全文获取类型
收费全文 | 82859篇 |
免费 | 8170篇 |
国内免费 | 157篇 |
专业分类
耳鼻咽喉 | 1183篇 |
儿科学 | 2503篇 |
妇产科学 | 1788篇 |
基础医学 | 11841篇 |
口腔科学 | 2006篇 |
临床医学 | 10175篇 |
内科学 | 14597篇 |
皮肤病学 | 1301篇 |
神经病学 | 6730篇 |
特种医学 | 2805篇 |
外国民族医学 | 10篇 |
外科学 | 11423篇 |
综合类 | 1661篇 |
一般理论 | 67篇 |
预防医学 | 9473篇 |
眼科学 | 1852篇 |
药学 | 6751篇 |
1篇 | |
中国医学 | 78篇 |
肿瘤学 | 4941篇 |
出版年
2021年 | 1113篇 |
2020年 | 738篇 |
2019年 | 1119篇 |
2018年 | 1392篇 |
2017年 | 1003篇 |
2016年 | 1093篇 |
2015年 | 1238篇 |
2014年 | 1634篇 |
2013年 | 2566篇 |
2012年 | 3465篇 |
2011年 | 3743篇 |
2010年 | 1981篇 |
2009年 | 1911篇 |
2008年 | 3224篇 |
2007年 | 3540篇 |
2006年 | 3413篇 |
2005年 | 3478篇 |
2004年 | 3249篇 |
2003年 | 3019篇 |
2002年 | 2954篇 |
2001年 | 2716篇 |
2000年 | 2825篇 |
1999年 | 2504篇 |
1998年 | 1075篇 |
1997年 | 885篇 |
1996年 | 869篇 |
1995年 | 787篇 |
1994年 | 815篇 |
1993年 | 745篇 |
1992年 | 2097篇 |
1991年 | 2026篇 |
1990年 | 1898篇 |
1989年 | 1859篇 |
1988年 | 1763篇 |
1987年 | 1781篇 |
1986年 | 1685篇 |
1985年 | 1665篇 |
1984年 | 1389篇 |
1983年 | 1258篇 |
1982年 | 841篇 |
1981年 | 717篇 |
1979年 | 1216篇 |
1978年 | 877篇 |
1977年 | 760篇 |
1976年 | 716篇 |
1975年 | 716篇 |
1974年 | 860篇 |
1973年 | 753篇 |
1972年 | 734篇 |
1971年 | 641篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
A preliminary report of the short-term effect of carbonated beverage consumption on calcium metabolism in normal women 总被引:2,自引:0,他引:2
S Smith J Swain E M Brown G Wyshak T Albright V A Ravnikar I Schiff 《Archives of internal medicine》1989,149(11):2517-2519
A variety of nutritional factors influence the bioavailability of calcium and increase a woman's risk of osteoporosis. Eight healthy women completed an 8-week metabolic study designed to investigate the effect of nonalcoholic carbonated beverage consumption on calcium metabolism. Compared with women receiving a control diet, women consuming a diet high in nonalcoholic carbonated beverages demonstrated similar mean serum levels of calcium, ionized calcium, phosphorus, alkaline phosphatase, parathyroid hormone, 1,25-dihydroxyvitamin D3, and osteocalcin. Twenty-four-hour urine volume, creatinine clearance, calcium-creatinine ratio, and phosphorus-creatinine ratio were similar during consumption of the diet high in nonalcoholic carbonated beverages and the control diet. Twenty-four-hour cyclic adenosine monophosphate-creatinine ratio was significantly lower in women consuming the diet high in nonalcoholic carbonated beverage compared with women receiving the control diet (342 +/- 27.4 nmol/mmol vs 409 +/- 22.1 nmol/mmol). Consumption of a diet high in nonalcoholic carbonated beverages on a short-term basis does not appear to affect adversely the serum or urinary markers of calcium metabolism. 相似文献
22.
E J Garland D H Smith 《Journal of the American Academy of Child and Adolescent Psychiatry》1991,30(4):553-555
Concurrent acute onset of night terrors, somnambulism, and spontaneous daytime panic attacks meeting the criteria for panic disorder is reported in a 10-year-old boy with a family history of panic disorder. Both the parasomnias and the panic disorder were fully responsive to therapeutic doses of imipramine. A second case of night terrors and infrequent full symptom panic attacks is noted in another 10-year-old boy whose mother has panic disorder with agoraphobia. The clinical resemblance and reported differences between night terrors and panic attacks are described. The absence of previous reports of this comorbidity is notable. It is hypothesized that night terror disorder and panic disorder involve a similar constitutional vulnerability to dysregulation of brainstem altering systems. 相似文献
23.
24.
