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61.
Metallothioneins MTT1 and MTT2 from Tetrahymena thermophila have been characterized. The MTT1 contains mainly characteristic Cys-Cys-Cys and Cys-Cys clusters, but MTT2 contains mainly Cys-X-Cys cluster. Cd16-MTT1 mainly consists of α-helix and β-turns, in contrast, Cd11-MTT2 mainly consists of random coils. Reaction of Cd16-MTT1 and Cd11-MTT2 with nitric oxide leads to intramolecular disulfide bond formation, respectively. Binding stabilities of Cd2+, Hg2+ and Zn2+ to MTT1 are stronger than those to MTT2. Cu2+ can not replace Cd2+ from Cd16-MTT1 complex, but can replace Cd2+ from Cd11-MTT2 complex. The analysis of qRT-PCR revealed MTT2 mRNA levels were 31-fold higher than those of MTT1 under basal conditions. These results further suggest MTT1 possibly play a role in the detoxification of heavy metal ions, and MTT2 may be involved in the homeostasis of copper ions. 相似文献
62.
Mutations in the fumarate hydratase gene cause hereditary leiomyomatosis and renal cell cancer in families in North America 总被引:10,自引:0,他引:10 下载免费PDF全文
Toro JR Nickerson ML Wei MH Warren MB Glenn GM Turner ML Stewart L Duray P Tourre O Sharma N Choyke P Stratton P Merino M Walther MM Linehan WM Schmidt LS Zbar B 《American journal of human genetics》2003,73(1):95-106
Hereditary leiomyomatosis and renal cell cancer (HLRCC) is an autosomal dominant disorder characterized by smooth-muscle tumors of the skin and uterus and/or renal cancer. Although the identification of germline mutations in the fumarate hydratase (FH) gene in European families supports it as the susceptibility gene for HLRCC, its role in families in North America has not been studied. We screened for germline mutations in FH in 35 families with cutaneous leiomyomas. Sequence analysis revealed mutations in FH in 31 families (89%). Twenty different mutations in FH were identified, of which 18 were novel. Of these 20 mutations, 2 were insertions, 5 were small deletions that caused frameshifts leading to premature truncation of the protein, and 13 were missense mutations. Eleven unrelated families shared a common mutation: R190H. Eighty-one individuals (47 women and 34 men) had cutaneous leiomyomas. Ninety-eight percent (46/47) of women with cutaneous leiomyomas also had uterine leiomyomas. Eighty-nine percent (41/46) of women with cutaneous and uterine leiomyomas had a total hysterectomy, 44% at age < or =30 years. We identified 13 individuals in 5 families with unilateral and solitary renal tumors. Seven individuals from four families had papillary type II renal cell carcinoma, and another individual from one of these families had collecting duct carcinoma of the kidney. The present study shows that mutations in FH are associated with HLRCC in North America. HLRCC is associated with clinically significant uterine fibroids and aggressive renal tumors. The present study also expands the histologic spectrum of renal tumors and FH mutations associated with HLRCC. 相似文献
63.
从山东崅屿采集的黄棕壤中分离得到一株具有抗Mn(Ⅱ)和Mn(Ⅱ)氧化双重活性的芽胞杆菌,其最高Mn(Ⅱ)耐受浓度达到130mmol/L,对Mn(Ⅱ)的氧化活性为3.3μmol/(L·d)。通过个体形态与培养特征观测、生理生化反应、G+Cmol%测定和16SrDNA序列比对分析等鉴定,确定该菌株为巨大芽胞杆菌(Bacillus megaterium),命名为MB283。该菌株在添加Mn(Ⅱ)(10mmol/L)条件下比不添加Mn(Ⅱ)表现出相对较快的生长速率。采用高温培养并结合0.01%SDS处理,从MB283菌株筛选到一株发生内生质粒消除的突变株MB287,具有与野生菌株类似的锰耐受活性,且对Mn(Ⅱ)的氧化活性与野生菌株相比无明显改变,表明野生菌株MB283中与锰抗性和锰氧化相关的基因可能是定位于该菌的染色体上。 相似文献
64.
SPOP Promotes Nanog Destruction to Suppress Stem Cell Traits and Prostate Cancer Progression 总被引:1,自引:0,他引:1
65.
Jafar A. Mammadov Wei Chen Ruihua Ren Reetal Pai Wesley Marchione Feyruz Yalçin Hanneke Witsenboer Thomas W. Greene Steven A. Thompson Siva P. Kumpatla 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2010,121(3):577-588
The duplicated and the highly repetitive nature of the maize genome has historically impeded the development of true single
nucleotide polymorphism (SNP) markers in this crop. Recent advances in genome complexity reduction methods coupled with sequencing-by-synthesis
technologies permit the implementation of efficient genome-wide SNP discovery in maize. In this study, we have applied Complexity
Reduction of Polymorphic Sequences technology (Keygene N.V., Wageningen, The Netherlands) for the identification of informative
SNPs between two genetically distinct maize inbred lines of North and South American origins. This approach resulted in the
discovery of 1,123 putative SNPs representing low and single copy loci. In silico and experimental (Illumina GoldenGate (GG)
assay) validation of putative SNPs resulted in mapping of 604 markers, out of which 188 SNPs represented 43 haplotype blocks
distributed across all ten chromosomes. We have determined and clearly stated a specific combination of stringent criteria
(>0.3 minor allele frequency, >0.8 GenTrainScore and >0.5 Chi_test100 score) necessary for the identification of highly polymorphic
and genetically stable SNP markers. Due to these criteria, we identified a subset of 120 high-quality SNP markers to leverage
in GG assay-based marker-assisted selection projects. A total of 32 high-quality SNPs represented 21 haplotypes out of 43
identified in this study. The information on the selection criteria of highly polymorphic SNPs in a complex genome such as
maize and the public availability of these SNP assays will be of great value for the maize molecular genetics and breeding
community. 相似文献
66.
