全文获取类型
收费全文 | 290篇 |
免费 | 20篇 |
国内免费 | 1篇 |
专业分类
林业 | 12篇 |
农学 | 3篇 |
23篇 | |
综合类 | 11篇 |
农作物 | 16篇 |
水产渔业 | 57篇 |
畜牧兽医 | 135篇 |
园艺 | 1篇 |
植物保护 | 53篇 |
出版年
2022年 | 3篇 |
2021年 | 15篇 |
2020年 | 7篇 |
2019年 | 8篇 |
2018年 | 11篇 |
2017年 | 10篇 |
2016年 | 10篇 |
2015年 | 5篇 |
2014年 | 14篇 |
2013年 | 12篇 |
2012年 | 14篇 |
2011年 | 18篇 |
2010年 | 16篇 |
2009年 | 13篇 |
2008年 | 24篇 |
2007年 | 22篇 |
2006年 | 17篇 |
2005年 | 20篇 |
2004年 | 9篇 |
2003年 | 26篇 |
2002年 | 9篇 |
2001年 | 10篇 |
2000年 | 5篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1990年 | 1篇 |
1989年 | 1篇 |
排序方式: 共有311条查询结果,搜索用时 46 毫秒
251.
Kusakawa S Tohei A Jaroenporn S Watanabe G Taya K 《The Journal of reproduction and development》2007,53(3):545-554
Glutamate is the dominant excitatory neurotransmitter in a large number of physiological processes including neuroendocrine regulation. Some pharmacological studies have shown that different subtypes of glutamate receptor, such as the N-methyl-D-aspartic acid (NMDA) and alpha-amino-3-hydroxy-5-methy-4-isoxazolepropionic acid (AMPA) receptors, are involved in stress-induced adrenocorticotropin (ACTH) and prolactin secretion. However, the roles of the respective glutamate receptors and the mechanism of ACTH and prolactin secretion during stress via these receptors have not been investigated in detail. In the present study, we evaluated the role of AMPA-type glutamate receptor in ACTH and prolactin regulation under restraint stress in adult male rats. Male rats pretreated with a selective AMPA receptor antagonist, 2, 3-dihydroxy-6-nitro-7-sulfamoyl-benzo(f)quinoxaline (NBQX; 50 microg), through a lateral ventricle cannula were stressed by immobilization. Administration of NBQX inhibited ACTH and prolactin secretion in response to restraint stress. However, NBQX had no significant effects on the activity of tyrosine hydroxylase (TH), the rate-limiting enzyme in dopamine biosynthesis, as measured by the accumulation of 3, 4-dihydroxyphenylalanine (DOPA). In addition, administration of NBQX suppressed stress-induced prolactin secretion in the male rats pretreated with alpha-MT, an inhibitor of dopamine synthesis, and infused with dopamine solution (2.5 microg/200 microl/10 min). These results indicated that the effects of NBQX on prolactin secretion might be mediated by non-dopamine mechanisms. The contents of corticotropin-releasing hormone (CRH) and arginine vasopressin (AVP) in the median eminence (ME) of the male rats decreased during restraint stress; however, the fluctuations in CRH and AVP were eliminated by NBQX administration. These results suggest that stress-induced ACTH and prolactin release mediated by neurotransmission via AMPA receptors might be partly attributable to hypophysiotropic regulatory factors in the hypothalamus. 相似文献
252.
Kogi Ogawa Fuminari Ito Masaki Nagae Teiichi Nishimura Motoyoshi Yamaguchi Atsushi Ishimatsu 《Water, air, and soil pollution》2001,130(1-4):887-892
Changes in plasma cortisol, estoradiol-17β (E2) and 11-ketotestosterone (11-KT) levels under chronic acid exposure were examined to clarify the endocrinological effects of lowered environmental pH on gametogenesis in immature and gonadal developing carp, Cyprinus carpio. Plasma cortisol levels increased markedly 3 hours after the acid exposure and high levels were maintained for 48 hours, and then gradually decreased. Plasma E2 levels were significantly elevated and peaked at 1 week after the acid exposure. After that, E2 levels decreased gradually, but remained at significantly higher levels than the control group even at 4 weeks after the exposure. Plasma 11-KT levels showed no significant change throughout the experiment. These results indicate that acidic water disrupts the endocrine system that may have adverse effects on gametogenesis in freshwater fish. 相似文献
253.
Ohara Toshimasa Uno Itsushi Wakamatsu Shinji Murano Kentaro 《Water, air, and soil pollution》2001,130(1-4):295-300
Water, Air, &; Soil Pollution - During the spring, the high concentrations of ozone (O3) and aerosols are frequently observed aloft in Japan. Such episodes supposedly are caused by the... 相似文献
254.
