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   1930篇
  免费   170篇
  国内免费   27篇
耳鼻咽喉   9篇
儿科学   148篇
妇产科学   27篇
基础医学   238篇
口腔科学   117篇
临床医学   181篇
内科学   346篇
皮肤病学   210篇
神经病学   47篇
特种医学   177篇
外科学   285篇
综合类   39篇
预防医学   102篇
眼科学   41篇
药学   56篇
  1篇
中国医学   2篇
肿瘤学   101篇
  2024年   7篇
  2023年   18篇
  2022年   16篇
  2021年   38篇
  2020年   25篇
  2019年   14篇
  2018年   61篇
  2017年   50篇
  2016年   44篇
  2015年   67篇
  2014年   93篇
  2013年   130篇
  2012年   77篇
  2011年   56篇
  2010年   93篇
  2009年   101篇
  2008年   46篇
  2007年   59篇
  2006年   66篇
  2005年   42篇
  2004年   44篇
  2003年   38篇
  2002年   35篇
  2001年   30篇
  2000年   26篇
  1999年   41篇
  1998年   112篇
  1997年   93篇
  1996年   101篇
  1995年   66篇
  1994年   78篇
  1993年   42篇
  1992年   20篇
  1991年   23篇
  1990年   13篇
  1989年   33篇
  1988年   30篇
  1987年   28篇
  1986年   26篇
  1985年   24篇
  1984年   13篇
  1983年   9篇
  1982年   21篇
  1981年   15篇
  1980年   16篇
  1979年   5篇
  1978年   7篇
  1977年   9篇
  1976年   13篇
  1975年   9篇
排序方式: 共有2127条查询结果,搜索用时 0 毫秒
91.
Objective:To create and validate two new Image Receptor-Holding devices (IRHDs) to reduce proximal surfaces overlapping in bitewing radiography in comparison to a regular well-established and commercially available IRHD.Methods:Two IRHDs for bitewing radiographs with a wedge on the biting surface were designed and 3D-printed. These IRHDs, with a large wedge (Pr-Lw) and small wedge (Pr-Sw), were compared with a regular commercially available IRHD (Rinn XCP®) during image acquisition of bitewing radiographs of four posterior regions (one upper region and three lower regions) in two dry skulls and mandibles. A total of 156 interproximal regions on bitewing radiographs were radiographed by 13 oral radiology graduate students and independently assessed by two oral radiologists (10 years of experience). IRHDs were compared by Cochran’s Q test regarding the number of overlapped proximal surfaces in the acquired radiographs with a significance level of 5%.Results:The observers were in perfect agreement (κ = 1.0) to classify the proximal surfaces overlapping. The Pr-Lw IRHD presented the lowest number of surfaces overlapping (19.2%) followed by the Pr-Sw IRHD (48.1%) and the XCP®IRHD with the highest surfaces overlapping (71.2%). The Pr-Lw IRHD surfaces overlapping was statistically different from the XCP IRHD (p < 0.001), and the Pr-Sw IRHD (p = 0.014).Conclusions:The Pr-Lw IRHD demonstrated the most efficient performance in overlapping surfaces reduction, compared with the Pr-Sw IRHD and the XCP® IRHD in adult dry skulls and mandibles.  相似文献   
92.

Background

Ankylosing spondylitis (AS) is a chronic inflammatory disease with multiple articular and para-articular involvement that has a predilection for the axial skeleton. In spite of its high prevalence, ankylosis secondary to AS is a rare condition.

Case report

A 31-year-old male diagnosed with AS was referred for computed tomography (CT) of the temporomandibular joint (TMJ) due to severe mouth opening limitation. The patient had a 16-year medical history of AS and sought assistance due to TMJ pain and incapacity to open his mouth.

Results

Previous bony scintigraphy revealed involvement of the spine, sacroiliac joints, right knee, and left TMJ. Magnetic resonance imaging revealed erosion of the left condyle and posterior slope of the articular eminence, and a mass of heterogeneous signal intensity between these structures. The left condyle also presented sclerosis/edema of the bone marrow and the disk could not be identified. Sagittal and coronal CT images showed moderate alterations of the TMJ on the right side. On the left side, the images displayed markedly eroded condyle and mandibular fossa, and a bony mass resulting in ankylosis of the osseous components of the joint.

Conclusion

TMJ ankylosis in AS patients is rare and very few reports have presented imaging features of the condition through advanced diagnostic techniques.  相似文献   
93.
Lipids extracted with chloroform-methanol from red blood cell membranes of 7 PNH and 13 control subjects were used for the preparation of liposomes, which were then examined with the reactive lysis test. PNH liposomes lysed to a higher extent than control liposomes as indicated by the higher dilution of the limiting complement reagent that was necessary to lyse 50% of the PNH liposomes. A similar finding was also observed with liposomes made of lipids from AET-treated red cells. The enhanced reactive lysis can be attributed to the polar lipid fraction, as indicated by the increased lysis of hybrid liposomes prepared from this polar lipids extracted from PNH erythrocyte membrane and lipids extracted from normal erythrocyte membrane. The increased susceptibility to reactive lysis does not seem to be specific of PNH liposomes, since it was also observed with liposomes prepared from lipids of red cells from beta-thalassemia major and autoimmune hemolytic disease.  相似文献   
94.
95.
Papillary cystadenoma is a rare, benign salivary gland tumor which is well-circumscribed, containing cystic cavities with intraluminal papillary projections. Only 19 cases arising within minor salivary glands (MnSG) from the oral cavity sites have been reported in the English literature (PubMed 1958–2014). We report 11 new cases of MnSG papillary cystadenomas in conjunction with a review of the literature. Demographic information, clinical and histologic features, treatment and prognosis are compiled and discussed for all 30 cases reported in the English literature.  相似文献   
96.
97.
98.
99.

Two principles should underpin the provision of primary health care to refugees: (a) that refugees should have the same access to quality primary care services as the local population, and (b) any specialist service should have the goal of full integration of the refugee into normal general practice. The various ways in which medical care can be provided to refugees and the knowledge, skills and attitudes important to such provision are described. One way in which such a service was provided in east Kent is reported. The term ‘refugee’ encompasses newly arrived refugees who are awaiting a decision from the Home Office, as well as those who have been given permission to stay, either as recognized Refugees under the provisions of the 1951 United Nations Convention, or with Exceptional or Indefinite Leave to Remain.  相似文献   
100.
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