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   262篇
  免费   10篇
林业   17篇
农学   3篇
  61篇
综合类   8篇
农作物   8篇
水产渔业   38篇
畜牧兽医   120篇
园艺   1篇
植物保护   16篇
  2022年   3篇
  2021年   14篇
  2020年   2篇
  2019年   2篇
  2018年   3篇
  2017年   4篇
  2016年   12篇
  2015年   9篇
  2014年   13篇
  2013年   31篇
  2012年   12篇
  2011年   14篇
  2010年   10篇
  2009年   8篇
  2008年   23篇
  2007年   27篇
  2006年   21篇
  2005年   16篇
  2004年   12篇
  2003年   14篇
  2002年   9篇
  2001年   1篇
  2000年   5篇
  1995年   1篇
  1993年   1篇
  1991年   1篇
  1988年   1篇
  1987年   1篇
  1950年   2篇
排序方式: 共有272条查询结果,搜索用时 125 毫秒
91.
Fish Physiology and Biochemistry - To reveal direct effects of various protein sources on digestive physiology of red seabream, Pagrus major (38.5 ± 0.4 g), six different...  相似文献   
92.
93.
94.
95.
Most global climate change models predict serious ecological and social problems. In Japan, biologists have found climate change is affecting species and ecosystems, including the earlier flowering time of cherry trees which are an important cultural symbol in Japan. Cherry blossom festivals are also important to local economies. This study explored the perceptions of Japanese residents regarding climate change impacts on culturally significant events such as flower timing of cherry trees. We conducted interviews of stakeholders of three cherry blossom festivals, including sixteen organizers of festivals and 26 managers of festival-dependent businesses, to understand their awareness, attitudes and behaviors toward global climate change and impacts on cherry blossom festivals. Most organizers of the festival in Kakunodate were concerned about global warming and its impact on cherry blossom times while organizers of festivals in Nakano and Komoro felt it was unimportant if flower timing affected the festival schedule. Most (92%) managers of festival-dependent businesses mentioned that global warming is occurring and affecting the flower timing of cherry trees, but there were diverse perceptions of global warming impacts on their business. Managers more dependent on income from cherry blossom festivals indicated greater concern for the effects of climate change.  相似文献   
96.
The DNA microarray analysis for matrix metalloproteinase (MMP)-related mRNA expression in equine superficial digital flexor tendinitis indicated that mRNA level of MMP-13 was apparently up-regulated in the tendinitis as compared to normal tendon. In situ hybridization also revealed that fibroblastic cells proliferated in the granulation tissue generated in the tendinitis actively expressed MMP-13 mRNA. On the other hand, in normal tendon, a few fibroblastic cells and vascular components lied in the endotenon barely expressed its mRNA, but other cellular components in the tendon bundle were not positively hybridized. As mentioned above, MMP-13 but not other collagenases or gelatinases, may play an important role in tendon injuries in the racehorses.  相似文献   
97.
To evaluate the effects of a new synbiotic consisting of Lactobacillus casei subsp. casei (Lcc) and dextran (Dex) on milk production, a total of 58 Holstein dairy cows, which became pregnant and gave birth to calves at regular intervals and lactated steadily and continuously, were selected. The study had a completely randomized design, and the animals were divided into two groups. Group A was fed with a basic diet only, and Group B was fed with a basic diet supplemented with the synbiotic consisting of freeze-dried Lcc and mixed feed containing Dex for one year from August 2004. After supplementation with the synbiotic, milk yields and components of Group B were compared with those of Group A in the August, December of 2004, April and August of 2005. Milk yields of Group B were greater than those of Group A. There were significant differences (p<0.01 or 0.05) between these groups for all values. Furthermore, total amounts of fat, protein and solid non-fat in Group B significantly increased in comparison with those of Group A. In addition, the somatic cell counts of Group A significantly increased in August of 2004 and 2005 in comparison with those of Group B. Thus, the new synbiotic consisting of Lcc and Dex can increase the milk production of Holstein dairy cows throughout the year.  相似文献   
98.
