全文获取类型
收费全文 | 1730篇 |
免费 | 138篇 |
国内免费 | 1篇 |
出版年
2023年 | 6篇 |
2022年 | 18篇 |
2021年 | 25篇 |
2020年 | 19篇 |
2019年 | 12篇 |
2018年 | 19篇 |
2017年 | 19篇 |
2016年 | 37篇 |
2015年 | 45篇 |
2014年 | 53篇 |
2013年 | 112篇 |
2012年 | 84篇 |
2011年 | 102篇 |
2010年 | 68篇 |
2009年 | 60篇 |
2008年 | 114篇 |
2007年 | 96篇 |
2006年 | 102篇 |
2005年 | 103篇 |
2004年 | 117篇 |
2003年 | 91篇 |
2002年 | 90篇 |
2001年 | 35篇 |
2000年 | 47篇 |
1999年 | 32篇 |
1998年 | 19篇 |
1997年 | 15篇 |
1996年 | 16篇 |
1995年 | 13篇 |
1994年 | 10篇 |
1993年 | 13篇 |
1992年 | 32篇 |
1991年 | 24篇 |
1990年 | 17篇 |
1989年 | 30篇 |
1988年 | 29篇 |
1987年 | 19篇 |
1986年 | 22篇 |
1985年 | 17篇 |
1984年 | 10篇 |
1983年 | 10篇 |
1982年 | 11篇 |
1981年 | 11篇 |
1980年 | 8篇 |
1979年 | 8篇 |
1978年 | 4篇 |
1977年 | 4篇 |
1976年 | 3篇 |
1974年 | 5篇 |
1967年 | 3篇 |
排序方式: 共有1869条查询结果,搜索用时 93 毫秒
71.
72.
Evidence has been presented showing two kinds of acidic protease activities in adult Schistosoma mansoni, Dirofilaria immitis, Angiostrongylus cantonensis and Ascaris suum. A haemoglobinolytic activity without adding any SH-containing compounds was maximal at pH 3.5, 2.5, 3.0 and 3.5 in S. mansoni, D. immitis, Angiostrongylus cantonensis and Ascaris suum respectively. The inhibitor studies demonstrated that this activity is ascribable to carboxyl protease(s). In the presence of dithiothreitol, activity on Azocoll (azo-dye coupled hide powder) was maximal at pH 4.6, 4.6, 3.5 and 5.6 in S. mansoni, D. immitis, Angiostrongylus cantonensis and Ascaris suum respectively. The effects of inhibitors demonstrated that this activity belongs to the thiol protease class. The intraspecific distribution of the protease activities was studied in some of the nematodes from which the organs could be anatomically separated. The distribution patterns of the haemoglobinolytic and azocollytic activities were quite different in An. cantonensis and much the same in As. suum. Based on the present results, acidic haemoglobinolytic activities reported in adult S. mansoni by other authors are thought to be due to carboxyl and thiol protease(s) respectively. 相似文献
73.
Nobuo Kitada Ryohei Saito Rika Obata Satoshi Iwano Kazuma Karube Atsushi Miyawaki Takashi Hirano Shojiro A. Maki 《Chirality》2020,32(7):922-931
Interestingly, only the D-form of firefly luciferin produces light by luciferin–luciferase (L–L) reaction. Certain firefly luciferin analogues with modified structures maintain bioluminescence (BL) activity; however, all L-form luciferin analogues show no BL activity. To this date, our group has developed luciferin analogues with moderate BL activity that produce light of various wavelengths. For in vivo bioluminescence imaging, one of the important factors for detection sensitivity is tissue permeability of the number of photons emitted by L–L reaction, and the wavelengths of light in the near-infrared (NIR) range (700–900 nm) are most appropriate for the purpose. Some NIR luciferin analogues by us had performance for in vivo experiments to make it possible to detect photons from deep target tissues in mice with high sensitivity, whereas only a few of them can produce NIR light by the L–L reactions with wild-type luciferase and/or mutant luciferase. Based on the structure–activity relationships, we designed and synthesized here a luciferin analogue with the 5-allyl-6-dimethylamino-2-naphthylethenyl moiety. This analogue exhibited NIR BL emissions with wild-type luciferase (λmax = 705 nm) and mutant luciferase AlaLuc (λmax = 655 nm). 相似文献
74.
