全文获取类型
收费全文 | 1795篇 |
免费 | 93篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 151篇 |
妇产科学 | 17篇 |
基础医学 | 188篇 |
口腔科学 | 47篇 |
临床医学 | 160篇 |
内科学 | 392篇 |
皮肤病学 | 23篇 |
神经病学 | 143篇 |
特种医学 | 475篇 |
外科学 | 102篇 |
综合类 | 28篇 |
预防医学 | 47篇 |
眼科学 | 13篇 |
药学 | 62篇 |
中国医学 | 3篇 |
肿瘤学 | 58篇 |
出版年
2022年 | 4篇 |
2021年 | 7篇 |
2020年 | 9篇 |
2019年 | 7篇 |
2018年 | 16篇 |
2017年 | 10篇 |
2016年 | 23篇 |
2015年 | 27篇 |
2014年 | 26篇 |
2013年 | 68篇 |
2012年 | 29篇 |
2011年 | 29篇 |
2010年 | 73篇 |
2009年 | 59篇 |
2008年 | 35篇 |
2007年 | 27篇 |
2006年 | 38篇 |
2005年 | 24篇 |
2004年 | 20篇 |
2003年 | 22篇 |
2002年 | 27篇 |
2001年 | 21篇 |
2000年 | 32篇 |
1999年 | 34篇 |
1998年 | 134篇 |
1997年 | 118篇 |
1996年 | 124篇 |
1995年 | 92篇 |
1994年 | 74篇 |
1993年 | 83篇 |
1992年 | 26篇 |
1991年 | 29篇 |
1990年 | 20篇 |
1989年 | 63篇 |
1988年 | 48篇 |
1987年 | 51篇 |
1986年 | 50篇 |
1985年 | 56篇 |
1984年 | 33篇 |
1983年 | 42篇 |
1982年 | 35篇 |
1981年 | 21篇 |
1980年 | 37篇 |
1979年 | 20篇 |
1978年 | 16篇 |
1977年 | 18篇 |
1976年 | 23篇 |
1975年 | 24篇 |
1971年 | 2篇 |
1966年 | 2篇 |
排序方式: 共有1910条查询结果,搜索用时 15 毫秒
1.
A preliminary study comparing sleep restriction and relaxation treatments for insomnia in older adults 总被引:2,自引:0,他引:2
This study compared Sleep Restriction Therapy (SRT) and Relaxation Therapy (RLT) as treatments for insomnia in a sample of community-residing elderly (mean age, 69.7 years). SRT subjects (n = 10) and RLT subjects (n = 12) reported information about their sleep twice daily to a telephone recording machine for 2 weeks of baseline, 4 weeks of treatment, and 2 weeks at 3-month follow-up. Results showed sleep latency and waking after sleep onset were significantly reduced for both treatment groups under active treatment. Predictable reductions in time in bed and improved sleep efficiency reported during active treatment by SRT subjects were still apparent at 3-month follow-up; no corresponding changes were found for RLT. In both groups, increased total sleep time was reported at follow-up; the improvement for SRT subjects was approximately twice that seen in RLT. These findings, at this early stage in the development of behavioral treatments for insomnia in older adults, encourage further study. 相似文献
2.
3.
4.
We report an adult female with a rare giant choledochal cyst. The patient presented following a normal pregnancy with the classical triad of an abdominal mass associated with jaundice and right upper quadrant abdominal pain. The cyst was excised using an intramural technique and biliary reconstruction achieved with a Roux-en-Y hepaticojejunostomy. Our patient has remained well with no evidence of malignancy over a 12 year review period. The aetiology and current management of this condition are discussed. 相似文献
5.
6.
Na+ dependence of in vitro pancreatic amylase release 总被引:1,自引:0,他引:1
7.
Determination of optimal cryoprotectants and procedures for their addition and removal from human spermatozoa 总被引:9,自引:7,他引:9
The objective was to test the hypothesis that the optimal cryoprotective
agent for cryopreservation of human spermatozoa would be a solute for which
cells have the highest plasma membrane permeability, resulting in the least
amount of volume excursion during its addition and removal. To test this
hypothesis, theoretical simulations were performed using membrane
permeability coefficients to predict optimal procedures for the addition
and removal of a cryoprotectant. Simulations were performed using data from
four different cryoprotectants: (i) glycerol, (ii) dimethyl sulphoxide,
(iii) propylene glycol and (iv) ethylene glycol. Thermodynamic formulations
were applied to determine approaches for the addition and removal of 1 M
and 2 M final concentrations of cryoprotectant, allowing the spermatozoa to
maintain a cell volume within their osmotic tolerance limits. Based on
these data, ethylene glycol was predicted to be optimal for minimizing
volume excursions among the solutes evaluated. These predictions were then
experimentally tested using glycerol as the control cryoprotectant and
ethylene glycol as the experimental cryoprotectant. The results indicate
that there was a higher (P < 0.05) recovery of motile spermatozoa after
cryopreservation when using 1 M ethylene glycol than with 1 M glycerol,
supporting the hypothesis that use of the cryoprotectant for which the cell
has the highest permeability will result in higher cell survival.
相似文献
8.
Comparison of isolation of Haemophilus vaginalis (Corynebacterium vaginale) from peptone-starch-dextrose agar and Columbia colistin-nalidoxic acid agar.
下载免费PDF全文
![点击此处可从《Journal of clinical microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
A total of 447 cervical or vaginal specimens were inoculated in parallel onto peptone-starch-dextrose (PSD) and Columbia colistin (10 mg/ml)-nalidixic acid (15 mug/ml) (CNA) agar and were incubated for 48 h at 35 degrees C in an atmosphere with 2 to 10% CO2. One hundred (22.4%) of the cultures were positive for Haemophilus vaginalis. Forty-eight of the isolates were recovered from both PSD and Columbia CNA agar, five from PSD only, and 47 from Columbia CNA agar only (P less than 0.001). On Columbia CNA agar, 76 of the isolates were detected after 24 h of incubation, and the remainder were detected within 4 days of incubation. 相似文献
9.
10.
Extent, pattern, and correlates of remote memory impairment in Alzheimer's disease and Parkinson's disease 总被引:1,自引:0,他引:1
Fama R Sullivan EV Shear PK Stein M Yesavage JA Tinklenberg JR Pfefferbaum A 《Neuropsychology》2000,14(2):265-276
Content and contextual memory for remote public figures and events was assessed with a modified version of the Presidents Test in patients with Alzheimer's disease (AD) or Parkinson's disease (PD). Contributions of executive functioning, semantic memory, and explicit anterograde memory to remote memory abilities were also examined. The AD group had temporally extensive deficits in content and contextual remote memory not accountable for by dementia severity. The PD group did not differ from the control group in remote memory, despite anterograde memory impairment. These results support the position that different component processes characterize remote memory, various mnemonic and nonmnemonic cognitive processes contribute to remote memory performance, and anterograde and remote memory processes are dissociable and differentially disrupted by neurodegenerative disease. 相似文献