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   1533篇
  免费   75篇
  国内免费   10篇
耳鼻咽喉   20篇
儿科学   62篇
妇产科学   48篇
基础医学   101篇
口腔科学   36篇
临床医学   119篇
内科学   446篇
皮肤病学   10篇
神经病学   103篇
特种医学   44篇
外科学   401篇
综合类   17篇
预防医学   22篇
眼科学   44篇
药学   89篇
中国医学   18篇
肿瘤学   38篇
  2024年   1篇
  2023年   19篇
  2022年   17篇
  2021年   37篇
  2020年   32篇
  2019年   46篇
  2018年   50篇
  2017年   39篇
  2016年   48篇
  2015年   57篇
  2014年   58篇
  2013年   86篇
  2012年   120篇
  2011年   144篇
  2010年   72篇
  2009年   61篇
  2008年   118篇
  2007年   130篇
  2006年   107篇
  2005年   97篇
  2004年   92篇
  2003年   72篇
  2002年   60篇
  2001年   10篇
  2000年   5篇
  1999年   3篇
  1998年   5篇
  1997年   4篇
  1996年   3篇
  1995年   2篇
  1994年   1篇
  1993年   6篇
  1992年   1篇
  1991年   1篇
  1990年   1篇
  1987年   1篇
  1986年   2篇
  1980年   1篇
  1978年   1篇
  1975年   1篇
  1963年   1篇
  1947年   2篇
  1938年   1篇
  1937年   1篇
  1935年   1篇
  1934年   1篇
排序方式: 共有1618条查询结果,搜索用时 15 毫秒
1.
European Radiology - To evaluate the imaging features of hepatic epithelioid hemangioendothelioma (HEH) on multiphasic CT, MR, and FDG-PET-CT. Bi-institutional review identified 67 adults (mean...  相似文献   
2.
3.

Purpose

We studied the use of magnetic resonance imaging in the diagnosis of penile fracture.

Materials and Methods

Between 1997 and 2012, fifteen patients (age range 17-48 years, mean age 37 years) with suspected penile fracture underwent MRI examinations. Ten patients were injured during sexual intercourse, whereas four patients were traumatized by non-physiological bending of the penis during self manupilation, one patient was traumatized falling from the bed. Investigations were performed with 1.5T MR unit. With the patient in the supine position, the penis was taped against the abdominal wall and surface coil was placed on the penis. All patients were studied with axial, coronal, sagittal precontrast and postcontrast T1-weighted TSE(TR/TE:538/13 msn) and T2-weighted TSE(5290/110 msn) sequences. All patient underwent surgical exploration. The follow-up ranged from 3 months to 72 months. Clinically all patients showed normal healing process without complications. In 11 patients a shortening and thickening of tunica albuginea was observed. Three patients have post traumatic erectil disfunction.

Results

In all patient corpus cavernosum fractures were clearly depicted on a discontinuity of the low signal intensity of tunica albuginea. These findings were most evident on T1WI and also depicted on T2W sequences. Images obtained shortly after contrast medium administration showed considerable enhancement only in rupture site. Subcutaneous extratunical haematoma in all patients were also recognizable on T2 WI. MRI findings were confirmed at surgery.

