 and 0.83, respectively. Levels of As in plants and in soil pore water were also closely related: the coefficients of determination (R²) between these variables before and after growth of edible rape were 0.83 and 0.81, respectively. Measurements from the chemical extraction methods were inferior to those from DGT and soil pore water. Levels of As in plants were more scattered and nonlinear with respect to total soil As content (R² = 0.27). The As measured by DGT closely reflected the pool of plant-adsorbed As. From the data obtained in this study, we can conclude that DGT is an effective technique for the prediction and assessment of As bioavailability in soils. [ABSTRACT FROM AUTHOR]

One complete mitochondrial genome (mitogenome) was determined for a deep-sea holothurian species of the genus Synallactes (Synallactida: Synallactidae). The mitochondrial genome size of the sea cucumber was 15,920 bp. The sequence contains 2 ribosomal RNA genes (12S and 16S), 22 transfer RNA genes, and 13 protein-coding genes, as found in most previously determined holothurian mitogenomes. The AþT content of the complete mitochondrial genome sequence was 64.45%. The base composition showed a tendency of AT. The resulted maximum likelihood (ML) tree of Holothuroidea supported that Synallactes sp. is a species of Synallactida. [ABSTRACT FROM AUTHOR]

Background: Associations between transcription factor 7-like 2 (TCF7L2) polymorphisms and type 2 diabetes mellitus (T2DM) have been evaluated extensively in multiple ethnic groups. TCF7L2 has emerged as the strongest T2DM susceptibility gene in Europeans, but the findings have been inconsistent in the Chinese population. The purpose of this meta-analysis was to evaluate the associations between TCF7L2 single nucleotide polymorphisms (SNPs) and T2DM risk in the Chinese population. Methods: We performed searches in the PubMed, EMBASE, Cochrane, and Chinese databases (CNKI, CQVIP and Wanfang databases) for literature published from January 2007 to February 2012. We reviewed all relevant articles on TCF7L2 polymorphisms and susceptibility to T2DM in the Chinese population written in English and Chinese. Two reviewers extracted data independently using a standardized protocol, and any discrepancies were adjudicated by a third reviewer. Fixed-effects and random-effects meta-analyses were performed to pool the odds ratios (ORs). Publication bias and heterogeneity were examined. Results: A total of 21 articles were confirmed to be eligible for and included in this meta-analysis: 7 (with 3942 cases and 3502 controls) concerning rs11196218 (IVS-/+4G>A), 8 (with 3377 cases and 2975 controls) concerning rs290487 (IVS3-/+C>T), and 14 (with 7902 cases and 7436 controls) concerning rs7903146 (IVS3-/+C>T). Overall, the results showed a significant association between rs7903146 and T2DM risk. The pooled ORs were 1.54 for the comparison of T and C alleles (95% CI [confidence interval]: 1.37-1.74, p = 1.47 × 10-12, I2 = 25.20%) and 1.56 for TC heterozygotes and CC homozygotes (95% CI : 1.38-1.76, p = 8.25 × 10-9, I2 = 21.00%). The rs11196218(IVS4G>A) and rs290487 (IVS3C>T) SNPs were not associated with T2DM risk. Conclusions: The rs7903146 SNP of the TCF7L2 gene is associated with increased susceptibility to T2DM in the Chinese population as a whole as well as northern Chinese and southern Chinese as subgroups. [ABSTRACT FROM AUTHOR]

The accuracy of most of the existing semisupervised clustering algorithms based on small size of labeled dataset is low when dealing with multidensity and imbalanced datasets, and labeling data is quite expensive and time consuming in many real-world applications. This paper focuses on active data selection and semisupervised clustering algorithm in multidensity and imbalanced datasets and proposes an active semisupervised clustering algorithm. The proposed algorithm uses an active mechanism for data selection to minimize the amount of labeled data, and it utilizes multithreshold to expand labeled datasets on multidensity and imbalanced datasets. Three standard datasets and one synthetic dataset are used to demonstrate the proposed algorithm, and the experimental results show that the proposed semisupervised clustering algorithm has a higher accuracy and a more stable performance in comparison to other clustering and semisupervised clustering algorithms, especially when the datasets are multidensity and imbalanced. [ABSTRACT FROM AUTHOR]

