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131.
Diarrhea-inducing activity of avian rotavirus NSP4 glycoproteins, which differ greatly from mammalian rotavirus NSP4 glycoproteins in deduced amino acid sequence in suckling mice 总被引:5,自引:0,他引:5 下载免费PDF全文
Avian rotavirus NSP4 glycoproteins expressed in Escherichia coli acted as enterotoxins in suckling mice, as did mammalian rotavirus NSP4 glycoproteins, despite great differences in the amino acid sequences. The enterotoxin domain of PO-13 NSP4 exists in amino acid residues 109 to 135, a region similar to that reported in SA11 NSP4. 相似文献
132.
X-Linked inhibitor of apoptosis protein is involved in mutant SOD1-mediated neuronal degeneration 总被引:4,自引:0,他引:4
Ishigaki S Liang Y Yamamoto M Niwa J Ando Y Yoshihara T Takeuchi H Doyu M Sobue G 《Journal of neurochemistry》2002,82(3):576-584
Mutations in the superoxide dismutase 1 (SOD1) gene cause the degeneration of motor neurons in familial amyotrophic lateral sclerosis (FALS). An apoptotic process including caspase-1 and -3 has been shown to participate in the pathogenesis of FALS transgenic (Tg) mouse model. Here we report that IAP proteins, potent inhibitors of apoptosis, are involved in the FALS Tg mouse pathologic process. The levels of X-linked inhibitor of apoptosis protein (XIAP) mRNA and protein were significantly decreased in the spinal cord of symptomatic G93A-SOD1 Tg mice compared with littermates. In contrast, the levels of cIAP-1 mRNA and protein were increased in symptomatic G93A-SOD1 Tg mice, whereas the levels of cIAP-2 mRNA and protein were unchanged. In situ hybridization showed that the expression of XIAP was remarkably reduced in the motor neurons of Tg mice, and the expression of cIAP-1 was strongly increased in the reactive astrocytes of Tg mice. Overexpression of XIAP markedly inhibited the cell death and caspase-3 activity in the neuro2a cells expressing mutant SOD1. Deletional mutant analysis revealed that the N-terminal domain of XIAP, the BIR1-2 domains, was essential for this inhibitory activity. These results suggest that XIAP plays a role in the apoptotic mechanism in the progression of disease in mutant SOD1 Tg mice and holds therapeutic possibilities for FALS. 相似文献
133.
Yanagita M Shimabukuro Y Nozaki T Yoshimura N Watanabe J Koide H Terakura M Saho T Takedachi M Jang MH Kiyono H Murakami S 《Biochemical and biophysical research communications》2002,297(2):329-334
To investigate the biological activity of epithelial cells in view of host defense, we analyzed the mRNA expression of inducible NOS (iNOS) as well as NO production by human gingival epithelial cells (HGEC) stimulated with IL-15. RT-PCR analysis revealed that HGEC expressed IL-15 receptor alpha-chain mRNA. In addition, stimulation with IL-15 enhanced iNOS expression by HGEC through an increase of both mRNA and protein levels. Moreover, IL-15 up-regulated the production of NO(2)(-)/NO(3)(-), a NO-derived stable end product, from HGEC. The enhanced NO production by IL-15 was inhibited by AMT, an iNOS-specific inhibitor. These results suggest that IL-15 is a potent regulator of iNOS expression by HGEC and involved in innate immunity in the mucosal epithelium. 相似文献
134.
Toshiyuki Yamamoto Kyoji Tasaki Yoshio Sugawara Akira Tonosaki 《The Journal of cell biology》1965,25(2):345-359
The fine structure of the visual and the supporting cells and of the blood capillaries in the octopus retina is described. Lamellated structures contained in the proximal segment of the visual cell consist of compact arrays of dense membranes each of which is quintuple-layered and divides at its margins into two thinner sheets or membranes which are connected directly with the agranular or granular endoplasmic reticulum. Proximal to the deeper extremities of the rhabdomeres, the lateral plasma membranes of two adjoining visual cells contact each other forming a quintuple-layered compound membrane, which results in occlusion of the intercellular space. The central layer of the compound membrane is of high density, so that the membrane, as a whole, appears to be a single thick layer at low magnifications. The supporting cells are connected with the neighboring visual cells by two types of junctions. Long slender processes extend from the supporting cells to the surface of the retina through narrow spaces among the distal segments of the visual cells. The capillary endothelial cells are characterized by luminal surfaces irregularly contoured and by lateral surfaces elaborately interdigitated. The functional significance of the close contact between adjoining visual cells is discussed. 相似文献
135.
