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41.
Hiroshi Fukamachi Shinko Kato Makoto Asashima Masao Ichinose Yasuhito Yuasa 《Development, growth & differentiation》2013,55(9):786-791
The importance of epithelial–mesenchymal interaction on the development of gastro‐intestinal (GI) organs has been repeatedly reported, but its molecular mechanism has not been fully understood though several factors including hepatocyte growth factor and endothelin‐3 have been shown to mediate it. Activins have been demonstrated to play important roles in the regulation of organogenesis in vertebrates, but their roles in the regulation of growth and differentiation of GI organs remain to be solved. In the present study, we examined expression of activins in developing rat GI tract, and found that inhibin bA encoding activin A was specifically expressed by GI mesenchymes, while inhibin bB encoding activin B was expressed by both epithelial and mesenchymal components. We then examined the effect of activin A on the growth of fetal rat GI epithelial cells in primary culture. We found that activin A inhibited the growth of forestomach and glandular stomach epithelial cells while it stimulated the growth of colonic epithelial cells. These results suggest that activin A secreted from GI mesenchymes region‐specifically regulates the growth of attaching epithelial cells. We thus conclude that activin A mediates epithelial‐mesenchymal interaction in the developing GI tract. 相似文献
42.
Makoto Tajima Nobuko Sekiguchi Masao Fujimaki 《Bioscience, biotechnology, and biochemistry》2013,77(2):319-320
High phosphate accumulating bacteria were isolated by autoradiography. One isoate, Arthrobacter globiformis PAB-6 accumulated phosphate intracellularly at 20% of dry cell mass in a simple synthetic medium. This amount was 3~7 times higher than type cultures examined. Almost no phosphate was released into the medium after cessation of growth. Fifty percent of total intracellular phosphate was fractionated as nucleic acids, while 20% each was recovered from cold PCA soluble fractions and polyphosphate fractions. The large content of nucleic acids in this bacterium appeared due to increased RNA content, specifically 4 S RNA fraction. 相似文献
43.
Akihiro Okitani Atsushi Suzuki Ryung Yang Masao Fujimaki 《Bioscience, biotechnology, and biochemistry》2013,77(12):2135-2141
The effect of cathepsin D and pepsin treatment on rabbit myofibril was studied by measuring the amount of proteolytic products and Mg-enhanced ATPase activity.When myofibril was treated with cathepsin D at 3°C and pH 5.0 or 5.5, a little but detectable amount of nonprotein nitrogenous compounds was released. However, there was no change in ATPase activity of myofibril, though treated with cathepsin D of higher units than assumed to be in muscle.When myofibril was treated with pepsin under the same condition as used above, there was an increase in KCl-concentration dependence of ATPase activity followed by a decrease in the maximal value of ATPase activity.From the present results, it was concluded that cathepsin D might not take a main role on the post-mortem degradation of myofibril. 相似文献
44.
To elucidate the formation mechanism of N,N′-dialkylpyrazine cation radical during browning reaction of sugars with amino compounds, main products in an early stage of the reaction were determined quantitatively by TLC and GLC. It was shown that the Schiff base, two-carbon fragmental product of sugar, the free radical and deoxyosone were successively produced prior to the browning. Polarographical measurements indicated that the radical formation was induced by the production of some reducing substances in the reaction mixture. These results suggest that the free radical was formed by the reduction of N,N′-dialkylpyrazinium; a compound, which demonstrated to have a strong activity to browning, might be formed by condensation of two-carbon enaminol followed by oxidation. 相似文献
45.
