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ObjectiveAn analytical method was developed for the qualitative screening of 52 illegally adulterated weight-losing compounds in foods by ultra high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry.MethodsThe samples were extracted by methanol. Waters CORTECS T3 column （100 mm×2.1 mm， 2.7 μm） was used with acetonitrile -0.1% formic acid aqueous solution as mobile phases by gradient elution. The compounds were detected by electrospray ionization mass spectrometry and Q-TOF-MS detector in positive and negative ion mode. A standard spectrum library was established by reference standards， and the qualitative analysis was finished by the comparison of the retention time， parent ion and fragment ion accurate molecular mass of each compound in the sample and the library.ResultsThe method was specific without interference of blank matrix， and repeatable in sextuplicate. The detection limits of 52 compounds in 5 matrix were 1‒100 mg‧kg-1. The method was successfully applied to the analysis of actual samples，and 16 compounds were checked out in 246 samples.ConclusionThe method is accurate， specific and sensitive， which can be used to combat the illegal adulteration behavior effectively.

Objective: Intrahepatic cholestasis of pregnancy (ICP) can cause adverse perinatal outcomes. Previous studies have demonstrated that the placenta of an ICP pregnancy differs in morphology and gene expression from the placenta of a normal pregnancy. To date, however, the genetic mechanism by which ICP affects the placenta is poorly understood. Therefore, the aim of this study was to investigate the differences in main cell types, gene signatures, cell ratio, and functional changes in the placenta between ICP and normal pregnancy. Methods: Single-cell RNA sequencing (scRNA-seq) technology was used to detect the gene expression of all cells at the placental maternal–fetal interface. Two individuals were analyzed – one with ICP and one without ICP. The classification of cell types was determined by a graph-based clustering algorithm. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed using the R software phyper () function and DAVID website. The differentially expressed genes (DEGs) encoding transcription factors (TFs) were identified using getorf and DIAMOND software. Results: We identified 14 cell types and 22 distinct cell subtypes that showed unique functional properties. Additionally, we found differences in the proportions of fibroblasts 1, helper T (Th) cells, extravillous trophoblasts, and villous cytotrophoblasts, and we observed heterogeneity of gene expression between ICP and control placentas. Furthermore, we identified 263 DEGs that belonged to TF families, including zf-C2H2, HMGI/HMGY, and Homeobox. In addition, 28 imprinted genes were preferentially expressed in specific cell types, such as PEG3 and PEG10 in trophoblasts as well as DLK1 and DIO3 in fibroblasts. Conclusions: Our results revealed the differences in cell-type ratios, gene expression, and functional changes between ICP and normal placentas, and heterogeneity was found among cell subgroups. Hence, the imbalance of various cell types affects placental activity to varying degrees, indicating the complexity of the cell networks that form the placental tissue system, and this alteration of placental function is associated with adverse events in the perinatal period. [ABSTRACT FROM AUTHOR]

Layered rocks are widely distributed in mining and underground engineering. The evolution processes, such as crack initiation, development and penetration, inevitably occur due to stress changes. This study carried out an experiment and numerical simulation to explore the correspondence between crack distribution and bedding dip, and to reveal the mechanical mechanism of layered rock fracturing. The results show that the layered rock specimens with different bedding dips obtained different stress combinations under the same uniaxial compression conditions. There are a total of five types of stress combinations, including pure compression type, compression shear type, pure shear type, tension shear type, and pure tension type. The Mohr circle is effective in characterizing the relationship between the stress combinations and failure modes. The failure mode of layered rocks in the range of 0° to 150° is presented the variation features of "tensile failure → compression-shear failure → shear failure → tensile shear failure → tensile failure". Furthermore, the combined distributions of dominant and secondary cracks are summarized into the penetrating mode, the exfoliation mode, the feather crack mode, and the associated mode in high-dip of layered marbles. This paper provides research ideas for stability monitoring and crack tracking of layered rock mass engineering. [ABSTRACT FROM AUTHOR]

It has become clear in current scientific pedagogy that the emersion of students in the scientific process in terms of designing, implementing, and analyzing experiments is imperative for their education; as such, it has been our goal to model this active learning process in the classroom and laboratory in the context of a genuine scientific question. Toward this objective, the National Science Foundation funded a collaborative research grant between a primarily undergraduate institution and a research-intensive institution to study the chemotactic responses of the bacterium "Pseudomonas putida" F1. As part of the project, a new Bioinformatics course was developed in which undergraduates annotate relevant regions of the "P. putida" F1 genome using Integrated Microbial Genomes Annotation Collaboration Toolkit, a bioinformatics interface specifically developed for undergraduate programs by the Department of Energy Joint Genome Institute. Based on annotations of putative chemotaxis genes in "P. putida" F1 and comparative genomics studies, undergraduate students from both institutions developed functional genomics research projects that evolved from the annotations. The purpose of this study is to describe the nature of the NSF grant, the development of the Bioinformatics lecture and wet laboratory course, and how undergraduate student involvement in the project that was initiated in the classroom has served as a springboard for independent undergraduate research projects. (Contains 3 figures, 1 table, and 1 footnote.)

Mobile social networks (MSNs) exploit human mobility and consequent device-to-device contact to opportunistically realize data communication. Thus links in MSNs is dynamic changing over time and strongly influenced by people activities, mining influential nodes is one of the important questions for effective information transmission in MSNs. While traditional centrality definitions are based on the static binary network model and not suitable for time-varying topology structure in mobile social network. Furthermore previous centrality metrics often referred to social attributes about neighbor nodes and contact times, and did not take the contact duration time into consideration. Therefore, this paper proposes a centrality measurement method based on multi-social attributes weighted. We first use the temporal evolution graph model which more accurately depicts the dynamic nature of topology in MSNs. Quantifying human social relations and mobility model as weights for the links, and then we redefine degree of centrality and the measurement of shortest path. Finally, the superiority of the concepts we posed are evaluated in the real data set.

Objective: To explore the cytochrome P450 family 27 subfamily A member 1 (CYP27A1) gene mutations in Chinese women with intrahepatic cholestasis of pregnancy (ICP) and the correlation between CYP27A gene mutations and BA (bile acid) level changes.Methods: In this study, the entire coding region of the CYP27A1 gene was sequenced in 151 Han Chinese women with ICP and 1029 matched samples, and the pathogenicity of identified CYP27A1 gene mutations was judged through evolutionary conservation analysis, computational analysis and protein structure modeling. Finally, we verified the relationship between gene mutations and total serum bile acid (TBA) and cholesterol (CHOL) levels through experiments in cell culture.Results: We identified five heterozygous CYP27A1 missense mutations in five ICP samples. Three online tools, Polyphen-2, MutationTaster and SIFT, predicted that the five CYP27A1 mutations were pathogenic. Furthermore, all five mutations caused marked protein structural changes. Experiments in cells showed that the intracellular and medium levels of TBA in the mutant groups were lower than those in the wild-type group, while the CHOL levels were higher in all mutants except for the R158H mutant.Conclusions: CYP27A1 mutations are associated with the levels of TBA and CHOL, suggesting that CYP27A1 mutations contribute to abnormal total cholesterol and BA levels, which leads to ICP. [ABSTRACT FROM AUTHOR]