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   2945篇
  免费   169篇
  国内免费   16篇
耳鼻咽喉   35篇
儿科学   228篇
妇产科学   159篇
基础医学   153篇
口腔科学   38篇
临床医学   242篇
内科学   457篇
皮肤病学   56篇
神经病学   374篇
特种医学   114篇
外科学   753篇
综合类   163篇
预防医学   46篇
眼科学   106篇
药学   144篇
  1篇
中国医学   11篇
肿瘤学   50篇
  2023年   47篇
  2022年   48篇
  2021年   69篇
  2020年   101篇
  2019年   96篇
  2018年   95篇
  2017年   75篇
  2016年   77篇
  2015年   69篇
  2014年   106篇
  2013年   189篇
  2012年   101篇
  2011年   96篇
  2010年   106篇
  2009年   116篇
  2008年   137篇
  2007年   134篇
  2006年   153篇
  2005年   115篇
  2004年   82篇
  2003年   96篇
  2002年   76篇
  2001年   67篇
  2000年   85篇
  1999年   70篇
  1998年   61篇
  1997年   40篇
  1996年   61篇
  1995年   64篇
  1994年   56篇
  1993年   57篇
  1992年   48篇
  1991年   38篇
  1990年   34篇
  1989年   38篇
  1988年   27篇
  1987年   43篇
  1986年   30篇
  1985年   26篇
  1984年   17篇
  1983年   10篇
  1982年   23篇
  1981年   14篇
  1980年   10篇
  1979年   8篇
  1978年   7篇
  1976年   2篇
  1975年   2篇
  1974年   2篇
  1973年   2篇
排序方式: 共有3130条查询结果,搜索用时 15 毫秒
1.
Pseudoaneurysms in the external carotid artery system are rare, mostly reported in the superficial temporal and facial arteries. The bilateral sagittal split osteotomy has a low incidence of complications requiring emergency interventions. We report the case of a patient with acute bleeding from a pseudoaneurysm of the inferior alveolar artery diagnosed by angiography and treated successfully by super-selective embolization.  相似文献   
2.
BackgroundCarbetocin has been found to be superior to oxytocin in terms of need for additional uterotonics and prevention of postpartum haemorrhage at caesarean delivery. However, this is based on combined data from labouring and non-labouring parturients and it remains unclear how effective carbetocin is in the purely elective setting. The aim of this review was to compare carbetocin to oxytocin in elective caesarean delivery.MethodsMedline, Embase, CINAHL, Web of Science, and the Cochrane databases were searched for randomised controlled trials in any language. The primary outcome was need for additional uterotonics. Secondary outcomes were mean blood loss, need for blood transfusion and incidence of postpartum haemorrhage >1000 mL.ResultsNine studies with a total of 1962 patients were included. Trial sequential analysis confirmed that the information size (n=1692) had surpassed that required (n=1166) in order to demonstrate a statistically significant reduction in the use of additional uterotonics. Need for additional uterotonics was reduced by 53% with carbetocin compared to oxytocin (OR 0.47, 95% CI 0.34 to 0.64; P <0.001, I2=63.5). The number needed-to-treat was 11. The risk of bias, data heterogeneity and inconsistency in reporting bleeding outcomes made it difficult to reach definite conclusions about prevention of PPH.ConclusionsCarbetocin is associated with a reduced need for additional uterotonics when compared with oxytocin at elective caesarean delivery. Standardisation of bleeding-related outcomes in studies is necessary to facilitate synthesis of data in future analyses.  相似文献   
3.
Von Willebrand Disease is a common cause of excessive bruising and bleeding in children. This short article gives advice on diagnosis and management for paediatricians. Given its prevalence and presenting symptoms, VWD should always be considered in the assessment of children suspected of non-accidental injury. Its diagnosis can be challenging, not only because of the various subtypes of the disorder but because of the considerable overlap between VWD and normal individuals. Laboratory diagnosis requires a range of quantitative and qualitative tests of the VWF protein, with targeted gene analysis increasingly used to confirm the diagnosis of type 2 and type 3 VWD. Bleeding Assessment Tools may be helpful in directed laboratory testing but are often less so in young children who have had limited haemostatic challenges. Treatment for VWD includes the use of antifibrinolytic drugs, vasopressin or VWF-containing clotting factor concentrates. Treatment is often on-demand for individual bleeding episodes but there are specific indications for the use of prophylactic treatment in children.  相似文献   
4.
The case concerns a 20 year-old woman with a sudden visual loss in her left eye. In the fundus examination, a focal pre-retinal haemorrhage was observed in the superior temporal vascular branch with accompanying vitreous haemorrhage. There was a favourable spontaneous outcome. Eighteen months later, she presented with a new visual loss in the same eye, showing a sub-hyaloid pre-macular haemorrhage that was satisfactorily drained by hyaloidotomy using a Nd-YAG laser. The patient had also presented with an upper digestive tract haemorrhage and menorrhagia. A haemostasis study was performed that showed a coagulation factor VII deficiency. This is a very uncommon disorder that has not been previously described in association with the appearance of pre-retinal haemorrhages.  相似文献   
5.
