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   2394篇
  免费   144篇
  国内免费   8篇
耳鼻咽喉   52篇
儿科学   151篇
妇产科学   18篇
基础医学   220篇
口腔科学   42篇
临床医学   127篇
内科学   582篇
皮肤病学   43篇
神经病学   92篇
特种医学   133篇
外科学   433篇
综合类   49篇
一般理论   1篇
预防医学   66篇
眼科学   128篇
药学   218篇
中国医学   10篇
肿瘤学   181篇
  2023年   21篇
  2022年   42篇
  2021年   108篇
  2020年   88篇
  2019年   89篇
  2018年   112篇
  2017年   75篇
  2016年   108篇
  2015年   98篇
  2014年   148篇
  2013年   160篇
  2012年   241篇
  2011年   230篇
  2010年   118篇
  2009年   93篇
  2008年   141篇
  2007年   146篇
  2006年   105篇
  2005年   112篇
  2004年   88篇
  2003年   82篇
  2002年   57篇
  2001年   11篇
  2000年   8篇
  1999年   13篇
  1998年   8篇
  1997年   5篇
  1996年   4篇
  1995年   3篇
  1994年   2篇
  1993年   7篇
  1992年   1篇
  1991年   2篇
  1990年   3篇
  1989年   2篇
  1988年   4篇
  1987年   1篇
  1986年   2篇
  1984年   2篇
  1983年   1篇
  1982年   2篇
  1981年   1篇
  1980年   1篇
  1975年   1篇
排序方式: 共有2546条查询结果,搜索用时 15 毫秒
111.
Primary pancreatic lymphoma is a rare disease. It comprises less than 0.5 % of pancreatic neoplasm and 0.1% of malignant lymphoma. It should be differentiated from pancreatic adenocarcinoma because management differs. At computed tomography, 2 types of morphology of primary pancreatic lymphoma have been described- a localized well-circumscribed tumoral form and another diffuse enlargement infiltrating or replacing most of the pancreatic gland. Here, we are presenting computed tomography (CT) imaging features of a case of primary pancreatic lymphoma in a 27 year old female who presented with a complaint of abdominal pain radiating to the back for 3 months and yellowish discoloration of sclera and skin for the last 15 days. In contrast-enhanced computed tomography an exophytic homogenously hypoenhancing mass arising from head and neck region of pancreas was seen. Involvement of common bile duct (CBD) and duodenum was there. The main pancreatic duct was not dilated. Common hepatic artery was encased by mass without arterial luminal narrowing or distortion. Diagnosis of primary pancreatic lymphoma was suggested on basis of imaging findings and further confirmed with fine-needle aspiration cytology.  相似文献   
112.
Recurrent loss-of-function mutations of spliceosome gene, ZRSR2, occur in myelodysplastic syndromes (MDS). Mutation/loss of ZRSR2 in human myeloid cells primarily causes impaired splicing of the U12-type introns. In order to further investigate the role of this splice factor in RNA splicing and hematopoietic development, we generated mice lacking ZRSR2. Unexpectedly, Zrsr2-deficient mice developed normal hematopoiesis with no abnormalities in myeloid differentiation evident in either young or ≥1-year old knockout mice. Repopulation ability of Zrsr2-deficient hematopoietic stem cells was also unaffected in both competitive and non-competitive reconstitution assays. Myeloid progenitors lacking ZRSR2 exhibited mis-splicing of U12-type introns, however, this phenotype was moderate compared to the ZRSR2-deficient human cells. Our investigations revealed that a closely related homolog, Zrsr1, expressed in the murine hematopoietic cells, but not in human cells contributes to splicing of U12-type introns. Depletion of Zrsr1 in Zrsr2 KO myeloid cells exacerbated retention of the U12-type introns, thus highlighting a collective role of ZRSR1 and ZRSR2 in murine U12-spliceosome. We also demonstrate that aberrant retention of U12-type introns of MAPK9 and MAPK14 leads to their reduced protein expression. Overall, our findings highlight that both ZRSR1 and ZRSR2 are functional components of the murine U12-spliceosome, and depletion of both proteins is required to accurately model ZRSR2-mutant MDS in mice.  相似文献   
113.
