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   169篇
  免费   3篇
林业   29篇
农学   18篇
  25篇
综合类   3篇
农作物   12篇
水产渔业   16篇
畜牧兽医   48篇
园艺   6篇
植物保护   15篇
  2023年   2篇
  2022年   6篇
  2021年   6篇
  2020年   5篇
  2019年   4篇
  2018年   10篇
  2017年   10篇
  2016年   6篇
  2015年   4篇
  2014年   7篇
  2013年   24篇
  2012年   18篇
  2011年   10篇
  2010年   7篇
  2009年   3篇
  2008年   9篇
  2007年   6篇
  2006年   1篇
  2005年   4篇
  2004年   2篇
  2003年   2篇
  2001年   3篇
  2000年   1篇
  1997年   1篇
  1996年   1篇
  1995年   1篇
  1994年   1篇
  1985年   2篇
  1984年   2篇
  1977年   2篇
  1976年   1篇
  1971年   2篇
  1970年   1篇
  1969年   2篇
  1967年   2篇
  1966年   1篇
  1963年   1篇
  1962年   1篇
  1961年   1篇
排序方式: 共有172条查询结果,搜索用时 15 毫秒
81.
Immune privileged mesenchymal stem cells (MSCs) can differentiate into multiple cell types and possess great potential for human and veterinary regenerative therapies. This study was designed with an objective to isolate, expand and characterize buffalo bone marrow‐derived MSCs (BM‐MSCs) at molecular and cellular level. Buffalo BM‐MSCs were isolated by Ficoll density gradient method and cultured in Dulbecco’s modified Eagle’s medium supplemented with fetal bovine serum (FBS). These cells were characterized through alkaline phosphatase (AP) staining, colony‐forming unit (CFU) assay, mRNA expression analysis (CD 73, CD 90, CD 105, Oct4 and Nanog), immunolocalization along with flow cytometry (Stro 1, CD 73, CD 105, Oct4, Sox2 and Nanog) and in situ hybridization (Oct4 and Sox2). Multilineage differentiation (osteogenic, adipogenic and chondrogenic) was induced in vitro, which was further assessed by specific staining. Buffalo BM‐MSCs have the capacity to form plastic adherent clusters of fibroblast‐like cells and were successfully maintained up to 16th passage. These cells were AP positive, and further CFU assay confirmed their clonogenic property. RT‐PCR analysis and protein localization study showed that buffalo BM‐MSCs are positive for various cell surface markers and pluripotency markers. Cytoplasmic distribution of mRNA for pluripotency markers in buffalo BM‐MSCs and multilineage differentiation were induced in vitro, which was further assessed by specific staining. To the best of our knowledge, this is the first report of buffalo BM‐MSCs, which suggests that MSCs can be derived and expanded from buffalo bone marrow and can be used after characterization as a novel agent for regenerative therapy.  相似文献   
82.
Johne's disease (JD), or paratuberculosis is a fatal enteritis of animals caused by infection with Mycobacterium avium subspecies paratuberculosis (Map). There may be a long subclinical phase with no signs of clinical disease.  相似文献   
83.
Angular leaf spot (ALS), an important disease of common bean (Phaseolus vulgaris), is caused by the fungus Pseudocercospora griseola. This pathogen has a wide genetic variability and, therefore, poses a challenge to integrated disease management. The use of resistant cultivars is difficult; hence, the application of fungicides has been a common practice in common bean cultivation. P. griseola strains were morphophysiologically characterized and their sensitivity to common fungicides used to control ALS was studied. The strains were evaluated for sporulation capacity and a representative sample of 34 strains was bioassayed to determine their sensitivity to commercial concentrations of five fungicides, namely pyraclostrobin, mancozeb, pyraclostrobin + metconazole, chlorothalonil and tebuconazole. Another sample of 29 strains was studied for conidial germination and dimensions. Sporulation capacity ranged from 0.88 to 27.67 × 104 conidia/ml and germination percentage ranged from 39% to 72%. The large differences among strains suggest a wide genetic variability among the strains. A wide variability in aggressiveness of P. griseola was observed, which has consequences for breeding programmes aimed at resistance. The behaviour of pathogen strains differed in every fungicide evaluated, even in a population that has not been under selection pressure in the field. These results confirm the need for further studies and may guide future research with this pathogen.  相似文献   
84.
85.
86.
