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   152篇
  免费   14篇
林业   11篇
农学   15篇
  24篇
综合类   10篇
农作物   15篇
水产渔业   25篇
畜牧兽医   35篇
园艺   7篇
植物保护   24篇
  2023年   2篇
  2022年   8篇
  2021年   2篇
  2020年   7篇
  2019年   7篇
  2018年   12篇
  2017年   13篇
  2016年   4篇
  2015年   6篇
  2014年   8篇
  2013年   18篇
  2012年   10篇
  2011年   15篇
  2010年   11篇
  2009年   6篇
  2008年   3篇
  2007年   4篇
  2006年   2篇
  2005年   5篇
  2004年   2篇
  2003年   4篇
  2002年   3篇
  2001年   2篇
  1999年   1篇
  1998年   1篇
  1996年   1篇
  1995年   2篇
  1991年   1篇
  1988年   1篇
  1987年   1篇
  1985年   1篇
  1983年   1篇
  1982年   2篇
排序方式: 共有166条查询结果,搜索用时 17 毫秒
61.
62.
The aim of the present study was to evaluate acellular dermal matrix (ADM) of rat origin for the repair of ventral hernia in horses. The skin from rats, to be used as a graft, was de-epithelialized using hypertonic solution and further decellularized with 0.5% sodium dodecyl sulfate and 0.25% tri-(n-butyl)-phosphate. Under general anesthesia, the hernial ring was exposed and repaired with the ADM graft using inlay graft technique. Blood samples were collected at postimplantation days 0, 15, and 30 and were used for sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis to assess the serum protein concentration of the animals, as well as for gelatin zymography for the identification of matrix metalloproteinases. All animals had an uneventful recovery without clinical signs of wound dehiscence, infection, or recurrence of hernias during 6-month follow-up period. Sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis of concentration of the serum proteins revealed that this was increased at day 15 and had decreased again at day 30. Gelatin zymography showed only one major band of 92 kDa in the serum of all the horses with the implant, but the relative amount of 92 kDa was higher at day 15 as compared with day 0 and day 30. It may be concluded that ADM of rat origin can be used safely in horses for repair of ventral hernia.  相似文献   
63.
The puroindoline genes Pina-D1 and Pinb-D1 located at the Ha locus on chromosome 5D of common wheat are considered the most important genetic determinants of grain hardness. The recent identification of Pinb-2 genes on group 7 chromosomes emphasises the need for detailed analysis of the genetics of this important trait. This study focussed on the analysis of Pinb-2 genes from accessions of hexaploid, tetraploid and diploid wheat, to address key questions related to their diversity and possible roles. Extensive DNA sequence heterogeneity was identified in the form of single nucleotide polymorphisms (SNPs), leading to seventeen reproducible haplotypes, of which thirteen are new. The results confirmed the known groups Pinb-2v1 to Pinb-2v5, identified a new group Pinb-2v6, and showed that the Pinb-2 genes comprised a small multigene family, at least in some genomes. The putative proteins exhibited changes at the important tryptophan-rich domain as well as basic and hydrophobic residues. A new Pina-D1 allele (at Ha locus) was also identified, designated Pina-D1t, with a premature stop codon at the TRD. Additionally, peptides designed on PINB-2 proteins displayed activity against bacteria and phytopathogenic fungi. The data strongly support the Pinb-2 genes being functionally relevant to roles including influencing grain texture.  相似文献   
64.
Amino acid surfactants are high-value surfactants which have excellent emulsifying characteristics and minimal toxicity to the living body. Enzymatic synthesis of palm kernel amino acid surfactant was optimized by response surface methodology (RSM) using palm kernel olein (PKO) and l(+)-lysine catalyzed by Lipozyme RM IM. The reaction was performed in batch mode stirred tank reactor (STR) with one multi-bladed impeller. A central composite rotatable design (CCRD) was employed to evaluate the interactive effects of various parameters. The parameters were temperature (A): (40.00–70.00 °C), impeller speed (B): (100.00–400.00 rpm), substrates ratio (C): (1.00–4.00 mmol) and enzyme amount (D): (5.00–8.00 g). The optimum condition derived via RSM at fixed reaction time of 24 h was temperature; 47.50 °C, impeller speed; 323.96 rpm, substrates ratio; 3.25 mmol and enzyme amount; 7.25 g. The experimental yield was 89.03% under the optimum condition, which compared well with the maximum predicted value of 93.77%.  相似文献   
65.
