全文获取类型
收费全文 | 28224篇 |
免费 | 1701篇 |
国内免费 | 205篇 |
专业分类
耳鼻咽喉 | 279篇 |
儿科学 | 669篇 |
妇产科学 | 679篇 |
基础医学 | 3288篇 |
口腔科学 | 992篇 |
临床医学 | 2606篇 |
内科学 | 6185篇 |
皮肤病学 | 565篇 |
神经病学 | 1563篇 |
特种医学 | 738篇 |
外国民族医学 | 6篇 |
外科学 | 3867篇 |
综合类 | 766篇 |
一般理论 | 21篇 |
预防医学 | 2200篇 |
眼科学 | 1026篇 |
药学 | 2681篇 |
中国医学 | 306篇 |
肿瘤学 | 1693篇 |
出版年
2024年 | 38篇 |
2023年 | 369篇 |
2022年 | 993篇 |
2021年 | 1489篇 |
2020年 | 983篇 |
2019年 | 1212篇 |
2018年 | 1404篇 |
2017年 | 993篇 |
2016年 | 1051篇 |
2015年 | 1025篇 |
2014年 | 1444篇 |
2013年 | 1697篇 |
2012年 | 2323篇 |
2011年 | 2401篇 |
2010年 | 1400篇 |
2009年 | 1083篇 |
2008年 | 1636篇 |
2007年 | 1527篇 |
2006年 | 1266篇 |
2005年 | 1131篇 |
2004年 | 935篇 |
2003年 | 775篇 |
2002年 | 686篇 |
2001年 | 198篇 |
2000年 | 193篇 |
1999年 | 201篇 |
1998年 | 116篇 |
1997年 | 86篇 |
1996年 | 89篇 |
1995年 | 82篇 |
1994年 | 66篇 |
1993年 | 63篇 |
1992年 | 95篇 |
1991年 | 82篇 |
1990年 | 98篇 |
1989年 | 84篇 |
1988年 | 86篇 |
1987年 | 76篇 |
1986年 | 75篇 |
1985年 | 57篇 |
1984年 | 59篇 |
1983年 | 41篇 |
1982年 | 39篇 |
1981年 | 25篇 |
1980年 | 36篇 |
1979年 | 43篇 |
1977年 | 33篇 |
1976年 | 33篇 |
1974年 | 23篇 |
1973年 | 24篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
41.
42.
Several in vitro methods have been suggested to predict drug-induced haematotoxicity and species differences; the most commonly used being the clonogenic CFU-GM assay. The aim of the current study was to evaluate whether primary lymphocytes from peripheral blood, assayed with a short-term non-clonogenic assay, could be used to detect species differences in drug sensitivity, and offer an alternative to the CFU-GM assay. The effect of 17 different cytotoxic drugs on lymphocytes from human, dog, rat and mouse was evaluated. A higher sensitivity of human than mouse lymphocytes was seen for topotecan and for 3 of 5 antimetabolites tested. Clear species specificity was also seen for the proteasome inhibitor bortezomib where rodent cells were 50-300 times less sensitive than human cells. Good agreement between our data and published CFU-GM data was observed, suggesting that primary lymphocytes may be a useful model for species difference screening in drug development. 相似文献
43.
Despite the controversy of airway responsiveness to beta2-agonist drugs in asthma, in a previous study we showed increased responsiveness of asthmatic airways to isoprenaline. Therefore, in the present study of airway sensitivity to other beta2-agonists, salbutamol and its relationship to histamine responsiveness was reexamined. The threshold bronchodilator concentrations of inhaled salbutamol required for a 20% increase in forced expiratory flow in 1 sec (FEV1), (PC20) was measured in 20 normal and 19 asthmatic adults. Airway responsiveness to histamine, as the concentration that caused a 20% decrease in FEV1, was also measured in 11 normal and 12 asthmatic subjects; and the correlation between PC20 salbutamol and PC20 histamine was evaluated. Sensitivity to salbutamol was greater in asthmatics (PC20 = 7.24 mg/L) than in non-asthmatics (PC20 = 124.25 mg/L, p < 0.001). Airway responsiveness to histamine in asthmatics (PC20 = 0.18 g/L) was also significantly greater than in normal subjects (PC20 = 19.46 g/L, p < 0.001). There was a significant correlation between PC20 salbutamol and histamine (Rs = 0.6052, p < 0.005). Maximum response to both salbutamol and histamine and slope of concentration-response curves of both agents were significantly greater in patients with asthma than in normal subjects (p < 0.001 and p < 0.005 for maximum response and slope, respectively). The increased sensitivity of asthmatics to inhaled salbutamol suggests that they also may be more sensitive to their endogenous adrenaline, which may thus dilate and stabilize their airways. 相似文献
44.
Duane retraction syndrome has been reported in association with structural abnormalities of the eye, including epibulbar dermoid, keratoconus, iris dysplasia, heterochromia iridis, persistent fetal vasculature, cataract, choroidal coloboma, microphthalmia, and optic nerve dysplasia. A novel association, that of bilateral Duane syndrome with bilateral aniridia, is the subject of this report. 相似文献
45.
Sedigheh Sadat Tavafian Ahmadreza Jamshidi Kazem Mohammad Ali Montazeri 《BMC musculoskeletal disorders》2007,8(1):21
Background
Different interventions can reduce the burden of the chronic low back pain. One example is the use of a 'Back School Programme'. This is a brief therapy that uses a health education method to empower participants through a procedure of assessment, education and skill development. This study aimed to evaluate to what extent the programme could improve quality of life in those who suffer from the condition. 相似文献46.