Conclusions

Magnetic resonance imaging is of great value for the diagnosis of penile fracture. Furthermore this method is well suited for visualising the post-operative healing process  相似文献   
4.
Aorto-iliac occlusive (AIO) disease is one of the most common forms of arteriosclerosis obliterans (ASO).1 The gold-standard treatment of this disease is aortofemoral bypass surgery, according to the Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC II) study.1-3Surgeons have performed this procedure for many years with good long-term results. Vascular damage, bleeding, intestinal damage, ileus, myocardial infarction and renal failure are considered short-term complications. Secondary aorto-enteric fistula, sexual dysfunction, infection, graft thrombosis and anastomotic pseudo-aneurysm may be considered long-term complications.4-6 Among these complications, vascular damage, intestinal damage and aorto-enteric fistulae usually occur while introducing the graft into the femoral area.If the tunneller, which was specifically designed for aortofemoral bypass procedures, is not available for some reason, long, blunt-tipped tunnelling forceps are used instead. A nylon tape is taken through the tunnel with the tunnelling forceps after the tunnel is created. Aortic anastomosis is performed after heparinisation.Connecting the distal ends of the graft to the femoral area is performed in the conventional method by introducing the forceps into the tunnel a second time and pulling the graft through the tunnel. In an alternative method, the nylon tape that is taken through the tunnel with the tunnelling forceps is tied to the graft, which is pulled through into the femoral area. By not introducing the forceps a second time into the tunnel, complications caused by the forceps may be reduced. The results of both methods were analysed for postoperative bleeding, vascular injury and intestinal complications.  相似文献   
5.
Data on prognostic biomarkers in soft tissue sarcomas are scarce. The aim of the study was to define prognostic markers in patients with a liposarcoma, a subtype of sarcoma derived from adipose tissue. We restrospectively reviewed 85 patients with liposarcoma treated at our department from May 1994 to October 2011. Kaplan–Meier curves, uni‐, and multivariable Cox proportional hazard models and competing risk analysis were performed to evaluate the association between putative biomarkers with disease‐specific and overall survival. We observed a significant association between both alkalic phosphatase (ALP; subhazard ratio [SHR] per 1 unit increase: 1.35; 95%CI 1.10–1.65; p = 0.005) and C‐reactive protein (CRP; SHR per 1 mg/dl increase: 2,57; 95%CI 1.36–4,86; p = 0.004) with disease‐specific survival. Hemoglobin (Hb) (HR per 1 g/dl increase: 065; 95%CI 0.48–0.87; p = 0.003) was associated with overall survival. These associations prevailed after multivariable adjustment for AJCC tumor stage. This study identifies CRP and ALP as novel independent predictors of disease‐specific survival in patients with liposarcoma. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:765–770, 2015.  相似文献   
6.
Cerebrospinal fluid fistula secondary to head trauma is a potentially dangerous problem and precise localization and radical treatment is mandatory. The diagnostic technique is either computed tomography cisternography or MR cisternography. For evaluating the safety of diagnostic modalities and efficacy of treatment especially in terms of surgery, animal studies demonstrating traumatic cerebrospinal fistula model are indispensable not only for neurosurgeons but also for neuroradiologists. The authors in this paper describe a traumatic cerebrospinal fistula in an animal model using rabbits. The cerebrospinal fluid leakage was demonstrated successfully in all eight rabbits and was verified by computed tomography cisternography. The results led us to conclude that rabbit model of traumatic cerebrospinal fluid fistula is safe and has low mortality and morbidity rates. Further studies including larger number of animals should be considered in order to verify safety more accurately.  相似文献   
7.
8.
This study investigated the effects of rutin against reproductive damage caused by toxic mercury in male rats. Thirty-five Sprague Dawley rats were used. Control group was injected with saline for 7 days. The rutin-100 group received 100 mg/kg/b.w. rutin for 7 days. Mercuric chloride (HgCl2) group received 1.23 mg/kg/b.w. of HgCl2 for 7 days. Mercury chloride + rutin-50 group received 50 mg/kg/b.w. rutin and HgCl2 1.23 mg/kg/b.w. for 7 days. HgCl2 + rutin-100 group received 100 mg/kg/b.w. rutin and HgCl2 1.23 mg/kg/b.w. for 7 days. It was detected that HgCl2 treatment increased malondialdehyde (MDA) levels, tumour necrosis factor-α (TNF-α) and cyclooxygenase-2 (COX-2) expressions, necrosis and degeneration of spermatogonium, dead and abnormal sperm percentages; tubular walls thinning; and decreased antioxidant enzyme activities and sperm motility. It was determined that rutin application reduced testicular damage caused by HgCl2. In conclusion, rutin administration may treat HgCl2 toxicity in testes.  相似文献   
9.
IntroductionNew radiological tools can accurately provide preoperative three-dimensional spatial assessment of metastatic renal cell carcinoma (RCC). We aimed to determine whether the distribution, volume, shape, and fraction of RCC resected in a cytoreductive nephrectomy associates with survival.MethodsWe retrospectively reviewed 560 patients undergoing cytoreductive nephrectomy, performing a comprehensive volumetric analysis in eligible patients of all detectable primary and metastatic RCC prior to surgery. We used Cox regression analysis to determine the association between the volume, shape, fraction resected, and distribution of RCC and overall survival (OS).ResultsThere were 62 patients eligible for volumetric analysis, with similar baseline characteristics to the entire cohort, and median survivor followup was 34 months. Larger primary tumors were less spherical, but not associated with different metastatic patterns. Increased primary tumor volume and tumor size, but not the fraction of tumor resected, were associated with inferior survival. The rank of tumors based on unidimensional size did not completely correspond to the rank by primary tumor volume, however, both measurements yielded similar concordance for predicted OS. Larger tumor volume was not associated with a longer postoperative time off treatment.ConclusionsPrimary tumor volume was significant for predicting OS, while the fraction of disease resected did not appear to impact patient outcomes. Although rich in detail, our study is potentially limited by selection bias. Future temporal studies may help elucidate whether the primary tumor shape is associated with tumor growth kinetics.  相似文献   
10.
The effect of direct oral anticoagulants (DOACs) on turbidimetric measurements of plasma clot formation and susceptibility to fibrinolysis may facilitate a comparison between different classes of anticoagulants in plasma samples. We obtained 424 citrate plasma samples from 226 atrial fibrillation patients on anticoagulation and 24 samples without anticoagulation serving as controls. As comparators, we measured the international normalized ratio (INR) for phenprocoumon samples (N = 166), anti-Xa for low molecular weight heparin (LMWH) samples (N = 42), and DOAC levels with mass spectrometry (dabigatran N = 40, rivaroxaban N = 110, apixaban N = 42). Plasma clot formation and lysis were recorded continuously on a photometer after addition of an activation mix (tissue factor 2 pmol/l and tissue plasminogen activator 333 ng/ml). We used linear regression and ANCOVA for correlation analysis. Clot formation lag phase was prolonged in the presence of anticoagulants in a concentration-dependent manner for DOACs (dabigatran Spearman r = 0.74; rivaroxaban r = 0.78; apixaban r = 0.72, all p < 0.0001), INR dependent for phenprocoumon (r = 0.59, p < 0.0001), anti-Xa level dependent in LMWH samples (r = 0.90, p < 0.0001). Maximum rate of clot formation and peak clot turbidity were reduced in the presence of anticoagulants, but correlated only moderately with the comparator measures of anticoagulation. The clot lysis time was inversely correlated with DOAC concentrations in the presence of recombinant thrombomodulin. A direct ex vivo comparison between the effects of different classes of anticoagulants is possible with turbidimetric measurement of plasma clot formation and lysis. Anticoagulation inhibited clot formation in a plasma concentration manner for DOACs, INR dependent for phenprocoumon, and anti-Xa dependent for LMWH. Susceptibility to fibrinolysis increased with increasing DOAC concentrations.  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