全文获取类型
| 收费全文 | 314篇 |
| 免费 | 8篇 |
专业分类
| 林业 | 13篇 |
| 农学 | 7篇 |
| 基础科学 | 1篇 |
| 69篇 | |
| 综合类 | 37篇 |
| 农作物 | 27篇 |
| 水产渔业 | 87篇 |
| 畜牧兽医 | 60篇 |
| 园艺 | 2篇 |
| 植物保护 | 19篇 |
出版年
| 2025年 | 1篇 |
| 2024年 | 6篇 |
| 2023年 | 4篇 |
| 2022年 | 5篇 |
| 2021年 | 8篇 |
| 2020年 | 14篇 |
| 2019年 | 13篇 |
| 2018年 | 18篇 |
| 2017年 | 12篇 |
| 2016年 | 23篇 |
| 2015年 | 16篇 |
| 2014年 | 10篇 |
| 2013年 | 14篇 |
| 2012年 | 18篇 |
| 2011年 | 26篇 |
| 2010年 | 14篇 |
| 2009年 | 6篇 |
| 2008年 | 7篇 |
| 2007年 | 17篇 |
| 2006年 | 6篇 |
| 2005年 | 11篇 |
| 2004年 | 8篇 |
| 2003年 | 6篇 |
| 2002年 | 6篇 |
| 2001年 | 6篇 |
| 2000年 | 2篇 |
| 1999年 | 2篇 |
| 1997年 | 4篇 |
| 1996年 | 2篇 |
| 1995年 | 2篇 |
| 1994年 | 3篇 |
| 1993年 | 2篇 |
| 1992年 | 2篇 |
| 1991年 | 1篇 |
| 1990年 | 4篇 |
| 1989年 | 2篇 |
| 1988年 | 1篇 |
| 1987年 | 4篇 |
| 1986年 | 1篇 |
| 1985年 | 2篇 |
| 1984年 | 1篇 |
| 1983年 | 2篇 |
| 1982年 | 1篇 |
| 1980年 | 2篇 |
| 1978年 | 1篇 |
| 1977年 | 1篇 |
| 1965年 | 2篇 |
| 1964年 | 1篇 |
| 1963年 | 1篇 |
| 1956年 | 1篇 |
排序方式： 共有322条查询结果，搜索用时 0 毫秒
1.
2.
The red alga Kappaphycus alvarezii is economically important as an edible species and as a source of carrageenan, and has been extensively cultivated in many
tropical countries. For this species, different color strains, which differ from each another in growth rate and carrageenan
content, have been reported for decades. In this study, lectins from brown, red, and green strains of K. alvarezii cultivated in Vietnam were isolated and characterized for evaluation of their biochemical properties and contents. The results
showed that each color strain contained in common the three lectins, named KAA-1, KAA-2, and KAA-3, which shared the hapten-inhibition
profile of hemagglutination, 20 N-terminal amino acid sequence, and equivalent molecular mass within a range of 28,016 ± 1.2
to 28,021 ± 1.8 Da, but differed in their yields, with the highest yield of KAA-2. These properties of the three isolectins
were also comparable among the three different color strains. However, the sum of the yields of the three isolectins decreased
in the order: red (21.4 mg) to green (15.9 mg) to brown strains (15.1 mg), from 500 g fresh alga. Thus, this algal species
can be a good source of useful lectins, irrespective of color strain. 相似文献
3.
Monoclonal antibodies (MAbs) were prepared against avian reovirus S1133 protein sigmaA (esigmaA) synthesized in Escherichia coli. MAbs were characterized and used to develop a diagnostic test. Ten MAbs were selected for competitive binding assay following coupling with horseradish peroxidase. The results indicated that these MAbs delineated two epitopes I and II of esigmaA. An immuno-dot binding assay was used to detect the effect of denaturation on antibody recognition of the epitopes. All MAbs bound to esigmaA in its native form. After denaturation by boiling in SDS and 2-mercaptoethanol, the binding of MAbs recognizing epitope I was fully abolished. However, the reactivity of MAbs recognizing epitope II was not affected. MAbs 31 and 32, recognizing epitopes I and II, respectively, were selected for the cross-reactivity to heterologous reovirus strains. The results suggest that the two epitopes are highly conserved among these virus strains. A MAb capture enzyme-linked immunosorbent assay (ELISA) procedure was developed using MAbs 32 and 31 to detect reovirus protein sigmaA in samples from tendon tissues of infected bird and chicken embryo fibroblast (CEF) cell cultures. Avian reovirus sigmaA antigens in tendon specimens were detected from the inoculated birds as early as 2 days post-inoculation (PI), approximated a peak at 7 days PI, and maintained this until 16 days PI, then decreased gradually. A clear difference in absorbance values between the tendon samples of the avian reovirus- and mock-infected birds is obtained. Positive results were also obtained from avian reovirus-infected CEF and from the tendon tissues of naturally infected broilers. These results indicated that the MAb capture ELISA is a useful methods for the detection of avian reovirus from chickens suspected to have avian reovirus infections. 相似文献
4.
