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   392485篇
  免费   26142篇
  国内免费   9190篇
耳鼻咽喉   4438篇
儿科学   10671篇
妇产科学   8635篇
基础医学   33667篇
口腔科学   9033篇
临床医学   42120篇
内科学   48069篇
皮肤病学   5313篇
神经病学   23547篇
特种医学   9310篇
外国民族医学   38篇
外科学   40359篇
综合类   58187篇
现状与发展   15篇
一般理论   37篇
预防医学   40416篇
眼科学   6811篇
药学   36441篇
  444篇
中国医学   34311篇
肿瘤学   15955篇
  2023年   6182篇
  2022年   10999篇
  2021年   15173篇
  2020年   14059篇
  2019年   19727篇
  2018年   17377篇
  2017年   14488篇
  2016年   12037篇
  2015年   11306篇
  2014年   22631篇
  2013年   25229篇
  2012年   21028篇
  2011年   22835篇
  2010年   18355篇
  2009年   16847篇
  2008年   16448篇
  2007年   16952篇
  2006年   14890篇
  2005年   13015篇
  2004年   10631篇
  2003年   9415篇
  2002年   7465篇
  2001年   6784篇
  2000年   5587篇
  1999年   4891篇
  1998年   4053篇
  1997年   3910篇
  1996年   3416篇
  1995年   3283篇
  1994年   3060篇
  1993年   2497篇
  1992年   2505篇
  1991年   2147篇
  1990年   1998篇
  1989年   1741篇
  1988年   1583篇
  1987年   1357篇
  1986年   1335篇
  1985年   4131篇
  1984年   5111篇
  1983年   3531篇
  1982年   4051篇
  1981年   3745篇
  1980年   3360篇
  1979年   3065篇
  1978年   2664篇
  1977年   2032篇
  1976年   2258篇
  1975年   1715篇
  1974年   1487篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.

Background

Controversy continues as to whether single-incision laparoscopic cholecystectomy, with the somewhat larger incision at the umbilicus, may lead to a worse postoperative quality of life and more pain compared with the more classic 4-port laparoscopic cholecystectomy. The aim of this study was to compare single-incision and 4-port laparoscopic cholecystectomy from the perspective of quality of life.

Methods

This study was a multicenter, parallel-group, open-label, randomized clinical trial. A total of 120 patients who were scheduled to undergo elective cholecystectomy were randomly assigned 1:1 into the single-incision laparoscopic cholecystectomy or the 4-port laparoscopic cholecystectomy group and then assessed continuously for 2 weeks during the postoperative period. The primary outcome was quality of life, defined as the time to resume normal daily activities. Postoperative pain was also assessed. To explore the heterogeneity of treatment effects, we assessed the interactions of sex, age, and working status on recovery time.

Results

A total of 58 patients in the single-incision group and 53 in the 4-port group (n?=?111, 47 male, mean age 57 years) were analyzed. The mean time to resume daily activities was 10.2 days and 8.8 days, respectively, for single-incision and 4-port laparoscopic cholecystectomy (95% confidence interval –0.4 to 3.2, P?=?.12). Similarly, the time to relief from postoperative pain did not differ significantly between the groups. Statistically insignificant but qualitative interactions were noted; in the subgroups of women, full-time workers, and patients younger than 60 years, recovery tended to be slower after single-incision laparoscopic cholecystectomy.

