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991.
992.
Relations of mineral-soil C and N to climate and texture: regional differences within the conterminous USA 总被引:4,自引:0,他引:4
Soil is a prominent component of terrestrial C and N budgets. Soil C and N pools are influenced by, and may reciprocally influence,
many environmental factors. Our objective was to determine the quantitative relations of surface mineral-soil organic C, N,
and C/N ratios to climate and soil texture across seven ecological regions that make up the conterminous USA. Up to 608 soil
profiles per region and their corresponding climates were evaluated with regression analysis. The organic C pool (kg C m−2) in the upper 20 cm of mineral soil was positively related to mean annual precipitation, evapotranspiration and clay content
in all regions. It was negatively related to a temperature/precipitation index in all regions and negatively related to mean
annual temperature, except in the northwest temperate forest region. Soil C/N ratios were negatively related to clay or silt
content in all regions. These relations are consistent with concepts of moisture and temperature controls on detrital production,
differential effects of temperature on detrital production and decomposition, and stabilization of organic matter by clay
and silt. Differences in quantitative relations among regions may be related to vegetation-composition effects on soil organic
matter processes, clay mineralogy, and faunal mixing of surface organic horizons with mineral soil. Regional differences also
occurred in the importance of climate vs. soil texture in explaining the variability in soil C. The regional differences indicate
the importance of using region-specific, rather than generalized, equations for projecting long-term soil responses to climate
change and for conducting ecosystem-model calibration or validation. 相似文献
993.
Endostatin gene therapy enhances the efficacy of paclitaxel to suppress breast cancers and metastases in mice 总被引:5,自引:0,他引:5
Li J Dong X Xu Z Jiang X Jiang H Krissansen GW Sun X 《Journal of biomedical science》2008,15(1):99-109
Chemotherapy combined with antiangiogenic therapy is more effective than chemotherapy alone. The aim of this study was to
investigate whether endostatin, a potent anti-angiogenic agent, could enhance the efficacy of paclitaxel to combat breast
cancer. An expression plasmid encoding mouse endostatin (End-pcDNA3.1) was constructed, which produced intense expression
of endostatin and inhibited angiogenesis in the chorioallantoic membrane assay. 4T1 breast tumors were established in BALB/c
mice by subcutaneous injection of 1 × 105 4T1 cells. The End-pcDNA3.1 plasmid diluted in the transfection reagent FuGENETM was injected into the tumors (around 100 mm2), and paclitaxel was injected i.p. into the mice. Endostatin gene therapy synergized with paclitaxel in suppressing the growth
of 4T1 tumors and their metastasis to the lung and liver. Both endostatin and paclitaxel inhibited tumor angiogenesis and
induced cell apoptosis. Despite the finding that endostatin was superior to paclitaxel at inhibiting tumor angiogenesis, paclitaxel
was nevertheless more effective at inducing tumor apoptosis. The combination of paclitaxel and endostatin was more effective
in suppressing tumor growth, metastases, angiogenesis, and inducing apoptosis than the respective monotherapies. The combinational
therapy with endostatin and paclitaxel warrants future investigation as a therapeutic strategy to combat breast cancer. 相似文献
994.
The association between angiotensin-converting enzyme insertion/deletion (ACE I/D) polymorphism and risk of myocardial infarction (MI) has been extensively studied. However, the results were in controversy. This study aimed to explore the association between ACE I/D polymorphism and risk of MI by using a meta-analysis. We retrieved the following databases to indentify eligible studies: Medline, Embase, ISI, VIP, CBM and Wan Fang database. The latest update was 10th May, 2012. Odds ratio and 95% confidence interval (95% CI) were used to present the strength of the association. A total of 40 case–control studies with 34 993 participants were included. Overall, D allele of ACE I/D polymorphism was significantly associated with an increased risk of MI in genetic comparison models (OR (95% CI): 1.41 (1.22–1.64) for DD vs. II; 1.11 (1.01–1.21) for ID vs. II; 1.23 (1.10–1.37) for D carriers vs. II; 1.28 (1.15–1.43) for DD vs. I carriers and 1.06 (1.02–1.10) for D carriers vs. I carriers). Subgroup analyses, according to ethnicities and countries of participants also indicated that D allele was significantly associated with an increased risk of MI in Asians (especially for Chinese) and Caucasians (especially for English, French, Germans and Italians) (OR (95% CI) of DD vs. ID + II: 2.11 (1.65–2.70) for Asians and 1.15 (1.05–1.27) for Caucasians). In conclusion, this meta-analysis indicated that D allele of ACE I/D polymorphism was a possible risk factor for MI incidence for both Asians and Caucasians. 相似文献
995.
Mechanocomputational techniques in conjunction with artificial intelligence (AI) are revolutionizing the interpretations of the crucial information from the medical data and converting it into optimized and organized information for diagnostics. It is possible due to valuable perfection in artificial intelligence, computer aided diagnostics, virtual assistant, robotic surgery, augmented reality and genome editing (based on AI) technologies. Such techniques are serving as the products for diagnosing emerging microbial or non microbial diseases. This article represents a combinatory approach of using such approaches and providing therapeutic solutions towards utilizing these techniques in disease diagnostics. 相似文献
996.
