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51.
Pandrea I Ribeiro RM Gautam R Gaufin T Pattison M Barnes M Monjure C Stoulig C Dufour J Cyprian W Silvestri G Miller MD Perelson AS Apetrei C 《Journal of virology》2008,82(7):3713-3724
The mechanisms underlying the lack of disease progression in natural simian immunodeficiency virus (SIV) hosts are still poorly understood. To test the hypothesis that SIV-infected African green monkeys (AGMs) avoid AIDS due to virus replication occurring in long-lived infected cells, we infected six animals with SIVagm and treated them with potent antiretroviral therapy [ART; 9-R-(2-phosphonomethoxypropyl) adenine (tenofovir) and beta-2,3-dideoxy-3-thia-5-fluorocytidine (emtricitabine)]. All AGMs showed a rapid decay of plasma viremia that became undetectable 36 h after ART initiation. A significant decrease of viral load was observed in peripheral blood mononuclear cells and intestine. Mathematical modeling of viremia decay post-ART indicates a half-life of productively infected cells ranging from 4 to 9.5 h, i.e., faster than previously reported for human immunodeficiency virus and SIV. ART induced a slight but significant increase in peripheral CD4(+) T-cell counts but no significant changes in CD4(+) T-cell levels in lymph nodes and intestine. Similarly, ART did not significantly change the levels of cell proliferation, activation, and apoptosis, already low in AGMs chronically infected with SIVagm. Collectively, these results indicate that, in SIVagm-infected AGMs, the bulk of virus replication is sustained by short-lived cells; therefore, differences in disease outcome between SIVmac infection of macaques and SIVagm infection of AGMs are unlikely due to intrinsic differences in the in vivo cytopathicities between the two viruses. 相似文献
52.
Pandrea I Gaufin T Brenchley JM Gautam R Monjure C Gautam A Coleman C Lackner AA Ribeiro RM Douek DC Apetrei C 《Journal of immunology (Baltimore, Md. : 1950)》2008,181(10):6687-6691
Chronically SIVagm-infected African green monkeys (AGMs) have a remarkably stable nonpathogenic disease course, with levels of immune activation in chronic SIVagm infection similar to those observed in uninfected monkeys and with stable viral loads for long periods of time. In vivo administration of LPS or an IL-2/diphtheria toxin fusion protein (Ontak) to chronically SIVagm-infected AGMs triggered increases in immune activation and subsequently of viral replication and depletion of intestinal CD4(+) T cells. Our study indicates that circulating microbial products can increase viral replication by inducing immune activation and increasing the number of viral target cells, thus demonstrating that immune activation and T cell proliferation are key factors in AIDS pathogenesis. 相似文献
53.
In vitro translation of exogenous mRNAs has been difficult to achieve using chloroplast components. An in vitro protein synthesis system is described, based on a pea ( Pisum sativum L, cv. Spring) chloroplast stroma 30000 g supernatant, which was capable of translating polyuridylie acid and MS2 phage RNA into corresponding proteins. The kinetics of label incorporation and fluorograms of unique translation products are presented. The unusual steps which may have contributed to successful translation include the following: the removal of exogenous unlabeled amino acids from the incubation mixture, ultrafiltration of the stromal supernatant and the removal of thylakoid-bound polyribosomes. The system could be further developed to study translational control of gene expression in the chloroplasts. 相似文献
54.
I. Mladineo 《Zeitschrift fur angewandte Ichthyologie》2003,19(6):366-370
Owing to its quickness and sensitivity, and the minimal financial effort required, immunohistochemistry is a leading technique for nodavirus diagnosis. The aim of the study was to give detailed results of immunohistochemical changes in the various tissues of larvae, juvenile and adult sea bass (Dicentrarchus labrax L.). Histological sections were treated with polyclonal anti‐noda rabbit IgG, while diaminobenzidine‐peroxidase was used for the enzyme–substrate complex. The development from first changes to vacuolating necrosis was recorded in the brain, spinal cord and retina. For the first time, immunolabelling was noted in the liver endothelium. The other sampled tissue was immunonegative. 相似文献
55.
