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141.
Lopez-Herrera G Tampella G Pan-Hammarström Q Herholz P Trujillo-Vargas CM Phadwal K Simon AK Moutschen M Etzioni A Mory A Srugo I Melamed D Hultenby K Liu C Baronio M Vitali M Philippet P Dideberg V Aghamohammadi A Rezaei N Enright V Du L Salzer U Eibel H Pfeifer D Veelken H Stauss H Lougaris V Plebani A Gertz EM Schäffer AA Hammarström L Grimbacher B 《American journal of human genetics》2012,90(6):986-1001
Most autosomal genetic causes of childhood-onset hypogammaglobulinemia are currently not well understood. Most affected individuals are simplex cases, but both autosomal-dominant and autosomal-recessive inheritance have been described. We performed genetic linkage analysis in consanguineous families affected by hypogammaglobulinemia. Four consanguineous families with childhood-onset humoral immune deficiency and features of autoimmunity shared genotype evidence for a linkage interval on chromosome 4q. Sequencing of positional candidate genes revealed that in each family, affected individuals had a distinct homozygous mutation in LRBA (lipopolysaccharide responsive beige-like anchor protein). All LRBA mutations segregated with the disease because homozygous individuals showed hypogammaglobulinemia and autoimmunity, whereas heterozygous individuals were healthy. These mutations were absent in healthy controls. Individuals with homozygous LRBA mutations had no LRBA, had disturbed B cell development, defective in vitro B cell activation, plasmablast formation, and immunoglobulin secretion, and had low proliferative responses. We conclude that mutations in LRBA cause an immune deficiency characterized by defects in B cell activation and autophagy and by susceptibility to apoptosis, all of which are associated with a clinical phenotype of hypogammaglobulinemia and autoimmunity. 相似文献
142.
G Scornavacca R Gesuete F Orsini R Pastorelli R Fanelli MG de Simoni L Airoldi 《Journal of neurochemistry》2012,122(6):1219-1229
J. Neurochem. (2012) 122, 1219-1229. ABSTRACT: The molecular mechanisms that lead to ischemic pre-conditioning are not completely understood, and proteins are important players. We compared the mouse brain cortex proteome from different ischemia sets: transient (7?min) middle cerebral artery occlusion (7'MCAo, pre-conditioning stimulus), permanent MCAo (pMCAo, severe ischemia), and pMCAo 4?days after 7'MCAo (7'MCAo/pMCAo, pre-conditioned model). Proteins were analyzed by two-dimensional electrophoresis coupled to liquid chromatography-tandem mass spectrometry. Overall, 28 proteins were expressed differentially from sham controls, and identified. The ischemic pre-conditioning stimulus alone up-regulated the stress protein heat-shock protein 70 (HSP70), possibly activated by the androgen receptor. Western blotting confirmed the increased expression of HSP70 and showed that androgen receptor expression paralleled that of HSP70. In the ischemic-tolerant group (7'MCAo/pMCAo), a number of proteins over-expressed after pMCAo returned to sham levels, seven proteins remained up-regulated as in pMCAo, and five proteins mainly involved in energy metabolism and mitochondrial electron transport and unchanged in pMCAo were down-regulated only in ischemic tolerance, suggesting a role in brain pre-conditioning. Astrocytes participated in ischemic-tolerance induction, as shown by the down-regulation of glutamine synthetase in the 7'MCAo/pMCAo group. The results suggest that metabolic down-regulation was a general feature of ischemic pre-conditioning, playing a pivotal role in neuroprotection. 相似文献
143.
