首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   349篇
  免费   7篇
  国内免费   1篇
林业   48篇
农学   5篇
  25篇
综合类   14篇
农作物   25篇
水产渔业   38篇
畜牧兽医   151篇
园艺   3篇
植物保护   48篇
  2022年   3篇
  2021年   25篇
  2020年   4篇
  2019年   3篇
  2018年   10篇
  2017年   4篇
  2016年   7篇
  2015年   35篇
  2014年   21篇
  2013年   25篇
  2012年   18篇
  2011年   29篇
  2010年   19篇
  2009年   22篇
  2008年   21篇
  2007年   16篇
  2006年   19篇
  2005年   11篇
  2004年   16篇
  2003年   11篇
  2002年   14篇
  2001年   8篇
  2000年   6篇
  1998年   3篇
  1997年   1篇
  1996年   1篇
  1993年   2篇
  1988年   1篇
  1966年   1篇
  1953年   1篇
排序方式: 共有357条查询结果,搜索用时 15 毫秒
1.
2.
A questionnaire study examining Japanese consumers’ requirements for beef quality was carried out in April 2002 in Tsukuba, Ibaraki, Japan. Answers from 532 participants were used for the statistical analysis. Twenty questions about sensory properties, appearance, safety and freshness, production area, price, and other properties were prepared. The answers were applied to principal component analysis. Five principal components were obtained and defined, and the principle component scores were used to classify participants. The panels were classified into four groups profiled as ‘specific quality orientated’, ‘Wagyu (Japanese beef) orientated’, ‘safety and freshness orientated’ and ‘overall high quality orientated’. In addition, gender and age characteristics were different among the groups. Sensory properties did not affect the classification of respondents.  相似文献   
3.
In order to determine the role of the cecum on energy use in growing chickens, metabolizability of the dietary energy and energy expenditure were examined in the week following bilateral ligation and washing out of the cecum. Apparent metabolizable energy (AME) values were 14.30 and 13.69 kJ/g air‐dry matter for sham‐operated and cecally ligated chickens, respectively. These values were found to be significantly different (P < 0.05). Although AME intake and fasting heat production were decreased by cecal ligation, the distribution of AME (measured as fasting and feeding heat production, as well as heat increment and energy retention, as a proportion of AME intake) was not affected. These results suggest that the cecum helps chickens extract AME from corn‐soybean type diets with little, if any, effect on AME use, based on the present study of growing chickens in the week following cecal ligation.  相似文献   
4.
The effect of insulin on the ascorbate recycling system in the chicken liver was examined. First, insulin was injected subcutaneously into the chicken, and liver glutathione‐dependent dehydroascorbate reductase (GSH‐DHAR) activity was determined. Insulin increased liver GSH‐DHAR activity, but did not affect plasma and liver ascorbate concentration. Dehydroascorbate increased plasma and liver ascorbate levels, and liver GSH‐DHAR activity. However, distinct changes in plasma insulin level were not observed by dehydroascorbate injection. In addition, reduction of external dehydroascorbate in cultured chicken hepatocytes could not be observed in an insulin‐deprived culture, although the cells reduced external dehydroascorbate in a serum‐free culture with insulin. We concluded that insulin affects the ascorbate recycling system as an essential factor in the chicken liver.  相似文献   
5.
We examined the antimicrobial susceptibility of 848 Escherichia coli isolates from 237 feces samples of wild sika deer (Cervus nippon) captured between 2016 and 2019 in 39 of the 47 prefectures of Japan. Five of the 237 wild sika deer (2.1%) carried E. coli with resistance to at least one antimicrobial, and all the resistant isolates showed resistance to tetracycline. The resistant isolates contained antimicrobial resistance genes that were similar to those in E. coli derived from humans and farm animals. Although wild sika deer are not currently likely to be a source for the transmission of antimicrobial resistance in Japan, they can potentially mediate antimicrobial resistance spread by coming into contact with humans, animals, and their surroundings.  相似文献   
6.
