全文获取类型
收费全文 | 257篇 |
免费 | 13篇 |
出版年
2023年 | 1篇 |
2022年 | 2篇 |
2021年 | 5篇 |
2019年 | 1篇 |
2018年 | 2篇 |
2017年 | 6篇 |
2016年 | 6篇 |
2015年 | 8篇 |
2014年 | 8篇 |
2013年 | 25篇 |
2012年 | 11篇 |
2011年 | 14篇 |
2010年 | 8篇 |
2009年 | 8篇 |
2008年 | 17篇 |
2007年 | 8篇 |
2006年 | 18篇 |
2005年 | 17篇 |
2004年 | 7篇 |
2003年 | 18篇 |
2002年 | 15篇 |
2001年 | 2篇 |
2000年 | 4篇 |
1999年 | 8篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1988年 | 1篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 5篇 |
1981年 | 4篇 |
1980年 | 1篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1973年 | 2篇 |
排序方式: 共有270条查询结果,搜索用时 281 毫秒
1.
Masazumi Matsumura Shiro Kataoka Shuichi Aiba 《Molecular & general genetics : MGG》1986,204(2):355-258
Summary Amino acid residues of the carboxyl-terminal region of kanamycin nucleotidyltransferase were modified using segment-directed mutagenesis. Six different mutant enzymes with single amino acid replacements were selected out of 59 clones by DNA sequence analyses. The mutant enzymes were purified and it was found that the thermostability of one mutant enzyme was identical to the wild type, whereas the other five were less thermostable at varying degrees. The data suggested that changes in the enzyme thermostability depend not only on the position but also on the species of amino acid residue replaced. 相似文献
2.
Comparison of Three 18 F-Labeled Butyrophenone Neuroleptic Drugs in the Baboon Using Positron Emission Tomography 总被引:1,自引:0,他引:1
Carroll D. Arnett Chyng-Yann Shiue Alfred P. Wolf Joanna S. Fowler Jean Logan Masazumi Watanabe 《Journal of neurochemistry》1985,44(3):835-844
The butyrophenone neuroleptics spiroperidol, benperidol, and haloperidol were radiolabeled with fluorine-18 and studied in baboon brain using positron emission transaxial tomography (PETT). Pretreatment of the baboon with a high pharmacological dose of (+)-butaclamol reduced the specifically bound component of radioactivity distribution in the striatum to approximately the radioactivity distribution found in the cerebellum. Comparative studies of brain distribution kinetics over a 4-h period indicated that either [18F]spiroperidol or [18F]benperidol may be suitable for specific labeling of neuroleptic receptors. In an 8-h study with [18F]spiroperidol, striatal radioactivity did not decline, suggesting that spiroperidol either has a very slow dissociation rate or that it binds irreversibly to these receptors in vivo. [18F]Haloperidol may not be suitable for in vivo PETT studies, because of a relatively high component of nonspecific distribution and a faster dissociation from the receptor. Analysis of 18F in plasma after injection of [18F]spiroperidol indicated rapid metabolism to polar and acidic metabolites, with only 40% of the total radioactivity being present as unchanged drug after 30 min. Analysis of the metabolic stability of the radioactively labeled compound in rat striatum indicated that greater than 95% of [18F]spiroperidol remains unchanged after 4 h. 相似文献
3.
Satoshi Yoshida Masazumi Takeshita Akihiko Kawaguchi 《Biochemical and biophysical research communications》1984,124(2):322-328
The elongation of arachidoyl-CoA by swine cerebral microsomes resulted in the production of behenic acid (22:0) and lignoceric acid (24:0) concomitantly. When 4S-[4-2H1]NADPH was used for the elongation of arachidoyl-CoA, the incorporation of two deuterium atoms into 22:0 was observed by the technique of mass fragmentography. Furthermore, the incorporation of four deuterium atoms into 24:0 was also detected. On the other hand, when 4R-[4-2H1]NADPH was used, no deuterium was incorporated into the elongated products. 相似文献
4.
Masazumi Mitani 《Primates; journal of primatology》1986,27(4):397-412
Japanese monkeys often exchange the particular vocal sound, “coo,” especially when they feed or move as a group. It was considered
that the “coo” sound had no positive social meaning, perhaps because the “coo” sound network and its function were hidden
behind other behavioral observations. For identification of the vocalizer only from hearing the “coo” sound, three phonetic
values, i.e., the “fundamental,” “duration,” and “formants,” plus other characteristics were used as indices of voiceprints. The results indicated that these were effective for identifying
the vocalizer in two-thirds of the adults in the study troop which was composed of 12 adults and 16 immature members. The
“coo” sound exchange network among the troop members (adults) was drawn on the basis of the voiceprint identification. The
network showed three characteristics as follows: (1) matriarchs of the kin-groups frequently exchanged “coo” sounds with each
other; (2) the other females exchanged “coo” sounds mostly within their own kin-groups; and (3) males seldom participated
in the “coo” sound exchange. This suggests that “coo” sound exchange plays a central role for the matriarch of kin-groups
in binding each kin-group and, ultimately, in binding all members together into an organized troop. 相似文献
5.
