全文获取类型
收费全文 | 769篇 |
免费 | 29篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 13篇 |
儿科学 | 3篇 |
妇产科学 | 4篇 |
基础医学 | 96篇 |
口腔科学 | 17篇 |
临床医学 | 31篇 |
内科学 | 79篇 |
皮肤病学 | 1篇 |
神经病学 | 22篇 |
特种医学 | 26篇 |
外国民族医学 | 1篇 |
外科学 | 131篇 |
综合类 | 2篇 |
预防医学 | 21篇 |
眼科学 | 323篇 |
药学 | 19篇 |
肿瘤学 | 10篇 |
出版年
2022年 | 8篇 |
2021年 | 13篇 |
2020年 | 6篇 |
2019年 | 10篇 |
2018年 | 16篇 |
2017年 | 5篇 |
2016年 | 19篇 |
2015年 | 14篇 |
2014年 | 20篇 |
2013年 | 21篇 |
2012年 | 29篇 |
2011年 | 50篇 |
2010年 | 32篇 |
2009年 | 19篇 |
2008年 | 50篇 |
2007年 | 44篇 |
2006年 | 47篇 |
2005年 | 41篇 |
2004年 | 20篇 |
2003年 | 34篇 |
2002年 | 25篇 |
2001年 | 25篇 |
2000年 | 29篇 |
1999年 | 24篇 |
1998年 | 10篇 |
1997年 | 9篇 |
1996年 | 6篇 |
1995年 | 4篇 |
1994年 | 8篇 |
1993年 | 7篇 |
1992年 | 7篇 |
1991年 | 9篇 |
1990年 | 7篇 |
1989年 | 13篇 |
1988年 | 9篇 |
1987年 | 4篇 |
1986年 | 8篇 |
1985年 | 11篇 |
1984年 | 4篇 |
1981年 | 5篇 |
1979年 | 5篇 |
1978年 | 5篇 |
1977年 | 7篇 |
1975年 | 6篇 |
1971年 | 3篇 |
1970年 | 3篇 |
1968年 | 5篇 |
1966年 | 5篇 |
1965年 | 4篇 |
1954年 | 5篇 |
排序方式: 共有799条查询结果,搜索用时 14 毫秒
61.
O Holz I Zühlke E Jaksztat K C Müller L Welker M Nakashima K D Diemel D Branscheid H Magnussen R A J?rres 《The European respiratory journal》2004,24(4):575-579
Emphysema is characterised by a loss of alveolar structure, as reflected in elastic recoil and gas exchange. As fibroblasts play a key role in the maintenance of structure, the current authors hypothesised that their proliferation might be constitutively impaired in lung emphysema. Using explant cultures, lung fibroblasts were obtained from resected lungs of 10 patients with emphysema (median forced expiratory volume in one second (FEV1) 40% predicted) and 10 control patients (FEV1, 95% pred). The doubling time (DT) was measured over 4 days under standard conditions (10% foetal calf serum) prior and after cryopreservation. Additionally, in seven samples per group the total population doubling level (PDL) was determined. In emphysema, mean+/-sem DT was 33.6+/-2.8 h compared with 24.8+/-1.4 h in controls. The differences in DT were preserved after cryopreservation. Groups also differed in the initial slope of the PDL plot during long-term culture (up to 35 days). However, the median (range) maximum PDL did not differ significantly between groups (13.8 (7.4-22.6) versus 20.2 (11.2-25.5)). The current authors, therefore, suggest that the reduced proliferation rate in vitro of lung fibroblasts from patients with emphysema reflects a persistent, intrinsic failure of cellular replacement and maintenance in this disease, possibly in relation to pre-term aging. 相似文献
62.
Andrew C Kopel Petros E Carvounis Eric R Holz 《Ophthalmic surgery, lasers & imaging》2008,39(2):153-154
The first case of Bacillus cereus endophthalmitis following an intravitreous injection of bevacizumab is described. A 77-year-old man presented to a retina specialist with an active choroidal neovascularization related to age-related macular degeneration for which he received intravitreous bevacizumab (1.25 mg) and post-injection topical gatifloxacin. Eight hours later, the patient woke up with excruciating pain and a decline in vision associated with nausea and vomiting. A vitreous biopsy was performed that revealed B. cereus. Despite intravitreous injections of vancomycin and ceftazidime on day 1 and pars plana vitrectomy with repeat intravitreous injections on day 3, the eye did not recover light perception. 相似文献
63.
64.
