全文获取类型
收费全文 | 14730篇 |
免费 | 834篇 |
国内免费 | 1330篇 |
专业分类
林业 | 864篇 |
农学 | 1361篇 |
基础科学 | 133篇 |
745篇 | |
综合类 | 4858篇 |
农作物 | 1183篇 |
水产渔业 | 568篇 |
畜牧兽医 | 3724篇 |
园艺 | 2648篇 |
植物保护 | 810篇 |
出版年
2024年 | 52篇 |
2023年 | 213篇 |
2022年 | 450篇 |
2021年 | 554篇 |
2020年 | 595篇 |
2019年 | 718篇 |
2018年 | 527篇 |
2017年 | 659篇 |
2016年 | 902篇 |
2015年 | 842篇 |
2014年 | 891篇 |
2013年 | 850篇 |
2012年 | 1128篇 |
2011年 | 1216篇 |
2010年 | 973篇 |
2009年 | 949篇 |
2008年 | 873篇 |
2007年 | 968篇 |
2006年 | 716篇 |
2005年 | 624篇 |
2004年 | 424篇 |
2003年 | 351篇 |
2002年 | 225篇 |
2001年 | 191篇 |
2000年 | 191篇 |
1999年 | 140篇 |
1998年 | 103篇 |
1997年 | 89篇 |
1996年 | 81篇 |
1995年 | 49篇 |
1994年 | 49篇 |
1993年 | 53篇 |
1992年 | 29篇 |
1991年 | 27篇 |
1990年 | 19篇 |
1989年 | 28篇 |
1988年 | 21篇 |
1987年 | 18篇 |
1986年 | 20篇 |
1985年 | 12篇 |
1984年 | 8篇 |
1983年 | 4篇 |
1982年 | 3篇 |
1981年 | 17篇 |
1980年 | 7篇 |
1977年 | 2篇 |
1976年 | 4篇 |
1962年 | 6篇 |
1956年 | 12篇 |
1955年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
11.
12.
13.
14.
15.
采用在体试验方法研究单羧酸转运蛋白第1亚型(monocarboxylate transporter 1,MCT1)抑制剂(p-chloromercuribenzene sulfonate,p-CMB)对乙酰胆碱(acetylcholine,Ach)诱导的大鼠胰液分泌的影响。Spra-gue-Dwley(SD)雄性大鼠,体重180g-210g,分6组,每组5只,试验前禁食24h,自由饮水。动物麻醉后经外科手术后,每隔10min收集一次胰液,采用Lowry法测定胰液蛋白量,Bernfeld法测定胰酶。结果对照组(-p-CMB)和实验组(+p-CMB),在注射1、5、10μg/kg的Ach后对胰液分泌量、胰蛋白分泌量以及胰淀粉酶分泌量都呈现增加作用,注射后1h内达到峰值,之后逐渐降低。然而,试验组的胰液分泌各项指标比对照组的显著减少(P〈0.01)。表明MCT1抑制剂p-CMB减弱了Ach增加大鼠胰液分泌的作用。 相似文献
16.
慢病毒可以感染分裂细胞和非分裂细胞,是较有前途的病毒载体,来源于HIV-1型载体,能阻止形成有复制能力的HIV-1病毒,构建一个更为安全的模式是慢病毒载体构建策略的焦点。该文介绍了慢病毒载体应用过程中的不同载体系统及构建策略,对载体的生物安全性进行了分析,展望了慢病毒在基因治疗、RNA干扰及转基因领域的应用前景。 相似文献
17.
湘椒6号是由湖南地方良种伏地尖中选出的自交系F81-1-2从北方引进的甜椒品种经6代单株选择而成L24-1自交系配制而成的一代杂各。该品种植株生长势强,耐寒、耐湿,果实粗牛角形,果色深绿,微辣,商品性好。从定值致收获35 ̄45天,667m^2产鲜椒3000kg。田间表现抗病毒病、疮痂病。 相似文献
18.
