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   85篇
  免费   11篇
林业   5篇
农学   2篇
  6篇
综合类   7篇
农作物   7篇
水产渔业   14篇
畜牧兽医   48篇
园艺   3篇
植物保护   4篇
  2022年   1篇
  2021年   4篇
  2020年   1篇
  2019年   5篇
  2018年   9篇
  2017年   3篇
  2016年   5篇
  2015年   2篇
  2014年   4篇
  2013年   9篇
  2012年   1篇
  2011年   2篇
  2010年   7篇
  2009年   2篇
  2008年   4篇
  2007年   4篇
  2006年   2篇
  2005年   2篇
  2004年   3篇
  2002年   2篇
  2001年   2篇
  2000年   1篇
  1999年   2篇
  1998年   3篇
  1997年   1篇
  1996年   2篇
  1993年   1篇
  1991年   3篇
  1989年   1篇
  1985年   1篇
  1983年   1篇
  1981年   2篇
  1978年   2篇
  1976年   2篇
排序方式: 共有96条查询结果,搜索用时 15 毫秒
91.
A 90‐day experiment was conducted by rearing 1020 prawn juveniles (0.54 ± 0.03 g) in water supplemented with three different concentrations of probiotic bacteria viz. T1 (107 cfu L?1), T2 (108 cfu L?1), T3 (109 cfu L?1) and the control (C) (unsupplemented water), to evaluate probiotic effect of Lactobacillus plantarum. In the present study, the growth parameters (WG%, SGR) and feed utilization parameters (FCR, PER) significantly improved (P < 0.05) in T3. The growth and feed utilization parameters though improved marginally in T1 and T2, the difference was not significant (P > 0.05) compared to the control. The gastro‐intestinal Lactobacillus sp. count increased significantly (P < 0.05) in all the treatment groups, whereas the decrease in harmful bacteria was significant (P < 0.05) in T3 compared to the control. Similarly, the Lactobacillus sp. count in culture water increased significantly (P < 0.05) in all the experimental groups, whereas the decrease in harmful bacteria was significant (P < 0.05) in T2 and T3. The immune parameters (THC, PO and RB activity) and clearance efficiency significantly improved (P < 0.05) in T3 with concurrent decrease (P < 0.05) in cumulative mortality against Aeromonas hydrophila challenge. However, water quality did not improved (P > 0.05) in any of the treatment groups. The results indicate that Lactobacillus plantarum at a minimum concentration of 109 cfu L?1 could be used as water additive to confer its probiotic effect in prawn, Macrobrachium rosenbergii. Moreover, future studies with higher probiotic concentrations should be conducted for its efficient commercial scale field application.  相似文献   
92.
Immunotherapeutic potential of aqueous extract of Ocimum sanctum (O. sanctum) leaf in bovine sub-clinical mastitis (SCM) was investigated. Somatic cell count (SCC), total bacterial count (TBC), milk differential leukocyte count (DLC), phagocytic activity and Phagocytic index and leukocyte lysosomal enzymes like myeloperoxidase and acid phosphatase content were evaluated after intramammary infusion of aqueous leaf extract of O. sanctum. The results revealed that the aqueous extract of O. sanctum treatment reduced the TBC and increased neutrophil and lymphocyte counts with enhanced phagocytic activity and phagocytic index. Similarly, the lysosomal enzymes contents of the milk polymorphonuclear cells (PMNs) were also enhanced significantly in animals treated with the extract. The results suggest that the crude aqueous extract of O. sanctum (leaf) possesses some biologically active principles that are antibacterial and immunomodulatory in nature. As such, the present wok substantiates the therapeutic use of medicinal herb and also emphasizes on the potential of the commonly available non-toxic substances to enhance the mammary immunity.  相似文献   
93.
A series of experiments was performed to examine the effects of blastomere biopsies on subsequent development of IVF-derived bovine embryos. The first experiment was designed to assess the optimal time for blastomere removal. One blastomere was removed either 48 or 72 h after IVF. Biopsy at 48 h resulted in 17.2% of embryos proceeding to the blastocyst stage, which was lower than when biopsies were performed at 72 h (37.5%, p < 0.05). In the second experiment, embryos were cultured either under atmospheric or 5% O(2) following blastomere removal. Biopsies had no effect on rate of blastocyst formation with 36% of controls and 33.7% of biopsied embryos proceeding to that stage. However, culture under 5% O(2) significantly increased the number of blastocysts from 29.9% to 40.3% (p < 0.05). This effect was significant in both biopsied and control embryos. In the final experiment, biopsied embryos were again cultured under different oxygen tension. Blastocysts were collected and cultured individually for 48 h in medium droplets in their respective O(2) concentration after which time the medium was assayed for concentration of interferon-tau (IFN-tau). Reduced O(2) concentration again significantly increased blastocyst formation from 24.9% to 41.9% (p < 0.05). IFN-tau secretion was not affected by biopsies, but culture under atmospheric O(2) resulted in significantly increased IFN-tau concentration in medium droplets (12274.0 +/- 2825.9 pM vs 5046.5 +/- 2562.2 pM; p < 0.05).  相似文献   
94.
