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   8648篇
  免费   386篇
  国内免费   41篇
耳鼻咽喉   64篇
儿科学   180篇
妇产科学   156篇
基础医学   1055篇
口腔科学   210篇
临床医学   594篇
内科学   2194篇
皮肤病学   223篇
神经病学   1107篇
特种医学   237篇
外科学   1184篇
综合类   35篇
预防医学   263篇
眼科学   266篇
药学   559篇
中国医学   43篇
肿瘤学   705篇
  2023年   47篇
  2022年   87篇
  2021年   163篇
  2020年   114篇
  2019年   140篇
  2018年   179篇
  2017年   128篇
  2016年   136篇
  2015年   141篇
  2014年   228篇
  2013年   258篇
  2012年   428篇
  2011年   465篇
  2010年   248篇
  2009年   220篇
  2008年   403篇
  2007年   460篇
  2006年   409篇
  2005年   457篇
  2004年   387篇
  2003年   377篇
  2002年   345篇
  2001年   229篇
  2000年   243篇
  1999年   205篇
  1998年   100篇
  1997年   84篇
  1996年   56篇
  1995年   63篇
  1994年   58篇
  1993年   54篇
  1992年   172篇
  1991年   169篇
  1990年   157篇
  1989年   169篇
  1988年   153篇
  1987年   120篇
  1986年   113篇
  1985年   133篇
  1984年   102篇
  1983年   83篇
  1979年   75篇
  1978年   45篇
  1977年   46篇
  1976年   49篇
  1974年   51篇
  1973年   57篇
  1972年   50篇
  1970年   53篇
  1969年   53篇
排序方式: 共有9075条查询结果,搜索用时 0 毫秒
101.
Three-dimensional computed tomographic angiography (CTA) is a noninvasive technique for detecting lesions after acute subarachnoid hemorrhage. We encountered extravasation on CTA, a finding that has not been reported previously. Three patients with saccular aneurysms showed extravasation on CTA performed within 3 h of the onset of hemorrhage, and all three patients died within 2 weeks. At autopsy, the site of rupture of the aneurysm was confirmed in all three cases. There were two patterns of extravasation shown by CTA, which seemed to depend on the direction of rupture. Extravasation on CTA might represent the natural progression of ruptured aneurysm and may indicate a poor prognosis.  相似文献   
102.
We report two cases of osteoblastoma, one of them an unusual case in a 32-year-old woman in whom a maxillary tumor was confidently diagnosed as an osteoblastoma at the time of primary excision and subsequently transformed into an osteosarcoma 7 years after the onset of clinical symptoms. The other patient developed osteosarcoma arising in the maxilla, which was diagnosed 3 years after the primary excision and is very suggestive of malignant transformation in osteoblastoma. We present the radiological features, including computed tomographic and magnetic resonance imaging studies, of this unusual event of transformed tumor and compare imaging features of benign and dedifferentiated counterparts of this rare tumor complex.Members of the Group for the Image Diagnosis of Craniofacial Disorders  相似文献   
103.
Annals of Nuclear Medicine - Amyloid positron emission tomography (PET) can reliably detect senile plaques and fluorinated ligands are approved for clinical use. However, the clinical impact of...  相似文献   
104.

Background

The aim of this study was to evaluate how sacrifice of the portal vein and/or hepatic vein affects remnant liver dysfunction after lateral segmentectomy or left lobe hepatectomy.

Materials and methods

Among 130 patients who underwent donor hepatectomy between March 2002 and July 2011, we enrolled lateral segment (n = 15) and left lobe donors (n = 40). We evaluated the postoperative courses and the territory of venous obstruction or congestion based on the sacrificed portal vein or hepatic vein after the donor operation: lateral segment grafts (P4a, P4b, LV4) and left lobe grafts (MV5, MV8) according to the results analyzed by MeVis Distant Service.

