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   445篇
  免费   41篇
  国内免费   2篇
耳鼻咽喉   96篇
儿科学   10篇
妇产科学   3篇
基础医学   48篇
临床医学   46篇
内科学   47篇
皮肤病学   12篇
神经病学   33篇
特种医学   45篇
外科学   52篇
综合类   11篇
预防医学   18篇
眼科学   16篇
药学   33篇
中国医学   1篇
肿瘤学   17篇
  2023年   2篇
  2021年   2篇
  2020年   2篇
  2019年   5篇
  2018年   5篇
  2017年   10篇
  2016年   3篇
  2015年   12篇
  2014年   11篇
  2013年   18篇
  2012年   23篇
  2011年   15篇
  2010年   13篇
  2009年   13篇
  2008年   20篇
  2007年   23篇
  2006年   37篇
  2005年   19篇
  2004年   28篇
  2003年   27篇
  2002年   25篇
  2001年   15篇
  2000年   17篇
  1999年   14篇
  1998年   17篇
  1997年   9篇
  1996年   3篇
  1995年   7篇
  1994年   3篇
  1993年   7篇
  1992年   11篇
  1991年   9篇
  1990年   3篇
  1989年   4篇
  1988年   6篇
  1987年   5篇
  1986年   2篇
  1985年   5篇
  1984年   5篇
  1983年   2篇
  1979年   4篇
  1977年   3篇
  1975年   2篇
  1974年   2篇
  1973年   3篇
  1972年   3篇
  1969年   2篇
  1968年   3篇
  1967年   2篇
  1965年   2篇
排序方式: 共有488条查询结果,搜索用时 15 毫秒
1.
2.
Anecdotal reports suggest that dysgeusia may be related to a variety of systemic factors, including bladder outflow obstruction. This is a hospital-based case-controlled study involving 111 patients who were admitted to urological wards for transurethral resection of the prostate for benign prostatic disease with age- and sex-matched control of 137 subjects. We used a semi-structured questionnaire by a trained interviewer at admission (preoperative), at the postoperative period and at follow-up between 4–6 months (median 5 months). Analysis used unpaired t-test and X2 test. The incidence of dysgeusia was 22% in the study group and 13% in the control group (P=N.S.). However, strikingly, the dysgeusia in the study group was relieved promptly by relief of urinary obstruction in 100% of cases and did not return within the follow-up period. The mechanism of the dysgeusia associated with dysuria in benign prostatic disease is unknown, but we suggest that the dysgeusia could be from the stress of dysuria or due to a release of an unknown chemical from the urinary tract or an overflow of neural impulse from pontine/cortical micturition centres to the taste centres. An association between dysgeusia and dysuria has not been described before.  相似文献   
3.
Laryngeal Transplantation in 2005: A Review   总被引:3,自引:0,他引:3  
There is no good surgical, medical or prosthetic solution to the problems faced by those with a larynx whose function is irreversibly damaged by tumor or trauma. Over the past 10 years, the pace of research designed to establish laryngeal transplantation as a therapeutic option for these persons has increased steadily. The biggest milestone in this field was the world's first true laryngeal transplant performed in Cleveland, Ohio in 1998. The recipient's graft continues to function well, in many respects, even after 7 years. However, it has also highlighted the remaining barriers to full-scale clinical trials. Stimulated by these observations, several groups have accumulated data which point to answers to some of the outstanding questions surrounding functional reinnervation and immunomodulation. This review seeks to outline the progress achieved in this field by 2005 and to point the way forward for laryngeal transplantation research in the 21st century.  相似文献   
4.
The chemistry of aluminum and silicon in relation to Alzheimer's disease   总被引:3,自引:0,他引:3  
Aluminosilicates have been identified at the core of senile plaques in Alzheimer's disease, and aluminum has been found within neurons bearing neurofibrillary tangles. Here we show that aluminum species interact with silicic acid, Si(OH)4--a normal component of plasma--to form aluminosilicate species solubilized by citrate. A switch in the binding of aluminum from silicate to phosphate at pH less than 6.6 calls attention to the strong binding of cationic aluminum species to proximate phosphate groups, as in the inositol phosphates, and to the potential effect on the activity of the phosphoinositide-derived intracellular messenger system. The chemistry may throw light on the debated relationship between aluminum and Alzheimer's disease.  相似文献   
5.
6.
Middle ear effusion was obtained from children with otitis media with effusion and separated into thick (mucoid) and thin (serous) pools. Both effusion types contained similar amounts of non-dialysable solids. However, the thick effusions contained more mucus glycoprotein than the thin effusions, 25% and 8.2% respectively. Amino acid and carbohydrate analysis of the CsCl purified mucus glycoproteins demonstrated that the glycoprotein from the thick and thin effusions differed in their protein core, those from the thick effusions possessing a higher percentage of serine and threonine, the amino acids to which the sugar side-chains attach. They are also more glycosylated. N-acetyl cysteine and mercaptoethanol caused a fall in the viscosity of solutions of purified middle ear glycoprotein and effusion homogenate. However, longer term incubation caused a rise above the starting viscosity. This effect was concentration-dependent, and was mediated by low molecular weight components in the effusion and not the mucus glycoprotein. S-carboxymethyl cysteine had no effect on the viscosity of either the purified mucus glycoprotein or the effusion homogenate. Therefore, to produce a decrease in effusion viscosity in vivo, the concentration of mucolytic reaching the middle ear and the time it remains there are critical factors.  相似文献   
7.
