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   3528篇
  免费   204篇
  国内免费   33篇
耳鼻咽喉   29篇
儿科学   167篇
妇产科学   126篇
基础医学   389篇
口腔科学   157篇
临床医学   326篇
内科学   768篇
皮肤病学   35篇
神经病学   113篇
特种医学   80篇
外科学   758篇
综合类   76篇
一般理论   2篇
预防医学   179篇
眼科学   85篇
药学   251篇
中国医学   30篇
肿瘤学   194篇
  2024年   3篇
  2023年   35篇
  2022年   91篇
  2021年   120篇
  2020年   93篇
  2019年   115篇
  2018年   136篇
  2017年   90篇
  2016年   114篇
  2015年   122篇
  2014年   156篇
  2013年   201篇
  2012年   284篇
  2011年   296篇
  2010年   149篇
  2009年   134篇
  2008年   221篇
  2007年   200篇
  2006年   190篇
  2005年   195篇
  2004年   176篇
  2003年   143篇
  2002年   129篇
  2001年   48篇
  2000年   42篇
  1999年   39篇
  1998年   24篇
  1997年   23篇
  1996年   17篇
  1995年   15篇
  1994年   14篇
  1993年   10篇
  1992年   11篇
  1991年   8篇
  1990年   12篇
  1989年   10篇
  1988年   9篇
  1987年   6篇
  1986年   13篇
  1985年   11篇
  1984年   6篇
  1983年   6篇
  1982年   7篇
  1981年   6篇
  1980年   3篇
  1978年   8篇
  1977年   3篇
  1976年   5篇
  1974年   3篇
  1969年   3篇
排序方式: 共有3765条查询结果,搜索用时 15 毫秒
71.
72.
The quality of care delivered to 74 patients undergoing orthognathic surgery was assessed using a patient satisfaction questionnaire and data collected from hospital case records. Surgical complications, hospital services, patient satisfaction, and impact on quality of life, were the main aspects considered. The majority of patients reported that their treatment objectives had been achieved and that they were satisfied with the quality of care provided. The main concern of the patients regarding the clinic was the waiting time before an appointment could be offered. Eating and breathing difficulties and low mood after surgery were the main reported complications. Sixty-three patients experienced post-operative weight loss. The importance of a nutritious, high calorie soft diet should be emphasised and the use of menthol inhalations following maxillary osteotomies should be considered more frequently. Clinicians should be aware of post-operative low mood, which may require psychological support. We developed a sensitive assessment battery with comprehensive parameters to audit quality of orthognathic surgery service, and recommend that a similar approach should be considered by teams which undertake management of orthognathic patients.  相似文献   
73.
Purpose: To identify the oral health attitudes/behaviour among dental students in Jordan, and analyse the variations in oral health attitudes based on gender and level of education. Materials and Methods: Out of the 653 registered dental students at the faculty of dentistry, 580 students (455 females and 125 males, mean age = 20.1 ± 1.6 years) participated in the study (response rate 89%). The Hiroshima University-Dental Behavioural Inventory (HU-DBI) was used to assess oral heath attitudes and behaviour of the participants. Data were analysed using the chi-square test, and statistical significance was set at P < 0.05. Results: Females had better oral health attitudes and behaviour, especially towards visiting the dentist, toothbrushing habits and oral hygiene practice (P < 0.05). Also, students from the higher years had better oral health attitudes, behaviour and knowledge, especially towards gingival health, oral hygiene practice, toothbrushing and visiting the dentist (P < 0.05). Conclusion: Dental students in Jordan had poor oral health attitudes and behaviour. Females had better oral health knowledge, attitudes and behaviour than males. With increasing years of study, some aspects of dental students' oral health behaviour and attitudes improved. However, this improvement was limited and students should be encouraged to become an example of oral health for their society. Better comprehensive dental education with early exposure to dental health and prevention was suggested to improve dental students' oral health attitudes and behaviour.  相似文献   
74.

PURPOSE

To compare the changes in the occlusal vertical dimension, activity of masseter muscles and biting force after insertion of immediate denture constructed with conventional, tooth-supported and Implant-supported immediate mandibular complete denture.

MATERIALS AND METHODS

Patients were selected and treatment was carried out with all the three different concepts i.e, immediate denture constructed with conventional (Group A), tooth-supported (Group B) and Implant-supported (Group C) immediate mandibular complete dentures. Parameters of evaluation and comparison were occlusal vertical dimension measured by radiograph (at three different time intervals), Masseter muscle electromyographic (EMG) measurement by EMG analysis (at three different positions of jaws) and bite force measured by force transducer (at two different time intervals). The obtained data were statistically analyzed by using ANOVA-F test at 5% level of significance. If the F test was significant, Least Significant Difference test was performed to test further significant differences between variables.

