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   8846篇
  免费   555篇
  国内免费   91篇
耳鼻咽喉   114篇
儿科学   110篇
妇产科学   168篇
基础医学   771篇
口腔科学   395篇
临床医学   757篇
内科学   1019篇
皮肤病学   96篇
神经病学   260篇
特种医学   490篇
外科学   2014篇
综合类   933篇
一般理论   1篇
预防医学   668篇
眼科学   65篇
药学   1069篇
  12篇
中国医学   335篇
肿瘤学   215篇
  2024年   12篇
  2023年   211篇
  2022年   330篇
  2021年   579篇
  2020年   474篇
  2019年   410篇
  2018年   397篇
  2017年   359篇
  2016年   336篇
  2015年   330篇
  2014年   640篇
  2013年   755篇
  2012年   451篇
  2011年   536篇
  2010年   408篇
  2009年   382篇
  2008年   369篇
  2007年   363篇
  2006年   317篇
  2005年   254篇
  2004年   219篇
  2003年   175篇
  2002年   135篇
  2001年   120篇
  2000年   93篇
  1999年   111篇
  1998年   80篇
  1997年   65篇
  1996年   65篇
  1995年   62篇
  1994年   48篇
  1993年   37篇
  1992年   24篇
  1991年   32篇
  1990年   32篇
  1989年   20篇
  1988年   27篇
  1987年   25篇
  1986年   22篇
  1985年   28篇
  1984年   27篇
  1983年   14篇
  1982年   28篇
  1981年   10篇
  1980年   12篇
  1979年   18篇
  1978年   8篇
  1977年   10篇
  1976年   9篇
  1974年   6篇
排序方式: 共有9492条查询结果,搜索用时 31 毫秒
891.
Adipocyte-fatty acid binding protein (A-FABP) is a biomarker of adiposity and metabolic syndrome. The aim of our work was to investigate the effect of weight reduction on serum A-FABP value. In the study, we analyzed a group of 189 probands suffering from obesity (102 women and 87 men; aged 57.3+/-12 years) initially, after a 3-month low-fat diet and once again 3 months after the termination of the diet for serum A-FABP, insulin, glucose, total cholesterol, HDL-cholesterol, LDL-cholesterol, and triglycerides. Basal biomarker concentrations were typical of the metabolic syndrome, and moreover A-FABP correlated with Quicki and BMI. We observed a reduction in BMI in 145 subjects who were divided into two subgroups: A-with persistent BMI reduction even after 6 months, B-with BMI reduction after 3 months and its regress after 6 months. Individuals with rise or no BMI difference were signed as subgroup C. In subgroup A, A-FABP level increased and returned to the earlier level (42.3 vs 68.3 vs 37.1 microg/l) and correlated with the markers of the metabolic syndrome. In subgroup B, A-FABP level increased less significantly, however elevated A-FABP level persisted for 6 months (41.9 vs 53.6 vs 50.7 microg/l). Subgroup C (n=54) showed no difference in A-FABP after 3-month diet and after next 3 months. The A-FABP value correlated with the some components of the metabolic syndrome. In conclusion, we describe that serum A-FABP might be a prognostic marker of body weight loss suggesting a preventive therapeutic intervention.  相似文献   
892.
PURPOSE: To provide nurse practitioners (NPs) with clinical research about Mindfulness-Based Stress Reduction (MBSR) and demonstrate its usefulness for reducing stress in a variety of populations. DATA SOURCES: A literature review was conducted using the following databases: EBSCO, Cinahl, Pschyline, and Medline. English language articles published between 2000 and 2006 in peer-reviewed journals were reviewed. Search terms "mindfulness,"meditation," and "stress" were used. Additional information was obtained through select, reputable Internet sites. CONCLUSIONS: MBSR is an effective treatment for reducing stress and anxiety that accompanies daily life and chronic illness. MBSR is also therapeutic for healthcare providers, enhancing their interactions with patients. No negative side effects from MBSR have been documented. IMPLICATIONS FOR PRACTICE: MBSR is a safe, effective, integrative approach for reducing stress. Patients and healthcare providers experiencing stress or stress-related symptoms benefit from MBSR programs. NPs can safely and effectively use this intervention in a variety of patient populations.  相似文献   
893.
OBJECTIVE: Gastric inflation (GI) is a significant issue when ventilation is performed on unprotected airways. DESIGN: Experimental analysis on the respiratory effects of hose extended bag-valve ventilation devices designed to reduce inspiratory pressure and flow. SETTING: Laboratory with lung/oesophageal sphincter simulator and pressure-flow-volume analyser. Lung compliance: 300ml/kPa, airway resistance: 0.5kPa/l/s. Lower oesophageal sphincter pressure (LOSP): 0.5kPa. INTERVENTIONS: Bag-valve ventilation of lung simulator. Twelve academic dental staff members used four devices: Ambu Mark III attached to either a reservoir bag (R) or a pressure relief valve (SV), SMART BAG (SB), and Easy Grip (EG) as control. RESULTS: After Bonferroni correction (p-level of significance 0.0083) for multiple comparisons, no evidence of difference between inspiratory tidal volumes (TVIN) administered by use of R (median 137ml) and SB (149ml) was found. Differences in TVIN were only detected between R and SV (188ml) (p=0.002). Only a trend towards TVIN differences between SB and R in comparison to EG (195ml) was found (p=0.009). Distributions of peak pressures differed when R (median 0.7kPa) and SV (1.0kPa) (p=0.006) or SB (0.7kPa) and SV (p=0.002) were compared. Peak inspiratory flow rates differed between EG (median 59l/min) and R (32l/min) as well as SB (42l/min) and between SB and SV (50l/min) (all with p=0.001). GI was lowest by use of R (median 103ml) compared to all other devices (EG: 518ml, SV: 394ml, SB: 271ml) (p=0.001). The areas under the pressure/flow over time curves were larger during SB compared to R ventilation. Mean airway pressures were significantly lower by use of R (0.1kPa) compared to SB (0.3kPa) (p<0.008). CONCLUSION: Lowering GI by pressure-flow reduction may result in lower TV depending on the device used. Lowest GI resulted from R ventilation. This may be explained by the specific pressure/time or flow/time patterns achieved by use of this device.  相似文献   
894.

