全文获取类型
收费全文 | 2349323篇 |
免费 | 172983篇 |
国内免费 | 4731篇 |
专业分类
耳鼻咽喉 | 31708篇 |
儿科学 | 73295篇 |
妇产科学 | 63150篇 |
基础医学 | 334780篇 |
口腔科学 | 70086篇 |
临床医学 | 210626篇 |
内科学 | 457663篇 |
皮肤病学 | 52161篇 |
神经病学 | 182972篇 |
特种医学 | 89378篇 |
外国民族医学 | 319篇 |
外科学 | 362041篇 |
综合类 | 52634篇 |
现状与发展 | 4篇 |
一般理论 | 739篇 |
预防医学 | 171046篇 |
眼科学 | 56096篇 |
药学 | 175332篇 |
10篇 | |
中国医学 | 5885篇 |
肿瘤学 | 137112篇 |
出版年
2019年 | 17746篇 |
2018年 | 25948篇 |
2017年 | 19877篇 |
2016年 | 21946篇 |
2015年 | 25049篇 |
2014年 | 34490篇 |
2013年 | 50390篇 |
2012年 | 69617篇 |
2011年 | 73284篇 |
2010年 | 43407篇 |
2009年 | 40841篇 |
2008年 | 69001篇 |
2007年 | 73075篇 |
2006年 | 73985篇 |
2005年 | 70703篇 |
2004年 | 68392篇 |
2003年 | 65117篇 |
2002年 | 63018篇 |
2001年 | 125501篇 |
2000年 | 128634篇 |
1999年 | 106638篇 |
1998年 | 27323篇 |
1997年 | 23878篇 |
1996年 | 23994篇 |
1995年 | 22929篇 |
1994年 | 21028篇 |
1993年 | 19457篇 |
1992年 | 80952篇 |
1991年 | 77956篇 |
1990年 | 75119篇 |
1989年 | 72503篇 |
1988年 | 65991篇 |
1987年 | 64365篇 |
1986年 | 60620篇 |
1985年 | 57618篇 |
1984年 | 42059篇 |
1983年 | 35843篇 |
1982年 | 19733篇 |
1979年 | 37340篇 |
1978年 | 25642篇 |
1977年 | 21839篇 |
1976年 | 20014篇 |
1975年 | 21354篇 |
1974年 | 25873篇 |
1973年 | 24789篇 |
1972年 | 23151篇 |
1971年 | 21592篇 |
1970年 | 20270篇 |
1969年 | 18959篇 |
1968年 | 17567篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
S.A. GEORGE D.J. BILSLAND N.J. WAINWRIGHT J. FERGUSON 《The British journal of dermatology》1993,128(3):301-305
Despite a widely held belief that the use of emollients prior to broad-band UVB irradiation accelerates clearance of psoriasis, only one single-blind controlled study exists in support of this. No similar study has been carried out with photochemotherapy (PUVA) or narrow-band UVB (311–313 nm) phototherapy. As some emollients absorb UV radiation, and thereby inhibit psoriasis clearance, there is a need to identify emollients suitable for pre-irradiation use. Coconut oil may be useful in this respect. In two randomized groups of patients with chronic plaque psoriasis undergoing either routine PUVA(n=14) or narrow-band UVB phototherapy (n=15), a single-blind controlled (half-body) study was undertaken to assess the died of pre-irradiation application of coconut oil. Patients were given PUVA twice weekly, or TL-01 therapy thrice weekly. The initial UV dose was 70% of previously determined minimal phototoxic (MPD) or minimal erythema doses (MED), with 40% incremental steps at each visit (reduced if adverse effects occurred). Psoriasis severity was scored on each side after every three treatments. No significant acceleration of psoriasis clearance was seen in either group. We do not, therefore, recommend the routine use of emollients prior to PUVA or TL-01 therapy when using near erythemogenic irradiation regimens. 相似文献
992.
Corpus cavernosography in a patient with erectile dysfunction revealed absence of communication between the 2 cavernous bodies. No similar case was found in a review of 100 consecutive cavernosograms or in the literature. The abnormality may be a source of error in pressure recordings or in intravenous injection of pharmaceutical agents. 相似文献
993.
The ileocecal reservoir (Indiana pouch) is a large volume, low pressure continent reservoir well suited for urinary diversion. The mechanism of continence is believed to be the result of several factors, including the natural ileocecal valve resistance, resistance produced by the plication of the ileal segment and normal peristalsis of the ileum. We report the results of a video-urodynamic study in patients with an Indiana pouch, aimed at establishing the factors that contribute to continence and their relative significance. Video-urodynamic studies clearly demonstrate that continence in this type of urinary reservoir is dependent upon a synergism of the aforementioned factors in combination with the low intraluminal pressure of the detubularized bowel. Video-urodynamic studies offer an objective demonstration of the reservoir dynamics and its continence mechanisms, and provide an insight into the possible etiology of incontinence. Such studies also offer an objective means for critical comparison of the different continent urinary reservoirs. 相似文献
994.
A new technique for assessing the efferent innervation of the human striated urethral sphincter 总被引:4,自引:0,他引:4
A technique is described for recording the electromyographic response of the striated urethral sphincter to transcutaneous magnetic stimulation of the brain and spinal cord. A series of 11 control patients have been studied and 3 examples of patients with neurological disease also are reported. The most reliable response was recorded after facilitated transcranial stimulation of the cerebral cortex, with the mean latency of the electromyographic response in the striated sphincter being 26.4 msec. (standard deviation 2.21). It is concluded that assessment of the latency of the striated urethral sphincter electromyographic response to transcranial magnetic stimulation may be a useful technique in the investigation of patients with disorders of micturition. 相似文献
995.
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
996.
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
997.
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
998.
Clinical experience with immediate breast reconstruction using tissue expansion or transverse rectus abdominis musculocutaneous flaps 总被引:5,自引:0,他引:5
We retrospectively reviewed our experience with immediate breast reconstruction in 103 consecutive patients with stage 0 or I breast carcinoma between May 1983 and April 1988. Two reconstructive techniques were used, that is, either tissue expansion with secondary prosthesis implantation (60%) or transverse rectus abdominis musculocutaneous (TRAM) flap (40%). Chemotherapy was administered in 22% of patients without delay or compromise. The mean length of follow-up is 30 months. The complication rate was equal for both groups (24%) with infection being most common in the group of patients with tissue expansion and partial flap necrosis being most common in the group of patients with TRAM flaps. Aesthetic results were superior with use of the TRAM flap. Our experience concurs with previous reports that documented satisfactory results with immediate breast reconstruction without compromising further therapy. We conclude that although the tissue expansion technique yields acceptable results, the TRAM flap yields superior aesthetic results in terms of both appearance and consistency. 相似文献
999.
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
1000.
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