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941.
Revisiting Kadenbach: Electron flux rate through cytochrome c‐oxidase determines the ATP‐inhibitory effect and subsequent production of ROS 下载免费PDF全文
Sebastian Vogt Annika Rhiel Petra Weber Rabia Ramzan 《BioEssays : news and reviews in molecular, cellular and developmental biology》2016,38(6):556-567
Mitochondrial respiration is the predominant source of ATP. Excessive rates of electron transport cause a higher production of harmful reactive oxygen species (ROS). There are two regulatory mechanisms known. The first, according to Mitchel, is dependent on the mitochondrial membrane potential that drives ATP synthase for ATP production, and the second, the Kadenbach mechanism, is focussed on the binding of ATP to Cytochrome c Oxidase (CytOx) at high ATP/ADP ratios, which results in an allosteric conformational change to CytOx, causing inhibition. In times of stress, ATP‐dependent inhibition is switched off and the activity of CytOx is exclusively determined by the membrane potential, leading to an increase in ROS production. The second mechanism for respiratory control depends on the quantity of electron transfer to the Heme aa3 of CytOx. When ATP is bound to CytOx the enzyme is inhibited, and ROS formation is decreased, although the mitochondrial membrane potential is increased. 相似文献
942.
Anne Kosfeld Martin Kreuzer Christoph Daniel Frank Brand Anne-Kathrin Schäfer Alexandra Chadt Anna-Carina Weiss Vera Riehmer Cécile Jeanpierre Michael Klintschar Jan Hinrich Bräsen Kerstin Amann Lars Pape Andreas Kispert Hadi Al-Hasani Dieter Haffner Ruthild G. Weber 《Human genetics》2016,135(1):69-87
943.
Summary The haustorial structure of three African parasitic members of the family Scrophulariaceae (Buchnera hispida, Rhamphicarpa fistulosa, andStriga hermonthica) has been studied with regard to the interface between haustoria and the invaded host roots. Immunocytochemical observations at the light and electron microscopical level were carried out with monoclonal antibodies against pectin. JIM5, JIM7, and hydroxyproline-rich glycoprotein (HRGP), LM1. Lignins have been visualized by phloroglucinolhydrochloric acid staining. At the margin of the lateral interface (contact area of host root cortex and parasite cells), JIM5- and JIM7-labelled substances accumulate between parasite papillae and the host root surface indicating that pectins are implicated in sealing the parasite to the attacked host organ. The lateral interface is characterized by the presence of compressed, necrotic host cells, whereas the central interface (contact area between host stele and parasite cells) is generally devoid of host cell remnants. Phenolic substances and/or lignins can be found at the site of penetration of the haustorium into the host root. These observations and the fact that HRGPs accumulate at the host side of the interface support the view of, at least, a partial defense reaction in the invaded host root tissues. Within haustoria, HRGPs were restricted to differentiating xylem elements, implying a spatio-temporal regulation of HRGPs in developmental processes.Abbreviations BSA
bovine serum albumin
- FITC
fluorescein isothiocyanate
- HRGP
hydroxyproline-rich glycoprotein
- LM
light microscopy
- MAb
monoclonal antibody
- TBSB
Tris-buffered saline with bovine serum albumin
- TBSB-T
Tris-buffered saline with bovine serum albumin and Tween 20
- TEM
transmission electron microscopy 相似文献
944.
T L Shih M R Candelore M A Cascieri S H Chiu L F Colwell L Deng W P Feeney M J Forrest G J Hom D E MacIntyre R R Miller R A Stearns C D Strader L Tota M J Wyvratt M H Fisher A E Weber 《Bioorganic & medicinal chemistry letters》1999,9(9):1251-1254
L-770,644 (9c) is a potent and selective agonist of the human beta3 adrenergic receptor (EC50 = 13 nM). It shows good oral bioavailability in both dogs and rats (%F = 27), and is a full agonist for glycerolemia in the rhesus monkey (ED50 = 0.21 mg/kg). Based on its desirable in vitro and in vivo properties, L-770,644 was chosen for further preclinical evaluation. 相似文献
945.
Upal Ghosh A. Scott Weber James N. Jensen John R. Smith 《Soil & Sediment Contamination》1999,8(5):593-613
The purpose of this research was to study congener level PCB desorption kinetics of field-contaminated sediments and develop a simple methodology to analyze the desorption behavior. Batch desorption kinetic studies were conducted using XAD-4 resin. Two-phase desorption kinetics were observed for most PCB congeners, consisting of an initial fast rate followed by an extended period of slow rate. A dual first-order rate model was fitted to the PCB desorption data to estimate PCB concentrations in the fast and slow desorbing pools. The fast and slow desorption rates were found to decrease with increasing chlorina-tion of PCB congeners, decreasing ortho chlorination, and decreasing temperature. Estimated first-order desorption rate constants for the fast pools were found to be two orders of magnitude higher than those for the corresponding slow pools. The log of first-order rate constants for the different PCB congeners were found to be linearly related to the log of octanol-water partition coefficients. Therefore, desorption rate constants of higher chlorinated PCB congeners, which typically require long-term desorption tests, could be extrapolated using measured rate constants of lower-chlorinated PCB congeners from short-term desorption tests. This finding may provide a process to significantly reduce the duration of experiments required for estimating desorption kinetics. 相似文献
946.