Results

Among lateral segment donors, the predicted sacrificed territory of portal vein and hepatic vein was 14.3% (7.3%-19.4%) in P4a + 4b: (P4a: 8.6%, P4b: 5.8%) and 2.9% (0%-8.4%) in LV4, respectively. On the other hand, in left lobe donors, the predicted congestive territory of the hepatic vein was 17.6% (2.8%-33.0%) in MV5 + 8 (7.8% in MV5 and 9.8% in MV8, respectively). The incidence of patients whose postoperative peak aspartate aminotransferase (AST) or alanine aminotransferase levels were higher than 500 IU/L was 20% in the lateral segment donors and 5% in the left lobe donors. The peak postoperative AST levels and territory of MV5 + 8 showed a significant positive correlation (R = 0.569, P < .05) among left lobe donors.

Conclusion

Territories of P4 in lateral segment donors and MV5 + 8 in left lobe donors impacted postoperative liver dysfunction. It is important to recognize the precise territory of the portal vein and the hepatic vein before the donor operation.  相似文献   
105.

Background

It is difficult to reconstruct the portal vein (PV) using a long interpositional venous graft in living donor liver transplant (LDLT) patients with portal vein thrombosis (PVT), which involves the confluence of the superior mesenteric vein (SMV) and splenic vein (SV). We successfully performed LDLT for three patients with PVT using an interpositional vascular conduit passing posterior to the pancreas without a jump graft.

Methods

Three of 130 patients who underwent LDLT in our hospital between March 2002 and June 2011 required this technique. After indentifying the location of the SMV, SV and gastrocolic trunk, we ligated and cut the posterior superior pancreaticoduodenal vein and other short branches from the PV. The PV was drawn inferiorly to the pancreas and transected at the confluence of SMV and SV. The external iliac vein or internal jugular vein was sacrificed as a graft for anastomosis to the cut end of the SMV using 6-0 polypropylene running sutures. Then the venous graft was drawn superiorly to the pancreas by passing it posterior to the pancreas parenchyma for anastomosis to the liver graft PV. The interpositional vein was placed posterior to the pancreas where the PV used to be.

Results

All three patients displayed favorable postoperative courses with the Doppler ultrasound demonstrating good portal flow perioperatively. The postoperative portogram demonstrated patency of the vascular graft.