Introduction

The purpose of this study was to retrospectively evaluate the effect of the Dynasplint® Trismus System (DTS; Dynasplint Systems Inc, Severna Park, Md, USA) for patients who were recently diagnosed with trismus following radiation therapy, dental treatment, oral surgery, or following a neural pathology such as a stroke.

Methods

We reviewed 48 patient histories (treated in 2006–2007), and divided into 4 cohort groups (radiation therapy for head/neck cancer, dental treatment, oral surgery, or stroke), to measure the efficacy of this treatment’s modality. Patients were prescribed the DTS after diagnosis of trismus based on examination that showed <40 mm maximal interincisal distance. The DTS uses low-load, prolonged-duration stretch with replicable, dynamic tension to achieve longer time at end range (of motion). Each patient used this device for 20–30 min, 3 times per d.

Results

This cohort case series showed that there was a statistically significant difference within all patient groups (P<0.0001; t=10.3289), but there was not a significant difference between groups (P=0.374).

Conclusion

The biomechanical modality of DTS with a low-load, prolonged-duration stretch was attributed to the success in reducing contracture in this study. This improved range of motion, allowing patients to regain the eating, hygiene and speaking patterns they had before developing trismus.
  相似文献   
895.
BACKGROUND: Chronic fatigue syndrome (CFS) is associated with a high use of health care services. To reduce the related costs for patients and society, it will be useful to know which factors determine CFS patients' amount of health care use. Little is known, however, about these factors. METHOD: The present study retrospectively performed a cross-sectional analysis to investigate the possible factors determining CFS patients' health care use. A total of 263 CFS patients, derived from two subgroups (149 from tertiary care and 114 from primary/secondary care), participated. Health care use was measured with a questionnaire asking details on consumption over the past 6 months. Fatigue severity and physical functioning were measured with the subscale Experienced Fatigue of the Checklist Individual Strength (CIS-20) and the subscale Physical Functioning of the SF-36, respectively. Multiple regression analysis, T-tests, and chi(2) tests were performed. RESULTS: The regression analysis revealed that, after controlling for patient characteristics (explaining 13%), fatigue factors added 4% predictive value and certain perpetuating factors of fatigue, including focus on bodily symptoms and attributions of fatigue, added another 5%. The analysis of subgroups revealed that, compared to the tertiary care population, fewer patients from primary/secondary care had visited a medical specialist (50% vs. 71%), used antidepressants (16% vs. 25%) and tranquilizers (3% vs. 18%), and had spent a night in hospital (7% vs. 10%). However, overall costs of health care between these subgroups did not differ. CONCLUSIONS: This study showed that illness duration, physical impairment due to fatigue, and psychological perpetuating factors of fatigue do determine the variance in CFS patients' health care use. These results give clear directions for treating CFS patients and managing health care for CFS.  相似文献   
896.
The Nd:YAG laser efficacy associated with conventional treatment for bacterial reduction has been investigated throughout literature. The purpose of this study was to evaluate the bacterial reduction after Nd:YAG laser irradiation associated with scaling and root planning in class II furcation defects in patients with chronic periodontitis. Thirty-four furcation lesions were selected from 17 subjects. The control group received conventional treatment, and the experimental group received the same treatment followed by Nd:YAG laser irradiation (100 mJ/pulse; 15 Hz; 1.5 W, 60 s, 141.5 J/cm2). Both treatments resulted in improvements of most clinical parameters. A significant reduction of colony forming unit (CFU) of total bacteria number was observed in both groups. The highest reduction was noted in the experimental group immediately after the treatment. The number of dark pigmented bacteria and the percentage of patients with Porphyromonas gingivalis, Prevotella intermedia, and Actinobacillus actinomycetemcomitans reduced immediately after the treatment and returned to values close to the initial ones 6 weeks after the baseline for both groups. The Nd:YAG laser associated with conventional treatment promoted significant bacterial reduction in class II furcation immediately after irradiation, although this reduction was not observed 6 weeks after the baseline.  相似文献   
897.
Nipple necrosis is a potential complication of breast reduction and mastopexy procedures that can be prevented if the surgeon is acquainted with the arterial blood supply to the breast, particularly the nipple–areolar complex (NAC). A review of the latest research on this with its clinical application is given.  相似文献   
898.

