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   48768篇
  免费   5113篇
  国内免费   2702篇
耳鼻咽喉   462篇
儿科学   969篇
妇产科学   512篇
基础医学   4628篇
口腔科学   810篇
临床医学   7059篇
内科学   5830篇
皮肤病学   818篇
神经病学   2189篇
特种医学   1533篇
外国民族医学   16篇
外科学   3005篇
综合类   10033篇
现状与发展   9篇
一般理论   6篇
预防医学   4916篇
眼科学   1249篇
药学   5918篇
  97篇
中国医学   3299篇
肿瘤学   3225篇
  2025年   11篇
  2024年   601篇
  2023年   880篇
  2022年   1966篇
  2021年   2574篇
  2020年   2141篇
  2019年   1525篇
  2018年   1602篇
  2017年   1720篇
  2016年   1471篇
  2015年   2363篇
  2014年   3069篇
  2013年   3012篇
  2012年   4434篇
  2011年   4631篇
  2010年   3309篇
  2009年   2762篇
  2008年   3002篇
  2007年   2841篇
  2006年   2550篇
  2005年   2114篇
  2004年   1554篇
  2003年   1444篇
  2002年   1076篇
  2001年   908篇
  2000年   715篇
  1999年   540篇
  1998年   297篇
  1997年   285篇
  1996年   187篇
  1995年   164篇
  1994年   145篇
  1993年   76篇
  1992年   112篇
  1991年   84篇
  1990年   56篇
  1989年   60篇
  1988年   37篇
  1987年   39篇
  1986年   26篇
  1985年   34篇
  1984年   14篇
  1983年   10篇
  1982年   10篇
  1981年   17篇
  1979年   13篇
  1978年   9篇
  1975年   10篇
  1974年   9篇
  1973年   11篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
83.

Background

Controversy remains over the surgical management of large osteochondral lesions of the femoral head in young, active patients. The purpose of this study is to assess midterm clinical and radiographic outcomes after fresh osteochondral allograft transplantation (OAT) for large femoral head lesions at minimum 2-year follow-up.

Methods

A retrospective review of prospectively collected data was performed for 22 patients under the age of 50 years with defined femoral head osteochondral lesions who underwent fresh OAT between 2008 and 2015. Patients were assessed clinically using the modified Harris Hip Score (mHHS) preoperatively and at each follow-up visit. Postoperative radiographs were evaluated for graft integrity and Kellgren & Lawrence Grade for osteoarthritis severity. Complications and reoperation were assessed by chart review. Kaplan-Meier survivorship analyses with 95% confidence intervals were performed for the end point of conversion to total hip arthroplasty.

Results

At a mean follow-up of 68.8 months (26-113), the mean mHHS improved significantly (P < .001) from 48.9 (19-84) to 77.4 (35-98). Sixteen of 22 patients (72.7%) had an mHHS ≥70 at the latest follow-up. Arthritic progression, as indicated by an increase in the Kellgren & Lawrence Grade, occurred in 4 of 22 hips (18.2%). Five patients (22.7%) underwent conversion to total hip arthroplasty. Graft survivorship was 86.4 ± 7.3% at 2 years, 78.5 ± 10.0% at 5 years, and 67.3 ± 13.5% at 9 years.

