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   2845篇
  免费   81篇
  国内免费   9篇
耳鼻咽喉   116篇
儿科学   123篇
妇产科学   91篇
基础医学   179篇
口腔科学   150篇
临床医学   186篇
内科学   460篇
皮肤病学   41篇
神经病学   287篇
特种医学   111篇
外科学   684篇
综合类   34篇
预防医学   61篇
眼科学   151篇
药学   101篇
中国医学   1篇
肿瘤学   159篇
  2023年   15篇
  2022年   36篇
  2021年   64篇
  2020年   42篇
  2019年   32篇
  2018年   55篇
  2017年   50篇
  2016年   103篇
  2015年   99篇
  2014年   119篇
  2013年   150篇
  2012年   193篇
  2011年   178篇
  2010年   102篇
  2009年   106篇
  2008年   207篇
  2007年   244篇
  2006年   238篇
  2005年   205篇
  2004年   184篇
  2003年   162篇
  2002年   114篇
  2001年   51篇
  2000年   37篇
  1999年   30篇
  1998年   28篇
  1997年   17篇
  1996年   14篇
  1995年   7篇
  1994年   15篇
  1993年   5篇
  1992年   9篇
  1991年   3篇
  1990年   4篇
  1989年   2篇
  1988年   2篇
  1987年   1篇
  1986年   2篇
  1985年   2篇
  1984年   1篇
  1982年   1篇
  1977年   1篇
  1974年   1篇
  1973年   1篇
  1970年   1篇
  1969年   1篇
  1961年   1篇
排序方式: 共有2935条查询结果,搜索用时 15 毫秒
61.

Background

The aim of this study was to evaluate the sensitivity and specificity of physical examination findings and functional tests in adult acute wrist trauma patients who presented to the emergency department (ED) and to create a reliable and practical clinical decision rule for determining the necessity of radiography in wrist trauma.

Methods

This prospective observational study was conducted in a tertiary ED. Each patient was checked for 18 physical examination findings and functional tests. Patients with suspected fracture were enrolled consecutively. Antero-posterior and lateral wrist views were performed for each patient. All radiographical studies were interpreted by an orthopedic surgeon. The prevalence, sensitivity and specificity, negative and positive predictive values of each finding were calculated. A modeling for predicting fractures was created using computer.

Results

207 patients were evaluated and 69 patients (33.3%) had fractures. The most common encounterd fracture site was distal radius (29.5%). The most sensitive examination finding was pain in dorsiflexion (95.7%) and the most specific finding was ecchymosis (97.8%). Wrist edema, deformity and pain aggravated by pronation were found to be strong predictors of fracture. The area under the receiver operating characteristic curve at internal validation for a prediction model based on these three predictors was 0.88 (95% CI: 0.83-0,93). The overall sensitivity and specificity of this model were 94% (95% CI: 85-98%) and 51% (95% CI 43-60%) respectively. According to the model created in this study, 34% of acute blunt wrist trauma patients do not require any X-ray imaging.

Conclusions

This triple modeling may be used as an effective decision rule for predicting all wrist fractures in the ED and in the disaster setting.  相似文献   
62.

Introduction

The diagnostic accuracy of the FAST exam performed by EM residents were shown to be similar to radiology residents. However, in the last 2 decades, an extended-FAST (E-FAST) protocol including thoracic examination to exclude pneumo- and hemothorax was introduced. The accuracy of emergency physicians (EPs) while performing E-FAST is a less studied area, especially in Europe. The aim of this study was to compare the diagnostic accuracy of the E-FAST exam performed by EM residents with the results of CT scan as a gold standard.

Methods

This was a prospective, observational, diagnostic accuracy study conducted at the ED of a Level 1 Trauma Center. All consecutive adult multiple trauma patients were eligible, and any patient in whom thoraco-abdominal CT was ordered were recruited. Unstable and unavailable patients were excluded. E-FAST examination was performed by EPs as the index test, and CT examinations reported by a blinded academic radiology faculty was the gold standard.

Results

A total of 140 patients were recruited from eligible 144 patients. The final study population was 132 for abdominal and 130 for thorax examinations. In this study, AUC of E-FAST was 0.71 for abdominal free fluid, 0.87 for pneumothorax and 1.00 for pleural effusion. The sensitivity was 42.9% and specificity was 98.4%. The + LR for abdominal free fluid was 26.8 and ? LR was 0.58.