Diesel exhaust particles (DEPs) are particulate matter from diesel exhaust containing many toxic compounds, such as polyaromatic hydrocarbons (PAHs). Some toxicities of PAH are considered to express via aryl hydrocarbon receptor (AhR). We hypothesized that the male reproductive toxicity of DEPs may depend on PAHs. BALB/c male mice received 24.7, 74.0 or 220 microg/mouse DEP suspension or vehicle injected into the dorsal subcutaneous layer 10 times during 5 weeks. The mice were euthanized, and blood and organs were collected 2 weeks after the last treatment. The epididymis weights, relative epididymis weights per body weight and daily sperm productions and viabilities of the 74.0 and 220 microg/mouse DEP-treated groups decreased significantly compared with those of the vehicle group. The total incidence of sperm abnormalities in the 74.0 and 220 microg/mouse DEP-treated groups increased significantly compared with the vehicle group. The seminiferous epithelium area ratios of the 74.0 and 220 microg/mouse DEP-treated groups were significantly higher compared with the vehicle and 24.6 microg/mouse DEP-treated groups. The ratios of seminiferous tubules with elongated-type spermatids in the 74.0 and 220 microg/mouse DEP-treated groups were significantly decreased compared with the vehicle group. The testosterone level and hepatic ethoxyresorufin-O-deethylase (EROD) activity as an indirect index of AhR activity in the 74.0 microg/mouse DEP-treated group were significantly increased compared with those of the vehicle group. These results clearly demonstrated that DEPs suppress testicular function, especially spermatogenesis and sperm motility. These effects may be AhR dependent.  相似文献   
99.
The majority of somatic cell nuclear transferred (SCNT) embryos die before or after implantation. Many studies have focused on morphological remodeling of the donor nucleus and its associated cytoskeletal structures in the early events of nuclear transfer. However, little is known about the 2-cell stage of SCNT embryos after the first division. In this study, we compared the morphological status of chromosomal division during the 1-cell stage to the 2-cell stage in SCNT embryos with that in intracytoplasmic sperm injection (ICSI) embryos. The microtubules and cytoplasmic asters, which are related to chromatin segregation, disappeared at the pronuclear stage, although formation of the first mitotic spindle was normal in both the SCNT and ICSI embryos. However, nuclear fragmentation was observed in 30% of the 2-cell SCNT embryos and 12% of the 2-cell ICSI embryos. Nuclear fragmentation was present in both blastomeres of these embryos. No apoptotic DNA fragmentation was observed in TdT-mediated dUTP-biotin Nick End Labeling (TUNEL) assays for either the SCNT or ICSI embryos. In both the SCNT and ICSI embryos, the distribution of chromosomes in the first mitotic spindle was disturbed during the process of division from the 1-cell stage to the 2-cell stage. These results suggest that loss of SCNT embryos just before or after implantation may be due to an abnormal chromosome distribution at the 2-cell stage.  相似文献   
100.
OBJECTIVE: To investigate the diuretic effects, tolerability, and adverse effects of furosemide and torsemide after short- and long-term administration in healthy dogs. ANIMALS: 8 mixed-breed dogs. PROCEDURES: In a crossover study, furosemide (2 mg/kg), torsemide (0.2 mg/kg), or placebo (bifidobacterium [1 mg/kg]) was administered orally to each dog every 12 hours for 14 days. Blood and urine samples were collected before the study (baseline data) and at intervals on the 1st (short-term administration) and 14th day (long-term administration) of treatment for assessment of urine volume and specific gravity and selected clinicopathologic variables including BUN, creatinine, and aldosterone concentrations, and creatinine clearance. RESULTS: Compared with the baseline value, short-term administration of furosemide or torsemide immediately increased urine volume significantly; after long-term administration of either drug, urine specific gravity decreased significantly. Compared with the effect of placebo, the 24-hour urine volume was significantly increased after short-term administra-tion of furosemide or torsemide. In addition, it was significantly increased after long-term administration of torsemide, compared with that of short-term administration. Long-term administration of furosemide or torsemide increased the BUN and plasma creatinine con-centrations, compared with the baseline value. Compared with the baseline value, plasma aldosterone concentration was significantly increased after long-term administration of either drug and was significantly higher after torsemide treatment than after furosemide treatment. CONCLUSIONS AND CLINICAL RELEVANCE: In dogs, diuretic resistance developed after 14 days of furosemide, but not torsemide, administration; however, both loop diuretics were associated with increased BUN and plasma creatinine concentrations, compared with values before treatment.  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