全文获取类型
收费全文 | 10029篇 |
免费 | 822篇 |
国内免费 | 5篇 |
出版年
2022年 | 47篇 |
2021年 | 98篇 |
2020年 | 56篇 |
2019年 | 82篇 |
2018年 | 120篇 |
2017年 | 111篇 |
2016年 | 155篇 |
2015年 | 230篇 |
2014年 | 288篇 |
2013年 | 538篇 |
2012年 | 482篇 |
2011年 | 488篇 |
2010年 | 294篇 |
2009年 | 290篇 |
2008年 | 469篇 |
2007年 | 498篇 |
2006年 | 456篇 |
2005年 | 490篇 |
2004年 | 447篇 |
2003年 | 440篇 |
2002年 | 430篇 |
2001年 | 337篇 |
2000年 | 380篇 |
1999年 | 347篇 |
1998年 | 126篇 |
1997年 | 105篇 |
1996年 | 104篇 |
1995年 | 105篇 |
1994年 | 91篇 |
1993年 | 115篇 |
1992年 | 279篇 |
1991年 | 192篇 |
1990年 | 205篇 |
1989年 | 204篇 |
1988年 | 306篇 |
1987年 | 180篇 |
1986年 | 154篇 |
1985年 | 135篇 |
1984年 | 104篇 |
1983年 | 93篇 |
1982年 | 60篇 |
1981年 | 62篇 |
1979年 | 80篇 |
1978年 | 60篇 |
1977年 | 38篇 |
1976年 | 43篇 |
1975年 | 45篇 |
1974年 | 57篇 |
1973年 | 44篇 |
1972年 | 49篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
111.
112.
Shin-Ichi Hayama Rika Akamatsu Mayumi Kishimoto Masatsugu Suzuki Hideo Nigi 《Primates; journal of primatology》1988,29(3):423-426
Diverticular disease of the colon was detected in a female Japanese monkey by X-ray examination. The monkey was 15 years old
and had been kept under captive conditions for nine years. Lack of appetite and activity, and constipation were observed.
The monkey was given fiber-rich vegetables and wild plants, and its appetite and activity then improved. Based on a consideration
of various factors, it is suggested that one possible cause of the diverticulosis in this case was a low dietary fiber intake. 相似文献
113.
Peter O''Connell G. Mark Lathrop Mark Leppert Yusuke Nakamura Ulrich Müller Jean-Marc Lalouel Ray White 《Genomics》1988,3(4):367-372
We have constructed a primary genetic map of human chromosome 18 consisting of 11 DNA markers and one serological marker (JK). Two of these loci define highly polymorphic VNTR systems. The markers define a continuous genetic linkage map of 97 cM in males and 205 cM in females; female genetic distances in a panel of 59 three-generation families were consistently about twice those observed in males. The high odds in support of the linear order of the markers on this recombination map, and the extent of coverage of chromosome 18, indicate that this map will permit efficient linkage studies of human genetic diseases that may be segregating on chromosome 18 and will provide anchor points for development of high-resolution maps for this chromosome. 相似文献
114.
115.
116.
Tomohiko Suzuki Akio Nakamura Yoshiaki Satoh Chisato Inai Takahiro Furukohri Tomikazu Arita 《Journal of Protein Chemistry》1992,11(6):629-633
The blood clamBarbatia virescens has a heterodimeric hemoglobin in erythrocytes. Interestingly, the congeneric clamsB. reeveana andB. lima contain quite different hemoglobins: tetramer and polymeric hemoglobin consisting of unusual didomain chain. The complete amino acid sequence of chain I ofB. virescens has been determined. The sequence was mainly determined from CNBr peptides and their subpeptides, and the alignment of the peptides was confirmed by sequencing of PCR-amplified cDNA forB. virescens chain I. The cDNA-derived amino acid sequence matched completely with the sequence proposed from protein sequencing.B. virescens chain I is composed of 156 amino acid residues, and the molecular mass was calculated to be 18,387 D, including a heme group. The sequence ofB. virescens chain I showed 35–42% sequence identity with those of the related clamAnadara trapezia and the congeneric clamB. reeveana. An evolutionary tree forAnadara andBarbatia chains clearly indicates that all of the chains are evolved from one ancestral globin gene, and that the divergence of chains has occurred in each clam after the speciation. The evolutionary rate for clam hemoglobins was estimated to be about four times faster than that of vertebrate hemoglobin. We suggest that blood clam hemoglobin is a physiologically less important molecule when compared with vertebrate hemoglobins, and so it evolved rapidly and resulted in a remarkable diversity in quaternary and subunit structure within a relatively short period. 相似文献
117.