Chen X Li Y Wei K Li L Liu W Zhu Y Qiu Z He F 《The Journal of biological chemistry》2003,278(49):49022-49030
Hepatopoietin (HPO) is a novel hepatotrophic growth factor that stimulates hepatocyte proliferation by two pathways. In the first, intracellular HPO specifically modulates the activator protein-1 (AP-1) pathway through JAB1 (Jun activation domain-binding protein 1), whereas in the second, extracellular HPO triggers the mitogen-activated protein kinase pathway by binding its specific receptor on the cell surface. In this report we demonstrate that HPO is a flavin-linked sulfhydryl oxidase, and the invariant CXXC (Cys-Xaa-Xaa-Cys) motif in HPO is essential for the enzyme activity of HPO but not for its dimerization nor for its binding ability with JAB1. Two intramolecular disulfides were identified in HPO by mass spectrometry, one of which is formed by the redox CXXC cysteine residues. HPO site-directed mutants (Cys/Ser) at active sites, which lost sulfhydryl oxidase activity, could not increase c-Jun phosphorylation and failed to potentiate JAB1-mediated AP-1 activation. However, the mutants still have mitogenic stimulation and mitogen-activated protein kinase activation effects on HepG2 cells. Thus, it can be concluded that the potentiation role of HPO on AP-1 is dependent on its sulfhydryl oxidase activity. 相似文献
997.
Inhibition of tumour necrosis factor (TNF)-alpha with biological molecules has proven an effective treatment for rheumatoid
arthritis, achieving a 20% improvement in American College of Rheumatology score in up to 65% of patients. The main drawback
to these and many other biological treatments has been their expense, which has precluded their widespread application. Biological
molecules could alternatively be delivered by gene therapy as the encoding DNA. We have developed novel plasmid vectors termed
pGTLMIK and pGTTMIK, from which luciferase and a dimeric TNF receptor II (dTNFR) are respectively expressed in a doxycycline
(Dox)-regulated manner. Regulated expression of luciferase from the self-contained plasmid pGTLMIK was examined in vitro in a variety of cell lines and in vivo following intramuscular delivery with electroporation in DBA/1 mice. Dox-regulated expression of luciferase from pGTLMIK
of approximately 1,000-fold was demonstrated in vitro, and efficient regulation was observed in vivo. The vector pGTTMIK encoding dTNFR was delivered by the same route with and without administration of Dox to mice with collagen-induced
arthritis. When pGTTMIK was delivered after the onset of arthritis, progression of the disease in terms of both paw thickness
and clinical score was inhibited when Dox was also administered. Vectors with similar regulation characteristics may be suitable
for clinical application. 相似文献
998.
SKPI(shrimp Kunitz-type protease inhibitor)是日本囊对虾(Marsupenaeus japonicus)体内的一个小分子多肽, 含有一个Kunitz型结构域, 属于丝氨酸蛋白酶抑制剂。目前已知丝氨酸蛋白酶抑制剂在节肢动物免疫系统中起着非常重要的作用, 为了了解SKPI在对虾天然免疫系统中的作用, 首先对其进行了重组表达。从日本囊对虾肝胰腺中扩增skpi的cDNA片段, 插入改造后的pPIC9K酵母表达载体, 获得的重组质粒转化至毕赤酵母GS115进行表达。由于改造的pPIC9K载体加入了6-His标签, 因此利用Ni?Sepharose?High?Performance对SKPI进行了高效纯化。初步的活性研究表明, 重组表达的SKPI能特异性地抑制胰蛋白酶的水解活性。 相似文献
999.
1000.
Lin CT Tsai YC He L Calizo R Chou HH Chang TC Soong YK Hung CF Lai CH 《Journal of biomedical science》2006,13(4):481-488
Summary The HPV oncoproteins E6 and E7 are consistently expressed in HPV-associated cancer cells and are responsible for their malignant transformation. Therefore, HPV E6 and E7 are ideal target antigens for developing vaccines and immunotherapeutic strategies against HPV-associated neoplasms. Recently, it has been demonstrated that codon optimization of the HPV-16 E7 gene resulted in highly efficient translation of E7 and increased the immunogenicity of E7-specific DNA vaccines. Since vaccines targeting E6 also represent an important strategy for controlling HPV-associated lesions, we developed a codon-optimized HPV-16 E6 DNA vaccine (pNGVL4a-E6/opt) and characterized the E6-specific CD8+ T cell immune responses as well as the protective and therapeutic anti-tumor effects in vaccinated C57BL/6 mice. Our data indicated that transfection of human embryonic kidney cells (293 cells) with pNGVL4a-E6/opt resulted in highly efficient translation of E6. In addition, vaccination with pNGVL4a-E6/opt significantly enhanced E6-specific CD8+ T cell immune responses in C57BL/6 mice. Mice vaccinated with pNGVL4a-E6/opt are able to generate potent protective and therapeutic antitumor effects against challenge with E6-expressing tumor cell line, TC-1. Thus, DNA vaccines encoding a codon-optimized HPV-16 E6 may be a promising strategy for improving the potency of prophylactic and therapeutic HPV vaccines with potential clinical implications. 相似文献