AIM: To investigate the effects of oxidized high-density lipoprotein (oxHDL) on membrane fluidity and the expression of lymphocyte function associated antigen(LFA-1) of monocyte. METHODS: The membrane fluidity of THP-1 cells was assayed by fluorescence anisotropy with DPH (1,6-dipheny-1,3,5-hexatriene), a fluorescent probe; The LFA-1 expression on THP-1 cells were assayed by flow cytometry with indirect immunofluorescence.RESULTS: The membrane fluidity of THP-1 cells was reduced by 45% and 52% respectively (P<0.01) after incubation with 100 μg protein/mL oxHDL and oxLDL for 20 h; oxHDL could stimulated the expression of LFA-1 on THP-1 cells, the positive cell rate and mean fluoresence intensity (MFI) increased by 39% and 45% respectively versus control group (P<0.01) after incubation with cells for 24 h. CONCLUSIONS: By increasing the expression of LFA-1 on monocyte, oxHDL can promote the monocyte-endothelium adhesion; oxHDL also can reduce the membrane fluidity of monocyte, that will limit the returning of monocytes from subendothelium back to the circulation. This suggested that oxHDL may play an important role in atherogenesis. 相似文献
19.
YAN Xiao-cheng MU Wei-na QIANG Ye ZHAO Hui-chen SUN Qi YAO Xiao-min ZHANG Yu-chao LIU Yuan-tao 《园艺学报》2000,36(9):1661-1666
AIM To investigate the effects of cytochrome P450 (CYP450) epoxygenase/epoxyeicosatrienoic acid (EET) pathway on insulin resistance in obese mice, and to explore the possible mechanisms. METHODS High-fat diet-induced obesity model was established in C57BL/6Cnc mice, and the obese mice were randomly divided into 3 groups, including obesity group (treated with saline; n =10), EET group (treated with 11,12-EET; n =10) and EET inhibitor 14,15-epoxyeicosa-5(Z)-enoic acid (EEZE) group (n =10). Normal C57BL/6Cnc mice (n =10) treated with saline served as control. Protein expression of CYP2J2 (one of CYP450 epoxygenases) and hypoxia-inducible factor-1α (HIF-1α) was measured by Western blot. Vessel-like structure was detected by immunofluorescence staining. The serum levels of insulin, tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6 and monocyte chemoattractant protein-1 (MCP-1) were measured by ELISA. RESULTS In obese mice, homeostasis model assessment of insulin resistance (HOMA-IR) values were increased, the protein level of CYP2J2 was reduced, and the protein level of HIF-1α was increased in adipose tissues as compared with the controls (P <0.05). The serum levels of MCP-1, IL-1β, IL-6 and TNF-α were also significantly increased in obese mice (P <0.05). After treatment with 11, 12-EET, the HOMA-IR values were decreased compared with vehicle-treated obese mice, HIF-1α expression levels were decreased in the adipose tissue, and the serum levels of MCP-1, IL-1β, IL-6 and TNF-α were reduced (P <0.05). Immunohistochemical results of adipose tissue from vehicle-treated obese mice showed a marked decrease in vessel-like structures (CD31-positive) compared with normal control mice (P <0.05). EET treatment significantly increased the newly formed vessel-like structures in the visceral adipose tissues of obese mice as compared with vehicle-treated obese mice (P <0.05). CONCLUSION High-fat diet-induced obesity and insulin resistance are closely related to the CYP450 pathway. Exogenous EETs effectively decrease obesity-induced insulin resistance possibly through pro-angiogenesis and attenuation of hypoxia and inflammation. 相似文献
20.
GUAN Cang-hai ZHAO Yu-qiao Guo Liang CHEN Yu-Zhu WANG Wei-Na JIANG Xing-ming 《园艺学报》2000,36(10):1908-1912
MNX1 antisense RNA 1 (MNX1-AS1) is a newly discovered long non-coding RNA (lncRNA), which is highly dysregulated in various carcinomas and its expression level is closely related to the overall survival and prognosis of patients. MNX1-AS1 regulates the occurrence and development of carcinomas by endogenous competitive adsorption of miRNA, regulating cell cycle, inducing epithelial mesenchymal transformation and activating multiple signaling pathways. The in-depth study of the carcinogenesis of MNX1-AS1 is useful for the early diagnosis, targeted therapy and prognostic assessment of relevant carcinomas. This article reviews the roles of MNX1-AS1 in malignant tumor. 相似文献