全文获取类型
收费全文 | 1471篇 |
免费 | 54篇 |
国内免费 | 1篇 |
专业分类
林业 | 185篇 |
农学 | 73篇 |
295篇 | |
综合类 | 74篇 |
农作物 | 65篇 |
水产渔业 | 142篇 |
畜牧兽医 | 563篇 |
园艺 | 10篇 |
植物保护 | 119篇 |
出版年
2023年 | 4篇 |
2022年 | 22篇 |
2021年 | 32篇 |
2020年 | 26篇 |
2019年 | 19篇 |
2018年 | 25篇 |
2017年 | 29篇 |
2016年 | 44篇 |
2015年 | 50篇 |
2014年 | 57篇 |
2013年 | 162篇 |
2012年 | 82篇 |
2011年 | 107篇 |
2010年 | 50篇 |
2009年 | 65篇 |
2008年 | 93篇 |
2007年 | 81篇 |
2006年 | 106篇 |
2005年 | 91篇 |
2004年 | 82篇 |
2003年 | 73篇 |
2002年 | 49篇 |
2001年 | 31篇 |
2000年 | 27篇 |
1999年 | 20篇 |
1998年 | 16篇 |
1997年 | 4篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 3篇 |
1991年 | 9篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1988年 | 5篇 |
1987年 | 4篇 |
1986年 | 10篇 |
1985年 | 7篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1971年 | 1篇 |
1970年 | 3篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1967年 | 3篇 |
1966年 | 1篇 |
1964年 | 2篇 |
1962年 | 1篇 |
排序方式: 共有1526条查询结果,搜索用时 531 毫秒
991.
Mochizuki H Takahashi M Nishigaki K Ide T Goto-Koshino Y Watanabe S Sato H Sato M Kotera Y Fujino Y Ohno K Uchida K Tsujimoto H 《Veterinary immunology and immunopathology》2011,141(3-4):307-311
There is significant lack of basic hematologic and immunological data in adult sows. Therefore, aim of this study was to provide respective reference intervals. 32 clinically healthy multiparous Large White sows aged 33.5 ± 9.6 months and all of them two months postpartum were included in this study. Mean erythrocyte count was 5.5 ± 0.7 × 10(6)/μl and total leukocyte count was 12.1 ± 2.1 × 10(3)/μl. Proportion of lymphocytes was 44.7 ± 10.2% and of neutrophils 41.6 ± 11.0%. The ratio of na?ve T helper (Th) cells to memory Th cells was 1:3.1 and the ratio of Th cells to cytotoxic T cells (CTLs) was 1:4.2. Proportions of regulatory T cells, NK cells, and CD21(+) B cells were lower (3.1, 2.6, and 6.0%) than those of memory Th cells ranging from 8.8 to 27.5% depending on the activation status and CTLs with 37.3%. γδ T cells were found at comparably high numbers (19.1%). Flow cytometric measurement of intracellular cytokines in PBMCs revealed marginal levels for IL-1β, IL-2, IL-4, IL-6, IL-10, and IL-12p35, but remarkable levels for TNF-α and IFN-γ. Highest mRNA levels were found for IL-1, IL-10, and TNF-α, with TNF-α showing the least inter-individual variation. 相似文献
992.
Hiroyuki NAKAYAMA Tetsuya TAKAHASHI Kaori NAKAGAWA‐MIZUYACHI Mitsuo KAWASHIMA 《Animal Science Journal》2011,82(5):679-683
The equilibrium dissociation constant (Kd) and the maximum binding capacity (Bmax) of calcitonin (CT) receptor in the plasma membrane of the anterior pituitary in hens were examined by Scatchard analysis of specific binding of 125I‐labeled chicken CT. Values of Kd and Bmax of CT receptor were smaller in laying hens than in non‐laying hens. A decrease in the Kd and Bmax value of CT receptor was observed in the anterior pituitary after the injection of estradiol‐17β and progesterone into nonlaying hens, but not changed after the injection of 5α‐dihydrotestosterone. During an oviposition cycle, the Kd and the Bmax value decreased 3 h before oviposition. In non‐laying hens, neither the Kd nor the Bmax value changed during a full day period. The present study suggests that the CT action on the anterior pituitary may increase 3 h before oviposition by the effect of estradiol‐17β and progesterone in laying hens. 相似文献
993.