Peter Stlberg Shu Wang Catharina Larsson Günther Weber Kjell
berg Anders Gobl Britt Skogseid 《FEBS letters》1999,450(3):703
The expression of phospholipase C β 3 (PLCB3) is low or absent in several neuroendocrine neoplasias. To investigate the role of PLCB3 in the neuroendocrine tumorigenesis, we transfected a PLCB3 construct to three neuroendocrine tumor cell lines with a low PLCB3 expression. The growth rate and tumorigenicity were assessed in vitro by [3H]thymidine incorporation and cell counting, in vivo, by xenografting to nude mice. In vitro, PLCB3 expressing clones showed a significant growth inhibition. The tumor weight was reduced for one of the two xenografted PLCB3-transfected cell lines and in both, a reduced number of proliferating (Ki-67 positive) cells was observed. This study implies an essential role for PLCB3 in the neuroendocrine tumorigenesis. 相似文献
947.
An analysis of polygenes affecting wing shape on chromosome 3 in Drosophila melanogaster. 总被引:1,自引:0,他引:1
Loci on the third chromosome of Drosophila melanogaster that affect an index of wing shape were mapped, using recombinant isogenic lines, with transposable elements as markers. Many genes with small subequal effects are dispersed along the whole chromosome. Their alleles act nearly additively in heterozygotes. They have small correlated effects on leg shape, but no detectable effects on halteres. Small negative net interactions occur over most of the chromosome. The data set of 519 recombinant isogenic lines can be explained reasonably well by two models. One model posits an indefinitely large number of loci with no interactions. The other model posits 11 loci with additive effects whose sum equals the total phenotypic range and with large positive and negative interactions that nearly cancel each other. 相似文献
948.
Keqing Huang Lichun Chang Yihui Hou Wenzhong Ji Thành Trần-Phú Anh Dinh Bui Azul Osorio Mayon Wei Wang Olivier Lee Cheong Lem Dang-Thuan Nguyen Grace Dansoa Tabi Leiping Duan Yun Liu Heping Shen Junliang Yang Thomas P. White Kylie R. Catchpole Klaus J. Weber The Duong 《Liver Transplantation》2024,14(17):2304073
Due to the limited interface contact and weak interfacial interaction, planar heterojunction perovskite solar cells (PSCs) have space for further improvement. Herein, a structural and chemical crosslinking interface is proposed and constructed by introducing an extra layer, which blends tin dioxide (SnO2) nanoparticles with chloride salts. Since the incorporated materials can be dissolved during the fabrication of perovskite, the quality of perovskite films is improved, leading to larger grain size and reduced trap-state density. Also, more chloride ions at the SnO2/perovskite interface are observed and the interaction between Cl− and Sn4+ is confirmed. It results in more pronounced n-type SnO2 with better conductivity and deeper conduction bands, leading to preferable energy level alignment between SnO2 and perovskite. Consequently, the open-circuit voltage and fill factor of the devices increase, and target cells present better stability, retaining 98% of initial efficiencies after >10 000 h storage in dry air (≈5% relative humidity) and maintaining 85.50% of the initial efficiency after 1000 h of operation under light. This strategy enables the achievement of 25.28% efficiency with a low bandgap (1.53 eV) perovskite composition, and it is confirmed to be universal when other related materials are utilized. 相似文献
949.
Alexander J. Weitzel Hannah A. Grunwald Ceri Weber Rimma Levina Valentino M. Gantz Stephen M. Hedrick Ethan Bier Kimberly L. Cooper 《PLoS biology》2021,19(12)
Highly efficient gene conversion systems have the potential to facilitate the study of complex genetic traits using laboratory mice and, if implemented as a “gene drive,” to limit loss of biodiversity and disease transmission caused by wild rodent populations. We previously showed that such a system of gene conversion from heterozygous to homozygous after a sequence targeted CRISPR/Cas9 double-strand DNA break (DSB) is feasible in the female mouse germline. In the male germline, however, all DSBs were instead repaired by end joining (EJ) mechanisms to form an “insertion/deletion” (indel) mutation. These observations suggested that timing Cas9 expression to coincide with meiosis I is critical to favor conditions when homologous chromosomes are aligned and interchromosomal homology-directed repair (HDR) mechanisms predominate. Here, using a Cas9 knock-in allele at the Spo11 locus, we show that meiotic expression of Cas9 does indeed mediate gene conversion in the male as well as in the female germline. However, the low frequency of both HDR and indel mutation in both male and female germlines suggests that Cas9 may be expressed from the Spo11 locus at levels too low for efficient DSB formation. We suggest that more robust Cas9 expression initiated during early meiosis I may improve the efficiency of gene conversion and further increase the rate of “super-mendelian” inheritance from both male and female mice.This study shows that while Cas9 expression during meiosis I promotes genotype conversion - the mechanism underlying CRISPR ’gene drive’ - in both male and female mice, timing and high levels of Cas9 protein are critical to achieve robust efficiency. 相似文献
950.