全文获取类型
收费全文 | 32516篇 |
免费 | 1697篇 |
国内免费 | 73篇 |
专业分类
耳鼻咽喉 | 428篇 |
儿科学 | 1258篇 |
妇产科学 | 592篇 |
基础医学 | 4030篇 |
口腔科学 | 640篇 |
临床医学 | 2196篇 |
内科学 | 8456篇 |
皮肤病学 | 982篇 |
神经病学 | 2906篇 |
特种医学 | 911篇 |
外科学 | 4991篇 |
综合类 | 150篇 |
一般理论 | 6篇 |
预防医学 | 2717篇 |
眼科学 | 614篇 |
药学 | 1718篇 |
中国医学 | 109篇 |
肿瘤学 | 1582篇 |
出版年
2023年 | 187篇 |
2022年 | 133篇 |
2021年 | 745篇 |
2020年 | 347篇 |
2019年 | 808篇 |
2018年 | 1209篇 |
2017年 | 698篇 |
2016年 | 676篇 |
2015年 | 707篇 |
2014年 | 846篇 |
2013年 | 1332篇 |
2012年 | 2176篇 |
2011年 | 2375篇 |
2010年 | 1241篇 |
2009年 | 967篇 |
2008年 | 1944篇 |
2007年 | 2077篇 |
2006年 | 1988篇 |
2005年 | 1965篇 |
2004年 | 1861篇 |
2003年 | 1665篇 |
2002年 | 1644篇 |
2001年 | 1053篇 |
2000年 | 1276篇 |
1999年 | 920篇 |
1998年 | 173篇 |
1997年 | 116篇 |
1996年 | 121篇 |
1995年 | 78篇 |
1994年 | 71篇 |
1993年 | 65篇 |
1992年 | 338篇 |
1991年 | 260篇 |
1990年 | 267篇 |
1989年 | 186篇 |
1988年 | 142篇 |
1987年 | 133篇 |
1986年 | 140篇 |
1985年 | 111篇 |
1984年 | 97篇 |
1983年 | 70篇 |
1982年 | 50篇 |
1981年 | 46篇 |
1979年 | 42篇 |
1974年 | 69篇 |
1973年 | 66篇 |
1972年 | 45篇 |
1971年 | 46篇 |
1970年 | 45篇 |
1969年 | 48篇 |
排序方式: 共有10000条查询结果,搜索用时 500 毫秒
81.
Steven R. Alexander Gerald S. Arbus Khalid M. H. Butt Susan Conley Richard N. Fine Ira Greifer Alan B. Gruskin William E. Harmon Paul T. McEnery Thomas E. Nevins Nadia Nogueira Oscar Salvatierra Jr Amir Tejani 《Pediatric nephrology (Berlin, Germany)》1990,4(5):542-553
This report of the North American Pediatric Transplant Cooperative Study summarizes data contributed by 57 participating centers on 754 children with 761 transplants from 1 January 1989 to 16 February 1989. Data collection was initiated in October 1987 and follow-up of all patients is ongoing. Transplant frequency increased with age; 24% of the patients were less than 5 years, with 7% being under 2 years. Common frequent diagnoses were: aplastic/dysplastic kidneys (18%), obstructive uropathy (16%), and focal segmental glomerulosclerosis (12%). Preemptive transplant, i.e., transplantation without prior maintenance dialysis, was performed in 21% of the patients. Dialytic modalities pretransplant were peritoneal dialysis in 42% and hemodialysis in 25%. Bilateral nephrectomy was reported in 29%. Live-donor sources accounted for 42% of the transplants. Among cadaveric donors, 41% of the donors were under 11 years old. During the first post-transplant month, maintenance therapy was used similarly for live-donor and cadaver source transplants, with prednisone, cyclosporine, and azathioprine used in 93%, 83%, and 81%, respectively. Triple therapy with prednisone, cyclosporine, and azathioprine was used in 78%, 75%, and 75% of functioning cadaver source transplants at 6 months, 12 months, and 18 months as opposed to 60%, 63%, and 54% for live-donor procedures, with single-drug therapy being uncommon. Rehospitalization during months 1–5 occurred in 62% of the patients, with treatment of rejection and infection being the main causes. Additionally, 9% were hospitalized for hypertension. During months 6–12 and 12–17, 30% and 28% of the patients with functioning grafts were rehospitalized. Times to first rejection differed significantly for cadaver and live-donor transplants. The median time to the first rejection was 36 days for cadaver transplants and 156 days for live-donor transplants. Overall, 57% of treated rejections were completely reversible although the complete reversal rate decreased to 37% for four or more rejections. One hundred and fifty-two graft failures had occurred at the time of writing, with a 1-year graft survival estimate of 0.88 for live-donor and 0.71 for cadaver source transplants. In addition to donor source, recipient age is a significant prognostic factor for graft survival. Among cadaver donors, decreasing donor age is associated with a decreasing probability of graft survival. Thirty-five deaths have occurred; 16 attributed to infection and 19 to other causes. The current 1-year survival estimate is 0.94. There have been 9 malignancies.A list of all participating centers and the names of the investigators is printed on pages 552–553 相似文献
82.
