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971.
Sonja Hartwig Silja Raschke Birgit Knebel Mika Scheler Martin Irmler Waltraud Passlack Stefan Muller Franz-Georg Hanisch Thomas Franz Xinping Li Hans-Dieter Dicken Kristin Eckardt Johannes Beckers Martin Hrabe de Angelis Cora Weigert Hans-Ulrich Häring Hadi Al-Hasani D. Margriet Ouwens Jürgen Eckel Jorg Kotzka Stefan Lehr 《Biochimica et Biophysica Acta - Proteins and Proteomics》2014,1844(5):1011-1017
The skeletal muscle is a metabolically active tissue that secretes various proteins. These so-called myokines have been proposed to affect muscle physiology and to exert systemic effects on other tissues and organs. Yet, changes in the secretory profile may participate in the pathophysiology of metabolic diseases. The present study aimed at characterizing the secretome of differentiated primary human skeletal muscle cells (hSkMC) derived from healthy, adult donors combining three different mass spectrometry based non-targeted approaches as well as one antibody based method. This led to the identification of 548 non-redundant proteins in conditioned media from hSkmc. For 501 proteins, significant mRNA expression could be demonstrated. Applying stringent consecutive filtering using SignalP, SecretomeP and ER_retention signal databases, 305 proteins were assigned as potential myokines of which 12 proteins containing a secretory signal peptide were not previously described. This comprehensive profiling study of the human skeletal muscle secretome expands our knowledge of the composition of the human myokinome and may contribute to our understanding of the role of myokines in multiple biological processes. This article is part of a Special Issue entitled: Biomarkers: A Proteomic Challenge. 相似文献
972.
Facilitative plant interactions and climate simultaneously drive alpine plant diversity 总被引:1,自引:0,他引:1
Lohengrin A. Cavieres Rob W. Brooker Bradley J. Butterfield Bradley J. Cook Zaal Kikvidze Christopher J. Lortie Richard Michalet Francisco I. Pugnaire Christian Schöb Sa Xiao Fabien Anthelme Robert G. Björk Katharine J. M. Dickinson Brittany H. Cranston Rosario Gavilán Alba Gutiérrez‐Girón Robert Kanka Jean‐Paul Maalouf Alan F. Mark Jalil Noroozi Rabindra Parajuli Gareth K. Phoenix Anya M. Reid Wendy M. Ridenour Christian Rixen Sonja Wipf Liang Zhao Adrián Escudero Benjamin F. Zaitchik Emanuele Lingua Erik T. Aschehoug Ragan M. Callaway 《Ecology letters》2014,17(2):193-202
Interactions among species determine local‐scale diversity, but local interactions are thought to have minor effects at larger scales. However, quantitative comparisons of the importance of biotic interactions relative to other drivers are rarely made at larger scales. Using a data set spanning 78 sites and five continents, we assessed the relative importance of biotic interactions and climate in determining plant diversity in alpine ecosystems dominated by nurse‐plant cushion species. Climate variables related with water balance showed the highest correlation with richness at the global scale. Strikingly, although the effect of cushion species on diversity was lower than that of climate, its contribution was still substantial. In particular, cushion species enhanced species richness more in systems with inherently impoverished local diversity. Nurse species appear to act as a ‘safety net’ sustaining diversity under harsh conditions, demonstrating that climate and species interactions should be integrated when predicting future biodiversity effects of climate change. 相似文献
973.
974.
975.
976.
