全文获取类型
收费全文 | 1244566篇 |
免费 | 84304篇 |
国内免费 | 5453篇 |
专业分类
耳鼻咽喉 | 17274篇 |
儿科学 | 35951篇 |
妇产科学 | 35194篇 |
基础医学 | 174411篇 |
口腔科学 | 35596篇 |
临床医学 | 102875篇 |
内科学 | 252691篇 |
皮肤病学 | 26607篇 |
神经病学 | 96018篇 |
特种医学 | 49149篇 |
外国民族医学 | 418篇 |
外科学 | 196925篇 |
综合类 | 29577篇 |
现状与发展 | 4篇 |
一般理论 | 307篇 |
预防医学 | 80601篇 |
眼科学 | 28865篇 |
药学 | 92577篇 |
23篇 | |
中国医学 | 4461篇 |
肿瘤学 | 74799篇 |
出版年
2019年 | 9082篇 |
2018年 | 13308篇 |
2017年 | 10464篇 |
2016年 | 11009篇 |
2015年 | 12694篇 |
2014年 | 17866篇 |
2013年 | 25998篇 |
2012年 | 35031篇 |
2011年 | 36857篇 |
2010年 | 22424篇 |
2009年 | 21242篇 |
2008年 | 34752篇 |
2007年 | 37159篇 |
2006年 | 37241篇 |
2005年 | 36025篇 |
2004年 | 34274篇 |
2003年 | 33112篇 |
2002年 | 32436篇 |
2001年 | 66083篇 |
2000年 | 67963篇 |
1999年 | 57275篇 |
1998年 | 14730篇 |
1997年 | 13039篇 |
1996年 | 12554篇 |
1995年 | 11571篇 |
1994年 | 10926篇 |
1993年 | 10097篇 |
1992年 | 42452篇 |
1991年 | 40199篇 |
1990年 | 39035篇 |
1989年 | 37843篇 |
1988年 | 34787篇 |
1987年 | 33914篇 |
1986年 | 32195篇 |
1985年 | 30427篇 |
1984年 | 22024篇 |
1983年 | 18521篇 |
1982年 | 10515篇 |
1979年 | 19611篇 |
1978年 | 13264篇 |
1977年 | 11363篇 |
1976年 | 10205篇 |
1975年 | 11399篇 |
1974年 | 13524篇 |
1973年 | 12841篇 |
1972年 | 12268篇 |
1971年 | 11515篇 |
1970年 | 10925篇 |
1969年 | 10396篇 |
1968年 | 9784篇 |
排序方式: 共有10000条查询结果,搜索用时 230 毫秒
991.
A comparison of 121 mature-age and 270 normal-age entrants who graduated from the University of Queensland Medical School between 1972 and 1987 shows that mature-age entrants are some 7 years older, are more likely to come from public (state) schools and less likely to have parents in professional/technical occupations. Otherwise, the two groups were similar in terms of gender, marital status, number of children, ethnic background and current practice location. The educational background of mature-age entrants prior to admission includes 44.6% with degrees in health-science areas and 31.4% with degrees in non-health areas. Reasons for delayed entry of mature-age entrants include late consideration of medicine as a career (34.7%), financial problems (31.4%), dissatisfaction with previous career (30.6%), poor academic results (19.8%), or a combination of the above factors. Motivations to study medicine include family influences (more so in normal-age entrants), altruistic reasons (more so in mature-age entrants) and a variety of personal/social factors such as intellectual satisfaction, prestige and financial security (similar for both groups) and parental expectations (more so in normal-age entrants). Mature-age entrants experienced greater stress throughout the medical course, especially with regard to financial difficulties, loneliness/isolation from the students and family problems (a greater proportion were married with children). While whole-course grades were similar in both groups, normal-age entrants tended to win more undergraduate honours/prizes and postgraduate diplomas/degrees, including specialist qualifications. Practice settings were similar in terms of group private practice, hospital/clinic practice or medical administration, but there was a greater proportion of mature-age entrants in solo private practice, and a smaller proportion in teaching/research. If given the time over, some two-thirds of both groups would choose medicine as a career. Reasons for job satisfaction include helping patients, intellectual stimulation and financial rewards. Reasons for dissatisfaction include pressure of work, red-tape/paperwork, 'doctor-bashing', long working hours, emotional strain, financial pressure, unfulfilled career expectations and irritation with trivial medical complaints. 相似文献
992.
993.
We report an unusual case of primary cutaneous embryonal rhabdomyosarcoma presenting as a solitary skin lesion on the anterior chest of a 20-month-old child. The tumor was characterized by small, round to oval, poorly differentiated cells. Immunohistochemically, the tumor was negative for NSE, S-100 protein, LCA, and keratin but positive for muscle-specific actin, myoglobin, desmin, and vimentin, thus indicating the presence of myogenous differentiation. Ultrastructural analysis demonstrated thick and thin filaments. Special studies showed no evidence of a primary rhabdomyosarcoma in the patient at a more typical location, nor was there any evidence of metastases. 相似文献
994.
995.
C.T.-guided stereotactic destructive pain procedures; percutaneous cordotomy, trigeminal tractotomy-nucleotomy and extralemniscal myelotomy are presented. All procedures were applied in 32 cases without any mispuncture or complication. Advantages of C.T. guidance are direct visualization of target electrode relations, measurements of spinal cord diameters at the lesion site, and demonstration of spinal cord displacement during the procedure. 相似文献
996.