Kazuhiro KIKUCHI Michiko NAKAI Naomi KASHIWAZAKI Hiroyuki KANEKO 《Animal Science Journal》2011,82(4):495-503
In vitro production of embryos, including in vitro maturation, fertilization of oocytes and their subsequent culture to the embryo stage, has become the most popular method of studying gametogenesis and embryogenesis in pigs. As well as their utility for basic studies, these procedures now enable us to generate viable embryos and offspring as a means of conserving genetic resources and rare animal breeds. Recently, more advanced technologies such as xenografting of gonadal (testicular and ovarian) tissues into immunodeficient experimental animals have been developed. In combination with in vitro embryo production techniques, this approach may provide many benefits. We have been carrying out studies to acquire basic information about the application of this method to porcine species, and to improve the existing techniques. Recently, we obtained oocytes from ovarian tissue xenografted and grown in nude mice that had the capacity to be fertilized and the ability to develop into early‐stage embryos. We also obtained spermatozoa from the xenografted testicular tissues and injected them intracytoplasmically into in vitro‐matured oocytes to produce piglets. Here we discuss the further possibilities of conservation and utilization of porcine gonadal tissue by xenografting into immunodeficient mice. 相似文献
994.
Yang CAO Yimin CAI Tomomi HIRAKUBO Hiroyuki FUKUI Hiroki MATSUYAMA 《Animal Science Journal》2011,82(2):259-266
Total mixed ration (TMR) silage in different seasons was prepared with apple refuse, orchardgrass hay, orchardgrass silage, corn silage and a commercial compound feed in Tohoku, Japan, and with tofu cake, brewers' grains, tall fescue hay, Sudangrass hay, timothy hay, alfalfa hay and a commercial compound feed in Shikoku, Japan, respectively, and their fermentation quality and microorganism composition were evaluated. In Tohoku, the TMR silage in spring, autumn and winter displayed poor quality, with pH value above 4.7, and the harmful microorganisms such as escherichia, yeasts and molds were detected even after 60 days of ensiling; but the TMR silage in summer was well preserved and the escherichia were too few to count after 7 days of ensiling. In Shikoku, the TMR silage in all seasons was well preserved, with low pH, high lactic acid contents, and escherichia, yeasts and molds were consistently at or below the detectable numbers after 7 days of ensiling. The results showed that the TMR silage could not produce sufficient lactic acid to improve silage quality under low‐temperature conditions. Therefore, it is necessary to develop preparation techniques of promoting the lactic acid fermentation for TMR silage in cold seasons. 相似文献
995.
Body weight and fatness are quantitative traits of agricultural and medical importance. In previous genome‐wide quantitative trait locus (QTL) analyses, two QTLs for body weight and weight gain at an early postnatal growth period were discovered on mouse chromosome 10 from a gene pool of wild subspecies mice, Mus musculus castaneus. In this study, we developed a congenic strain with an approximately 63‐Mb wild‐derived genomic region on which the two growth QTLs could be located, by recurrent backcrossing to the common inbred strain C57BL/6J. We compared body weights at 1–10 weeks of age, body weight gains at 1–3, 3–6 and 6–10 weeks, internal organ weights and body lengths between the congenic strain developed and C57BL/6J. Unfortunately, no effects of the two growth QTLs on body weights and weight gains were confirmed. However, at least two new QTLs affecting fatness traits were discovered within the introgressed congenic region. The wild‐derived allele at one QTL increased body mass index, whereas at another one it decreased white fat pad weight and adiposity index. Thus, the congenic mouse strain developed here is a useful model animal for understanding the genetic and molecular basis of fat deposition in livestock as well as humans. 相似文献
996.