Masazumi Mitani 《Primates; journal of primatology》1990,31(4):625-634
Brief results of a survey are reported for the primate fauna in south-eastern Cameroon and northern Congo. The survey was
carried over the period from October 1988 to January 1989. I confirmed the occurrence ofMandrillus sphinx in the south-eastern part of Cameroon, viz. the south bank of the Dja river, the occurrence ofCercocebus albigena in almost all the survey areas, the occurrence ofCercopithecus cephus, C. nictitans, C. pogonias, andGorilla g. gorilla throughout the areas, and the occurrence ofCercopithecus neglectus andColobus badius near Bomassa, 70 km north of Ouesso, in Congo. I also confirmedColobus polykomos satanas in some parts of Cameroon, but this species is declining. Local people provided information onCercocebus galeritus agilis, Colobus guereza, andPan troglodytes in almost all the areas, in some of which I confirmed the animals directly. They also provided information aboutCercocebus torquatus on the north bank of the Dja river in Cameroon andMiopithecus talapoin in Sembe in Congo, although I could not confirm these species myself. Human activities had begun reducing the populations
of the above primates, particularly those ofMandrillus sphinx, Colobus polykomos satanas, andGorilla g. gorilla, in south-eastern Cameroon and in northern Congo despite the low density of the human populations. 相似文献
6.
Y Suzuki H Suzuki T Kayama T Yoshimoto S Shibahara 《Biochemical and biophysical research communications》1991,181(3):955-961
Neurofibromatosis type 1 (NF1) is an autosomal dominant neurocutaneous disorder. A part of the gene for NF1 was cloned and its deduced protein has a domain functionally related to mammalian ras GTP-ase-activating protein (GAP). Human tissues examined express two types of NF1 mRNAs: an originally identified species of NF1 mRNA (type I) and another one containing the 63 base insert in the region coding for GAP-related domain (type II). However relative levels of both mRNAs seem to change under certain conditions. Human brain expresses type I mRNA predominantly, while type II is preferentially expressed in most primary brain tumors (13/16 tumors analyzed). We suggest that higher levels of type II mRNA may be related to the genesis of brain tumors. 相似文献
7.
8.
9.
Hatakeyama Wataru Lee Cliff Da Silva John Kim David M. Nagai Shigemi Kondo Hisatomo Nagai Masazumi 《International journal of peptide research and therapeutics》2021,27(2):957-965
International Journal of Peptide Research and Therapeutics - A DNA hybridization-based differential peptide display (DPD) was developed for the screening of phage peptide library to find osteogenic... 相似文献
10.
Kanao Kobayashi Ikue Hayashi Syuntaro Kouda Fuminori Kato Tamaki Fujiwara Shizuo Kayama Hideki Hirakawa Hideyuki Itaha Hiroki Ohge Naomasa Gotoh Tsuguru Usui Akio Matsubara Motoyuki Sugai 《PloS one》2013,8(8)
In a continuing study from Dec 2006 to Apr 2008, we characterized nine multi-drug resistant Pseudomonas aeruginosa strains isolated from four patients in a ward at the Hiroshima University Hospital, Japan. Pulsed-field gel electrophoresis of SpeI-digested genomic DNAs from the isolates suggested the clonal expansion of a single strain; however, only one strain, NK0009, was found to produce metallo-β-lactamase. PCR and subsequent sequencing analysis indicated NK0009 possessed a novel class 1 integron, designated as In124, that carries an array of four gene cassettes: a novel aminoglycoside (AG) resistance gene, aac(6′)-Iag, bla
IMP-1, a truncated form of bla
IMP-1, and a truncated form of aac(6′)-Iag. The aac(6′)-Iag encoded a 167-amino-acid protein that shows 40% identity with AAC(6′)-Iz. Recombinant AAC(6′)-Iag protein showed aminoglycoside 6′-N-acetyltransferase activity using thin-layer chromatography (TLC) and MS spectrometric analysis. Escherichia coli carrying aac(6′)-Iag showed resistance to amikacin, arbekacin, dibekacin, isepamicin, kanamycin, sisomicin, and tobramycin; but not to gentamicin. A conjugation experiment and subsequent Southern hybridization with the gene probes for bla
IMP-1 and aac(6′)-Ig strongly suggested In124 is on a conjugal plasmid. Transconjugants acquired resistance to gentamicin and were resistant to virtually all AGs, suggesting that the In124 conjugal plasmid also possesses a gene conferring resistance to gentamicin. 相似文献