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   10231篇
  免费   572篇
  国内免费   103篇
耳鼻咽喉   163篇
儿科学   139篇
妇产科学   117篇
基础医学   1585篇
口腔科学   228篇
临床医学   762篇
内科学   2034篇
皮肤病学   364篇
神经病学   627篇
特种医学   613篇
外科学   1506篇
综合类   68篇
一般理论   3篇
预防医学   392篇
眼科学   208篇
药学   878篇
中国医学   144篇
肿瘤学   1075篇
  2024年   10篇
  2023年   80篇
  2022年   236篇
  2021年   416篇
  2020年   150篇
  2019年   268篇
  2018年   304篇
  2017年   235篇
  2016年   382篇
  2015年   470篇
  2014年   552篇
  2013年   572篇
  2012年   902篇
  2011年   803篇
  2010年   502篇
  2009年   404篇
  2008年   581篇
  2007年   535篇
  2006年   480篇
  2005年   468篇
  2004年   379篇
  2003年   328篇
  2002年   255篇
  2001年   263篇
  2000年   226篇
  1999年   167篇
  1998年   95篇
  1997年   81篇
  1996年   66篇
  1995年   68篇
  1994年   55篇
  1993年   46篇
  1992年   73篇
  1991年   56篇
  1990年   46篇
  1989年   57篇
  1988年   53篇
  1987年   43篇
  1986年   33篇
  1985年   29篇
  1984年   13篇
  1983年   17篇
  1981年   13篇
  1980年   16篇
  1979年   10篇
  1978年   9篇
  1977年   6篇
  1976年   11篇
  1973年   6篇
  1968年   6篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
BACKGROUND: Tumour recurrence is common after hepatic resection of hepatocellular carcinomas (HCCs) greater than 10 cm in diameter. This study evaluated the outcome of patients with huge HCC after primary resection and treatment of recurrent lesions. METHODS: A retrospective review was undertaken of clinical data for 100 patients with huge HCC who underwent liver resection. RESULTS: Mean(s.d.) tumour diameter was 13.3(3.0) cm; 80 per cent were single lesions. Systematic and non-systematic resections were performed in 80 and 20 per cent of patients respectively, with R0 resection achieved in 86 per cent. Overall 1-, 3- and 5-year disease-free survival rates were 43, 26 and 20 per cent respectively. Risk factors for HCC recurrence were resection margin less than 1 cm and macrovascular invasion. Extensive tumour necrosis of 90 per cent or more after preoperative transarterial chemoembolization was not a prognostic factor. Some 85 per cent of patients with recurrence received various treatments, and these patients had a longer post-recurrence survival than those who were not treated. Overall 1-, 3- and 5-year survival rates were 66, 44 and 31 per cent respectively. CONCLUSION: In patients with huge HCC, hepatic resection combined with active treatment for recurrence resulted in longer-term survival. Frequent protocol-based follow-up appears to be beneficial for the early detection and timely treatment of recurrence.  相似文献   
72.
BACKGROUND: Porcine pancreas is a potential source of material for islet xenotransplantation. However, the difficulty in isolating islets, because of their fragility and the variability of isolation outcome in donor age and breed, represents a major obstacle to porcine islet xenotransplantation. In this study, we compared the islet isolation yield of specific pathogen-free (SPF) Chicago Medical School (CMS) miniature pigs with that of another miniature pig breed and market pigs from a local slaughterhouse. METHODS: Nine adult CMS miniature (ACM) pigs (>12 months), six young CMS miniature (YCM) pigs (6-7 months), four adult Prestige World Genetics (PWG) miniature (APM) pigs (>12 months), and 13 adult market (AM) pigs from a local slaughterhouse were used for islet isolation. RESULTS: The islet yield per gram of pancreas from ACM pigs (9589 +/- 2823 IEQ/g) was significantly higher than that from APM pigs (1752 +/- 874 IEQ/g, P < 0.05), AM pigs (1931 +/- 947 IEQ/g, P < 0.05), or YCM pigs (3460 +/- 1985 IEQ/g, P < 0.05). Isolated islets from ACM pigs were significantly larger than those from AM pigs or YCM pigs. The in vitro and in vivo function of isolated islets showed no difference among experimental groups. The pancreases of ACM pigs contained higher mean islet volume density percentages and larger size of islets than those of AM or APM pigs. CONCLUSIONS: We isolated extremely high yields of well-functioning islets from ACM pigs bred under SPF conditions. SPF CMS miniature pigs should be one of the best porcine islet donors for clinical porcine islet xenotransplantation.  相似文献   
73.
Salvage liver transplantation has been performed for recurrent hepatocellular carcinoma (HCC) or deterioration of liver function after primary liver resection. Because prior liver resection per se is an unfavorable condition for living donor liver transplantation (LDLT), we assessed the technical feasibility of LDLT after prior hepatectomy, and we compared the outcome of salvage LDLT with that of primary LDLT in HCC patients. Of 342 patients with HCC, 17 (5%) underwent salvage LDLT, with 5 having undergone prior major liver resection and 12 prior minor resection. During salvage LDLT, 12 patients received right lobe grafts, 3 received left lobe grafts, and 2 received dual grafts. There was 1 incident (5.9%) of perioperative mortality. Recipient operation time was not prolonged in patients undergoing salvage LDLT, but bleeding complications occurred more frequently than in patients undergoing primary LDLT. Overall survival rates after salvage LDLT were similar to those after primary LDLT, especially when the extent of recurrent tumor was within the Milan criteria. These results indicate that every combination of prior hepatectomy and living donor liver graft is feasible for patients undergoing salvage LDLT, and the acceptable extent of HCC for salvage LDLT is equivalent to that for primary LDLT.  相似文献   
74.
OBJECTIVE: Traumatic vertebral artery injuries pose difficulty in early diagnosis and management because of concomitant neurologic dysfunction and limitations in direct surgical access. The purpose of this report is to review endovascular therapy in patients with traumatic vertebral artery injuries for preservation of the parent artery, and to determine the safety and efficacy of such endovascular therapy. METHODS: Six patients with traumatic vertebral artery lesions were treated using therapeutic endovascular methods. Endovascular therapy was accomplished by stent insertion or coil embolization or both. RESULTS: Except one patient who underwent coil embolization of a transected vertebral artery, all dissections and pseudoaneurysms were successfully treated by stent placement or stent-assisted coiling with preservation of parent arteries. No additional surgical procedures for vascular lesions were required. There were no delayed neurologic or vascular complications and no lesions recurred during the follow-up period (mean, 36.7 months). CONCLUSION: The author's experience demonstrates that endovascular therapy using stents and coils is both feasible and safe in the treatment of traumatic vertebral artery injuries. Endovascular therapy selectively eliminated the vascular abnormality while maintaining the normal patency of the cerebral arteries. Long-term follow-up review of these repairs will be necessary to provide a full evaluation of the safety and efficacy of these devices.  相似文献   
75.

