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   31880篇
  免费   1795篇
  国内免费   570篇
耳鼻咽喉   153篇
儿科学   115篇
妇产科学   53篇
基础医学   1815篇
口腔科学   2024篇
临床医学   2772篇
内科学   1323篇
皮肤病学   30篇
神经病学   603篇
特种医学   1885篇
外国民族医学   2篇
外科学   12743篇
综合类   5930篇
现状与发展   1篇
预防医学   1093篇
眼科学   199篇
药学   1930篇
  60篇
中国医学   1345篇
肿瘤学   169篇
  2024年   111篇
  2023年   525篇
  2022年   1111篇
  2021年   1447篇
  2020年   1431篇
  2019年   1046篇
  2018年   923篇
  2017年   1058篇
  2016年   1225篇
  2015年   1108篇
  2014年   2331篇
  2013年   2259篇
  2012年   2138篇
  2011年   2336篇
  2010年   1909篇
  2009年   1793篇
  2008年   1587篇
  2007年   1610篇
  2006年   1373篇
  2005年   1305篇
  2004年   1075篇
  2003年   803篇
  2002年   620篇
  2001年   538篇
  2000年   400篇
  1999年   377篇
  1998年   290篇
  1997年   261篇
  1996年   185篇
  1995年   149篇
  1994年   125篇
  1993年   109篇
  1992年   79篇
  1991年   69篇
  1990年   45篇
  1989年   37篇
  1988年   42篇
  1987年   36篇
  1986年   40篇
  1985年   46篇
  1984年   34篇
  1983年   46篇
  1982年   46篇
  1981年   44篇
  1980年   34篇
  1979年   20篇
  1978年   17篇
  1977年   9篇
  1976年   17篇
  1975年   16篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
941.
Between 1993 and 2001, we replaced 22 hips in 16 patients with high dislocation of the hip. All but 1 case was due to congenital dislocation. In all cases the femur was osteotomized below the lesser trochanter and a straight uncemented stem inserted in the medullary canal. The acetabular prostheses were inserted at the site of the original acetabulum, usually after augmenting the acetabular rim by using the medial half of the resected proximal femur. The lateral part of the proximal femur with the intact attachment of the gluteus medius muscle was transposed and fixed to the femoral diaphysis thereby restoring direction of muscle pull. The HHS score increased from a median value of 42 points preoperatively to a median of 86 points after median 25 months of follow-up. Limp, which before surgery was severe in all cases, was less marked or had disappeared at follow-up. The legs had been lengthened median 2.5 (1.0–4.5) cm. No postoperative infections occurred. Palsy or loss of sensory function was not observed in any patient. Dislocation was the commonest complication. It occurred in 3 hips, 2 of which had to be revised to ensure stability.  相似文献   
942.
《Acta orthopaedica》2013,84(6):865-871
Forty femoral neck fractures were followed for 5 years in a prospective clinical, roentgenographic and scintimetric investigation. Thirteen cases had uncomplicated healing, 22 necrosis and five non-union. The diagnostic value of radiographic changes was analysed with reference to development of necrosis of the femoral head or non-union. Sclerosis of the femoral head, and compression and displacement of the fracture were compatible with eventual healing and clinical recovery. Subchondral fracture and collapse of the load-bearing surface, diagnostic for necrosis, were observed in only 7 of 22 cases at 1 year and as late as 3-5 years in three cases. By contrast, four out of five non-union cases were established radiographically within 1 year. Patients needing an arthroplasty after fracture of the femoral neck should be identified on clinical grounds after early radionuclide scintimetry. Waiting for radiographic documentation of necrosis in cases with pain will increase the risk for physical and social impairment associated with poor function of the hip.  相似文献   
943.
944.

Purpose

The goal of this study was to evaluate the treatment and recovery of patients treated for Gartland type III supracondylar humerus fractures in order to determine if postponing treatment leads to a higher rate of open surgical treatment or complications.