In Japan, the green seaweed Monostroma is an important source of humanfood. Monostroma nitidum Wittrock (Japanese name: hitoegusa)
is cultivated in brackish waters and estuaries of central to southern Japan. The green seaweed Monostroma grows in the brackish
water area in the upper part of the intertidal zone in the warm waters. Artificial seed culture began with the collection
of many gametes in April. The resultant zygotes were allowed to adhere to plastic settlement boards (20 cm long and 10 cm
wide). The zygoteboards were then cultured in tanks (1 ×2 ×0.5 m) with fertiliser in a controlled growth room (10–87 μmol
photon m-2s-1). The cultivated zygotes on the board in the indoor tanks gradually increased in size from 10 to 40 μm in diameter during
May to early August. Zygote growth became slowed at the end of August. The zygotesmatured in early September, and the plates
were transferred into culture tanks in a dark room for dark treatment. Maturation of the zygote was promoted by providing
dark conditions for two weeks. The production of a concentrated zoospore solution from the mature blades was achieved by adding
fresh water at temperature 2–3 °C above that of the seeding vats. Zoospores were released in large numbers when exposed to
strong irradiance of 100 μmol photon m-2 s-1 for 30 min. The zygotes produced flat unicellular fronds at the germling stage. The technology of artificial seed culture
and zoospore release from the zygotes is based mainly on these experiments.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
46.
Yumiko Nakagaito Motonobu Satoh Haruhiko Kuno Toshi Iwama Masao Takeuchi Akira Hakura Touho Yoshida 《In vitro cellular & developmental biology. Animal》1998,34(7):585-592
Summary We have established a multipotent clonal cell line, named MEB5, from embryonic mouse forebrains after the infection of a retrovirus
carrying E7 oncogene of human papillomavirus type 16. MEB5 cells proliferated in serum-free, epidermal growth factor (EGF)-supplemented
medium. They expressed markers for neural precursor cells (nestin, A2B5, and RC1) and did not express markers for neurons
(class III β-tubulin), astrocytes (glial fibrillary acidic protein), and oligodendrocytes (galactocerebroside). MEB5 cells
were stably maintained in an undifferentiated state with a diploid karyotype in the presence of EGF. When they were deprived
of EGF, about 50% of the cells died due apoptosis within 24 h. The remaining cells differentiated into neurons, astrocytes,
or oligodendrocytes within 2 wk. The newly developed cells with neuronal morphology were immunoreactive for γ-aminobutyric
acid and exhibited neuronal electrophysiological properties. When MEB5 cells were treated with leukemia inhibitory for 7 d,
they were induced to differentiate exclusively into astrocytes. These results inducate that MEB5 is a cell line with characteristics
of EGF-dependent, multipotent neural precursor cells. This cell line should provide a good model system to study the mechanisms
of survival, proliferation, and differentiation of the multipotent precursor cells in the central nervous system. 相似文献
47.
Loc Van Nguyen Ryoji Takahashi Stephen Mwangi Githiri Tito O. Rodriguez Nobuko Tsutsumi Sayuri Kajihara Takasi Sayama Masao Ishimoto Kyuya Harada Keisuke Suematsu Tomomi Abiko Toshihiro Mochizuki 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2017,130(4):743-755
Key message
Greatest potential, QTLs for hypoxia and waterlogging tolerance in soybean roots were detected using a new phenotypic evaluation method.Abstract
Waterlogging is a major environmental stress limiting soybean yield in wet parts of the world. Root development is an important indicator of hypoxia tolerance in soybean. However, little is known about the genetic control of root development under hypoxia. This study was conducted to identify quantitative trait loci (QTLs) responsible for root development under hypoxia. Recombinant inbred lines (RILs) developed from a cross between a hypoxia-sensitive cultivar, Tachinagaha, and a tolerant landrace, Iyodaizu, were used. Seedlings were subjected to hypoxia, and root development was evaluated with the value change in root traits between after and before treatments. We found 230 polymorphic markers spanning 2519.2 cM distributed on all 20 chromosomes (Chrs.). Using these, we found 11 QTLs for root length (RL), root length development (RLD), root surface area (RSA), root surface area development (RSAD), root diameter (RD), and change in average root diameter (CARD) on Chrs. 11, 12, 13 and 14, and 7 QTLs for hypoxia tolerance of these root traits. These included QTLs for RLD and RSAD between markers Satt052 and Satt302 on Chr. 12, which are important markers of hypoxia tolerance in soybean; those QTLs were stable between 2 years. To validate the QTLs, we developed a near-isogenic line with the QTL region derived from Iyodaizu. The line performed well under both hypoxia and waterlogging, suggesting that the region contains one or more genes with large effects on root development. These findings may be useful for fine mapping and positional cloning of gene responsible for root development under hypoxia.48.
