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991.
Intracellular sorting of alcohol dehydrogenase isoenzymes in yeast: a cytosolic location reflects absence of an amino-terminal targeting sequence for the mitochondrion. 总被引:10,自引:2,他引:10 下载免费PDF全文
The yeast Saccharomyces cerevisiae contains three alcohol dehydrogenase isoenzymes (ADHI-ADHIII), two in the cytoplasm (ADHI and ADHII) and one in the mitochondrion (ADHIII). Sequence comparison of the corresponding nuclear genes showed that these three proteins are 80-90% identical except for a 27-amino acid extension at the amino terminus of ADHIII. Here we demonstrate that ADHIII is located inside the mitochondrial inner membrane. We also show, using gene fusions, that the amino terminus of ADHIII contains the information for targeting the protein to and transporting it into the mitochondrion. The mitochondrial isoenzyme ADHIII can be converted into a cytosolic protein by deleting its first 28 amino acids. Conversely, the cytoplasmic isoenzyme ADHII can be converted into a mitochondrial isoenzyme by replacing its first 21 amino acids with the first 48 amino acids of ADHIII. We conclude that ADHII is a cytosolic protein because it lacks an amino-terminal targeting sequence for the mitochondrion and that ADHIII is a mitochondrial protein because it contains a mitochondrial targeting sequence. 相似文献
992.
Young A. J.; Muza S. R.; Sawka M. N.; Gonzalez R. R.; Pandolf K. B. 《Journal of applied physiology》1986,60(5):1542-1548
The effects of repeated cold water immersion on thermoregulatory responses to cold air were studied in seven males. A cold air stress test (CAST) was performed before and after completion of an acclimation program consisting of daily 90-min cold (18 degrees C) water immersion, repeated 5 times/wk for 5 consecutive wk. The CAST consisted of resting 30 min in a comfortable [24 degrees C, 30% relative humidity (rh)] environment followed by 90 min in cold (5 degrees C, 30% rh) air. Pre- and postacclimation, metabolism (M) increased (P less than 0.01) by 85% during the first 10 min of CAST and thereafter rose slowly. After acclimation, M was lower (P less than 0.02) at 10 min of CAST compared with before, but by 30 min M was the same. Therefore, shivering onset may have been delayed following acclimation. After acclimation, rectal temperature (Tre) was lower (P less than 0.01) before and during CAST, and the drop in Tre during CAST was greater (P less than 0.01) than before. Mean weighted skin temperature (Tsk) was lower (P less than 0.01) following acclimation than before, and acclimation resulted in a larger (P less than 0.02) Tre-to-Tsk gradient. Plasma norepinephrine increased during both CAST (P less than 0.002), but the increase was larger (P less than 0.004) following acclimation. These findings suggest that repeated cold water immersion stimulates development of true cold acclimation in humans as opposed to habituation. The cold acclimation produced appears to be of the insulative type. 相似文献
993.
Tissue expression and cellular localization of phospholipid hydroperoxide glutathione peroxidase (PHGPx) mRNA in male mice 总被引:1,自引:0,他引:1
Baek IJ Seo DS Yon JM Lee SR Jin Y Nahm SS Jeong JH Choo YK Kang JK Lee BJ Yun YW Nam SY 《Journal of molecular histology》2007,38(3):237-244
Phospholipid hydroperoxide glutathione peroxidase (PHGPx) is an ubiquitous antioxidant enzyme, but the exact expression pattern
in mammalian tissues is still unknown. The expression and cellular localization of PHGPx mRNA were examined in male mice using
real time-polymerase chain reaction and in situ hybridization techniques. The rank order of PHGPx mRNA expression across tissues exhibiting substantial levels of expression
was:testes ≫ heart > cerebrum ≥ ileum > stomach = liver = jejunum ≥ epididymis. In testes, PHGPx mRNA was highly expressed
in spermiogenic cells and Leydig cells. The signal was also expressed in the molecular layer, Purkinje cell layer, and white
matter of cerebellum, the pituicytes of neurohypophysis, the parafollicular cells and follicular basement membrane of thyroid,
the exocrine portion of pancreas, the tubular epithelium of kidney, the smooth muscle cells of arteries, and the red pulp
of spleen. In the gastrointestinal tract, PHGPx mRNA expression was mainly observed in the keratinized surface epithelium
of forestomach, the submucosal glands and serosa layers, and further the Paneth cells of intestines. PHGPx mRNA appeared to
be ubiquitously expressed in the parenchyma of heart, liver, and lung. These results indicate that PHGPx exhibits a cell-
and tissue-specific expression pattern in mice. 相似文献
994.