Conclusion

E-FAST examination has an excellent specificity. However, the sensitivity of the test is not high enough to rule-out thoraco-abdominal injuries in trauma patients when performed by EPs.  相似文献   
63.
目的:探讨放射状角膜切开术在轻中度圆锥角膜治疗中光学和视力康复的效果。
  方法:回顾性分析应用放射状角膜切开术治疗圆锥角膜的病例22例31眼并进行了至少12 mo的随访。测量并分析术前术后裸眼视力,最佳矫正视力,自动屈光计值,角膜曲率,角膜不规则指数以及并发症。
  结果:在最后一次随访中,平均裸眼视力( logMAR)由0.86±0.34显著提升至0.30±0.29(P<0.0001),平均最佳矫正视力由0.47±0.21提升至0.17±0.23(P<0.0001)。平均角膜曲率由48.69±3.68 D 降低至44.33±3.09 D ( P<0.0001)。自动屈光计测得平均等效球镜值由-5.61±2.85D显著提升至-2.29±1.95D(P<0.0001)。在整个随访过程中,中央角膜厚度和3mm,5mm区域的角膜不规则指数均无变化。术中和术后没有观察到严重并发症。
  结论:在本组病例中,放射状角膜切开术是轻中度圆锥角膜视觉康复的有效治疗方法。  相似文献   
64.
AIM: To evaluate QT dispersion (QTD) in patients with central serous chorioretinopathy (CSC). METHODS: This clinical, comperative, case-control study included 30 patients with CSC at acute phase (Group 1) and 30 age- and sex-matched healthy subjects (Group 2, the control group). From all subjects, a 12-lead surface electrocardiography was obtained. The heart rate (HR), QT maximum (QTmax), QT minimum (QTmin), QT corrected (QTc), QTD and Tmean were manually measured and analyzed. Student’s t-test and Pearson’s method of correlation were used for statistical analysis. RESULTS: The patient and control groups were matched for age, smoking status (rate and duration) and gender. There were no significant differences with regard to these among the groups (P>0.05). The participants included 19 men (63.3%) and 11 women (36.7%) in Group 1, 20 men (66.7%) and 10 women (33.3%) in Group 2. QTmax, QTD and QTc were significantly higher than those of healthy controls (P<0.001 for QTmax, P=0.01 for QTD and P=0.001 for QTc). QTmin, Tmean and HR did not differ significantly between the study groups (P=0.28 for QTmin, P=0.56 for Tmean and P>0.05 for HR). No significant correlation was found between duration of the disorder and QTD values (r=0.13, P>0.05). CONCLUSION: These findings suggest that CSC may be associated with an increase in QTD and that the patients might be at risk for ventricular arrhythmia.  相似文献   
65.

AIM

To investigate the association of serum glucocorticoid kinase gene-1 (SGK-1) DNA variants with chronic central serous chorioretinopathy (CSC).

METHODS

We enrolled 32 eyes of 32 patients who were diagnosed with chronic CSC and composed 32 normal eyes as a control group. Peripheral blood was used for DNA extraction and polymerase chain reaction (PCR) amplification. SGK1 gene was sequenced by using BigDye® Terminator v3.1 cycle sequencing KIT (Applied Biosystems, Foster City, CA, USA). The SGK1 gene and its variants were investigated in CSC patient group and control group.

RESULTS

We identified a new polymorphism M32V in two person in the patient group (Minor allele frequency (MAF)=0.009) on the region of 1-60 amino acids. The rs1057293 was located in the encoder region of the SGK 1 gene but not associated with CSC (P=0.68). An intrinsic rs1743966 is also not associated (P=0.28).