Megalobrama pellegrini is an endemic fish species found in the upper Yangtze River basin in China. This species has become endangered due to the construction of the Three Gorges Dam and overfishing. However, the available genetic data for this species is limited. Here, we developed 26 polymorphic microsatellite markers from the M. pellegrini genome using next-generation sequencing techniques. A total of 257,497 raw reads were obtained from a quarter-plate run on 454 GS-FLX titanium platforms and 49,811 unique sequences were generated with an average length of 404 bp; 24,522 (49.2%) sequences contained microsatellite repeats. Of the 53 loci screened, 33 were amplified successfully and 26 were polymorphic. The genetic diversity in M. pellegrini was moderate, with an average of 3.08 alleles per locus, and the mean observed and expected heterozygosity were 0.47 and 0.51, respectively. In addition, we tested cross-species amplification for all 33 loci in four additional breams: M. amblycephala, M. skolkovii, M. terminalis, and Sinibrama wui. The cross-species amplification showed a significant high level of transferability (79%-97%), which might be due to their dramatically close genetic relationships. The polymorphic microsatellites developed in the current study will not only contribute to further conservation genetic studies and parentage analyses of this endangered species, but also facilitate future work on the other closely related species. [ABSTRACT FROM AUTHOR]

Examines the detection of negative ions from individual ultrafine particles. Use of aerosol mass spectrometers in classifying airborne particles; Ablation efficiency of negative ions; Creation of electrons in the ablation process.

A disintegrin and metalloproteinase 3 (ADAM3) is a sperm membrane protein critical for sperm migration from the uterus into the oviduct and sperm-egg binding in mice. Disruption of PRSS37 results in male infertility concurrent with the absence of mature ADAM3 from cauda epididymal sperm. However, how PRSS37 modulates ADAM3 maturation remains largely unclear. Here, we determine the PRSS37 interactome by GFP immunoprecipitation coupled with mass spectrometry in PRSS37-EGFP knock-in mice. Three molecular chaperones (CLGN, CALR3 and PDILT) and three ADAM proteins (ADAM2, ADAM6B and ADAM4) were identified to be interacting with PRSS37. Coincidently, five of them (except ADAM4) have been reported to interact with ADAM3 precursor and regulate its maturation. We further demonstrated that PRSS37 also interacts directly with ADAM3 precursor and its deficiency impedes the association between PDILT and ADAM3. This could contribute to improper translocation of ADAM3 to the germ cell surface, leading to ADAM3 loss in PRSS37-null mature sperm. The understanding of the maturation mechanisms of pivotal sperm plasma membrane proteins will pave the way toward novel strategies for contraception and the treatment of unexplained male infertility. [ABSTRACT FROM AUTHOR]

Passive imaging for mid-wave infrared (MWIR) is resistant to atmospheric pollutants, guaranteeing image clarity and accuracy. Arrayed photodetectors can simultaneously perform radiation sensing to improve efficiency. Room temperature van der Waals (vdWs) photodetectors without lattice matching have evolved rapidly with optimized stacking methods, primarily for single-pixel devices. The urgent need to implement arrayed devices aligns with practical demands. Here, we present an 8 by 1 black phosphorus/molybdenum sulfide (BP/MoS2) vdWs photodetector linear array with a fill-factor of ~77%, fabricated using a temperature-assisted sloping transfer method. The flat interface and uniform thickness facilitate carrier transport and minimize pixel nonuniformities, showing an average peak detectivity (D*) of 2.34 × 109 cm·Hz1/2·W-1 in the mid-wave infrared region. Compared to a single pixel, push-broom scanning passive imaging is eight times more efficient and further enhanced through mean filtering and fast Fourier transform filtering for strip noise correction. Our study offers guidance on vdWs arrayed devices for engineering applications. [ABSTRACT FROM AUTHOR]

To propose a sensory evaluation method suitable for Qingzhuan tea, a representative Qingzhuan tea produced in Hubei was soak or spray boiled in order to analyze the effects of different boiling conditions on the sensory quality and the leaching rate of major chemical components of Qingzhuan tea. The sensory quality and chemical components of the tea infusions were compared with those of tea infusion obtained by the brewing method specified in the Chinese national standard. The results showed that the sensory quality of the boiled tea infusion was significantly better than that of the brewed tea infusion; the leaching rates of major quality components such as water extract, tea polyphenols, amino acids, soluble sugars and tea pigments were much higher in the former than in the latter. From the perspectives of sensory quality and the leaching rate of major quality components, tea infusion prepared by boiling for 2 min with a tea/water ratio of 1:80 and then standing for 2–4 min tasted moderate and had good internal quality. Further correlation analysis showed high correlation coefficients between the leaching rates of soluble sugars, theabrownine and water extract and taste quality. The results of this study provide a reference for the objective evaluation of the sensory quality of Qingzhuan tea and other types of compressed tea.

