全文获取类型
收费全文 | 748篇 |
免费 | 19篇 |
国内免费 | 9篇 |
出版年
2021年 | 7篇 |
2018年 | 7篇 |
2017年 | 12篇 |
2016年 | 8篇 |
2015年 | 8篇 |
2014年 | 11篇 |
2013年 | 15篇 |
2012年 | 17篇 |
2011年 | 21篇 |
2010年 | 13篇 |
2009年 | 20篇 |
2008年 | 33篇 |
2007年 | 26篇 |
2006年 | 27篇 |
2005年 | 9篇 |
2004年 | 21篇 |
2003年 | 14篇 |
2002年 | 12篇 |
2001年 | 17篇 |
2000年 | 17篇 |
1999年 | 21篇 |
1998年 | 8篇 |
1996年 | 11篇 |
1992年 | 11篇 |
1991年 | 9篇 |
1990年 | 9篇 |
1989年 | 17篇 |
1988年 | 20篇 |
1987年 | 7篇 |
1986年 | 10篇 |
1985年 | 7篇 |
1983年 | 11篇 |
1979年 | 10篇 |
1978年 | 13篇 |
1977年 | 8篇 |
1974年 | 11篇 |
1973年 | 10篇 |
1972年 | 6篇 |
1970年 | 7篇 |
1968年 | 7篇 |
1959年 | 7篇 |
1958年 | 23篇 |
1957年 | 26篇 |
1956年 | 26篇 |
1955年 | 22篇 |
1954年 | 22篇 |
1953年 | 13篇 |
1952年 | 13篇 |
1951年 | 10篇 |
1950年 | 9篇 |
排序方式: 共有776条查询结果,搜索用时 15 毫秒
71.
72.
Dmitrieva LI Stepanian IE Perfil'ev AV Shemetun ON Romanov RG 《Vestnik rentgenologii i radiologii》2000,(3):8-16
The authors studied the pattern of X-ray changes detectable in the lungs of 41 patients with LCH. The results of classical X-ray study were supplemented by the data of computed tomography, ultrasonography, and 99mTc and 67Ga citrate radioisotopic studies. The diagnostic values of these techniques were compared. X-ray syndromes of changes in the lung in LCH were found to be interstitial, interstitial and granulomatous, tumorous (focal). The authors emphasize the multisystematic character of a lesion, the phasic nature and progression of the disease into fibrosis. 相似文献
73.
Dmitrieva NA Molchan OK Komissarov AA Sokolov VB Aksinenko AIu Pushin AN Chekhlov AN Debabov VG 《Bioorganicheskaia khimiia》1998,24(12):920-925
5,5-Bis(hydroxymethyl)-2-oxo-[1-(2-trifluoromethyl)-3,3,3- trifluoropropionamido)-1-trifluoromethyl-2,2,2-trifluoroethyl- 1,3,2-dioxaphosphan (CA-423) is an in vitro inhibitor of the Escherichia coli uridine and thymidine phosphorylases. Unlike widely studied nucleoside analogues, this compound binds to the enzymes irreversibly. Its LD50 in mice was 40 mg/kg. Due to the involvement of pyrimidine phosphorylases in carcinogenesis and the relatively low toxicity of CA-423, it is promising for anticancer therapy. 相似文献
74.
The mitochondrial DNA (mtDNA) of individuals from 79 colonies of Apis mellifera from five Canary Islands was studied using the Dra I test based on the restriction of PCR products of the tRNAleu–COII intergenic region. Five haplotypes of the African (A) lineage and one of the west European (C) lineage were found. The haplotypes A14 and A15 are described for the first time. These haplotypes have a new P sequence named P1 . The wide distribution and high frequency of haplotype A15 suggest that it is characteristic of the Canarian Archipelago. Sources of haplotype variability of honeybee mtDNA in the Canary Islands (waves of colonization from Africa, queen importations, habitat diversification) are discussed. 相似文献
75.
76.
77.
78.
Janaína A Couto Karina LA Saraiva Cleiton D Barros Daniel P Udrisar Christina A Peixoto Juliany SB César Vieira Maria C Lima Suely L Galdino Ivan R Pitta Maria I Wanderley 《Reproductive biology and endocrinology : RB&E》2010,8(1):13
Background
The present study was designed to examine the effect of chronic treatment with rosiglitazone - thiazolidinedione used in the treatment of type 2 diabetes mellitus for its insulin sensitizing effects - on the Leydig cell steroidogenic capacity and expression of the steroidogenic acute regulatory protein (StAR) and cholesterol side-chain cleavage enzyme (P450scc) in normal adult rats. 相似文献79.
S V Minenko N V Dmitrieva K L Chimishkian N V Zhukov E N Sokolova V B Larionova V V Ptushkin 《Antibiotiki i khimioterapii͡a》2002,47(7):13-19
Evaluation of benzylpenicillin (penicillin G) effect for infection prophylaxis at the oncological patients with severe postcytostatic neutropenia was performed. All the patients with neutrophils levels lower than 0.5 x 10(9)/L were recommended to use antibiotics for infection prophylaxis. Test-group (n = 40) used ciprofloxacin (0.5 g twice daily, per os) combined with benzylpenicillin (1.0 g four times daily, i/v); control group was treated by ciprofloxacin in the same dose only. Combination with benzylpenicillin resulted in statistically significant reduction of infections frequency among oncological patients. 相似文献
80.
R Gon?alves LA Szmuchrowski LS Prado BP Couto JCQ Machado VO Damasceno JA Lamounier 《Biology of sport / Institute of Sport》2015,32(3):255-260
The aim of this study was to assess the suitability of body mass index, waist circumference, waist-to-height ratio and aerobic fitness as predictors of cardiovascular risk factor clustering in children. A cross-sectional study was conducted with 290 school boys and girls from 6 to 10 years old, randomly selected. Blood was collected after a 12-hour fasting period. Blood pressure, waist circumference (WC), height and weight were evaluated according to international standards. Aerobic fitness (AF) was assessed by the 20-metre shuttle-run test. Clustering was considered when three of these factors were present: high systolic or diastolic blood pressure, high low-density lipoprotein (LDL) cholesterol, high triglycerides, high plasma glucose, high insulin concentrations and low high-density lipoprotein (HDL) cholesterol. A ROC curve identified the cut-off points of body mass index (BMI), WC, waist-to-height ratio (WHtR) and AF as predictors of risk factor clustering. BMI, WC and WHR resulted in significant areas under the ROC curves, which was not observed for AF. The anthropometric variables were good predictors of cardiovascular risk factor clustering in both sexes, whereas aerobic fitness should not be used to identify cardiovascular risk factor clustering in these children. 相似文献