Oscar A. Alvarez M.D. Judith A. Maples M.D. Fermin O. Tio M.D. Makau Lee M.D. Ph.D. 《The American journal of gastroenterology》1995,90(8):1350-1351
Cokeromyces recurvatus , a sporangiola-forming dimorphic is a rare cause of urogenital infection in humans. We report here a case of severe watery diarrhea due lo C. recurvains , which was treated successfully with high-dose oral nystatin therapy. We speculate that our patient was probably predisposed to infections due to opportunistic organisms, such as C. recurvatus , because of post-transplantation immunosuppression. To our knowledge, our patient represents the first documented case of diarrhea due to C. recurvatus in man und this ease highlights the potential pathogenic capability of this opportunistic organism in immunosuppressed patients. 相似文献
83.
84.
缺血性卒中或短暂性脑缺血发作患者的卒中预防指南 总被引:8,自引:0,他引:8
Ralph L.Sacco Robert Adams Grge Albers Mark J.ALBERTS Oscar Benavente Karen Furie Larry B.Goldstein Philip Gorelick Jonathan Halperin Robert Harbaugh S.Claiborne Johnston Irene Katzan Margaret Kelly-Hayes Edgar J.Kenton Michael Marks Lee H.Schwamm Thomas Tomsick 曹勇军 《中华脑血管病论坛》2006,4(1):21-66
这份新声明旨在为缺血性卒中或短暂性脑缺血发作存活者的缺血性卒中预防提供全面和及时的循证推荐,循证推荐包括对危险因素的控制,动脉粥样硬化性疾病的干预措施,心源性栓塞的抗栓治疗以及非心源性卒中抗血小板药的应用。另外,还为其他多种特殊情况下复发性卒中的预防提供了推荐、包括动脉夹层分离、卵圆孔未闭、高同型半胱氨酸血症、高凝状态、镰状细胞病、脑静脉窦血栓形成、女性卒中(特别是与妊娠和绝经后激素替代治疗相关卒中),脑出血后肮凝药的应用,以及该指南在高危人群中执行和应用的特殊措施。 相似文献
85.
C Delgado Ramis R Martín Durán J A Vázquez de Prada F G Vílchez M J Zarauza J Zueco J Ruano J J Olalla 《Revista espa?ola de cardiología》1992,45(4):284-287
Blood flow pattern recording of hepatic veins using pulsed Doppler technique is a valid method for the assessment of hemodynamic changes in right atrium. We describe a patient with severe aortic regurgitation secondary to acute infective endocarditis who underwent surgical repair. Before surgery and during the postoperative period, several evolutive studies (including conventional echo and hepatic veins pulsed Doppler recordings) were performed. The different central blood flow patterns were correlated with changing hemodynamic conditions during follow-up of the patient. These central flow velocities reflect changes in right atrial pressure contours, and are easily obtained non-invasively with pulsed wave Doppler ultrasound of the hepatic veins. They could be an useful method for assessing right heart filling dynamics, reporting characteristic patterns in other cardiac disease states. 相似文献
86.
F. Deulofeu J. M. Nava F. Bella C. Martí M. A. Morera B. Font D. Fontanals J. Lite J. Garau A. Calderón M. T. Coll S. Uriz V. Pineda 《European journal of clinical microbiology & infectious diseases》1994,13(8):633-638
The incidence and characteristics of invasiveHaemophilus influenzae disease were studied in 43 adult patients admitted to the acute care hospitals in El Vallés County (Barcelona, Spain) between January 1987 and June 1992. The annual incidence ofHaemophilus influenzae disease was 1.2 per 100,000 inhabitants. Pneumonia occurred in 24 patients, meningitis in five, intraabdominal infections in three, obstetric infections in two, epiglottitis in two and cellulitis in one. In six patients the source of infection was unknown. Ten (23 %) of the infections were hospital acquired. Underlying conditions were diagnosed in 30 (70 %) patients. NontypeableHaemophilus influenzae strains predominated in all adult age groups. Sixty-one percent of type b and 34 % of nontypeable strains were ampicillin resistant (p=0.08). Multiple antibiotic resistance was also high among type b (53 %) and nontypeable (18 %) strains. The mortality rate was significantly higher in patients with pneumonia, bactaeremia from an unidentified focus or shock at presentation. 相似文献
87.
