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Degradation of black tea theaflavin through C-ring cleavage by gut microbiota

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Food Science and Human Wellness 2022年第3期11卷 598-605页

作者： Shuwei Zhang christina Ohland Christian Jobin Shengmin Sang Laboratory for Functional Foods and Human Health Center for Excellence in Post-Harvest TechnologiesNorth Carolina Agricultural and Technical State UniversityNorth Carolina Research CampusKannapolisNorth Carolina 28081USA Department of Medicine University of FloridaGainesvilleFlorida 32611USA Department of Infectious Diseases and Immunology University of FloridaGainesvilleFlorida 32611USA

Increasing evidence has shown that gut microbiota plays important roles in metabolizing large molecular polyphenols to bioavailable and bioactive microbial ***(TF)is one of the major color compounds in black tea and has demonstrated anti-inflammation,antioxidant,and anticancer effects ***,little is known about the metabolism of TF by gut microbiota in *** this study,following the administration of TF to mice,the C-ring cleavage metabolites,dihydro-and tetrahydro-theaflavin(DH-TF and TH-TF)were detected in mouse feces by LC-MS and validated by authentic standards from in situ chemical *** observation of the C-ring cleavage metabolites in TF-treated conventionalized mice but not in germ-free(GF)mice confirmed the role of gut microbiota in cleaving the C-rings of *** detection of DH-TF from the anaerobic incubation of TF with catechin-converting gut bacteria,Eggerthella lenta(Eggerth),suggested that the microbes with the capacity to cleave the C-ring of catechins were able to metabolize TF following the same ***,three small phenolic metabolites were detected in mouse feces,and one of them was primarily detected in SPF mice not GF mice,which revealed that TF,subsequent to the cleaved C-ring,can be further metabolized into smaller phenolic metabolites by gut ***-dependent production of these metabolites were observed from the administration of 100 mg/kg to 400 mg/kg body weight of *** conclusion,gut microbiota can metabolize TF to the open-ring metabolites and the phenolic metabolites through the C-ring cleavage in mice.

关键词： Theaflavin Black tea C-ring cleavage Anaerobic incubation Germ-free mice

Preservation of nucleic acids by freeze-drying for next generation sequencing analyses of soil microbial communities

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Journal of Plant Ecology 2017年第1期10卷 81-90页

作者： christina Weißbecker François Buscot Tesfaye Wubet Department of Soil Ecology UFZ—Helmholtz Centre for Environmental ResearchTheodor-Lieser-Straße 406120 Halle(Saale)Germany Institute of Biology University of LeipzigJohannis-Allee 3-504103 LeipzigGermany German Centre for Integrative Biodiversity Research(iDiv)Jena-Halle-Leipzig Deutscher Platz 5e04103 LeipzigGermany

Aims Soil sample preservation is a challenging aspect in molecular studies on soil microbial *** demands for specialized sample storage equipment,chemicals and standardized protocols for nucleic acid extraction often require sample processing in a home laboratory that can be continents apart from sampling *** sampling procedures,especially when dealing with RNA,comprise immediate snap freezing of soils in liquid nitrogen and storage at−80℃until further *** these instances,organizing a reliable cooling chain to transport hundreds of soil samples between continents is very costly,if possible at *** this study we tested the effect of soil sample preservation by freeze-drying with subsequent short-term storage at 4℃or ambient temperatures compared to−80℃freezing by comparative barcoding analyses of soil microbial *** Two grassland soil samples were collected in Central Germany in the Biodiversity Exploratory Hainich-Dü*** were freeze-dried or stored at−80℃as ***-dried samples were stored at 4℃or ambient *** storage times for both storage temperatures were 1 and 7 *** DNA and RNA were extracted and bacterial and arbuscular mycorrhizal(AM)fungal communities were analyzed by amplicon 454 pyrosequencing of the 16S(V4-V5 variable region)and 18S(NS31-AM1 fragment)of ribosomal RNA(rRNA)marker genes,*** Findings Bacterial communities were sufficiently well preserved at the rDNA and rRNA level although storage effects showed as slightly decreased alpha diversity indices for the prolonged storage of freeze-dried samples for 7 *** fungal communities could be studied without significant changes at the rDNA and rRNA *** results suggest that proper sampling design followed by immediate freeze-drying of soil samples enables short-term transportation of soil samples across continents.

