全文获取类型
收费全文 | 5797篇 |
免费 | 325篇 |
国内免费 | 2篇 |
专业分类
6124篇 |
出版年
2023年 | 12篇 |
2022年 | 35篇 |
2021年 | 73篇 |
2020年 | 49篇 |
2019年 | 61篇 |
2018年 | 96篇 |
2017年 | 81篇 |
2016年 | 131篇 |
2015年 | 192篇 |
2014年 | 220篇 |
2013年 | 372篇 |
2012年 | 390篇 |
2011年 | 406篇 |
2010年 | 262篇 |
2009年 | 253篇 |
2008年 | 394篇 |
2007年 | 409篇 |
2006年 | 357篇 |
2005年 | 344篇 |
2004年 | 350篇 |
2003年 | 334篇 |
2002年 | 292篇 |
2001年 | 72篇 |
2000年 | 61篇 |
1999年 | 79篇 |
1998年 | 64篇 |
1997年 | 66篇 |
1996年 | 49篇 |
1995年 | 66篇 |
1994年 | 46篇 |
1993年 | 50篇 |
1992年 | 35篇 |
1991年 | 27篇 |
1990年 | 43篇 |
1989年 | 30篇 |
1988年 | 33篇 |
1987年 | 23篇 |
1986年 | 34篇 |
1985年 | 29篇 |
1984年 | 32篇 |
1983年 | 26篇 |
1982年 | 25篇 |
1981年 | 33篇 |
1980年 | 14篇 |
1979年 | 10篇 |
1978年 | 8篇 |
1977年 | 8篇 |
1976年 | 7篇 |
1975年 | 6篇 |
1965年 | 6篇 |
排序方式: 共有6124条查询结果,搜索用时 15 毫秒
1.
Y Tsujimoto K Nagashima M Yamazaki S Furuyama 《The International journal of biochemistry》1988,20(6):591-594
1. Formation of peroxides by benxoyl peroxide (BPO) and CuCl2 was examined in the human red blood cell ghost. 2. Amounts of peroxides formed increased with the amount of the ghost solution added. 3. Of all the cations tested only manganese ion inhibited the formation of peroxides in BPO-CuCl2 reaction system. 4. The formation of peroxides was inhibited approx. 50% with 0.4 microM manganese. 5. The inhibitory manner of manganese was non-competitive against copper. 相似文献
2.
3.
Hoshino Atsushi; Abe Yukihide; Saito Norio; Inagaki Yoshishige; Iida Shigeru 《Plant & cell physiology》1997,38(8):970-974
The Japanese morning glory carrying the recessive mutable speckledallele with the dominant speckled-activator bears colorlessflowers with fine and round colored spots distributed over thecorolla whereas the plant without the speckled-activator producespale yellow flowers. Previous chemical analysis has indicatedthat a mutation in the gene for flavanone 3-hydroxylase (F3H)is a likely candidate for the speckled allele. However, theF3HmRNA without sequence alteration accumulates normally inthe pale yellow flowers, indicating that the speckled alleleis neither the F3H gene nor a regulatory gene acting on theF3H gene expression. (Received April 4, 1997; Accepted June 2, 1997) 相似文献
4.
Toshiyuki Hamaoka Yasuyuki Takai Atsushi Kosugi Yumiko Mizushima Junko Shima Tsuneo Kusama Hiromi Fujiwara 《Cancer immunology, immunotherapy : CII》1985,20(3):183-188
Summary A new haptenic compound, a muramyl dipeptide (MDP) derivative (designated as L4-MDP-ONB) cross-reactive with Bacillus Calmette Guerin (BCG) was synthesized. The cross-reactivity of L4-MDP hapten to BCG was demonstrated from the following evidence; (a) lymph node cells from BCG-primed C3H/HeN mice exhibited appreciable L4-MDP-specific proliferative responses to the in vitro stimulation of L4-MDP-modified syngeneic cells (L4-MDP-self); (b) inoculation of L4-MDP-self into footpads of BCG-primed C3H/HeN mice elicited ample delayed type-hypersensitivity (DTH) responses in vivo as measured by footpad swelling; and (c) BCG-primed mice contained L4-MDP-reactive helper T cell activity which functions to augment the generation of effector T cell responses to cell surface antigens. This crossreactivity between L4-MDP hapten and BCG as measured by the helper T cell activity was applied to enhanced induction of tumor-specific immunity. When BCG-primed C3H/HeN mice were immunized with L4-MDP-modified syngeneic X5563 tumor cells, these mice could generate augmented tumor-specific in vivo protective (tumor neutralizing) immunity as well as in vitro cytotoxic T cell responses. These results indicate the effectiveness of L4-MDP hapten in augmenting tumor-specific immunity. The present approach is discussed in the context of potential advantages of this new hapten for its future application to clinical tumor systems. 相似文献
5.
