全文获取类型
收费全文 | 317篇 |
免费 | 30篇 |
国内免费 | 61篇 |
专业分类
林业 | 14篇 |
农学 | 12篇 |
基础科学 | 20篇 |
51篇 | |
综合类 | 86篇 |
农作物 | 10篇 |
水产渔业 | 31篇 |
畜牧兽医 | 97篇 |
园艺 | 80篇 |
植物保护 | 7篇 |
出版年
2024年 | 2篇 |
2023年 | 2篇 |
2022年 | 18篇 |
2021年 | 9篇 |
2020年 | 5篇 |
2019年 | 15篇 |
2018年 | 13篇 |
2017年 | 19篇 |
2016年 | 20篇 |
2015年 | 18篇 |
2014年 | 12篇 |
2013年 | 15篇 |
2012年 | 26篇 |
2011年 | 28篇 |
2010年 | 12篇 |
2009年 | 7篇 |
2008年 | 19篇 |
2007年 | 23篇 |
2006年 | 11篇 |
2005年 | 11篇 |
2004年 | 31篇 |
2003年 | 16篇 |
2002年 | 7篇 |
2001年 | 14篇 |
2000年 | 8篇 |
1999年 | 5篇 |
1998年 | 2篇 |
1997年 | 9篇 |
1996年 | 3篇 |
1995年 | 6篇 |
1994年 | 3篇 |
1993年 | 8篇 |
1992年 | 2篇 |
1990年 | 8篇 |
1983年 | 1篇 |
排序方式: 共有408条查询结果,搜索用时 31 毫秒
91.
CHU Zhong-hua MIN Jun LING Yun-biao ZHAO Hai-yan LIU Jian-ping OU Qing-jia 《园艺学报》2004,20(9):1672-1676
AIM: To investigate the expression of adhesion molecules in hepatocellular carcinoma (HCC), and analyze its clinical significance. METHODS: The expressions of adhesion molecules of tumor tissues of 64 cases and adjacent tissues of 12 cases of HCC were detected with RT-PCR. RESULTS: ①The expression rates of E-cadherin, ICAM-1, CD44, CD44V, α5, β1 were 90.62%, 93.75%, 50.00%, 96.88%, 100%, 100%, respectively, and there was a significant difference between CD44 and other adhesion molecules. ②The expression level of E-cadherin, ICAM-1, CD44, CD44V, α5,β1 in liver cancer tissues were 1.24±0.54, 0.96±0.37, 0.62±0.73, 0.86±0.33, 0.97±0.49, 1.41±0.24, respectively, and there was a significant difference between CD44 and E-cadherin, β1. ③The expression level of E-cadherin and CD44 mRNA declined as HCC stage become higher, and there was a statistical difference in the expression level of CD44 mRNA between Ⅰ-Ⅱ stage and Ⅳ stage. The expression level of ICAM-1, α5, β1 had a trend to rise as HCC stage become higher, and there was a statistical difference in the expression level of ICAM-1 between Ⅰ-Ⅱ stage and Ⅳ stage. ④The expression level of ICAM-1,CD44V, α5, β1 had positive correlation with tumor volume, tumor nodules, tumor metastasis, and had negative correlation with tumor encapsulation. E-cadherin and CD44 had negative correlation with tumor volume, tumor nodules, tumor metastasis, and had positive correlation with tumor encapsulation. All showed no significant correlation with the level of AFP , the degree of cirrhosis and the function of liver. CONCLUSION: There was a significant difference in the expression level of adhesion molecule mRNA in HCC, and their expression had Spearman correlation with each other. The expression level of adhesion molecule mRNA is associated with tumor volume, tumor nodules and tumor metastasis. 相似文献
92.
AIM: To explore the effects of Angelicae sinensis preparation and sodium ferulate on inflammatory liver injury induced by lipopolysaccharide (LPS) and their molecule mechanism. METHODS: ICR mice were divided into five groups: Angelicae sinensis group, sodium ferulate group, dexamethasone group, inflammation control group and normal group. The model of inflammatory injury in mice was set up by tail vein injection with the bacillus calmette-guerin (BCG) and LPS respectively prior and posterior to administration of those tested drugs. The tested drugs (the preparations of Angelica sinensis, sodium ferulate and dexamethasone) and normal saline were given respectively to the corresponding group. The pathological observation of the liver tissues in mice was made for the intensity of inflammatory liver injuries. The immunohistochemical detection and comparison were performed for the expression of ICAM-1 and E-selectin proteins in the liver tissues in those mice. RESULTS: The intensities of liver inflammatory injuries in mice from drug-treated groups were obviously lighter than that from the inflammation control group (P<0.01). The expressions of ICAM-1 and E-selectin proteins in the liver tissues of mice from the inflammation control group were not only significantly higher than that in normal control, but also obviously higher than that from drug-treated groups (P<0.01). CONCLUSIONS: Angelica sinensis and sodium ferulate alleviate inflammatory liver injury induced by injection of LPS. Their suppressive effects on inflammatory liver injury may be associated with the decrease in the expression of ICAM-1 and E-selectin proteins. 相似文献
93.