CONCLUSIONS

The new polymorphism M32V is located on the region of 1-60 amino acids which is necessary for localization to the mitochondria in CSC patient. This mutation is probably important for the energy metabolism and plays an important role in the cellular response to hyperosmotic stress and other stress stimuli. Both rs1057293 and rs1743966 are not associated with CSC.  相似文献   
66.
We examined the association between serum trace elements and clinical findings such as number of sensitive tender points, severity of fatigue and functional status in patients with fibromyalgia (FM). Thirty-two patients diagnosed as having FM according to the ACR 1990 criteria and 32 normal healthy controls (NHC) were included in this study. The demographic data, disease duration, number of tender points and accompanying symptoms (fatigue, sleep disorders, headache, paresthesia, irritable bowel syndrome, sicca symptoms, Raynaud's phenomena) of the patients were noted. Visual analog scale (10 cm) was implemented to estimate daily severity of pain and fatigue. Fibromyalgia impact questionnaire was used for functional assessment. Serum selenium (mug/dL) and serum zinc (mug/dL) levels were measured by atomic absorption spectrometer. Serum magnesium (mmol/L) level was measured by the original kits of Abbott Aeroset auto-analyzer. The mean age of patients in FM group and NHC were calculated as 42.9 (SD = 7.7) years and 41.3 (SD = 9.7) years, respectively. Serum levels of zinc (P = 0.001) and magnesium (P = 0.002) were significantly decreased by FM groups, whereas there was no considerable difference with selenium levels of both groups (P > 0.05). Association between serum zinc level and number of tender points (P = 0.008) and that between fatigue and magnesium level (P = 0.003) was found as meaningful. According to the results of this study, it was asserted that serum magnesium and zinc levels may play an important role in the pathophysiology of FM.  相似文献   
67.
ObjectiveThe purpose of this study was to compare the effects of a 6-week program of pelvic floor muscle training (PFMT) plus connective tissue massage (CTM) to PFMT alone in women with overactive bladder (OAB) symptoms on those symptoms, pelvic floor muscle strength, and quality of life.MethodsThirty-four participants were randomly divided into PFMT+CTM (n = 17) and PFMT (n = 17) groups. PFMT was applied every day and CTM was applied 3 days a week for 6 weeks. Before treatment, at week 3, and after treatment (week 6), we assessed pelvic floor muscle strength (with a perineometer), bladder symptoms (with a urine diary), OAB symptom severity (with the 8-item Overactive Bladder Questionnaire [OAB-V8]), urgency (with the Patient Perception of Intensity of Urgency Scale [PPIUS]), and quality of life (with King's Health Questionnaire [KHQ]). The Mann–Whitney U test, χ2 test, Friedman test, and Dunn multiple comparison test were used for analysis.ResultsIn both groups, pelvic floor muscle strength increased, whereas OAB symptoms and PPIUS and KHQ scores decreased after treatment (P < .05). Although the OAB-V8, PPIUS, and KHQ scores decreased at week 3, frequency, OAB-V8, and PPIUS scores, in addition to some parameters of the KHQ, decreased after treatment in the PFMT+CTM group compared to the PFMT group (P < .05).ConclusionCompared to PFMT alone, PFMT+CTM achieved superior outcomes in reducing OAB symptoms in the early and late periods.  相似文献   
68.
69.
Cervical artery dissection (CeAD) is a frequent cause of stroke among young patients. It is unclear how many CeADs occur asymptomatically or cause subtle and unspecific clinical symptoms. We hypothesize that CeAD remains often unrecognized. Accordingly, the incidence of CeAD might be higher and the stroke risk lower than generally assumed. Lack of CeAD-indicating clinical symptoms is regarded as the main cause of missed diagnoses. We further hypothesize that underrepresentation of asymptomatic and oligosymptomatic patients in CeAD studies may have biased the association between ischemia and local symptoms in CeAD patients as well as the associations of CeAD with risk factors or co-morbidities. We finally hypothesize that symptomatic CeAD may be preceded by an initial asymptomatic phase. According to this final hypothesis, the time of onset of CeAD should be considered uncertain. The issue of unrecognized CeAD is relevant, as it may affect the associations between CeAD and putative risk factors. Furthermore, the existence of clinically silent CeADs may explain why recurrent and familial CeAD have been rarely observed.  相似文献   
70.

Purpose

To review the 64-slice CTA (computed tomography angiography) appearance of anatomical variations in branching pattern of the arcus aorta, and to determine their prevalence in 1001 cases.

Materials and methods

1001 cases that underwent carotid CTA (performed by a 64-slice scanner) were included in the study.

Results

Seven types of aortic arch were found. In 853 cases (853/1001, 85.2 %) classical branching pattern of arcus aorta (three branches; TB, LCC, LS) was observed. Variations were present in 147 cases (147/1001, 14.7 %). One case (1/1001, 0.1 %) had right aortic arch. The most frequent variation was origination of LCC from TB (arch with 2 branches, TB with LCC and LS) which was observed in 78 cases (78/1001, 7.8 %). Origination of LV directly from the aortic arch (four branches; TB, LCC, LV, LS or TB, LCC, LS, LV) was observed in 51 cases (51/1001, 5.1 %). In two cases (2/1001, 0.2 %) truncus bicaroticus (3 branches; RS, common trunk for carotids, LS) was present. In seven cases (7/1001, 0.7 %) aortic arch had four branches in the order of RCC, RS, LCC and LS. In one case (1/1001, 0.1 %) left truncus brachiocephalicus (three branches; RS, RCC, LTB) was present. Seven cases (7/1001, 0.7 %) had aberrant RS (RCC, LCC, LS, RS).

Conclusion

Variations in branching pattern of arcus aorta are not rare and being aware of them before surgical and interventional procedures of this region is important. CTA can depict the anatomical features of the aortic arch and is valuable as a road map.  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