全文获取类型
收费全文 | 300篇 |
免费 | 16篇 |
国内免费 | 41篇 |
专业分类
林业 | 6篇 |
农学 | 24篇 |
14篇 | |
综合类 | 111篇 |
农作物 | 16篇 |
水产渔业 | 33篇 |
畜牧兽医 | 122篇 |
园艺 | 7篇 |
植物保护 | 24篇 |
出版年
2022年 | 3篇 |
2021年 | 6篇 |
2020年 | 3篇 |
2019年 | 8篇 |
2018年 | 5篇 |
2017年 | 7篇 |
2016年 | 12篇 |
2015年 | 11篇 |
2014年 | 20篇 |
2013年 | 24篇 |
2012年 | 24篇 |
2011年 | 18篇 |
2010年 | 31篇 |
2009年 | 19篇 |
2008年 | 20篇 |
2007年 | 22篇 |
2006年 | 17篇 |
2005年 | 17篇 |
2004年 | 11篇 |
2003年 | 10篇 |
2002年 | 13篇 |
2001年 | 12篇 |
2000年 | 9篇 |
1999年 | 2篇 |
1998年 | 4篇 |
1997年 | 5篇 |
1996年 | 7篇 |
1995年 | 1篇 |
1994年 | 5篇 |
1993年 | 3篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1955年 | 1篇 |
排序方式: 共有357条查询结果,搜索用时 31 毫秒
21.
地高辛标记cDNA探针检测苹果茎痘病毒 总被引:3,自引:0,他引:3
Partial sequence(314 bp) of ASPV was cloned and used as a probe labelled with digoxigenin-11dUTP. The total RNA extracted from samples with Apple stem pitting virus and a series of dilutions of plasmid with ASPV-cDNA were detected by dot blot hybridization. The results showed that the probe was sensitive and specific. The probe couldn't hybridize with total RNA of Apple stem grooving virus, Apple mosaic virus and Apple chlorotic leaf spot virus samples as well as negative control, only hybridized with that extracted from dormant shoot infected with ASPV. The sensitivity for detection of plasmid contained ASPV-cDNA was 1.64 μg. 相似文献
22.
为筛选与线虫感染性相关的基因,本研究以猪蛔虫为对象,构建猪蛔虫感染期幼虫差异表达消减cDNA文库,为研究线虫期特异性发育的分子机制奠定基础。分别提取感染期幼虫和其它各期幼虫及成虫的总RNA,纯化mRNA后,采用Clontech公司PCR-selectTM试剂盒进行反转录合成cDNA并进行抑制消减杂交(SSH),构建猪蛔虫感染期幼虫差异表达的消减cDNA文库,并采用Southern斑点杂交进行消减效率的检测。随机从文库中抽取45个克隆进行测序及在线BLAST分析。试验结果表明,感染期幼虫差异表达的消减cDNA文库具有较强的特异性;在得到的41个表达序列标签(ESTs)中,有40个ESTs与已报道的基因有较高的相似性,主要代表猪蛔虫第三期幼虫基因和成虫头部基因,有1个cDNA片段可能代表新基因。猪蛔虫感染期幼虫差异表达消减cDNA文库的成功构建,为进一步研究幼虫发育差异表达基因的功能奠定了基础。 相似文献
23.
24.
根据其他植物PAL基因的DNA序列的保守区域,设计了一对简并引物,经PCR扩增,得到一条862 bp的特异性扩增带。将PCR扩增产物构建到T-载体并测序,获得了862 bp DNA序列。通过分析所得的862 bp DNA序列及其编码的氨基酸序列,与其他植物PAL基因的DNA序列和蛋白质序列分别进行比较,证实了所得序列为银杏PAL基因的部分序列。Gbpal1已经被Genebank收录,序列号为AY578145。Southern杂交结果表明银杏PAL是一个多基因家族。 相似文献
25.
Secretoglobin and Transferrin Expression in Bronchoalveolar Lavage Fluid of Horses with Chronic Respiratory Disease
下载免费PDF全文
![点击此处可从《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》网站下载免费的PDF全文](/ch/ext_images/free.gif)
M. Miskovic Feutz L.L. Couetil C.P. Riley X. Zhang J. Adamec R.E. Raskin 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2015,29(6):1692-1699
Background
Lower expression of secretoglobin and transferrin has been found in the bronchoalveolar lavage fluid (BALF) of a small number of horses with experimentally induced signs of recurrent airway obstruction (RAO) compared to healthy controls.Hypothesis/Objectives
Secretoglobin and transferrin BALF expression will be similarly decreased in horses with naturally occurring clinical signs of RAO and in horses with experimentally induced clinical signs of RAO as compared to healthy controls and intermediate in horses with inflammatory airway disease (IAD).Animals
Recurrent airway obstruction‐affected and control horses were subjected to an experimental hay exposure trial to induce signs of RAO. Client‐owned horses with a presumptive diagnosis of RAO and controls from the same stable environments were recruited.Methods
Pulmonary function and BALF were evaluated from control and RAO‐affected research horses during an experimental hay exposure trial (n = 5 in each group) and from client‐owned horses (RAO‐affected horses, n = 17; IAD‐affected horses, n = 19; healthy controls, n = 5). The concentrations of secretoglobin and transferrin in BALF were assessed using Western blots.Results
Naturally occurring and experimentally induced RAO horses had similar decreases in BALF transferrin expression, but secretoglobin expression was most decreased in naturally occurring RAO. Secretoglobin and transferrin expression were both lower in BALF of RAO‐affected horses than in IAD‐affected and control horses.Conclusions and Clinical Importance
Secretoglobin and transferrin expression is decreased in BALF of RAO‐affected horses after both experimental and natural exposure. Secretoglobin and transferrin likely play clinically relevant roles in the pathophysiology of RAO, and may thus be used as biomarkers of the disease. 相似文献26.
