890 research outputs found

    Newly recognized mosquito-associated viruses in mainland China, in the last two decades

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    There are four principal arboviruses in mainland China. Two kinds of them are mosquito-borne viruses, namely Japanese encephalitis virus and dengue virus, which lead to Japanese encephalitis, and dengue fever/dengue hemorrhagic fever respectively; the other two are tick-borne viruses, namely tick-borne encephalitis virus and Crimean-Congo hemorrhagic fever virus (also known as Xinjiang hemorrhagic fever virus), which contribute to tick-borne encephalitis and Xinjiang hemorrhagic fever respectively. With exception of these four main arboviruses, many other mosquito-associated viruses have been isolated and identified in recent years. These newly isolated and identified mosquito-associated viruses are probably responsible for human and animal infections and diseases. The purpose of this review is to describe the newly isolated mosquito-associated viruses in mainland China which belong to five viral families, including their virological properties, phylogenetic relationships, serological evidence, as well as to appeal the public health concentration worldwide

    Supplier Selection Model Based on D Numbers and Transformation Function

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    Selecting reasonable suppliers can effectively improve the efficiency of enterprise supply chain management. Among them, expert evaluation is an important part of supplier selection problem, but the uncertainty, fuzziness and incompleteness of expert opinions make supplier selection problem difficult to solve. In order to systematically and effectively solve the uncertainty, ambiguity and incompleteness in supplier selection problem, this paper presents a new supplier selection method based on D numbers and transformation function. First, fuzzy preference relation is generated based on the decision matrix of pairwise comparisons given by experts. D numbers which can effectively deal with uncertain information extend fuzzy preference relation (D matrix). Second, the D matrix is converted into a crisp matrix form based on the integration representation of D numbers according to different situations whether or not the information in D matrix is complete. Third, the crisp matrix is converted into judgement matrix by using the transformation functions. Finally, analytic hierarchy process (AHP) method is applied based on the judgment matrix to give a priority weights for decision making. Three numerical examples and application of the supplier selection are used to show the feasibility and effectiveness of the proposed method

    CSM-H-R: An Automatic Context Reasoning Framework for Interoperable Intelligent Systems and Privacy Protection

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    Automation of High-Level Context (HLC) reasoning for intelligent systems at scale is imperative due to the unceasing accumulation of contextual data in the IoT era, the trend of the fusion of data from multi-sources, and the intrinsic complexity and dynamism of the context-based decision-making process. To mitigate this issue, we propose an automatic context reasoning framework CSM-H-R, which programmatically combines ontologies and states at runtime and the model-storage phase for attaining the ability to recognize meaningful HLC, and the resulting data representation can be applied to different reasoning techniques. Case studies are developed based on an intelligent elevator system in a smart campus setting. An implementation of the framework - a CSM Engine, and the experiments of translating the HLC reasoning into vector and matrix computing especially take care of the dynamic aspects of context and present the potentiality of using advanced mathematical and probabilistic models to achieve the next level of automation in integrating intelligent systems; meanwhile, privacy protection support is achieved by anonymization through label embedding and reducing information correlation. The code of this study is available at: https://github.com/songhui01/CSM-H-R.Comment: 11 pages, 8 figures, Keywords: Context Reasoning, Automation, Intelligent Systems, Context Modeling, Context Dynamism, Privacy Protection, Context Sharing, Interoperability, System Integratio

    Tricin protects rats from ovariectomized-induced osteoporosis by enhancing Wnt/β-catenin pathway

