全文获取类型
收费全文 | 906篇 |
免费 | 56篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 59篇 |
妇产科学 | 4篇 |
基础医学 | 124篇 |
口腔科学 | 31篇 |
临床医学 | 157篇 |
内科学 | 178篇 |
皮肤病学 | 21篇 |
神经病学 | 56篇 |
特种医学 | 113篇 |
外科学 | 72篇 |
综合类 | 9篇 |
预防医学 | 46篇 |
眼科学 | 2篇 |
药学 | 67篇 |
肿瘤学 | 44篇 |
出版年
2023年 | 3篇 |
2019年 | 8篇 |
2018年 | 9篇 |
2017年 | 5篇 |
2016年 | 8篇 |
2015年 | 8篇 |
2014年 | 15篇 |
2013年 | 37篇 |
2012年 | 27篇 |
2011年 | 39篇 |
2010年 | 37篇 |
2009年 | 28篇 |
2008年 | 21篇 |
2007年 | 40篇 |
2006年 | 32篇 |
2005年 | 29篇 |
2004年 | 20篇 |
2003年 | 19篇 |
2002年 | 20篇 |
2001年 | 22篇 |
2000年 | 22篇 |
1999年 | 25篇 |
1998年 | 47篇 |
1997年 | 46篇 |
1996年 | 42篇 |
1995年 | 25篇 |
1994年 | 30篇 |
1993年 | 24篇 |
1992年 | 19篇 |
1991年 | 18篇 |
1990年 | 23篇 |
1989年 | 18篇 |
1988年 | 42篇 |
1987年 | 26篇 |
1986年 | 14篇 |
1985年 | 13篇 |
1984年 | 17篇 |
1983年 | 15篇 |
1982年 | 15篇 |
1981年 | 11篇 |
1980年 | 7篇 |
1979年 | 8篇 |
1978年 | 4篇 |
1977年 | 8篇 |
1976年 | 5篇 |
1975年 | 3篇 |
1974年 | 4篇 |
1942年 | 3篇 |
1941年 | 2篇 |
1939年 | 2篇 |
排序方式: 共有984条查询结果,搜索用时 15 毫秒
1.
Saifudin Rashiq Diane Edlund Bruce D Dick 《BMC medical informatics and decision making》2006,6(1):8-6
Background
There are no published utilities for the post-anesthesia state obtained by the standard gamble method (SG). 相似文献2.
Rupture of the distal biceps tendon: evaluation with MR imaging 总被引:2,自引:0,他引:2
3.
Radiation therapy has been a major treatment option for patients with prostate cancer with documented efficacy over the last 30 years. Recent research has shown a correlation between improved local control, disease-free survival, and overall survival and dose delivered. Excessive dose to the rectum is one of the leading causes of morbidity in the treatment of prostate cancer. The RTOG and others have suggested dose limitations based on various treatment parameters. Intensity-modulated radiation therapy (IMRT) is becoming more widely used, with the goal of improving dose coverage while limiting morbidity. In an effort to evaluate our inverse-planning technique relative to our forward-planned technique based on rectal dose, 2 plans were generated on 10 patients. One plan was generated with 9-field forward planning, using 2 posterior obliques to decrease dose to the rectum. The other plan utilized inverse IMRTplanning. To evaluate dose to the rectum, we compared the dose gradient from the posterior edge of the prostate across the anterior third of the rectal wall. This gradient, which is not part of the IMRT planning objectives, proved useful in assessing plan differences, and led to new dose objectives for certain IMRT plans. 相似文献
4.
Androgen receptor YAC transgenic mice carrying CAG 45 alleles show trinucleotide repeat instability 总被引:1,自引:15,他引:1
La Spada AR; Peterson KR; Meadows SA; McClain ME; Jeng G; Chmelar RS; Haugen HA; Chen K; Singer MJ; Moore D; Trask BJ; Fischbeck KH; Clegg CH; McKnight GS 《Human molecular genetics》1998,7(6):959-967
X-linked spinal and bulbar muscular atrophy (SBMA) is caused by a CAG
repeat expansion in the first exon of the androgen receptor (AR) gene.
Disease-associated alleles (37-66 CAGs) change in length when transmitted
from parents to offspring, with a significantly greater tendency to shift
size when inherited paternally. As transgenic mice carrying human AR cDNAs
with 45 and 66 CAG repeats do not display repeat instability, we attempted
to model trinucleotide repeat instability by generating transgenic mice
with yeast artificial chromosomes (YACs) carrying AR CAG repeat expansions
in their genomic context. Studies of independent lines of AR YAC transgenic
mice with CAG 45 alleles reveal intergenerational instability at an overall
rate of approximately 10%. We also find that the 45 CAG repeat tracts are
significantly more unstable with maternal transmission and as the
transmitting mother ages. Of all the CAG/CTG repeat transgenic mice
produced to date the AR YAC CAG 45 mice are unstable with the smallest
trinucleotide repeat mutations, suggesting that the length threshold for
repeat instability in the mouse may be lowered by including the appropriate
flanking human DNA sequences. By sequence-tagged site content analysis and
long range mapping we determined that one unstable transgenic line has
integrated an approximately 70 kb segment of the AR locus due to
fragmentation of the AR YAC. Identification of the cis - acting elements
that permit CAG tract instability and the trans -acting factors that
modulate repeat instability in the AR YAC CAG 45 mice may provide insights
into the molecular basis of trinucleotide repeat instability in humans.
