全文获取类型
收费全文 | 755篇 |
免费 | 43篇 |
国内免费 | 36篇 |
专业分类
系统科学 | 4篇 |
丛书文集 | 19篇 |
教育与普及 | 16篇 |
理论与方法论 | 2篇 |
现状及发展 | 81篇 |
综合类 | 708篇 |
自然研究 | 4篇 |
出版年
2023年 | 12篇 |
2022年 | 16篇 |
2021年 | 17篇 |
2020年 | 13篇 |
2019年 | 13篇 |
2018年 | 12篇 |
2017年 | 14篇 |
2016年 | 20篇 |
2015年 | 31篇 |
2014年 | 45篇 |
2013年 | 19篇 |
2012年 | 30篇 |
2011年 | 41篇 |
2010年 | 25篇 |
2009年 | 36篇 |
2008年 | 43篇 |
2007年 | 52篇 |
2006年 | 36篇 |
2005年 | 52篇 |
2004年 | 47篇 |
2003年 | 36篇 |
2002年 | 44篇 |
2001年 | 26篇 |
2000年 | 19篇 |
1999年 | 14篇 |
1998年 | 18篇 |
1997年 | 5篇 |
1996年 | 11篇 |
1995年 | 9篇 |
1994年 | 13篇 |
1993年 | 16篇 |
1992年 | 15篇 |
1991年 | 4篇 |
1990年 | 6篇 |
1989年 | 10篇 |
1988年 | 7篇 |
1987年 | 1篇 |
1985年 | 5篇 |
1984年 | 1篇 |
排序方式: 共有834条查询结果,搜索用时 734 毫秒
191.
Clinical implications of p53 mutations 总被引:5,自引:0,他引:5
The ultimate goal of basic cancer research is to provide a theoretical foundation for rational approaches to improve cancer
therapy. Our extensive insight into the biology of the p53 tumour suppressor and the clinical behaviour of tumours harbouring
p53 mutations indicates that information concerning p53 will be useful in diagnosis and prognosis, and may ultimately produce
new therapeutic strategies. At the same time, efforts to understand the clinical implications of p53 mutations have revealed conceptual and technical limitations in translating basic biology to the clinic. The lessons learned
from p53 may lay the groundwork for future efforts to synthesize cancer gene function, cancer genetics and cancer therapy. 相似文献
192.
193.
Cytomegalovirus infection blocks apoptosis in cancer cells 总被引:8,自引:0,他引:8
Michaelis M Kotchetkov R Vogel JU Doerr HW Cinatl J 《Cellular and molecular life sciences : CMLS》2004,61(11):1307-1316
Recent pathological findings reveal a higher frequency of human cytomegalovirus (HCMV) in tumor cells from different tumors compared with surrounding tissues. Experimental investigations suggest possible supportive effects of HCMV for tumor development and progression. One HCMV effect on tumor cells is the inhibition of apoptosis, leading to the promotion of tumor cell survival. Decreased sensitivity to treatment-induced tumor cell death is a major reason for failure of anticancer chemotherapy. HCMV infection interferes with both the intrinsic and extrinsic cellular apoptosis pathways. HCMV promotes cell survival signaling influencing the tumor suppressor p53 and its relative p73, and stimulates the antiapoptotic Ras/Raf/MEK/Erk- and PI-3K-signaling pathways. Antiapoptotic effects mediated by HCMV are inhibited by antiviral treatment in cell culture. Therefore, a better understanding of the influence of HCMV infection on tumor cell apoptosis might translate into improved anti-cancer therapy.Received 10 November 2003; received after revision 22 December 2003; accepted 14 January 2004 相似文献
194.
