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   1363篇
  免费   45篇
  国内免费   3篇
耳鼻咽喉   26篇
儿科学   57篇
妇产科学   47篇
基础医学   180篇
口腔科学   46篇
临床医学   93篇
内科学   217篇
皮肤病学   12篇
神经病学   164篇
特种医学   48篇
外科学   184篇
综合类   7篇
预防医学   89篇
眼科学   31篇
药学   123篇
肿瘤学   87篇
  2023年   3篇
  2022年   4篇
  2021年   10篇
  2020年   10篇
  2019年   26篇
  2018年   17篇
  2017年   13篇
  2016年   19篇
  2015年   20篇
  2014年   30篇
  2013年   69篇
  2012年   74篇
  2011年   83篇
  2010年   50篇
  2009年   41篇
  2008年   82篇
  2007年   86篇
  2006年   100篇
  2005年   95篇
  2004年   112篇
  2003年   91篇
  2002年   104篇
  2001年   24篇
  2000年   10篇
  1999年   17篇
  1998年   23篇
  1997年   17篇
  1996年   11篇
  1995年   18篇
  1994年   12篇
  1993年   13篇
  1992年   8篇
  1991年   17篇
  1990年   12篇
  1989年   8篇
  1988年   3篇
  1987年   7篇
  1985年   7篇
  1984年   9篇
  1983年   7篇
  1982年   8篇
  1981年   6篇
  1979年   5篇
  1977年   2篇
  1976年   3篇
  1975年   3篇
  1974年   5篇
  1969年   2篇
  1967年   2篇
  1963年   3篇
排序方式: 共有1411条查询结果,搜索用时 15 毫秒
21.
22.
Both insulin resistance and inflammation may contribute to the onset of preeclampsia. They also could be interrelated. We studied the relationship between inflammatory cytokines and markers of insulin resistance. During their third trimester, 22 proteinuric preeclamptic women and 16 normotensive controls underwent intravenous glucose tolerance test (minimal model). Preeclamptic women were more insulin-resistant (P = .009), and they had higher levels of serum soluble tumor necrosis alpha receptor II (TNFalpha RII) (P = .002), triglycerides (P = .006), uric acid (P = .001), and leptin (P = .002) than did the controls. However, the study groups did not differ in serum TNFalpha, C-reactive protein (CRP), interleukin-6 (IL-6), sex hormone-binding globulin (SHBG), and high-density lipoprotein-2 (HDL(2))-cholesterol. In multiple regression analysis only SHBG (P = .01) and triglycerides (P = .0036) were associated with insulin sensitivity independently of body mass index (BMI), weight gain, HDL(2)-cholesterol, CRP, TNFalpha, and TNFalpha RII, IL-6, and leptin. We conclude that insulin resistance and the inflammatory markers studied were not associated in established preeclampsia.  相似文献   
23.
24.
OBJECTIVE: Tuberculosis (TB) in patients with rheumatoid arthritis (RA) undergoing treatment with anti-tumor necrosis factor (TNF) agents is commonly the result of reactivation of latent TB infection (LTBI); detection and treatment of LTBI is essential before treatment with anti-TNF agents. We reported previously that the tuberculin skin test (TST) is inaccurate for diagnosis of LTBI in patients with RA. Here, we compare the prevalence of LTBI in RA patients and matched controls according to positive TST and QuantiFeron-TB Gold In-Tube version (QFT) results and determine their agreement. METHODS: A cross-sectional study of 101 RA patients and 93 controls was conducted in Lima, Perú, where the prevalence of LTBI in the general population has been estimated to be 68%. Blood was drawn for QFT assay followed by TST using 2-TU of RT 23 purified protein derivative. TST was deemed positive at >or= 5 mm for RA patients and >or= 10 mm for controls. RESULTS: There were no significant differences between RA patients and controls for age, sex, bacillus Calmette-Guérin vaccination, or history of or contact with TB. 88% of patients had active RA disease and 2 (1.9%) patients had indeterminate QFT results. The number of subjects testing positive with the QuantiFeron assay was comparable between patients and controls (44.6% vs 59.1%, respectively), whereas the TST detected significantly less LTBI among RA patients (26.7%) than controls (65.6%). Thus, the rate of LTBI in RA patients represented 75% and 41% of the rate in their controls using QFT or TST, respectively (p = 0.008). Poor agreement between TST and QFT was seen in RA patients, but in controls, good agreement was observed between these tests. CONCLUSION: In a TB-endemic population, the QuantiFeron-TB Gold In-Tube assay seemed to be a more accurate test for detection of LTBI in RA patients compared with the TST, and may potentially improve the targeting of prophylactic therapy before treatment with anti-TNF agents.  相似文献   
25.
Objective: The aim of this study was to evaluate health-related quality of life (HRQoL) in adults with hearing impairment in Finland before and after hearing rehabilitation. Design: The study was prospective with hearing-aid rehabilitation as the intervention. The data was collected, using the 15D instrument, before and six months after hearing-aid rehabilitation. The data was analysed using t-tests and multiple linear regression methods. Study sample: The study sample included 949 adults with hearing impairment, and the control group included a sample of age- and gender-standardized general population. Results: The study population had significantly poorer HRQoL on most dimensions of the 15D when compared to the control group both before and after hearing-aid rehabilitation. Hearing-aid rehabilitation resulted in improved mean scores on the dimensions of hearing and in the overall 15D score that were statistically significant, although the mean improvement in the overall score was marginal. Self-reported hearing ability can better predict the change in HRQoL, as a result of a hearing aid, when compared with measured hearing sensitivity. Conclusions: The study supports the hypothesis that on average, use of a unilateral hearing aid results in improved subjective hearing and marginal improvement in HRQoL in adults with hearing impairment.  相似文献   
26.

