全文获取类型
收费全文 | 425篇 |
免费 | 34篇 |
专业分类
林业 | 20篇 |
农学 | 4篇 |
55篇 | |
综合类 | 28篇 |
农作物 | 28篇 |
水产渔业 | 51篇 |
畜牧兽医 | 244篇 |
园艺 | 7篇 |
植物保护 | 22篇 |
出版年
2024年 | 1篇 |
2023年 | 2篇 |
2022年 | 9篇 |
2021年 | 14篇 |
2020年 | 18篇 |
2019年 | 34篇 |
2018年 | 20篇 |
2017年 | 26篇 |
2016年 | 20篇 |
2015年 | 15篇 |
2014年 | 15篇 |
2013年 | 30篇 |
2012年 | 29篇 |
2011年 | 35篇 |
2010年 | 13篇 |
2009年 | 21篇 |
2008年 | 6篇 |
2007年 | 22篇 |
2006年 | 15篇 |
2005年 | 10篇 |
2004年 | 9篇 |
2003年 | 8篇 |
2002年 | 7篇 |
2001年 | 8篇 |
2000年 | 6篇 |
1999年 | 5篇 |
1998年 | 6篇 |
1997年 | 12篇 |
1996年 | 11篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1992年 | 7篇 |
1991年 | 6篇 |
1990年 | 3篇 |
1989年 | 5篇 |
1988年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
排序方式: 共有459条查询结果,搜索用时 15 毫秒
381.
382.
Effect of Different Media and Protein Source on Equine Gametes: Potential Impact During In Vitro Fertilization
下载免费PDF全文
![点击此处可从《Reproduction in domestic animals》网站下载免费的PDF全文](/ch/ext_images/free.gif)
L González‐Fernández S Macedo JS Lopes A Rocha B Macías‐García 《Reproduction in domestic animals》2015,50(6):1039-1046
Equine in vitro fertilization (IVF) is still inconsistent. In the present work, we studied how modified Whitten's (MW) medium and Tissue Culture Medium 199 (TCM) added with Foetal Bovine Serum (FBS; 10% v/v) or Bovine Serum Albumin (BSA; 7 mg/ml) affected equine gametes to subsequently run IVF trials. Compact (Cp) and expanded (Ex) cumuli equine oocytes were matured and placed in TCM or MW supplemented with BSA or FBS for 18–20 h (no sperm added). In Ex oocytes, TCM‐199 added with FBS or BSA resulted in higher metaphase II (MII) rates (75.7% and 62.7%, respectively) than MW added with BSA (54%) or FBS (52.2%; p < 0.05); this was not observed for Cp oocytes. Equine sperm were capacitated in the same media at 10 × 106 sperm/ml for 4 h at 37°C; total motility and protein tyrosine phosphorylation (PY) were evaluated. While motility remained unchanged, TCM or MW added with FBS enhanced the number of sperm showing PY‐stained tails (25 ± 4.8% and 31 ± 6.6%; mean ± SEM, respectively) over BSA supplemented media (3 ± 1.2% and 11.7 ± 1.1%) for TCM and MW (p < 0.05). In view of the previous results, sperm were capacitated in TCM + FBS and MW + BSA (control); IVF trials were run in the same media supplemented with 200 ng/ml of progesterone, but no fertilization occurred. Our results show that TCM + FBS enhances Ex equine oocyte's meiotic competence over MW + BSA and TCM or MW added with FBS successfully induce equine PY over media supplemented with BSA. 相似文献
383.
da Silva Liebl Ariany Rabello Cáo Mirleide Araújo dos Santos Nascimento Marcelo Castro Philp Dalbert da Silva Duncan Wallice Luiz Paxiúba Pantoja-Lima Jackson Aride Paulo Henrique Rocha Bussons Márcia Regina Fragoso Machado Furuya Wilson Massamitu Faggio Caterina de Oliveira Adriano Teixeira 《Veterinary research communications》2022,46(1):9-25
Veterinary Research Communications - This study aimed to determine the dietary lysine requirements of juvenile Colossoma macropomum tambaqui based growth performance, hepatic and intestinal... 相似文献
384.
