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   22080篇
  免费   1496篇
  国内免费   70篇
耳鼻咽喉   214篇
儿科学   529篇
妇产科学   386篇
基础医学   2973篇
口腔科学   695篇
临床医学   2185篇
内科学   5122篇
皮肤病学   251篇
神经病学   2089篇
特种医学   827篇
外国民族医学   1篇
外科学   2735篇
综合类   466篇
一般理论   19篇
预防医学   1752篇
眼科学   546篇
药学   1426篇
  1篇
中国医学   14篇
肿瘤学   1415篇
  2023年   97篇
  2022年   127篇
  2021年   351篇
  2020年   193篇
  2019年   322篇
  2018年   366篇
  2017年   280篇
  2016年   318篇
  2015年   395篇
  2014年   561篇
  2013年   913篇
  2012年   1217篇
  2011年   1280篇
  2010年   692篇
  2009年   715篇
  2008年   1276篇
  2007年   1389篇
  2006年   1390篇
  2005年   1403篇
  2004年   1296篇
  2003年   1233篇
  2002年   1215篇
  2001年   378篇
  2000年   334篇
  1999年   324篇
  1998年   305篇
  1997年   271篇
  1996年   249篇
  1995年   248篇
  1994年   211篇
  1993年   184篇
  1992年   249篇
  1991年   220篇
  1990年   245篇
  1989年   197篇
  1988年   222篇
  1987年   218篇
  1986年   193篇
  1985年   213篇
  1984年   190篇
  1983年   179篇
  1982年   222篇
  1981年   225篇
  1980年   172篇
  1979年   156篇
  1978年   114篇
  1977年   92篇
  1976年   86篇
  1974年   97篇
  1972年   81篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Technology is making the routine screening of symptoms and the measurement of quality of life (QoL) more feasible at the point of care. However, most existing symptom screening scales and QoL measures were not developed for clinical use and were not formatted and validated for administration through computerized mediums. The Cancer Care Monitor (CCM) is a symptom-based scale developed for administration on pen-based computers. This study is an initial evaluation of the reliability and validity of the CCM. Three samples of adult outpatients provided ratings on 38 physical, psychological, and functional oriented items of the CCM that comprise six symptom scales and one global QoL index. All additive scales are converted to normalized T scores. Reliability was examined through internal consistency and confirmatory factor analysis. Convergent and divergent validity were examined by comparing CMM scores to established measures of corresponding constructs and physician judgments. Alternative forms reliability was established by comparing paper and pencil administration with computer administration. Internal consistency reliability and factor analyses confirmed the structure of the CCM as comprising six primary symptom scales and one global QoL index. Internal consistency reliabilities ranged from 0.80 to 0.89. The pattern of correlations between CCM scales and established measures supported the convergent and divergent validity of the CCM scales. Alternate forms reliability based on paper and computer forms of the CCM scales was high. Patients indicated a preference for the computer-administered version. Results suggest that CCM items can be scored as a reliable and valid measure of constructs related to physical, psychological, and functional status, and global health-related QoL in adult cancer patients. Future studies should replicate and further evaluate the properties of the CCM, especially in relation to clinical utility.  相似文献   
992.
To evaluate the role of oral ketamine as an adjuvant to oral morphine in cancer patients experiencing neuropathic pain, 9 cancer patients (5 men, 4 women) taking maximally tolerated doses of either morphine, amitriptyline, sodium valproate, or a combination of these drugs for intractable neuropathic pain, and reporting a pain score of >6 on a 0-10 scale, were studied prospectively to evaluate analgesia and adverse effects. Ketamine in the dose of 0.5 mg/kg body weight three times daily was added to the existing drug regimen. Patients were taught to maintain a pain diary wherein they daily recorded their pain, sedation, and vomiting scores, and other side effects. A decrease of more than 3 from the baseline in the average pain score, or a score of < or =3 was taken as a successful response. Seven patients exhibited a decrease of more than 3. Four patients experienced nausea, of which one had vomiting. Two developed loss of appetite. Eight patients reported drowsiness during the first two weeks of therapy (P = 0.001), and this gradually improved over the next two weeks in 5 of these 8 patients. Three patients withdrew from the study, two owing to excessive sedation and another due to a "feeling of unreality." None of the patients reported visual or auditory hallucinations. This experience suggests that low dose oral ketamine is beneficial and effective in the management of intractable neuropathic pain in patients with advanced cancer. However, its utility is limited in some patients by the adverse effects that accompany its use.  相似文献   
