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   8154篇
  免费   687篇
  国内免费   22篇
耳鼻咽喉   120篇
儿科学   228篇
妇产科学   257篇
基础医学   1119篇
口腔科学   213篇
临床医学   703篇
内科学   1725篇
皮肤病学   136篇
神经病学   752篇
特种医学   356篇
外科学   1362篇
综合类   59篇
一般理论   6篇
预防医学   669篇
眼科学   151篇
药学   385篇
中国医学   8篇
肿瘤学   614篇
  2023年   87篇
  2022年   174篇
  2021年   320篇
  2020年   193篇
  2019年   261篇
  2018年   295篇
  2017年   222篇
  2016年   232篇
  2015年   313篇
  2014年   333篇
  2013年   382篇
  2012年   575篇
  2011年   490篇
  2010年   304篇
  2009年   235篇
  2008年   369篇
  2007年   414篇
  2006年   344篇
  2005年   327篇
  2004年   312篇
  2003年   262篇
  2002年   252篇
  2001年   183篇
  2000年   192篇
  1999年   177篇
  1998年   63篇
  1997年   65篇
  1996年   45篇
  1995年   35篇
  1994年   49篇
  1993年   40篇
  1992年   107篇
  1991年   117篇
  1990年   98篇
  1989年   89篇
  1988年   68篇
  1987年   80篇
  1986年   76篇
  1985年   60篇
  1984年   38篇
  1983年   37篇
  1979年   37篇
  1978年   34篇
  1975年   26篇
  1974年   26篇
  1973年   39篇
  1972年   31篇
  1971年   33篇
  1969年   37篇
  1966年   34篇
排序方式: 共有8863条查询结果,搜索用时 15 毫秒
11.
The study objectives were to analyze the changes in exhaled carbon monoxide (COex) induced by histamine provocation challenge in asthmatic patients and to evaluate the relationship between COex and airway sensitivity and reactivity. Levels of COex were measured in 105 nonsmoking mildly asthmatic subjects before and after histamine provocation challenge. Dose-response curves were characterized by their sensitivity (PD20) and reactivity. Dose-response slope (DRS), continuous index of responsiveness (CIR), and bronchial reactivity index (BRI) were determined as reactivity indices. Bronchial challenge was positive for 47 subjects and negative for 58. The COex levels rose significantly after bronchial challenge in the positive response group (4.49 ± 0.4 vs. 5.74 ± 0.57 ppm, p = 0.025) and in the negative response group (2.84 ± 0.25 vs 4.00 ± 0.41 ppm, p = 0.000). An inverse relation between basal COex and PD20 was found (r = - 0.318, p = 0.030). In all subjects, a proportional direct relationship between COex and DRS (r = 0.214, p = 0.015), CIR (r = 0.401, p = 0.000), and BRI (r = 0.208, p = 0.012) was observed. On stepwise multiple linear regression analysis, COex only significantly correlated with CIR (multiple r2 = 0.174, p = 0.000). In conclusion, exhaled CO determination is a noninvasive inflammatory marker of the respiratory tract, which shows an acceptable association with airway hyperresponsiveness.  相似文献   
12.
We report a case of multiple endocrine neoplasia type I and hypernephroma. Parathyroid hyperplasia, adrenocortical hyperplasia, a nodular goiter, multiple lipomas, a chromophobe adenoma of the pituitary and hypernephroma had all been diagnosed previously. All but the last are features consistent with the diagnosis of multiple endocrine neoplasia type I (Wermer's syndrome). The association of multiple endocrine neoplasia type I and hypernephroma may represent a new manifestation of this pleiotropic syndrome.  相似文献   
13.
We have shown previously that progesterone linked with bovine serum albumin at position 3 of the progesterone molecule (P-3-BSA) was effective in modulating (both stimulating and inhibiting) amphetamine (AMPH)-evoked dopamine (DA) release in vitro from superfused corpus striatal (CS) tissue fragments of ovariectomized estrogen-primed rats. To examine the stereospecificity of this effect, progesterone linked with bovine serum albumin at position 11 (P-11-BSA) and deoxycorticosterone linked with bovine serum albumin at position 21 (DOC-BSA) were tested for their ability to modulate amphetamine-stimulated DA release in vitro when administered in either a pulsatile or a continuous infusion mode at different doses. The results demonstrate that a specific orientation of the P-BSA molecule is required for differential modulation of AMPH stimulated DA release from the CS of ovariectomized estrogen-treated rats, since DOC-BSA was ineffective and P-11-BSA showed only a stimulatory effect.  相似文献   
14.
Between 4/1986 to 1/1989, 74 orthotopic liver transplantation were performed in 62 patients (62 first liver transplants, 10 as second graft and two as a third graft); 57 in adults and 17 in children. The main indication for the operation was liver cirrhosis (61.4%) (the most frequent etiology was alcoholic cirrhosis, 28.5%). Six cirrhotic patients had a hepatocarcinoma (9.6%). Two received a liver and kidney transplant due to terminal renal insufficiency and hemodialysis. The most frequent indication in children was biliary atresia (33.3%). Six patients had a fulminal liver failure (9.6%). AB0 blood group compatibility was identical in 87.5%, compatible in six and incompatible in three patients. Total orthotopic liver transplantation was performed in 67 patients, and size-reduced liver was indicated in 7 patients. Extracorporeal veno-venous bypass was used in adults but never in children. In 93.1% of the transplants a single hepatic artery was anastomosed to the recipient and in 6.9% a double anastomosis was performed. In 62.5% of the patients a end-to-end choledocho-choledochostomy was performed and in 34.8% hepatico-jejunostomy was indicated. Three months postoperative mortality rate was 12.9%. Arterial stenosis and thrombosis were the most frequent complication.  相似文献   
15.