Yohei Hashimoto Hiroyuki Ishizone Midori Moriyasu Kazuko Kawanishi Atsushi Kato Masaru Ogura 《Phytochemistry》1984,23(8):1807-1808
Three oleanane triterpenes were isolated from the roots of Periandra dulcis,and identified as 3β-hydroxy-25-al-olean-18-en-30-oic acid (periandric acid I), 3β-hydroxy-25-al-olean-12-en-30-oic acid (periandric acid II) and 3-oxo-25-hydroxy-olean-12-en-30-oic acid. The former two compounds (periandric acids I and II) were identical with the aglycones obtained by hydrolysis of periandrin I and II, respectively and the latter one was a new triterpene. 相似文献
6.
Tokuo Ogawa Junichi Sugenoya Norikazu Ohnishi Keiko Natsume Kazuno Imai Yoshikazu Kandori Akira Ishizuka Atsushi Osada 《European journal of applied physiology and occupational physiology》1993,67(4):354-359
We have examined the nonparallel changes in tampanic membrane temperatures (T
ty) from the two ears in response to various changes in body and head positions. Upon assuming a lateral recumbent position, the T
ty on the lower side increased while that on the upper side decreased. Pressure application over a wide area of the lateral chest only caused inconsistent and obscure asymmetric changes in T
ty. A lateral flexion of the head with the subject sitting upright and a rotation of the head to the side in a supine position induced an increase in the T
ty on the lower side compared to that on the upper side. The temperature and blood flow of the forehead often decreased on the lower side and increased on the upper side, although such responses were not always concomitant with the asymmetric changes in T
ty. A dorsal flexion of the head with the subject in a reclining position caused a slight increase in the T
ty, whereas raising the head upright induced a slight decrease in them. Two additional experiments were carried out with single photon emission computed tomography using 99mTc-hexamethylpropyleneamine oxime as tracer, and a slight, relative decrease in counts was noted in the right hemisphere during rotation of the head to the right. These results would strongly suggest that unilateral increases and decreases in T
ty could have been caused by one-sided decreases and increases, respectively, in blood flow to the brain and/or the tympanic membrane, induced by a vasomotor reflex involving vestibular stimulation. 相似文献
7.
8.
Yoshikazu Kuroki Ichiro Matsui Yoshifumi Yamamoto Atsushi Ieshima 《Human genetics》1980,55(2):227-229
Summary Disomic and trisomic cells of a patient with Down syndrome mosaic were used to study the effect of the additional chromosome 21 against an identical genetic background. The frequency of Ag staining and the participation in satellite associations were determined for each pair of acrocentric chromosomes. The additional chromosome 21 of the trisomic cells and its homologues proved to be regularly Ag positive. Therefore the trisomic cells showed more Ag positive chromosomes and more satellite associations per cell than the diploid cells. Thus, no compensation for the additional rRNA-gene dose could be found in the cells of the trisomic line. 相似文献
9.
10.
Tokuyuki Yoshida Kunihiko Morihiro Yuki Naito Atsushi Mikami Yuuya Kasahara Takao Inoue Satoshi Obika 《Nucleic acids research》2022,50(13):7224
Currently, gapmer antisense oligonucleotide (ASO) therapeutics are under clinical development for the treatment of various diseases, including previously intractable human disorders; however, they have the potential to induce hepatotoxicity. Although several groups have reported the reduced hepatotoxicity of gapmer ASOs following chemical modifications of sugar residues or internucleotide linkages, only few studies have described nucleobase modifications to reduce hepatotoxicity. In this study, we introduced single or multiple combinations of 17 nucleobase derivatives, including four novel derivatives, into hepatotoxic locked nucleic acid gapmer ASOs and examined their effects on hepatotoxicity. The results demonstrated successful identification of chemical modifications that strongly reduced the hepatotoxicity of gapmer ASOs. This approach expands the ability to design gapmer ASOs with optimal therapeutic profiles. 相似文献