993.
994.
The degree of the inoculum effect shown by the new beta-lactam antibiotics with Pseudomonas aeruginosa was investigated, and the antibiotics were divided into three groups based upon the observations. The group 1 antibiotics (cefotaxime, moxalactam, cefoperazone, azlocillin, piperacillin, and aztreonam) demonstrated a large inoculum effect, were poorly bactericidal, produced aberrant, elongated bacilli, and did not inhibit the increase in turbidity of high inocula during an 18-h incubation. The group 2 antibiotics (ceftazidime and ticarcillin) were slowly bactericidal, caused minimal formation of aberrant, elongated bacilli, and slowly decreased the turbidity of high inocula. The group 3 antibiotics (imipenem and gentamicin) were bactericidal, did not cause the formation of elongated bacilli, and decreased the turbidity of high inocula rapidly. Data are presented which suggest that the inoculum effect seen with the group 1 beta-lactam antibiotics is related to (i) the poor intrinsic antibactericidal activity of these antibiotics for P. aeruginosa at the inocula tested and (ii) failure of these antibiotics to inhibit the formation of aberrant and filamentous bacilli, which can result in increased bacterial mass and turbidity.  相似文献   
995.
996.
Hepatic and splenic sarcoidosis: Ultrasound and MR imaging   总被引:1,自引:0,他引:1  
Abdominal imaging studies may be performed for various indications in patients known to have sarcoidosis. To assess magnetic resonance imaging (MRI) and sonographic ability to detect abnormalities in sarcoidosis patients with abdominal involvement, a prospective study on 18 selected patients was performed. Besides organomegaly, when present, ultrasound demonstrated normal or increased hepatic parenchymal echogenicity, coarsening of the liver parenchyma with or without discrete nodules, focal calcifications, as well as contour irregularity. Splenic discrete nodules were seen on ultrasound in a single patient. Besides organomegaly, MRI abnormalities include abnormal hepatic signal intensity, discrete nodules, contour irregularity, spiculation of small hepatic vascular branches, and a high periportal signal intensity. MRI splenic abnormalities include contour irregularity, nodularity, and abnormal signal intensity.The data presented in this study reveals the spectrum of ultrasound and MRI findings in sarcoidosis patients with abdominal organ involvement, potentially enabling the evaluation of the severity of the disease. MRI appears more sensitive than ultrasound for study of abdominal sarcoidosis.  相似文献   
997.
998.
IntroductionOur institution is a 680-bed tertiary referral centre with broad medical and surgical subspecialty services. We retrospectively audited the pattern of inpatient consultations from all specialities within our institution to the urology department over a 1-year period.MethodsAll consultations to the urology service were identified from our computerised inpatient consultation system from July 2010 to June 2011. Follow up data on investigations, interventions and subsequent outpatient appointments were also identified by review of individual patient discharge letters.ResultsSeven hundred and twenty five inpatient consultations were received over the period. The male to female ratio was 7:3. Mean age of patients was 66 (15–96) years. Seventy three percent of referrals were from medical sub-specialities, most commonly nephrology (17%), gastroenterology (11%) and respiratory medicine (9%). The remainder were from general surgery (16%) and other surgical sub specialities (11%). Interns (66%) and senior house officers (SHO) (28%) communicated the majority of consults. Male lower urinary tract/benign prostate related issues resulted in 25% of all consultations. Less than half of consults (47%) resulted in interventions initiated by urology, most commonly of which were catheter insertions (48%) and endoscopic procedures (35%). Only 43% of consultations were followed up in the outpatients setting.ConclusionsInpatient consultations constitute a significant workload for urology services. The majority of these referrals did not require any urological intervention and could have been seen routinely in the outpatient setting. Providing structured referral guidelines and achieving better communication with referring teams may help to optimise this service.  相似文献   
999.
Krassioukov A, Eng JJ, Warburton DE, Teasell R, Spinal Cord Injury Rehabilitation Evidence Research Team. A systematic review of the management of orthostatic hypotension after spinal cord injury.