A variety of methods have been used to identify Mycobacterium spp. isolated from snakehead and Siamese fighting fish, including biochemistry, mycolic acid profiles and antibody-based methods. However, these methods are unable to differentiate between different species of Mycobacterium . Polymerase chain reaction (PCR) followed by reverse cross blot hybridization (RCBH) was adapted in this study to speciate aquatic mycobacteria. The method was highly specific for Mycobacterium spp. and identified the bacteria to species level with a detection limit of 100 fg DNA, equivalent to 20 mycobacteria. Twenty-nine isolates previously collected and cultured from Siamese fighting fish (10 isolates) and snakehead (19 isolates) during outbreaks of mycobacteriosis were analysed using PCR–RCBH. Six of the Siamese fighting fish isolates and nine of the snakehead isolates were identified as Mycobacterium fortuitum , while the remainder were classified as M. marinum . Notably, two isolates recovered from snakehead and Siamese fighting fish, previously identified as M. poriferae and M. piscicida , respectively, were confirmed to be M. fortuitum . 相似文献
27.
28.
应用Gateway重组技术构建CSBV非结构蛋白,RNA依赖的RNA聚合酶(RNA-dependent RNA polymerase,RdRp)的原核表达载体,将重组表达载体转化大肠杆菌Rosetta,经异丙基硫代-β-D-半乳糖苷(Isopropylβ-D-1-Thiogalactopyranoside,IPTG)诱导获得RdRp基因原核表达蛋白.以重组蛋白为抗原免疫新西兰兔制备相应的多克隆抗体,Western blot检测表明,该抗体能与RdRp重组蛋白和感病中华蜜蜂幼虫蛋白特异性结合,说明获得的抗体特异性高.利用制备的抗体进行免疫荧光标记,发现其能特异地定位在感病中华蜜蜂血淋巴细胞内. 相似文献
29.
R. M. Jacobs J. L. Heeney M. A. Godkin K. E. Leslie J. A. Taylor C. Davies V. E. O. Valli 《Veterinary research communications》1991,15(6):463-474
A newly developed milk dot blot test was used to detect anti-bovine leukaemia virus (BLV) antibody in milk samples from 2079 lactating adult cows from among 61 herds. The milk dot blot test was highly repeatable; the concordance rate, compared with the agar gel immunodiffusion test performed on serum, was 83.5%. All herds contained BLV-positive cows; the prevalence rate was 36%. BLV-positive cows tended to come from larger herds and were older and more often later in lactation. Fourteen production and related variables (herd size, age, days open, days in milk, milk somatic cell count, milk, fat, and protein produced in the current lactation, projected production of milk, fat, and protein, and breed class average deviations for milk, fat, and protein) were compared between BLV-positive and BLV-negative cows. Although somatic cell count, milk produced, and projected production of milk and protein were related significantly to BLV status using simple tests of association, once the variables herd size, age and days in milk were controlled, these differences were removed. Further analyses using logistic (outcome: individual cow BLV status) and least-squares regression (outcome:herd proportion of BLV-positive cows) failed to show an association between any of the measured production or related variables and BLV-positivity. We concluded that the effect of BLV on production and related variables in dairy cows was below the sensitivity of our analytical techniques or was non-existent.Abbreviations ABCA
herd average breed class average for milk, fat, and protein production
- AVGAGE
average age of the herd
- ADIM
herd average for days in milk
- AGID
agar gel immunodiffusion
- AVGSCC
herd average milk somatic cell count
- BCA
breed class average, a milk, fat and protein production index calculated by comparing a cow's actual 305-day lactation production to the corresponding BCA standard for the same breed, age, and month of calving
- BLV
bovine leukaemia virus
- CALVINT
calving interval
- COWAGE
cow age
- DBCA
breed class average deviation for milk, fat, and protein production, the difference between an individual cow's BCA and the herd average
- DIM
days in milk
- HS
herd size corresponding to the number of lactating cows in a herd
- LACT
actual amount of milk, fat, and protein produced in a cow's lactation
- ODHIC
Ontario Dairy Herd Improvement Corporation
- PCTPOS
percentage of herd that is BLV-positive
- PROJ
projected 305-day production for milk, fat, and protein by fitting to a standard lactation curve adjusted for days in milk and age at calving
- RHBCA
rolling herd average for breed class average for milk, fat, and protein production, the average for all cows that completed a lactation (cows must have completed a 305-day lactation) during the previous 12 months
- SCC
milk somatic cell count 相似文献
30.