Background

Unplanned re-exploration of the craniotomy after surgical treatment of unruptured intracranial aneurysms (UIAs) is sometimes required, but the underlying causes and rates of these procedures are seldom reported. This study retrospectively analyzed the causes of such re-explorations to identify methods for decreasing their necessity.

Method

From January 2000 to December 2011, 1,720 patients with a total of 1,938 UIAs underwent surgical treatment at our institution. From this cohort, 26 patients (1.5 %) with 38 UIAs required re-exploration. Clinical data, aneurysm characteristics, treatment methods, and the incidence and causes of re-exploration of the craniotomy were analyzed for these 26 patients.

Results

Several causes of re-exploration were identified: compromised distal blood flow (eight patients, 0.47 %), hemorrhagic venous infarction (four patients, 0.23 %), brain retraction injury (three patients, 0.17 %), newly identified aneurysms (three patients, 0.17 %), bleeding from an incompletely clipped aneurysm (two patients, 0.12 %), epidural hematoma (two patients, 0.12 %), failed aneurysm clipping (two patients, 0.12 %) and other causes (two patients, 0.12 %). Annual re-exploration incidence rates ranged from 0 to 3.1 %. Annual incidence rates gradually decreased following the introduction of several intraoperative monitoring systems.

Conclusions

Precise surgical planning and careful operative techniques can reduce the incidence of unplanned re-exploration of the craniotomy. The introduction of various intraoperative monitoring systems can also contribute to a reduction in this incidence.  相似文献   
76.
77.

Background

In an effort to expand the deceased donor pool, transplant centers have accepted expanded-criteria donors as appropriate for many of the patients in the deceased donor pool. We investigated expanded-criteria deceased donor kidney transplantation and compared the outcomes of kidney transplantation according to donor types.

Methods

We retrospectively analyzed 88 kidney transplantations performed between June 2006 and December 2012. We divided the patient into 4 groups: SCDD, standard-criteria deceased donor; ECDD, expanded-criteria deceased donor; ECMO, donor under extracorporeal membrane oxygenation support; living donor.