Background

Continuity of care is an essential aspect of quality in general practice. This study is the first systematic follow-up of Finnish primary care patients’ assessments with regard to personal continuity of care.

Aim

To ascertain whether patient-reported longitudinal personal continuity of care is related to patient characteristics and their consultation experiences, and how this had changed over the study period.

Design and setting

A 15-year follow-up questionnaire survey that took place at Tampere University Hospital catchment area, Finland.

Method

The survey was conducted among patients attending health centres in the Tampere University Hospital catchment area from 1998 until 2013. From a sample of 363 464 patients, a total of 157 549 responded. The responses of patients who had visited a doctor during the survey weeks (n = 97 468) were analysed. Continuity of care was assessed by asking the question: ‘When visiting the health centre, do you usually see the same doctor?’; patients could answer ‘yes’ or ‘no’.

Results

Approximately half of the responders had met the same doctor when visiting the healthcare centre. Personal continuity of care decreased by 15 percentage points (from 66% to 51%) during the study years. The sense of continuity was linked to several patients’ experiences of the consultation. The most prominent factor contributing to the sense of continuity of care was having a doctor who was specifically appointed (odds ratio 7.28, 95% confidence interval = 6.65 to 7.96).

Conclusion

Continuity of care was proven to enhance the experienced quality of primary care. Patients felt that continuity of care was best realised when they could consult a doctor who had been specifically appointed to them. Despite efforts of the authorities, over the past 15 years patient-reported continuity of care has declined in Finland.  相似文献   
27.
Direct oral anticoagulants provide an alternative to vitamin K antagonists for the anticoagulation therapy in atrial fibrillation (AF). The availability of several treatment options with different attributes makes shared decision‐making appropriate for the choice of anticoagulation therapy. The aim of this study was to understand how physicians choose an oral anticoagulant (OAC) for patients with AF and how physicians view patients’ participation in this decision. Semi‐structured interviews with 17 Finnish physicians (eight general practitioners and nine specialists) working in the public sector were conducted. An interview guide on experience, prescribing and opinions about oral anticoagulants was developed based on previous literature. The data were thematically analysed using deductive and inductive approaches. Based on the interviews, patient's opinion was the most influential factor in decision‐making when there were no clinical factors limiting the choice between OACs. Of patient's preferences, the most important was the attitude towards co‐payments of OACs. Patients’ opinions on monitoring of treatment, dosing and antidote availability were also mentioned by the interviewees. The choice of an OAC in AF was patient‐centred as all interviewees expressed that patient's opinion affects the choice.  相似文献   
28.
AimsHypofibrinolysis displayed by elevated serum plasminogen activator inhibitor 1 (PAI-1) level has been associated with cardiovascular disease (CVD) and its risk factors such as obesity and insulin resistance. However, no studies have examined associations between PAI-1 and CVD risk factors in healthy subjects. We examined associations between serum PAI-1, ultrasound markers of atherosclerosis and CVD risk factors and whether PAI-1 improves prediction of atherosclerosis over known risk factors in a cohort of asymptomatic adults.MethodsWe analyzed PAI-1 and CVD risk factors and assessed carotid intima-media thickness (cIMT), distensibility (CDist) and the presence of a carotid atherosclerotic plaque and flow-mediated dilation (FMD) ultrasonographically for 2202 adults (993 men and 1,209 women, aged 30–45 years) participating in the ongoing longitudinal cohort study, The Cardiovascular Risk in Young Finns Study. High cIMT was defined as >90th percentile and/or carotid plaque and low CDist and low FMD as <20th percentile.ResultsIn bivariate analyses, PAI-1 correlated directly with cIMT and the risk factors: blood pressure, BMI, waist and hip circumference, alcohol use, total and LDL-cholesterol, triglycerides, glomerular filtration rate, high-sensitivity CRP and glucose (all P < 0.005). PAI-1 was higher in men and increased with age. Inverse correlation was observed with CDist, HDL-cholesterol and adiponectin in both sexes, with testosterone and sex hormone binding globulin in men and with creatinine and oral contraceptive use in women (P < 0.005). Independent direct associations were observed between PAI-1 and waist circumference, serum triglycerides, insulin, alcohol use and age and inverse with serum creatinine, HDL-cholesterol and adiponectin. PAI-1 did not improve estimation of high cIMT, low CDist and low FMD over conventional risk factors (P for difference in area under curve  0.37).ConclusionPAI-1 was independently associated with several known CVD risk factors, especially obesity markers, in both men and women. However, addition of PAI-1 to known risk factors did not improve cross-sectional prediction of high cIMT, low CDist and low FMD suggesting that PAI-1 is not a clinically important biomarker in early atherosclerosis.  相似文献   
29.