Fundus biomicroscopy as a clinical technique has been enhanced significantly by the addition of indirect view condensing lenses. The combination of this type of lens with a corneal contact element allows higher power and better stability so that a wider field can be obtained. The Panfunduscope of Schlegel and the Mainster retinal lens are examples of this design that have been successfully applied to both examination and to pan-retinal photocoagulation. Volk has recently introduced a new aspheric design indirect contact lens system which is higher in power and provides a wider field of view (125 degrees) than previously obtainable. This article describes the optical properties and use of the Quadraspheric lens. 相似文献
997.
Motorcycle injuries in Bermuda 总被引:2,自引:0,他引:2
S F Purkiss 《Injury》1990,21(4):228-230
Tourists who hire mopeds or motorcycles for personal use have a risk for accident. The incidence of tourist accidents in Bermuda was 1.57 accidents/1000 tourists evaluated over a 6-month period. The accident incidence increased as the tourist population got larger. Tourists of more than 40 years of age had the greatest increase in incidence for accident during this period. The risk of an injury requiring hospital stay was one patient for every 16,000 tourists visiting the island, and usually involved the fracture of an extremity. All accidents, major or minor, resulted in some form of skin injury. 相似文献
998.
Cellular receptors for matrix proteins in normal human kidney and human mesangial cells 总被引:9,自引:0,他引:9
In the present study we evaluated the distribution of cell adhesion molecules, referred as very late antigens (VLA), in the normal human kidney and in mesangial cells in culture (MC). In addition, we assessed the functional properties of VLA proteins on MC. Normal human kidney and MC were stained by immunoperoxidase with mouse monoclonal antibodies to VLA proteins. We demonstrated that VLA-3, a protein that binds FN, laminin and collagen, is the predominant VLA protein in the human glomerulus and on MC. VLA-3 is located in the mesangium and on the glomerular visceral epithelial cell and endothelial cell surfaces in contact with the glomerular basement membrane. VLA-1 was demonstrated in the glomerular mesangium and VLA-5, an FN specific receptor, was present in the mesangium on glomerular endothelial cells and on MC. VLA-2 and VLA-4 were not present in the normal glomerulus nor on MC. In functional studies we evaluated the binding of MC to FN coated surfaces and the binding and phagocytosis of FN coated fluorescent beads by MC. We showed that MC bind to FN coated surfaces and that the binding is inhibited by anti-FN antibodies, EDTA and peptides containing the amino acid sequence Arg-Gly-Asp (RGD). In addition, anti-VLA-5 but not anti-VLA-3 antibodies inhibited significantly the binding of MC to FN, MC demonstrated binding and phagocytosis of FN coated beads and, purified FN inhibited both phenomena. By affinity chromatography and immunoprecipitation we demonstrated that MC FN binding proteins and MC VLA proteins are composed of two distinct protein chains that have Mr characteristics similar to those of normal human fibroblasts VLA proteins. In conclusion, the glomerular distribution of VLA-3 suggests that this protein is primarily involved on the adhesion of glomerular cells to basement membranes and matrix. MC FN receptors (VLA-5) mediate the binding of MC to FN and could mediate the phagocytosis of FN coated antigen or immune complexes by mesangial cells. 相似文献
999.
The effect of drug concentration and light on the compatibility and stability of cisplatin and fluorouracil in i.v. admixtures was studied. Two sets of admixtures were prepared in 0.9% sodium chloride injection in polyvinyl chloride bags--(1) cisplatin 200 micrograms/mL and fluorouracil 1,000 micrograms/mL and (2) cisplatin 500 micrograms/mL and fluorouracil 10,000 micrograms/mL. Half of the admixtures were protected from light. All admixtures were stored at room temperature (24-26 degrees C), and those admixtures not protected from light were stored under room fluorescent light. After visual inspection, the pH of each admixture was determined, and an aliquot was assayed for drug concentration using a stability-indicating high-performance liquid chromatographic assay. Over a four-hour period, no visual changes were observed and the pH changes observed were negligible. In admixtures containing the lower concentrations of cisplatin and fluorouracil, it took approximately 1.5 hours for the concentration of cisplatin to reach 90% of the initial concentration. By four hours (lower concentration range) and three hours (higher concentration range) after the admixtures were prepared, less than 75% of the initial cisplatin concentration remained. There was less than a 5% decrease measured in the fluorouracil concentrations over the observation time. Admixtures of cisplatin and fluorouracil in 0.9% sodium chloride injection at the concentrations evaluated in this study must be used within one hour of preparation, whether or not they are protected from light. Intravenous administration of fluorouracil and cisplatin by continuous infusion will require alternative approaches to mixing the two drugs in the same container. 相似文献
1000.
F Pithon 《Bulletin des sociétés d'ophtalmologie de France》1990,90(5):561-568
A new approach for the treatment of serious and/or uncurable glaucoma is proposed by the adjonction of a drain, cut in a crinotube, with micro-perforations and set in the classical opening of a trabeculectomy. In four years, for nine cases of particularly severe hypertonia, we observed one relative unsuccess, three real and stable improvements during two years and then with the necessity of local treatment (for rather young patients), and five clear and till today durable improvements. We have also observed a very good local tolerance for all cases, with never a persisting major hypotonia. This simple and efficient process seams susceptible to find its room in the treatment of severe hypertonia. 相似文献