Yasufumi Kaneda Helene Hayes Tsuyoshi Uchida Michihiro C. Yoshida Yoshio Okada 《Chromosoma》1987,95(1):8-12
A human-mouse hybrid segregant HM76Dd40-6 with new characteristics was derived from the hybrid cell line HM76Dd containing human chromosome 19 as the only human chromosome. Three virus sensitivities located on human chromosome 19 (PVS, E11S and RDRC) were lost in HM76Dd40-6, while six other genes (C3, LDLR, EF2, GPI, PEPD and MANB) were retained. Cytogenetic analysis and in situ hybridization using human or mouse repeated sequences as probes showed that the region q13.1-qter of human chromosome 19 had been replaced by a fragment of mouse chromosome. Our results permit further regional assignment for the following five genes on human chromosome 19: GPI in the region cen-q12, MANB in p13.2-q12, E11S and RDRC in q13.1-qter, and EF2 in pter-q12. 相似文献
136.
Jo Kitawaki Shigeo Inoue Takaya Tamura Takara Yamamoto Hideo Honjo Tadayoshi Higashiyama Yoshio Osawa Hiroji Okada 《The Journal of steroid biochemistry and molecular biology》1993,45(6):485-491
To clarify whether cigarette smoking during pregnancy causes an organic alteration in placental estrogen producing ability, we determined the catalytic activity of aromatase by the tritiated water assay, and tissue level of aromatase cytochrome P-450 (P-450arom) by the specific enzyme-linked immunosorbent assay, in placental samples from nonsmokers and smokers. As pregnancy progressed, both aromatase activity and P-450arom concentration increased in placentas from nonsmokers and smokers. However, the gradient of the increase was significantly less in heavy smokers (20 cigarettes a day) than in normal and moderate smokers (<20 cigarettes a day). At term, the mean aromatase activity and P-450arom concentration in placentas from heavy smokers were significantly lower than in nonsmokers and moderate smokers, while aromatase activity per P-450arom (turnover rate) and the mean placental weight were comparable among the three groups. In contrast, the ratio of aryl hydrocarbon hydroxylase activity to aromatase activity was higher in placentas from heavy smokers. Immunohistochemical studies showed that P-450arom was localized in the cytoplasm of syncytiotrophoblasts of chorionic villi in placentas from both nonsmokers and smokers. These results suggest that the induction of placental P-450arom during gestation is suppressed by maternal smoking, resulting in a reduction in estrogen producing ability, while placental xenobiotic P-450 is induced. 相似文献
137.
Aucuba japonica varieties are common evergreen understory shrubs in Japan.Aucuba japonica var.borealis is distributed on the Sea of Japan side of Honshu and Hokkaido where heavy snow cover lasts for more than 3 months in winter.Aucuba japonica var.japonica is distributed in areas with shallow or no snow on the Pacific Ocean side of Honshu and Shikoku. The ecophysiological characteristics
of var.borealis were compared with those of var.japonica to examine the effects of heavy and long-term snow cover on the life cycle of var.borealis. Shoots of both varieties were shaded in crushed ice for 110 days, but their photosynthetic activities, chlorophyll contents
and the chlorophylla/b ratio was not affected. The leaves of var.borealis were no less frost tolerant than those of var.japonica. In spite of the difference in environmental factors, both varieties had similar characteristics in seasonal changes of photosynthesis,
respiration and chlorophylla/b ratio. These results suggest that var.japonica could survive in areas with heavy snow where it does not normally occur. Leaf net production (LNP) was estimated based on
the microclimatic data and seasonal photosynthetic and respiration rates. The difference in the annual LNP between the two
varieties was equivalent to the difference in the LNP during the snow season. One of the major effects of snow cover is to
interrupt and reduce the production period of var.borealis. 相似文献
138.