Methods

A retrospective study was conducted examining the medical records of children with Gartland type III supracondylar humerus fractures at our institution for a two-year period. The patients included in the study were treated with closed reduction and percutaneous pinning (CRPP) or open reduction and internal fixation (ORIF).

Results

After exclusions, 134 patients were included in the study, with an average age of 5.6 years. The patients were grouped according to whether their treatment was postponed (39.6 %) or immediate (60.4 %). The majority of all patients were treated using CRPP: 46 (86.8 %) of the postponed patients and 75 (92.6 %) of the immediate patients. Very few postsurgical complications occurred in the patients; there was only one (1.6 %) case of iatrogenic nerve injury in a postponed patient as well as four (3.8 %) cases of loss of carrying angle: one (2.3 %) in postponed patients and three (4.8 %) in immediate patients.

Conclusions

Postponing treatment of type III supracondylar humerus fractures in children did not lead to an increase in open surgical treatment; nor did it lead to an increase in complications.  相似文献   
945.

Background

Studies of pediatric and adolescent fractures in general report a significant increase in the incidence of upper-extremity fractures as well as in their surgical treatment. The aim of this study was to determine the trends of the incidence and treatment of distal humeral fractures in hospitalized 0- to 18-year-old patients in Finland.

Method

The study included the entire pediatric and adolescent (<19 years) population in Finland during the 24-year period from 1 January 1987 to 31 December 2010. Data on hospitalized patients were obtained from the nationwide National Hospital Discharge Registry where information is collected from all hospital categories (private, public, and other). Surgical treatment was categorized into three groups; (1) reposition with casting; (2) reposition or reduction and osteosynthesis; (3) reposition or reduction and external-fixation and other fixation methods. Patients were classified into three groups according to age: 0–6 years, 7–13 years, and 14–18 years. Annual incidences were calculated using the annual mid-year population census obtained from the Official Statistics of Finland.

Results

During the 24-year study period, there were a total of 12,590 hospitalizations with a main or secondary diagnosis of distal humeral fracture. In children aged 0–12 years the overall incidence of hospitalization increased 30 % during the 24-year study period, from 4.5 per 10,000 person-years in 1987 to 5.8 per 10,000 person-years in 2010. There were a total of 5,548 operations. During the study period, surgical treatment by repositioning or reduction with osteosynthesis due to a distal humeral fracture increased by fivefold in patients aged <6 years and by twofold in patients aged 7–12 years of age. The incidences of fracture and treatment in children older than 13 years did not change.

Conclusion

The incidence of distal humeral fractures and the incidence of repositioning with osteosynthesis increased remarkably in prepubertal children during the 24-year study period in Finland.  相似文献   
946.
The long-term impact on bone health of lifelong HIV infection and prolonged ART in growing and developing children is not yet known. Measures of bone health in youth must be interpreted in the context of expected developmental and physiologic changes in bone mass, size, density and strength that occur from fetal through adult life. Low bone mineral density (BMD) appears to be common in perinatally HIV-infected youth, especially outside of high-income settings, but data are limited and interpretation complicated by the need for better pediatric norms. The potential negative effects of tenofovir on BMD and bone mass accrual are of particular concern as this drug may be used more widely in younger children. Emphasizing good nutrition, calcium and vitamin D sufficiency, weight-bearing exercise and avoidance of alcohol and smoking are effective and available approaches to maintain and improve bone health in all settings. More data are needed to inform therapies and monitoring for HIV-infected youth with proven bone fragility. While very limited data suggest lack of marked increase in fracture risk for youth with perinatal HIV infection, the looming concern for these children is that they may fail to attain their expected peak bone mass in early adulthood which could increase their risk for fractures and osteoporosis later in adulthood.  相似文献   
947.
Gustilo type IIIC open fractures of the tibia are high-energy injuries necessitating long treatment periods and usually multiple surgical procedures and eventually resulting in high morbidity rates and even amputations. We present here a case involving a type IIIC open tibial fracture with massive loss of the entire tibial diaphysis, which we treated by performing acute tibialization of the fibula after revascularization of the posterior tibial artery in a single-stage emergency operation.  相似文献   
948.
Background and purpose?Incorporation of fresh-frozen allograft bone and safety aspects associated with this procedure can be improved by removing blood and lipids from the bone. We investigated in a quantitative manner how efficient pulse lavage might be for removal of adipose tissue from morselized allograft bone.