关键词： lyophilization soil preservation biodiversity microbial communities

Regulatory Micro RNA Networks:Complex Patterns of Target Pathways for Disease-related and Housekeeping MicroRNAs

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Genomics, Proteomics & Bioinformatics 2015年第3期13卷 159-168页

作者： Sachli Zafari christina Backes Petra Leidinger Eckart Meese Andreas Keller Chair for Clinical Bioinformatics Saarland UniversityUniversity Hospital Department of Human Genetics Saarland UniversityUniversity Hospital

Blood-based mieroRNA （miRNA） signatures as biomarkers have been reported for various pathologies, including cancer, neurological disorders, cardiovascular diseases, and also infections. The regulatory mechanism behind respective miRNA patterns is only partially understood. Moreover, ＂preserved＂ miRNAs, i.e., miRNAs that are not dysregulated in any disease, and their biological impact have been explored to a very limited extent. We set out to systematically determine their role in regulatory networks by defining groups of highly-dysregulated miRNAs that contribute to a disease signature as opposed to preserved housekeeping miRNAs. We further determined preferential targets and pathways of both dysregulated and preserved miRNAs by computing multi-layer networks, which were compared between housekeeping and dysregulated miRNAs. Of 848 miRNAs examined across 1049 blood samples, 8 potential housekeepers showed very limited expression variations, while 20 miRNAs showed highly-dysregulated expression throughout the investigated blood samples. Our approach provides important insights into miRNAs and their role in regulatory networks. The methodology can be applied to systematically investigate the differences in target genes and pathways of arbitrary miRNA sets.

关键词： miRNA miRNA targeting Systems biology Regulatory networks miRNA housekeepers

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小船在河上扬帆

初中生 2024年第6期 22-23页

作者：克里斯蒂娜·罗塞蒂不详

赏析克里斯蒂娜·罗塞蒂(christina Rosseti,1830-1894),英国女诗人。这是一首儿童诗,共两段,每双句押韵。全诗用词简单,每一句都是一幅清晰的简笔画。在每段结尾,诗人都表达了自己对大自然中美好事物的欣赏和赞叹。大小船只、修建的桥... 详细信息

赏析克里斯蒂娜·罗塞蒂(christina Rosseti,1830-1894),英国女诗人。这是一首儿童诗,共两段,每双句押韵。全诗用词简单,每一句都是一幅清晰的简笔画。在每段结尾,诗人都表达了自己对大自然中美好事物的欣赏和赞叹。大小船只、修建的桥梁,无论在河面和大海之上组成多么令人愉悦的画面,它们都无法与自然万物的美相比。

关键词：简笔画儿童诗女诗人自然万物

Comparing traveler preferences for BRT and LRT systems in developing countries:Evidence from Multan,Pakistan

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Journal of Traffic and Transportation Engineering(English Edition) 2020年第3期7卷 384-393页

作者： Konstantinos Kepaptsoglou christina Milioti Dimitra Spyropoulou Farhan Haider Aristeidis GKarlaftis School of Rural &Surveying Engineering National Technical University of AthensZografou 15780Greece Department of Transportation Engineering and Management University of Engineering and TechnologyLahorePakistan Senior Transportation Engineering Expert AthensGreece

Rapid transit(RT)systems are becoming increasingly attractive in the developing world as they improve transportation and mobility conditions in urban areas,reduce motorization impacts and offer high quality,yet cost effective services to *** rail transit(LRT)and bus rapid transit(BRT)are RT systems that combine high capacity with relatively low investment costs,and as such,they are preferred in developing countries over regular metro *** paper investigates traveler preferences over alternative,planned rapid transit options for the city of Multan,*** analysis is based on a household information survey with over 2300 questionnaires completed via personal *** to pay for improved PT services and choice between LRT and BRT systems are investigated,using appropriate econometric *** of this study can assist in better understanding the factors and their effect on choice between BRT and LRT in developing *** show that potential travelers,who prefer LRT are willing to pay more for better public transport *** the other hand,commuters and elders express a taste towards BRT *** on model outputs policy makers can develop targeted marketing policies in order to promote BRT/LRT implementation andattract candidate travelers from different groups,improving the possibility that users would support a BRT or LRT project.

