全文获取类型
收费全文 | 247篇 |
免费 | 2篇 |
国内免费 | 1篇 |
专业分类
林业 | 21篇 |
农学 | 26篇 |
基础科学 | 1篇 |
54篇 | |
综合类 | 9篇 |
农作物 | 8篇 |
水产渔业 | 12篇 |
畜牧兽医 | 95篇 |
园艺 | 4篇 |
植物保护 | 20篇 |
出版年
2022年 | 2篇 |
2021年 | 13篇 |
2020年 | 3篇 |
2019年 | 1篇 |
2018年 | 4篇 |
2017年 | 1篇 |
2016年 | 3篇 |
2015年 | 12篇 |
2014年 | 9篇 |
2013年 | 26篇 |
2012年 | 20篇 |
2011年 | 12篇 |
2010年 | 9篇 |
2009年 | 8篇 |
2008年 | 13篇 |
2007年 | 17篇 |
2006年 | 13篇 |
2005年 | 12篇 |
2004年 | 14篇 |
2003年 | 18篇 |
2002年 | 17篇 |
2001年 | 7篇 |
2000年 | 4篇 |
1999年 | 2篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1992年 | 1篇 |
1989年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1971年 | 2篇 |
排序方式: 共有250条查询结果,搜索用时 15 毫秒
101.
102.
Takahashi M Une R Fukushima K Fujiki M Misumi K Miyoshi N Endo Y Ohishi A Akuzawa M 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2005,67(8):837-841
Two canine nm-23 cDNAs, designated as nm23-C1 and -C2, were isolated and characterized. Both have a putative open reading frame consisting of 459-bp encoding 152 amino acids and are highly similar to human, mouse and rat homologues. To understand the potential role of nm23-C1 and -C2 in the development of mammary gland tumors (MGT), we analyzed the mRNA expression in 14 MGT samples by RT-PCR. The samples were divided into categories according to their histopathology (benign/malignant) and metastasis. No significant difference in the mRNA expression levels of either nm23-C1 or -C2 were observed between the benign and malignant groups or the metastatic and non-metastatic groups. These results suggest that nm23-C1 and -C2 are not related to the establishment of malignancy and metastatic lesions in canine MGT cases. 相似文献
103.
Kashiwazaki N Yamaguchi R Uesugi R Hishiyama N Kim M Nakatsukasa E Kojima Y Okuda Y Hisamatsu S Inomata T Shino M 《The Journal of reproduction and development》2005,51(6):735-739
We examined motility, plasma membrane integrity, and binding capacity to homologous zona pellucidae (ZP) of frozen/thawed epididymal cat sperm as a model species for endangered felines. Epididymal spermatozoa from 20 domestic cats were frozen with freezing egg-yolk extender containing 3.0% glycerol in 0.25-ml straws. Post-thaw motility and plasma membrane integrity of the frozen/thawed spermatozoa were 31.8 +/- 2.4% and 32.2 +/- 4.2%, respectively. The frozen/thawed spermatozoa were co-cultured with frozen/thawed immature homologous oocytes with intact ZP for 3 h to examine their ability to bind to the ZP. Sixteen of the 20 frozen/thawed sperm samples demonstrated the ability to bind to ZP. These results indicated that the freezing system for epididymal sperm used in the present study gives appropriate information for banking the genetic resources of wild felid species. 相似文献
104.
105.
Kazutoshi?Saeki Masao?Sakai Takashi?KunitoEmail author 《Biology and Fertility of Soils》2012,48(4):469-474
Andosols and the soil components (allophanes, humic acids, and goethite) had been autoclaved to destroy the nuclease activity of soil microflora. DNA adsorption by allophanes and Andosols was decreased by increasing the amount of α-casein added to the allophanes and to soils up to casein concentration of 5 mg ml?1. DNA adsorption by humic acids was significantly increased by increasing the amount of α-casein up to 1.0 mg ml?1, whereas the addition of 20 mg α-casein ml?1 completely blocked DNA adsorption. These results can explain why the addition of excess skim milk is operationally needed for effective DNA extraction from Andosols. The amount of DNA adsorbed by Andosols treated with dephosphorylated α-casein was significantly higher than that of not treated Andosols (p?0.01), thus showing an opposite behavior than α-casein addition, implying that phosphate groups of the protein can contribute to the decrease in the DNA adsorption by soil components. These results explain that the usefulness of skim milk as an additive for the extraction of DNA from Andosols is due to the presence of phosphate groups and hydrophobic components of casein, the main constituent of skim milk. 相似文献
106.
Kaseda M Ichihara N Nishita T Amasaki H Asari M 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2006,68(2):131-135
In the present study, we firstly demonstrated immunohistochemical expressions of secretory carbonic anhydrase (CA-VI) isozyme in bovine forestomach, large intestine and major salivary glands. CA-VI was detected in basal layer epithelial cells of esophageal and forestomach stratified epithelium, in mucous cells of upper glandular region of large intestine, in serous acinar cells of the parotid gland, in serous demilune cells and some ductal liner cells of mandibular, monostomatic sublingual and esophageal glands. These immunohistolocalizations suggested that bovine CA-VI plays various roles in pH regulation, maintenance of ion and fluid balance, and cell proliferation. 相似文献
107.