Miyamoto Y Banno Y Yamashita T Fujimoto T Oi S Moritoh Y Asakawa T Kataoka O Takeuchi K Suzuki N Ikedo K Kosaka T Tsubotani S Tani A Funami M Amano M Yamamoto Y Aertgeerts K Yano J Maezaki H 《Bioorganic & medicinal chemistry》2011,19(1):172-185
We have previously discovered nicotinic acid derivative 1 as a structurally novel dipeptidyl peptidase IV (DPP-4) inhibitor. In this study, we obtained the X-ray co-crystal structure between nicotinic acid derivative 1 and DPP-4. From these X-ray co-crystallography results, to achieve more potent inhibitory activity, we targeted Arg125 as a potential amino acid residue because it was located near the pyridine core, and some known DPP-4 inhibitors were reported to interact with this residue. We hypothesized that the guanidino group of Arg125 could interact with two hydrogen-bond acceptors in a bidentate manner. Therefore, we designed a series of 3-pyridylacetamide derivatives possessing an additional hydrogen-bond acceptor that could have the desired bidentate interaction with Arg125. We discovered the dihydrochloride of 1-{[5-(aminomethyl)-2-methyl-4-(4-methylphenyl)-6-(2-methylpropyl)pyridin-3-yl]acetyl}-l-prolinamide (13j) to be a potent and selective DPP-4 inhibitor that could interact with the guanidino group of Arg125 in a unique bidentate manner. 相似文献
139.
Hirotoshi Motoda Takayuki Sasaki Yoshio Kano Peter R Ryan Emmanuel Delhaize Hideaki Matsumoto Yoko Yamamoto 《Plant signaling & behavior》2007,2(6):467-472
The wheat ALMT1 gene encodes an aluminum (Al)-activated malate transport protein which confers Al-resistance. We investigated the membrane topology of this plasma-membrane localized protein with immunocytochemical techniques. Several green fluorescent protein (GFP)-fused and histidine (His)-tagged chimeras of ALMT1 were prepared based on a computer-predicted secondary structure and transiently expressed in cultured mammalian cells. Antibodies raised to polypeptide epitopes of ALMT1 were used in conjunction with the antibody to the His-tags to determine the topology of ALMT1. This study shows that the ALMT1 protein contains six transmembrane domains with the amino and carboxyl termini located on the extracellular side of the plasma membrane.Key Words: ALMT1, aluminum resistance, immunofluorescent staining, malate transporter, topology, Triticum aestivum 相似文献
140.
Yoshio Goshima Tadashi Kawakami Hideaki Hori Yoshinobu Sugiyama Shuichi Takasawa Yoko Hashimoto Masako Kagoshima-Maezono Toshifumi Takenaka Yoshimi Misu Stephen M. Strittmatter 《Developmental neurobiology》1997,33(3):316-328
Chick collapsin-1, a member of the semaphorin family, has been implicated in axonal pathfinding as a repulsive guidance cue. Collapsin-1 induces growth cone collapse via a pathway which may include CRMP-62 and heterotrimeric G proteins. CRMP-62 protein is related to UNC-33, a nematode neuronal protein required for appropriately directed axonal extension. Mutations in unc-33 affect neural microtubules, the basic cytoskeletal elements for axoplasmic transport. Using computer-assisted video-enhanced differential interference contrast microscopy, we now demonstrate that collapsin-1 potently promotes axoplasmic transport. Collapsin-1 doubles the number of antero- and retrograde-transported organelles but not their velocity. Collapsin-1 decreases the number of stationary organelles, suggesting that the fraction of time during which a particle is moving is increased. Collapsin-1-stimulated transport occurs by a mechanism distinct from that causing growth cone collapse. Pertussis toxin (PTX) but not its B oligomer blocks collapsin-induced growth cone collapse. The holotoxin does not affect collapsin-stimulated axoplasmic transport. Mastoparan and a myelin protein NI-35 induce PTX-sensitive growth cone collapse but do not stimulate axoplasmic transport. These results provide evidence that collapsin has a unique property to activate axonal vesicular transport systems. There are at least two distinct pathways through which collapsin exerts its actions in developing neurons. © 1997 John Wiley & Sons, Inc. J Neurobiol 33: 316–328, 1997 相似文献