Mustafa Hassan Kaki M. York Haihong Li Qin Li David S. Sheps 《Journal of nuclear cardiology》2007,14(3):308-313
Background Reduced left ventricular ejection fraction (LVEF) is a risk factor for poor outcomes in patients with coronary artery disease
(CAD). Mental stress-induced myocardial ischemia (MSIMI) also identifies a subset of CAD patients at increased risk for future
cardiovascular events. Susceptibility to MSIMI in patients with CAD and reduced LVEF is unknown.
Methods and Results We enrolled 182 patients (67 women) with a mean age of 64 years and a documented history of CAD in this study. Baseline resting
ejection fraction was determined by use of technetium 99m sestamibi gated single photon emission computed tomography. Abnormal
LVEF was defined as less than 45% for men and less than 50% for women (based on published norms for our software [Cedars-Sinai
Medical Center]). All participants underwent mental stress testing with a public speaking task. Rest/stress myocardial perfusion
single photon emission computed tomography was performed via conventional methodology. Images were visually compared for number
and severity of perfusion defects by use of a scoring method from 0 to 4. A summed difference score was calculated as the
difference between summed stress and rest scores. A score of greater than 3 was considered abnormal. MSIMI developed in 19%
of patients with normal LVEF and 31% of those with reduced LVEF. There is no statistically significant difference between
the two groups (P=.11).
Conclusions CAD patients with left ventricular dysfunction are equally susceptible to MSIMI as those with normal LVEF.
This study was supported by grants HL 070265 and HL 072059 from the National Heart. Lung, and Blood Institute. This material
is also the result of work supported by resources and with the use of facilities at the Department of Veterans. Affairs Medical
Center, Gainesville, Fla. 相似文献
47.
Laparoscopic flip-flap technique versus conventional inguinal hernia repair in children. 总被引:1,自引:0,他引:1
Mohamed E Hassan A R Mustafawi 《JSLS, Journal of the Society of Laparoendoscopic Surgeons》2007,11(1):90-93
BACKGROUND AND OBJECTIVES: Inguinal hernia repair is one of the most frequently performed pediatric surgical operations. Several pediatric laparoscopic inguinal hernia repair techniques have been introduced. But debate is unresolved regarding the feasibility of laparoscopy for treating pediatric inguinal hernias. METHODS: A retrospective cohort study enrolled 33 patients who underwent congenital inguinal hernia repair by either the new laparoscopic flip-flap technique or conventional open repair. Patients were divided into 2 groups according to the type of surgery: Group A included those who underwent the new laparoscopic technique, and Group B included those who underwent conventional open repair. RESULTS: Group A comprised 15 patients (mean age, 39 months), and group B comprised 18 (mean age, 44 months). Mean operative time was 47.5 minutes for Group A versus 27.5 minutes for Group B. Intraoperative complications for Group A included 1 case (7%) of vas deferens injury, and 3 cases (20%) in which the flaps were torn during suturing. In Group B, no intraoperative complications were encountered. In both groups, the mean postoperative hospital stay was 5.5 hours. Postoperative follow-up of 3 months revealed recurrence in 4 patients in Group A (27%), while there were no recurrences in Group B. CONCLUSION: Our preliminary experience shows unsatisfactory outcomes with laparoscopic flip-flap hernia repair in children. In spite of advancement in the application of laparoscopy in pediatric surgery, conventional open hernia repair is still the gold standard for children, in our experience. Future studies with more numbers and longterm follow-up should be conducted. 相似文献
48.
Mohammad H. Ebrahimzadeh MD Mohammad T. Rajabi MD 《The Journal of foot and ankle surgery》2007,46(6):429-433
Long-term clinical and functional outcomes for patients undergoing foot and ankle amputations are not well documented. We attempted to document long-term outcomes for patients who required lower extremity amputations as a result of wounds suffered during wartime. For this study, 27 Iranian soldiers who had wounds requiring amputation of the foot and ankle were selected for follow-up. The participants' wartime medical records were reviewed, a clinical examination was performed, and each participant completed a questionnaire. Postamputation follow-up averaged 17.5 years. The most prevalent (66.6%) cause of injury was a land mine. The prevalences of different clinical symptoms reported by the amputees at the time of the last follow-up were as follows: 11 (40.7%) with phantom sensation, 6 (22.2%) with phantom pain, 12 (44.4%) with stump pain, 12 (44.4%) with back pain, 9 (33.3%) with contralateral knee pain, and 4 (14.8%) with ipsilateral knee pain; 20 (74%) reported treatment for psychological conditions. In regard to social conditions, 13 (48.1) were currently employed, or had been employed, for a number of years after the amputation; 26 (96%) had children, and all of the patients were married. The results of this observational study indicate that individuals have significant long-term pain and discomfort after war-related lower extremity amputation. Although all 27 (100%) of the amputees were able to maintain satisfactory family functioning, only 13 (48.1%) of the study participants were able to remain productively employed after undergoing amputation, and 20 (74%) reported long-term psychological problems in addition to their physical pain. 相似文献
49.
Jean-Francois Légaré Ansar Hassan Karen J Buth John A Sullivan 《Journal of cardiothoracic surgery》2007,2(1):44-8
Background
While it is believed that total arterial grafting (TAG) for coronary artery bypass grafting (CABG) confers improved long-term outcomes when compared to conventional grafting with left internal mammary artery and saphenous vein grafts (LIMA+SVG), to date, this has not become the standard of care. In this study, we assessed the impact of TAG on medium-term outcomes after CABG. 相似文献50.