474 research outputs found

    Passenger route choice model and algorithm in the urban rail transit network

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    Purpose: There are several routes between some OD pairs in the urban rail transit network. In order to carry out the fare allocating, operators use some models to estimate which route the passengers choose, but there are some errors between estimation results and actual choices results. The aim of this study is analyzing the passenger route choice behavior in detail based on passenger classification and improving the models to make the results more in line with the actual situations. Design/methodology/approach: In this paper, the passengers were divided into familiar type and strange type. Firstly passenger integrated travel impedance functions of two types were established respectively, after that a multi-route distribution model was used to get the initial route assignment results, then a ratio correction method was used to correct the results taking into account the transfer times, crowd and demand for seats. Finally, a case study for the Beijing local rail transit network is shown. Findings: The numerical example showed that it is logical to take passenger classification and the model and algorithm is effective, the final route choice results are more comprehensive and realistic. Originality/value: The paper offers an improved model and algorithm based on passenger classification for passenger route choice in the urban rail transit network.Peer Reviewe

    Construction by artificial intelligence and immunovalidation of hypoallergenic mite allergen Der f 36 vaccine

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    BackgroundThe house dust mite (HDM) is widely recognized as the most prevalent allergen in allergic diseases. Allergen-specific immunotherapy (AIT) has been successfully implemented in clinical treatment for HDM. Hypoallergenic B-cell epitope-based vaccine designed by artificial intelligence (AI) represents a significant progression of recombinant hypoallergenic allergen derivatives.MethodThe three-dimensional protein structure of Der f 36 was constructed using Alphafold2. AI-based tools were employed to predict B-cell epitopes, which were subsequently verified through IgE-reaction testing. Hypoallergenic Der f 36 was then synthesized, expressed, and purified. The reduced allergenicity was assessed by enzyme-linked immunosorbent assay (ELISA), immunoblotting, and basophil activation test. T-cell response to hypoallergenic Der f 36 and Der f 36 was evaluated based on cytokine expression in the peripheral blood mononuclear cells (PBMCs) of patients. The immunogenicity was evaluated and compared through rabbit immunization with hypoallergenic Der f 36 and Der f 36, respectively. The inhibitory effect of the blocking IgG antibody on the specific IgE-binding activity and basophil activation of Der f 36 allergen was also examined.ResultsThe final selected non-allergic B-cell epitopes were 25–48, 57–67, 107–112, 142–151, and 176–184. Hypoallergenic Der f 36 showed significant reduction in IgE-binding activity. The competitive inhibition of IgE-binding to Der f 36 was investigated using the hypoallergenic Der f 36, and only 20% inhibition could be achieved, which is greatly reduced when compared with inhibition by Der f 36 (98%). The hypoallergenic Der f 36 exhibited a low basophil-stimulating ratio similar to that of the negative control, and it could induce an increasing level of IFN‐γ but not Th2 cytokines IL-5 and IL-13 in PBMCs. The vaccine-specific rabbit blocking IgG antibodies could inhibit the patients’ IgE binding and basophil stimulation activity of Derf 36.ConclusionThis study represents the first application of an AI strategy to facilitate the development of a B-cell epitope-based hypoallergenic Der f 36 vaccine, which may become a promising immunotherapy for HDM-allergic patients due to its reduced allergenicity and its high immunogenicity in inducing blocking of IgG

    High prevalence of plasmid-mediated 16S rRNA methylase gene rmtB among Escherichia coli clinical isolates from a Chinese teaching hospital

