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   128篇
  免费   4篇
  国内免费   2篇
林业   16篇
农学   3篇
  23篇
综合类   11篇
农作物   4篇
水产渔业   24篇
畜牧兽医   47篇
园艺   1篇
植物保护   5篇
  2022年   4篇
  2021年   4篇
  2020年   5篇
  2018年   2篇
  2017年   3篇
  2016年   3篇
  2015年   1篇
  2013年   17篇
  2012年   3篇
  2011年   6篇
  2010年   7篇
  2009年   9篇
  2008年   3篇
  2007年   11篇
  2006年   14篇
  2005年   6篇
  2004年   9篇
  2003年   6篇
  2002年   8篇
  2001年   5篇
  2000年   4篇
  1999年   1篇
  1998年   1篇
  1993年   1篇
  1992年   1篇
排序方式: 共有134条查询结果,搜索用时 31 毫秒
61.
Three beagle dogs were inoculated with mice spleen/liver homogenate infected with Ehrlichia species detected from Ixodes ovatus (EIO) and one dog was used as a control. All three infected dogs did not show clinical signs of disease except for mild pyrexia throughout the 41-day study period. Splenomegaly was observed from Day 7 post-inoculation (p.i.) in two of the dogs. Hematological and biochemical abnormalities included mild thrombocytopenia, hypoproteinaemia, hypoalbuminaemia and increased C-reactive protein values. One of the dogs' splenic aspirate sample was PCR-positive for Ehrlichia Day 7 p.i. and another dogs' blood and bone marrow aspirate sample was PCR-positive Day 41 p.i. Sequence analysis of the PCR products showed 100% homology with the 16SrRNA partial gene sequence of Ehrlichia sp. HF565. Antibody titers to EIO were observed in all three experimentally infected dogs starting from the first week p.i. and cross-reactivity with Ehrlichia canis was detectable in one of the dogs starting Day 7 p.i. These data suggest that infection of dogs with EIO is possible, though is probably of low pathogenic importance. Cross-reactivity of EIO infected dog serum with E. canis raises the likelihood of false E. canis seropositive dogs.  相似文献   
62.
Capsinoids are a group of nonpungent capsaicinoid analogues produced in Capsicum fruits. They have similar bioactivities to capsaicinoids such as suppression of fat accumulation and antioxidant activity. They are more palatable ingredients in dietary supplements than capsaicinoids because of their low pungency. Previous studies on nonpungent Capsicum annuum cultivars showed that capsinoid biosynthesis is caused by loss-of-function putative aminotransferase (p-amt) alleles. This study showed that three mildly pungent cultivars of Capsicum chinense (Zavory Hot, Aji Dulce strain 2, and Belize Sweet) contain high levels of capsinoid. It was shown that these cultivars have novel p-amt alleles, which contain mutations that differ from those of C. annuum. Sequence analysis of p-amt in Belize Sweet revealed that a 5 bp insertion (TGGGC) results in a frameshift mutation. A transposable element (Tcc) was found in the p-amt of Zavory Hot and Aji Dulce strain 2. Tcc has features similar to those of the hAT transposon family. This was inserted in the fifth intron of Zavory Hot and in third intron of Aji Dulce strain 2. The p-amt alleles harboring Tcc cannot produce an active p-AMT. These mildly pungent cultivars will provide a new natural source of capsinoids.  相似文献   
63.
管道进口空气吸入的临界水深试验研究   总被引:1,自引:0,他引:1  
制作1∶3比尺的大小水槽模型,试验研究了灌溉管道进口空气吸入的形式及临界水深与管道流速的关系,得出空气吸入的形式及临界水深与水槽内水流的紊动状态有关,且临界水深随流速的增加而增加的结论。相似性分析表明,临界水深在流速较小时大致符合0.2次方准则,而当流速较大时接近流速一致准则。此外,还根据试验结果对日本有关最小水深标准值进行了讨论  相似文献   
64.
SUMMARY: Adenocarcinomatous growths comprising glandular cavities surrounded by cuboidal to low columnar cells and a large amount of mucus produced by the mucous cells, were observed in the the gastric lymph nodes of a harbor seal Phoca largha. The seal was stranded on the coast of Toyama Bay, Sea of Japan, on 2 March, 1998. Necroscopic examination also showed the animal had significant signet ring cell carcinoma in the stomach, as has been reported elsewhere. The adenocarcinoma may have developed from metastatic cells arising in the gastric carcinoma.  相似文献   
65.