关键词： Transportation engineering LRT BRT Binary logit model Traveler preferences

Role of the receptor for advanced glycation end products in hepatic fibrosis

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World Journal of Gastroenterology 2009年第46期15卷 5789-5798页

作者： christina Lohwasser Daniel Neureiter Yury Popov Michael Bauer Detlef Schuppan Department of Medicine Ⅰ University of Erlangen-NurembergErlangen-Nürnberg Institute of Pathology Paracelsus Private Medicine UniversitySalzburg Division of Gastroenterology Beth Israel Deaconess Medical CenterHarvard Medical SchoolBoston

AIM： To study the role of advanced glycation end products （AGE） and their specific receptor （RAGE） in the pathogenesis of liver fibrogenesis. METHODS： In vitro RAGE expression and extracellular matrix-related gene expression in both rat and human hepatic stellate cells （HSC） were measured after stimulation with the two RAGE ligands, advanced glycation end product-bovine serum albumin （AGE- BSA） and N＇-（carboxymethyl） lysine （CML）-BSA, or with tumor necrosis factor-α （TNF-α）. In vivo RAGE expression was examined in models of hepatic fibrosis induced by bile duct ligation or thioacetamide. The effects of AGE-BSA and CML-BSA on HSC proliferation, signal transduction and profibrogenic gene expression were studied in vitro. RESULTS： In hepatic fibrosis, RAGE expression was enhanced in activated HSC, and also in endothelial cells, inflammatory cells and activated bile duct epithelia. HSC expressed RAGE which was upregulated after stimulation with AGE-BSA, CML-BSA, and TNF-α.RAGE stimulation with AGE-BSA and CML-BSA did not alter HSC proliferation, apoptosis, fibrogenic signal transduction and fibrosis- or fibrolysis-related gene expression, except for marginal upregulation of procollagen α1（ I ） mRNA by AGE-BSA. CONCLUSION： Despite upregulation of RAGE in activated HSC, RAGE stimulation by AGE does not alter their fibrogenic activation. Therefore, RAGE does not contribute directly to hepatic fibrogenesis.

关键词： Advanced glycation end product Extracellularmatrix Hepatic stellate cell Matrix metalloproteinase Myofibroblast Receptor for advanced glycation endproducts Transforming growth factor β Tissue inhibitorof metalloproteinase Tumor necrosis factor α

Stochastic particle based models for suspended particle movement in surface flows

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International Journal of Sediment Research 2014年第2期29卷 195-207页

作者： christina W.TSAI Chuanjian MAN Jungsun OH Department of Civil Structural and Environmental EngineeringState University of New York at BuffaloBuffaloNY 14051USA Assoc.Prof. Department of Civil and Environmental Engineering National Taiwan University

Modeling of suspended sediment particle movement in surface water can be achieved by stochastic particle tracking model *** this paper,different mathematical forms of particle tracking models are introduced to describe particle movement under various flow conditions,i.e.,the stochastic diffusion process,stochastic jump process,and stochastic jump diffusion *** the stochastic diffusion process can be used to represent the stochastic movement of suspended particles in turbulent flows,the stochastic jump and the stochastic jump diffusion processes can be used to describe suspended particle movement in the occurrences of a sequence of extreme *** extreme flow herein is defined as a hydrologic flow event or a hydrodynamic flow phenomenon with a low probability of occurrence and a high impact on its ambient flow *** this paper,the suspended sediment particle is assumed to immediately follow the extreme flows in the jump process(*** time lag between the flow particle and the sediment particle in extreme flows is considered negligible).In the proposed particle tracking models,a random term mainly caused by fluid eddy motions is modeled as a Wiener process,while the random occurrences of a sequence of extreme flows can be modeled as a Poisson *** frequency of occurrence of the extreme flows in the proposed particle tracking model can be explicitly accounted for by the Poisson process when evaluating particle *** ensemble mean and variance of particle trajectory can be obtained from the proposed stochastic models via *** ensemble mean and variance of particle velocity are verified with available *** of the proposed stochastic particle tracking models for sediment transport modeling is also discussed.