IntroductionMucosal leishmaniosis (ML) is a severe clinical form of leishmaniosis. Complex factors related to the parasite and the host are attributed to the development of mucosal lesions. Leishmania RNA virus 1 (LRV1) can disrupt immune response, and may be the main determinant of severity of the disease; it should be investigated.ObjectiveTo study the existence of clinical differences between patients with ML with endosymbiosis by LRV1 and. those without it.MethodsA cross-sectional cohort study with clinical evaluation, polymerase chain reaction (PCR) detection of Leishmania, species classification, and search of LRV1 was performed. Only patients with confirmed diagnosis of ML by positive PCR and with nasal mucosa injuries were included in this analysis.ResultsOut of 37 patients, 30 (81.1%) were diagnosed with Leishmania braziliensis, five (13.5%) with Leishmania guyanensis, and two (5.4%) with mixed infection of L. braziliensis and L. guyanensis. LVR1 virus was present in 26 (70.3%) of the cases.ConclusionCorrelation between clinical phenotype and presence of LRV1 was not observed, although the frequency of the virus is two-fold higher in mucosal lesions than that found in the literature on skin lesions in the same geographical area.  相似文献   
6.
7.
目的探讨施他宁(生长抑素)联合奥美拉唑治疗肝硬化合并上消化道大出血的疗效。方法将确诊的83例患者随机分为三组。治疗组采用施他宁联合奥美拉唑的治疗方案,对照1组采用奥曲肽联合奥美拉唑的方案,对照2组采用垂体后叶素联合奥美拉唑的方案,观察时间为72 h。结果治疗组、对照1组、对照2组的止血有效率分别为93.3%、68.0%、57.1%,治疗组的止血有效率明显高于两个对照组(P<0.05);治疗组、对照1组、对照2组的有效止血时间分别为(29.71±6.35)h,(38.24±7.04)h,(40.88±9.98)h,治疗组的有效止血时间明显短于两个对照组(P<0.01)。结论施他宁联合奥美拉唑治疗肝硬化合并上消化道大出血疗效满意。  相似文献   
8.
This is a retrospective review of the results at our institution of using multi-detector CT angiography (CTA) to localise lower gastrointestinal (GI) bleeding. We hypothesised that in our patient population: (i) CTA was unlikely to demonstrate bleeding in patients who were haemodynamically stable; (ii) in haemodynamically unstable patients in whom CTA was undertaken, the results could be used to select patients who would benefit from catheter angiography; and (iii) in haemodynamically unstable patients in whom CTA was undertaken, a subgroup of patients could be identified who would benefit from primary surgical treatment, avoiding invasive angiography completely. A retrospective review was conducted of the clinical records of all patients undergoing CTA for lower GI haemorrhage at our institution between 1 January 2005 and 30 June 2007. Out of the 20 patients examined, 10 had positive CTAs demonstrating the bleeding site. Nine were haemodynamically unstable at the time of the study. Four patients with positive CT angiograms were able to be treated directly with surgery and avoided invasive angiography. Ten patients had negative CTAs. Four of these were haemodynamically unstable, six haemodynamically stable. Only one required intervention to secure haemostasis, the rest stopped spontaneously. No haemodynamically stable patient who had a negative CTA required intervention. CTA is a useful non-invasive technique for localising the site of lower GI bleeding. In our patient population, in the absence of haemodynamic instability, the diagnostic yield of CTA was low and bleeding was likely to stop spontaneously. In haemodynamically unstable patients, a positive CTA allowed patients to be triaged to surgery or angiography, whereas there was a strong association between a negative CTA and spontaneous cessation of bleeding.  相似文献   
9.
We describe a 15-y-old girl with Fechtner-like syndrome, who is the first Chinese reported to have this rare syndrome. She presented with left homonymous hemianopia and neuroimaging revealed haemorrhage in both parietal and occipital lobes. Peripheral blood smear showed macrothrombocytopenia and intracytoplasmic inclusion bodies inside leucocytes. Thrombocytopenia and proteinuria responded to intravenous immunoglobulin and pulsed methylprednisolone. This case illustrates that life-threatening haemorrhage can occur in patients with Fechtner syndrome. Although there was no effective treatment reported in the literature, high dose steroid and immunoglobulin seemed to be useful in our patient. Our patient also had nephritic-nephrotic syndrome with renal insufficiency, which is unusual in adolescent female patients.  相似文献   
10.
A 15-year-old girl presented de novo in diabetic ketoacidosis having been comatose for 24 h (day 1). A CT scan and lumbar puncture performed on admission were normal and her conscious level slowly improved over several days. On day 7 she had central neurological signs of bilateral knee clonus and an extensor plantar response. In addition, she had developed lower motor neurological signs of an ulnar nerve palsy of the left forearm, and ulnar, median, and radial nerve palsies of the right forearm. Magnetic resonance imaging (MRI), performed on day 12, showed multiple small cerebral haematomata with appearances at least several days of age. The scattered lesions were localized particularly to the parieto-occipital region, with sparing of the basal ganglia and without cerebral oedema, a novel feature not previously described in juvenile ketoacidosis. Four months later there was minimal residual disability of her right arm. The clinical findings together with the MRI images suggested that the peripheral nerve and central lesions were temporally related, suggesting a common aetiology. However, it is likely that MRI showed cerebral lesions which may have been missed by the conventional CT scanning performed initially.  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