Dinoflagellate algae of the genus Symbiodinium occur as endosymbionts in a variety of hosts including coral. The response of Symbiodinium spp. to environmental changes could dictate survival of their hosts and the ecological success of coral reef ecosystems. Oxidative stress has been linked to a breakdown in this symbiotic relationship, known as bleaching. Increased temperature is one of the primary environmental changes linked to this phenomenon. Preliminary studies have established high concentrations of the sulfur compound dimethylsulfoniopropionate (DMSP) in Symbiodinium spp., with increased temperature. To examine the potential use of DMSP as an antioxidant, a 5?day incubation experiment was conducted at two temperatures with the algae S. microadriaticum (CCMP1633) isolated from the cnidarian host Aiptasia pulchella. An HPLC assay for the activity of the enzyme B12-dependent methionine synthase was modified and used to determine the link between de novo production of methionine, a precursor to DMSP, and temperature induced oxidative stress. DMSP concentrations per cell increased approximately 38?% in the 33?°C treatment cultures over 120?h. However, these cells also increased more than 2-fold in biovolume (127?±?43?%), and SYTO-BC stain indicated increased DNA content (approximately 4-fold), suggesting arrested cell division. Normalization of DMSP to biovolume revealed that the concentrations actually decreased approximately 49?% after 2?days in cultures exposed to elevated temperature (33?°C), but were not significantly different from the control treatment at 120?h (27?°C). Concomitant changes in the 33?°C treatment relative to the control (after 120?h) resulted in an approximately 8-fold increase in reactive oxygen species, a 37?% (±7?%) decrease in photosynthetic efficiency of photosystem II, and a 5-fold increase in xanthophyll cycling. Methionine synthase activity (MSA) correlated to the decrease in DMSP concentration (R 2?=?0.778), with decreasing activity at the high temperature. Given this decrease in MSA, the increase in DMSP per cell may be due to DMSP production utilizing methionine from protein turnover, and not de novo synthesis via MSA. The findings of this study provide insight into the responses of algal symbionts to environmental changes, shed light on the potential use of DMSP and other known photo-protective mechanisms such as xanthophyll cycling under temperature induced oxidative stress, and support the suspected cessation of cell division under these conditions. This information could be crucial to understanding cellular responses to environmental changes and the ability of these organisms to survive under elevated sea surface temperatures projected for the near future. 相似文献
144.
Sexton T Yaffe E Kenigsberg E Bantignies F Leblanc B Hoichman M Parrinello H Tanay A Cavalli G 《Cell》2012,148(3):458-472
Chromosomes are the physical realization of genetic information and thus form the basis for its readout and propagation. Here we present a high-resolution chromosomal contact map derived from a modified genome-wide chromosome conformation capture approach applied to Drosophila embryonic nuclei. The data show that the entire genome is linearly partitioned into well-demarcated physical domains that overlap extensively with active and repressive epigenetic marks. Chromosomal contacts are hierarchically organized between domains. Global modeling of contact density and clustering of domains show that inactive domains are condensed and confined to their chromosomal territories, whereas active domains reach out of the territory to form remote intra- and interchromosomal contacts. Moreover, we systematically identify specific long-range intrachromosomal contacts between Polycomb-repressed domains. Together, these observations allow for quantitative prediction of the Drosophila chromosomal contact map, laying the foundation for detailed studies of chromosome structure and function in a genetically tractable system. 相似文献
145.
Florio M Leto K Muzio L Tinterri A Badaloni A Croci L Zordan P Barili V Albieri I Guillemot F Rossi F Consalez GG 《Development (Cambridge, England)》2012,139(13):2308-2320
By serving as the sole output of the cerebellar cortex, integrating a myriad of afferent stimuli, Purkinje cells (PCs) constitute the principal neuron in cerebellar circuits. Several neurodegenerative cerebellar ataxias feature a selective cell-autonomous loss of PCs, warranting the development of regenerative strategies. To date, very little is known as to the regulatory cascades controlling PC development. During central nervous system development, the proneural gene neurogenin 2 (Neurog2) contributes to many distinct neuronal types by specifying their fate and/or dictating development of their morphological features. By analyzing a mouse knock-in line expressing Cre recombinase under the control of Neurog2 cis-acting sequences we show that, in the cerebellar primordium, Neurog2 is expressed by cycling progenitors cell-autonomously fated to become PCs, even when transplanted heterochronically. During cerebellar development, Neurog2 is expressed in G1 phase by progenitors poised to exit the cell cycle. We demonstrate that, in the absence of Neurog2, both cell-cycle progression and neuronal output are significantly affected, leading to an overall reduction of the mature cerebellar volume. Although PC fate identity is correctly specified, the maturation of their dendritic arbor is severely affected in the absence of Neurog2, as null PCs develop stunted and poorly branched dendrites, a defect evident from the early stages of dendritogenesis. Thus, Neurog2 represents a key regulator of PC development and maturation. 相似文献
146.
