全文获取类型
收费全文 | 15352篇 |
免费 | 1156篇 |
国内免费 | 74篇 |
专业分类
耳鼻咽喉 | 198篇 |
儿科学 | 462篇 |
妇产科学 | 491篇 |
基础医学 | 1594篇 |
口腔科学 | 409篇 |
临床医学 | 1959篇 |
内科学 | 3197篇 |
皮肤病学 | 363篇 |
神经病学 | 773篇 |
特种医学 | 656篇 |
外国民族医学 | 5篇 |
外科学 | 2118篇 |
综合类 | 427篇 |
一般理论 | 8篇 |
预防医学 | 1013篇 |
眼科学 | 379篇 |
药学 | 1411篇 |
1篇 | |
中国医学 | 168篇 |
肿瘤学 | 950篇 |
出版年
2023年 | 178篇 |
2022年 | 379篇 |
2021年 | 690篇 |
2020年 | 431篇 |
2019年 | 566篇 |
2018年 | 673篇 |
2017年 | 474篇 |
2016年 | 558篇 |
2015年 | 585篇 |
2014年 | 725篇 |
2013年 | 853篇 |
2012年 | 1135篇 |
2011年 | 1148篇 |
2010年 | 796篇 |
2009年 | 578篇 |
2008年 | 763篇 |
2007年 | 769篇 |
2006年 | 682篇 |
2005年 | 615篇 |
2004年 | 502篇 |
2003年 | 417篇 |
2002年 | 384篇 |
2001年 | 231篇 |
2000年 | 183篇 |
1999年 | 206篇 |
1998年 | 168篇 |
1997年 | 154篇 |
1996年 | 152篇 |
1995年 | 139篇 |
1994年 | 112篇 |
1993年 | 97篇 |
1992年 | 92篇 |
1991年 | 111篇 |
1990年 | 88篇 |
1989年 | 111篇 |
1988年 | 81篇 |
1987年 | 81篇 |
1986年 | 76篇 |
1985年 | 73篇 |
1984年 | 53篇 |
1983年 | 36篇 |
1982年 | 40篇 |
1981年 | 41篇 |
1980年 | 41篇 |
1979年 | 45篇 |
1978年 | 42篇 |
1977年 | 36篇 |
1976年 | 23篇 |
1975年 | 39篇 |
1973年 | 19篇 |
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
21.
22.
Ahmad Sallehuddin Abdulrahman Mesned Maie Barakati Majid Al Fayyadh Fadel Fadley Zohair Al-Halees 《European journal of cardio-thoracic surgery》2007,32(2):195-200; discussion 201
OBJECTIVE: There are several modifications introduced in the preparation for a subsequent non-surgical transcatheter completion of the Fontan procedure. We report our experience with one type of the modification and the short-term results following its implementation. METHODS: During bidirectional cavopulmonary connection (BCPC) an intra-atrial lateral tunnel is additionally created, as intended for a Fontan procedure but fenestrated with a 10-14 mm aperture. The cardiac end of the superior vena cava (SVC) is then patched to maintain the physiology of BCPC. During the interventional transcatheter completion procedure, the SVC patch is perforated using radio-frequency (RF) energy, balloon-dilated, and stented as well. The aperture is closed with a device when required. Paired t-test was used to compare data before and after the Fontan completion. RESULTS: From June 2003 to February 2006, 16 patients (9 boys and 7 girls, mean age 12 months) underwent the surgical procedure described. The mean bypass time was 137 min and the mean ischemic time was 77 min. There were no operative deaths. One patient with bilateral SVC required a take down due to recurrent effusions. Ten months later, nine patients underwent completion (mean age 20 months, mean weight 10.6 kg). The stents were dilated to a mean diameter of 14.4mm. All except one aperture was closed with a device. The mean fluoroscopy time was 41 min. Oxygen saturation increased from 85 to 94% (p=0.001). Pulmonary artery pressures remained normal (16 mmHg before and 19 mmHg after, p=0.12). No patients required mechanical ventilation and none developed pleural effusions or arrhythmias. All were discharged from hospital within 6 days of the Fontan completion. Twenty-two months after Fontan, all were well. Echocardiography revealed no gradients across the stents. Two patients had minor leaks across the aperture. One underwent further stent dilatation a year later. CONCLUSIONS: Fontan completion without surgery is suitable in patients with single ventricles with lower mortality and morbidity, avoids multiple surgical interventions while maintaining the staged approach and allows for successive dilatation of the Fontan pathway to accommodate for growth. 相似文献
23.
