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   4364篇
  免费   293篇
  国内免费   134篇
耳鼻咽喉   31篇
儿科学   41篇
妇产科学   13篇
基础医学   127篇
口腔科学   15篇
临床医学   719篇
内科学   531篇
皮肤病学   1篇
神经病学   183篇
特种医学   1599篇
外科学   513篇
综合类   663篇
预防医学   102篇
眼科学   41篇
药学   151篇
  1篇
中国医学   13篇
肿瘤学   47篇
  2024年   7篇
  2023年   16篇
  2022年   60篇
  2021年   83篇
  2020年   78篇
  2019年   42篇
  2018年   84篇
  2017年   114篇
  2016年   153篇
  2015年   137篇
  2014年   254篇
  2013年   227篇
  2012年   279篇
  2011年   305篇
  2010年   269篇
  2009年   288篇
  2008年   312篇
  2007年   297篇
  2006年   235篇
  2005年   221篇
  2004年   181篇
  2003年   130篇
  2002年   112篇
  2001年   114篇
  2000年   109篇
  1999年   59篇
  1998年   68篇
  1997年   64篇
  1996年   44篇
  1995年   37篇
  1994年   55篇
  1993年   38篇
  1992年   30篇
  1991年   27篇
  1990年   22篇
  1989年   12篇
  1988年   17篇
  1987年   12篇
  1986年   22篇
  1985年   25篇
  1984年   25篇
  1983年   16篇
  1982年   21篇
  1981年   20篇
  1980年   18篇
  1979年   15篇
  1978年   14篇
  1977年   7篇
  1976年   10篇
  1973年   3篇
排序方式: 共有4791条查询结果,搜索用时 15 毫秒
1.
Dissection of the thoracic aorta is a life-threatening event requiring imaging studies to define the level of the tear and the intinmal flap. The “gold standard” has been angiography. This method may fail to demonstrate the dissection, however, due to overlap of the true and false lumens or a very thin flap that is imaged en face rather than tangentially. Computed tomography has a diagnostic accuracy of 95%, but can fail to image the dissection due to technical factors or a thrombosed false hunen. Magnetic resonance imaging requires a hemodynamically stable and cooperative patient. A diagnostic algorithm is proposed for diagnosis of aortic dissection based on renal function and the surgeon's imaging modality preference.  相似文献   
2.
We reviewed 12 cases of infarcts in the territory of the anterior choroidal artery (AChA) on CT and/or MRI. In each case vascular occlusion in the region was verified angiographically. Although the extent of the lesion on CT/MR images was variable, all were located on the axial images within an arcuate zone between the striatium anterolaterally and the thalamus posteromedially. The distribution of the lesions on mutiplanar MRI conformed well to the territory of the AChA demonstrated microangiographically. The variability of the extent of the infarcts may be explained by variations in the degree of occlusive changes in the AChA or the development of collateral circulation through anastomoses between the AChA and the posterior communicating and posterior cerebral arteries. The extent of the lesion appeared to be closely related to the degree of neurological deficit.  相似文献   
3.
The results obtained in 304 consecutive patients with spontaneous subarachnoid hemorrhage are described, the majority of whom (86%) were admitted while in acute condition. Only 46% of the patients in this series were in good condition at admission. The initial management was standardized for all patients, but the protocol of "delayed surgery" was applied to patients with subarachnoid hemorrhage from aneurysmal rupture. Two hundred and twenty-two patients (73%) had intracranial aneurysms. Of these, 20 (9%) were moribund and died shortly after admission; nine (4%) underwent emergency surgery due to the coexistence of a life-threatening cerebral hematoma; seven (3%) were operated upon within 3 days of admission; 78 (35%) died after rebleeding or after steady deterioration of the patient's condition due to vasospasm while awaiting surgery. Of the remaining 108 patients ready for delayed surgery, 12 (11%) (operation refused, elderly patients in poor general condition, spontaneous thrombosis of the aneurysm) were treated conservatively, and 96 (89%), who were in various clinical conditions, were actually operated on. Of these 96 patients, 79 (82%) exhibited excellent or good results, 5 (5%) were disabled, and 12 (12%) died. In the authors' experience, the overall management of intracranial aneurysms in unselected patients according to the protocol of delayed surgery results in significant loss of patients awaiting surgery, and good surgical results in the survivors.  相似文献   
4.