147.
Pichia fermentans DiSAABA 726 is a biofilm-forming yeast that undergoes dimorphic transition. Under yeast-like morphology it controls brown rot caused by Monilia spp. on apple fruit, while under pseudohyphal form, it shows pathogenic behaviour itself on peach fruit. The present study investigates the nutritional factors that induce and separate yeast-like and pseudohyphal morphologies under laboratory conditions. We show that P. fermentans DiSAABA 726 produces mainly yeast-like cells on media containing millimolar concentrations of urea and diammonium phosphate, and forms pseudohyphae at micromolar concentrations of these two salts. With ammonium sulphate, yeast-like or pseudohyphal morphology depends on the N concentration and the pH of the culture media. Amino acids such as methionine, valine, and phenylalanine invariably induce pseudohyphal morphology irrespective of the N concentration and the pH of the culture media. Methionol, 1-butanol, isobutanol, and isopropanol induce pseudohyphal growth, while phenylethanol and isoamyl alcohol fail to induce the formation of filaments. Thus, the morphogenesis of P. fermentans DiSAABA 726 depends more on the nitrogen source than on the N concentration, and is regulated by the quorum-sensing molecules that are generally produced from amino-acid assimilation under nitrogen starvation. 相似文献
148.
Vaschetto R Kroumova V Olivieri C Bergamaschi V Cancelliere L Borrè S Fortina G Navalesi P Della Corte F 《The new microbiologica》2012,35(1):77-82
A 22-year-old insulin-dependent diabetic male was admitted for diabetic ketoacidosis. He developed hospital-acquired pneumonia (HAP) for which empirical antibiotic and antifungal therapy was started on the ward. On day 6, clinical and laboratory findings worsened, and bronchoalveolar lavage (BAL) was performed. Serum real time-polymerase chain reaction (RT-PCR) indicated invasive pulmonary aspergillosis (IPA) and led to antifungal therapy being initiated 48 hours before the results of the BAL culture were available. Despite early appropriate antifungal therapy, however, the patient died on day 22 while being supported by venovenous extracorporeal membrane oxygenation. 相似文献
149.
G Sachs J Traugott AP Nesterova G Dell'omo F Kümmeth W Heidrich AL Vyssotski F Bonadonna 《PloS one》2012,7(9):e41449
ALBATROSSES DO SOMETHING THAT NO OTHER BIRDS ARE ABLE TO DO: fly thousands of kilometres at no mechanical cost. This is possible because they use dynamic soaring, a flight mode that enables them to gain the energy required for flying from wind. Until now, the physical mechanisms of the energy gain in terms of the energy transfer from the wind to the bird were mostly unknown. Here we show that the energy gain is achieved by a dynamic flight manoeuvre consisting of a continually repeated up-down curve with optimal adjustment to the wind. We determined the energy obtained from the wind by analysing the measured trajectories of free flying birds using a new GPS-signal tracking method yielding a high precision. Our results reveal an evolutionary adaptation to an extreme environment, and may support recent biologically inspired research on robotic aircraft that might utilize albatrosses' flight technique for engineless propulsion. 相似文献
150.
Gianfranco De Feo Giacomo Chiabrando Nunzia Cannovo Antonio Galluccio Carlo Tomino 《PloS one》2012,7(11)