全文获取类型
收费全文 | 46478篇 |
免费 | 4094篇 |
国内免费 | 22篇 |
专业分类
50594篇 |
出版年
2023年 | 308篇 |
2022年 | 620篇 |
2021年 | 1307篇 |
2020年 | 818篇 |
2019年 | 980篇 |
2018年 | 1228篇 |
2017年 | 1001篇 |
2016年 | 1561篇 |
2015年 | 2409篇 |
2014年 | 2680篇 |
2013年 | 2882篇 |
2012年 | 3951篇 |
2011年 | 3619篇 |
2010年 | 2311篇 |
2009年 | 1997篇 |
2008年 | 2798篇 |
2007年 | 2740篇 |
2006年 | 2487篇 |
2005年 | 2239篇 |
2004年 | 2082篇 |
2003年 | 1949篇 |
2002年 | 1800篇 |
2001年 | 491篇 |
2000年 | 387篇 |
1999年 | 459篇 |
1998年 | 473篇 |
1997年 | 326篇 |
1996年 | 293篇 |
1995年 | 245篇 |
1994年 | 251篇 |
1993年 | 251篇 |
1992年 | 268篇 |
1991年 | 239篇 |
1990年 | 208篇 |
1989年 | 213篇 |
1988年 | 195篇 |
1987年 | 182篇 |
1986年 | 138篇 |
1985年 | 149篇 |
1984年 | 190篇 |
1983年 | 147篇 |
1982年 | 172篇 |
1981年 | 154篇 |
1980年 | 139篇 |
1979年 | 112篇 |
1978年 | 120篇 |
1977年 | 103篇 |
1976年 | 87篇 |
1974年 | 83篇 |
1973年 | 89篇 |
排序方式: 共有10000条查询结果,搜索用时 72 毫秒
61.
62.
E. A. Santos R. Keller 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1993,163(5):374-379
The effects of glutamate, aspartate, glycine, proline, alanine, taurine, glycerol, glucose and lactate injections on the haemolymph levels of the crustancean hyperglycemic hormone and/or glucose and lactate in the shore crab, Carcinus maenas, were investigated. Only glucose and lactate caused significant changes of hyperglycaemic hormone levels. Glucose injections resulted in a drop of both hormone and lactate, while lactate had an opposite effect, i.e. it raised both crustacean hormone and glucose levels. The results suggest that during increases in glycolytic flux, lactate may cause a release of hormone by a positive feedback mechanism. The hormone would then stimulate glycogenolysis, thus increasing glucose availability. If more glucose is released than is metabolized, excess glucose may leak from the cells and suppress crustancean hyperglycemic hormone release from the X-organ/sinus gland complex by negative feedback.Abbreviations ABTS
2,2-azino-bis (3-ethylbenzthiazoline sulphonic acid)
- ANOVA
one-way analysis of variance
- BSA
bovine serum albumin
- BW
body weight
- CHH
crustacean hyperglycemic hormone
- ELISA
cnzyme-liked immunosorbent assay
- GIH
gonadinhibiting hormone
- IgG
immunoglobin G
- MIH
moult-inhibiting hormone
- MTGXO
medulla terminalis X-organ
- PB
sodium phosphate buffer
- PBS
phosphate buffered saline
- Pi
inorganic phosphate
- XO-SG
X-organ-sinus gland complex 相似文献
63.
Patrice Daniel Erwin de Waele Jean-Noël Hallet 《Applied microbiology and biotechnology》1993,38(5):638-641
Genomic DNA of several strains oof oenological lactic bacteria belonging to the species Lactobacillus plantarum, Leuconostoc oenos and Pediococcus pentosaceus was digested by the rare-cutting endonucleases ApaI and SmaI. The restriction products were separated by transverse alternating field electrophoresis (TAFE). The size of the genome of L. oenos estimated by adding the molecular size of the ApaI fragments was on average 1320 kb. A strong polymorphism was observed between the strains, which could be easily differentiated except for two industrial strains of L. oenos. A simple modification of the TAFE apparatus is proposed to improve the separation of the DNA fragments.
Correspondence to: J.-N. Hallet 相似文献
64.
65.
Simple electromyographic biofeedback treatment for chronic pediatric constipation/encopresis: Preliminary report 总被引:2,自引:0,他引:2
Daniel J. Cox James Sutphen Stephen Borowitz Margie N. Dickens Janice Singles William E. Whitehead 《Applied psychophysiology and biofeedback》1994,19(1):41-50
Pediatric constipation/encopresis is thought to be due, in part, to paradoxical constriction of the external anal sphincter (EAS) muscle during attempted defecation. This inappropriate contraction can lead to delayed, impacted, painful, and infrequent bowel movements. Standard Medical Care (SMC) involves disimpaction with enemas, followed by laxative therapy and diet modification, to maintain frequent soft stools. Using the case control method, the efficacy of SMC alone was compared with SMC plus EAS electromyographic biofeedback aimed at eliminating paradoxical contraction. Thirteen consecutive chronically constipated children received SMC plus biofeedback, and were compared with 13 age- and sex-matched children who received only SMC. Biofeedback subjects demonstrated post-treatment elimination of EAS paradoxical constriction. At 16 months follow-up parents of biofeedback children reported significantly greater improvement in constipation, encopresis, laxative use, and painful bowel movements compared to SMC.This research report was supported by the NIH under grant No. RO1 HD 28160. 相似文献
66.
67.
Coelho-Rocha Nina Dias de Jesus Luís Cláudio Lima Barroso Fernanda Alvarenga Lima da Silva Tales Fernando Ferreira Enio Gonçalves José Eduardo dos Santos Martins Flaviano de Oliveira Carvalho Rodrigo Dias Barh Debmalya Azevedo Vasco Ariston de Carvalho 《Probiotics and antimicrobial proteins》2023,15(1):160-174
Probiotics and Antimicrobial Proteins - Beneficial effects of Lactiplantibacillus plantarum strains have been widely reported. Knowing that the effects of probiotic bacteria are strain-dependent,... 相似文献
68.
A systematic investigation of the genus Sphaeroplea was conducted using cladistic analyses of both structural and isozyme characters for the same set of taxa. The structural data were not able to fully resolve some of the taxa while the isozyme data did produce a tree in which all nodes were supported by data. The structural characters were relatively consistent with one another, whereas the isozyme characters were much less internally consistent. Results from independent, cladistic analyses of both data sets support the concept that among those Sphaeroplea species investigated, S. fragilis Buchheim et Hoffman had an early divergence. The two data sets differed primarily in that the structural data support monophyly of the genus Sphaeroplea and the isozyme data do not. The greater relative consistency of the structural data suggests better support for trees inferred from its analysis. Furthermore, searches for character congruence between the two data sets revealed isozyme data which support monophyly of the genus Sphaeroplea, but had been overwhelmed by conflicting isozyme characters. 相似文献
69.
70.