BackgroundWith ever-increasing demand for total knee arthroplasty (TKA), most healthcare systems around the world are concerned about its socioeconomic burden. Most centers have universally adopted well-defined clinical care pathways to minimize adverse outcomes, maximize volume, and limit costs. However, there are no prospective comparative trials reporting benefits of these risk mitigation (RM) strategies.MethodsThis is a prospective cohort study comparing post-TKA 90-day complications between patients undergoing RM before surgery and those following a standard protocol (SP). In the RM group, we used a 20-point checklist to screen for modifiable risk factors and evaluate the need for optimizing non-modifiable comorbidities. Only when optimization goals were achieved, patients were offered TKA.ResultsTKA was performed in 811 patients in the SP group and in 829 in the RM group, 40% of which were simultaneous bilateral TKA. In both groups, hypertension was the most prevalent comorbidity (48%), followed by diabetes (20%). A total of 43 (5.3%) procedure-related complications were seen over the 90-day postoperative period in the SP group, which was significantly greater than 26 (3.1%) seen in the RM group (p = 0.039). The commonest complication was pulmonary thromboembolic, 6 in each group. Blood transfusion rate was higher in the SP group (6%) than in the RM group (< 1%).ConclusionsScreening and RM can reduce 90-day complications in patients undergoing TKA.  相似文献   
114.
115.
Journal of Neuro-Oncology - To report clinical outcomes of salvage re-irradiation (re-RT) in recurrent/progressive ependymoma. Medical records of patients treated with curative-intent re-RT as...  相似文献   
116.
AIM: To study the safety and efficacy of pegylated interferon alfa-2b, indigenously developed in India, plus ribavirin in treatment of hepatitis C virus(HCV). METHODS: One-hundred HCV patients were enrolled in an open-label, multicenter trial. Patients were treated with pegylated interferon alfa-2b 1.5 μg/kg per week subcutaneously plus oral ribavirin 800 mg/d for patients with genotypes 2 and 3 for 24 wk. The same dose of peginterferon plus weight-based ribavirin(800 mg/d for ≤ 65 kg; 1000 mg/d for 65-85 kg; 1200 mg/d for 85-105 kg; 1400 mg/d for 105 kg body weight) was administered for 48 wk for patients with genotypes 1 and 4. Serological and biochemical responses of patients were assessed.RESULTS: Eighty-two patients(35 in genotypes 1 and 4 and 47 in 2 and 3), completed the study. In genotype 1, 25.9% of patients achieved rapid virologic response(RVR): while the figures were 74.1% for early virologic response(EVR) and 44.4% for sustained virologic response(SVR). For genotypes 2 and 3, all patients bar one belonged to genotype 3, and of those, 71.4%, 87.5%, and 64.3% achieved RVR, EVR, and SVR, respectively. In genotype 4, 58.8%, 88.2%, and 52.9% of patients achieved RVR, EVR, and SVR, respectively. The majority of patients attained normal levels of alanine aminotransferase by 4-12 wk of therapy. Most patients showed a good tolerance for the treatment, although mild-to-moderate adverse events were exhibited; only two patients discontinued the study medication due to serious adverse events(SAEs). Eleven SAEs were observed in nine patients; however, only four SAEs were related to study medication.CONCLUSION: Peginterferon alfa-2b, which was developed in India, in combination with ribavirin, is a safe and effective drug in the treatment of HCV.  相似文献   
117.
118.