Objective

To review systematically the evidence for the management of orthostatic hypotension (OH) in patients with spinal cord injuries (SCIs).

Data Sources

A key word literature search was conducted of original and review articles as well as practice guidelines using Medline, CINAHL, EMBASE, and PsycInfo, and manual searches of retrieved articles from 1950 to July 2008, to identify literature evaluating the effectiveness of currently used treatments for OH.

Study Selection

Included randomized controlled trials (RCTs), prospective cohort studies, case-control studies, pre-post studies, and case reports that assessed pharmacologic and nonpharmacologic intervention for the management of OH in patients with SCI.

Data Extraction

Two independent reviewers evaluated the quality of each study, using the Physiotherapy Evidence Database score for RCTs and the Downs and Black scale for all other studies. Study results were tabulated and levels of evidence assigned.

Data Synthesis

A total of 8 pharmacologic and 21 nonpharmacologic studies were identified that met the criteria. Of these 26 studies (some include both pharmacologic and nonpharmacologic interventions), only 1 pharmacologic RCT was identified (low-quality RCT producing level 2 evidence), in which midodrine was found to be effective in the management of OH after SCI. Functional electrical stimulation was one of the only nonpharmacologic interventions with some evidence (level 2) to support its utility.

Conclusions

Although a wide array of physical and pharmacologic measures are recommended for the management of OH in the general population, very few have been evaluated for use in SCI. Further research needs to quantify the efficacy of treatment for OH in subjects with SCI, especially of the many other pharmacologic interventions that have been shown to be effective in non-SCI conditions.  相似文献   
1000.
Krassioukov A, Warburton DE, Teasell R, Eng JJ, Spinal Cord Injury Rehabilitation Evidence Research Team. A systematic review of the management of autonomic dysreflexia after spinal cord injury.

Objective

To review systematically the clinical evidence on strategies to prevent and manage autonomic dysreflexia (AD).

Data Sources

A key word search of several databases (Medline, CINAHL, EMBASE, and PsycINFO), in addition to manual searches of retrieved articles, was undertaken to identify all English-language literature evaluating the efficacy of interventions for AD.

Study Selection

Studies selected for review included randomized controlled trials (RCTs), prospective cohort studies, and cross-sectional studies. Treatments reviewed included pharmacologic and nonpharmacologic interventions for the management of AD in subjects with spinal cord injury. Studies that failed to assess AD outcomes (eg, blood pressure) or symptoms (eg, headaches, sweating) were excluded.

Data Extraction

Studies were critically reviewed and assessed for their methodologic quality by 2 independent reviewers.

Data Synthesis

Thirty-one studies were assessed, including 6 RCTs. Preventative strategies to reduce the episodes of AD caused by common triggers (eg, urogenital system, surgery) primarily were supported by level 4 (pre-post studies) and level 5 (observational studies) evidence. The initial acute nonpharmacologic management of an episode of AD (ie, positioning the patient upright, loosening tight clothing, eliminating any precipitating stimulus) is supported by clinical consensus and physiologic data (level 5 evidence). The use of antihypertensive drugs in the presence of sustained elevated blood pressure is supported by level 1 (prazosin) and level 2 evidence (nifedipine and prostaglandin E2).

Conclusions

A variety of options are available to prevent AD (eg, surgical, pharmacologic) and manage the acute episode (elimination of triggers, pharmacologic); however, these options are predominantly supported by evidence from noncontrolled trials, and more rigorous trials are required.  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