Dongzhu Ma Anna J. Jasinska Felix Feyertag Viskam Wijewardana Jan Kristoff Tianyu He Kevin Raehtz Christopher A. Schmitt Yoon Jung Jennifer Danzy Cramer Michel Dione Martin Antonio Russell Tracy Trudy Turner David L. Robertson Ivona Pandrea Nelson Freimer Cristian Apetrei 《Journal of virology》2014,88(10):5687-5705
56.
Petra Procházková Schrumpfová Ivona Vychodilová Martina Dvořáčková Jana Majerská Ladislav Dokládal Šárka Schořová Jiří Fajkus 《The Plant journal : for cell and molecular biology》2014,77(5):770-781
Although telomere‐binding proteins constitute an essential part of telomeres, in vivo data indicating the existence of a structure similar to mammalian shelterin complex in plants are limited. Partial characterization of a number of candidate proteins has not identified true components of plant shelterin or elucidated their functional mechanisms. Telomere repeat binding (TRB) proteins from Arabidopsis thaliana bind plant telomeric repeats through a Myb domain of the telobox type in vitro, and have been shown to interact with POT1b (Protection of telomeres 1). Here we demonstrate co‐localization of TRB1 protein with telomeres in situ using fluorescence microscopy, as well as in vivo interaction using chromatin immunoprecipitation. Classification of the TRB1 protein as a component of plant telomeres is further confirmed by the observation of shortening of telomeres in knockout mutants of the trb1 gene. Moreover, TRB proteins physically interact with plant telomerase catalytic subunits. These findings integrate TRB proteins into the telomeric interactome of A. thaliana. 相似文献
57.
Tissue encapsulation, one of the most common tissue reactions to invading parasites, is the hallmark sign of didymozoid (Digenea, Didymozoidae) infections in fish. Investigated were the types of intermediate filaments and ultrastructure of the connective tissue capsule elicited by the presence of didymozoids in the gills and intestine of Atlantic bluefin tuna (Thunnus thynnus Linnaeus, 1758). The evaluation was done performing TEM microscopy of two tissue‐embedded didymozoid species, along with monoclonal antibodies labeling (anti‐fish collagen type I, anti‐human cytokeratin, anti‐vimentin antibodies). Ultrastructure of Didymocystis wedli (Ariola, 1902) (prevalence = 61.75%, abundance = 28.91) encapsulated in gill filaments and Koellikerioides intestinalis ( Yamaguti, 1970 ) (prevalence = 54.65%, abundance = 10.96) in the intestinal submucosa showed that the thin parasitic hindbody tegumentum was directly embedded in layers of connective tissue bands. Only a few cellular elements (lymphocytes, fibroblasts and fibrocytes) infiltrated the connective tissue capsule, which differed between the two didymozoid species in thickness, not in the type of filaments expressed. Cysts showed positive reaction to extracellular collagen as well as appearing positive for the cytoskeletal intermediate filaments vimentin and cytokeratin. 相似文献
58.
Smith EJ Allantaz F Bennett L Zhang D Gao X Wood G Kastner DL Punaro M Aksentijevich I Pascual V Wise CA 《Current Genomics》2010,11(7):519-527
PAPA syndrome (Pyogenic Arthritis, Pyoderma gangrenosum, and Acne) is an autosomal dominant, hereditary auto-inflammatory disease arising from mutations in the PSTPIP1/CD2BP1 gene on chromosome 15q. These mutations produce a hyper-phosphorylated PSTPIP1 protein and alter its participation in activation of the "inflammasome" involved in interleukin-1 (IL-1β) production. Overproduction of IL-1β is a clear molecular feature of PAPA syndrome. Ongoing research is implicating other biochemical pathways that may be relevant to the distinct pyogenic inflammation of the skin and joints characteristic of this disease. This review summarizes the recent and rapidly accumulating knowledge on these molecular aspects of PAPA syndrome and related disorders. 相似文献
59.