《Neuro-Chirurgie》2021,67(2):132-139
BackgroundMicro-arteriovenous malformations (micro-AVMs) are defined as AVMs just visible on angiography with a nidus size between 0.5 and 1 cm. Their principal manifestation is intracranial hemorrhage and their diagnosis and therapeutic management are still unclear.MethodsThe aim of our work was to show the clinical presentation, treatment and outcome of ruptured cerebral micro-AVMs in a retrospective cohort study of 19 patients and a systematic review of the literature.ResultsWe obtained a total of 20 micro-AVMs in 19 patients. The mean age was 47.3 years. Clinical presentation was acute bleeding. The mean volume of hematoma was 12.9 mm3 (0 - 60.4), with topographic distribution as follows: 64% cortical with supratentorial bleeding, 26% deep, and 10% in the posterior fossa. Among the 20 micro-AVMs of the series, 11 (55%) had endovascular management, 6 (30%) had surgical treatment and 3 (15%) had GK radiosurgery alone. All of our patients have been cured at the end of the follow up without re-permeabilization. In our series, clinical outcome showed good recovery with a mean score of 4.6 on Glasgow Outcome Scale (GOS). In the literature, 88% of patients had a GOS of 4 or 5.DiscussionIntracerebral hematoma (ICH) was the main clinical manifestation. In the case of negative initial angiographic assessment, patients must have supraselective angiographic exploration. In the case of conservative treatment of hematoma, endovascular obliteration and microsurgical exclusion seems to be reasonable therapeutic options, according to our observations.  相似文献   
5.
BackgroudRecurrent hemarthrosis following total knee arthroplasty (TKA) is a rare complication. Its pathophysiology and standard treatments have not yet been established. In this study, we report 7 cases of recurrent hemarthrosis after TKA in which failure of the initial conservative treatment was followed by angiographic embolization; in 1 of the 7 cases, arthroscopic electrocauterization was also performed after treatment failure with selective embolization.MethodsFrom January 2015 to May 2018, 7 patients visited our hospital due to recurrent hemarthrosis after TKA. Their medical records and serologic test results were reviewed to check for the presence of any bleeding disorder and history of anticoagulant use. Implant malalignment and instability were checked using X-ray. In all cases, the conservative treatment failed, so interventional angiography with selective embolization was performed, which was also followed by arthroscopic electrocauterization if the outcome was unsatisfactory.ResultsThe interval between TKA and the onset of hemarthrosis ranged from 3 to 76 months (average, 34.1 months). There was no coagulopathy and instability. All patients underwent conservative treatment at an interval of 4.3 months and the rate of relapse was 3.1 on average. On the interventional angiography, 6 cases showed vascular blush, and 1 case had pulsatile bleeding. The average duration for interventional angiography was 90.9 minutes. The average length of follow-up was 38.8 months. Embolization was successfully performed in 4 cases. In 2 of 3 failed cases, the symptoms improved without further treatment. In the remaining 1 failed case, the patient had a relapse of hemarthrosis, so an arthroscopic procedure was performed, which led to identification of the suspicious bleeding point by using preoperative angiographic findings. Electrocauterization was performed and active bleeding was stopped. All cases with recurrent hemarthrosis achieved improvement.ConclusionsInterventional angiography was used to aid in the diagnosis of recurrent hemarthrosis, and therapeutic selective embolization provided satisfactory clinical results. Even if selective embolization fails, interventional angiography may be helpful for further surgical procedures because it reveals vascular blush of a bleeding site. Therefore, interventional angiography and selective embolization should be considered to be a useful treatment for recurrent hemarthrosis after TKA.  相似文献   
6.
Summary This article is the third part of a comprehensive review on the pancreatic arterial blood supply and deals with the inferior pancreaticoducdenal a. The aim of this review is to summarise the anatomical studies, starting from Haller's reports, and to supply as far as possible, with original material, angiographic evidences for the classic anatomical notions. For this purpose, the overall research was carried out by picking out and studying 1015 selective angiographies (celiac trunk and its branches, superior mesenteric a.) taken from the angiographic archives of the Institutes of Radiology of Siena, Rome (Catholic University), and Perugia. Angiographically, the authors observed the inferior pancreaticoduodenal a., present in most instances, as arising from the superior mesenteric a., from the right accessory hepatic a., or from a common trunk with the first or the first two jejunal aa. Some variations of the course have been shown. The authors underline and discuss the discordant opinions still existing regarding the incidence of the different ways the inferior pancreaticoduodenal a. arises and the surgical importance of the variation of origin of this artery.