C Castelo-Branco M J Martínez de Osaba F Pons J González-Merlo 《European journal of obstetrics, gynecology, and reproductive biology》1992,44(2):131-136
Eighty-four postmenopausal women who were randomly allocated to one of four groups, completed a 1 year follow-up. The first group (n = 20) received 0.625 mg/day conjugated estrogens cyclically (CE; 25 days/month). The second (n = 23) received 0.625 mg/day of CE continuously, and the third (n = 17) received 50 micrograms/day of transdermal 17 beta-estradiol cyclically (24 days/month). All these groups also received 2.5 mg of medroxiprogesterone acetate sequentially for the last 12 days of hormone replacement therapy, while the fourth group (n = 24) constituted a treatment-free control group. Dual photon absorptiometry was carried out before therapy and was repeated after 1 year. Serum calcium, phosphate and osteocalcine levels, and the urinary calcium/creatinine and hydroxyproline/creatinine ratios, were measured prior to treatment and 6 and 12 months thereafter. All treatment groups showed an increase in bone mineral content. This increase was higher in the continuous CE treatment group (4.4%, P less than 0.05) and in transdermal group (7.1%, P less than 0.01). Concomitant biochemical effects at 6 and 12 months, reduction in urine calcium and hydroxyproline, reduction in blood calcium, phosphate and osteocalcine, were compatible with the observed effects on bone mineral. 相似文献
88.
J L Pérez Arellano N M Barrios González T Martín Domínguez M L Sánchez Benítez de Soto A Jiménez López 《Journal of investigational allergology & clinical immunology》1992,2(4):219-228
Experimental models of hypersensitivity pneumonitis are important tools for the study of the pathogenesis of this disease. In this paper we review the characteristics of the main animal models developed until now. The HP models in rats seem to be particularly appropriate for studying pigeon fancier's disease and the HP induced by chemicals, as well as for studying mediators of acute lesions induced by immunocomplexes. However, the HP models developed in rats are of less value in the evaluation of other aspects of the pathogenesis of this clinical entity in humans. The murine models of HP offer several advantages: the ease and simplicity of intranasal administration, the ability to produce acute and subacute pulmonary lesions similar to those found in humans, the possibility of reproducing lesions similar to those of nonaffected exposed subjects and the possibility of pharmacologically modulating the process. Their disadvantages lie in the different pulmonary lymphocyte response and the difficulty in reproducing a model of chronic fibrosis. The HP models in rabbits are extraordinarily useful for evaluating the immunological mechanisms through which subjects repeatedly exposed to the antigen do not develop clinical manifestations. However, the rabbit has several immunological differences when compared to humans, and the effect of some immunomodulators in this animal is different. The models of HP in guinea-pigs have as advantages the ease in handling the animals, the possibility of pharmacological manipulation, and the ability to induce an acute phase that is very similar to that observed in humans. The drawback, however, is the low lymphocyte response and the striking eosinophilic reaction that contrast with the bronchoalveolar data found in HP in humans. In conclusion, there is no ideal model to reproduce all the findings observed in humans, suggesting that the experimental animal and the method of developing HP should be selected on the basis of concrete research aims. 相似文献
89.
R Ruiz-Beltrán J I Herrero-Herrero A M Martín-Sanchez L A Criado-Gutiérrez 《European journal of epidemiology》1992,8(1):136-139
In an endemic zone for Mediterranean spotted fever levels of antibodies to R. conorii were evaluated in serum samples from wild rabbits (Orytolagus cuniculus) and hares (Lepus granatensis) using an indirect microimmunofluorescence antibody test. The results of the study show that the wild rabbit may carry out in this area an important function in the maintenance of R. conorii in nature. 相似文献
90.
Sara Jo Nixon Austin L. Errico Oscar A. Parsons William R. Leber Cynthia J. Kelley 《Alcoholism, clinical and experimental research》1992,16(5):949-954
This study was conducted to determine whether alcoholic and control subjects respond differently to manipulations that either enhance personal involvement (PI) or reduce negative affect (R, relaxation) on tests of neuropsychological function. In Phase 1, 48 male alcoholics and 36 male control subjects completed neuropsychological tasks under standard instructional sets. In Phase 2, subjects completed equivalent forms of these tests under one of three randomly assigned conditions; the PI condition in which subjects were encouraged to identify specific ways of improving their performance, the R condition in which subjects participated in a short relaxation exercise designed to reduce anxiety, or a No Treatment (NT) condition in which no attempt to manipulate the subjects' involvement or affect was made. Alcoholics were inferior to controls in both Phase 1 and Phase 2 [Fs (1,82) > 5.03, ps < 0.03]. The experimental manipulation differentially affected measures of negative affect and effort in the predicted direction. There were no group x condition interactions. Alcoholic and control subjects responded comparably to the experimental manipulations. This investigation, in combination with others using related manipulations, reinforces the hypothesis that alcohol-related cognitives dysfunction reflects an underlying deficit in brain states. 相似文献