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    <p>Abstract</p> <p>Background</p> <p>Recently, production of 16S rRNA methylases by Gram-negative bacilli has emerged as a novel mechanism for high-level resistance to aminoglycosides by these organisms in a variety of geographic locations. Therefore, the spread of high-level aminoglycoside resistance determinants has become a great concern.</p> <p>Methods</p> <p>Between January 2006 and July 2008, 680 distinct <it>Escherichia coli </it>clinical isolates were collected from a teaching hospital in Wenzhou, China. PCR and DNA sequencing were used to identify 16S rRNA methylase and extended-spectrum β-lactamase (ESBL) genes, including <it>armA </it>and <it>rmtB</it>, and in situ hybridization was performed to determine the location of 16S rRNA methylase genes. Conjugation experiments were subsequently performed to determine whether aminoglycoside resistance was transferable from the <it>E. coli </it>isolates via 16S rRNA methylase-bearing plasmids. Homology of the isolates harboring 16S rRNA methylase genes was determined using pulse-field gel electrophoresis (PFGE).</p> <p>Results</p> <p>Among the 680 <it>E. coli </it>isolates, 357 (52.5%), 346 (50.9%) and 44 (6.5%) isolates were resistant to gentamicin, tobramycin and amikacin, respectively. Thirty-seven of 44 amikacin-resistant isolates harbored 16S rRNA methylase genes, with 36 of 37 harboring the <it>rmtB </it>gene and only one harboring <it>armA</it>. The positive rates of 16S rRNA methylase genes among all isolates and amikacin-resistant isolates were 5.4% (37/680) and 84.1% (37/44), respectively. Thirty-one isolates harboring 16S rRNA methylase genes also produced ESBLs. In addition, high-level aminoglycoside resistance could be transferred by conjugation from four <it>rmtB</it>-positive donors. The plasmids of incompatibility groups IncF, IncK and IncN were detected in 34, 3 and 3 isolates, respectively. Upstream regions of the <it>armA </it>gene contained <it>IS</it>CR1 and <it>tnpU</it>, the latter a putative transposase gene,. Another putative transposase gene, <it>tnpD</it>, was located within a region downstream of <it>armA</it>. Moreover, a transposon, Tn<it>3</it>, was located upstream of the <it>rmtB</it>. Nineteen clonal patterns were obtained by PFGE, with type H representing the prevailing pattern.</p> <p>Conclusion</p> <p>A high prevalence of plasmid-mediated <it>rmtB </it>gene was found among clinical <it>E. coli </it>isolates from a Chinese teaching hospital. Both horizontal gene transfer and clonal spread were responsible for the dissemination of the <it>rmtB </it>gene.</p

    Efficacy, Safety, and Immunogenicity of an Escherichia coliProduced Bivalent Human Papillomavirus Vaccine: An Interim Analysis of a Randomized Clinical Trial