Fast MR imaging methods should provide a familiar contrast behavior at a reduced scan time. The multi-spin echo approach (TSE) is one of the most promising techniques satisfying this condition. Although the data acquisition time is significantly reduced, image quality may still suffer from artifacts due to patient motion and flow. The radial turbo spin echo (rTSE) approach combines TSE methods and projection reconstruction (PR) techniques. In PR images, artifacts induced by patient motion or flow are known to have a different appearance with lower level of intensity. The contrast and artifact behavior of the rTSE approach has been investigated. The new technique has been applied to abdominal imaging with acquisition times shorter than 30 s and to heart imaging in combination with cardiac triggering. 相似文献
65.
Determination of low level exposure to volatile aromatic hydrocarbons and genotoxic effects in workers at a styrene plant. 总被引:2,自引:2,他引:0
下载免费PDF全文
![点击此处可从《Occupational and environmental medicine》网站下载免费的PDF全文](/ch/ext_images/free.gif)
O Holz G Scherer S Brodtmeier F Koops K Warncke T Krause A Austen J Angerer A R Tricker F Adlkofer et al. 《Occupational and environmental medicine》1995,52(6):420-428
OBJECTIVES--Low exposures to volatile aromatic hydrocarbons and cytogenetic effects in peripheral white blood cells were determined in 25 healthy workers employed in different areas of a styrene production plant in the former German Democratic Republic. The results were compared with 25 healthy unexposed controls (matched for age and sex) employed in the same company. METHODS--The concentrations of aromatic hydrocarbons determined from active air sampling in all areas of the factory (styrene: 73-3540 micrograms/m3 (< 0.01-0.83 ppm); ethylbenzene 365-2340 micrograms/m3 (0.08-0.53 ppm); benzene 73-3540 micrograms/m3 ( < 0.02-1.11 ppm); toluene 54-2960 micrograms/m3 (0.01-0.78 ppm); xylenes 12-94 micrograms/m3 ( < 0.01-0.02 ppm)) were considerably lower than in the pump house ( > 4000 micrograms/m3 styrene, ethylbenzene, benzene, and toluene; > 500 micrograms/m3 xylenes), which was only intermittently occupied for short periods. Passive personal monitoring, biomonitoring of exhaled air and metabolites (mandelic, phenylglyoxylic, trans, trans-muconic, hippuric, o-, m- and p-methylhippuric acids, and phenol) in urine samples collected before and after an eight hour working shift was used to assess individual exposure. Questionnaires and examination of company records showed that the historical exposure was far higher than that measured. Genotoxic monitoring was performed by nuclease P1-enhanced 32P-postlabelling of DNA adducts in peripheral blood monocytes, and DNA single strand breaks, sister chromatid exchange, and micronuclei in lymphocytes. The content of kinetochores in the micronuclei was determined by immunofluorescence with specific antibodies from the serum of CREST patients. RESULTS--No genotoxic effects related to exposure were detected by DNA adducts or DNA single strand breaks and sister chromatid exchange. The only effect related to exposure was an increase in kinetochore positive micronuclei in peripheral lymphocytes; the frequency of total micronuclei in peripheral lymphocytes did not change. Smoking was confirmed by measurement of plasma cotinine, and no confounding effect was found on any of the cytogenetic variables. CONCLUSIONS--Low occupational exposure to styrene, benzene, and ethylbenzene did not induce alterations of genotoxicological variables except kinetochore positive micronuclei. This is the first reported use of the CREST technique for an in vivo study in occupational toxicology, which thus could serve as a valuable and sensitive technique for toxicogenic monitoring. 相似文献
66.
Technique and results after primary valgisation osteotomy in 41 patients with femoral neck fractures are described. 2 non unions and 9 avascular femoral head necroses were observed. The primary valgisation most probably does not influence the rate of necrosis. When performed by accurate technique it lowers the incidence of non union of the femoral neck. Postoperative leg lengthening is always evident. The most current avoidable mistake is an external rotational deformity. The procedure requires proper preoperative planning. 相似文献
67.
Trauma und Berufskrankheit - Zusammenfassung In Streckstellung des Ellbogens kommt dem Processus coronoideus ulnae und dem Radiusköpfchen eine große Bedeutung für die... 相似文献
68.
Strom TQ Leskela J James LM Thuras PD Voller E Weigel R Yutsis M Khaylis A Lindberg J Holz KB 《Military medicine》2012,177(4):390-396
The present study conducted an exploratory examination of the relationship between self-reported symptoms of post-traumatic stress disorder and an expanded definition of risk-taking behaviors among 395 veterans at a large Midwestern Veterans Affairs Medical Center. Post-traumatic stress disorder symptoms were associated with elevated rates of substance use, thrill seeking, aggression, risky sexual practices, and firearm possession. Results indicated that suicidal ideation and aggressive driving behavior were among the most frequently reported. The present findings hold significant public health implications and highlight the need to attend to risk-taking behaviors in treatment planning. 相似文献
69.
70.