Nichole R. Klatt Emi Shudo Alex M. Ortiz Jessica C. Engram Mirko Paiardini Benton Lawson Michael D. Miller James Else Ivona Pandrea Jacob D. Estes Cristian Apetrei Joern E. Schmitz Ruy M. Ribeiro Alan S. Perelson Guido Silvestri 《PLoS pathogens》2010,6(1)
While CD8+ T cells are clearly important in controlling virus replication during HIV and SIV infections, the mechanisms underlying this antiviral effect remain poorly understood. In this study, we assessed the in vivo effect of CD8+ lymphocyte depletion on the lifespan of productively infected cells during chronic SIVmac239 infection of rhesus macaques. We treated two groups of animals that were either CD8+ lymphocyte-depleted or controls with antiretroviral therapy, and used mathematical modeling to assess the lifespan of infected cells either in the presence or absence of CD8+ lymphocytes. We found that, in both early (day 57 post-SIV) and late (day 177 post-SIV) chronic SIV infection, depletion of CD8+ lymphocytes did not result in a measurable increase in the lifespan of either short- or long-lived productively infected cells in vivo. This result indicates that the presence of CD8+ lymphocytes does not result in a noticeably shorter lifespan of productively SIV-infected cells, and thus that direct cell killing is unlikely to be the main mechanism underlying the antiviral effect of CD8+ T cells in SIV-infected macaques with high virus replication. 相似文献
60.
Dongzhu Ma Anna Jasinska Jan Kristoff J. Paul Grobler Trudy Turner Yoon Jung Christopher Schmitt Kevin Raehtz Felix Feyertag Natalie Martinez Sosa Viskam Wijewardana Donald S. Burke David L. Robertson Russell Tracy Ivona Pandrea Nelson Freimer Cristian Apetrei The International Vervet Research Consortium 《PLoS pathogens》2013,9(1)
Pathogenesis studies of SIV infection have not been performed to date in wild monkeys due to difficulty in collecting and storing samples on site and the lack of analytical reagents covering the extensive SIV diversity. We performed a large scale study of molecular epidemiology and natural history of SIVagm infection in 225 free-ranging AGMs from multiple locations in South Africa. SIV prevalence (established by sequencing pol, env, and gag) varied dramatically between infant/juvenile (7%) and adult animals (68%) (p<0.0001), and between adult females (78%) and males (57%). Phylogenetic analyses revealed an extensive genetic diversity, including frequent recombination events. Some AGMs harbored epidemiologically linked viruses. Viruses infecting AGMs in the Free State, which are separated from those on the coastal side by the Drakensberg Mountains, formed a separate cluster in the phylogenetic trees; this observation supports a long standing presence of SIV in AGMs, at least from the time of their speciation to their Plio-Pleistocene migration. Specific primers/probes were synthesized based on the pol sequence data and viral loads (VLs) were quantified. VLs were of 104–106 RNA copies/ml, in the range of those observed in experimentally-infected monkeys, validating the experimental approaches in natural hosts. VLs were significantly higher (107–108 RNA copies/ml) in 10 AGMs diagnosed as acutely infected based on SIV seronegativity (Fiebig II), which suggests a very active transmission of SIVagm in the wild. Neither cytokine levels (as biomarkers of immune activation) nor sCD14 levels (a biomarker of microbial translocation) were different between SIV-infected and SIV-uninfected monkeys. This complex algorithm combining sequencing and phylogeny, VL quantification, serology, and testing of surrogate markers of microbial translocation and immune activation permits a systematic investigation of the epidemiology, viral diversity and natural history of SIV infection in wild African natural hosts. 相似文献