The study was to examine the effects of dietary L. aspera on growth performance, physio-metabolic response and health status of Rita rita fish reared in tanks for 60 days. Six experimental diets were formulated containing 0 g/kg, 3 g/kg, 6 g/kg, 9 g/kg and 12 g/kg L. aspera and designated as D0, D3, D6, D9 and D12 respectively. The inclusion of L. aspera at graded levels resulted in significantly varying effects on growth performance where the weight gain (%), specific growth rate (SGR) and feed conversion efficiency (FCE) were significantly higher (p<0.05) in D6 and D9 groups than others. The protease and amylase activities were elevated in L. aspera supplemented groups than the control group (p<0.05), whereas lactate dehydrogenase, malate dehydrogenase and serum transaminase enzyme activities were significantly reduced with the increasing level of L. aspera and comparatively higher activities of the respective enzymes were found in the control group. The activities of oxidative stress enzymes were significantly higher (p<0.05) in the D9 group and lower in control. The blood glucose level significantly decreased with the increasing level of L. aspera in the experimental diets. The L. aspera supplemented fish had significantly higher liver glycogen, serum protein, albumin and globulin than control group. Red blood cell count was significantly higher (p<0.05) in D6-D12, whereas white blood cell count and haemoglobin content were significantly higher (p<0.05) in D6 and D9 groups. Regression analysis showed that L. aspera at the level of 7.3–7.9 g/kg is optimum for better growth and feed efficiency.  相似文献   
87.
Twenty two lines/accessions belonging to 5 species ofCelosia were analysed for their nutritional and antinutritional composition. The nutrient contents, vitamin C varied from 18.8 to 53.6 mg/100 g, carotenoids 9.1 to 15.1 mg/100g, protein 2.1 to 5.9%, while the antinutritional factors, nitrate 0.18 to 0.46% and oxalate 0.98 to 3.93%. Moisture ranged 81 to 89%. Variation of these parameters with leaf position and the amino acids profile of some promising lines was also evaluated.  相似文献   
88.
A male chimpanzee was presented with a chronic swelling near the left cheek region. Various attempts to treat the chimpanzee went in vain. Vices of the animal, emotional attitude of his family members, and rules and regulations of the Central Zoo Authority made the treatment a challenging task. Meanwhile, the swelling turned into an open wound because of the female chimpanzee that further aggravated the situation. Proper behavioral study of the subject, positive reinforcement training, and accurate treatment protocol resulted in complete healing of the wound without any complications.  相似文献   
89.
Summary

Strawberry (Fragaria ananassa Duch.) is a rich source of minerals, vitamins, and anti-oxidants, and has a unique flavour and aroma. However, there is little information on the genetic variability and inheritance of mineral elements in strawberry. This is important as it can influence the selection of better genotypes and suitable breeding approaches for improvements in the nutritional quality of fruit. The objectives of the present study were, therefore, to estimate the variability, inheritance, and inter-relationships of mineral elements, to identify mineral-rich and productive genotypes, and to suggest suitable breeding approaches. A significant genotypic mean square for all the minerals studied indicated sufficient variation among genotypes. Our results also indicated that the effect of genotype on the mineral content of fruit was stronger than that of environment. Six genotypes, namely ‘Ofra’, ‘Sweet Charlie’, ‘Elista’, ‘Festival’, ‘Camarosa’, and ‘Douglas’ were found to have higher mineral contents as well as better fruit yields, and therefore could be useful in further breeding programmes. N, K, Ca, Mg, Fe, Mn, Zn, and Cu contents, together with fruit yield, could be improved by selection and hybridisation as these traits showed high heritability (> 80%) and high genetic advance as a percentage of the mean (> 40%), while recurrent selection was suitable for increasing P contents, which showed moderate heritability (> 79.81%) and low genetic advance as a percentage of the mean (> 33.86%). Moreover, Mg and N contents could be used as reliable tools with which to identify the most productive and mineral-rich genotypes, as indicated by correlation and path analysis. Studies on such genetic estimates will increase our understanding of the inheritance of mineral contents and affect the design of crop improvement strategies.  相似文献   
90.
An 84-day feeding trial was conducted to study the effect of replacing dietary fishmeal with dried chicken viscera meal (CVM) on the growth (net biomass gain, specific growth rate, SGR), feed acceptability, feed conversion ratio (FCR), protein efficiency ratio (PER) and carcass composition of Clarias batrachus fingerlings. Triplicate groups of fingerlings with mean initial body weight of 13.35 g were fed on six iso-nitrogenous and iso-lipidic diets. The control diet (CVM0) used marine by-catch fishmeal as the sole source of animal protein. In the other five diets (CVM100–CVM500), 20–100% of fishmeal was substituted by dried CVM at 20% increments. The highest body weight gain, SGR and PER, and the lowest FCR were observed in fish fed a diet containing 300–500 g CVM kg−1. The fish accumulated increasing quantities of lipids and decreasing levels of ash in their carcasses with increasing levels of dietary CVM.  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