La vascularisation artérielle du pancréas : une mise au point. III. L'artère pancréatico-duodénale inférieure
Résumé Cet article est la troisième partie d'une étude détaillée de la vascularisation artérielle du pancréas et traite de l'a. pancréatico-duodénale inférieure. Le but de ce travail est de résumer les études anatomiques, depuis la publication de Haller, et de fournir autant qu'il est possible, avec un matériel original, les preuves angiographiques des notions anatomiques classiques. Pour cela, la recherche complète a été menée sur le choix et l'ðude de 1015 angiographies sélectives (tronc coeliaque et ses branches, a. mésentérique supérieure) tirées des archives angiographiques des instituts de radiologie de Sienne, Rome (université catholique) et Pérouse. Sur les angiographies les auteurs ont observé l'a. pancréatico-duodénale inférieure, présente dans la plupart des cas, naissant de l'a. mésentérique supérieure, de l'a. hépatique droite accessoire, ou d'un tronc commun avec la première ou les deux premières aa. jéjunales. Quelques variantes ont été montrées dans son trajet. Les auteurs soulignent et discutent les opinions encore divergentes sur la fréquence des différentes origines de l'a. pancréatico-duodénale inférieure et sur leur importance chirurgicale.
  相似文献   
7.
术前IADSA和栓塞术在鼻咽纤维血管瘤治疗中的应用   总被引:11,自引:1,他引:11  
目的:研究分析术前经动脉数字减影血管造影(IADSA)和栓塞术在鼻咽纤维血管瘤治疗中的价值。方法:分析本院21例鼻咽纤维血管瘤患者的临床分析治疗资料,1主后1年复发,再次手术治疗。22次手术中,术前行及未行IADSA和栓塞术的各11次。 术前示行和行IADSA和栓塞术的要中平均出血量和输血量。结果:术前未行和行IADSA和栓塞术的术中出量量和输血量分别为1136ml、836ml、677ml、400  相似文献   
8.
Steno-Occlusive Changes in the External Carotid System in Moyamoya Disease   总被引:1,自引:0,他引:1  
To evaluate the steno-occlusive changes in the external carotid system in moyamoya disease, cerebral angiograms of 39 moyamoya patients were retrospectively reviewed. There were 26 females and 13 males, age ranged from 4 to 62 years with a mean of 26 years. Initial symptoms were ischaemia in 27 patients, haemorrhage in 9, and none in 3. Stenosis, occlusion, and dilatation in the external carotid system were analysed angiographically. No stenosis or occlusion of the superficial temporal artery, middle meningeal artery, or occipital artery was observed in either preoperative or postoperative follow-up angiograms in any patients. Steno-occlusive changes do not occur in the external carotid system, but are confined in the internal carotid system in moyamoya disease.  相似文献   
9.
Moyamoya disease is an unusual occlusive cerebrovascular condition commonly seen in children, marked by stenosis of the internal carotid artery and circle of Willis, causing, cerebral ischemia. Moyamoya syndrome is a Moyamoya-like arteriopathy with risk factors including autoimmune disorders, thyroid disease, sickle cell disease, or Down syndrome. Trisomy 21 is a genetic disorder consistent with specific physical and behavioral characteristics, with intellectual impairment. We describe a rare case of Moyamoya syndrome manifesting as ischemic stroke in an adult with Down syndrome  相似文献   
10.
Material differentiation by dual energy CT: initial experience   总被引:9,自引:0,他引:9  
The aim of this study was to assess the feasibility of a differentiation of iodine from other materials and of different body tissues using dual energy CT. Ten patients were scanned on a SOMATOM Definition Dual Source CT (DSCT; Siemens, Forchheim, Germany) system in dual energy mode at tube voltages of 140 and 80 kVp and a ratio of 1:3 between tube currents. Weighted CT Dose Index ranged between 7 and 8 mGy, remaining markedly below reference dose values for the respective body regions. Image post-processing with three-material decomposition was applied to differentiate iodine or collagen from other tissue. The results showed that a differentiation and depiction of contrast material distribution is possible in the brain, the lung, the liver and the kidneys with or without the underlying tissue of the organ. In angiographies, bone structures can be removed from the dataset to ease the evaluation of the vessels. The differentiation of collagen makes it possible to depict tendons and ligaments. Dual energy CT offers a more specific tissue characterization in CT and can improve the assessment of vascular disease. Further studies are required to draw conclusions on the diagnostic value of the individual applications.  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