全文获取类型
收费全文 | 32946篇 |
免费 | 1846篇 |
国内免费 | 94篇 |
专业分类
耳鼻咽喉 | 413篇 |
儿科学 | 1084篇 |
妇产科学 | 667篇 |
基础医学 | 4469篇 |
口腔科学 | 1215篇 |
临床医学 | 2935篇 |
内科学 | 7384篇 |
皮肤病学 | 918篇 |
神经病学 | 2634篇 |
特种医学 | 661篇 |
外国民族医学 | 1篇 |
外科学 | 4072篇 |
综合类 | 220篇 |
一般理论 | 14篇 |
预防医学 | 3667篇 |
眼科学 | 622篇 |
药学 | 2003篇 |
中国医学 | 166篇 |
肿瘤学 | 1741篇 |
出版年
2024年 | 26篇 |
2023年 | 257篇 |
2022年 | 398篇 |
2021年 | 1064篇 |
2020年 | 555篇 |
2019年 | 999篇 |
2018年 | 1335篇 |
2017年 | 831篇 |
2016年 | 752篇 |
2015年 | 926篇 |
2014年 | 1093篇 |
2013年 | 1508篇 |
2012年 | 2453篇 |
2011年 | 2764篇 |
2010年 | 1338篇 |
2009年 | 1093篇 |
2008年 | 2145篇 |
2007年 | 2168篇 |
2006年 | 2072篇 |
2005年 | 2027篇 |
2004年 | 1685篇 |
2003年 | 1649篇 |
2002年 | 1498篇 |
2001年 | 730篇 |
2000年 | 741篇 |
1999年 | 562篇 |
1998年 | 210篇 |
1997年 | 125篇 |
1996年 | 111篇 |
1995年 | 99篇 |
1994年 | 84篇 |
1993年 | 69篇 |
1992年 | 187篇 |
1991年 | 196篇 |
1990年 | 138篇 |
1989年 | 112篇 |
1988年 | 96篇 |
1987年 | 90篇 |
1986年 | 88篇 |
1985年 | 85篇 |
1984年 | 66篇 |
1983年 | 49篇 |
1982年 | 30篇 |
1981年 | 31篇 |
1980年 | 28篇 |
1979年 | 43篇 |
1978年 | 24篇 |
1977年 | 29篇 |
1974年 | 22篇 |
1973年 | 28篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
Antonio C Pastorino Rejane D C Rimazza Cláudio Leone Ana Paula M Castro Dirceu Solé Cristina M A Jacob 《The Journal of asthma》2006,43(9):695-700
BACKGROUND: Identify risk factors for asthma in adolescents from S?o Paulo, Brazil. METHODS: total of 528 adolescents (141 asthmatics, 387 control subjects) from the ISAAC study (phase III) were submitted to a complementary questionnaire to evaluate risk factors, through response to questions regarding personal history, environment, and diet and an agreement to undergo the skin prick test (SPT) for aeroallergens. RESULTS: Positive SPT to at least one allergen occurred in 49.4% adolescents. The risk factors for asthma were: prematurity (OR: 3.84, 95% CI: 1.54-9.64), rhinitis (OR: 3.18, 95% CI: 1.71-5.91), positivity in the SPT (OR: 2.81, 95% CI: 1.48-5.32), eczema in characteristic skin-folds (OR: 2.86, 95% CI: 1.13-7.26), and an allergic mother (OR: 2.01, 95% CI: 1.02-3.93). The consumption of cooked vegetables was a protective factor for asthma (OR: 0.37, 95% CI: 0.18-0.79) CONCLUSIONS: Asthma is a multifatorial disease. An allergic mother, aeroallergen sensitization, rhinitis, eczema and prematurity were considered risk factors and the consumption of cooked vegetables was considered a protective factor for asthma in this population. 相似文献
83.
84.
O S Giordano M J Pestchanker E Guerreiro J R Saad R D Enriz A M Rodríguez E A Jáuregui J Guzmán A O María G H Wendel 《Journal of medicinal chemistry》1992,35(13):2452-2458
The structural requirements for the gastric cytoprotective activity of several sesquiterpene lactones are reported. A theoretical-experimental study on the potentially active centers is carried out. The biological evaluation of reduced analogues and the simulation of the molecular interactions between these compounds and an endogenous cysteine residue suggest that the presence of a non sterically hindered Michael acceptor seems to be an essential structural requirement for the cytoprotective activity in this family of compounds. This observation suggests that cytoprotection is mediated through a Michael reaction between the sulfhydryl-containing peptides of the mucosa and Michael acceptors present in the molecules under study. This mechanism of action is in addition to and distinct from the one proposed in our previous paper, namely, that these sesquiterpenes stimulate endogenous synthesis of prostaglandins. 相似文献
85.
