全文获取类型
收费全文 | 1241篇 |
免费 | 55篇 |
出版年
2022年 | 8篇 |
2021年 | 4篇 |
2020年 | 6篇 |
2019年 | 5篇 |
2018年 | 5篇 |
2017年 | 13篇 |
2016年 | 11篇 |
2015年 | 33篇 |
2014年 | 33篇 |
2013年 | 60篇 |
2012年 | 58篇 |
2011年 | 84篇 |
2010年 | 53篇 |
2009年 | 52篇 |
2008年 | 99篇 |
2007年 | 95篇 |
2006年 | 95篇 |
2005年 | 118篇 |
2004年 | 108篇 |
2003年 | 88篇 |
2002年 | 61篇 |
2001年 | 12篇 |
2000年 | 8篇 |
1999年 | 9篇 |
1998年 | 10篇 |
1997年 | 12篇 |
1996年 | 10篇 |
1995年 | 7篇 |
1994年 | 10篇 |
1993年 | 12篇 |
1992年 | 8篇 |
1991年 | 9篇 |
1990年 | 5篇 |
1989年 | 11篇 |
1988年 | 8篇 |
1987年 | 6篇 |
1986年 | 7篇 |
1985年 | 10篇 |
1984年 | 7篇 |
1983年 | 6篇 |
1982年 | 5篇 |
1981年 | 5篇 |
1980年 | 2篇 |
1979年 | 6篇 |
1978年 | 4篇 |
1977年 | 5篇 |
1976年 | 5篇 |
1975年 | 3篇 |
1966年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有1296条查询结果,搜索用时 15 毫秒
1.
Genotoxicity of ptaquiloside, a bracken carcinogen, in the hepatocyte primary culture/DNA-repair test 总被引:2,自引:0,他引:2
The genotoxicity of ptaquiloside (PT), recently isolated from bracken fern and shown to be carcinogenic, was examined by means of the hepatocyte primary culture/DNA-repair test. PT elicited clear unscheduled DNA synthesis with a dose-response effect. The result indicates that PT is a genotoxic carcinogen. 相似文献
2.
3.
4.
The genotoxicity of a variety of aniline derivatives was examined by a DNA repair test with rat hepatocytes. Out of 37 aniline derivatives, 6 chemicals, i.e., 2,4,6-trimethylaniline (mesidine), 2,4-xylidine, 3,5-diaminobenzoic acid, 3,4-diaminochlorobenzene, 2-chloro-4-methylaniline and 4-chloro-N-methylaniline, elicited positive DNA repair responses. The results are in agreement with the bacterial mutagenicities with or without norharman of these compounds. Positive compounds of unknown carcinogenicity in the present assay, i.e., 3,5-diaminobenzoic acid, 2-chloro-4-methylaniline and 4-chloro-N-methylaniline are suspected of being potentially carcinogenic. 相似文献
5.
Shigeyuki Eguchi 《Culture, medicine and psychiatry》1991,15(4):421-451
Two cases of kitsune-tsuki (fox possession) in a mountain village are examined from psychiatric and ethnographic viewpoints. Kitsune-tsuki, one of the most familiar expressions of madness in Japan, represents, as an interactive performance, religious and mythopoetic contexts metaphorically in time of crises. The atypical symptoms and the complicated clinical process of these cases reflect a multistratified cultural background and its transformation; communal religion, folk tales, kyôgen play, shared concepts of illness, and the post-war rise of one religious cult. The psychiatric diagnosis, trying to arrive at a single correct understanding, partially translates the entangled indigenous illness. Focusing on these issues; the dichotomy between form and content of mental illness, the atypicality of the symptoms and the restructive process of illness experiences, the author reconsiders the possibility of interpretation, diagnosis and treatment which respect the multiple realities. 相似文献
6.