Conclusion

Postoperative quality of life did not differ substantially between single-incision laparoscopic cholecystectomy and 4-port laparoscopic cholecystectomy. Patients younger than 60 years, women, and full-time workers tended to have a somewhat slower recovery after single-incision laparoscopic cholecystectomy.  相似文献   
32.
Study objectivesTo analyze the association between sleep-related symptoms and sleep length in parents and their children in relation to other risk factors in both generations.MethodThe participants were parents (n = 5,855, age 54.3 ± 6.5 years, 45.2% men) who participated in the community-based Respiratory Health in Northern Europe (RHINE) study and one random member of their adult offspring (n = 5,855, age 30.2 ± 7.7 years, 41.5% men) who participated in the Respiratory Health in Northern Europe, Spain and Australia (RHINESSA) study. Both generations responded to identical questionnaires on sleep symptoms, including difficulty initiating sleep (DIS), difficulty maintaining sleep (DMS), early morning awakening (EMA), snoring, nocturnal sweating, nocturnal gastroesophageal reflux (nGER), sleep time and excessive daytime sleepiness (EDS). Insomnia was defined as either, or both, DIS and DMS in combination with EDS.ResultsAll sleep variables except nocturnal sweating were more common in offspring whose parents had reported the same symptom. After adjusting for age, gender, BMI, smoking, physical activity, education, center and parents' total number of children, there were independent associations between sleep symptoms in parents and offspring for DIS (adj. OR, 95% CI: 1.52, 1.20–1.93), DMS (1.34, 1.15–1.56), snoring (1.45, 1.15,1.83), nGER (1.65, 1.15–2.37), insomnia (1.39, 1.13–1.73), short sleep time (<6 h/night) (2.51, 1.72–3.68) and EDS (1.48, 1.26,1.72). There were no independent relationships between symptoms in parents and offspring for EMA, nocturnal sweating or long sleep time (>9 h/night).ConclusionThe familiar aggregation of many sleep disturbances was not explained by investigated lifestyle and environmental factors. This supports a heritable factor in sleep problems.  相似文献   
33.
Quality of life (QoL) is an important consideration among asthma sufferers. The Pediatric Asthma Quality of Life Questionnaire (PAQLQ) is one of the most widely used instruments for measuring health-related QoL in children with asthma. The standardized version of PAQLQ contains 23 questions in three domains, i.e., activity limitation, symptoms and emotional function. The objective of this study was to validate the Thai-translated version of the PAQLQ. The study design consisted of a five-week single cohort study. Patients recorded symptoms, and peak expiratory flow rate (PEFR) each morning and evening during the first and fifth week of the study in asthma diary. At each clinic visit, a trained-interviewer administered the PAQLQ and performed spirometric measurements. Fifty-one children, ages between 7 and 17 yr participated in the study. Scores from the asthma diary were used to classify patients into stable vs. unstable groups. The construct validity of the questionnaire was confirmed in both cross-sectional and longitudinal studies by demonstrating correlations between various PAQLQ domains with clinical asthma parameters (asthma diary, beta-agonist use and PEFR). There was high internal consistency for scores of the three domains (Cronbach's alpha-coefficient = 0.83-0.95). For those with stable asthma, the reliability of PAQLQ was good for the rating scale (intra-class correlation coefficient--ICC = 0.84) and for total score (alpha = 0.97) indicating high reproducibility of the PAQLQ. The significant difference of changes QoL scores between stable and unstable groups was observed in all domains. We conclude that the Thai version of PAQLQ is valid and reliable for implementing in Thai children with asthma.  相似文献   
34.
The Present and Future of Clinical Psychology in Private Practice   总被引:1,自引:0,他引:1  
This article discusses clinical psychologists' current concerns, challenges, and opportunities in private practice. The future of clinicians in independent practice is presented within two paradigms, namely, psychology as a health profession, and psychology as life enhancement. Finally, the author argues that psychotechnology, corporate clinical psychology, and psychology as life enrichment will evolve within the future of clinical psychological independent practice.  相似文献   
35.