Combinatorial signals of activin/nodal and bone morphogenic protein regulate the early lineage segregation of human embryonic stem cells 总被引:2,自引:0,他引:2
Wu Z Zhang W Chen G Cheng L Liao J Jia N Gao Y Dai H Yuan J Cheng L Xiao L 《The Journal of biological chemistry》2008,283(36):24991-25002
Cell fate commitment of pre-implantation blastocysts, to either the inner cell mass or trophoblast, is the first step in cell lineage segregation of the developing human embryo. However, the intercellular signals that control fate determination of these cells remain obscure. Human embryonic stem cells (hESCs) provide a unique model for studying human early embryonic development. We have previously shown that Activin/Nodal signaling contributes to maintaining pluripotency of hESCs, which are derivatives of the inner cell mass. Here we further demonstrate that the inhibition of Activin/Nodal signaling results in the loss of hESC pluripotency and trophoblast differentiation, similar to BMP4-induced trophoblast differentiation from hESCs. We also show that the trophoblast induction effect of BMP4 correlates with and depends on the inhibition of Activin/Nodal signaling. However, the activation of BMP signaling is still required for trophoblast differentiation when Activin/Nodal signaling is inhibited. These data reveal that the early lineage segregation of hESCs is determined by the combinatorial signals of Activin/Nodal and BMP. 相似文献
67.
68.
Inhibition of mitochondrial complex I improves glucose metabolism independently of AMPK activation 下载免费PDF全文
Wo‐Lin Hou Jun Yin Miriayi Alimujiang Xue‐Ying Yu Li‐Gen Ai Yu‐qian Bao Fang Liu Wei‐Ping Jia 《Journal of cellular and molecular medicine》2018,22(2):1316-1328
Accumulating evidences showed metformin and berberine, well‐known glucose‐lowering agents, were able to inhibit mitochondrial electron transport chain at complex I. In this study, we aimed to explore the antihyperglycaemic effect of complex I inhibition. Rotenone, amobarbital and gene silence of NDUFA13 were used to inhibit complex I. Intraperitoneal glucose tolerance test and insulin tolerance test were performed in db/db mice. Lactate release and glucose consumption were measured to investigate glucose metabolism in HepG2 hepatocytes and C2C12 myotubes. Glucose output was measured in primary hepatocytes. Compound C and adenoviruses expressing dominant negative AMP‐activated protein kinase (AMPK) α1/2 were exploited to inactivate AMPK pathway. Cellular NAD+/NADH ratio was assayed to evaluate energy transforming and redox state. Rotenone ameliorated hyperglycaemia and insulin resistance in db/db mice. It induced glucose consumption and glycolysis and reduced hepatic glucose output. Rotenone also activated AMPK. Furthermore, it remained effective with AMPK inactivation. The enhanced glycolysis and repressed gluconeogenesis correlated with a reduction in cellular NAD+/NADH ratio, which resulted from complex I suppression. Amobarbital, another representative complex I inhibitor, stimulated glucose consumption and decreased hepatic glucose output in vitro, too. Similar changes were observed while expression of NDUFA13, a subunit of complex I, was knocked down with gene silencing. These findings reveal mitochondrial complex I emerges as a key drug target for diabetes treatment. Inhibition of complex I improves glucose homoeostasis via non‐AMPK pathway, which may relate to the suppression of the cellular NAD+/NADH ratio. 相似文献
69.
千山油松年轮宽度年表的建立及其与气候的关系 总被引:5,自引:0,他引:5
以千山油松为样本,建立了年轮宽度标准化年表、差值年表和自回归年表.结果表明,油松年轮宽度与5—7和9—11月温度指标的相关性较高,且与低温呈正相关,其中与7月的极端最低温、9月的平均最低温显著相关.3种年表与上年12月和当年1月的极端最低温、1月的平均最低温呈显著相关,且其与全年、上年12月、当年5月的降水量显著相关,与4月的降水量极显著相关.油松与水汽压、相对湿度的月和年指标均有较强的相关性.蒸发的年指标和绝大部分月指标对油松生长具有负效应,其中4—7月最明显.油松年表的窄化突变佐证了1800年以来的30次主要的旱灾年历史记录.千山油松的生长受全球或半球尺度气候变化的影响.年表与太阳活动存在显著的11、23和50年左右的公共周期,与地磁指标在10、20和45年左右存在共同的周期变化. 相似文献
70.
西藏中部退化土壤在不同培肥措施下的肥力特征 总被引:1,自引:1,他引:1
于西藏中部春播条件下就不同培肥方式对退化土壤物理、化学和生物性质的影响以及土壤肥力因子间的相互关系进行了研究。结果表明 ,化肥、有机肥 ,特别是有机 -无机肥配合施用在协调土壤环境 ,促进以细菌为主导的土壤微生物繁殖以及土壤有机质、土壤团粒结构形成和土壤养分转化等方面具有重要作用 ;退化土壤物理、化学和生物性质呈现出变化特征的相对一致性 ,并在总体上呈现出较为明显的恢复态势 ,突出地反映了高原高寒以及干旱、半干旱条件下退化土壤所具有的在相对较短的时间内实现肥力恢复及结构重建的可能性及其潜力。石灰性土壤条件下 ,耕层土壤有机质以及不同土层全氮、有效氮、全磷、有效磷的绝对增长量较大。同时 ,不同培肥方式对不同土层土壤真菌、固氮菌以及耕层土壤放线菌的繁殖普遍具有不同程度的抑制作用 ;不同土层土壤固氮菌与纤维素分解菌均呈负相关。 相似文献