Pramod DHAKAL Nobuo TSUNODA Rie NAKAI Tomoki KITAURA Takehiro HARADA Masahiro ITO Kentaro NAGAOKA Yuko TOISHI Hiroyuki TANIYAMA Watanabe GEN Kazuyoshi TAYA 《Journal of Equine Science》2011,22(2):29-36
Changes in follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin,
immunoreactive(ir)-inhibin, testosterone, estradiol-17β, and insulin-like growth factor
(IGF)-I in Thoroughbred stallions along with changes in prolactin secretion in geldings
were studied. The correlations of day-length with changes in the concentrations of these
hormones were also studied. Five stallions and thirteen geldings were employed to draw
blood samples in monthly basis and radioimmunoassay was performed to measure these
hormones. All hormones showed a seasonal pattern, the levels being highest during the
breeding season and lowest during the winter months. Most of the hormones were at their
highest concentration during the month of April, the mid of spring in northern hemisphere.
The concentration of circulating IGF-I also demonstrated seasonality, the peak lying on
the month of April. The plasma concentration of prolactin also increased during the
breeding season. This phenomenon was similar both in stallions and geldings although
geldings had lower concentration than that of stallions. The changes in concentration of
prolactin in stallions and geldings correlated more towards the day-length than towards
the temperature. These results clearly indicate the seasonality of pituitary and gonadal
hormones of Thoroughbred stallions, the activity being highest during the month of April
and May of the breeding season. 相似文献
997.
Pramod DHAKAL Nobuo TSUNODA Rie NAKAI Kentaro NAGAOKA Yasuo NAMBO Fumio SATO Hiroyuki TANIYAMA Watanabe Kazuyoshi TAYA 《Journal of Equine Science》2011,22(1):9-15
The aim of present study was to clarify the post-natal profile of follicle-stimulating
hormone (FSH), luteinizing hormone (LH), immunoreactive (ir)-inhibin, progesterone,
testosterone, and estradiol-17β, and their relationships in Thoroughbred colts. Six
hundred and thirty-six colts were used for the study. Single plasma samples from each
animal were harvested from the blood drawn through jugular venipuncture. The subjects were
born with high amounts of progesterone, testosterone, and estradiol-17β, all of which
dropped significantly and remained at lower levels till the end of 6 months. FSH decreased
transiently after birth until day 12 and then gradually increased to peak at day 100 which
then maintained in lesser levels towards the end of the studied period. LH was highest
during birth which decreased until day 26 and then increased slowly to sub-birth levels up
to day 90. Animals were born with high amounts of ir-inhibin. It dropped slowly and halved
by day 20 and then decreased towards rest of the studied period. The increase in FSH is
negatively correlated with the declining ir-inhibin levels. The early increase in FSH can
be the indication of early post-natal maturation of the hypothalamic pituitary testicular
axis that ultimately might be responsible for priming the testes for future
development. 相似文献
998.
999.
小麦新种质YW243抗条锈病新基因对条锈菌具有较宽抗谱,对26个不同毒性谱的条锈菌 菌系免疫到近免疫,与已知基因系抗病谱不同,可能为新的基因或基因组合。遗传分析表明,YW243 对条锈菌条中31号小种的抗性由显性单基因YrX控制。通过BSA法对1056对MseI/EcoRI AFLP引 物进行筛选,结果表明7对引物可扩增出多态性片段,通过对F2群体单株遗传连锁分析和作图软件 分析,结果表明,2个AFLP标记M54E63-700、M54E64-699与YrX连锁较紧密、遗传距离为9.27 cM,为该基因的精细作图和分子标记辅助育种打下了一定基础。 相似文献
1000.
Stamatoyannopoulos G Yoshida A Adamson J Heinenberg S 《Science (New York, N.Y.)》1968,159(3816):741-743
Hemoglobin Rainier, a new hemoglobin variant associated with erythrocytosis, was found in six members of a Caucasiant family. Structurally, it represents substitution of histidine for the invariant residute H23 tyrosine in the beta-hemoglobin polypeptide chain (beta(145) tyrosine --> histidine). Hemoglobin Rainier is the first example of a single amino acid substitution in adult human hemoglobin, causing increased resistance to alkali denaturation. 相似文献