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排序方式: 共有713条查询结果,搜索用时 31 毫秒
621.
Amy Ziemba Spencer Hill Daniella Sandoval Kristofor Webb Eric J. Bennett Gary Kleiger 《The Journal of biological chemistry》2013,288(48):34882-34896
Together with ubiquitin ligases (E3), ubiquitin-conjugating enzymes (E2) are charged with the essential task of synthesizing ubiquitin chains onto protein substrates. Some 75% of the known E2s in the human proteome contain unique insertions in their primary sequences, yet it is largely unclear what effect these insertions impart on the ubiquitination reaction. Cdc34 is an important E2 with prominent roles in cell cycle regulation and signal transduction. The amino acid sequence of Cdc34 contains an insertion distal to the active site that is absent in most other E2s, yet this acidic loop (named for its four invariably conserved acidic residues) is critical for Cdc34 function both in vitro and in vivo. Here we have investigated how the acidic loop in human Cdc34 promotes ubiquitination, identifying two key molecular events during which the acidic loop exerts its influence. First, the acidic loop promotes the interaction between Cdc34 and its ubiquitin ligase partner, SCF. Second, two glutamic acid residues located on the distal side of the loop collaborate with an invariably conserved histidine on the proximal side of the loop to suppress the pKa of an ionizing species on ubiquitin or Cdc34 which greatly contributes to Cdc34 catalysis. These results demonstrate that insertions can guide E2s to their physiologically relevant ubiquitin ligases as well as provide essential modalities that promote catalysis. 相似文献
622.
Abstract A successful forest tree diversity-monitoring programme delivers reliable estimates of rates of occurrence, the spatial extent and the abundance of all forest-dwelling tree species. Sample-based estimators of these characteristics are provided for North American national forest inventories and discussed in the context of monitoring for forest tree diversity. The expected performance of the Canadian, the United States, and Mexican national forest inventory is quantified for three regions in each country. As expected, estimates for many less common and rare species are imprecise and sometimes these species are missed completely. We suggest augmenting existing national forest inventories by purposive sampling for these species. 相似文献
623.
624.
M. C. Arias Christiane Atteke S. C. Augusto J. Bailey Pilar Bazaga Luciano B. Beheregaray Laure Benoit Rumsaïs Blatrix Céline Born R. M. Brito Hai‐kui Chen Sara Covarrubias Clara de Vega Champlain Djiéto‐Lordon Marie‐Pierre Dubois F. O. Francisco Cristina García P. H. P. Gonçalves Clementina González Carla Gutiérrez‐Rodríguez Michael P. Hammer Carlos M. Herrera H. Itoh S. Kamimura H. Karaoglu S. Kojima Shou‐Li Li Hannah J. Ling Pável F. Matos‐Maraví Doyle McKey Judicaël Mezui‐M'Eko Juan Francisco Ornelas R. F. Park María I. Pozo Satu Ramula Cristina Rigueiro Jonathan Sandoval‐Castillo L. R. Santiago Miyuki M. Seino Chang‐Bing Song H. Takeshima Anti Vasemägi C. R. Wellings Ji Yan Du Yu‐Zhou Chang‐Rong Zhang Tian‐Yun Zhang 《Molecular ecology resources》2013,13(4):760-762
This article documents the addition of 142 microsatellite marker loci to the Molecular Ecology Resources database. Loci were developed for the following species: Agriophyllum squarrosum, Amazilia cyanocephala, Batillaria attramentaria, Fungal strain CTeY1 (Ascomycota), Gadopsis marmoratus, Juniperus phoenicea subsp. turbinata, Liriomyza sativae, Lupinus polyphyllus, Metschnikowia reukaufii, Puccinia striiformis and Xylocopa grisescens. These loci were cross‐tested on the following species: Amazilia beryllina, Amazilia candida, Amazilia rutila, Amazilia tzacatl, Amazilia violiceps, Amazilia yucatanensis, Campylopterus curvipennis, Cynanthus sordidus, Hylocharis leucotis, Juniperus brevifolia, Juniperus cedrus, Juniperus osteosperma, Juniperus oxycedrus, Juniperus thurifera, Liriomyza bryoniae, Liriomyza chinensis, Liriomyza huidobrensis and Liriomyza trifolii. 相似文献
625.
