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Root Secretion of Phytochemicals in Arabidopsis Is Predominantly Not Influenced by Diurnal Rhythms

Molecular Plant 2010年第3期3卷 491-498页

作者： Dayakar v. Badri victor M. Loyola-vargas Corey D. Broeckling Jorge M. vivanco Center for Rhizosphere Biology Colorado State University Fort Collins CO 80523 USA 30 Col. Chuburna de Hidalgo Merida Yucatan Mexico

Root-secreted phytochemicals mediate multiple interactions in the rhizosphere. The root exudation process can be altered by various biotic factors, including pathogenic and non-pathogenic microbes, and abiotic factors like temperature and soil moisture. It has been suggested that root secretion of specific flavonoids is influenced by diurnal rhythms （by light or dark） but a comprehensive analysis of the overall secretion of phytochemicals in response to diurnal rhythms has not been studied. In this study, we analyzed the effect of light/dark cycles on root exudation profiles using Arabidopsis as a model plant. Our results reveal that the root secretion of phytochemicals is partly regulated by the diurnal light cycle and follows two main patterns of secretion：（1） the large majority of phytochemicals in the exudates showed no diurnal pattern in their secretion, and （2） a few compounds showed a diurnal pattern in their secretion： three compounds increased in secretion only under light; two compounds increased in secretion only while it was dark; and two compounds increased in secretion during the transition from dark to light. Root-specific ABC transporters have been implicated in root exudation; an analysis of the gene expression patterns of ABC transporters in the roots of Arabidopsis at specific time points revealed that none of the ABC transporters followed a diurnal expression pattern, suggesting that they are expressed constantly during the day and night. Similarly, we analyzed the expression in roots of genes involved in secondary metabolite biosynthesis and found that some of the genes involved in phenylpropanoid and glucosinolate biosynthesis （i.e. 4-coumarate-CoA ligases （4CL1 and 4CL2）, flavonol synthases （FSl and FS2）, and CYP79B3） followed distinct diurnal expression patterns. Overall, we have discovered that while root exudation of the majority of phytochemicals is constitutive, the secretion of a few compounds follows a diurnal rhythm, which is in accor

关键词： Arabidopsis diurnal rhythm root exudates ABC transporters secondary metabolite biosynthesis.

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Genetic structure of the Amur tiger(Panthera tigris altaica)population:Are tigers in Sikhote-Alin and southwest Primorye truly isolated?

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Integrative Zoology 2016年第1期11卷 25-32页

作者： Pavel A.SOROKIN vyatcheslav v.ROZHNOv Anna U.KRASNENKO victor S.LUKAREvSKIY Sergey v.NAIDENKO Jose A.HERNANDEZ-BLANCO A.N.Severtsov Institute of Ecology and Evolution Russian Academy of SciencesMoscowRussia

We used molecular genetic analyses to noninvasively identify individual Amur tigers and define subpopulations of tigers in the Russian Far *** identified 63 individuals after genotyping 256 feces,7 hair and 11 blood samples collected within southern,central and northern Sikhote-Alin,as well as Southwest *** of nuclear DNA at 9 microsatellite loci demonstrated greater genetic similarity between animals from southern and northern Sikhote-Alin(some 500 km apart)than between animals from Ussuriskii State Nature Reserve and Southwest Primorye(less than 10 km apart at their nearest point),suggesting that a true barrier exists preventing movements of tigers between Southwest Primorye and the southern Sikhote-Alin Mountains.

关键词： Amur tiger fecal DNA noninvasive genetic sampling Panthera tigris altaica

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MXene supported surface plasmons on telecommunications optical fibers

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Light(Science & Applications) 2022年第2期11卷 212-220页

作者： victor Pacheco-Peña Toby Hallam Noel Healy School of Mathematics Statistics and PhysicsNewcastle UniversityNewcastle Upon Tyne NE17RUUK

MXenes,an emerging class of two-dimensional materials,exhibit characteristics that promise significant potential for their use in next generation optoelectronic *** interplay between interband transitions and boundary effects offer the potential to tune the plasma frequencies over a large spectral range from the near-infrared to the *** tuneability along with the‘layered’nature of the material not only offer the flexibility to produce plasmon resonances across a wide range of wavelengths,but also add a degree of freedom to the sensing mechanism by allowing the plasma frequency to be *** we show,numerically,that MXenes can support plasmons in the telecommunications frequency range and that surface plasmon resonances can be excited on a standard MXene coated side polished optical ***,presenting the tantalising prospect of highly selective distributed optical fiber sensor networks.