Miloš Havelka He Zhou Seishi Hagihara Masaki Ichimura Takafumi Fujimoto Etsuro Yamaha Shinji Adachi Katsutoshi Arai 《Fisheries Science》2017,83(4):587-595
We investigated the source of spontaneous polyploidization in the critically endangered Acipenser mikadoi. Fourteen sib progeny of A. mikadoi and 11 hybrids between an A. mikadoi female and a Huso dauricus male, all showing atypically high ploidy, were analysed. Parent assignment based on five highly polymorphic microsatellite markers confirmed spontaneous duplication of maternal chromosome sets via retention of the second polar body to be the source of spontaneous polyploidization. To our knowledge, this provides the first evidence of the maternal origin of spontaneous polyploidization in A. mikadoi. Factorial correspondence analysis of the multilocus microsatellite genotypes placed the parent fish of spontaneous polyploids in clearly delineated clusters of A. mikadoi and H. dauricus, and parent fish had mitochondrial control region haplotypes corresponding to their presumed species. Thus, parent fish were confirmed to be of pure genetic origin, and hybridization did not promote the observed spontaneous polyploidization. 相似文献
255.
Satoshi KAMOTO Masahiro SHINADA Daiki KATO Masaya TSUBOI Sho YOSHIMOTO Ryohei YOSHITAKE Shotaro ETO Namiko IKEDA Yosuke TAKAHASHI Yuko HASHIMOTO James CHAMBERS Kazuyuki UCHIDA Shinji YAMADA Mika K. KANEKO Ryohei NISHIMURA Yukinari KATO Takayuki NAKAGAWA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2021,83(11):1795
Podoplanin is expressed in various human tumors where it promotes tumor progression, epithelial-mesenchymal transition, and distant metastasis. Podoplanin is also expressed in cancer-associated fibroblasts and induces tumor malignancy. The objective of this study was to evaluate podoplanin expression in various types of feline tumor tissues. Immunohistochemical analysis revealed that podoplanin was expressed in cells of 13/15 (87%) squamous cell carcinomas and 5/19 (26%) fibrosarcomas. Moreover, cancer-associated fibroblasts expressed podoplanin in most tumor types, including 18/21 (86%) mammary adenocarcinoma tissues. Our findings demonstrate that various types of feline tumor tissues expressed podoplanin, indicating the importance of the comparative aspects of podoplanin expression, which may be used as a novel research model for podoplanin biology. 相似文献
256.
Fisheries Science - A part of fishery waste, such as scallop or oyster shells, are utilized for fertilizer, feed, soil conditioner, or fishing ground preparations, and most of the shells from... 相似文献
257.
In recent studies, we found that Apll (a PthA homologue) bound to three citrus proteins. Amino acid sequence analysis revealed
that one of the target proteins was homologous to that of S-adenosyl-l-methionine : trans-caffeoyl-coenzyme A 3-O-methyltransferase (CCoAMT), an enzyme which is specific for the substrate trans-caffeoyl-CoA and catalyzes the synthesis of trans-feruloyl-CoA. From the consensus nucleotide sequences of CCoAMT genes, primers were chosen for PCR amplification of this
gene from citrus total DNA. Two selected DNA fragments of 1.0 kb and 2.0 kb were obtained. These fragments were used as the
probe to screen a citrus library. One clone, pCCl00, contained a 1.0-kb SalI fragment that hybridized to the probes. The nucleotide sequence of this fragment was determined in both directions. In this
fragment, there was an open reading frame of 232 amino acids interrupted by an intron of 106 nt, and the deduced amino acid
sequence had 95.9% homology to tobacco CCoAMT. Southern blot analysis of total citrus DNA showed that four EcoRI fragments hybridized to the probes, suggesting the presence of more than one copy of CCoAMT in the citrus DNA.
Received 4 November 1999/ Accepted in revised form 26 November 1999 相似文献
258.
259.
水稻有机栽培苗期恶苗病和立枯病防治技术的研究 总被引:1,自引:0,他引:1
水稻苗期恶苗病和立枯病是目前水稻有机栽培急需解决的苗期两大病害,目前国内还没有有效可行的解决办法,有关研究文献也很少。本研究在不使用农药、化肥及育苗调理剂条件下,利用物理方法(温汤处理)和有效微生物制剂(EM)进行防治苗期立枯病和恶苗病的试验。研究结果表明:①从种子发芽率、防治立枯病和恶苗病等因素综合考虑,采用温汤56℃处理10~15 min,58℃处理10 min较安全,即不影响发芽率又能达到防病效果;②EM活性液50~150倍液和EM稀释液500倍液具有促进秧苗的生长发育和防治立枯病的作用。 相似文献
260.
F. Ito T. Yamasaki M. Yamaguchi M. Nagae K. Soyano 《Fish physiology and biochemistry》2003,28(1-4):417-418
Results of the present study demonstrated that a specific combination of spawning substrate and water current was indispensable for the spawning of mature Japanese dace, Triborodon hakonensis. It became evident that the environmental factors acted as a trigger for endocrine changes leading to final maturation in this species. 相似文献