MX belongs to a family of type I interferon (IFN)-stimulated genes, and the MX protein has antiviral activity. MX has at least two isoforms, known as MX1 and MX2, in mammals. Moreover, bovine MX1 has been found to have alternative splice variants—namely, MX1-a and MX1B. In ruminants, IFN-τ—a type I IFN—is temporarily produced from the conceptus before implantation and induces MX expression in the endometrium. However, the expression dynamics of MX after implantation are not clear. In the present study, we investigated the expression of MX1-a, MX1B and MX2 in the endometrium and placenta before and after implantation along with the expression of IFN-α, type I receptors (IFNAR1 and IFNAR2) and interferon regulatory factors (IRF3 and IRF9). Pregnant uterine samples were divided into five groups according to pregnancy days 14–18, 25–40, 50–70, 80–100, and 130–150. Tissue samples were collected from the intercaruncular endometrium (IC), caruncular endometrium (C) and fetal placenta (P). Although all the MX expressions were significantly higher in the IC and C at days 14–18, presumably caused by embryo-secreted IFN-τ stimulation, their expressions were also detectable in the IC, C and P after implantation. Furthermore, IFN-α expression was significantly higher in the IC. RT-PCR indicated IFNAR1, IFNAR2, IRF3 and IRF9 mRNA in all the tissues during pregnancy. These results suggest that all the MX genes are affected by the type I IFN pathway during pregnancy and are involved in an immune response to protect the mother and fetus.  相似文献   
7.
8.
Perchloric acid-soluble protein (PSP) is a members of a new hypothetical family (YER057c/YJGF family) of small proteins with presently unknown function. The high degree of evolutionary conservation of these proteins reflect an involvement in basic cellular regulation. The expression of PSP was examined in rat hepatoma cell dRLh 84-beared rats. The tumor weight increased to 4.24 g at 3 weeks after the transplantation of hepatoma cells and hepatoma which has less differentiated characteristics were observed in rat liver. The expression of PSP in rat hepatoma was down regulated as compared with intact tissue. Thus the expression of PSP seems to be associated with the differentiation process in these transformed cells. On the other hand, some positive cells against the PSP-antibody were observed in the central region of tumor tissue by immunohistochemistry. These cells were shown to be the lymphocytes and the macrophages. The involvement of PSP to cellular growth and differentiation is discussed.  相似文献   
9.
The purpose of the present paper was to investigate the effect of regular walking exercise on glucose tolerance and insulin response to i.v. glucose infusion in growing beef steers. Four crossbred beef steers walked on a treadmill during a 6 week exercise period (1.2 km/h, 1 h/day and 5 days/week). The changes in plasma glucose and insulin levels following glucose infusion were analyzed immediately prior to (bodyweight: 260.4 ± 24.2 kg) and after (295.7 ± 30.1 kg) the exercise period. The basal levels of plasma glucose (86.4 vs. 82.0 mg/dL, P = 0.040) and insulin (24.5 vs. 14.3 μU/mL, P = 0.016) were significantly lower after the exercise period. Further, the increase in the levels of plasma glucose (420.4 vs. 280.8 mg/dL, P < 0.001) and insulin (94.5 vs. 73.1 μU/mL, P = 0.028) following the glucose infusion decreased after the exercise period. The area under the curve of plasma glucose (108.8 vs. 62.9 mg/dL per min, P < 0.001) and insulin (53.6 vs. 29.7 μU/mL per min, P = 0.018) indicated more rapid clearance of exogenous glucose and less insulin secretion for glucose clearance after the exercise period. These results suggest that regular exercise improves glucose tolerance, with lower insulin response to glucose infusion in growing steers, as observed in rodents and humans.  相似文献   
10.
We have shown in vitro that mechanical stretch triggers activation of quiescent satellite cells of skeletal muscle to enter the cell cycle through an intracellular cascade of events including nitric oxide (NO) synthesis that results in the release of hepatocyte growth factor (HGF) from its extracellular association and its subsequent presentation to signaling receptors. In order to explore the activation mechanism in vivo, stretch experiments were conducted in the living animal using our suspension model developed. This system used the weight of the hind portion of rats to stretch the inside muscles of the left hind limb suspended for a period of 0.5–2.0 h. At the end of the stretch period, the rats received an intraperitoneal injection of bromodeoxyuridine followed by immunocytochemistry for its incorporation as an index of satellite cell activation in vivo. Depending on the period of stretch, bromodeoxyuridine labeling was increased significantly over the contralateral unstretched leg or control muscle from untreated rats. A stretched muscle extract prepared from the 2 h stretched tissue by incubating it in PBS, showed the active form of HGF as revealed by immunoblotting and it could stimulate the activation of unstretched satellite cells. Also, administering NO synthase inhibitor L‐NAME prior to muscle stretch abolished the stretch activation of satellite cells. Therefore, the results from these experiments demonstrate that stretching muscle triggers NO synthesis and HGF release, which could activate satellite cells in vivo.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号