关键词： fibers excited transitions

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Epstein-Barr virus:Silent companion or causative agent of chronic liver disease?

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World Journal of Gastroenterology 2010年第33期16卷 4130-4134页

作者： Mihaela petrova victor Kamburov Clinic of Gastroenterology Ministry of Interior Gastroenterology Division First Multiprofile Hospital for Active Treatment

The Epstein-Barr virus(EBv)has an important and multifaceted role in liver *** a member of the herpes virus family,EBv establishes a persistent infection in more than 90%of *** acute hepatitis during primary infection,many clinical syndromes of interest for the hepatologist are associated with EBv *** role of EBv in the evolution of chronic hepatitis from hepatotropic viruses is *** EBvassociated hepatitis is suspected in immunocompetent adults with compatible serology,suggestive histology and detection of the viral genome in the liver and/or increase of specific circulating cytotoxic *** is the main cause of post-transplant lymphoproliferative disorders which occur in up to 30%of ***-driven lymphoproliferative diseases are also recognized in non-immunocompromised patients and liver is involved in up to a third of the *** implicated in the pathogenesis of different tumors,EBv has a disputable role in hepatocellular carcinoma *** research is required in order to establish or reject the role of EBv in human liver *** paper attempts to discuss the range of EBv-associated chronic liver diseases in immunocompetent patients,from mild,self-limiting mononuclear hepatitis to liver cancer.

关键词： Epstein-Barr virus Chronic hepatitis Liver disease Chronic active Epstein-Barr virus Post-transplant lymphoproliferative disorder Infectious mononucleosis

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Breastfeeding and chronic HBv infection: Clinical and social implications

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World Journal of Gastroenterology 2010年第40期16卷 5042-5046页

作者： Mihaela petrova victor Kamburov Clinic of Gastroenterology Ministry of Interior Department of Gastroenterology First Multi Profile Hospital for Active Treatment

Mother-to-child transmission of hepatitis B virus (HBv) is among the most important causes of chronic HBv infection and is the commonest mode of transmission worldwide. Currently, the presence of HBsAg, HBeAg and HBv DNA in breast milk is confirmed. Several studies have reported that breastfeeding carries no additional risk that might lead to vertical transmission. Beyond some limitations, the surveys have not demonstrated any differences in HBv transmission rate regarding feeding practices in early childhood. Promotion of breastfeeding is substantial, especially for low-income individuals and regions with uncertain, unfeasible, and unsafe water supplies. Lactoferrin, minimal inflammation or activation within the infant gut during exclusive breastfeeding, and nonspecific biological molecules in the milk are identified as major factors of breast-milk defense. This review discusses preemptive antiviral therapy during pregnancy and lactation. Long-term follow up of breast-milk HBv concentrations and correlation with serum viral load; nucleos(t)ide analogue concentrations in breast milk in HBv-positive mothers in the setting of chronic HBv infection; safety of antiviral therapy during pregnancy and lactation; and the difference in viral load in the milk in exclusive or non-exclusive breastfeeding are still open questions. The paper reviews the current data and outlines the course of further investigation into this often underestimated issue.

关键词： Breastfeeding Lamivudine Tenofovir Hepatitis B virus Chronic hepatitis B

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The Cretaceous Turn of Geological Evolution: Key Evidence from East Asia

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Acta Geologica Sinica(English Edition) 2018年第5期92卷 1991-2003页

作者： victor P.NECHAEv DAI Shifeng F.Lin SUTHERLAND Ian T.GRAHAM Eugenia v.NECHAEvA Far East Geological Institute Far Eastern Branch Russian Academy of Sciences Engineering School Far Eastern Federal University State Key Laboratory of Coal Resources and Safe Mining China University of Mining and Technology School of Resources and Geosciences China University of Mining and Technology Geoscience Australian Museum PANGEA Research Centre School of Biological Earth and Environmental Sciences University of New South Wales

this work focuses on one of the critical points of Earth＇s history when the Solar System passed through the most distant point of its galactic orbit. During this event, Earth may have suffered from maximum extension, associated with its relative proximity to the Sun at that time, followed by long-term contraction related to its later distancing. This paper is based on generalized data on the Cretaceous evolution of the Earth as a whole and of East Asia in particular. The evidence suggests that major geological processes at this time may be interpreted as transitional changes in the state of Earth. A liquid nature of its core may have reacted to the gravitational and electromagnetic transformations. When the cosmic changes took place at 135-120 Ma, more turbulent flows in the outer core would have favoured the rise of voluminous magmatic plumes and associated fluid flows. These would substantially transform the mantle, crust, hydrosphere, biosphere and atmosphere. In particular, plume-related melting of overlying subducting slabs and lower continental crust could have initiated numerous adakitic melts that formed the East Asian Adakitic Province. These and associated juvenile events produced numerous metallic ore, coal, gas and oil deposits. The Cretaceous is one of the most significant resource-producing periods.