Acute and fulminant liver failure induced by viral hepatitis, alcohol or other hepatotoxic drugs are associated with tumor necrosis factor (TNF) production. D-Galactosamine (D-GalN) and lipopolysaccharide (LPS)-induced liver injury is an experimental model of fulminant hepatic failure. In this model, TNF-alpha plays a central role in the pathogenesis of D-GalN/LPS-induced liver injury in mice. Y-40138, N-[1-(4-[4-(pyrimidin-2-yl)piperazin-1-yl]methyl phenyl)cyclopropyl] acetamide.HCl inhibits TNF-alpha and augments interleukin (IL)-10 production in LPS-injected mice in plasma. In the present study, we examined the effect of Y-40138 on D-GalN/LPS-induced hepatitis. Y-40138 (10mg/kg, i.v.) significantly suppressed TNF-alpha and monocyte chemoattractant protein-1 (MCP-1) production and augmented IL-10 production in plasma. In addition, Y-40138 significantly inhibited TNF-alpha production induced by direct interaction between human T lymphocytes and macrophages. Y-40138 suppressed plasma alanine transaminase (ALT) elevation and improved survival rate in D-GalN/LPS-injected mice, and it is suggested that the protective effect of Y-40138 on hepatitis may be mediated by inhibition of TNF-alpha and MCP-1, and/or augmentation of IL-10. This compound is expected to be a new candidate for treatment of cytokine and/or chemokine-related liver diseases such as alcoholic hepatitis. 相似文献
49.
Human T-cell leukemia virus type I (HTLV-I) is a causative virus of adult T-cell leukemia (ATL). ATL is a highly aggressive neoplastic disease of CD4 positive T lymphocyte, which is featured by the pleomorphic tumor cells with hypersegmented nuclei, called " flower cell". HTLV-I increases its copy number by clonal proliferation of the host cells, not by replication of the virus. Therefore, HTLV-I eventually induces ATL. Tax, encoded by HTLV-I pX region, has been recognized as a protein that plays a central role of the transformation of HTLV-I-infected cells by its pleiotropic actions. However, fresh ATL cells frequently lose Tax protein expression by several mechanisms. Recently, HBZ was identified in the complementary strand of HTLV-I and it is suggested that HBZ is a critical gene in leukemogenesis. Furthermore, there is a long latency period before onset of ATL, indicating the multistep mechanisms of leukemogenesis. Therefore, it is suggested that multiple factors, such as viral proteins, genetic and epigenetic changes of host genome, and immune status of the hosts, could be implicated in leukemogenesis of ATL. 相似文献
50.
We recently reported that primary fetal bovine Kidney (PFBK) cells were consistently more sensitive to the cytotoxic effects of fusarium T-2 toxin than Madin-Darby bovine kidney (MDBK) cells in culture. The present report examined the influence of T-2 on selected biochemical parameters of these two culture types. T-2 toxin inhibited incorporation of labeled thymidine, uridine, and leucine in both culture types; at lower concentrations of the toxin, PFBK cells were affected to a greater extent than MDBK cells. T-2 toxin inhibited both the transport of thymidine as well as thymidine incorporation into macromolecules in MDBK cells during initial periods, but did not affect uridine incorporation. The cellular enzymes, K+- dependent phosphatase and succinic dehydrogenase were inhibited in MDBK but not in PFBK cultures; acid phosphatase was not influenced in either culture types. In a cell-free system none of the above enzymes were affected by T-2 until the toxin concentration exceeded 10?5M. 相似文献