Conclusion

This method is easy and helpful to treat portal vein thrombosis, by providing the shortest route between the PV of the donor and the SMV of the recipient.  相似文献   
106.
Renal involvement in children with influenza A virus infection   总被引:2,自引:0,他引:2  
Renal involvement in influenza A virus infection has been rarely reported. To define the clinical characteristics and the factors contributing to the development of renal involvement in influenza A virus infection, we reviewed the clinical characteristics, laboratory data, pediatric risk of mortality (PRISM) score, and the number of systemic inflammatory response syndrome (SIRS) criteria and dysfunctional organs in 45 hospitalized children with influenza A virus infection. Eleven (24.4%) patients had renal involvement. All patients with renal involvement suffered from sepsis and multiple organ dysfunction syndrome (MODS) and 5 developed acute renal failure (ARF). The incidences of dehydration, hypotension, disseminated intravascular coagulation (DIC), and rhabdomyolysis were significantly higher in patients with renal involvement. PRISM scores, the numbers of SIRS criteria and dysfunctional organs, and mortality rate were also higher in patients with renal involvement. Influenza A RNA was absent in the renal tissues of 3 patients with ARF. These results suggested that renal involvement in influenza A virus infection occurred in patients with sepsis and MODS; dehydration, hypotension, DIC, and rhabdomyolysis were factors contributing to its development; direct viral injury to the kidney did not seem to occur in influenza A virus infection.  相似文献   
107.
Background/Purpose: A simple and objective method evaluating the bowel functions of patients with anorectal anomalies is necessary. The authors applied fecoflowmetry and saline enama test for patients with anorectal anomalies to evaluate the fecodynamics and anorectal motilities in these children. Methods: The bowel functions of 16 patients who underwent repair for anorectal malformations and 5 normal controls were evaluated by saline enema test and fecoflowmetry. The correlations between the clinical scores for the bowel functions and the parameters in fecodynamic studies were investigated. Results: Seven of 16 patients exhibited periodical contractions of the rectum synchronized with relaxations of the anal canal during saline infusion as did the controls and had significantly higher clinical scores than the other patients. Two patients with severe chronic constipation lacked rectal contractions. Among the fecoflowmetric parameters, the maximum flow, average flow, and tolerable volume of saline infused into the rectum were significantly lower in the patients with low clinical scores than those of the controls. The maximal squeeze pressure and resting anal pressure were not significantly different between the patients and controls. Conclusion: Fecodynamic studies, such as fecoflowmetry and saline enema test, help in obtaining clinical indicators for the bowel functions of patients with anorectal anomalies.  相似文献   
108.
The authors report a case of a recurrent subdural hematoma (SDH) that was caused by a persistent cerebrospinal fluid (CSF) leak from an L1-2 fistula. A 34-year-old man experienced severe headaches due to SDH, and he underwent aspiration of subdural fluid four times due to recurrent collections. Further evaluation with computerized tomography (CT) myelography demonstrated extradural extravasation of contrast through an L1-2 fistula. The patient underwent an L1-2 laminectomy; a small dural defect with CSF leakage at the left nerve root sleeve was found and was repaired. Following the repair, the patient had no further recurrence of SDH. Recurrent SDH, caused by spontaneous CSF leakage through a lumbar CSF fistula, is extremely rare. In cases of recurrent SDH, radiographic workup with spinal CT myelography should be considered.  相似文献   
109.
In August 2000, a 62-year-old woman presented to another municipal hospital with macroscopic Transurethral resection of bladder tumor (TUR-Bt) was performed. The pathological hematuria. diagnosis was transitional cell carcinoma (TCC), G2 > squamous cell carcinoma (SCC). TUR-Bt repeated in July 2003 indicated recurrence. The pathological diagnosis was TCC, G2. She was referred to our hospital in August 2003 because she desired bladder preservation. After cystoscopy and random biopsy, pathological diagnosis was TCC with squamous differentiation, G1-G2, pTis. She received 7 weekly intravesical bacillus Calmette-Guerin (BCG) instillations. In April 2004, TUR-Bt was repeated and multiple recurrences were found. The pathological diagnosis was TCC with squamous differentiation, G1-G2, pTa. She received 10 weekly intravesical Pirarubicin hydrochroride instillations. In August cystoscopy and random biopsy were performed for evaluation of the intavesical instillation treatment. Pathological diagnosis was atypical squamous cells. In November, cystoscopy revealed recurrence of a bladder tumor. After admission, a small papillary tumor and multiple flat lesion biopsies demonstrated SCC without obvious invasion. The patient underwent cystectomy. There were widespread areas of full thickness squamous atypia. Most of the bladder did not show appearance of typical TCC, but the final pathological diagnosis was TCC because the case developed from TCC and could not be diagnosed as pure SCC. The diagnosis of SCC in situ of bladder is difficult, and this may contribute to its rarity.  相似文献   
110.
Seven men with a mean age of 63.9 years (59 to 67) developed dysphagia because of oesophageal compression with ossification of the anterior longitudinal ligament (OALL) and radiculomyelopathy due to associated stenosis of the cervical spine. The diagnosis of OALL was made by plain lateral radiography and classified into three types; segmental, continuous and mixed. Five patients had associated OALL in the thoracic and lumbar spine without ossification of the ligamentum flavum. All underwent removal of the OALL and six had simultaneous decompression by removal of ossification of the posterior longitudinal ligament or a bony spur. All had improvement of their dysphagia. Because symptomatic OALL may be associated with spinal stenosis, precise neurological examination is critical. A simultaneous microsurgical operation for patients with OALL and spinal stenosis gives good results without serious complications.  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