Min Zhang Dan Zheng Zhimei Peng Yuting Zhu Rongrong Li Qiong Wu Yan Li Hongyi Li Weihua Xu Mao Zhang Qichun Hung Yanfa Sun 《The Journal of Poultry Science》2021,58(2):131
In this study, signaling pathways and key differentially expressed genes (DEGs) involved in lipid metabolism in muscle and fat tissues were investigated. Muscle and abdominal fat tissues were obtained from 35-day-old female broilers for RNA sequencing. DEGs between muscle and fat tissues were identified. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses of DEGs were performed. A total of 6130 DEGs were identified to be significantly enriched in 365 GO terms, most of which were involved in biological processes, cellular components, and molecular functions in muscle and fat tissues. Three important lipid signaling pathways (pyruvate metabolism, the insulin signaling pathway, and the adipocytokine signaling pathway) were identified among the fat and muscle tissues of broilers. The key common DEGs in these pathways included phosphoenolpyruvate carboxykinase 2 (PCK2), acetyl-CoA carboxylase 1 alpha and beta (ACACA and ACACB), and the mitogen-activated protein kinase (AMPK) gene family. Hence, our findings revealed the pathways and key genes and gene families involved in the regulation of fat deposition in the muscle and fat tissues of broilers. 相似文献
5.
This study examined the effects of different extracts of adlay seed on the growth of human lung cancer cells in vitro and in vivo. The data showed that a methanolic extract, but not a water extract, of adlay seed exerted an antiproliferative effect on A549 lung cancer cells by inducing cell cycle arrest and apoptosis. It was also found that tumor growth in vivo was inhibited by the methanolic extract in a dose-dependent manner. The chemopreventive effect of adlay seed on the tobacco-specific carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-induced lung tumorigenesis in A/J mice was also investigated. Groups of mice were pre-fed with different diets, followed by feeding with NNK-containing drinking water for 8 months. The results indicated that feeding with diet containing 30% of powdered adlay seed reduced the number of surface lung tumors by approximately 50%. Taken together, these results indicate that the components of adlay seed exert an anticancer effect in vitro and in vivo and may be useful for the prevention of lung tumorigenesis. 相似文献
6.
Macrophage function is an important factor for resistance to infection and anti-oxidative vitamins and minerals can affect how macrophages function in fish. We report the in vivo effect of adding singular or combined vitamins (A, C, and E) and/or minerals (Se, Zn, Cu, Mn, and Fe) in diets on the immune system of tilapia (Oreochromis hybrids) peripheral blood monocyte-derived, anterior kidney-derived, and spleen-derived macrophages. An optimal dose of vitamins and/or minerals in diets increased macrophage proliferation and protective activity, maintained macrophage viability, increased body weight and length, and increased lysozyme activity, however, at improper doses and combinations of vitamins or minerals a decrease was observed. Furthermore, vitamins and/or minerals at any doses and combinations in diets decreased superoxide and nitric oxide production. Therefore, appropriate doses and combinations of vitamins and/or minerals in diets may increase tilapia macrophages immunity. 相似文献
7.
A. Gawlicka S. J. Teh S. S. O. Hung D. E. Hinton J. de la Noüe 《Fish physiology and biochemistry》1995,14(5):357-371
Ontogenetic changes in digestive tract histology and digestive enzyme histochemistry were investigated 11 to 36 days post-hatch in white sturgeon Acipenser transmontanus larvae. From initiation of exogenous feeding (12 days post-hatch), larvae were fed a commercial salmonid diet for the ensuing 24 days. The digestive system of white sturgeon displayed a high degree of morphologic organization and functionality at the onset of exogenous feeding. An enhancement of digestive capacities occurred with transition to active feeding. On day 2 of feeding, there was a clear increase of alkaline phosphatase, aminopeptidase M, dipeptidyl peptidase IV, and -glutamyl transpeptidase activity in the brush border of the spiral intestine. This strong activity is an apparent confirmation of the importance of this segment of the intestine for protein digestion and nutrient absorption. The functional development of the pyloric intestine occurred on day 4 and was concomitant with an increase in the activity of brush border and cytoplasmic enzymes such as acetylcholinesterase, dipeptidyl peptidase II, - and -galactosidases. The absence of acetylcholinesterase, lactase, nonspecific esterase, and weak activity of exopeptidases and alkaline phosphatase in the anterior intestine suggests that this segment of the intestine may be less important in nutrient absorption than the pyloric and spiral intestines. The observed quantitative and qualitative differences in enzyme activity along the intestine indicate a high degree of specialization of each segment for specific digestive and absorptive processes. 相似文献
8.
9.
10.
We assessed the effect of mycorrhizal inoculation on short‐term uptake kinetics of arsenate and arsenite by excised roots of upland rice (Oryza sativa L. cv. Zhonghan 221). A concentration of 0.01–0.05 mM arsenic (As) differentially affected the influx rates of both arsenate and arsenite into rice roots non‐inoculated or inoculated with Glomus mosseae and G. versiforme. While Vmax for arsenate uptake by non‐mycorrhizal roots was 1.02 µmol g?1 fresh weight h?1, it was reduced by a factor of 2.4 for mycorrhizal roots (about 0.42 µmol g?1 fresh weight h?1) in the high‐affinity uptake system. However, at high concentrations of 0.5–2.5 mM As only G. versiforme was able to reduce As influx. The results show that mycorrhizal effects on As uptake of upland rice are both concentration and species‐specific. 相似文献