关键词： Cretaceous geological evolution galactic orbit super plume adakitic rocks coal ore and petroleum resources

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Investigation of WZ Sge-type Dwarf Nova ASASSN-19oc:Optical Spectroscopy and Multicolor Light Curve Analysis

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Research in Astronomy and Astrophysics 2024年第8期24卷 20-31页

作者： viktoriia Krushevska Sergey Shugarov Paolo Ochner Yuliana Kuznyetsova Mykola petrov Peter Kroll Astronomical Institute of the Slovak Academy of Sciences Tatranska Lomnica05960 VysokéTatrySlovakia Main Astronomical Observatory of NAS of Ukraine 27 Akademika Zabolotnoho St.03143 KyivUkraine INAF—Osservatorio Astronomico di Padova Vicolo dell’Osservatorio 5I-35122 PadovaItaly Department of Physics and Astronomy University of PadovaVia F.Marzolo 8I-35131 PadovaItaly Max Planck Computing and Data Facility(MPCDF) Gießenbachstrasse 2D-85748 GarchingGermany Sonneberg Observatory Sternwartestr.32D-96515 SonnebergGermany

In this study,we present an investigation of the newly discovered dwarf nova ASASSN-19oc during its superoutburst on 2019 June *** carried out detailed UBvRcIc-photometric observations and also obtained a spectrum on day 7 of the outburst,which shows the presence of hydrogen absorption lines commonly found in dwarf nova *** of photometric data reveals the occurrence of early superhumps in the initial days of observations,followed by ordinary and late *** have accurately calculated the period of the ordinary superhumps as Pord=0.05681(10)days and determined the periods at different stages,as well as the rate of change of the superhump period(P_(dot)=(5)P/P=8.1×10^(-5)).Additionally,we have derived the mass ratio of the components(q=0.09),and estimated the color temperature during the outburst as~11,000 K,the distance to the system(d=560 pc)and absolute magnitude of the system in outburst(Mv=5.3).We have shown that outbursts of this star are very rare:based on brightness measurements on 600 archival photographic plates,we found only one outburst that occurred in *** fact,as well as the properties listed above,convincingly shows that the variable ASASSN-19oc is a dwarf nova of WZ Sge type.

关键词： (stars)binaries(including multiple) close-(stars)novae-cataclysmic variables-stars dwarf novae

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Immune evasion strategies used by Helicobacter pylori

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World Journal of Gastroenterology 2014年第36期20卷 12753-12766页

作者： Taslima T Lina Shatha Alzahrani Jazmin Gonzalez Irina v Pinchuk Ellen J Beswick victor E Reyes Department of Microbiology and Immunology University of Texas Medical Branch Galveston TX 77555 United States MS-III School of Medicine University of Texas Medical Branch Galveston TX 77555 United States Department of Internal Medicine University of Texas Medical Branch Galveston TX 77555 United States Departments of Molecular Genetics and Microbiology University of New Mexico Health Sciences Center Albuquerque NM 87131 United States Departments of Pediatrics and Microbiology and Immunology University of Texas Medical Branch Galveston TX 77555 United Statest

Helicobacter pylori(H. pylori) is perhaps the most ubiquitous and successful human pathogen, since it colonizes the stomach of more than half of humankind. Infection with this bacterium is commonly acquired during childhood. Once infected, people carry the bacteria for decades or even for life, if not treated. Persistent infection with this pathogen causes gastritis, peptic ulcer disease and is also strongly associated with the development of gastric cancer. Despite induction of innate and adaptive immune responses in the infected individual, the host is unable to clear the bacteria. One widely accepted hallmark of H. pylori is that it successfully and stealthily evades host defense mechanisms. Though the gastric mucosa is well protected against infection, H. pylori is able to reside under the mucus, attach to gastric epithelial cells and cause persistent infection by evading immune responses mediated by host. In this review, we discuss how H. pylori avoids innate and acquired immune response elements, uses gastric epithelial cells as mediators to manipulate host T cell responses and uses virulence factors to avoid adaptive immune responses by T cells to establish a persistent infection. We also discuss in this review how the genetic diversity of this pathogen helps for its survival.

