Homogenized finite element analysis on effective elastoplastic mechanical behaviors of composite with imperfect interfaces

A three-dimensional (3D) representative volume element (RVE) model was developed for analyzing effective mechanical behavior of fiber-reinforced ceramic matrix composites with imperfect interfaces. In the model, the fiber is assumed to be perfectly elastic until its tensile strength, and the ceramic material is modeled by an elasto-plastic Drucker-Prager constitutive law. The RVE model is then used to study the elastic properties and the tensile strength of composites with imperfect interfaces and validated through experiments. The imperfect interfaces between the fiber and the matrix are taken into account by introducing some cohesive contact surfaces. The influences of the interface on the elastic constants and the tensile strengths are examined through these interface models

Diagnosis and microecological characteristics of aerobic vaginitis in outpatients based on preformed enzymes

AbstractObjectiveAerobic vaginitis (AV) is a recently proposed term for genital tract infection in women. The diagnosis of AV is mainly based on descriptive diagnostic criteria proposed by Donders and co-workers. The objective of this study is to report AV prevalence in southwest China using an objective assay kit based on preformed enzymes and also to determine its characteristics.Materials and methodsA total of 1948 outpatients were enrolled and tested by a commercial diagnostic kit to investigate the AV prevalence and characteristics in southwestern China. The study mainly examined the vaginal ecosystem, age distribution, Lactobacillus amount, and changes in pH. Differences within groups were analyzed by Wilcoxon two-sample test.ResultsThe AV detection rate is 15.40%. The AV patients were usually seen in the sexually active age group of 20–30 years, followed by those in the age group of 30–40 years. The vaginal ecosystems of all the patients studied were absolutely abnormal, and diagnosed to have a combined infection [aerobic vaginitis (AV) + bacterial vaginitis (BV) 61.33%; 184/300]. Aerobic bacteria, especially Staphylococcus aureus and Escherichia coli, were predominantly found in the vaginal samples of these women.ConclusionAV is a common type of genital infection in southwestern China and is characterized by sexually active age and combined infection predominated by the AV and BV type

An improved plating assay for determination of phage titer

Phage is a virus that is parasitic on bacteria. It is very important to determine the titer of test sample in the study of phage. In this study, an improved plating assay was developed for detection of the number of recombinant phage Cap-T7 present in a test solution at a certain dilution point by counting the plaque forming units. The data demonstrated that the improved plating assay is fast, useful, and convenient for the determination of the phage titer in a sample.Keywords: Phage Cap-T7, detection method, plaque forming unit

Allele frequency analysis of Chinese chestnut (Castanea mollissima) populations using fluorescent simple sequence repeats (SSR) analysis

The aim of this study was to establish a method for allele frequency detection in bulk samples. The abundance of polymerase chain reaction (PCR) products in bulk leaf samples was detected using fluorescent labeled Simple sequence repeat (SSR) primers and an Applied biosystems (AB) automatic DNA analyzer. Compared with the conventional SSR technique based on polyacrylamide gel electrophoresis (PAGE) and silver staining, fluorescent SSR was much more sensitive. A total of 78 alleles, an average of 4.6 alleles per locus, were detected among 17 chestnut populations with the primer CmTCR10 (NED) and a total of 41 alleles, an average of 2.4 alleles per locus, were detected with the primer CmTCR24 (6-FAM). Multiplexing the PCR reaction by combining the primer pairs of CmTCR10 and CmTCR24, using different fluorescent dyes for different primers, showed that the alleles could be discriminated and the sizes of the amplified segments were similar. Furthermore, the exact sizes of the amplified fragments and the abundance of the PCR products were determined by fluorescent SSR. After data analysis with GeneScan software and allele calling and output with Genotyper software, allele frequencies were calculated for equal pooled samples in each population using the FREQS-R module in the R statistical computing language. The results indicate that it is feasible to determine allele frequencies in bulked samples based on the detection of SSR-PCR products. The advantages and additional applications of this method are also discussed. The abundance of the PCR products can be used to determine the allele frequencies in bulk samples of chestnut populations.Keywords: Fluorescent simple sequence repeats (SSR), chestnut population, bulk sampling, allele frequencie

The Fumigating Activity of Litsea cubeba oil and Citral on Solenopsis invicta

This paper studied the fumigating activity of Litsea cubeba oil and citral on Solenopsis invicta, identified and analyzed the chemical constituents and volatile components of L. cubeba oil via solid-phase microextraction which were then identified via gas chromatography-mass spectrometry. The results showed that citral and (z)-3,7-dimethylocta-2,6-diena were the main components of L. cubeba oil, as well as its volatile compounds. According to the experimental results, L. cubeba oil and citral had good fumigating activity on workers, and also had significant inhibition on the walking ability and climbing ability of workers. At the same time, the effects of the two agentia on the fumigating activity and behavioral inhibition of microergate were stronger than those of macroergate. After treating with L. cubeba oil and citral for 24 hours, the walking rate and grasping rate of microergate were both 0 %. The results showed that L. cubeba oil and citral had good control effect on S. invicta