Results

Deceased and living donor kidney transplantations were performed in 52 (59.1%) and 36 (40.9%) cases, respectively. Among deceased donors, 31 (35.2%) were standard-criteria donors and 14 cases (15.9%) were expanded-criteria donors. Seven (8.0%) donors were under extracorporeal membrane oxygenation support. Mean follow-up was 26.1 ± 20 months. Average number of HLA mismatches among the donor types was 3.39, 3.07, 3.0, and 2.94 in SCDD, ECDD, ECMO, and living donor groups, respectively (P = .708). Delayed graft function occurred in 2 (6.9%), 3 (21.4%), 3 (42.9%), and 3 (8.3%) patients in the SCDD, ECDD, ECMO, and living donor groups, respectively (P = .043). Episodes of acute rejection within a year occurred in 14 (45.2%), 2 (14.3%), 1 (14.3%), and 6 (16.7%) patients in the SCDD, ECDD, ECMO, and living donor groups, respectively (P = .029). Renal functions after kidney transplantation at 3 months, 6 months, 9 months, and 1 year were not significantly different according to donor types. Graft survival was not different among the different donor types (87.1%, 92.8%, 85.7%, 91.7% in SCDD, ECDD, ECMO, and living donor groups, respectively; P = .67). Patient survival was not different among the different donor types (87.1%, 92.9%, 100%, 97.2% in SCDD, ECDD, ECMO, and living donor group, respectively; P = .36).

Conclusion

The use of expanded-criteria deceased donor had no impact on graft or patient survival after kidney transplantation.  相似文献   
78.
79.

Purpose

The purpose of this study was to examine the arthroscopic anatomy of posteromedial capsule and magnetic resonance imaging (MRI) findings in internal derangement of the knee joint and to analyze the relationship between popliteal cysts and the posteromedial capsule.

Methods

From 2011 to 2012, a prospective study included 194 knees of consecutive arthroscopic surgeries for assorted knee problems. The anatomy of the posteromedial joint capsule was evaluated arthroscopically and divided into three types by the presence of capsular fold and opening: no capsular fold and no opening (type I), capsular fold without opening (type II), capsular fold with opening (type III). The presence and size of popliteal cyst were documented by MRI.

Results

Type I was observed in 160 knees (82.5 %), type II in 10 (5.1 %) and type III in 24 (12.4 %). Popliteal cysts were found in 25 knees (12.9 %) by MRI. Of these cases, symptomatic popliteal cysts were identified in 12 knees (6.9 %). On 160 knees demonstrated to be type I, only 3 knees (1.9 %) had popliteal cysts in MRI, 6 knees (60 %) in 10 knees of type II and 16 knees (66.7 %) in 24 knees of type III. Therefore, there was a statistically significant relationship between the type of anatomy in the posteromedial capsule and the popliteal cyst (p < 0.001).

Conclusion

An association between popliteal cyst and arthroscopic anatomy of posteromedial capsule was demonstrated. Comprehensive understanding and knowledge of the arthroscopic anatomy of posteromedial capsule would contribute to the arthroscopic approach in understanding the pathogenesis of popliteal cyst.

Study design

Development of diagnostic criteria on basis of consecutive patients.

Level of evidence

2.  相似文献   
80.

Purpose

To understand the long-term surgical outcomes and prognostic factors for the operative treatment of cervical myelopathy (CM) in patients with athetoid cerebral palsy (ACP).

Methods

We retrospectively reviewed 24 patients with ACP who underwent surgery for CM at our hospital between March 2002 and June 2008. All patients had more than 5 years follow-up. Anterior fusion (11 patients), posterior fusion (1 patient), or combined anterior and posterior (AP) fusion (7 patients) and C1-2 fusion (5 patients) surgeries were performed. Surgical outcomes (average follow-up 102 months), as assessed using modified JOA (mJOA) scores, the Neck Disability Index (NDI), and a visual analog scale (VAS) were compared between the preoperative and postoperative states.

Results

Preoperatvie cervical kyphosis decreased mJOA scores significantly. Long-term follow-up clinical outcomes demonstrated that 10 patients showed favorable (excellent and good) outcomes and 11 patients had non-favorable (fair and worse) outcomes. According to the mJOA scores, patients showed postoperative improvement (7.10–10.45). NDI decreased from 68.46 to 31.66. A second operation was done in seven cases due to instrument failure, progressive kyphotic deformities and adjacent segment degeneration. A preoperative botulinum toxin injection significantly decreased (p < 0.05) the incidence of a second operation.

Conclusions

Patients with ACP have high incidence of instrument failure. Strong surgical fixation, bone fusion and perioperative immobilizations using botulinum toxin injection should be carefully planned preoperatively.  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