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    Purpose: To investigate the effects of tricin on ovariectomized-induced osteoporosis, and unravel theunderling mechanism of action.Methods: An osteoporosis rat model was established by conducting ovariectomy (OVX). Changes in the microstructure of the trabecular bone were visualized using Hematoxylin and eosin (H&E) staining, and a three-point bending test was employed to assess the biomechanical stability of the femurs, after the administration of tricin (20 and 40 mg/kg). Subsequently, bone marrow mesenchymal stem cells (BMSCs) were isolated and treated with tricin (7 and 15 μM). Alizarin red staining was performed to assess mineralization, and Runt-related transcription factor 2 (RUNX2); osteocalcin (OCN) and collagen type I alpha 1 (Col1a1) were quantified using western blot analysis. The Wnt/β-catenin pathway related proteins, i.e., Wnt3a, β-catenin, glycogen synthase kinase-3 β (GSK-3 β) were determined.Results: Ovariectomy induced thinner and discontinuous trabecular bone, with increased marrow cavities, while application of tricin significantly improved the density and regularity meshwork, but reduced marrow cavities. Tricin also enhanced biomechanical competence as seen in the upregulated maximum load, stiffness, young modulus and maximum stress compared with OVX group (p < 0.01). Furthermore, tricin increased calcification in BMSCs, and significantly upregulated the expressions of RUNX2, OCN and COL1A1 when compared with OVX group (p < 0.01). It promoted Wnt/β-catenin signaling by enhancing Wnt3a and β-catenin, while inhibiting GSK3β expression, compared with OVX group (p < 0.05 or p < 0.01).Conclusion: Tricin exerts protective effects against OVX-induced osteoporosis by enhancing Wnt/β-catenin pathway. Thus, tricin is a potential therapeutic agent for the management of osteoporosis

    Validity of self-reported weight, height and resultant body mass index in Chinese adolescents and factors associated with errors in self-reports

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    <p>Abstract</p> <p>Background</p> <p>Validity of self-reported height and weight has not been adequately evaluated in diverse adolescent populations. In fact there are no reported validity studies conducted in Asian children and adolescents. This study aims to examine the accuracy of self-reported weight, height, and resultant BMI values in Chinese adolescents, and of the adolescents' subsequent classification into overweight categories.</p> <p>Methods</p> <p>Weight and height were self-reported and measured in 1761 adolescents aged 12-16 years in a cross-sectional survey in Xi'an city, China. BMI was calculated from both reported values and measured values. Bland-Altman plots with 95% limits of agreement, Pearson's correlation and Kappa statistics were calculated to assess the agreement.</p> <p>Results</p> <p>The 95% limits of agreement were -11.16 and 6.46 kg for weight, -4.73 and 7.45 cm for height, and -4.93 and 2.47 kg/m<sup>2 </sup>for BMI. Pearson correlation between measured and self-reported values was 0.912 for weight, 0.935 for height and 0.809 for BMI. Weighted Kappa was 0.859 for weight, 0.906 for height and 0.754 for BMI. Sensitivity for detecting overweight (includes obese) in adolescents was 56.1%, and specificity was 98.6%. Subjects' area of residence, age and BMI were significant factors associated with the errors in self-reporting weight, height and relative BMI.</p> <p>Conclusions</p> <p>Reported weight and height does not have an acceptable agreement with measured data. Therefore, we do not recommend the application of self-reported weight and height to screen for overweight adolescents in China. Alternatively, self-reported data could be considered for use, with caution, in surveillance systems and epidemiology studies.</p

    Hemoglobin levels and anemia evaluation during pregnancy in the highlands of Tibet: a hospital-based study.

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    BACKGROUND: Anemia is regarded as a major risk factor for unfavorable pregnancy outcomes, but there have been no previous studies describing the pattern of hemoglobin concentration during pregnancy in Tibet and the relationship between altitude and Hb concentration in the pregnant women living in Tibet still has not been clearly established. The main objectives of this study were to study the hemoglobin levels and prevalence of anemia among pregnant women living in the highlands of Tibet and to evaluate potential associations of hemoglobin and anemia with women's characteristics. METHODS: The hospital-based study was conducted in 380 pregnant women. Their blood samples were tested and related sociodemographic information was collected. Multiple linear regression model and multiple logistic regression model were used to assess the association of pregnant women's characteristics with hemoglobin level and the occurrence of anemia. Centers for Disease Control (CDC), Dirren et al. and Dallman et al. methods were used to adjust the hemoglobin measurements based on altitude for estimating the prevalence of anemia. RESULTS: The mean hemoglobin concentration was 127.6 g/L (range: 55.0-190.0 g/L). Prevalence rate of anemia in this study was 70.0%, 77.9% and 41.3%, respectively for three altitude-correction methods for hemoglobin (CDC method, Dirren et al. method, and Dallman et al. method). Gestational age, ethnicity, residence and income were significantly associated with the hemoglobin concentration and prevalence of anemia in the study population. Specially, the hemoglobin concentration of pregnant women decreased with increase in gestational age. CONCLUSION: The hemoglobin level was low and prevalence rate of anemia was high among pregnant women in Lhasa, Tibet. Gestational age, ethnicity, residence and income were found to be significantly associated with the hemoglobin level and the occurrence of anemia in the study population