Larissa Pusch Sonja Wegmann Jack D. Caldwell Gustav F. Jirikowski 《Cellular and molecular neurobiology》2009,29(4):583-588
Glial tumor cells are known to be sensitive to glucocorticoids (GC) in vivo and in vitro. Here we studied the expression of
corticosteroid-binding globulin (CBG) in the low-grade malignant human astrocytoma cell line 1321N1. CBG was observed in cytoplasm
of most of these cells with immunocytochemistry. RT-PCR revealed the presence of the respective mRNA. Only scattered cells
contained nuclear immunoreactivity for glucocorticoid receptor as visualized by double immunostaining. Immunoreactive CBG
could be recovered from the supernatant of cultures that had been exposed to 10−5 M cortisol. Our observations indicate the endogenous expression of CBG in 1321N1 cells which may occur independently from
classical glucocorticoid receptor pathways. Cortisol seems to facilitate liberation of CBG in a paracrine manner, perhaps
through membrane action of the steroid. Effects of adrenal steroids on proliferation and apoptosis of certain glial tumors
may in part depend on these mechanisms. 相似文献
977.
Sonja Gaber Eva Elisa Fischerauer Eleonore Fröhlich Gregor Janezic Florian Amerstorfer Annelie-Martina Weinberg 《Cell and tissue research》2009,335(3):539-549
Post-traumatic overgrowth of growing long bones is a common clinical phenomenon in paediatric traumatology and is the result
of an enhanced stimulation of the nearby growth plate after fracture. To date, the exact post-fractural reactions of the growth
plate are poorly understood. The aim of this study has been to determine the impact of fracture on the frequency of chondrocyte
apoptosis of the growth plate. Rats sustained a mid-diaphyseal closed fracture of the left tibia or were left untreated. All
animals were killed 3, 10, 14 or 29 days after trauma. The left and right tibiae were harvested and apoptotic chondrocytes
of the proximal tibial growth plate were detected by TUNEL staining. The apoptosis percentage of physeal chondrocytes was
statistically compared among fractured bones, intact contra-lateral bones and control bones. The physeal apoptosis rate of
the fractured bone was significantly higher than that of the contra-lateral intact bone (valid for all evaluated days) and
the control bone (valid from day 10 onwards). Contra-lateral intact tibiae never showed significantly higher apoptosis rates
compared with control tibiae. Thus, mid-diaphyseal fracture influences the nearby growth plate by stimulating chondrocyte
programmed cell death, which is associated with cartilage resorption and bone replacement. The lack of a significant difference
between the intact contra-lateral and the intact control bone suggests that fracture only has a local effect that contributes
to the greater apoptosis rate of the adjacent physis. 相似文献
978.
Klaus-Peter Michel Ann-Kristin Schröder Maike Zimmermann Sonja Brandt Elfriede K. Pistorius Nicole Frankenberg-Dinkel Dorothee Staiger 《Archives of microbiology》2009,191(6):553-559
The cyanobacterium Synechocystis sp. PCC 6803 harbours 47 histidine kinases (Hiks). Among these are hybrid histidine kinases with one or two response regulator
domains as well as numerous Hiks with several sensory domains. One example is the hybrid histidine kinase Slr1759 (Hik14)
that has two PAS domains arranged in tandem linked to a predicted GAF domain. Here, we show that a Slr1759 derivative recombinantly
expressed in Escherichia coli has a flavin cofactor. Using truncated Slr1759 variants, it is shown that the flavin associates with the first PAS domain.
The cofactor reconstitutes the activity of d-amino acid oxidase apoprotein from pig kidney, indicating that the flavin derivative is FAD. Furthermore, the Slr1759 histidine
kinase domain indeed undergoes autophosphorylation in vitro. The phosphorylated product of a recombinant Slr1759 derivative
is sensitive to acids, pointing to a histidine residue as the phosphate-accepting group. 相似文献
979.