Conclusion

Fresh OAT may be a viable treatment option for osteochondral defects of the femoral head in young, active patients with minimal preexisting joint deformity.  相似文献   
84.
85.
目的评价跟骨解剖型钛板治疗累及关节面的跟骨骨折的临床疗效。方法对38例累及关节面的跟骨骨折患者(42足)采用跟骨解剖型钛板内固定。结果患者均获随访,时间8~18个月。按Maryland足部评分系统评价疗效:优30足,良8足,可4足,优良率90.4%。结论跟骨解剖型钛板治疗累及关节面的跟骨骨折,内固定坚强,可早期功能锻炼,疗效满意。  相似文献   
86.
NLRP3 inflammasome has been recently reported as an important risk factor in the development of cancer. But the relationship between polymorphisms of NLRP3 inflammasome related genes and chronic myeloid leukemia (CML) is rarely reported. Therefore, the aim of the present study was to investigate the association of five genetic polymorphisms (NLRP3, IL-1β, IL-18, CARD8 and NF-κB) in 267 CML patients and 344 healthy controls. We found that the AT genotype of CARD8 (rs2043211) was significantly higher compared to TT genotype in high and intermediate risk CML patients. IL-1β (rs16944) polymorphism in early molecular response at 6?months was marginally different, with more GG and less AA genotype in BCR-ABLIS >1% group. IL-18 (rs1946518) polymorphism was significantly different with more GG genotype in BCR-ABLIS >1% group at 6?months. We also demonstrated that WBC count of newly diagnosed patients carrying AG genotype was significantly higher than that of GG or AA genotype of IL-1β (rs16944). The onset age of patients carrying ins/ins genotype of NF-κB (rs28362491) was significantly older than that of ins/del and del/del genotype. Moreover, IL-1β or NLRP3 mRNA expression was decreased and IL-18 mRNA expression was increased significantly in CML patients compared with controls. In conclusion, the genetic polymorphisms of NLRP3 inflammasome may be served as potential predictors for CML.  相似文献   
87.
Human parainfluenza virus type 3 (hPIV3) is an important respiratory pathogen that causes the majority of viral pneumonia of infants and young children. hPIV3 can infect host cells through the synergistic action of hemagglutinin-neuraminidase (HN) protein and the homotypic fusion (F) protein on the viral surface. HN protein plays a variety of roles during the virus invasion process, such as promoting viral particles to bind to receptors, cleaving sialic acid, and activating the F protein. Crystal structure research shows that HN tetramer adopted a “heads-down” conformation, at least two heads dimmer on flank of the four-helix bundle stalk, which forms a symmetrical interaction interface. The stalk region determines interactions and activation of F protein in specificity, and the heads in down position statically shield these residues. In order to make further research on the function of these amino acids at the hPIV3 HN stalk/head interface, fifteen mutations (8 sites from stalk and 7 sites from head) were engineered into this interface by site-directed mutagenesis in this study. Alanine substitution in this region of hPIV3 HN had various effects on cell fusion promotion, receptor binding, and neuraminidase activity. Besides, L151A also affected surface protein expression efficiency. Moreover, I112A, D120A, and R122A mutations of the stalk region that were masked by global head in down position had influence on the interaction between F and HN proteins.  相似文献   
88.

Background

Whether osteoarthritic patients with mild varus deformity can be indicated for high tibial osteotomy (HTO) is not established. We examined the preoperative characteristics and postoperative outcomes of HTO in patients with mild genu varum compared to patients with greater varus deformity.

Methods

Seventy-one patients who underwent HTO were included in this retrospective study. Patients were divided into either mild varus (MV, mechanical femorotibial angle (mFTA) ≤ 4°, n?=?31 (44%)) and greater varus (GV, mFTA > 4°, n?=?40 (56%)) groups. Preoperative characteristics on single photon emission computed tomography–computed tomography (SPECT–CT), magnetic resonance image and radiograph were evaluated. Alignment parameters and functional outcomes were compared pre- and postoperatively between the groups.

Results

Preoperative characteristics were similar between the two groups, except the severity of arthritis and coronal alignment. There was no difference in the proportion of hot uptake in the medial compartment; medial meniscus posterior horn root tear, complex or radial tear; bone marrow edema. Full-thickness cartilage defect of medial compartment was more frequent and arthritis grade was also more severe in GV group. Coronal alignment of the MV group was corrected into more valgus than the GV group (4.5° vs. 2.8° in mFTA, P?=?0.012). Pre- and postoperative Knee Society knee and function scores were also comparable in the two groups.

Conclusions

Mild varus patients are similar to greater varus patients regarding preoperative features and achieve the comparable functional outcome. A selected subset of osteoarthritic patients with mild varus deformity might be indicated for HTO.

Level of evidence

III (Retrospective comparative study).  相似文献   
89.
90.
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