75.
Matsumoto Yuuki Kaneita Yoshitaka Jike Maki Osaki Yoneatsu Kanda Hideyuki Higuchi Susumu Itani Osamu Otsuka Yuichiro 《Sleep and biological rhythms》2021,19(3):325-336
Sleep and Biological Rhythms - This study aimed to assess the success of the Japanese government’s “Early to bed, early to rise, and don’t forget your breakfast” (EB, ER,... 相似文献
76.
Maki Ohtani Jun-ichi Hikima Tae-Sung Jung Hidehiro Kondo Ikuo Hirono Haruko Takeyama Takashi Aoki 《Fish & shellfish immunology》2013,34(2):724-728
Phage display libraries are used to screen for nucleotide sequences that encode immunoglobulin variable (V) regions that are specific for a target antigen. We previously constructed an immunoglobulin new antigen receptor (IgNAR) phage display library. Here we used this library to obtain an IgNAR V region that is specific for viral hemorrhagic septicemia virus (VHSV). A phage clone (clone 653) was found to be specific for VHSV by the biopanning method. The V region of clone 653 was used to construct a 6 × His tagged recombinant IgNAR-653 V protein (rIgNAR-653) using the Escherichia coli pET system. The rIgNAR-653 protein bound specifically to VHSV, confirming its activity. 相似文献
77.
78.
Kazuki Miyaji Maki Kato Nobuyo Ohtani Mitsuaki Ohta 《Journal of applied animal welfare science : JAAWS》2013,16(4):355-362
The objective of this study was to evaluate the effects of diet on the feline stress response by measuring plasma and urinary cortisol. A study diet was developed with a unique combination of nutrients that supports the management of stressful situations. The specific formulation of the diet included alpha-casozepine, which is believed to have an anxiolytic effect, and tryptophan supplementation. Tryptophan is the precursor for the synthesis of the neurotransmitter serotonin. Twenty-one indoor cats were fed with the study diet (n = 10) or a control diet (n = 11) for 8 weeks, after which physiological responses were evaluated. The study diet significantly increased the ratio of plasma tryptophan to large neutral amino acids and decreased urinary cortisol concentrations after being consumed daily for 8 weeks, but there was no effect on plasma cortisol levels following a stressful event (veterinary examination and blood draw). Further studies, such as behavioral analyses, are needed to clarify the effects of the study diet. 相似文献
79.
Maki Sugaya Futoshi Nishimura Akira Katoh Kazuo Harada 《Nucleosides, nucleotides & nucleic acids》2013,32(5):534-545
In this study, the ability to tailor the peptide-binding specificity of an RNA was investigated. First, variants of the Rev-response element (RRE) RNA with different specificities toward the natural binding partner, Rev, and two RRE-binding aptamers, the RSG-1.2 and the Kl peptides, were identified. Next, hybrid RRE mutants with combinations of two sets of specificity-altering substitutions were tested for peptide-binding specificity. It was shown that in most cases the results of the combination of individual mutations were of an additive nature, therefore providing a way to manipulate the peptide-binding specificity of an RNA in a predictable manner. 相似文献
80.
Atsuko Miyagi Maki Kawai-Yamada Minori Uchimiya Noriyuki Ojima Koichi Suzuki Hirofumi Uchimiya 《Metabolomics : Official journal of the Metabolomic Society》2013,9(6):1254-1261
Evolution has shown the co-dependency between host plants and predators (insects), especially inevitable dependency of predators on plant biomass for securing their energy sources. It was postulated that NAD+ source used for major energy producing pathway is the glycerol-3-phosphate shuttle in insects. Using high throughput metabolomics approach, we found that larva of leaf beetle (Gastrophysa atrocyanea), which feed oxalate-rich plants (Rumex obtusifolius), possessed a unique mechanism for accumulating unusually high amounts of lactate. Similarly, larva of butterfly (Papilio machaon) fed with fennel (Foeniculum vulgare) accumulated lactate. Same butterfly also showed the elevated level of glycerol-3-phosphate equivalent to lactate. These evidences provide new insights into the mechanism underlying metabolite alteration between host plants and insect herbivores. 相似文献