相似文献
5.
6.
It is well recognized that the ability to cryopreserve unfertilizedhuman oocytes would make a significant contribution to infertilitytreatment. However, despite considerable interest, very fewsuccessful pregnancies have arisen from cryopreserved oocytesafter thawing, insemination and transfer of the subsequent embryo.The reasons for this lack of progress may well result from adearth of information on how the various biophysical changesduring a cryopreservation regimen affect human oocyte function.Recently, fundamental studies on the effects of cooling, membranepermeability, cryoprotectant addition and ice formation havebeen performed on human oocytes by a number of groups, and theseform the basis of the current review. It is likely that successfulhuman oocyte cryopreservation will only follow once these factorsare fully understood, but the existing base of knowledge shouldprovide a platform for further improvements in the techniquescurrently employed. 相似文献
7.
8.
KM Kanal NJ Hangiandreou AM Sykes HE Eklund PA Araoz JA Leon BJ Erickson 《Journal of digital imaging》2002,14(1):30-37
The aims of this work were to measure the accuracy of one continuous speech recognition product and dependence on the speaker's
gender and status as a native or nonnative English speaker, and evaluate the product's potential for routine use in transcribing
radiology reports. IBM MedSpeak/Radiology software, version 1.1 was evaluated by 6 speakers. Two were nonnative English speakers,
and 3 were men. Each speaker dictated a set of 12 reports. The reports included neurologic and body imaging examinations performed
with 6 different modalities. The dictated and original report texts were compared, and error rates for overall, significant,
and subtle significant errors were computed. Error rate dependence on modality, native English speaker status, and gender
were evaluated by performing ttests. The overall error rate was 10.3 +/- 3.3%. No difference in accuracy between men and women
was found; however, significant differences were seen for overall and significant errors when comparing native and nonnative
English speakers (P = .009 and P = .008, respectively). The speech recognition software is approximately 90% accurate, and
while practical implementation issues (rather than accuracy) currently limit routine use of this product throughout a radiology
practice, application in niche areas such as the emergency room currently is being pursued. This methodology provides a convenient
way to compare the initial accuracy of different speech recognition products, and changes in accuracy over time, in a detailed
and sensitive manner. 相似文献
9.
Frequent transmission of enterococcal strains between mechanically ventilated patients treated at an intensive care unit 下载免费PDF全文
The objectives of this investigation were to study the respiratory tract colonization and transmission of enterococci between 20 patients treated with mechanical ventilation at an intensive care unit (ICU), to compare genotyping with phenotyping, and to determine the antibiotic susceptibilities of the isolated enterococci. Samples were collected from the oropharynx, stomach, subglottic space, and trachea within 24 h of intubation, every third day until day 18, and thereafter every fifth day until day 33. Enterococcal isolates (n = 170) were analyzed by pulsed-field gel electrophoresis and with the PhenePlate (PhP) system. The antimicrobial susceptibilities to five agents were determined. Seventeen of the 20 subjects were colonized with enterococci in the respiratory tract; 12 were colonized in the lower respiratory tract. Genotype analyses suggested that 13 patients were involved in a transmission event, including all patients intubated more than 12 days. In conclusion, colonization of resistant enterococci in the respiratory tract of intubated patients treated at an ICU was common. Transmission of enterococci between patients occurred frequently. Prolonged intubation period seems to be a risk factor for enterococcal cross-transmission. 相似文献
10.
C. Edlund S. Sabouri C. E. Nord 《European journal of clinical microbiology & infectious diseases》1998,17(3):193-195
The in vitro activity of BAY 12-8039 against 360 anaerobic clinical isolates was determined by the agar dilution method and compared to that of five other antimicrobial agents. BAY 12-8039 and imipenem were the most active agents tested. The following MIC90 values were determined for BAY 12-8039Peptostreptococcus spp. (50 isolates), 1 mg/l;Propionibacterium acnes (30 isolates), 0.25 mg/l;Clostridium perfringens (30 isolates), 0.5 mg/l;Clostridium difficile (50 isolates), 2 mg/l;Bacteroides fragilis (50 isolates), 1 mg/l;non- fragilis Bacteroides, Porphyromonas, andPrevotella spp. (100 isolates), 2 mg/l; andFusobacterium spp. (50 isolates), 0.25 mg/l. The results of the present study show that BAY 12-8039 may be useful in the treatment and prophylaxis of anaerobic infections. 相似文献