Roblick UJ Hirschberg D Habermann JK Palmberg C Becker S Krüger S Gustafsson M Bruch HP Franzén B Ried T Bergmann T Auer G Jörnvall H 《Cellular and molecular life sciences : CMLS》2004,61(10):1246-1255
Changes in the proteome of colon mucosal cells accompany the transition from normal mucosa via adenoma and invasive cancer to metastatic disease. Samples from 15 patients with sporadic sigmoid cancers were analyzed. Proteins were separated by two-dimensional gel electrophoresis. Relative differences in expression levels between normal tissue, adenoma, carcinoma and metastasis were evaluated in both intra- and inter-patient comparisons. Up- and down-regulated proteins (<twofold) during development to cancer or metastasis were excised and submitted to peptide mass fingerprinting and MS/MS sequence analysis, facilitated by the use of a compact disc workstation. In total, 112 protein spots were found to be differentially regulated, of which 72 were determined as to protein identity, 46 being up-regulated toward the progression of cancer, and 26 down-regulated. Several of the identifications correlate with proteins of the cell cycle, cytoskeleton or metabolic pathways. The pattern changes now identified have the potential for design of marker panels for assistance in diagnostics and therapeutic strategies in colorectal cancer.Received 2 February 2004; received after revision 16 March 2004; accepted 18 March 2004 相似文献
195.
通过PCR-RFLP技术分析了Si-1基因的外显子在肿瘤样本与正常人群外周血液样本的突变情况,初步确定了Si-1基因的第15号外显子的第56位发生点突变,突变类型为C—T的置换突变,其编码的P(脯氨酸)变化为S(丝氨酸).在正常人群外周血液样本中的突变频率为14%,而在肿瘤中的突变频率为24.7%,尤其在肠癌中的突变频率高达51.5%.上述结果表明Si-1基因的外显子的突变与肿瘤间有一定关系. 相似文献
197.
农业外来有害生物入侵现状及防控对策 总被引:5,自引:0,他引:5
外来有害生物的入侵对农业生产安全、生态环境、人类健康和社会构成了严重影响.报道了我国目前外来有害生物入侵现状,并提出了防控对策. 相似文献
198.
Gimenez F Barraud de Lagerie S Fernandez C Pino P Mazier D 《Cellular and molecular life sciences : CMLS》2003,60(8):1623-1635
Physiologically in the brain, cytokines such as tumor necrosis factor-alpha (TN) are released by the immune system and can modulate neurological responses. Conversely, the central nervous system (CNS) is also able to modulate cytokine production. In the case of CNS disorders, cytokine release may be modified. Cerebral malaria (CM) is a complication of Plasmodium falciparum infection in humans and is characterized by a reversible encephalopathy with seizures and loss of consciousness. Central clinical signs are partly due to sequestration of parasitized red blood cells in the brain microvasculature due to interactions between parasite proteins and adhesion molecules. TNF is produced and released by host cells following exposure to various malarial antigens. The increase of TNF release is responsible for the overexpression of adhesion molecules. This article reviews the involvement of TNF in cerebral malaria and the relation with all the processes involved in this pathology. It shows that (i) TNF levels are increased in plasma and brain but with no clear correlation between TNF levels and occurrence and severity of CM; (ii) TNF is responsible for intercellular adhesion molecule-1 upregulation in CM, the relation being less clear for other adhesion molecules; (iii) TNF receptors are upregulated in CM, with TNF receptor 2 (TNFR2) showing a higher upregulation than TNFR1 in vivo; (iv) in murine CM, low doses of TNF seem to protect from CM, whereas excess TNF induces CM and anti-TNF therapies (antibodies, pentoxifylline) did not show any efficiency in protection from CM. Moreover, the involvement of lymphotoxin a, which shares with TNF the same receptors with similar affinity, appears to be an interesting target for further investigation.Received 4 December 2002; received after revision 7 February 2003; accepted 14 February 2003 相似文献
199.
钙调素拮抗剂对荷瘤小鼠主要器官钙调素(CaM)水平的影响 总被引:1,自引:1,他引:0
本文采用磷酸二酯酶(PDE)法,测定了小檗胺衍生物EBB对荷S180瘤小鼠的主要器官和瘤体CaM含量的影响。实验结果表明,EBB具有使荷瘤后小鼠脑、肺、肝、脾、肾五个主要器官CaM由不正常趋向正常的能力,而已知抗肿瘤药物丝裂霉素和环磷酰胺单独使用时此种能力较弱,但这两种抗肿瘤药物与EBB联合作用时,能使荷瘤鼠诸器官的CaM水平趋向正常。结果提示,专一性强的CaM拮抗剂在抑制肿瘤的同时可能还具有维护 相似文献
200.