    Adhesion of bio-functionalized ultrasound microbubbles to endothelial cells by targeting to vascular cell adhesion molecule-1 under shear flow

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    The expression of certain endothelial cell adhesion molecules is increased during endothelial dysfunction or inflammatory activation. This has led to the concept of using microbubbles for targeted molecular imaging or drug delivery. In this approach, microbubbles with a specific ligand to receptors expressed at the site of specific diseases are constructed. The present study aimed to engineer a novel type of bio-functionalized microbubbles (vascular cell adhesion molecule 1 [VCAM-1]-targeted microbubbles), and determine whether VCAM-1-targeted microbubbles exhibit specific adhesion to lipopolysaccharide (LPS)-activated endothelial cells. Our data showed that VCAM-1 expression was significantly upregulated in both LPS-activated endothelial cells in vitro and endothelium in a rat atherosclerosis model in vivo. Targeted microbubbles were designed by conjugating anti-VCAM-1 monoclonal antibodies to the shell of microbubbles using biotin–avidin bridging chemistry methods. Microbubble adhesion to endothelial cells was assessed in a flow chamber at two shear stress conditions ( 6.3 and 10.4 dynes/cm2). Our data showed that microbubble adhesion depends on both the surface anti-VCAM-1 antibody densities and the exposed shear stresses. Adhesion of VCAM-1-targeted microbubbles onto LPS-activated endothelial cells increased with the surface antibody densities, and decreased with the exposed shear stresses. These findings showed that the specific ligand-carrying microbubbles have considerable potential in targeted ultrasound molecular imaging or ultrasound-assisted drug/gene delivery applications

    Substrate specificity provides insights into the sugar donor recognition mechanism of O-GlcNAc transferase (OGT).

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    O-Linked β-N-acetylglucosaminyl transferase (OGT) plays an important role in the glycosylation of proteins, which is involved in various cellular events. In human, three isoforms of OGT (short OGT [sOGT]; mitochondrial OGT [mOGT]; and nucleocytoplasmic OGT [ncOGT]) share the same catalytic domain, implying that they might adopt a similar catalytic mechanism, including sugar donor recognition. In this work, the sugar-nucleotide tolerance of sOGT was investigated. Among a series of uridine 5'-diphosphate-N-acetylglucosamine (UDP-GlcNAc) analogs tested using the casein kinase II (CKII) peptide as the sugar acceptor, four compounds could be used by sOGT, including UDP-6-deoxy-GlcNAc, UDP-GlcNPr, UDP-6-deoxy-GalNAc and UDP-4-deoxy-GlcNAc. Determined values of Km showed that the substitution of the N-acyl group, deoxy modification of C6/C4-OH or epimerization of C4-OH of the GlcNAc in UDP-GlcNAc decreased its affinity to sOGT. A molecular docking study combined with site-directed mutagenesis indicated that the backbone carbonyl oxygen of Leu653 and the hydroxyl group of Thr560 in sOGT contributed to the recognition of the sugar moiety via hydrogen bonds. The close vicinity between Met501 and the N-acyl group of GlcNPr, as well as the hydrophobic environment near Met501, were responsible for the selective binding of UDP-GlcNPr. These findings illustrate the interaction of OGT and sugar nucleotide donor, providing insights into the OGT catalytic mechanism

    Persistence, extinction and practical exponential stability of impulsive stochastic competition models with varying delays

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    This paper studies the persistence, extinction and practical exponential stability of impulsive stochastic competition models with time-varying delays. The existence of the global positive solutions is investigated by the relationship between the solutions of the original system and the equivalent system, and the sufficient conditions of system persistence and extinction are given. Moreover, our study shows the following facts: (1) The impulsive perturbation does not affect the practical exponential stability under the condition of bounded pulse intensity. (2) In solving the stability of non-Markovian processes, it can be transformed into solving the stability of Markovian processes by applying Razumikhin inequality. (3) In some cases, a non-Markovian process can produce Markovian effects. Finally, numerical simulations obtained the importance and validity of the theoretical results for the existence of practical exponential stability through the relationship between parameters, pulse intensity and noise intensity
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