全文获取类型
收费全文 | 228篇 |
免费 | 20篇 |
专业分类
林业 | 21篇 |
农学 | 3篇 |
基础科学 | 1篇 |
23篇 | |
综合类 | 20篇 |
农作物 | 6篇 |
水产渔业 | 37篇 |
畜牧兽医 | 126篇 |
园艺 | 1篇 |
植物保护 | 10篇 |
出版年
2021年 | 4篇 |
2020年 | 4篇 |
2019年 | 2篇 |
2018年 | 2篇 |
2017年 | 6篇 |
2016年 | 10篇 |
2015年 | 8篇 |
2014年 | 7篇 |
2013年 | 13篇 |
2012年 | 15篇 |
2011年 | 17篇 |
2010年 | 7篇 |
2009年 | 4篇 |
2008年 | 17篇 |
2007年 | 13篇 |
2006年 | 14篇 |
2005年 | 12篇 |
2004年 | 14篇 |
2003年 | 10篇 |
2002年 | 6篇 |
2001年 | 13篇 |
2000年 | 12篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1992年 | 4篇 |
1991年 | 3篇 |
1990年 | 4篇 |
1989年 | 5篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 4篇 |
1981年 | 2篇 |
1972年 | 1篇 |
排序方式: 共有248条查询结果,搜索用时 31 毫秒
71.
Retrospectively, we demonstrated that seven pigs necropsied in 1989 had characteristic porcine circovirus 2 (PCV-2) lymphoid tissue lesions of severe lymphoid depletion, syncytial giant cell formation, and intracytoplasmic inclusion bodies in macrophages. Immunohistochemically, PCV-2 antigen was detected in these tissues and the distribution of positive staining corresponded to the distribution of inclusion bodies. Electron microscopy demonstrated viral particles compatible with porcine PCV-2. Therefore, the disease occurred in Japan as early as 1989. 相似文献
72.
Abanin DA Morozov SV Ponomarenko LA Gorbachev RV Mayorov AS Katsnelson MI Watanabe K Taniguchi T Novoselov KS Levitov LS Geim AK 《Science (New York, N.Y.)》2011,332(6027):328-330
Transport measurements have been a powerful tool for discovering electronic phenomena in graphene. We report nonlocal measurements performed in the Hall bar geometry with voltage probes far away from the classical path of charge flow. We observed a large nonlocal response near the Dirac point in fields as low as 0.1 tesla, which persisted up to room temperature. The nonlocality is consistent with the long-range flavor currents induced by the lifting of spin/valley degeneracy. The effect is expected to contribute strongly to all magnetotransport phenomena near the neutrality point. 相似文献
73.
K Yamasaki T Taga Y Hirata H Yawata Y Kawanishi B Seed T Taniguchi T Hirano T Kishimoto 《Science (New York, N.Y.)》1988,241(4867):825-828
Interleukin-6 (IL-6/BSF-2/IFN beta 2) is a multifunctional cytokine that regulates the growth and differentiation of various tissues, and is known particularly for its role in the immune response and acute phase reactions. A complementary DNA encoding the human IL-6 receptor (IL-6-R) has now been isolated. The IL-6-R consists of 468 amino acids, including a signal peptide of approximately 19 amino acids and a domain of approximately 90 amino acids that is similar to a domain in the immunoglobulin (Ig) superfamily. The cytoplasmic domain of approximately 82 amino acids lacks a tyrosine/kinase domain, unlike other growth factor receptors. 相似文献
74.
Harada Y Takagaki Y Sunagawa M Saito T Yamada L Taniguchi H Shoguchi E Sawada H 《Science (New York, N.Y.)》2008,320(5875):548-550
Hermaphroditic organisms avoid inbreeding by a system of self-incompatibility (SI). A primitive chordate (ascidian) Ciona intestinalis is an example of such an organism, but the molecular mechanism underlying its SI system is not known. Here, we show that the SI system is governed by two gene loci that act cooperatively. Each locus contains a tightly linked pair of polycystin 1-related receptor (s-Themis) and fibrinogen-like ligand (v-Themis) genes, the latter of which is located in the first intron of s-Themis but transcribed in the opposite direction. These genes may encode male- and female-side self-recognition molecules. The SI system of C. intestinalis has a similar framework to that of flowering plants but utilizing different molecules. 相似文献
75.
David Gamarra Noelia Aldai Aisaku Arakawa Marian M. de Pancorbo Masaaki Taniguchi 《Animal Science Journal》2021,92(1):e13521
Sterol regulatory element-binding factor 1 (SREBP1) plays an important role in the lipogenesis which affects fatty acid (FA) composition in backfat and consequently influences beef nutritional quality. This study analyzed the association of 84 bp-indel, both short (S) and long (L) alleles in intron 5 of SREBP1, with FA composition and gene expression of SREBP1 in backfat of northern Spanish beef breeds (Pirenaica, Salers and Holstein-Friesian). Phylogenetic analysis suggests that 84 bp-indel of ruminants is a highly conserved region compared with those in the full-length sequence of intron 5 or mRNA of SREBP1 among species. Overall, higher content of polyunsaturated FAs was observed in SL genotype compared to LL genotype of 84 bp-Indel (p < .05). In particular, in Pirenaica, SL genotype was associated with a higher content of stearic (18:0), α-linolenic (18:3n-3) acid, and total n-3 content (p < .05). However, the gene expression of SREBP1 did not differ among genotypes of 84 bp-Indel (p > .05). 相似文献
76.