Persistent Müllerian duct syndrome (PMDS) is a sex‐limited disorder in which males develop portions of the female reproductive tract. Important consequences of PMDS are cryptorchidism and its sequelae of infertility and increased risk of testicular cancer. Anti‐Müllerian hormone (AMH) and its receptor (AMHR2) induce the regression of the Müllerian ducts in male embryos. In Miniature Schnauzer dogs, the genetic basis has been identified as an autosomal recessive nonsense mutation in AMHR2, but the allele frequency of the mutation is unknown. Thus, the primary objective of this study was to estimate the prevalence of the AMHR2 mutation in North American Miniature Schnauzers, in order to ascertain the value of genetic testing in this breed. An additional objective was to determine whether mutations in AMH or AMHR2 were responsible for PMDS in a Belgian Malinois; this would aid development of a genetic test for the Belgian Malinois breed. Genomic DNA from 216 Miniature Schnauzers (including one known PMDS case) was genotyped for the AMHR2 mutation, and DNA from a single PMDS‐affected Belgian Malinois was sequenced for all coding exons of AMH and AMHR2. The Miniature Schnauzer cohort had an AMHR2 mutation allele frequency of 0.16 and a carrier genotypic frequency of 0.27. The genetic basis for PMDS in the Belgian Malinois was not determined, as no coding or splicing mutations were identified in either AMH or AMHR2. These findings support a benefit to AMHR2 mutation testing Miniature Schnauzers used for breeding or with cryptorchidism.  相似文献   
95.
A total of 17 simple sequence repeat (SSR) markers linked to QTLs (qDTYs) governing grain yield under reproductive stage (RS) drought stress were used to assess the genetic relationship and prospecting new donors for qDTYs among 32 popular upland rice genotypes. These SSR markers generated a total of 36 alleles with an average allele count of 2.1 per locus. Polymorphic information content value of the markers ranged from 0.376 to 0.662 with an average value of 0.484. The expected heterozyogosity ranged from 0.381 to 0.632. STRUCTURE analysis divided the 32 genotypes into three sub-populations. Subsequent phenotyping revealed that all the tolerant genotypes were grouped into one sub-population, whereas the moderately tolerant and susceptible genotypes were grouped into separate sub-populations. Phylogenetic tree constructed by the unweighted neighbour-joining method also divided the genotypes into three clusters. The grouping pattern of genotypes into the clusters was similar to that into the STRUCTURE analysis, on the basis of drought tolerance level. The average value of genetic dissimilarity coefficient among the genotypes was observed to be 0.486. Furthermore, by combining genotyping data with phenotyping data, 16 new donors for 6 qDTYs were identified.  相似文献   
96.
The Brassica vegetable crops are rich source of important antioxidant compounds having anticancer and health promoting properties. Development of F1 hybrids with better nutritional traits is one of the main breeding objectives in different vegetable crops. Our study is the first report of determining heterotic combinations utilizing cytoplasmic male sterile (CMS) and doubled haploid (DH) inbred lines for antioxidant compounds in snowball cauliflower. Twenty genetically diverse Ogura CMS lines of cauliflower and six DH male fertile inbred lines were crossed to develop 120 F1 hybrids in line?×?tester mating design. The resulting 120 test cross progenies along with 26 parents and 4 standard checks were evaluated in 10?×?15 alpha lattice design with three replications during next cropping season. The CMS lines Ogu33-1A, Ogu122-5A and Ogu119-1A were good general combiner and CMS line Ogu118-6A was poor general combiner for majority of traits. Most of the heterotic hybrids were associated with high positive SCA effects. The proportions of σ2A/D and \(\upsigma^{2}_{\text{gca}} /\upsigma^{2}_{\text{sca}}\) ratios were less than unity in all the cases indicating preponderance of non-additive gene action in the genetic control of all the traits. Highest number of heterotic hybrids with SCA effects in desired positive direction was recorded for ascorbic acid content and phenolic content followed by total carotenoid content. The F1 hybrids with better combining ability and better per se performance could be useful in accumulation of favourable allele for higher concentration of important anti-oxidant compounds.  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