Ferraz AB Grivicich I von Poser GL Faria DH Kayser GB Schwartsmann G Henriques AT da Rocha AB 《Fitoterapia》2005,76(2):210-215
In the present study we have investigated the in vitro antitumor effects of three benzopyrans, 6-isobutyryl-5,7-dimethoxy-2,2-dimethylbenzopyran (1), 7-hydroxy-6-isobutyryl-5-methoxy-2,2-dimethylbenzopyran (2) and 5-hydroxy-6-isobutyryl-7-methoxy-2,2-dimethylbenzopyran (3) isolated from Hypericum polyanthemum. The three compounds tested demonstrated potent growth inhibitory activity at 40 microg/ml (<25% control growth) in the NCI-H460, HT-29 and U-373MG human cell lines. Determination of cell cycle distribution demonstrated that the antiproliferative effect of the three benzopyrans could be associated to alterations in the cell cycle phase distribution. Treatment with the IC50 of the three compounds induced an arrested in S phase. Only in cells treated with compound 3 did the percentage of sub-G1 population increase up to 9%, suggesting that this compound induced more cell death than the others. Consistent with sub-G1 analysis, appreciable oligonucleosomal DNA fragmentation was only observed in the NCI-H460 cell line treated with compound 3. From these results it can be suggested that despite no differences among the cytotoxicity of the three compounds, it was observed that the mechanism of their antiproliferative effects appears to be different. 相似文献
385.
da Silva Franco CC de Sant' Anna JR Rosada LJ Kaneshima EN Stangarlin JR De Castro-Prado MA 《Phytopathology》2011,101(8):923-928
Heterokaryosis is an important mechanism which provides genetic variability increase in filamentous fungi. In order to assess the diversity of vegetative compatibility reactions existing among Colletotrichum acutatum isolates derived from different hosts, complementary nit mutants of each isolate were obtained and paired in all possible combinations. Vegetative compatibility groups (VCG) were identified among the isolates according to their ability to form viable heterokaryons. Seven VCGs were identified among the isolates, one of which contained isolates from different hosts. VCGs 2 and 6 contained two and three members, respectively; VCG-3 contained four members, and four VCGs (1, 4, 5, and 7) contained a single one. This study shows, for the first time, the isolation and the parasexual segregation of a heterozygous diploid sector derived from the heterokaryon formed with nit mutants from VCG-6. Diploid, named DE-3, showed nit+ phenotype and growth rate similar to the parental wild isolate. When inoculated in the presence of the haploidizing agent benomyl, the diploid strain produced parasexual haploid segregants exhibiting the nit phenotypes of the crossed mutants. Since viable heterokaryons and diploid may be formed among vegetative compatible isolates of C. acutatum, this study suggests that the parasexual cycle may be an alternative source of genetic variability in C. acutatum isolates. 相似文献
386.
The present work aims at identifying the contribution of the different wine components to the foaming properties of wines. Twelve fractions were isolated from wine, and foam aptitude of each fraction was measured individually at the concentration at which it was recovered, using wine model solutions. For these concentrations, the maximum foam height (HM) was 8.4-11.7 cm, foam height on stability was 6.9-7.5 cm, and foam stability (TS) was 3.0-6.5 s. Moreover, foam measurements were also performed using 2-, 5-, and 10-fold concentrations of these compounds in wine. The HM increased linearly with the concentration of mannoproteins having low content of protein (MP1), and TS increased exponentially. The fractions that individually showed higher foaming properties were mixed in binary and ternary combinations, demonstrating that MP1 when mixed with low molecular weight hydrophobic compounds strengthens the air/water interface of these solutions, a characteristic that is on the basis of sparkling wines' foamability and foam stability. 相似文献
387.
José Alfredo Hernández-Ugalde Jorge Mora-Urpí Oscar J. Rocha 《Genetic Resources and Crop Evolution》2011,58(4):571-583
We studied the genetic relationship among four wild and ten cultivated populations of peach palm (Bactris gasipaes Kunth) using five microsatellite markers. Peach palm populations were grouped into two major complexes based on morphological
traits (see Mora-Urpí 1984, 1993): the Occidental group, including populations found north and west of the Andes Mountains, and the Oriental group, including
populations in the Amazon Basin. The Oriental group is further divided into two subgroups, the upper and eastern Amazonia.
We also studied two wild relatives of peach palm from the Maracaibo basin in Venezuela. All microsatellite loci were polymorphic
and the total number of alleles across all loci was 64. The number of alleles observed per locus ranged from 9 (Bg51) to 16
(Bg63; Average = 12.8 ± 2.8 alleles per locus), while the average number of alleles per population was 31.8 ± 7.3. Our data
also revealed that some alleles were common to populations from the same geographical region. A dendrogram based on Rogers
and Tanimoto’s similarity coefficient revealed three main branches. The first branch is divided into two nodes and includes
all populations from Occidental and Upper Amazonia groups; the second branch includes both populations from Eastern Amazonia,
and the third branch includes both wild relatives from Maracaibo. All populations included in each node are neighbors within
a geographic region, indicating that populations were finely clustered into their respective geographic groups. We propose
that this clustering supports the hypothesis of several independent domestication events on both sides of the Andes, as proposed
by Mora-Urpí (1993). 相似文献
388.
389.
390.