Kim DW Lee JH Park SK Yang WM Jeon GS Lee YH Chung CK Cho SS 《Neurochemical research》2007,32(9):1460-1468
Glycogen synthase kinase 3β (GSK3β) is believed to play important roles in the regulation of synaptic plasticity, cell survival
and circadian rhythms in the mature CNS. However, although several studies have been focused on the GSK3β, little is known
about GSK3β changes in glial cells under neuropathological conditions. In this study, we evaluated the expressions of molecules
associated with the GSK3β signaling pathway, following the induction of an excitotoxic lesion in mouse brain by kainic acid
(KA) injection, which caused pyramidal cell degeneration in the hippocampal CA3 region. In injured hippocampi, Ser47-Akt (protein
kinase B, PKB) phosphorylation increased from 4 h until 1 day post-injection (PI). Ser9-GSK3β and Ser133-cAMP responsive element-binding
protein (CREB) phosphorylations showed similar spatiotemporal patterns in hippocampi at 1 day until 3 days PI. Double immunohistochemistry
also showed that these phosphorylated forms of Akt, GSK3β and CREB were expressed in astrocytes. For the first time, our data
demonstrate the injury-induced astrocytic changes in the levels of phosphorylation of Akt, -GSK3β and -CREB in vivo, which
may reflect mechanisms of glial cells protection or adaptive response to damage.
DW Kim and JH Lee contributed equally to this work. 相似文献
995.
Lee DG Jeon JH Jang MK Kim NY Lee JH Lee JH Kim SJ Kim GD Lee SH 《Biotechnology letters》2007,29(3):465-472
A metagenomic library was constructed using total genomic DNA extracted from the mud in the west coast of Korea and was used
together with a fosmid vector, pCC1FOS in order to uncover novel gene sources. One clone from approximately 30,000 recombinant
Escherichia coli clones was identified that showed proteolytic activity. The gene for the proteolytic enzyme was subcloned into pUC19 and
sequenced, and a database search for homologies revealed it to be a zinc-dependent metalloprotease. The cloned gene included
the intact coding gene for a novel metalloproteinase and its own promoter. It comprised an open reading frame of 1,080 base
pairs, which encodes a protein of 39,490 Da consisting of 359 amino acid residues. A His-Glu-X-X-His sequence, which is a
conserved sequence in the active site of zinc-dependent metalloproteases, was found in the deduced amino acid sequence of
the gene, suggesting that the enzyme is a zinc-dependent metalloprotease. The purified enzyme showed optimal activity at 50°C
for 1 h and pH 7.0. The enzyme activity was inhibited by metal-chelating reagents, such as EDTA, EGTA and 1,10-phenanthroline.
The enzyme hydrolyzed azocasein as well as fibrin. Thus, the enzyme could be useful as a therapeutic agent to treat thrombosis.
The sequence reported in this paper has been deposited in the GenBank database (Accession number: EF100137). 相似文献
996.
Rajesh Kumar Tewari Soo Yeon Lee Eun Joo Hahn Kee Yoeup Paek 《Plant biotechnology reports》2007,1(4):227-235
Nitric oxide (NO) is a diffusible, gaseous signaling molecule. In plants, NO influences growth and development, and it can
also affect plant responses to various stresses. Because NO induces root differentiation and interacts with reactive oxygen
species, we examined the temporal effect of NO elicitation on root growth, saponin accumulation and antioxidant defense responses
in the adventitious roots of mountain ginseng (Panax ginseng). The observations revealed that NO is involved in root growth and saponin production. Elicitation with sodium nitroprusside
(SNP) activated O2
−-generating NADPH oxidase (NOX) activity, which most probably subsequently enhanced growth of adventitious roots of mountain
ginseng. A severe inhibition of NOX activity and decline in dry weight of SNP elicited adventitious roots in the presence
of NOX inhibitor (diphenyl iodonium, DPI), which further supports involvement of NOX in root growth. Enhanced activities of
antioxidant enzymes by SNP appear to be responsible for low H2O2, less lipid peroxidation, and modulation of ascorbate and non-protein thiol statuses in the adventitious roots of mountain
ginseng. Dry mass, saponin content and NOX activity was related with NO content present in adventitious roots of mountain
ginseng. 相似文献
997.