Luana Tatiana Albuquerque Guerreiro Anna Beatriz Robottom-Ferreira Marcelo Ribeiro-Alves Thiago Gomes Toledo-Pinto Tiana Rosa Brito Patrícia Sammarco Rosa Felipe Galvan Sandoval Márcia Rodrigues Jardim Sérgio Gomes Antunes Edward J. Shannon Euzenir Nunes Sarno Maria Cristina Vidal Pessolani Diana Lynn Williams Milton Ozório Moraes 《PloS one》2013,8(6)
Herein, we performed microarray experiments in Schwann cells infected with live M. leprae and identified novel differentially expressed genes (DEG) in M. leprae infected cells. Also, we selected candidate genes associated or implicated with leprosy in genetic studies and biological experiments. Forty-seven genes were selected for validation in two independent types of samples by multiplex qPCR. First, an in vitro model using THP-1 cells was infected with live Mycobacterium leprae and M. bovis bacillus Calmette-Guérin (BCG). In a second situation, mRNA obtained from nerve biopsies from patients with leprosy or other peripheral neuropathies was tested. We detected DEGs that discriminate M. bovis BCG from M. leprae infection. Specific signatures of susceptible responses after M. leprae infection when compared to BCG lead to repression of genes, including CCL2, CCL3, IL8 and SOD2. The same 47-gene set was screened in nerve biopsies, which corroborated the down-regulation of CCL2 and CCL3 in leprosy, but also evidenced the down-regulation of genes involved in mitochondrial metabolism, and the up-regulation of genes involved in lipid metabolism and ubiquitination. Finally, a gene expression signature from DEG was identified in patients confirmed of having leprosy. A classification tree was able to ascertain 80% of the cases as leprosy or non-leprous peripheral neuropathy based on the expression of only LDLR and CCL4. A general immune and mitochondrial hypo-responsive state occurs in response to M. leprae infection. Also, the most important genes and pathways have been highlighted providing new tools for early diagnosis and treatment of leprosy. 相似文献
626.
Sequence analysis of left and right border integration sites of independent, single-copy T-DNA inserts in Arabidopsis thaliana revealed three previously unrecognized concomitants of T-DNA integration. First, genomic pre-insertion sites shared sequence
similarity not only with the T-DNA left and right border regions, as was previously reported, but also at high frequency with
the inverted complement of the T-DNA right border region. Second, palindromic sequences were frequently found to overlap or
lie adjacent to genomic target sites, suggesting a high recombinogenic potential for palindromic elements during T-DNA integration
and a possible role during the primary contact between the T-DNA and the target DNA. Third, “filler” DNA sequences between
genomic pre-insertion site DNA and T-DNA often derive from sequences in the T-DNA left and right border regions that are clustered
around palindromic sequences in these T-DNA regions, suggesting that these palindromic elements are “hot spots” for filler
DNA formation. The discovery of inverted sequence similarities at the right border suggests a previously unrecognized mode
of T-DNA integration that involves heteroduplex formation at both T-DNA borders and with opposite strands of the target DNA.
Scanning for sequence similarities in both direct and inverted orientation may increase the probability and/or effectiveness
of anchoring the T-DNA to the target DNA. Variations on this scheme may also account for inversion events at the target site
of T-DNA integration and inverted T-DNA repeat formation, common sequence organization patterns associated with T-DNA integration.
Electronic Supplementary Material Supplementary material is available in the online version of this article at and is accessible for authorized users. 相似文献
627.