RESULTS

Comparison between mean differences in occlusal vertical dimension for tested groups showed that it was only statistically significant at 1 year after immediate dentures insertion. Comparison between mean differences in wavelet packet coefficients of the electromyographic signals of masseter muscles for tested groups was not significant at rest position, but significant at initial contact position and maximum voluntary clench position. Comparison between mean differences in maximum biting force for tested groups was not statistically significant at 5% level of significance.

CONCLUSION

Immediate complete overdentures whether tooth or implant supported prosthesis is recommended than totally mucosal supported prosthesis.  相似文献   
75.
76.
To investigate the role of high-frequency ultrasonography in the diagnosis of calcium pyrophosphate dihydrate (CPPD) calcifications, in the most commonly affected joints in CPPD disease. Sixty patients with knee effusion were included in the study. All patients underwent musculoskeletal ultrasonography (on the shoulder, elbow, wrist, and knee joints), radiological examination of the sites examined by US, and synovial fluid analysis (using polarized light microscopy). Out of 60 patients with knee effusion, ultrasonographic calcifications (knees, shoulders, and wrists) were present in 38 patients (63.3%) and out of those patients; 32 had calcification characteristic of CPPD crystals deposition (hyperechoic deposits) in the knee and wrist joints. Pattern II (punctate pattern) was the most common pattern of calcification. It was present in all patients who had wrist calcification (18 patients) and in the knee in either alone (21 patients) or in association with pattern I (hyperechoic band) and/or pattern III (hyperechoic nodular or oval deposits) (9 patients). The sensitivity of ultrasonography for the detection of calcification was 84.2% while that of plain radiography was 13.2%, the specificity of both ultrasonography and plain radiography for the detection of calcification was 100%, and ultrasonography is valuable for diagnosing articular chondrocalcinosis via the detection of calcifications within the joint cartilage and fibrocartilage. Both sensitivity and specificity are high for detecting CPPD deposits.  相似文献   
77.
Current oral cholera vaccines induce lower levels of protective efficacy and shorter durations of protection in young children than in adults. Immunity against cholera is serogroup specific, and immune responses to Vibrio cholerae lipopolysaccharide (LPS), the antigen that mediates serogroup-specific responses, are associated with protection against disease. Despite this, responses against V. cholerae O-specific polysaccharide (OSP), a key component of the LPS responsible for specificity, have not been characterized in children. Here, we report a comparison of polysaccharide antibody responses in children from a region in Bangladesh where cholera is endemic, including infants (6 to 23 months, n = 15), young children (24 to 59 months, n = 14), and older children (5 to 15 years, n = 23) who received two doses of a killed oral cholera vaccine 14 days apart. We found that infants and young children receiving the vaccine did not mount an IgG, IgA, or IgM antibody response to V. cholerae OSP or LPS, whereas older children showed significant responses. In comparison to the vaccinees, young children with wild-type V. cholerae O1 Ogawa infection did mount significant antibody responses against OSP and LPS. We also demonstrated that OSP responses correlated with age in vaccinees, but not in cholera patients, reflecting the ability of even young children with wild-type cholera to develop OSP responses. These differences might contribute to the lower efficacy of protection rendered by vaccination than by wild-type disease in young children and suggest that efforts to improve lipopolysaccharide-specific responses might be critical for achieving optimal cholera vaccine efficacy in this younger age group.  相似文献   
78.
79.
80.
It has been observed that operating the intra‐aortic balloon at an angle to the horizontal resulted in a reduction of the volume displaced toward the coronary arteries and compromised afterload reduction. Therefore, the aim of this work is to examine whether changing the current balloon shape, which has not been altered for 40 years, could compensate for the negative hemodynamic effects due to angulation. We tested two tapered balloons, increasing diameter (TID) and decreasing diameter (TDD), and compared the results with those obtained from a standard cylindrical balloon. The balloons were tested in vitro at 60 beats/min and a static pressure of 90 mm Hg. The balloons were operated at four angles (0°, 20°, 30°, 45°), and the pressure at three locations along the balloon (base, middle, and tip) was also measured. Flow rate upstream of the tip of the balloon was also measured to indicate the flow displaced toward the coronary circulation. The relative volume displaced toward (VUTVi) and suctioned away from (VUTVd) the simulated ascending aorta, during inflation and deflation, respectively, is reduced when a standard cylindrical balloon is operated at an angle to the horizontal. The TDD provided the greatest VUTVi and also produced the largest pulse pressure during deflation. Although the TID provided less VUTVi and VUTVd at smaller angles, it was not markedly affected by the change of angle. According to these results, different balloon shapes analyzed, with comparable volume to that of a cylindrical balloon, produced greater inflation and deflation benefits, at the horizontal and at a range of angles to the horizontal. Further investigations are required to optimize the shape of the tapered balloons to fit into the available physiological space.  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