Paula Jablonski Kirsty Baxter Brian O. Howden Anita C. Thomas Vernon C. Marshall Alicia Stein-Oakley Napier M. Thomson 《ANZ journal of surgery》1995,65(2):114-119
A reproducible animal model is essential for the study of the pathogenesis of chronic rejection. This study investigates: (i) the optimal pre-transplant blood transfusion conditions to induce tolerance in a strongly rejecting rat kidney allograft model (Dark Agouti to Albino-Surgery) and avoiding post-transplant immunosuppression; (ii) the functional and histological changes that occur in long-term surviving kidneys and their similarity to chronic rejection; and (iii) the maintenance of tolerance. Prolonged survival occurred after administration of at least two donor blood transfusions with concomitant cyclosporin A (5 mg/kg per day). The time-span between transfusions appeared to be critical: 4 days was more effective than 2 or 7 days. Ineffective treatment led to death within the first 2 weeks post-transplant with histological evidence of acute graft rejection. Seventy-five per cent of long-term survivors experienced impaired renal function in the first week which improved spontaneously and remained stable in 93% of the surviving animals after 100 days and in 668 after 200 days. The morphology of long-term allografts was extremely variable from minor to extensive tubular atrophy, interstitial fibrosis, glomerular hypertrophy, focal and segmental glomerulosclerosis and vascular changes. Glomerular hypertrophy occurred in uninephrectomized controls and probably denoted a response to uninephrectomy. Glomerulosclerosis increased with time and was absent in controls. Although chronic damage was evident, the rats remained tolerant to fresh donor skin. Replacement of the original kidney allograft with a fresh donor kidney resulted in 70% survival. These second grafts showed less severe renal dysfunction and morphological damage than the original allografts in the long-term follow up. 相似文献
86.
87.
F Calero J Jimeno F Rodríguez-Escudero J Asins Codoner J Mendana J Iglesias F Murillo F Ugalde A Armas A Rementería 《European journal of gynaecological oncology》1992,13(1):83-89
We have evaluated the clinical toxicity of Epirubicin 80 mg/m2 i.v., every 3 weeks in 58 patients with FIGO III-IV endometrial adenocarcinoma or squamous uterine cervix carcinoma. The median age of the whole group was 59 years (37-77); 37 patients were previously treated with radiotherapy and two with cisplatin based chemotherapy. The median KI at entry was 80. A total of 308 courses of chemotherapy were administered with a median of 5 per patient. Overall toxicity data shows that this dose level is associated with mild haematological toxicity with only two cases having grade 3 (WHO) leukopenia. Nine patients suffered emesis in spite of prophylactic therapy and were classified as grade 3. One case presented grade four diarrhoea but the relation with the antineoplastic treatment was uncertain. One woman with hepatic dysfunction at entry had grade 3 leukopenia, developed pneumonia and died. The median total cumulative dose of EPI was 360 mg/m2 (160-880) with 19 cases exposed to cumulative doses higher than 550 mg/m2. Congestive heart failure was not observed. Our data confirm the safety of EPI at these dose levels and suggest the possibility of developing new trials with higher doses of this anthracycline analog. 相似文献
88.
89.
Eduardo Domínguez-Adame Lanuza Encarnación Jiménez Andrade Antonio Rodríguez Fernández Jaime Medina Díez 《Clinical & translational oncology》2005,7(2):78-80
Primary linitis plastica of the rectum is an infrequent and unusual rectal carcinoma. We report a new case that presented clinically as a haemorrhoidal syndrome. We comment on the characteristics--clinical picture and histopathology--of this uncommon presentation of rectal tumour, as well as its clinical history and prognosis taking into account that the literature consulted indicated the unusualness of primary linitis plastica of the rectum. 相似文献
90.
In vivo MRI of cancer cell fate at the single-cell level in a mouse model of breast cancer metastasis to the brain. 总被引:7,自引:0,他引:7
Chris Heyn John A Ronald Soha S Ramadan Jonatan A Snir Andrea M Barry Lisa T MacKenzie David J Mikulis Diane Palmieri Julie L Bronder Patricia S Steeg Toshiyuki Yoneda Ian C MacDonald Ann F Chambers Brian K Rutt Paula J Foster 《Magnetic resonance in medicine》2006,56(5):1001-1010
Metastasis (the spread of cancer from a primary tumor to secondary organs) is responsible for most cancer deaths. The ability to follow the fate of a population of tumor cells over time in an experimental animal would provide a powerful new way to monitor the metastatic process. Here we describe a magnetic resonance imaging (MRI) technique that permits the tracking of breast cancer cells in a mouse model of brain metastasis at the single-cell level. Cancer cells that were injected into the left ventricle of the mouse heart and then delivered to the brain were detectable on MR images. This allowed the visualization of the initial delivery and distribution of cells, as well as the growth of tumors from a subset of these cells within the whole intact brain volume. The ability to follow the metastatic process from the single-cell stage through metastatic growth, and to quantify and monitor the presence of solitary undivided cells will facilitate progress in understanding the mechanisms of brain metastasis and tumor dormancy, and the development of therapeutics to treat this disease. 相似文献