首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   552篇
  免费   23篇
  国内免费   9篇
耳鼻咽喉   2篇
儿科学   9篇
妇产科学   1篇
基础医学   37篇
口腔科学   8篇
临床医学   51篇
内科学   110篇
皮肤病学   5篇
神经病学   35篇
特种医学   70篇
外科学   35篇
综合类   56篇
预防医学   32篇
眼科学   4篇
药学   94篇
中国医学   1篇
肿瘤学   34篇
  2022年   2篇
  2021年   6篇
  2020年   3篇
  2019年   7篇
  2018年   5篇
  2017年   7篇
  2016年   8篇
  2015年   12篇
  2014年   8篇
  2013年   15篇
  2012年   20篇
  2011年   21篇
  2010年   16篇
  2009年   33篇
  2008年   30篇
  2007年   28篇
  2006年   19篇
  2005年   22篇
  2004年   23篇
  2003年   12篇
  2002年   15篇
  2001年   14篇
  2000年   16篇
  1999年   12篇
  1998年   17篇
  1997年   20篇
  1996年   13篇
  1995年   9篇
  1994年   4篇
  1993年   5篇
  1992年   10篇
  1991年   8篇
  1990年   12篇
  1989年   12篇
  1988年   17篇
  1987年   13篇
  1986年   17篇
  1985年   10篇
  1984年   10篇
  1983年   12篇
  1982年   10篇
  1981年   4篇
  1980年   2篇
  1977年   2篇
  1976年   1篇
  1975年   2篇
  1958年   11篇
  1957年   4篇
  1952年   2篇
  1951年   1篇
排序方式: 共有584条查询结果,搜索用时 15 毫秒
1.
de Vries Reilingh  TS  van Geldere  D  Langenhorst  BLAM  de Jong  D  van der Wilt  GJ  van Goor  H  Bleichrodt  RP 《Hernia》2004,8(1):56-59
Polypropylene mesh is widely used for the reconstruction of incisional hernias that cannot be closed primarily. Several techniques have been advocated to implant the mesh. The objective of this study was to evaluate, retrospectively, early and late results of three different techniques, onlay, inlay, and underlay. The records of 53 consecutive patients with a large midline incisional hernia — 25 women and 28 men, mean age 60.4 (range 28–94) — were reviewed. Polypropylene mesh was implanted using the onlay technique in 13 patients, inlay in 23 patients, and underlay in 17 patients. Either the greater omentum or a polyglactin mesh was interponated between the mesh and the viscera. The records of these 53 patients were reviewed with respect to: size and cause of the hernia, pre- and postoperative mortality and morbidity, with special attention to wound complications. Patients were invited to attend the outpatient clinic at least 12 months after implantation of the mesh for physical examination of the abdominal wall. Postoperative complications occurred in 14 (26.4%) patients. The onlay technique had significantly more complications, as compared to both other techniques. Reherniation occurred in 15 (28.3%) patients. The reherniation rate of the inlay technique was significantly higher than after the underlay technique (44% vs 12%, P=0.03) and tended to be higher than the onlay technique (44% vs 23%, P=0.22). Repair of large midline incisional hernias with the use of a polypropylene mesh carries a high risk of complications and has a high reherniation rate. The underlay technique seems to be the better technique.  相似文献   
2.
The purpose of this study was to determine the normal characteristics of the lower extremity arterial system as seen with color Doppler. A total of 420 arterial segments from the level of the proximal abdominal aorta to the distal tibial and peroneal vessels were examined with a color ultrasound scanner in 10 normal volunteers. Each arterial segment was examined for the presence of triphasic flow, wall irregularities, calcification, bruits, collaterals, and post-stenotic flow patterns. Standard duplex spectral waveform data were also obtained at each site. As expected, triphasic flow was present and detected by color Doppler in the majority of arterial segments. Color patterns suggesting the presence of bruits, collaterals, or post-stenotic flow were absent in all cases.  相似文献   
3.
The authors report the clinical and laboratory findings of a patient who had severe immune hemolytic anemia due to hydrochlorothiazide (HCTZ). In this case, the HCTZ antibody reacted not only with other thiazide and thiazide-like drugs, but also with a chemically unrelated diuretic, ethacrynic acid. These results indicate that HCTZ antibody activity is not restricted solely to the thiazides and imply that therapy with any of the reactive drugs would be contraindicated for this patient. The serologic screening for drug reactivity may be useful for selecting alternative therapy for patients with drug-induced immune hemolytic anemia.  相似文献   
4.
Several past studies have reported reliable changes in reaction time performance and self-rated withdrawal scores as a consequence of cigarette deprivation. The purpose of the present study was to determine, prospectively, the effect 24 h of smokeless tobacco deprivation in regular users has on performance and the associated withdrawal symptomology. Forty smokeless tobacco users (Copenhagen brand) were randomly divided evenly into two groups gen brand) were randomly divided evenly into two groups (N=20)24 h of deprivation and no deprivation. A third group of ten nonchewers was added as another control group. The results indicated that behavioral, subjective and physiological changes are associated with smokeless tobacco deprivation in regular users. These include increased craving scores, reaction time, self-rated withdrawal symptoms and decreased heart rate.  相似文献   
5.
