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   933篇
  免费   79篇
  国内免费   4篇
耳鼻咽喉   7篇
儿科学   20篇
妇产科学   18篇
基础医学   104篇
口腔科学   135篇
临床医学   161篇
内科学   170篇
皮肤病学   23篇
神经病学   83篇
特种医学   20篇
外科学   41篇
综合类   2篇
预防医学   90篇
眼科学   10篇
药学   84篇
中国医学   1篇
肿瘤学   47篇
  2023年   8篇
  2022年   17篇
  2021年   24篇
  2020年   21篇
  2019年   28篇
  2018年   27篇
  2017年   23篇
  2016年   38篇
  2015年   29篇
  2014年   40篇
  2013年   53篇
  2012年   80篇
  2011年   86篇
  2010年   44篇
  2009年   45篇
  2008年   66篇
  2007年   66篇
  2006年   37篇
  2005年   34篇
  2004年   35篇
  2003年   36篇
  2002年   46篇
  2001年   11篇
  2000年   15篇
  1999年   7篇
  1998年   7篇
  1997年   7篇
  1996年   10篇
  1995年   9篇
  1994年   4篇
  1993年   4篇
  1992年   5篇
  1991年   9篇
  1990年   6篇
  1989年   5篇
  1988年   3篇
  1987年   2篇
  1986年   2篇
  1985年   2篇
  1984年   1篇
  1983年   5篇
  1982年   1篇
  1981年   2篇
  1980年   7篇
  1979年   1篇
  1978年   2篇
  1977年   1篇
  1976年   4篇
  1975年   1篇
排序方式: 共有1016条查询结果,搜索用时 15 毫秒
31.
Objective: The present study reports on the application of a Swedish translation of the audiologist occupational stress questionnaire (AOSQ) on audiologists working in Sweden. The relations between AOSQ scores and perceived effort, perceived rewards, coping strategies at work, demographic variables such as salary, education length, practise length, and practice type were tested. Design: A cross-sectional e-mail survey using the AOSQ, effort-reward imbalance questionnaire, and demographic questions. Study sample: Four-hundred and four Swedish licensed audiologists working with clients. Results: The Swedish AOSQ translation demonstrated high inter-item correlations and high internal consistency. Several stress factors were identified: time spent at work, accountability, leadership at the workplace, paperwork and practice demands, equipment and clinical protocols, own health concerns, and job control. The outcome on the complete AOSQ questionnaire was related to perceived effort, perceived rewards, coping strategies at work, and age. Conclusions: The Swedish AOSQ translation seems to provide a valid measure of occupational stress among audiologists.  相似文献   
32.
The purpose of the study was to assess the reliability of the specific multiple sclerosis quality of life (MSQOL-54) instrument, which contains 54 items measuring quality of life, among Finnish multiple sclerosis (MS) patients. Nursing professionals evaluated the clarity and comprehensibility of the translated instrument, after which it was pilot-tested. The data were collected through a questionnaire survey in the spring 2004. Persons diagnosed with MS in 1999-2001 filled in the questionnaire (n = 100). The response percentage was 81%. The structural validity of the MSQOL-54 instrument was evaluated with factor analysis and the generic 15D quality of life instrument. The internal consistency of the instrument was measured with Cronbach's alpha, correlations and item analysis. According to the results, the structural validity of MSQOL-54 was good, and factor analysis yielded a clear-cut factorial model. More than half of the correlations between the comparable items of the 15D and MSQOL-54 instruments were moderate or better. The internal consistency of MSQOL-54 can hence be considered quite good: Cronbach's alpha coefficients calculated for the factors and their items ranged within 0.33-0.89. The alpha coefficient calculated for the whole instrument was 0.84. The internal consistency of MSQOL-54 was further confirmed by the results of an item analysis, which showed the correlation coefficients between the items of the different dimensions to be good (0.31-0.81). On the basis of the test results, the MSQOL-54 instrument is fairly reliable and suitable for assessing the health-related quality of life of MS patients. The reliability of MSQOL-54 should be evaluated further by a longitudinal study design in the future.  相似文献   
33.
34.
OBJECTIVE: Our aim was to evaluate the association between dental attendance and dental fear while considering the simultaneous effects of perceived oral health and treatment need, satisfaction with oral health services, age, gender, marital status, and attained level of education. MATERIAL AND METHODS: The two-stage stratified cluster sample (n=8028) represented Finnish adults aged 30 years and older. The response rate to this nationwide sample was 88%. Dental fear was measured with the question: "How afraid are you of visiting a dentist?" Multiple logistic regression analyses were used to determine the association between dental fear and dental attendance, including the following independent variables: perceived oral health, perceived treatment need, satisfaction with oral health services, age, gender, marital status, and attained level of education. RESULTS: Among all ages, except 30 to 34-year-olds, irregular attenders were more likely to be very afraid of visiting a dentist than regular attenders were. The association was stronger the older the age group. Only age modified the association between dental fear and attendance. Irregular dental attendance can be attributed to high dental fear (etiologic fraction among exposed) in 41% of cases. CONCLUSION: Reducing dental fear would increase the number of regular attenders, especially among older age groups. Individuals for whom oral health services have been provided regularly since childhood seem to continue to use these services regularly despite high dental fear.  相似文献   
35.
OBJECTIVE: To evaluate the psychometric properties (criterion validity, construct validity, sensitivity, and specificity) of a single-item question screening for dental anxiety in a Finnish adult population. MATERIAL AND METHODS: A total of 823 subjects, ranging in age from 18 to 87 years, answered a questionnaire comprising sections assessing the respondents' demographic profile and dental attendance patterns. A single dental anxiety question and the Modified Dental Anxiety Scale (MDAS) were included. The final response rate was 85%. RESULTS: Eight percent of the sample was highly dentally anxious using the MDAS cut-off point of 19 or above. Twelve percent of the respondents rated themselves as "very scared" on the single-item question. The percentage agreement between the single-item question and the MDAS was 93; the Kappa coefficient was 0.63. Specificity of the single question was 0.95 while sensitivity was 0.80 using the MDAS dichotomous classification. The single-item question related to age (p<0.001), gender (p<0.001), and dental attendance (p<0.001), as predicted. CONCLUSIONS: The single question has good validity, specificity, and sensitivity and may be used with confidence to assess dental fear in such situations as national health surveys or in routine dental practice where a multi-item dental anxiety questionnaire is not feasible.  相似文献   
36.
37.
38.