H Yamazaki Y Mori K Toyoshi H Mori S Sugie N Yoshimi Y Konishi 《Mutation research》1985,144(3):197-202
The genotoxicity of N-nitrosodipropylamine, 8 of its oxidized derivatives and N-nitroso-2,6-dimethylmorpholine was examined in the hepatocyte primary culture (HPC)/DNA repair test. Nine N-nitrosamines which are known to be carcinogenic and mutagenic were clearly positive in the HPC/DNA-repair test. N-Nitroso(2,3-dihydroxypropyl) (2-hydroxypropyl)amine did not elicit DNA repair, but showed a borderline mutagenic response in the Salmonella/microsome test. Thus, the HPC/DNA-repair test displays a comparable capacity to the bacterial mutagenesis test for detecting the genotoxic effects of this class of carcinogens. 相似文献
7.
Tajima Shigeyuki; Kanazawa Takeshi; Takeuchi Eiko; Yamamoto Yukio 《Plant & cell physiology》1985,26(5):787-795
The cadaverine content of soybean radicles showed a maximumpeak 34 days after planting. The variation coincidedwith radicle uricase activity during seed germination. The uricase activity could not be fractionate when the bufferpH for the extraction was at 6.0. The addition of 1 M KCl orNaCl to the buffer allowed the extraction of the uricase activity,but an addition of 1 M MgCl2 or BaCl2 inhibited this enzyme'sactivity. The urate-degrading enzyme system was purified 248-fold permilligram of protein from soybean radicles. The respective Kmvalues of the diamine oxidase activity for cadaverine and ofthe urate-degrading activity for hydrogen peroxide and uratewere 1.25, 2.93 and 50.3 µM. Analysis by gel electrophoresisof the partially purified enzyme fraction revealed that theurate-degrading enzyme system consisted of a peroxidase thatdegrades urate with hydrogen peroxide and a diamine oxidasethat releases hydrogen peroxide. These data are evidence that a urate-degrading diamine oxidaseand peroxidase system exists in soybean radicles and that thereaction rate of urate-degradation is controlled by the concentrationof cadaverine. (Received November 28, 1984; Accepted April 8, 1985) 相似文献
8.
Embryos at the morula, blastocyst and hatched blastocyst stage were obtained from superovulated and naturally ovulated Japanese native goats. They were bisected into halves with a glass needle, and transferred immediately or after culture (for morula) to recipients. None of five does which received bisected morula became pregnant. Three of nine goats became pregnant after transfer of bisected hatched blastocysts, six of eleven recipients became pregnant. Four of them produced monozygotic twins and the remaining two produced singles. The present study demonstrated that the hatched blastocyst is suitable for bisection in the goat. 相似文献
9.
Kimitaka Yakura Atsushi Kato Shigeyuki Tanifuji 《Molecular & general genetics : MGG》1984,193(3):400-405
Summary The DNA fragments including the whole large spacer region of Vicia faba rDNA were cloned in plasmid pBR325. Sixteen clones were classed into five groups which differed from each other in the lengths of the rDNA inserts. Physical maps of these length variants cloned were constructed using EcoRI, SalI, HpaI, MluI and AccI and evidence was obtained that the length heterogeneity was due mainly to the differing number of 325 base pairs (bp) subrepeating elements in the large spacer. Sequence analysis of this subrepeating element revealed that it consisted of a duplet of an approximately 155 bp sequence and a 14 bp unrelated sequence. This structure of the repetitive element is novel. 相似文献
10.
Dispersion capabilities of new queens were studied in the two haplometrotic paper wasps Polistes riparius and P. snelleni. New queens were marked on the nests in the late summer and located in the next spring. Dispersion distances greatly varied among queens: although a large part of recovered queens nested in close proximity to their natal sites, some did disperse over 100–300 m. This suggests that queens' emigration from and immigration into the censused areas occurred to a substantial extent. On the whole, these species exhibited a weaker “philopatric” tendency than those so far studied for dispersion distance, and seem to have the potential for a long-distance dispersion. 相似文献