Objective

MRI-guided real-time transcranial magnetic stimulation (TMS) navigators that apply electromagnetic modeling have improved the utility of TMS. However, their accuracy and speed depends on the assumed volume conductor geometry. Spherical models found in present navigators are computationally fast but may be inaccurate in some areas. Realistically shaped boundary-element models (BEMs) could increase accuracy at a moderate computational cost, but it is unknown which model features have the largest influence on accuracy. Thus, we compared different types of spherical models and BEMs.

Methods

Globally and locally fitted spherical models and different BEMs with either one or three compartments and with different skull-to-brain conductivity ratios (1/1–1/80) were compared against a reference BEM.

Results

The one-compartment BEM at inner skull surface was almost as accurate as the reference BEM. Skull/brain conductivity ratio in the range 1/10–1/80 had only a minor influence. BEMs were superior to spherical models especially in frontal and temporal areas (up to 20 mm localization and 40% intensity improvement); in motor cortex all models provided similar results.

Conclusions

One-compartment BEMs offer a good balance between accuracy and computational cost.

Significance

Realistically shaped BEMs may increase TMS navigation accuracy in several brain areas, such as in prefrontal regions often targeted in clinical applications.  相似文献   
30.
BackgroundWhen transcranial magnetic stimulation (TMS) is delivered close to the lateral aspects of the head, large-amplitude (~10–1000 μV) biphasic electroencephalographic (EEG) deflections, peaking at around 4–10 and 8–20 ms, appear.ObjectiveTo characterize the spatiotemporal features of these artifacts, to quantify the effect of stimulus parameters on them, and thus, to study the feasibility of different measurement procedures to decrease the artifacts online. Furthermore, to show that these deflections, when measured with a sample-and-hold system, mainly result from excitation of cranial muscles.MethodsThree subjects received TMS to 16 sites over the left hemisphere. TMS-compatible EEG was recorded simultaneously. Four other subjects received TMS to M1 with different coil rotation and tilt angles and stimulation intensities. We also stimulated a conductive phantom and recorded simultaneous EEG to exclude the possibility of residual electromagnetic artifacts.ResultsThe artifacts were largest when the stimulator was placed above cranial muscles, whereas stimulation of relatively central sites far from the muscles produced muscle artifact-free data. The laterally situated EEG channels were most severely contaminated. The artifacts were significantly reduced when reducing the intensity or when tilting or rotating the coil so that coil wings moved further away from the temporal muscle, while brain responses remained visible. Stimulation of the phantom did not produce such large-amplitude biphasic artifacts.ConclusionAltering the stimulation parameters can reduce the described artifact, while brain responses can still be recorded. The early, laterally appearing, large biphasic TMS-evoked EEG deflections recorded with a sample-and-hold system are caused by cranial muscle activation.  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