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   1603909篇
  免费   131664篇
  国内免费   2584篇
耳鼻咽喉   21659篇
儿科学   52985篇
妇产科学   46379篇
基础医学   227980篇
口腔科学   47233篇
临床医学   141269篇
内科学   315146篇
皮肤病学   34103篇
神经病学   130269篇
特种医学   64756篇
外国民族医学   474篇
外科学   243988篇
综合类   39752篇
现状与发展   3篇
一般理论   548篇
预防医学   123144篇
眼科学   36485篇
药学   121623篇
  3篇
中国医学   2976篇
肿瘤学   87382篇
  2018年   14798篇
  2016年   12924篇
  2015年   15077篇
  2014年   20707篇
  2013年   31456篇
  2012年   42668篇
  2011年   44861篇
  2010年   26429篇
  2009年   25370篇
  2008年   43089篇
  2007年   45341篇
  2006年   46157篇
  2005年   44762篇
  2004年   44193篇
  2003年   42280篇
  2002年   41387篇
  2001年   75753篇
  2000年   78402篇
  1999年   66469篇
  1998年   17765篇
  1997年   16353篇
  1996年   16332篇
  1995年   16037篇
  1994年   15079篇
  1993年   14230篇
  1992年   55467篇
  1991年   53818篇
  1990年   52605篇
  1989年   50860篇
  1988年   47255篇
  1987年   46590篇
  1986年   44310篇
  1985年   42865篇
  1984年   32063篇
  1983年   27581篇
  1982年   16161篇
  1981年   14451篇
  1980年   13572篇
  1979年   30479篇
  1978年   21078篇
  1977年   17783篇
  1976年   16711篇
  1975年   17594篇
  1974年   21503篇
  1973年   20683篇
  1972年   18864篇
  1971年   17775篇
  1970年   16306篇
  1969年   15284篇
  1968年   13955篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
181.
182.
183.
Recurrent dislocation of the patella and the Goldthwait operation   总被引:1,自引:0,他引:1  
In this study 17 patients with recurrent dislocation of the patella were followed up 10 years after their Goldthwait operation. The subjective and clinical findings were excellent or good in 70%. X-radiographs indicated osteoarthritis of the femoropatellar joint in 60%. Concerning the aetiopathological factors, we found an increased external torsion of the afflicted extremity (measured by computed tomography).  相似文献   
184.
The pulsed tunable dye laser (PTDL) is generally considered to have a very low incidence of adverse effects, allowing it to become the treatment of choice for the majority of port wine stains (PWS). The low incidence of adverse effects has led to difficulties in determining the true incidence and type of adverse effect seen with this laser. We therefore undertook a retrospective study of 701 patients with PWS, who received 3877 full treatments to determine the incidence and type of adverse effects seen following treatment with the PTDL. Blistering and crusting were seen in 5·9% and 0·7% of patients, respectively, but were transient events which usually healed without permanent sequelae. Hyperpigmentation was the most frequently observed adverse effect seen in 9·1% of patients but generally showed gradual resolution over 6–12 months. Hypopigmentation was infrequent, seen in 1.4% of patients. The most significant adverse effects were atrophic and hypertrophic scarring seen in 4·3% and 0·7% of patients, respectively. Our observations show that there is a small but definite risk of atrophic scarring with a predisposition for younger patients. Hypertrophic scarring can occur albeit rarely and there may be a predisposition towards the neck. In most cases test areas were not predictive of scarring. This underlines the need for a full discussion of scarring risk in patients with PWS undergoing treatment with the PTDL.  相似文献   
185.
SUMMARY Current standard specifications for the laboratory evaluation of denture base materials require subjective assessment of colour stability. This study evaluates a new objective measurement technique for translucent denture base materials, by comparing quantitative data with the results obtained from a standard subjective method. Preliminary work on three representative commercial acrylic materials resulted in the selection of a white background for the quantification of colour change of these translucent materials. One half of each sample was exposed to artificial sunlight for 24 h.
The colour of both exposed and unexposed resin was measured on the CIE L*a*b* scale using a photoelectric colorimeter. Significant changes in the b* and E* values (P < 0.001) were observed following light exposure. Objective data for a wide range of commercial materials were compared with the results of a subjective evaluation and it was shown that a change in b* of 1.5 units was discernable subjectively by eye for 100% of the cases. It is suggested that this method and limit value could form the basis of a new objective colour change specification for polymeric dental materials.  相似文献   
186.
187.
Three patients who experienced premature complete physeal closure of the ipsilateral limb following diaphyseal fractures are reported. The diagnosis was recognized because of unexpected progressive limb length discrepancy following fracture healing. The cause is unknown. This phenomenon should be recognized by those treating fractures in children.  相似文献   
188.
A study was carried out in order to document any abnormalities in the electro-encephalogram (EEG) that might appear in young adolescents who have deliberately inhaled the range of volatile substances loosely referred to as 'glue'. The EEGs of a group of 'street children' being assisted in a Johannesburg shelter were examined. The records were analysed for any clinical abnormalities and also subjected to spectral analysis in order to examine the overall characteristics of frequency, power and spatial distribution. The EEGs clearly revealed that, although at the time of the examination the subjects were ostensibly abstinent, both clinical and normative evidence of continuing brain disturbance was present. It was concluded that glue sniffing is likely to have long term electrocerebral sequelae.  相似文献   
189.
Gonadoblastoma, a rare gonadal neoplasm, presents most frequently in phenotypic female or phenotypically male patients with dysgenetic gonads or undescended testes. To date, only 2 cases of gonadoblastoma have been reported in anatomically normal male patients with scrotal testes. Both of these patients presented with testicular masses and germ cell tumors. We report a case of a genotypically and phenotypically normal, fertile man with descended testes who on evaluation for chronic orchialgia had a gonadoblastoma unaccompanied by a germ cell neoplasm. The tumor was nonpalpable and was initially discovered on scrotal ultrasound.  相似文献   
190.
Gallstone dissolution   总被引:2,自引:0,他引:2  
Many methods are available for gallstone dissolution, including oral bile salts; cholesterol solvents such as mono-octanoin or methyl tert-butyl either; and calcium or pigment solvents such as EDTA and polysorbate. Which of these approaches will be appropriate for an individual patient depends on the type of stones; whether they are in the gallbladder or the bile ducts; whether access to the biliary tree is available; the patient's age and general medical condition; and the availability of necessary expertise. In the US, both chenodeoxycholate and ursodeoxycholate are now available. Ursodeoxycholate is more expensive but appears to produce fewer side effects and may be more efficacious. These agents are most effective in thin women with small floating, radiolucent cholesterol stones in a functioning gallbladder. Only about half of the small subset of patients will experience partial or complete dissolution of stones within a year. Stone recurrence and the potential toxicity of long-term therapy are problems with this approach. Therefore, for most patients, cholecystectomy, either in the traditional fashion or using a laparoscopic approach (see article later in this issue by Gadacz et al), is the most cost-effective and perhaps the safest option. Intragallbladder instillation of methyl tert-butyl ether probably will be applicable only to a small subset of patients, and treatment is likely to be followed by a high recurrence rate. In patients with retained common duct cholesterol stones and access to the biliary tree, mono-octanoin therapy is advantageous in that it can be initiated as soon as cholangiography demonstrates no extravasation. In properly selected patients, a 90% success rate with this technique can be expected within 7 days.  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