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    HPV是一种常见的生殖道感染病毒,高危型HPV持续性感染能够导致几乎所有的宫颈癌,其中HPV 16型和18型危害最大,可导致约70%的宫颈癌。预防性HPV疫苗有望减少甚至最终消灭由疫苗型别导致的宫颈癌,降低HPV相关的疾病负担。该研究是在全国4个中心5个现场的18-45岁健康女性中进行的多中心、随机、双盲、对照(戊肝疫苗)的三期临床试验,该研究结果证实我校自主研发的双价人乳头瘤病毒疫苗(大肠杆菌)具有良好的安全性、免疫原性和免疫持久性,可有效地预防HPV 16型和/或18型相关的宫颈高度癌前病变及持续性感染。 该论文报告了我校和厦门万泰沧海生物技术有限公司自主研发的双价人乳头瘤病毒疫苗(大肠杆菌)三期临床试验的期中分析结果。这是第一个进入临床试验并提交药品注册申请的国产人乳头瘤病毒疫苗(HPV疫苗),有望成为世界上第四个上市的HPV疫苗,受到世界卫生组织和盖茨基金会等国际组织的高度关注。 中国医学科学院肿瘤医院乔友林教授、我校吴婷教授、广西壮族自治区疾病预防控制中心李荣成主任医师、江苏省疾病预防控制中心胡月梅主任医师、北京大学人民医院魏丽惠教授、中国食品药品检定研究院李长贵研究员、中国医学科学院肿瘤医院陈汶教授为该论文的共同第一作者,我校张军教授、夏宁邵教授和中国医学科学院肿瘤医院乔友林教授为该论文的共同通讯作者。【Abstract】Background The high cost and insufficient supply of human papillomavirus (HPV) vaccines have slowed the pace of controlling cervical cancer. A phase 3 clinical trial was conducted to evaluate the efficacy, safety and immunogenicity of a novel Escherichia coli-produced bivalent HPV-16/18 vaccine. Methods A multi-centre, randomized, double-blind trial started on November 22, 2012, in China. In total, 7372 eligible women aged 18-45 years were age-stratified and randomly assigned to receiving 3 doses of the test or control (hepatitis E) vaccine at months 0, 1 and 6. Co-primary endpoints included high-grade genital lesions and persistent infection (over 6 months) associated with HPV-16/18. The primary analysis was performed on a per-protocol susceptible population of individuals who were negative for relevant HPV type-specific neutralizing antibodies (at day 0) and DNA (at day 0 through month 7) and who received 3 doses of the vaccine. This report presents data from a pre-specified interim analysis used for regulatory submission. Results In the per-protocol cohort, the efficacies against high-grade genital lesions and persistent infection were 100.0% (95% confidence interval [CI] = 55.6% to 100.0%, 0/3306 in the vaccine group vs. 10/3296 in the control group) and 97.8% (95% CI = 87.1% to 99.9%, 1/3240 vs. 45/3246), respectively. The side effects were mild. No vaccine-related serious adverse events were noted. Robust antibody responses for both types were induced and persisted for at least 42 months. Conclusions The Escherichia coli-produced HPV-16/18 vaccine is well tolerated and highly efficacious against HPV-16/18 associated high-grade genital lesions and persistent infection in women.This work was supported by grants from the Chinese National High-tech R&D Program (863 program, 2012AA02A408), the Chinese National Major Scientific and Technological Special Project for “Significant New Drug Development” (2018ZX09308010 and 2012ZX09101316), the National Natural Science Foundation of China (81673240 and U1705283), the Fujian Provincial Major Scientific and Technological Project (2015YZ0002), the Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences (CIFMS, 2017-I2M-B&R-03, and 2016-I2M-1-019) and Xiamen Innovax. 该研究获得了国家高技术研究发展计划(863计划)、新药创制国家科技重大专项、国家自然科学基金、福建省科技重大专项、中国医学科学院医学与健康科技创新工程基金以及厦门万泰沧海生物技术有限公司的资助

    Search for the decay J/ψγ+invisibleJ/\psi\to\gamma + \rm {invisible}

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    We search for J/ψJ/\psi radiative decays into a weakly interacting neutral particle, namely an invisible particle, using the J/ψJ/\psi produced through the process ψ(3686)π+πJ/ψ\psi(3686)\to\pi^+\pi^-J/\psi in a data sample of (448.1±2.9)×106(448.1\pm2.9)\times 10^6 ψ(3686)\psi(3686) decays collected by the BESIII detector at BEPCII. No significant signal is observed. Using a modified frequentist method, upper limits on the branching fractions are set under different assumptions of invisible particle masses up to 1.2  GeV/c2\mathrm{\ Ge\kern -0.1em V}/c^2. The upper limit corresponding to an invisible particle with zero mass is 7.0×107\times 10^{-7} at the 90\% confidence level

    Bioaccumulation and Toxicity of Organic Chemicals in Terrestrial Invertebrates

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    Terrestrial invertebrates are key components in ecosystems, with crucial roles in soil structure, functioning, and ecosystem services. The present chapter covers how terrestrial invertebrates are impacted by organic chemicals, focusing on up-to-date information regarding bioavailability, exposure routes and general concepts on bioaccumulation, toxicity, and existing models. Terrestrial invertebrates are exposed to organic chemicals through different routes, which are dependent on both the organismal traits and nature of exposure, including chemical properties and media characteristics. Bioaccumulation and toxicity data for several groups of organic chemicals are presented and discussed, attempting to cover plant protection products (herbicides, insecticides, fungicides, and molluscicides), veterinary and human pharmaceuticals, polycyclic aromatic compounds, polychlorinated biphenyls, flame retardants, and personal care products. Chemical mixtures are also discussed bearing in mind that chemicals appear simultaneously in the environment. The biomagnification of organic chemicals is considered in light of the consumption of terrestrial invertebrates as novel feed and food sources. This chapter highlights how science has contributed with data from the last 5 years, providing evidence on bioavailability, bioaccumulation, and toxicity derived from exposure to organic chemicals, including insights into the main challenges and shortcomings to extrapolate results to real exposure scenarios
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