DAISUKE HASEGAWA NAOKO YAYOSHI YUKIHIRO FUJITA MICHIO FUJITA HIROMITSU ORIMA 《Veterinary radiology & ultrasound》2005,46(6):452-457
The criteria for brain atrophy in dogs have not yet been established, because of wide variation in the morphology of the ventricles and sulci of the brain depending on the breed and size. In this study, we examined the thickness of the interthalamic adhesion in a transverse magnetic resonance image to investigate normal, to examine the correlation with age, body weight, and breed, and to assess whether measurement would be a useful indicator of brain atrophy. The animals used in this study were of various breeds and weight, and had no identifiable intracranial lesion. They were divided into two groups: a normal group (0.6-15-year-old, n = 66) and a demented aging group (12-18-year-old, n = 12). The interthalamic adhesion thickness in both T1- and T2-weighted transverse images were measured in all dogs. The interthalamic adhesion thickness in the normal and demented groups was 6.79 +/- 0.70 and 3.82 +/- 0.79 mm, respectively. The interthalamic adhesion thickness in the demented group was significantly smaller. In an analysis of the correlation of interthalamic adhesion thickness with age and weight in normal dogs, significant negative and positive correlation was recognized, respectively. However, the strength of these correlations was low. These results suggest that interthalamic adhesion thickness may be a good parameter for evaluating brain atrophy in dogs with cognitive dysfunction. 相似文献
94.
AIM:To study the mechanisms of nicotine-induced expression of intercellular adhesion molecule-1(ICAM-1).METHODS:Related luciferase reporter gene plasmids were constructed with molecular cloning techniques;above plasmids and intracontrol plasmid pSV-β-gal were co-transfected into human umbilical vein endothelial cells(HUVECs) with eukaryotic gene transfection techniques; the relative luciferase activities were detected in the transfected HUVECs.RESULTS:Series of luciferase reporter gene containing different sequences of human ICAM-1 promotor and site-directed mutants of NF-κB and Sp-1 in promotor were successfully constructed; Nicotine could increase the expression of luciferase reporter gene plasmid containing-579 bp(pGL3E-579/+36),-230 bp(pGL3E-230/+36) and mutated Sp-1 version(pGL3E-Sp-1-MU)(P<0.05 vs control) of ICAM-1 promotor in the transfected HUVECs, whereas deletion derivative (pGL3E-134/+36) and mutation (pGL3E- NF-κB -MU) of downstream NF-κB site of ICAM-1 promotor prevent nicotine-induced increase in expression of luciferase reporter gene plasmid.CONCLUSION:NF-κB site of promotor mediates nicotine-induced ICAM-1 expression in human umbilical vein endothelial cells. 相似文献
95.
96.
97.
98.
用SF-1型外附力、内聚力测定仪测定了中国南方水田土壤对钢的粘附力。为探讨粘附力与机械组成和含水量的关系,将粘粒含量、含水量和粘附力划分为三个水平,以33种土样的有关数据为基础导出了土壤的粘附力与粘粒含量和含水量的模糊关系,并提出了一种用模糊推理法预测土壤对钢的粘附力的方法。 相似文献
99.
Lixing Huang Lina Guo Xiaojin Xu Yingxue Qin Lingmin Zhao Yongquan Su Qingpi Yan 《Journal of fish diseases》2019,42(5):703-712
Vibrio alginolyticus is a leading aquatic pathogen, causing huge losses to aquaculture. rpoS has been proven to play a variety of important roles in stress response and virulence in several bacteria. In our previous study, upon treatment with Cu2+, Pb2+, Hg2+ and low pH, the expression levels of rpoS were downregulated as assessed by RNA‐seq, while impaired adhesion ability was observed, indicating that rpoS might play roles in the regulation of adhesion. In the present study, the RNAi technology was used to knockdown rpoS in V. alginolyticus. In comparison with wild‐type V. alginolyticus, RNAi‐treated bacteria showed significantly impaired abilities of adhesion, growth, haemolytic, biofilm production, movement and virulence. Meanwhile, alterations of temperature, salinity, pH and starvation starkly affected rpoS expression. The present data suggested that rpoS is a critical regulator of virulence in V. alginolyticus; in addition, rpoS regulates bacterial adhesion in response to temperature, pH and nutrient content changes. These are helpful to explore its pathogenic mechanism and provide reference for disease control. 相似文献
100.
采用尼罗罗非鱼上皮细胞培养模型,观察嗜水气单胞菌对鳃上皮、皮肤上皮、肠上皮细胞的粘附率,研究载铜蒙脱石对细菌粘附的阻断作用及其对细菌粘附引起鱼上皮细胞膜生物特性变化的影响。结果显示:嗜水气单胞菌与鱼上皮细胞均有不同程度的粘附作用,粘附率大小顺序为鳃上皮〉皮肤上皮〉肠上皮细胞。载铜蒙脱石均显著降低了嗜水气单胞菌对鳃、皮肤和肠上皮细胞的粘附率(P〈0.05),而且对不同上皮细胞的粘附阻断率无显著差异。嗜水气单胞菌粘附肠上皮细胞后细胞膜生物特性发生了显著变化,与正常对照组相比,嗜水气单胞菌粘附鱼上皮细胞后,胞浆游离钙和细胞膜磷脂酶A2活性显著上升。载铜蒙脱石可显著降低由于嗜水气单胞菌粘附鱼上皮细胞引起的胞浆游离钙和细胞膜磷脂酶A2活性的升高。结果表明,载铜蒙脱石可有效阻断病原菌粘附,从而防治细菌感染和细菌移位。 相似文献