This review discusses strategies that may address some of the limitations associated with replacing diseased or dysfunctional aortic valves with mechanical or tissue valves. These limitations range from structural failure and thromboembolic complications associated with mechanical valves to a limited durability and calcification with tissue valves. In pediatric patients there is an issue with the inability of substitutes to grow with the recipient. The emerging science of tissue engineering potentially provides an attractive alternative by creating viable tissue structures based on a resorbable scaffold. Morphometrically precise, biodegradable polymer scaffolds may be fabricated from data obtained from scans of natural valves by rapid prototyping technologies such as fused deposition modelling. The scaffold provides a mechanical profile until seeded cells produce their own extra cellular matrix. The microstructure of the forming tissue may be aligned into predetermined spatial orientations via fluid transduction in a bioreactor. Although there are many technical obstacles that must be overcome before tissue engineered heart valves are introduced into routine surgical practice these valves have the potential to overcome many of the shortcomings of current heart valve substitutes.  相似文献   
8.
目的 真核表达人呼吸道合胞病毒(human respiratory syncytial virus,SV)融合蛋白(fusion protein,),并完成蛋白纯化及纯度测定.方法 根据编码F蛋白的基因序列设计引物,CR方法扩增出3'端带His标签的F基因序列,克隆入pGEM-T-easy载体,经核酸序列分析后,进一步克隆到pcDNA3.1( )真核表达载体,限制性内切酶鉴定,用脂质体Lipofectamine2000转染COS-7细胞,2 h后再用Westem blot检测目的蛋白的表达.Ni柱亲和层析纯化COS-7细胞表达的F蛋白,高效毛细管电泳分析纯化后蛋白纯度.结果 核酸序列分析证实获得带His标签的RSV F基因序列,没有发生无义突变.转染COS-7细胞后,利用Western blot方法检测到F蛋白的特异性条带,纯度达99%以上.结论 初步建立了真核表达RSV F蛋白的纯化方法,为进一步优化RSV F蛋白制备条件及单克隆抗体及诊断试剂等研究奠定了基础.  相似文献   
9.
OBJECTIVES: Outpatient clinics are increasingly important in medical education. The effect of students on clinic times and patient satisfaction, as well as their own satisfaction, were studied. DESIGN: A prospective, non-randomized, controlled study using adult patient questionnaires, medical student questionnaires and clinic time sheets. SETTING: Two teaching hospital ENT clinics. SUBJECTS: Medical students and adult patients. RESULTS: Three hundred and twenty-five patient questionnaires were collected (77% response), including 135 student encounters. Students did not affect appointment durations (19 min +/- 0.48 (standard error)) except at centre B (35 min +/- 1.1, P < 0.0001) where patient numbers were cut for teaching. Patient satisfaction, generally high, was not affected by students, appointment duration or gender of doctor or patient. It was slightly higher in the lower social classes (rs = 0.20, P = 0. 003) and older patients (rs = 0.17, P = 0.002). Student acceptability scores were not affected by student numbers (up to four), social class or time spent alone with students. They were higher if time was spent alone with the doctor (75.3% +/- 4.9) than not (63.0% +/- 1.8, P = 0.024). Thirty-six per cent of patients preferred to have a student present; only 9% preferred not. Student satisfaction was higher at centre B (73.7% +/- 2.3) where appointments were longer and students spent more time alone with patients than centre A (64.3% +/- 2.3, P = 0.0052). CONCLUSIONS: Clinic appointments are not necessarily longer in the presence of students. When students have the chance to see patients alone during longer consultations, student satisfaction is higher. Patient satisfaction, generally high, is not altered by the presence of students, but patients given time alone with their doctor are more accepting of students. These findings have resource implications for the planning of NHS clinics in teaching hospitals.  相似文献   
10.
Influence of prednisolone on the secretion of mucin from the HT29‐MTX cell line Glucocorticoids have been used in the treatment of otitis media with effusion with promising but inconsistent results. The HT29‐MTX cell line is a completely differentiated and almost exclusively mucus‐secreting goblet cell line. To assess the potential of steroids in suppressing mucin secretion, we have studied the response of this cell culture to prednisolone. Confluent cell cultures were trypsinized, subcultured in six‐well plates and incubated with five doses of prednisolone from 10?3 M to 10?11 M and over a varying time course from 6 to 36 h. Analysis was performed using a monoclonal mouse antibody to human gastric mucin by dot‐blot ELISA. Prednisolone caused a consistent reduction in mucin production from this cell line. Increasing concentrations of prednisolone resulted in increasing suppression of MUC5AC secretion. There is a dose‐dependent suppression of mucin secretion by prednisolone, with a maximum effect of 21% over control seen at the highest steroid concentration used.  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