全文获取类型
收费全文 | 1601633篇 |
免费 | 131501篇 |
国内免费 | 2581篇 |
专业分类
耳鼻咽喉 | 21646篇 |
儿科学 | 52932篇 |
妇产科学 | 46226篇 |
基础医学 | 227761篇 |
口腔科学 | 47199篇 |
临床医学 | 140904篇 |
内科学 | 314759篇 |
皮肤病学 | 34090篇 |
神经病学 | 130103篇 |
特种医学 | 64721篇 |
外国民族医学 | 474篇 |
外科学 | 243794篇 |
综合类 | 39712篇 |
现状与发展 | 3篇 |
一般理论 | 544篇 |
预防医学 | 122856篇 |
眼科学 | 36470篇 |
药学 | 121257篇 |
3篇 | |
中国医学 | 2974篇 |
肿瘤学 | 87287篇 |
出版年
2018年 | 14764篇 |
2016年 | 12900篇 |
2015年 | 15026篇 |
2014年 | 20646篇 |
2013年 | 31350篇 |
2012年 | 42546篇 |
2011年 | 44748篇 |
2010年 | 26335篇 |
2009年 | 25302篇 |
2008年 | 42996篇 |
2007年 | 45239篇 |
2006年 | 46048篇 |
2005年 | 44671篇 |
2004年 | 44089篇 |
2003年 | 42177篇 |
2002年 | 41289篇 |
2001年 | 75681篇 |
2000年 | 78325篇 |
1999年 | 66387篇 |
1998年 | 17731篇 |
1997年 | 16334篇 |
1996年 | 16314篇 |
1995年 | 16019篇 |
1994年 | 15070篇 |
1993年 | 14217篇 |
1992年 | 55427篇 |
1991年 | 53775篇 |
1990年 | 52561篇 |
1989年 | 50832篇 |
1988年 | 47221篇 |
1987年 | 46560篇 |
1986年 | 44284篇 |
1985年 | 42844篇 |
1984年 | 32034篇 |
1983年 | 27565篇 |
1982年 | 16144篇 |
1981年 | 14436篇 |
1980年 | 13564篇 |
1979年 | 30460篇 |
1978年 | 21064篇 |
1977年 | 17764篇 |
1976年 | 16694篇 |
1975年 | 17574篇 |
1974年 | 21486篇 |
1973年 | 20672篇 |
1972年 | 18853篇 |
1971年 | 17771篇 |
1970年 | 16289篇 |
1969年 | 15268篇 |
1968年 | 13949篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
191.
R K Beals 《Journal of pediatric orthopedics》1990,10(6):717-720
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
192.
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
193.
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
194.
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
195.
Technetium-99-labelled methylene diphosphonate uptake scans in patients with dialysis arthropathy 总被引:1,自引:0,他引:1
Patients on long-term haemodialysis suffer from dialysis arthropathy due to the deposition of dialysis amyloid. We investigated the use of 99Tc-labelled methylene diphosphonate bone scans in 17 patients as a possible in vivo diagnostic technique. In most clinically affected joints, with the exception of shoulders and hands, there was increased radioisotope uptake consistent with uptake by periarticular bone. In addition, we describe intense soft-tissue uptake around some clinically affected large joints. In contrast, control groups of patients on haemodialysis without arthropathy and patients without renal failure did not have increased uptake. A semi-quantitative scale of uptake was devised, and the following correlations were significant: pain perception and isotope uptake score in the ankles and feet, and the number of radiological lesions and isotope uptake scores in the wrists and knees. The following sites where the radioisotope might bind in the affected joints are proposed: amyloid deposits, areas of soft-tissue calcification, or areas of increased bone turnover. It is concluded that whereas the scanning technique cannot make a definite diagnosis of amyloid and, therefore, cannot be expected to supersede histological diagnosis, it is a useful adjuvant investigation, of particular importance in those patients unable or unwilling to undergo biopsy. 相似文献
196.
G Hasselgren R Jerre M Ullman A T?rnvall S Edshage 《The Journal of hand surgery, European volume》1990,15(1):35-39
Eleven patients with lunatomalacia were treated by excision of the lunate and instillation of liquid silicone. The silicone vulcanised and formed an in-situ molded prosthesis. The patients were reexamined after a mean of 7.1 years. Four patients were pain-free and two had pain only at work; three had not been improved by the operation and two had undergone arthrodesis. The patients with good results all belonged to group IV pre-operatively. Surprisingly, no patient showed any sign of silicone synovitis, although all the prostheses except one had either fractured or deformed. The reasons for this are discussed and the indications for the operation established. 相似文献
197.