Yoko Sato Ryota Kuriwaki Shiki Hagino Megumi Shimazaki Rentsenkhand Sambuu Maki Hirata Fuminori Tanihara Mitsuhiro Takagi Masayasu Taniguchi Takeshige Otoi 《Reproduction in domestic animals》2020,55(2):209-216
In Mongolia, yak (Bos grunniens) are able to live in alpine areas and their products greatly influence the lives of the local people. Increased vigour in hybridized yak and cattle can offer benefits for livestock farmers. However, male hybrids show reproductive defects resulting from spermatogenesis arrest, affecting the conservation and maintenance of dominant traits in the next generation. The underlying mechanisms involved in hybrid cattle–yak infertility have recently been investigated; however, the genetic cause is still unclear. Androgens and androgen receptor (AR) signalling are required for spermatogenesis. We, therefore, evaluated the expression of AR, 3β-hydroxysteroid dehydrogenase (3βHSD) and 5α-reductase 2 (SRD5A2) in Leydig cells to investigate their function in cattle–yak spermatogenesis. Testicular tissues from yaks (1–3 years old) and hybrids (F1–F3, 2 years old) were collected and subjected to immunohistochemistry and image analyses to investigate the expression of each parameter in the Leydig cells. After maturation at 2 years, the expression levels of AR increased and the levels of 3βHSD decreased, but the SRD5A2 levels remained constant in yak. However, the cattle–yak hybrid F2 showed immature testicular development and significantly different expression levels of AR and 3βHSD compared with mature yak. These results suggest that the decreased expression of AR and increased expression of 3βHSD in the Leydig cells of cattle–yak hybrid testes may represent one of the causes of infertility. Our study might help in solving the problem of infertility in crossbreeding. 相似文献
77.
Shinya Ishihara Fukuhiro Yamasaki Pham Hai Ninh Nguyen Cong Dinh Aisaku Arakawa Masaaki Taniguchi Ngo Thi Kim Cuc Satoshi Mikawa Masaru Takeya Kazuhiro Kikuchi 《Animal Science Journal》2020,91(1)
Although there are a number of Vietnamese native pig (VnP) populations, some are on the verge of extinction, and therefore adequate management and conservation are necessary. In this study, we conducted a field survey of VnP populations and analyzed interrelationships among their characteristics. We also established a relational database for management of field data on these populations. For data collection, we conducted interviews with farmers and visual inspection of 32 VnP populations in 22 provinces of Vietnam, as well as taking photographs of individual animals. Data on the characteristics of VnP populations were subjected to multiple correspondence analysis (MCA). For establishment of the database, normalization and table partitioning were performed to eliminate redundancy and ensure consistency of the collected data items. Passport data, characteristics data, and image data were collected from a total of 1,918 VnPs and entered as a normalized table. Upon MCA, most of the populations were not separated from each other, but the Mong Cai, O Lam, and Chu Prong populations were separated from the other populations. Thus, we have constructed a relational database from comprehensive information on the characteristics of VnP populations. 相似文献
78.
79.
Yukio?AgatsumaEmail author Yasuhiro?Kuwahara Kazuya?Taniguchi 《Fisheries Science》2005,71(5):1107-1114
ABSTRACT: The life cycle of Dilophus okamurae and the associated benthic invertebrate fauna were studied monthly or bimonthly from June 1998 to September 1999 at a depth of 4–7 m in Onagawa Bay along the Pacific coast of north-eastern Honshu, Japan (38°28'N, 149°29'E). Dry biomass ranged from 230 g/m2 in June to 10 g/m2 in October. Sporophytes with tetrasporangia appeared during July to September 1998. Gametophytes with oogonia or antheridia were observed for the first time in May 1999 during observation. The absence of mature sporophytes in 1999 suggests that the life cycle is completed over two years. The sympatric gastropods Lirularia iridescens , Homalopoma sangrarense, Conotalopia minima and Cantharidus callichroa synchronized with seasonal changes in biomass of this algae. In contrast, Barleeia angustata and B. trifasciata fluctuated independently. The juvenile sea urchin Strongylocentrotus nudus appeared in the algal population starting in October at 0.7 mm mean test diameter at high density, and disappeared after March. 相似文献
80.
Thawatchai Ngamsiri Masamichi Nakajima Srijanya Sukmanomon Naruepon Sukumasavin Wongphatom Kamonrat Uthairat Na-Nakorn Nobuhiko Taniguchi 《Fisheries Science》2007,73(4):792-799
The Mekong giant catfish Pangasianodon gigas is endemic to the Mekong River and is a critically endangered species. The genotypes of the microsatellite DNA (msDNA) and
mitochondrial DNA (mtDNA) markers (right domain of the control region) were detected to evaluate the present status of genetic
divergence of this species from the Mekong River in Thailand and Cambodia. The observed and expected heterozygosity values
of Mekong giant catfish in Thailand and Cambodia were relatively low in comparison with those of other nonendangered freshwater
fish species. These two populations from Thailand and Cambodia showed similar levels of genetic diversity, as evaluated by
the 384 nucleotides of the mtDNA control region with 13 haplotypes. The pairwise F
ST value between the two populations based on the genotype frequencies of msDNA and mtDNA markers suggested a close genetic
relationship between the populations in Thailand and Cambodia. The results of this study support the conclusion that the Mekong
giant catfish is critically endangered. Care should be taken to sustain the genetic diversity of this species, as the level
of genetic variability has already decreased in the wild population. This species is a target species for an ongoing stock
enhancement program in the Mekong River in Thailand. It is proposed to apply these markers for proper broodstock management,
such as for minimal kinship selective breeding in the hatchery. 相似文献