Kukavica Biljana; Mojovic Milos; Vuccinic Zeljko; Maksimovic Vuk; Takahama Umeo; Jovanovic Sonja Veljovic 《Plant & cell physiology》2009,50(2):304-317
The hydroxyl radical produced in the apoplast has been demonstratedto facilitate cell wall loosening during cell elongation. Cellwall-bound peroxidases (PODs) have been implicated in hydroxylradical formation. For this mechanism, the apoplast or cellwalls should contain the electron donors for (i) H2O2 formationfrom dioxygen; and (ii) the POD-catalyzed reduction of H2O2to the hydroxyl radical. The aim of the work was to identifythe electron donors in these reactions. In this report, hydroxylradical (·OH) generation in the cell wall isolated frompea roots was detected in the absence of any exogenous reductants,suggesting that the plant cell wall possesses the capacity togenerate ·OH in situ. Distinct POD and Mn-superoxidedismutase (Mn-SOD) isoforms different from other cellular isoformswere shown by native gel electropho-resis to be preferably boundto the cell walls. Electron paramagnetic resonance (EPR) spectroscopyof cell wall isolates containing the spin-trapping reagent,5-diethoxyphosphoryl-5-methyl-1-pyrroline-N-oxide (DEPMPO),was used for detection of and differentiation between ·OHand the superoxide radical (O2–·). The data obtainedusing POD inhibitors confirmed that tightly bound cell wallPODs are involved in DEPMPO/OH adduct formation. A decreasein DEPMPO/OH adduct formation in the presence of H2O2 scavengersdemonstrated that this hydroxyl radical was derived from H2O2.During the generation of ·OH, the concentration of quinhydronestructures (as detected by EPR spectroscopy) increased, suggestingthat the H2O2 required for the formation of ·OH in isolatedcell walls is produced during the reduction of O2 by hydroxycinnamicacids. Cell wall isolates in which the proteins have been denaturated(including the endogenous POD and SOD) did not produce ·OH.Addition of exogenous H2O2 again induced the production of ·OH,and these were shown to originate from the Fenton reaction withtightly bound metal ions. However, the appearance of the DEPMPO/OOHadduct could also be observed, due to the production of O2–·when endogenous SOD has been inactivated. Also, O2–·was converted to ·OH in an in vitro horseradish peroxidase(HRP)/H2O2 system to which exogenous SOD has been added. Takentogether with the discovery of the cell wall-bound Mn-SOD isoform,these results support the role of such a cell wall-bound SODin the formation of ·OH jointly with the cell wall-boundPOD. According to the above findings, it seems that the hydroxycinnamicacids from the cell wall, acting as reductants, contribute tothe formation of H2O2 in the presence of O2 in an autocatalyticmanner, and that POD and Mn-SOD coupled together generate ·OHfrom such H2O2. 相似文献
980.
Frank P.L. Lai Malgorzata Szczodrak J. Margit Oelkers Markus Ladwein Filippo Acconcia Stefanie Benesch Sonja Auinger Jan Faix J. Victor Small Simona Polo Theresia E.B. Stradal Klemens Rottner 《Molecular biology of the cell》2009,20(14):3209-3223
Dynamic actin rearrangements are initiated and maintained by actin filament nucleators, including the Arp2/3-complex. This protein assembly is activated in vitro by distinct nucleation-promoting factors such as Wiskott-Aldrich syndrome protein/Scar family proteins or cortactin, but the relative in vivo functions of each of them remain controversial. Here, we report the conditional genetic disruption of murine cortactin, implicated previously in dynamic actin reorganizations driving lamellipodium protrusion and endocytosis. Unexpectedly, cortactin-deficient cells showed little changes in overall cell morphology and growth. Ultrastructural analyses and live-cell imaging studies revealed unimpaired lamellipodial architecture, Rac-induced protrusion, and actin network turnover, although actin assembly rates in the lamellipodium were modestly increased. In contrast, platelet-derived growth factor-induced actin reorganization and Rac activation were impaired in cortactin null cells. In addition, cortactin deficiency caused reduction of Cdc42 activity and defects in random and directed cell migration. Reduced migration of cortactin null cells could be restored, at least in part, by active Rac and Cdc42 variants. Finally, cortactin removal did not affect the efficiency of receptor-mediated endocytosis. Together, we conclude that cortactin is fully dispensable for Arp2/3-complex activation during lamellipodia protrusion or clathrin pit endocytosis. Furthermore, we propose that cortactin promotes cell migration indirectly, through contributing to activation of selected Rho-GTPases. 相似文献