Kallmann syndrome: mutations in the genes encoding prokineticin-2 and prokineticin receptor-2 下载免费PDF全文
Dodé C Teixeira L Levilliers J Fouveaut C Bouchard P Kottler ML Lespinasse J Lienhardt-Roussie A Mathieu M Moerman A Morgan G Murat A Toublanc JE Wolczynski S Delpech M Petit C Young J Hardelin JP 《PLoS genetics》2006,2(10):e175
Kallmann syndrome combines anosmia, related to defective olfactory bulb morphogenesis, and hypogonadism due to gonadotropin-releasing hormone deficiency. Loss-of-function mutations in KAL1 and FGFR1 underlie the X chromosome-linked form and an autosomal dominant form of the disease, respectively. Mutations in these genes, however, only account for approximately 20% of all Kallmann syndrome cases. In a cohort of 192 patients we took a candidate gene strategy and identified ten and four different point mutations in the genes encoding the G protein-coupled prokineticin receptor-2 (PROKR2) and one of its ligands, prokineticin-2 (PROK2), respectively. The mutations in PROK2 were detected in the heterozygous state, whereas PROKR2 mutations were found in the heterozygous, homozygous, or compound heterozygous state. In addition, one of the patients heterozygous for a PROKR2 mutation was also carrying a missense mutation in KAL1, thus indicating a possible digenic inheritance of the disease in this individual. These findings reveal that insufficient prokineticin-signaling through PROKR2 leads to abnormal development of the olfactory system and reproductive axis in man. They also shed new light on the complex genetic transmission of Kallmann syndrome. 相似文献
998.
Young Koung Lee Gyung-Tae Kim In-Jung Kim Jeongmoo Park Sang-Soo Kwak Giltsu Choi Won-Il Chung 《Development (Cambridge, England)》2006,133(21):4305-4314
Plants have diversified their leaf morphologies to adapt to diverse ecological niches. The molecular components responsible for regulating leaf morphology, however, have not been fully elucidated. By screening Arabidopsis activation-tagging lines, we identified a dominant mutant, which we designated longifolia1-1D (lng1-1D). lng1-1D plants were characterized by long petioles, narrow but extremely long leaf blades with serrated margins, elongated floral organs, and elongated siliques. The elongated leaves of the mutant were due to increased polar cell elongation rather than increased cell proliferation. Molecular characterization revealed that this phenotype was caused by overexpression of the novel gene LNG1, which was found to have a homolog, LNG2,in Arabidopsis. To further examine the role of the LNG genes, we characterized lng1 and lng2 loss-of-function mutant lines. In contrast to the elongated leaves of lng1-1D plants, the lng1 and lng2 mutants showed slightly decreased leaf length. Furthermore, the lng1-3 lng2-1 double mutant showed further decreased leaf length associated with less longitudinal polar cell elongation. The leaf widths in lng1-3 lng2-1 mutant plants were similar to those in wild type, implying that the role of LNG1 and LNG2 on polar cell elongation is similar to that of ROTUNDIFOLIA3 (ROT3). However, analysis of a lng1-3 lng2-1 rot3-1 triple mutant and of a lng1-1D rot3-1 double mutant indicated that LNG1 and LNG2 promote longitudinal cell elongation independently of ROT3. Taken together, these findings indicate that LNG1 and LNG2 are new components that regulate leaf morphology by positively promoting longitudinal polar cell elongation independently of ROT3 in Arabidopsis. 相似文献
999.
1000.
Transcriptional profiling reveals a possible role for the timing of the inflammatory response in determining susceptibility to a viral infection 下载免费PDF全文
Ruby T Whittaker C Withers DR Chelbi-Alix MK Morin V Oudin A Young JR Zoorob R 《Journal of virology》2006,80(18):9207-9216
Using a novel cDNA microarray prepared from sources of actively responding immune system cells, we have investigated the changes in gene expression in the target tissue during the early stages of infection of neonatal chickens with infectious bursal disease virus. Infections of two lines of chickens previously documented as genetically resistant and sensitive to infection were compared in order to ascertain early differences in the response to infection that might provide clues to the mechanism of differential genetic resistance. In addition to major changes that could be explained by previously described changes in infected tissue, some differences in gene expression on infection, and differences between the two chicken lines, were observed that led to a model for resistance in which a more rapid inflammatory response and more-extensive p53-related induction of apoptosis in the target B cells might limit viral replication and consequent pathology. Ironically, the effect in the asymptomatic neonatal infection is that more-severe B-cell depletion is seen in the more genetically resistant chicken. Changes of expression of many chicken genes of unknown function, indicating possible roles in the response to infection, may aid in the functional annotation of these genes. 相似文献