Background The transmission speed and concealment of the Omicron variant of SARS-CoV-2 have been enhanced. The awareness level and skills of correctly donning and doffing personal protective equipment (PPE) in SARS-CoV-2 containment workers from the mobile cabin hospital are associated with their own health status, and the overall quality of COVID-19 pandemic control. Objective To understand the awareness and skills of correctly donning and doffing PPE in SARS-CoV-2 containment workers from a mobile cabin hospital. Methods By use of cluster sampling, 460 SARS-CoV-2 containment workers were selected from the Fourth Branch of Shanghai Mobile Cabin Hospital located in the National Exhibition and Convention Center (Shanghai) , from April 10 to May 10, 2022. Their awareness and skills of correctly donning and doffing PPE were assessed using an online survey with a self-developed questionnaire named Awareness of Correctly Donning and Doffing Personal Protective Equipment, and using an onsite performance assessment with a self-developed questionnaire named Skills of Correctly Donning and Doffing Personal Protective Equipment, respectively. Results The survey obtained a response rate of 83.5% (384/460) . According to the survey, both doctors and nurses had significantly higher average scores with regards to the operations at the first donning area, second donning area, front doffing area and first doffing area, second doffing area, and hand hygiene disinfection than public security officers and fire fighters (P

As the place where students live for the longest time, the levels, sources and health risks of heavy metals in road dust from university campuses have not been widely studied. In the present study, 41 road dust samples were collected and analyzed by ICP-MS for Zn, V, Pb, Cr, Ni and Cu. The isotopic composition of Pb was analyzed by MC-ICP MS. These heavy metals were specifically analyzed using enrichment factor, geoaccumulation index, principal component analysis, iso-sources model and health risk assessment model. Zn and Pb pollution levels were high in road dust, and they were defined as moderate enrichment and contaminated. The sources of Pb in road dust from university campus were traffic exhaust, steel smelting, soil, and fly ash, accounting for 59.4%, 23.2%, 12.2%, and 5.2%, respectively. The non-carcinogenic risk of female and male university students is safe, but the carcinogenic risk of Cr needs to be concerned by the authorities. [ABSTRACT FROM AUTHOR]

Anisomycin (compound 1), a pyrrolidine antibiotic, exhibits diverse biological and pharmacologic activities. The biosynthetic gene cluster of compound 1 has been identified previously, and the multistep assembly of the core benzylpyrrolidine scaffold was characterized. However, enzymatic modifications, such as acylation, involved in compound 1 biosynthesis are unknown. In this study, the genetic manipulation of aniI proved that it encoded an indispensable acetyltransferase for compound 1 biosynthesis. Bioinformatics analysis suggested AniI as a member of maltose (MAT) and galactoside O-acetyltransferases (GAT) with C-terminal left-handed parallel beta-helix (LbH) subdomain, which were referred to as LbH-MAT-GAT sugar O-acetyltransferases. However, the biochemical assay identified that its target site was the hydroxyl group of the pyrrolidine ring. AniI was found to be tolerant of acyl donors with different chain lengths for the biosynthesis of compound 1 and derivatives 12 and 13 with butyryl and isovaleryl groups, respectively. Meanwhile, it showed comparable activity toward biosynthetic intermediates and synthesized analogues, suggesting promiscuity to the pyrrolidine ring structure of compound 1. These data may inspire new viable synthetic routes for the construction of more complex pyrrolidine ring scaffolds in compound 1. Finally, the overexpression of aniI under the control of strong promoters contributed to the higher productivities of compound 1 and its analogues. These findings reported here not only improve the understanding of anisomycin biosynthesis but also expand the substrate scope of Oacetyltransferase working on the pyrrolidine ring and pave the way for future metabolic engineering construction of high-yield strains. [ABSTRACT FROM AUTHOR]