Oxaliplatin (OXL) therapy often causes side effects including chronic peripheral neuropathy. We investigated the pain-relieving effects of recombinant human lactoferrin (rhLf) as well as a long-acting IgG-Fc fused rhLf (rhLf-Fc) on OXL-induced neuropathic pain. We used the hLf in this study, because the homology between mouse Lf and hLf is higher than that of bovine Lf. In addition, rhLf-Fc is expected to enhance the analgesic effect due to the life extension effect in the body. We administered OXL (2 mg/kg, i.v.) to mice twice weekly for 4 weeks. Phosphate buffered saline (PBS), rhLf (100 mg/kg, i.p.) or rhLf-Fc (100 mg/kg, i.p.) was administered once a week from day 15 to 32. We also assessed the continuous infusion of same drugs (10 mg/kg/day) into the external jugular vein by using an osmotic pump. Both of rhLf and rhLf-Fc significantly reduced the hypersensitivity to mechanical stimulation when they were administered intraperitoneally. The continuous infusion of rhLf resulted in a more pronounced effect. Histopathological analysis of sciatic nerve showed that both rhLf and rhLf-Fc tended to reduce nerve fiber damage, but no significant difference was observed in nerve fiber cross-sectional area. Therefore, it was suggested that rhLf or rhLf-Fc injection could be an option for controlling neuropathic pain, which are side effects of OXL.  相似文献   
66.
Decreased cardiac contractility is a central feature of systolic heart failure. Existing drugs increase cardiac contractility indirectly through signaling cascades but are limited by their mechanism-related adverse effects. To avoid these limitations, we previously developed omecamtiv mecarbil, a small-molecule, direct activator of cardiac myosin. Here, we show that it binds to the myosin catalytic domain and operates by an allosteric mechanism to increase the transition rate of myosin into the strongly actin-bound force-generating state. Paradoxically, it inhibits adenosine 5'-triphosphate turnover in the absence of actin, which suggests that it stabilizes an actin-bound conformation of myosin. In animal models, omecamtiv mecarbil increases cardiac function by increasing the duration of ejection without changing the rates of contraction. Cardiac myosin activation may provide a new therapeutic approach for systolic heart failure.  相似文献   
67.
Asparagus (Asparagus officinalis L.) is a dioecious plant. In general, male and female plants are used for open-field culture and intensive cultivation, respectively. Farmers distinguish between the sexes by observing the form of the flower organs. However, because flowering begins 2?C3 years after planting, the sexes cannot be differentiated at transplantation by using this method, and planting of an all-male population is not possible. In this study, the usefulness of loop-mediated isothermal amplification (LAMP), a simple method of gene amplification, for sex distinction at the DNA level was determined. In addition, the phenotypic differences in seeds and seedlings of male and female plants were investigated for application as a method of early sex distinction. By using the LAMP method, the sex could be correctly identified in 100% of the seedlings, suggesting that this method is effective for sex distinction at the gene level. Principal component analysis was conducted with 11 selected parameters after investigating the seeds and seedlings of both male and female plants. The results revealed that male plants tend to have many stalks or cladophylls and female plants tend to have large plant forms, suggesting that the sexes can be distinguished by the external appearance of the seedlings before planting. LAMP and observation of the seedling phenotypes could be useful methods of sex distinction for increasing the efficiency of asparagus breeding.  相似文献   
68.
Fractional analysis of phosphorus compounds in plant tissue has been carried out by many workers, and reported on tobacco plant by Holden (1) and Komatsu (2). The fractional distribution of foliar absorbed phosphorus was investigated by Yatazawa (3) who indicated that the phosphorus was first converted into the phosphate-ester as an intermediate substance on the phosphorus metabolism. The methods of fractional analysis used by these authors were based on the method proposed by Page and Umbereit (4) in which they used trichloroacetic acid as the first extracting reagent. Recently, in order to separate the protein bound phosphorus, Wildmann, Campell and Bonner (5) adopted the salting-out method without using trichloroacetic acid. They reported that the protein-bound phosphorus plays an important role and is in the dynamic state. Fujiwara and Kadowaki (6) paid attention to the phosphorus bound to cytoplasmic protein as energy-rich phosphate compounds, and adopted the method so as to separate such compounds. In order to reveal the utilization of foliar absorbed phosphorus by the tobacco plant, the fractional distribution of phosphorus was examined. In this paper, the degree of change to organic phosphorus was taken as an index of phosphorus utilization. Paper electrophoresis was used for this purpose because the inorganic and the protein-bound phosphorus could be separated easily.  相似文献   
69.
Der größere Teil des Stickstoffhaltiges Düngesmittels sind anorganische Substanzen, und nur das Harnstoff und Kalkstickstoff können organische genannt werden, aber seine Geschwindigkeiten der Zersetzung im Boden sind ziemlich schnell, also sie haben keine dauernde Wirkung, sondern haben schnell Düngewirkung.  相似文献   
70.
Im ersten Bericht (1) wir beschrieben eine Weise die rein Monomethlolharnstoff im große Ausbeute darstellt, aber es ist unklar, ob dem Düngemittel oder einem Bestandteil des komplex Düngemittel, Monomethylolharnstoff angemesst ist oder nicht. Also, wir untersuchten einige Eigenschaften wie folgt.  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