Functionalized microchannels as xylem-mimicking environment: Quantifying X. fastidiosa cell adhesion
Moniellen P. Monteiro Jacobo Hernandez-Montelongo Prasana K. Sahoo Rosaura Hernández Montelongo Douglas S. de Oliveira Maria H.O. Piazzeta Juan P. García Sandoval Alessandra A. de Souza Angelo L. Gobbi Mônica A. Cotta 《Biophysical journal》2021,120(8):1443-1453
Microchannels can be used to simulate xylem vessels and investigate phytopathogen colonization under controlled conditions. In this work, we explore surface functionalization strategies for polydimethylsiloxane and glass microchannels to study microenvironment colonization by Xylella fastidiosa subsp. pauca cells. We closely monitored cell initial adhesion, growth, and motility inside microfluidic channels as a function of chemical environments that mimic those found in xylem vessels. Carboxymethylcellulose (CMC), a synthetic cellulose, and an adhesin that is overexpressed during early stages of X. fastidiosa biofilm formation, XadA1 protein, were immobilized on the device’s internal surfaces. This latter protocol increased bacterial density as compared with CMC. We quantitatively evaluated the different X. fastidiosa attachment affinities to each type of microchannel surface using a mathematical model and experimental observations acquired under constant flow of culture medium. We thus estimate that bacterial cells present ~4 and 82% better adhesion rates in CMC- and XadA1-functionalized channels, respectively. Furthermore, variable flow experiments show that bacterial adhesion forces against shear stresses approximately doubled in value for the XadA1-functionalized microchannel as compared with the polydimethylsiloxane and glass pristine channels. These results show the viability of functionalized microchannels to mimic xylem vessels and corroborate the important role of chemical environments, and particularly XadA1 adhesin, for early stages of X. fastidiosa biofilm formation, as well as adhesivity modulation along the pathogen life cycle. 相似文献
628.
Alejandro Gmez Toledo James T. Sorrentino Daniel R. Sandoval Johan Malmstrm Nathan E. Lewis Jeffrey D. Esko 《The journal of histochemistry and cytochemistry》2021,69(2):105
Heparan sulfate proteoglycans consist of a small family of proteins decorated with one or more covalently attached heparan sulfate glycosaminoglycan chains. These chains have intricate structural patterns based on the position of sulfate groups and uronic acid epimers, which dictate their ability to engage a large repertoire of heparan sulfate–binding proteins, including extracellular matrix proteins, growth factors and morphogens, cytokines and chemokines, apolipoproteins and lipases, adhesion and growth factor receptors, and components of the complement and coagulation system. This review highlights recent progress in the characterization of the so-called “heparan sulfate interactome,” with a major focus on systems-wide strategies as a tool for discovery and characterization of this subproteome. In addition, we compiled all heparan sulfate–binding proteins reported in the literature to date and grouped them into a few major functional classes by applying a networking approach. 相似文献
629.
Nadia Sandoval Laurrabaquio-Alvarado Píndaro Díaz-Jaimes Silvia Hinojosa-Álvarez Maria del Pilar Blanco-Parra Douglas H. Adams Juan Carlos Pérez-Jiménez J. Leonardo Castillo-Géniz 《Journal of fish biology》2021,99(1):275-282
We report for the first time a highly divergent lineage in the Caribbean Sea for the bull shark (Carcharhinus leucas) based on the analysis of 51 mitochondrial DNA genomes of individuals collected in the western North Atlantic. When comparing the mtDNA control region obtained from the mitogenomes to sequences reported previously for Brazil, the Caribbean lineage remained highly divergent. These results support the existence of a discrete population in Central America due to a phylogeographic break separating the Caribbean Sea from the western North Atlantic, Gulf of Mexico and South America. 相似文献
630.
Shiuan Wang Kai Li Tan Melina A. Agosto Bo Xiong Shinya Yamamoto Hector Sandoval Manish Jaiswal Vafa Bayat Ke Zhang Wu-Lin Charng Gabriela David Lita Duraine Kartik Venkatachalam Theodore G. Wensel Hugo J. Bellen 《PLoS biology》2014,12(4)
Rhodopsin mistrafficking can cause photoreceptor (PR) degeneration. Upon light exposure, activated rhodopsin 1 (Rh1) in Drosophila PRs is internalized via endocytosis and degraded in lysosomes. Whether internalized Rh1 can be recycled is unknown. Here, we show that the retromer complex is expressed in PRs where it is required for recycling endocytosed Rh1 upon light stimulation. In the absence of subunits of the retromer, Rh1 is processed in the endolysosomal pathway, leading to a dramatic increase in late endosomes, lysosomes, and light-dependent PR degeneration. Reducing Rh1 endocytosis or Rh1 levels in retromer mutants alleviates PR degeneration. In addition, increasing retromer abundance suppresses degenerative phenotypes of mutations that affect the endolysosomal system. Finally, expressing human Vps26 suppresses PR degeneration in Vps26 mutant PRs. We propose that the retromer plays a conserved role in recycling rhodopsins to maintain PR function and integrity. 相似文献