Paul Roderick Ruth Davies Chris Jones Terry Feest Steve Smith Ken Farrington 《Nephrology, dialysis, transplantation》2004,19(3):692-701
BACKGROUND: The demand for renal replacement therapy (RRT) in England has risen steadily, although from a lower base than many other developed countries. Predicting the future demand for RRT and the impact of factors such as the acceptance rate, transplant supply and patient survival, is required in order to inform the planning of such services. METHODS: A discrete event simulation model estimates the future demand for RRT in England in 2010 for a range of scenarios. The model uses current prevalence and current and projected future acceptance rates, survival rates and the transitions between modalities to predict future patient numbers. National population and mortality data, published literature and data from the UK Renal Registry and UK Transplant, are used to estimate unmet need for RRT, the impact of changing demography and incidence of Type 2 diabetes, patient haemodialysis (HD) survival and transplant supply. RESULTS: By 2010 the predicted prevalence will have increased from about 30,000 in 2000 to between 42 and 51,000 (900-1000 p.m.p.), an average annual growth of 4.5-6%. Changing transplant supply has a small effect on overall numbers but changes the proportion of patients with functioning graft by up to 8%. Even with an optimistic increase in transplant supply (11% p.a. for 5 years), numbers on HD will continue to rise substantially, especially in the elderly. The factors most influencing future patient numbers are the acceptance rate and dialysis survival. CONCLUSION: This model predicts a substantial growth in the RRT population to 2010 to a rate approaching 1000 p.m.p., particularly in the elderly and those on HD, with a steady state not being reached for at least 25 years. 相似文献
25.
26.
Angiolymphoid hyperplasia with eosinophilia of the orbit associated with obstructive airway disease 总被引:2,自引:0,他引:2
Two patients with angiolymphoid hyperplasia with eosinophilia isolated to the orbit had eyelid swelling, a superior orbital mass, and histories of intermittent obstructive airway disease. One patient later developed a transient peripheral blood eosinophilia as high as 36%. One lesion recurred 38 months postoperatively and responded to systemic corticosteroid therapy. 相似文献
27.
Repeated administration of the antimanic drug lithium (4 mEq/kg/day for 2, 4 or 6 days, i.p.) to rats produced a progressive decline and eventual depletion of dynorphin-A (1-8) (DYN) concentration whereas Met5-enkephalin (ENK) was only marginally decreased in the neurointermediate lobe of the pituitary (NIL). Administration of a neuroleptic haloperidol neither affected ENK and DYN levels nor influenced lithium-induced changes. The study reveals that lithium produces a preferential perturbation in the dynorphin system relative to the enkephalin system. These results taken together with other evidence, indicate that dynorphin is possibly coreleased with vasopressin following lithium administration and provide a pharmacological support to the previously described colocalization and corelease of these endogenous peptides in the NIL. 相似文献
28.
The ameloblastoma is a tumor arising predominantly in the mandible from odontogenic epithelium, and is locally invasive. It is rarely malignant; but even when benign, it causes gross local destruction and expansion of tissue. Growth is persistent, and recurrence may occur more than a decade after presumed total resection. Surgical resection should include a reasonable margin of healthy tissue whenever possible. Late patient presentation due to a paucity of symptoms, and insiduous tumor growth patterns render complete removal of the ameloblastoma difficult. Follow-up examinations should span a prolonged period, exceeding 10-15 years. 相似文献
29.
Unemployment is over three million in Britain, and unemployment is known to be associated with poor health. It has been suggested that health authorities should produce a comprehensive response to the health problems caused by unemployment, and a survey was undertaken to find how many had done so. All the regional and district health authorities in England, the health boards of Wales, Scotland, and Northern Ireland, and the family practitioner committees of England and Wales were asked by letter what they were doing to respond to the health problems of unemployment. A list of suggestions of what they might be doing was enclosed. The overall response rate was 77% (255/331), and 50% (127/255) of the respondents were doing something--33.3% (3/9) of the regional health authorities, 64% (101/158) of the district health authorities and health boards, and 26% (23/88) of the family practitioner committees. The paper describes what they were doing. A relation was sought between the level of unemployment in an area and the extent of the response, and a significant association was found. Half of Britain's health authorities are now responding in some way to the health problems associated with unemployment. 相似文献
30.
Claire-Jehanne Dubouloz Diane Laporte Martha Hall Brenda Ashe C Douglas Smith 《The American journal of occupational therapy》2004,58(4):398-407
The purpose of this qualitative study was to examine the process of transformation of personal beliefs, values, feelings, and knowledge (meaning perspectives) underlying occupational change in a small group of clients with rheumatoid arthritis during home-based rehabilitation. A grounded theory approach used to collect and analyze data concurrently included: (1) a sample of five adult clients diagnosed with rheumatoid arthritis in occupational therapy, (2) data collection through 28 semi-directed interviews, and (3) data analysis using the constant comparison method. The study identified meaning perspectives of these clients with rheumatoid arthritis and explored the transformation of perspectives related to the modification of occupational performance. The study suggests that the exploration of meaning perspective transformation by clients and therapists could be a potential part of rehabilitation intervention. 相似文献