关键词： Suspended sediment Particle tracking model Stochastic modeling Diffusion process Poisson jump process Jump diffusion process Extreme flows

Wetland Economic Valuation Approaches and Prospects in China

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Chinese Geographical Science 2016年第2期26卷 143-154页

作者： JIANG Bo christina P.WONG CUI Lijuan OUYANG Zhiyun State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China Changjiang Water Resources Protection Institute Wuhan 430051 China School of Sustainability Arizona State University Tempe AZ 85287 US.A Institute of Wetland Research Chinese Academy of Forestry Beijing 100091China

Ecosystem services valuation seeks to increase the social relevance of ecosystem characteristics, the underlying biological mechanisms that support services, by making the contribution of ecosystems to human well-being explicit. Economic valuation can help management by clarifying the full range of benefits and costs of proposed management actions. In the past two decades, economic valuation of wetland ecosystem services has become one of the most significant scientific priorities for wetland protection. In this paper, we provide an overview of ecosystem services, and summarize the main interdisciplinary approaches to measure and value wetland ecosystem services. We identified four main methodological gaps preventing progress on wetland valuation of ecosystem services in China, which are: 1) confusion on terminology like intermediate and final ecosystem services, 2) lack of ecological production functions to link ecosystem characteristics to final ecosystem services, 3) static valuation making it difficult to evaluate the trade-offs and synergies among ecosystem services, and 4) lack of clear guidance on relating ecological compensation programs to conservation targets. Overcoming these gaps is important to inform wetland compensation mechanisms and conservation policies. We propose future research on wetland ecosystem services in China should be focused on: 1) defining final ecosystem services based on beneficiary preferences and underlying biophysical mechanisms, 2) establishing wetland monitoring programs at specific sites to collect data on final ecosystem service indicators and ecosystem characteristic metrics to create ecological production functions for economic valuation and rescaling techniques, and 3) incorporating wetland ecosystem service values into decision-making processes to inform wetland management.

关键词： ecosystem services wetlands economic valuation methodological gaps China

Mouse models of colorectal cancer: Past, present and future perspectives

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World Journal of Gastroenterology 2020年第13期26卷 1394-1426页

作者： Florian Bürtin christina S Mullins Michael Linnebacher Department of General VisceralVascular and Transplantation SurgeryUniversity Medical Center RostockUniversity of RostockRostock 18057Germany Department of Thoracic Surgery University Medical Center RostockUniversity of RostockRostock 18057Germany Molecular Oncology and Immunotherapy Department of GeneralVisceralVascular and Transplantation SurgeryUniversity Medical Center RostockRostock 18057Germany

Colorectal cancer(CRC)is the third most common diagnosed malignancy among both sexes in the United States as well as in the European *** the incidence and mortality rates in western,high developed countries are declining,reflecting the success of screening programs and improved treatment regimen,a rise of the overall global CRC burden can be observed due to lifestyle changes paralleling an increasing human development *** a growing insight into the biology of CRC and many therapeutic improvements in the recent decades,preclinical in vivo models are still indispensable for the development of new treatment *** the development of carcinogen-induced rodent models for CRC more than 80 years ago,a plethora of animal models has been established to study colon cancer *** tenuous invasiveness and metastatic behavior,these models are useful for chemoprevention studies and to evaluate colitis-related *** engineered mouse models(GEMM)mirror the pathogenesis of sporadic as well as inherited CRC depending on the specific molecular pathways activated or *** the vast majority of CRC GEMM lack invasiveness,metastasis and tumor heterogeneity,they still have proven useful for examination of the tumor microenvironment as well as systemic immune responses;thus,supporting development of new therapeutic *** of metastatic disease by orthotopic injection of CRC cell lines is possible,but the so generated models lack genetic diversity and the number of suited cell lines is very ***-derived xenografts,in contrast,maintain the pathological and molecular characteristics of the individual patient's CRC after subcutaneous implantation into immunodeficient mice and are therefore most reliable for preclinical drug development–even in comparison to GEMM or cell line-based ***,subcutaneous patient-derived xenograft models are less suitable for studying most aspects of the tumor micr

关键词： Colorectal cancer Mouse models Patient-derived xenografts Carcinogen-induced models Genetically engineered mouse models Preclinical drug development