Biofloc technology based 45-day indoor growth trial was conducted to evaluate the effect of carbohydrate (CHO), molasses supplementation on two developmental stages viz, juvenile (J) and sub-adult (SA) of Penaeus monodon in zero-water exchange system. P. monodon juveniles (1.56 ± 0.04 g) and sub-adults (14.32 ± 0.22 g) were stocked in fibre-reinforced plastic tanks (1,000 L) with soil base. Carbohydrate supplementation significantly reduced (p < 0.05) the total ammonia nitrogen (TAN), nitrite-N (NO2-N) and nitrate-N (NO3-N) over the time periods in sub-adult group. However, no significant difference in TAN and NO2-N was observed in juvenile-based treatments. Supplementation of carbohydrate significantly increased (p < 0.05) the water and soil total heterotrophic bacterial (THB) count in both juvenile and sub-adults. Despite increase in total Vibrio count (TVC), lower TVC/THB % was noticed in the water column of J + CHO (0.82) and SA + CHO (0.73) compared to control groups, J ? CHO (1.48) and SA ? CHO (1.21). Supplementation of carbohydrate increased the final body weight in J + CHO (6.51 ± 0.44 g) and SA + CHO (22.52 ± 0.98 g) compared with respective controls, J ? CHO (5.05 ± 0.45 g) and SA ? CHO (20.00 ± 0.33 g). Similarly, significantly lower (p < 0.05) feed conversion ratio and better protein efficiency ratio were recorded in carbohydrate-supplemented juvenile and sub-adults treatment groups. The present study demonstrates that supplementation of carbohydrate reduced the nitrogenous metabolites and significantly enhanced the growth performance of juvenile and sub-adult of P. monodon.  相似文献   
66.
67.
The present study was planned to evaluate the possible transmission of ochratoxin A (OTA) in serum and targeted organs of broilers fed on two levels (500 and 1000 ppb) this toxin in the presence or absence of a toxin deactivator (containing a mycotoxin deactivating yeast Trichosporon mycotoxinivorans) at two inclusion levels (1 and 2 kg/ton of feed) to 270 day-old broiler chicks divided into nine groups (A-I) over a 42 days period. Serum samples were collected at 14, 28 and 42nd day of experiment, whereas, liver and kidney tissues were obtained from broilers slaughtered at 42nd day of experiment. The highest OTA levels were detected in serum, livers and kidneys of OTA treated groups without supplementation of toxin deactivator (groups D and G) at day 42 of experiment, while the residues were significantly (P<0.01) lower in treatment groups (F and I) supplemented with toxin deactivator at 2 kg/ton of feed. The order of OTA level was serum>kidneys>liver.  相似文献   
68.
Genetic diversity of pink-pigmented facultative methylotrophic bacteria belonging to the genus, Methylobacterium, was assessed using 16S ribosomal RNA (rRNA) gene sequencing, amplified ribosomal DNA restriction analysis (ARDRA), and differential carbon-substrate utilization profile in the phyllosphere of cotton, maize, sunflower, soybean, and mentha plants. Methylobacterium populi, Methylobacterium thiocyanatum, Methylobacterium suomiense, M. aminovorans, and Methylobacterium fujisawaense were identified to colonize the phyllosphere of these crop plants. Among these, M. populi found to be the dominating species followed by M. aminovorans. The diversity indices like Shannon index of diversity, Pielou index of evenness, and Margalef index of richness calculated based on combined data of ARDRA, 16S rRNA gene sequence, and differential carbon-substrate utilization revealed that sunflower leaves showed richest methylobacterial diversity, followed by soybean, while cotton and mentha leaves recorded the lowest diversity. The outcome of this study indicates that diversity of Methylobacterium in phyllosphere depends upon the host plant species colonized.  相似文献   
69.
Cell lines provide an important biological tool for carrying out investigations into physiology, virology, toxicology, carcinogenesis and transgenics. Teleost fish cell lines have been developed from a broad range of tissues such as ovary, fin, swim bladder, heart, spleen, liver, eye muscle, vertebrae, brain, skin. One hundred and twenty-four new fish cell lines from different fish species ranging from grouper to eel have been reported since the last review by Fryer and Lannan (J Tissue Culture Methods 16: 87–94, 1994). Among the cell lines listed, more than 60% were established from species from Asia, which contributes more than 80% of total fish production. This includes 59 cell lines from 19 freshwater, 54 from 22 marine and 11 from 3 brackish water fishes. Presently, about 283 cell lines have been established from finfish around the world. In addition to the listing and a scientific update on new cell lines, the importance of authentication, applications, cross-contamination and implications of overpassaged cell lines has also been discussed in this comprehensive review. The authors feel that the review will serve an updated database for beginners and established researchers in the field of fish cell line research and development.  相似文献   
70.
In the present study, a new cell line from the vertebra of mosquitofish Gambusia affinis was successfully established and characterized. The cell line is named as bone Gambusia affinis (BGA) and subcultured for more than 55 passages in Leibovitz's/L15 medium supplemented with 15% FBS at 28°C. The cell line has a modal chromosome number of 48. Molecular characterization of the partial sequence of the coi gene confirmed the origin of the BGA cell line from mosquitofish. These cells exhibited epithelial morphology confirmed by the cytokeratin marker. The BGA cells showed mineralization of their extracellular matrix when stained with alizarin red and von Kossa stain. BGA cells were found to be susceptible to RGNNV and SJNNV strains of betanodavirus (NNV) showing cytopathic effect with multiple vacuolations in the cells. The RT-PCR confirmed the betanodavirus infections in BGA cells. The SEM micrograph showed the morphological changes observed in the cell during virus infection. The in vivo challenge experiment also showed the viral replicating efficiency in the Gambusia affinis with increasing viral titre. Thus, our present results show that the BGA cell line is a useful tool for isolating betanodavirus and could be used to investigate bone cell differentiation and extracellular matrix mineralization.  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