118.
Structural and functional features of cis-acting sequences in the basic replicon of plasmid ColIb-P9. 下载免费PDF全文
K Tanaka H Sakai Y Honda T Nakamura A Higashi T Komano 《Nucleic acids research》1992,20(11):2705-2710
We have structurally and functionally analyzed the cis-elements essential for ColIb-P9 plasmid DNA replication. The putative oriV region encompassed a region of 172 base pairs (bp) located 152 bp downstream of the repZ gene. A typical dnaA box found in this region proved nonessential for the DNA replication of ColIb-P9. The ssi signal of ColIb-P9 is a homologue of the G-sites of R1 and R100 plasmids. Deletion of the G-site led to 1.5-fold reduction of the copy number, suggesting that although this G-site is not essential, it is important for efficient ColIb-P9 DNA replication. In addition, the ColIb-P9 replicon is highly and extensively homologous with the P307 (RepFIC) replicon, and highly homologous with the R100 (RepFIIA) replicon around the G-site region. These facts imply a common ancestry from which the plasmids have evolved. 相似文献
119.
Sylviane Olschwang Richard Fabre Pierre Laurent-Puig Anne Vassal Bernard Hamelin Yusuke Nakamura Gilles Thomas 《Human genetics》1992,88(6):658-660
Summary The EF5.44 locus is in close proximity to the chromosome 5 region to which the genetic defect responsible for familial adenomatous polyposis has been mapped. We have devised two oligonucleotides that promote the specific polymerase chain reaction (PCR) amplificiation of a 365-bp sequence in this region. Analysis by denaturing gradient gel electrophoresis of the resulting fragment has unravelled individual differences that could be identified as a single base pair change in aMnlI restriction site. This PCR assayable polymorphism increases the informativeness at this locus, and should be useful in the presymptomatic diagnosis of familial adenomatous polyposis. 相似文献
120.
Complete nucleotide sequence of the mitochondrial DNA from a liverwort,Marchantia polymorpha 总被引:1,自引:1,他引:0
Kenji Oda Katsuyuki Yamato Eiji Ohta Yasukazu Nakamura Miho Takemura Naoko Nozato Kinya Akashi Takeshi Kanegae Yutaka Ogura Takayuki Kohchi Kanji Ohyama 《Plant Molecular Biology Reporter》1992,10(2):105-163
Libraries of cosmid and plasmid clones covering the entire region of mtDNA from the liverwortMarchantia polymorpha were constructed. These clones were used for the determination of the complete nucleotide sequence of the liverwort mtDNA
totally 186,608 bp (GenBank no. M68929) and including genes for 3 species of ribosomal RNAs, 29 genes for 27 species of transfer
RNAs, and 30 genes for functionally known proteins (16 ribosomal proteins, 3 subunits of cytochromec oxidase, apocytochromeb protein, 3 subunits of H+-ATPase, and 7 subunits of NADH ubiquinone oxidoreductase). The genome also contains 32 unidentified open reading frames.
Thus the complete nucleotide sequences from both chloroplast and mitochondrial genomes have been determined in the same organism.
Plasmid clones are available upon the request.
Gene names are represented according to Lonsdale and Leaver (1988) with modifications recommended by Lonsdale (personal communication). 相似文献