Summary This study explores the effects of a calcium-deficient diet on patterns of bone remodeling, and examines regional differences
in the amount of bone lost. Skeletally mature female rabbits (n=6) were fed a calcium-deficient diet (0.10% Ca2+ and 0.50% P) for 14 weeks. A separate group of rabbits (n=4) were fed a maintenance diet (1.2% Ca2+ and 0.45% P). Bone mineral content, serum calcium, and serum phosphorus were measured each week during the experimental period.
Following sacrifice, the L3 vetebra, femoral head, proximal tibial metaphysis, and tibial midshaft were analyzed histomorphometrically. Rabbits had 20%
less vertebral bone after only 14 weeks of a calcium-deficient diet. As in human postmenopausal osteoporosis, bone loss in
calcium-deficient rabbits occurs in the trabecular bone of the lumbar spine before that in the trabecular bone of the lower
extremity. Calcium-deficient diets alone do not lead to increased osteoid volume or thickness. Because bone loss is relatively
rapid and because the pattern of loss is similar in some respects to that found in humans, adult rabbits may provide an attractive
model of calcium deficiency osteoporosis in a skeletally mature mammal in which remodeling is predominant over modeling. 相似文献
198.
T. M. Skerry M.D. M.R.C.V.S. R. Suswillo A. J. El Haj N. N. Ali R. A. Dodds L. E. Lanyon 《Calcified tissue international》1990,46(5):318-326
Summary Previous studies of Alcian blue-induced birefringence in adult avian cortical bone showed that a short period of intermittent
loading rapidly produces an increased level of orientation of proteoglycans within the bone tissue. In the absence of further
loading, this persists for over 24 hours. We have proposed that this phenomenon could provide a means for “capturing” the
effects of transient strains, and so provide a persistent, constantly updated strain-related influence on osteocyte populations
related to the bones' averaged recent strain history, in effect, a “strain memory” in bone tissue. In our present study, we
use the Alcian blue-induced birefringence technique to demonstrate that proteoglycan orientation also occurs after intermittent
loading of both cortical and cancellous mammalian bonein vivo andin vitro. We also show that the change in birefringence is proportional to the magnitude of the applied strain, and that the reorientation
occurs rapidly, reaching a maximal value after only 50 loading cycles. Examination of electron micrographs of bone tissue
after staining with cupromeronic blue allows direct visualization and quantification of the change in proteoglycan orientation
produced by loading. This shows that intermittent loading is associated with a realignment of the proteoglycan protein cores,
bringing them some 5 degrees closer to the direction of collagen fibrils in the bone matrix. 相似文献
199.
John R. Jarrett M.D. 《Aesthetic plastic surgery》1990,14(1):87-92
Immediate reconstruction of more than 1000 breasts was performed on high-risk patients on whom a prophylactic mastectomy was done. The mastectomy removes as much breast tissue as possible while leaving sufficient skin, and possibly the nipple-areola complex, to enable immediate reconstruction. The creation of symmetrical, well-balanced muscle pockets for the implant is the most important factor in producing satisfactory results in these cases. 相似文献
200.
Extravesical versus Leadbetter-Politano ureteroneocystostomy: a comparison of urological complications in 320 renal transplants 总被引:3,自引:0,他引:3
The urological complications of 320 consecutive renal transplants performed at our institution between October 17, 1985 and November 10, 1989 are reviewed. The Leadbetter-Politano technique of ureteroneocystostomy was used in the first 160 patients (group 1) and an anterior extravesical technique modified from the methods of Witzel, Sampson and Lich was performed in the second 160 patients (group 2). Urological complications occurred in 15 patients (9.4%) in group 1 and 6 (3.7%) in group 2 (p = 0.04). Ureterovesical junction obstruction occurred in 6 patients (3.7%) in group 1 and 1 (0.6%) in group 2 (p = 0.05). Complications of leakage, ureteral necrosis and ureteral stricture were comparable in the 2 groups. Therefore, we advocate the use of the anterior extravesical technique over Leadbetter-Politano ureteral reimplantation based on the lower incidence of urological complications and various technical advantages, including less operative time, avoidance of a separate cystotomy, less hematuria and ability to use short donor ureters. 相似文献