全文获取类型
收费全文 | 3986篇 |
免费 | 306篇 |
国内免费 | 59篇 |
专业分类
耳鼻咽喉 | 22篇 |
儿科学 | 193篇 |
妇产科学 | 74篇 |
基础医学 | 386篇 |
口腔科学 | 84篇 |
临床医学 | 528篇 |
内科学 | 897篇 |
皮肤病学 | 42篇 |
神经病学 | 233篇 |
特种医学 | 356篇 |
外科学 | 601篇 |
综合类 | 88篇 |
预防医学 | 356篇 |
眼科学 | 44篇 |
药学 | 260篇 |
中国医学 | 4篇 |
肿瘤学 | 183篇 |
出版年
2022年 | 21篇 |
2021年 | 64篇 |
2020年 | 29篇 |
2019年 | 47篇 |
2018年 | 65篇 |
2017年 | 43篇 |
2016年 | 26篇 |
2015年 | 58篇 |
2014年 | 63篇 |
2013年 | 111篇 |
2012年 | 141篇 |
2011年 | 145篇 |
2010年 | 120篇 |
2009年 | 82篇 |
2008年 | 172篇 |
2007年 | 204篇 |
2006年 | 166篇 |
2005年 | 157篇 |
2004年 | 182篇 |
2003年 | 165篇 |
2002年 | 146篇 |
2001年 | 155篇 |
2000年 | 139篇 |
1999年 | 99篇 |
1998年 | 87篇 |
1997年 | 69篇 |
1996年 | 90篇 |
1995年 | 70篇 |
1994年 | 67篇 |
1993年 | 69篇 |
1992年 | 80篇 |
1991年 | 71篇 |
1990年 | 82篇 |
1989年 | 93篇 |
1988年 | 87篇 |
1987年 | 95篇 |
1986年 | 81篇 |
1985年 | 83篇 |
1984年 | 63篇 |
1983年 | 49篇 |
1982年 | 44篇 |
1981年 | 45篇 |
1980年 | 36篇 |
1979年 | 54篇 |
1978年 | 46篇 |
1977年 | 35篇 |
1976年 | 24篇 |
1975年 | 32篇 |
1974年 | 36篇 |
1973年 | 28篇 |
排序方式: 共有4351条查询结果,搜索用时 0 毫秒
11.
J J Amato M L Marbey C Bush R J Galdieri J V Cotroneo J Bushong 《The Journal of thoracic and cardiovascular surgery》1988,95(1):62-69
The concept of central shunting in smaller children with the Waterston shunt was initially well accepted. It has been abandoned because of the difficult estimation of lumen size, preferential flow to the right side, and difficulty in the take-down of the shunt. We have replaced the Waterston shunt with a short segment of polytetrafluoroethylene between the ascending aorta and the main pulmonary artery. From January 1979 to December 1986, 190 shunt operations were performed in 157 patients, with the use of 26 classic Blalock-Taussig shunts (13.7%), six Waterston shunts (3.1%), nine Glenn shunts (4.7%), 80 central aortopulmonary polytetrafluoroethylene shunts (42.2%), and 69 modified Blalock-Taussig shunts (36.3%). Polytetrafluoroethylene grafts were used for 149 of the 190 (78.4%) shunts. Overall mortality was 15.2%, with nine early deaths (4.7%) and 20 late deaths (10.5%). Deaths were due to the complex nature of the congenital anomaly or definitive surgical repair. The patients weighed from 1.6 to 48 kg and ages ranged from 1 day to 22 years. We have modified our technique so that (1) graft length is less than 0.5 cm and both ends are beveled, (2) the aortotomy is fashioned with a punch, (3) the center of the polytetrafluoroethylene graft is never clamped, (4) heparin is given during the construction of the shunt, and (5) aspirin (10 mg/kg/day) is administered daily. Patency ranges from 1 to 4 years. We conclude that the polytetrafluoroethylene shunt provides excellent palliation and that the central shunt, in the smaller child and infant, offers the benefits of shunting without distortion of the peripheral pulmonary arteries. 相似文献
12.
13.
A W Fyles A J Dembo R S Bush W Levin L A Manchul J F Pringle G A Rawlings J F Sturgeon G M Thomas J Simm 《International journal of radiation oncology, biology, physics》1992,22(5):847-851
Between 1971 and 1985, 598 patients with ovarian carcinoma were treated with abdomino-pelvic radiation therapy. Acute complications included nausea and vomiting in 364 patients (61%) which were severe in 36, and diarrhea in 407 patients (68%), severe in 35. Leukopenia (less than 2.0 x 10(9) cells/liter) and thrombocytopenia (less than 100 x 10(9) cells/liter) occurred in 64 patients (11%) each. Treatment interruptions occurred in 136 patients (23%), and 62 patients (10%) did not complete treatment. In both situations the most common cause was myelosuppression. Late complications included chronic diarrhea in 85 patients (14%), transient hepatic enzyme elevation in 224 (44%), and symptomatic basal pneumonitis in 23 (4%). Serious late bowel complications were infrequent: 25 patients (4.2%) developed bowel obstruction and 16 required operation. Multivariate analysis was unable to determine any significant prognostic factors for bowel obstruction; however, the moving-strip technique of radiation therapy was associated with a significantly greater risk of developing chronic diarrhea, pneumonitis, and hepatic enzyme elevation than was the open beam technique. We conclude that abdomino-pelvic radiation therapy as used in these patients is associated with modest acute complications and a low risk of serious late toxicity. 相似文献
14.