Pancreatic fistula is a major cause of morbidity and mortality after pancreaticoduodenectomy. External drainage of pancreaticojejunostomy anastomosis with a stent is used to reduce the rate of pancreatic fistula. This study compares the rates of pancreatic fistula between external stent drainage versus no-stent drainage for pancreaticojejunal anastomosis following pancreaticoduodenectomy. A total of 53 patients undergoing pancreaticoduodenectomy for various benign and malignant pathologies were included in the study. An external stent was inserted across the anastomosis to drain the pancreatic duct in 26 patients and 27 patients received no stent. The primary end point was pancreatic fistula. All surgeries were done by a single surgeon with expertise in hepatobiliary pancreatic surgery at a single institute. The two groups were comparable in demographic data, underlying pathologies, presenting complaints, presence of comorbid illnesses and proportion of patients with preoperative biliary drainage, pancreatic consistency and duct diameter. The pancreatic fistula rates were similar in both the groups (11.5 vs. 14.8?%, P?=?0.725). The morbidity and surgical re-exploration rate were statistically not significant between the two groups (65.4 vs. 51.9?%, P?=?0.318 and 11.5 vs. 7.4?%, P?=?0.60). Postoperative stay was also similar with a mean of 14?days in both the groups (P?=?0.66). The mortality rate was statistically not significant in the two groups (3.8 vs. 7.4?%, P?=?0.575). External drainage of pancreaticojejunostomy anastomosis and the pancreatic duct with a stent does not decrease the rate of postoperative pancreatic fistula after pancreaticoduodenectomy.  相似文献   
119.

Introduction  

Gastrointestinal stromal tumors (GISTs) are the most common gastrointestinal mesenchymal tumors. The activating mutation in the KIT (c-kit; CD117) proto-oncogene with subsequent tyrosine kinase activation plays a central role in the pathogenesis of GIST. Tyrosine kinase inhibitors are an integral part of GIST therapy. Initial response to neoadjuvant imatinib can be expected in up to 70% of the patients, thus offering an opportunity to surgically treat those with locally advanced primary or recurrent GIST. This favorable response to imatinib, however, is plagued with development of secondary resistance during the course of therapy.  相似文献   
120.
Sinha S  Singh AK  Gupta V  Singh D  Takayasu M  Yoshida J 《Neurosurgery》2003,52(2):331-8; discussion 338-9
OBJECTIVE: Tuberculous atlantoaxial dislocation is a rare disease entity. However, tuberculosis continues to be endemic in developing countries. Its earliest clinical presentation may be nonspecific, and delay in diagnosis may lead to irreversible neurological deficit. The management of tuberculous atlantoaxial dislocation includes ventral cervicomedullary decompression, occipitocervical arthrodesis, and administration of antituberculous medications. METHODS: Eighteen patients with tuberculous atlantoaxial dislocation who presented with neck pain and/or occipital headache, restriction of neck movement, difficulty swallowing, and signs of myelopathy were studied. Four patients had evidence of associated pulmonary tuberculosis. Plain x-rays of the cervical spine, computed tomographic scans, and magnetic resonance images were obtained in all patients for diagnosis and to assess the degree of dislocation and cervicomedullary compression. Simultaneous anterior neural decompression, via a transcervical retropharyngeal approach, and posterior arthrodesis were performed on all patients while they remained under anesthesia. Antituberculous chemotherapy was continued for 18 months. RESULTS: Histopathological analysis of excised tissue was consistent with tuberculosis in all patients. However, Ziehl-Neelsen staining for acid-fast bacilli was positive in two cases, and culture for Mycobacterium tuberculosis was negative in all patients. Patients with severe myelopathy experienced marked improvement. One patient died of fulminant resistant tuberculous meningitis. CONCLUSION: The transcervical retropharyngeal approach to the craniovertebral junction provides direct access to the lesion and avoids the potential bacterial contamination of the oral and pharyngeal cavity. It also prevents the development of persistent fistulae. Posterior stabilization should be performed directly after anterior neural decompression, while the patient remains under anesthesia, to prevent neurological deterioration before subsequent posterior fixation. This technique also is helpful for early mobilization of patients. The aim of surgical treatment should be to obtain biopsy tissue and to perform radical excision of epidural granulation tissue/abscess and infected bone using microsurgical technique. Antituberculous medication must be continued for 18 months with four drug regimens, and continuous monitoring of drug toxicity should be performed throughout the course of treatment.  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