Background:

The treatment of displaced intracapsular femoral neck fracture is still an unsolved problem. Non-union and avascular necrosis are the two main complications of this fracture, especially if patient presents late. Muscle pedicle bone grafting has been advocated to provide additional blood supply. We present analysis of our 32 cases of displaced femoral neck fracture treated by internal fixation and quadratus femoris based muscle pedicle bone grafting.

Materials and Methods:

Open reduction and internal fixation with muscle pedicle grafting was done in 32 patients. The age of patients varied from 14-62 years (average age 45 years) with male to female ratio of 13:3. Twenty-nine fractures were more than three weeks old. All the cases were treated by Meyers'' procedure. The fracture was internally fixed after open reduction and then a muscle pedicle graft was applied. It was supplemented by cancellous bone graft in seven cases. Fixation was done by parallel cancellous lag screws (n = 19), crossed Garden''s screws (n = 7), parallel Asnis screws (n = 5) and Moore''s pin (n = 1).Quadratus femoris muscle pedicle graft was used in 32 cases. In the initial 12 cases the graft was fixed with circumferential proline sutures, but later, to provide a secure fixation, the graft was fixed with a cancellous screw (n = 20). Postoperative full weight bearing was deferred to an average of 10 weeks.

Results:

Union was achieved in 26/29 (89.65%) cases which could be followed for an average period of 3.4 years, (2-8.5 years) with good functional results and had the ability to squat and sit cross-legged. Results were based on hip rating system given by Salvatti and Wilson. The results were excellent in 15 cases, good in four cases, fair in four cases and poor in six cases. Complications were avascular necrosis (n = 2), transient foot drop (n = 2), coxa-vara (n = 1) and temporary loss of scrotal sensation (n = 1).

Conclusion:

Muscle pedicle bone grafting with internal fixation is a viable treatment option in displaced femoral neck fractures with late presentation.  相似文献   
899.
Ring D 《Injury》2008,39(12):1329-1337
Unstable, displaced fractures of the radial head nearly always occur in association with other fractures or ligament injuries. Radiocapitellar contact is important to elbow and forearm stability and should be restored in the context of such injuries. Open reduction and internal fixation of the radial head is associated with early failure, nonunion, and poor forearm motion. Replacement of the radial head with a metal prosthesis may be preferable. The major pitfall of a metal prosthesis is insertion of a prosthesis that is too large in longitudinal length, which can lead to subluxation, capitellar wear, stiffness, and pain. When this is avoided the medium- and long-term results are satisfactory with no major problems identified.  相似文献   
900.
We report an unusual case of a chronic prosthetic dislocation that was caused by the buttonholing of a prosthetic femoral head by anterior soft tissue, which impeded reduction. A surprisingly good functional result was achieved by an open reduction and revision operation on a 56-year-old man, who had a chronic dislocation of a total hip prosthesis. Successful treatment with open reduction of a chronic proximal dislocation after total hip arthroplasty has not been reported previously in the literature.  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