The protein and allergen contents of four commercial soybean skin test extracts were tested by SDS-PAGE and immunoblotting using sera from soy-allergic adults. Polyacrylamide gels stained with Coomassie Blue showed an absence of several major soybean proteins, particularly those at higher molecular weights. The acidic subunits of glycinin and beta-conglycinin, major soybean storage proteins, appear to be absent or present in much reduced amounts. Immunoblots with soy-allergic sera indicate alteration, reduction, or loss of IgE-binding in the commercial extracts as compared to extracts of soy flour. In one soy-allergic patient, skin tests revealed a negative response to three of the commercial soybean extracts and a mild response to one extract. Defatted soy flour obtained from two of the four extract manufacturers was extracted in the laboratory using a standard procedure for the isolation of soybean proteins. In one case, the extract still had an abnormal protein profile on gel electrophoresis while in the other case, the new extraction procedure gave significantly improved extraction of soy protein. Preparation methods appear to be partially responsible for the variable allergen content in commercial soybean skin test extracts. 相似文献
15.
Acute selective serotonin reuptake inhibitors increase conditioned fear expression: blockade with a 5-HT(2C) receptor antagonist. 总被引:3,自引:0,他引:3
Nesha S Burghardt David E A Bush Bruce S McEwen Joseph E LeDoux 《Neuropsychopharmacology》2007,62(10):1111-1118
BACKGROUND: Selective serotonin reuptake inhibitors (SSRIs) effectively treat various anxiety disorders, although symptoms of anxiety are often exacerbated during early stages of treatment. We previously reported that acute treatment with the SSRI citalopram enhances the acquisition of auditory fear conditioning, which is consistent with the initial anxiogenic effects reported clinically. Here, we extend our findings by assessing the effects of acute SSRI treatment on the expression of previously acquired conditioned fear. METHODS: Rats underwent fear conditioning drug-free. Tone-evoked fear responses were tested after drug treatment the following day. This protocol more closely resembles the clinical setting than pre-conditioning treatment, because it evaluates effects of treatment on a pre-existing fear rather than on the formation of a new fear memory. RESULTS: A single pre-testing injection of the SSRIs citalopram or fluoxetine significantly increased fear expression. There was no effect of the antidepressant tianeptine or the norepinephrine reuptake inhibitor tomoxetine, indicating that this effect is specific to SSRIs. The SSRI-induced enhancement in fear expression was not blocked by tropisetron, a 5-HT(3) receptor antagonist, but was blocked by SB 242084, a specific 5-HT(2C) receptor antagonist. CONCLUSIONS: Enhanced activation of 5-HT(2C) receptors might be a mechanism for the anxiogenic effects of SSRIs observed initially during treatment. 相似文献
16.
17.
Macrolides is effective therapy in patients with cystic fibrosis (CF). We describe a girl with CF given long-term azithromycin who died of rapidly progressive lung disease. She was found to have rising titers of mycoplasma serology, suggesting a possible causative role of a resistant mycoplasma infection. Mycoplasma infection should be considered in CF patients who are deteriorating, even if they are being treated with macrolides, to which these organisms are usually susceptible. 相似文献
18.
19.
20.
Ludman E Katon W Bush T Rutter C Lin E Simon G Von Korff M Walker E 《Psychological medicine》2003,33(6):1061-1070
BACKGROUND: A randomized trial of a primary care-based intervention to prevent depression relapse resulted in improved adherence to long-term antidepressant medication and depression outcomes. We evaluated the effects of this intervention on behavioural processes and identified process predictors of improved depressive symptoms. METHOD: Patients at high risk for depression recurrence or relapse following successful acute phase treatment (N=386) were randomly assigned to receive a low intensity 12-month intervention or continued usual care. The intervention combined education about depression, shared decision-making regarding use of maintenance pharmacotherapy and cognitive-behavioural strategies to promote self-management. Baseline, 3, 6, 9 and 12-month interviews assessed patients' self-care practices, self-efficacy for managing depression and depressive symptoms. RESULTS: Intervention patients had significantly greater self-efficacy for managing depression (P<0.01) and were more likely to keep track of depressive symptoms (P<0.0001), monitor early warning signs (P<0.0001), and plan for coping with high risk situations (P<0.0001) at all time points compared to usual care control patients. Self-efficacy for managing depression (P<0.0001), keeping track of depressive symptoms (P=0.05), monitoring for early warning signs (P=0.01), engaging in pleasant activities (P<0.0001) and engaging in social activities (P<0.0001) positively predicted improvements in depression symptom scores. CONCLUSIONS: A brief intervention designed to target cognitive-behavioural factors and promote adherence to pharmacotherapy in order to prevent depression relapse was highly successful in changing several behaviours related to controlling depression. Improvements in self-efficacy and several self-management behaviours that were targets of the intervention were significantly related to improvements in depression outcome. 相似文献