Initially, there is a high incidence of CNS-depressant side-effects when the aromatase inhibitor, aminoglutethimide, is used in the treatment of patients with advanced breast cancer. Tolerance to these effects develops with continued dosing. This study examines the development of tolerance to various indices of CNS depression with the drug in mice. Single doses of aminoglutethimide induced a dose-dependent depression of spontaneous locomotor activity, rotarod performance, righting reflex and body temperature and a dose-related antileptazol activity. On repeated dosing with the drug, tolerance to these various activities occurred. The tolerance was found to be dose-dependent in the rotarod and righting reflex tests and time-dependent in the locomotor and body temperature tests. Although the results do not allow a determination of whether this clearly demonstrated phenomenon in the mouse is primarily functional or dispositional, the slow onset (14 days) for complete tolerance may be indicative of a functional mechanism. 相似文献
24.
G Ahmad 《Journal of toxicology. Clinical toxicology》1987,25(4):341-346
Emergency Room patients at Riverside General Hospital who are found by the attending physician to have depressed sensorium and altered personality are routinely subjected to urine tests for various drugs of abuse including phencyclidine (PCP). The findings of the laboratory analysis of these patients are presented in this paper. The toxicology laboratory of this hospital performs screening procedures for various drugs on urine specimens by thin layer chromatography. Drugs detected are confirmed by gas chromatography and a homogeneous enzyme immunoassay technique. In 1981, 1.6% of the urine specimens of patients in the above-mentioned category were found to be positive for PCP. This percentage increased sharply during 1982 (5.8%) and 1983 (5.6%). During 1984 and 1985 the percentage dropped to 4.2% and 4.6%. It is implied from data that the abuse of this drug in this area has leveled off. The data also indicated that PCP is predominantly used by young adults with ages ranging from 21 to 30 years. The abuse of this drug in people over 40 years of age is comparatively very small. Among users of this drug, 67.5% are men and 32.5% are women. Out of 68 women found to be abusing PCP, 5 delivered their babies in this hospital. PCP was detected in the urine specimens of each of these babies. Four out of the five infants showed withdrawal symptoms such as extreme irritability, jitteriness, hyperactivity with high pitched cries and a poor ability to take food. 相似文献
25.
V Schleyer† S Radakovic-Fijan‡ S Karrer† T Zwingers§ A Tanew‡ M Landthaler† RM Szeimies† 《Journal of the European Academy of Dermatology and Venereology》2006,20(7):823-828
BACKGROUND: Based on good results in the treatment of superficial skin tumours, since the early 1990s topical photodynamic therapy with aminolaevulinic acid (ALA PDT) has been used for disseminated, inflammatory dermatoses including psoriasis. However, there is still a lack of well-documented trials. OBJECTIVE: A prospective randomized, double-blind phase I/II intrapatient comparison study was conducted in 12 patients to investigate whether topical ALA PDT is an effective treatment for chronic plaque-type psoriasis. METHODS: In each patient three psoriatic plaques were randomly treated with a light dose of 20 J/cm(2) and 0.1%, 1% and 5% ALA, respectively. Treatment was conducted twice a week until complete clearance or for a maximum of 12 irradiations. Therapeutic efficacy was assessed by weekly determination of the psoriasis severity index (PSI). RESULTS: The mean percentage improvement was 37.5%, 45.6% and 51.2% in the 0.1%, 1% and 5% ALA-treated groups, respectively. Irradiation had to be interrupted several times because of severe burning and pain sensation. CONCLUSION: Topical ALA PDT did not prove to be an appropriate treatment option for plaque-type psoriasis due to disappointing clinical efficacy, the time-consuming treatment procedure and its unfavourable adverse event profile. 相似文献
26.
27.
Sir, I read with great interest the letter by Higgins and co-workers[1]. 相似文献
28.
29.
30.
Intravenous captopril in congestive heart failure 总被引:1,自引:0,他引:1
S Ahmad T D Giles L E Roffidal Y Haney M B Given G E Sander 《Journal of clinical pharmacology》1990,30(7):609-614
Hemodynamic and neurohumoral effects of intravenous captopril were studied in ten patients with severe chronic congestive heart failure (NYHA Functional Class III and IV). Incremental bolus doses of captopril, titrated to a maximum cumulative dose of 15 mg, were given at 10-minute intervals. Systemic arterial pressure, mean pulmonary capillary wedge pressure, systemic vascular resistance, mean pulmonary artery pressure, and heart rate decreased (P less than .05). Cardiac index and stroke volume index increased (P less than .05). Maximum hemodynamic effects occurred after cumulative doses of 7 mg and were seen within 30 minutes after initiation of therapy; responses persisted for 30-90 minutes after the last dose. Plasma renin activity increased, and plasma atrial natriuretic factor concentration decreased. No adverse effects were observed with the use of intravenous captopril. Thus, intravenous captopril produces rapid and favorable hemodynamic improvement in advanced heart failure patients. 相似文献