Extracellular matrix is the principal component of the fibrous caps of atherosclerotic plaques and intimal hyperplastic lesions of reconstructed arteries. Interstitial collagen form an important part of the matrix, and the balance between collagen synthesis and degradation by interstitial collagenase (matrix metalloproteinase-1, MMP-1) may determine whether plaques rupture or vessels develop stenosis. We examined type I procollagen gene expression in human atherosclerotic and restenotic carotid arteries using in situ messenger RNA (mRNA) hybridization and the expression of MMP-1 and its endogenous inhibitor (tissue inhibitor of metalloproteinases-1, TIMP-1) by immunohistochemistry. Compared with normal arteries, atherosclerotic plaques bed increased expression of immunoreactive MMP-1 and TIMP-1 with modest increase of type 1 procollagen mRNA. Early restenotic lesions (< 1.5 years) contained abundant type I procollagen mRNA but little immunoreactive MMP-1 and TIMP-1. Late restenotic lesions (> 4 years) resembled atheroma and exhibited increased immunoreactive MMP-1 and TIMP-1 as well as abundant type I procollagen mRNA. Compared with atherosclerotic plaques, type I procollagen is increased and MMP-1 is decreased in early restenotic lesions. MMP-1 and TIMP-1 expressions are upregulated in lesions with a clear atheroma. These findings suggest that the balance between proteolysis and matrix synthesis may influence both the stability of atheromatous plaques and the development of restenotic lesions.  相似文献   
6.
Pediatric health screening procedures, both prenatal and postnatal, have a tremendous potential in improving the health status of children and in turn reducing the resource burden on the parents and the State. The existing recommendations, inherent problems and different screening procedures are discussed. The need for suitable mass screening pediatric procedures in the Indian context is stressed.KEY WORDS: Pediatric screening procedures  相似文献   
7.
BACKGROUND: This study was undertaken to evaluate the long-term smoking cessation efficacy of varying doses of transdermal nicotine delivery systems 4 to 5 years post-quit day. METHODS: A follow-up study was conducted 48 to 62 months after quit day among patients who were enrolled in the Transdermal Nicotine Study Group investigation. The latter study included group smoking cessation counseling and randomized assignment to 21, 14, or 7 mg nicotine patches or placebo patches. Seven of nine smoking cessation research centers participated in the long term follow-up investigation. RESULTS: The self-reported continuous quit rate among patients originally assigned 21 mg (20.2%) was significantly higher than rates for patients assigned 14 mg (10.4%), 7 mg (11.8%), or placebo patches (7.4%). Log rank survival analysis found no difference in relapse rates after 1 year postcessation. Smokers under age 30 years were significantly less likely to be abstinent at long term follow-up compared to smokers > or = 30 years of age (3 vs 13%, respectively). Mean weight gain in confirmed continuous quitters was 10.1 kg in men and 8.0 kg in women. Of the 63 continuous abstainers surveyed, 30 respondents (48%) reported that they no longer craved cigarettes, and no individual reported daily craving for cigarettes. CONCLUSIONS: Nicotine patch therapy with 21 mg/day patches resulted in a significantly higher long-term continuous abstinence rate compared to lower dose patches and placebo. Relapse rates among the various treatment conditions were similar after 1 year postcessation.  相似文献   
8.
Of the 253 neonates admitted to a neonate intensive care unit during the period Jan 91 to Sep 93, 43 neonates died. Autopsy was done in 23 of these (53%). The mean duration of stay of the neonates in the intensive care unit prior to death was 5.6 days (range 2 hours to 10 days). Antemortem diagnoses included asphyxia neonatorum (4), meconium aspiration syndrome (2), septicemia (5), prematurity (3), birth trauma (2), congenital anomalies (2), hypoxic ischemic encephalopathy (1), and non-specific diagnosis (4). There were 6 major autopsy findings that, if known prior to death, would have altered clinical management and might have resulted in cure or prolonged survival. There were 8 additional major findings that, if known prior to death, would not have altered management There were 14 minor findings related to major diagnoses but unrelated to the primary cause of death.KEY WORDS: Autopsy, Cause of death, Perinatal mortality  相似文献   
9.
To determine the prevalence of thyroid hormone abnormalities and generalized resistance to thyroid hormone in a population of children with attention deficit hyperactivity disorder (ADHD) as compared to reference ranges determined from a control population and hence to determine if routine thyroid hormone screening in children with non-familial ADHD is indicated.

Method:


Children attending the State Child Development Centre in Perth, Western Australia with ADHD, as defined by the Diagnostic and Statistical Manual of Mental Disorders (fourth edition) provided the study population. The control population consisted of 353 normal children with a history of allergy in whom radioallergosorbent (RAST) testing was being performed.

Results:


The prevalence of thyroid hormone abnormalities in the study population was 2.3% (95% CI 0.6%, 5.7%). There were no cases of generalized resistance to thyroid hormone. The prevalence of thyroid hormone abnormalities in the general population of children and adolescents has been reported to vary between 1 and 3.7%.

Conclusion:


Routine thyroid hormone screening is not indicated in children with non-familial ADHD.  相似文献   
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号