We have carried out a prospective randomised, single blind clinical trial to investigate the effect of continuous passive motion on range of knee flexion, lack of extension, pain levels and analgesic use after total knee replacement surgery. 85 subjects were randomly allocated to control or study group. All subjects followed the existing rehabilitation protocol, which permits immediate active range of motion exercises and mobilisation with the study group using continuous passive motion for 1 h, twice a day. Outcome measures employed were range of motion, pain assessed on a visual analogue scale and analgesic use according to the WHO ladder. Blinded evaluation was carried out preoperatively, at time of discharge from hospital, 6 weeks, 6 and 12 months postoperation. No significant difference was observed between groups at all time intervals for each outcome variable using Wilcoxon Rank sum tests. The results substantiate previous findings that short duration continuous passive motion following total knee arthroplasty does not influence outcome of range of motion or reported pain.  相似文献   
36.
Here we report how the different types of regional muscle involvement, i.e. bulbar, ocular or generalized, in patients with myasthenia gravis (MG) influence the mental aspects of quality of life. Clinical examination according to Osserman was performed in 48 MG patients (45 women, three men; mean age 54, SD 12 years). Each patient was at the time for clinical evaluation asked to fill out the disease-specific Myasthenia Gravis Questionnaire (MGQ) and the Short-Form 36-item questionnaire for health survey (SF-36) as patient-oriented tools. We related the regional domains (generalized domain, bulbar domain and ocular domain) of the MGQ and the clinical findings, respectively, with mental quality of life as assessed by SF-36. Bulbar and generalized involvement results in impairment of mental aspects of quality of life, whereas ocular involvement does not.  相似文献   
37.
Using the SF-12 to measure physical and mental functioning, the authors examine the intra-individual changes in health-related quality of life (HRQOL) 6 months post-discharge for depressed older adults. In addition, they examine three sets of predictors that might influence these changes. The sample of depressed older adults was recruited from an inpatient geropsychiatry unit. Although their physical and mental health scores on the SF-12 were lower than comparable norms, the sample showed an average increase in their mental functioning but a decrease in the physical functioning over the 6 months. Negative life-events were significant predictors of people who reported no change in their mental health functioning and decreases in their physical health functioning. Interestingly, those who experienced positive life events were more likely to report declines and younger participants were more likely to report no change in their physical functioning. The findings indicate that the effects of depression on HRQOL can have enduring effects on a sample of previously hospitalized older adults. The significance of life event changes might signify the importance of taking into account non-traditional areas of medical interventions. Further, the findings indicate the usefulness of the SF-12 quantifying HRQOL outcomes.  相似文献   
38.
肝癌间质及癌旁病变的病理分析   总被引:2,自引:0,他引:2  
目的 研究肝癌间质及癌旁病变的临床病理意义。方法 在 2 0例肝癌组织标本中取 45个癌结节 ,分别在癌结节中间、癌旁肝组织等部位取组织 4块 ,连续切片 ,显微镜下观察。结果  19个结节有完整窦内皮细胞围绕癌巢 ,其中癌结节肉眼小于3cm者 13个 ,大于 3cm者 6个。 2 6个癌结节无完整窦内皮细胞围绕癌巢 ,其中癌结节直径大于 3cm者 2 4个 ,小于 3cm者 2个。2 0例中有 13例合并肝硬化 ,17例有乙型肝炎病毒感染和HBsAg阳性。 结论 病理连续切片 ,显微镜下观察肝癌间质及癌旁病变是预测肝癌患者预后的重要病理学指标  相似文献   
39.
Intraductal papillary mucinous tumor (IPMT) of the pancreas is characterized by slow growth and a relatively favorable prognosis, however, invasive cancer originating in an IPMT is associated with a poor prognosis. Although various parameters in imaging modalities have been advocated to differentiate between benign IPMN and malignant ones, it is not easy to obtain definite diagnosis based on these parameters. Peroral pancreatoscopy (POPS) allows a clear and direct visualization of the pancreatic duct, providing useful information regarding tumor nature in IPMT. The authors have studied the usefulness of POPS in the diagnosis of IPMT. Nevertheless, its usefulness is not necessarily widely accepted and the significance of POPS is still controversial. In this review, the authors intended to address the diagnostic value of POPS and to clarify its role in the diagnosis of IPMT. The authors think treatment of IPMT can be improved by introducing POPS because the determination of surgical procedure as well as the area of resection based on the preoperative diagnosis of the involvement of the main pancreatic duct and branch duct is inevitable.  相似文献   
40.
皮质发育障碍模型的建立及其致痫敏感性的研究   总被引:1,自引:0,他引:1  
目的:建立皮质发育障碍模型,探讨皮质发育障碍模型的敏感性。方法:在SD大鼠孕17d腹腔注入1,3-二氯乙烯-亚硝基脲(BCNU)制作皮质发育障碍模型;Nissl染色观察P60d仔鼠病理变化;选取P60d雄性仔鼠,腹腔注射氯化锂-毛果芸香碱,分别比较两组大鼠癫发生的潜伏期、持续状态时间和死亡率。结果:同龄仔鼠脑组织湿重实验组比对照组显著减轻(P<0.01);Nissl染色显示皮质变薄、皮质层次紊乱、海马区域异位细胞异常聚集;有皮质发育障碍的仔鼠注射氯化锂-毛果芸香碱后,癫发生的潜伏期显著缩短(P<0.01),癫持续状态时间延长(P<0.01),死亡率显著升高(P<0.05)。结论:BCNU致皮质发育障碍模型具有癫易感性。  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