关键词： Helicobacter pylori Immune response Pattern recognition receptors Phagocytes T cells Antigen presenting cells Gastric epithelial cells vacuolating cytotoxin T4SS

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Effect of Helicobacter pylori on gastric epithelial cells

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World Journal of Gastroenterology 2014年第36期20卷 12767-12780页

作者： Shatha Alzahrani Taslima T Lina Jazmin Gonzalez Irina v Pinchuk Ellen J Beswick victor E Reyes Department of Microbiology and Immunology University of Texas Medical Branch Galveston TX 77555 United States MSIII School of Medicine University of Texas Medical Branch Galveston TX 77555 United States Department of Internal Medicine University of Texas Medical Branch Galveston TX 77555 United States Departments of Molecular Genetics and Microbiology University of New Mexico Health Sciences Center Albuquerque NM 87131 United States Departments of Pediatricsand and Microbiology and Immunology University of Texas Medical Branch Galves-ton TX 77555 United States

The gastrointestinal epithelium has cells with features that make them a powerful line of defense in innate mucosal immunity. Features that allow gastrointestinal epithelial cells to contribute in innate defense include cell barrier integrity, cell turnover, autophagy, and innate immune responses. Helicobacter pylori (H. pylori) is a spiral shape gram negative bacterium that selectively colonizes the gastric epithelium of more than half of the world’s population. The infection invariably becomes persistent due to highly specialized mechanisms that facilitate H. pylori’s avoidance of this initial line of host defense as well as adaptive immune mechanisms. The host response is thus unsuccessful in clearing the infection and as a result becomes established as a persistent infection promoting chronic inflammation. In some individuals the associated inflammation contributes to ulcerogenesis or neoplasia. H. pylori has an array of different strategies to interact intimately with epithelial cells and manipulate their cellular processes and functions. Among the multiple aspects that H. pylori affects in gastric epithelial cells are their distribution of epithelial junctions, DNA damage, apoptosis, proliferation, stimulation of cytokine production, and cell transformation. Some of these processes are initiated as a result of the activation of signaling mechanisms activated on binding of H. pylori to cell surface receptors or via soluble virulence factors that gain access to the epithelium. The multiple responses by the epithelium to the infection contribute to pathogenesis associated with H. pylori.

关键词： Helicobacter pylori Apoptosis Gastric epithelial cells Proinflammatory cytokines Chronic inflammation Gastric diseases Gastric cancer

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Identifying ecological corridors for Amur tigers(Panthera tigris altaica)and Amur leopards(Panthera pardus orientalis)

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Integrative Zoology 2015年第4期10卷 389-402页

作者： Dale G.MIQUELLE vyachaslav v.ROZHNOv victor ERMOSHIN Andre A.MURZIN Igor G.NIKOLAEv Jose A.HERNANDEZ-BLANCO Sergie v.NAIDENKO Wildlife Conservation Society BronxNew YorkUSA A.N.Severtsov Institute of Ecology and Evolution Russian Academy of SciencesMoscowRussia Pacific Institute of Geography Far Eastern Branch of the Russian Academy of SciencesVladivostokRussia The Institute of Biology and Soils Far Eastern Branch of the Russian Academy of SciencesVladivostokRussia

The rapid explosion of human populations and the associated development of human-dominated landscapes have drastically reduced and fragmented habitat for tigers(Panthera tigris)and leopards(Panthera pardus)across Asia,resulting in multiple small ***,Amur tiger(Panthera tigris altaica)habitat in Russia has remained largely interconnected,except for a break between tigers in southwest Primorye and the southern Sikhote-Alin *** habitat patch in southwest Primorye also retains the last population of Amur leopards(Panthera pardus orientalis).Genetic differentiation of tigers in southwest Primorye and the Sikhote-Alin Mountains along with survey data suggest that habitat fragmentation is limiting movement of tigers and leopards across the Razdolnaya River *** looked at historical and recent survey data on tigers and leopards and mapped existing cover types to examine land-use patterns of both large felids and humans in the development strip along the Razdolnaya *** then used least-cost distance analyses to identify the most effective potential corridor to retain connectivity for large felids between Land of the Leopard National Park and Ussuriskii Zapovednik(Reserve).We identified a single potential corridor that still exists with a total distance of 62.5 km from Land of the Leopard National Park to Ussuriskii Zapovednik,mostly(93%)through forested *** recommend formal recognition of a Razdolnaya ecological corridor and provide specific recommendations for each of 3 proposed management sections.

关键词： Amur tiger ecological corridor Sikhote-Alin Mountains

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