16.
Rats fed wet diets containing saccharin consumed 12-14% more energy and gained 24-55% more weight than rats fed the same diets without saccharin. Saccharin-induced stimulation of intake was usually not so pronounced during the first week as during subsequent weeks of each experiment. Similar results were obtained using diets high in starch and fat. However, these effects could be obliterated by simply exposing the rats to unsweetened (plain) diet or to saccharin in water for several days before the sweetened diets were introduced. Furthermore, although stimulation of intake by saccharin was observed with diets containing 80% water, no such effect was observed with a diet containing 60% water. Rats given low-energy sweetened water in addition to their 80% water diet consumed substantially more fluid but not more or less energy than rats given unsweetened water. Preference tests suggest that saccharin increases diet palatability only very slightly; this finding is one of several observations suggesting that stimulation of intake by saccharin cannot be interpreted in terms of increased diet palatability. These results suggest that dietary hyperphagia results from the interaction between innate and learned responses to the taste of foods. Osmotic factors did not seem to exert a major influence in these experiments.  相似文献   
17.
The purpose of this study was to evaluate the use of serum fibronectin and serum somatomedin-C as nutritional markers during enteral nutrition support (ENS) of critically ill, traumatized patients using an enteral product containing high concentrations of branched-chain amino acids. Twelve critically injured patients received a standard enteral formula with 30 g of a 44% branched-chain amino acid supplement added to each liter of formula. Fibronectin concentration, somatomedin-C concentration, and nitrogen balance were measured on study days 1, 4, 7, 14, 21, 28 or until adequate oral intake began. Both fibronectin and somatomedin-C concentrations increased significantly from baseline by day 7 of ENS. Nitrogen balance increased significantly from baseline by day 4. On days 14 and 21, only somatomedin-C and nitrogen balance increased significantly from baseline. Nitrogen balance was significantly correlated with somatomedin-C concentration (r = 0.53, p less than 0.01), cumulative caloric intake (r = 0.68, p less than 0.01), and cumulative nitrogen intake (r = 0.72, p less than 0.01). The results of this study suggest that serum somatomedin-C is useful and serum fibronectin has potential in monitoring nutrition support response in critically ill, traumatized patients.  相似文献   
18.
SEVERAL SCIENTIFIC AND GENERAL MEDICAL JOURNALS publish full-length articles on their Web sites and abridged versions in their print journals. We surveyed a stratified random sample of BMJ readers and authors to elicit their preferred format for the abridged print version. Each participant received a research paper abridged in 3 different formats: conventional abridged version, journalistic version and enhanced-abstract version. Overall, 45% (95% confidence interval [CI] 42%–48%) of the respondents said they liked the conventional version most, 31% (95% CI 28%–34%) preferred the journalistic version and 25% (95% CI 22%–27%) preferred the enhanced-abstract version. Twenty-eight percent (95% CI 25%–32%) indicated that use of the journalistic format for abridged articles would very likely stop them from submitting papers to BMJ, and 13% (95% CI 11%–16%) said the use of the enhanced-abstract version would stop them from submitting to BMJ. Publishers of general medical journals who publish shortened articles should consider that authors and readers prefer a more conventional style of abridged papers.  相似文献   
19.
In a consecutive double-blind cross-over study, 18 females with detrusor instability were treated with an anticholinergic and calcium antagonistic agent terodiline 25 mg bid or placebo for 3 weeks; cross-over took place after a wash-out period of 1 week. The efficacy of the drug was investigated at the end of each treatment period by means of drug preference, micturition charts, pad usage, bladder and urethral mucosal perception threshold and bulbocavernosus reflex latency measurement. Serum levels of terodiline were estimated at the end of each treatment period and all side effects were reported. The preference for the drug was statistically significant (P less than 0.01): 14 patients preferred the drug, one preferred the placebo and three had no preference. A small but statistically significant reduction was found in 24-h micturition frequency (P less than 0.05). Cystometry showed an increase in volume at first sensation, an increase in volume at detrusor contraction and a tendency towards an increase in bladder capacity, whereas detrusor contraction pressure was unchanged. Median serum levels of the drug were 559 ng/ml (range 203-1117). No serious side effects were reported. It was concluded that terodiline should be considered as an alternative drug in the treatment of motor urge incontinence.  相似文献   
20.
BACKGROUND Dermatologic procedures often cause some degree of pain. A self-warming patch containing lidocaine and tetracaine (L/T) was developed to provide topical local anesthesia prior to painful procedures.
OBJECTIVES To evaluate the safety and efficacy of a self-warming L/T patch to provide anesthesia in adult patients undergoing minor dermatologic procedures.
METHODS An active or placebo study drug was placed on adults 30 minutes prior to minor dermatologic surgical procedures in a prospectively randomized, double-blinded manner. Subcutaneous lidocaine injection was available during the procedure as a rescue medication if requested by the subject. Immediately following the procedure, the subjects, the investigator, and an independent observer rated pain intensity and adverse events were recorded.
RESULTS Patient-reported pain intensity was significantly lower in the L/T patch group (   p < .001  ). Investigators and an independent observer rated the pain in the L/T patch group to be less than in the placebo patch group (   p = .004  and   p < .001  , respectively). Forty-nine percent of patients in the placebo group required rescue subcutaneous lidocaine compared with 22% in the L/T patch study group (   p = .008  ). One patient in the L/T patch group reported a transient moderate burning sensation.
CONCLUSION The self-warming L/T patch was effective in providing clinically useful local anesthesia for minor dermatologic procedures in adult patients.
ZARS, INC., PROVIDED SUPPORT VIA A SPONSORED RESEARCH GRANT TO THE UNIVERSITY OF MIAMI.  相似文献   
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