Objective

The long-term morphological changes induced by a single episode of alcoholic pancreatitis are not known. Our aim was to study these morphological changes in secretin-stimulated magnetic resonance cholangiopancreatography (S-MRCP) after the first episode of alcohol-associated acute pancreatitis and to evaluate the risk factors and possible protective factors potentially associated with later chronic findings. We have previously reported 2-year follow-up results in pancreatic morphology. This study extends the follow-up to 9 years.

Patients and Methods

In this prospective follow-up study, S-MRCP imaging was performed for 44 (41 M, 3 F; mean age, 46 (25–68)?years) patients after their first episode of alcohol-associated pancreatitis. Pancreatic morphology was evaluated at 3 months and at 2, 7, and 9 years after hospitalization. Recurrent attacks of pancreatitis were studied and pancreatic function was monitored by laboratory tests. Patients’ alcohol consumption was evaluated with questionnaires, laboratory markers, and self-estimated alcohol consumption via interview. Smoking and body mass index were annually recorded.

Results

At 3 months, 32 % of the patients had normal findings in S-MRCP, 52 % had acute, and 16 % had chronic changes. At 7 years, S-MRCP was performed on 36 patients with normal findings in 53 %, the rest (47 %) having chronic findings. Pancreatic cyst was present in 36 %, parenchymal changes in 28 %, and atrophy in 28 % of the cases. There were no new changes in the pancreas in the attending patients between 7 and 9 years (18 patients). Of the patients with only acute findings at 3 months, 60 % resolved to normal in 7 years, but the rest (40 %) showed chronic changes later on. The initial attack was mild in 65 %, moderate in 25 %, and severe in 10 % of the patients. Patients with mild first attack had fewer chronic changes at 7 years compared to patients with moderate or moderate and severe together (p?=?0.03, p?=?0.01). Of the patients in the seventh year of S-MRCP, 22 % had suffered a recurrent episode of acute pancreatitis (mean, 22 (2–60)?months) and 11 % had a clinical diagnosis of chronic pancreatitis. At 7 years, 88 % of the patients with recurrences had chronic findings in S-MRCP versus 36 % with nonrecurrent pancreatitis (p?=?0.02). Six (17 %) patients abstained from alcohol throughout follow-up (mean, 8.7 (7–9.1)?years), but even one of these developed pancreatic atrophy. Out of the non-abstinent patients who did not suffer recurrences, 4/22 (18 %) had developed new findings during at follow-up S-MRCP (NS). In univariate analysis, heavy smoking showed no correlation with increased chronic changes compared to nonsmoking.

Conclusions

Morphological pancreatic changes increase with recurrent episodes of acute pancreatitis. Patients with mild first attack have fewer chronic changes in the pancreas in the long term. However, even a single episode of acute alcoholic pancreatitis may induce chronic morphological changes in long-term follow-up.  相似文献   
39.
40.
Mesoporous and large surface area zirconium oxide aggregate granules with good adsorption properties were synthesized using a simple precipitation method. Since utilization of these small and fragile particles is considered rather difficult in larger scale column operation, the product was formed into a fibrous form to improve its usability. The submicron fibers were obtained from an optimized electroblowing synthesis that resulted in elastic and uniform fibers with a tetragonal structure and high length-to-diameter ratio. In antimonate (Sb(v)) adsorption experiments, the higher calcination temperature (350 °C) of the fibers did not seem to decrease the Sb(v) adsorption capacity excessively since the high theoretical adsorption capacities were 113 mg g−1 and 58 mg g−1 for the aggregate and fibers, respectively. Both materials had fast kinetics, fibers being faster in the beginning of the reaction. Moreover, both materials offered efficient Sb(v) removal in the studied pH range from 1 to 11 by reaching over 99.9% adsorption in the optimal pH range. X-ray absorption near edge spectroscopy (XANES) revealed that Sb(v) stays as pentavalent antimony after being adsorbed by these materials and based on the isoelectric point shifts in the zeta potential measurement, adsorption occurs mainly by an inner-sphere complexation reaction. Finally, our study showed that pressure buildup in a flow-through column packed with zirconium oxide fibers was significantly lower than in a column packed with aggregates. Thus, zirconium oxide aggregates can be formed into submicron fibers with enhanced column operation properties without a too large compromise in the adsorption properties.

Zirconium oxide was formed into submicron fibers to improve the Sb(v) separation performance compared to a conventional aggregate material.  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