全文获取类型
收费全文 | 1036篇 |
免费 | 76篇 |
国内免费 | 4篇 |
出版年
2021年 | 7篇 |
2020年 | 19篇 |
2019年 | 41篇 |
2018年 | 30篇 |
2017年 | 8篇 |
2016年 | 16篇 |
2015年 | 18篇 |
2014年 | 27篇 |
2013年 | 44篇 |
2012年 | 70篇 |
2011年 | 102篇 |
2010年 | 84篇 |
2009年 | 41篇 |
2008年 | 33篇 |
2007年 | 28篇 |
2006年 | 35篇 |
2005年 | 22篇 |
2004年 | 21篇 |
2003年 | 21篇 |
2002年 | 17篇 |
2001年 | 35篇 |
2000年 | 22篇 |
1999年 | 28篇 |
1998年 | 24篇 |
1997年 | 15篇 |
1996年 | 22篇 |
1995年 | 19篇 |
1994年 | 8篇 |
1993年 | 20篇 |
1992年 | 15篇 |
1991年 | 11篇 |
1990年 | 16篇 |
1989年 | 24篇 |
1988年 | 9篇 |
1987年 | 14篇 |
1986年 | 8篇 |
1985年 | 8篇 |
1984年 | 8篇 |
1983年 | 9篇 |
1981年 | 7篇 |
1980年 | 10篇 |
1979年 | 10篇 |
1978年 | 12篇 |
1977年 | 7篇 |
1976年 | 7篇 |
1975年 | 6篇 |
1974年 | 8篇 |
1973年 | 10篇 |
1971年 | 7篇 |
1970年 | 9篇 |
排序方式: 共有1116条查询结果,搜索用时 15 毫秒
1.
2.
3.
A case of chromomycosis in which hyperthermia proved effective is reported. The patient was a 56-year-old male bean curd maker who, without any previous history of minor trauma, developed on the extensor side of the left upper arm an eczematous lesion that underwent gradual radial expansion. The lesion showed a well-defined, 7×10 cm infiltrated erythematous plaque with the central area healed and, at the upper and lower borders, adherent scales and crusts on the surface. Histological examination revealed granulomatous changes in the dermis, as well as sclerotic cells within giant cells and microabscesses. On culturing,Fonsecaea pedrosoi was isolated. The patient was treated with disposable chemical pocket warmers, which were secured over the lesion with a rather tight elastic bandage, so that they kept the affected area warm for 24 hours a day. After a month of such hyperthermic treatment, the erythema and infiltration had decreased considerably, and microscopic examination and culture of the crusts both yielded negative results. Examination of biopsy specimens of the lesion after the third month showed that it had cicatrized. The treatment was stopped after 4 months, and no relapse occurred. We also summarize the published results of local hyperthermic treatment of chromomycosis in Japan. 相似文献
4.
5.
Margot S. Kruskall MD Elizabeth E. Eynon Zuheir Awdeh Chester A. Alper Edmond J. Yunis 《Immunogenetics》1987,26(4-5):216-219
The HLA class I antigen B44 is found in each of two different extended major histocompatibility haplotypes (allele combinations of HLA-B, HLA-DR, and complement genes BF, C2, C4A, and C4B in linkage disequilibrium). Using isoelectric focusing, two variants of HLA-B44 were identified. The basic variant was found in all cell lines with the extended haplotype HLA-B44, DR7, FC31, and the acidic variant in all cell lines with the extended haplotype HLA-B44, DR4, SC30. The occurrence of each antigen variant with a unique extended haplotype explains previous observations concerning the nonrandom association of B44 variants with DR antigens. 相似文献
6.
J N Chacon M R Chedekel E J Land T G Truscott 《Biochemical and biophysical research communications》1987,144(2):957-964
Various unstable intermediate oxidation states have been postulated in the metabolic activation of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine to the 1-methyl-4-phenyl pyridinium ion. We now report the first direct observation of these free radical intermediates by pulse radiolysis and flash photolysis. Studies are described of various reactions of such species, in particular with dopamine whose autoxidation to dopamine quinone is reported to be potentiated by 1-methyl-4-phenyl-1,2,3, 6-tetrahydropyridine. 相似文献
7.
Multistage carcinogenesis induced by ras and myc oncogenes in a reconstituted organ 总被引:22,自引:0,他引:22
ras and myc oncogenes were able to induce distinct phenotypic alterations, resembling different types of premalignant lesions, when introduced into approximately 0.1% of the cells used to reconstitute the mouse prostate gland. While ras induced dysplasia in combination with angiogenesis, myc induced a hyperplasia of the otherwise normally developed organ. ras and myc together induced primarily carcinomas. However, tumor progression was also associated with additional genetic alterations involving gene amplification. Our data indicate that specific types of benign premalignant lesions may reflect the activation of different single oncogenes, and that the consecutive activation of multiple oncogenes could be a causal event in the step-like progression of tumorigenesis. 相似文献
8.
9.
10.
Ras-mediated cell cycle arrest is altered by nuclear oncogenes to induce Schwann cell transformation. 总被引:21,自引:1,他引:20
下载免费PDF全文
![点击此处可从《The EMBO journal》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The cellular responses to ras and nuclear oncogenes were investigated in purified populations of rat Schwann cells. v-Ha-ras and SV40 large T cooperate to transform Schwann cells, inducing growth in soft agar and allowing proliferation in the absence of added mitogens. Expression of large T alone reduces their growth factor requirements but is insufficient to induce full transformation. In contrast, expression of v-Ha-ras leads to proliferation arrest in Schwann cells expressing a temperature-sensitive mutant of large T at the restrictive temperature. Cells arrest in either the G1 or G2/M phases of the cell cycle, and can re-enter cell division at the permissive temperature even after prolonged periods at the restrictive conditions. Oncogenic ras proteins also inhibit DNA synthesis when microinjected into Schwann cells. Adenovirus E1a and c-myc oncogenes behave similarly to SV40 large T. They cooperate with Ha-ras oncogenes to transform Schwann cells, and prevent ras-induced growth arrest. Thus nuclear oncogenes fundamentally alter the response of Schwann cells to a ras oncogene from cell cycle arrest to transformation. 相似文献