Ichihara N Ishikawa T Kaseda M Nishita T Amasaki H Asari M 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2006,68(12):1363-1365
The immunolocalization of the efferent duct and the epididymis in canine was firstly examined using an the immunohistochemical method with the canine carbonic anhydrase (CA) -I, CA-II and CA-III antisera. The efferent duct was immunonegative for all present canine CA antisera. However, some slender shaped epithelial cells in the head and body segments of the epididymal duct were intensely reacted to the CA-II antiserum. These results suggested that the CA-II might be controlled in the luminal environment in the head and body segments of the canine epididymis by the proton and bicarbonate balance for the maintenance of the spermatozoal stability and movement. 相似文献
108.
Photodegradation of (14)C-labeled fenitrothion ([O,O-dimethyl O-(3-methyl-4-nitrophenyl) phosphorothioate]) and parathion ([O,O-diethyl O-(4-nitrophenyl) phosphorothioate]) was conducted on a series of solid surfaces including isolated tomato fruit and leaf cuticle waxes. The wax-coated glass plate gave the comparative degradation of fenitrothion observed for the intact plant but both surfaces of octadecyl-capped silica gel and poly(tetrafluoroethylene) enhanced its volatilization. Photoinduced desulfuration and ester cleavage were common to both pesticides in waxes, but formation of the azo derivative was found to be a major degradation pathway characteristic of parathion. The modified electronic states of the nitro group by introduction of m-methyl group accounted for this different photoreactivity based on molecular orbital calculations. 相似文献
109.
Ingested delphinidin-3-rutinoside is primarily excreted to urine as the intact form and to bile as the methylated form in rats 总被引:2,自引:0,他引:2
Matsumoto H Ichiyanagi T Iida H Ito K Tsuda T Hirayama M Konishi T 《Journal of agricultural and food chemistry》2006,54(2):578-582
Many reports have described the bioavailability of anthocyanins; however, most of these reports investigated only the amount of anthocyanins excreted in urine. In the present study, we calculated the pharmacokinetic bioavailability of anthocyanins in rats by measuring the plasma concentration of delphinidin-3-rutinoside that had been administered orally or intravenously. Delphinidin-3-rutinoside was primarily absorbed in the blood and excreted into urine as unmetabolized forms with a T(max) of 26.3 min and a C(max) of 0.285 +/- 0.071 micromol/L. We detected small amounts of the metabolite 4'-O-methyl-delphinidin-3-rutinoside in the plasma, but we detected neither anthocyanidin (aglycone) nor glucuro- or sulfoconjugates. For the 8 h period after intake, delphinidin-3-rutinoside and 4'-O-methyl-delphinidin-3-rutinoside were excreted to urine at 795 +/- 375 and 12.3 +/- 2.91 nmol, respectively. Relative to intravenous injection, oral administration of delphinidin-3-rutinoside resulted in complete bioavailability (0.49 +/- 0.06%). Analysis of delphinidin-3-rutinoside plasma concentrations in bile cannulated rats revealed that, for the 8-h period after intake, the intact delphinidin-3-rutinoside excretion ratio in bile was 11% of the excretion ratio of 4'-O-methyl-delphinidin-3-rutinoside, 1.91 +/- 0.35 nmol versus 17.4 +/- 8.67 nmol, respectively. Setting the bile duct cannulation in a Bollman-type cage, however, significantly increased the bioavailability of orally administered delphinidin-3-rutinoside (18.14 +/- 6.24%). This effect appears to stem immobilization stress by reducing gastrointestinal motility. The cumulative excretion of delphinidin-3-rutinoside and 4'-O-methyl-delphinidin-3-rutinoside in urine and bile was 2.67 +/- 1.24% (w/w) of the dose ingested. Studies report that several metabolites are formed after oral ingestion of anthocyanins. Examples include glucuronyl from cyanidin-3-glucoside and both glucuronyl and sulfate conjugates from pelargonidin-3-glucoside. Our results indicate that delphinidin-3-rutinoside might be metabolized differently from cyanidin-3-glucoside and pelargonidin-3-glucoside. 相似文献
110.
Sato M Sato H Ogawa A Nomura R Takashima S Bang HJ Matsuoka H Imaizumi K 《Journal of agricultural and food chemistry》2007,55(22):8967-8971
The consumption of isoflavone-containing foods such as soybean and soybean products has been reported to have beneficial effects on the cardiovascular system in postmenopausal women. The present study was carried out to examine the mechanism underlying the beneficial effects of isoflavones in apolipoprotein (apo) E-deficient mice subjected to ovarian resection. Compared with sham-operated mice, ovariectomized mice had a larger arterial lesion area in the aortic root. Feeding the ovariectomized mice an isoflavone-containing diet (0.055 mg/kJ of total isoflavones/cal of diet) reduced the size of these lesions more than did feeding them with an isoflavone-free diet. Neither ovariectomy nor diet had a significant effect on the concentration of cholesterol in serum and urinary levels of isoprostanes, which are biomarkers for oxidative stress in vivo. The ovariectomized mice showed a greater increase in mRNA abundance for monocyte chemoattractant protein (MCP)-I in the aorta and in the level of nitric oxide (NO) secreted by peritoneal macrophages in culture than did the sham-operated mice. The isoflavone-containing diet lowered the MCP-I expression and the NO secretion more than did the isoflavone-free diet. These results suggest that dietary isoflavones confer an antiatherogenic effect by preventing the activation of macrophages due to the removal of ovaries. 相似文献