Methods?Depending on the study, the washing was performed with an average of 0.8 L or 1.6 L of sterile saline at room temperature. Fat content of the morselized bone samples was determined using hexane elution. The efficiency of pulse lavage alone was compared with that after an additional wash in 12 L of warm water (55°C). Unprocessed controls were also included for comparison.

Results?Pulse lavage with 0.8 L saline alone removed 80% of the fat from the bone, whereas 95% of the fat was removed when washing was performed with 1.6 L of saline. The cleansing efficacy was improved further when an additional wash with warm water was used.

Interpretation?Our results indicate that pulse-lavage washing alone at room temperature is an effective method for defatting of morselized allograft bone, but an additional wash with warm water improves the cleansing efficiency. Pulse lavage is easily available and simple to use in the operating theater.  相似文献   
949.
《Acta orthopaedica》2013,84(4):441-447
Background and purpose Pain after total knee arthroplasty (TKA) is usually severe, and epidural analgesia or femoral nerve block has been considered to be an effective pain treatment. Recently, local infiltration analgesia (LIA) has become increasingly popular but the outcome of this method regarding the analgesic effect has not been fully evaluated. We compared local infiltration analgesia and femoral block with regard to analgesia and morphine demand during the first 24 h after TKA.

Methods 40 patients undergoing TKA under spinal anesthesia were randomized to receive femoral nerve block (group F) or peri- and intraarticular infiltration analgesia (group LIA) with a mixture containing ropivacaine, ketorolac, and epinephrine. All patients had access to intravenous patient-controlled analgesia (PCA) with morphine postoperatively. Pain intensity at rest and upon movement was assessed on a numeric rating scale (0–10) on an hourly basis over 24 h if the patients were awake.

Results The average pain at rest was marginally lower with LIA (1.6) than with femoral block (2.2). Total morphine consumption per kg was similar between the 2 groups. Ancillary analysis revealed that 1 of 20 patients in the LIA group reported a pain intensity of > 7 upon movement, as compared to 7 out of 19 in the femoral block group (p = 0.04).

Interpretation Both LIA and femoral block provide good analgesia after TKA. LIA may be considered to be superior to femoral block since it is cheaper and easier to perform.  相似文献   
950.
《Acta orthopaedica》2013,84(6):485-491
Unilateral tibial fractures were produced in adult, 1-year-old, male Sprague-Dawley rats. The animals were then treated for 6 weeks with daily doses of 2.5 μg, 1.25 μg or 0.125 μg 1α-hydroxycholecalciferol (1α-OH-D3). The aim of the investigation was to study the effect of this treatment on the healing process of the fracture and on the composition of the fractured bone.

The general effect of 2.5 μg of 1α-OH-D3 was a significant loss of body weight (20 per cent) and hypercalcaemia. The lower close levels, however, did not affect the body weight, and with a dose of 0.125 μg the serum calcium level did not increase significantly.

The healing rate of the fractures increased in all treatment groups as compared with the controls. The water content of the fractured tibias increased in the rats treated with 2.5 μg doses but decreased in the other groups. On the other hand the mineral content increased in the groups treated with 1.25 μg and 0.125 μg doses and decreased in the largest dose group. Furthermore the amount of organic material per wet weight increased with the 2.5 μg dose and was mainly unchanged in the other groups. The hydrated bone density and the conical thickness of the tibia increased most significantly in the group treated with 0.125 μg but the trabecular bone area of the periosteal callus did not increase significantly.

The conclusion is drawn that treatment with small doses of 1α-OH-D3 has a beneficial effect on the healing rate and on the mineralization of the fracture callus, and on cortical bone formation.  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