Beimingwu: A Learnware Dock System

The learnware paradigm proposed by Zhou [2016] aims to enable users to reuse numerous existing well-trained models instead of building machine learning models from scratch, with the hope of solving new user tasks even beyond models' original purposes. In this paradigm, developers worldwide can submit their high-performing models spontaneously to the learnware dock system (formerly known as learnware market) without revealing their training data. Once the dock system accepts the model, it assigns a specification and accommodates the model. This specification allows the model to be adequately identified and assembled to reuse according to future users' needs, even if they have no prior knowledge of the model. This paradigm greatly differs from the current big model direction and it is expected that a learnware dock system housing millions or more high-performing models could offer excellent capabilities for both planned tasks where big models are applicable; and unplanned, specialized, data-sensitive scenarios where big models are not present or applicable. This paper describes Beimingwu, the first open-source learnware dock system providing foundational support for future research of learnware paradigm.The system significantly streamlines the model development for new user tasks, thanks to its integrated architecture and engine design, extensive engineering implementations and optimizations, and the integration of various algorithms for learnware identification and reuse. Notably, this is possible even for users with limited data and minimal expertise in machine learning, without compromising the raw data's security. Beimingwu supports the entire process of learnware paradigm. The system lays the foundation for future research in learnware-related algorithms and systems, and prepares the ground for hosting a vast array of learnwares and establishing a learnware ecosystem

Radiosensitization and growth inhibition of cancer cells mediated by an scFv antibody gene against DNA-PKcs in vitro and in vivo

<p>Abstract</p> <p>Background</p> <p>Overexpression of DNA-dependent protein kinase catalytic subunit (DNA-PKcs) is commonly occurred in cancers and causes radioresistance and poor prognosis. In present study, the single-chain variable antibody fragments (scFv) targeting DNA-PKcs was developed for the application of radiosensitization in vitro and in vivo. A humanized semisynthetic scFv library and the phage-display antibodies technology were employed to screen DNA-PKcs scFv antibody.</p> <p>Methods</p> <p>DNA-PKcs epitopes were predicted and cloned. A humanized semisynthetic scFv library and the phage-display antibodies technology were employed to screen DNA-PKcs scFv antibody. DNA damage repair was analyzed by comet assay and immunofluorescence detection of γH2AX foci. The radiosensitization in vivo was determined on Balb/c athymic mice transplanted tumours of HeLa cells.</p> <p>Results</p> <p>Four epitopes of DNA-PKcs have been predicted and expressed as the antigens, and a specific human anti-DNA-PKcs scFv antibody gene, anti-DPK3-scFv, was obtained by screening the phage antibody library using the DNA-PKcs peptide DPK3. The specificity of anti-DPK3-scFv was verified, <it>in vitro</it>. Transfection of HeLa cells with the anti-DPK3-scFv gene resulted in an increased sensitivity to IR, decreased repair capability of DNA double-strand breaks (DSB) detected by comet assay and immunofluorescence detection of γH2AX foci. Moreover, the kinase activity of DNA-PKcs was inhibited by anti-DPK3-scFv, which was displayed by the decreased phosphorylation levels of its target Akt/S473 and the autophosphorylation of DNA-PKcs on S2056 induced by radiation. Measurement of the growth and apoptosis rates showed that anti-DPK3-scFv enhanced the sensitivity of tumours transplanted in Balb/c athymic mice to radiation therapy.</p> <p>Conclusion</p> <p>The antiproliferation and radiosensitizing effects of anti-DPK3-scFv via targeting DNA-PKcs make it very appealing for the development as a novel biological radiosensitizer for cancer therapeutic potential.</p

Effects of total flavonoids from Drynariae Rhizoma prevent bone loss in vivo and in vitro

AbstractEstrogen deficiency is one of the major causes of osteoporosis in postmenopausal women. Drynariae Rhizoma is a widely used traditional Chinese medicine for the treatment of bone diseases. In this study, we investigated the therapeutic effects of the total Drynariae Rhizoma flavonoids (DRTF) on estrogen deficiency-induced bone loss using an ovariectomized rat model and osteoblast-like MC3T3-E1 cells. Our results indicated that DRTF produced osteo-protective effects on the ovariectomized rats in terms of bone loss reduction, including decreased levels of bone turnover markers, enhanced biomechanical femur strength and trabecular bone microarchitecture deterioration prevention. In vitro experiments revealed that the actions of DRTF on regulating osteoblastic activities were mediated by the estrogen receptor (ER) dependent pathway. Our data also demonstrated that DRTF inhibited osteoclastogenesis via up-regulating osteoprotegrin (OPG), as well as down-regulating receptor activator of NF–κB ligand (RANKL) expression. In conclusion, this study indicated that DRTF treatment effectively suppressed bone mass loss in an ovariectomized rat model, and in vitro evidence suggested that the effects were exerted through actions on both osteoblasts and osteoclasts