全文获取类型
收费全文 | 3808篇 |
免费 | 329篇 |
国内免费 | 23篇 |
专业分类
耳鼻咽喉 | 44篇 |
儿科学 | 58篇 |
妇产科学 | 36篇 |
基础医学 | 434篇 |
口腔科学 | 148篇 |
临床医学 | 353篇 |
内科学 | 872篇 |
皮肤病学 | 74篇 |
神经病学 | 232篇 |
特种医学 | 111篇 |
外科学 | 551篇 |
综合类 | 204篇 |
预防医学 | 260篇 |
眼科学 | 218篇 |
药学 | 186篇 |
中国医学 | 32篇 |
肿瘤学 | 347篇 |
出版年
2023年 | 40篇 |
2022年 | 63篇 |
2021年 | 123篇 |
2020年 | 96篇 |
2019年 | 104篇 |
2018年 | 164篇 |
2017年 | 107篇 |
2016年 | 102篇 |
2015年 | 123篇 |
2014年 | 161篇 |
2013年 | 176篇 |
2012年 | 229篇 |
2011年 | 296篇 |
2010年 | 147篇 |
2009年 | 127篇 |
2008年 | 209篇 |
2007年 | 215篇 |
2006年 | 236篇 |
2005年 | 163篇 |
2004年 | 205篇 |
2003年 | 179篇 |
2002年 | 120篇 |
2001年 | 97篇 |
2000年 | 87篇 |
1999年 | 74篇 |
1998年 | 23篇 |
1997年 | 23篇 |
1996年 | 21篇 |
1995年 | 13篇 |
1994年 | 10篇 |
1993年 | 18篇 |
1992年 | 39篇 |
1991年 | 44篇 |
1990年 | 37篇 |
1989年 | 37篇 |
1988年 | 43篇 |
1987年 | 31篇 |
1986年 | 32篇 |
1985年 | 16篇 |
1984年 | 11篇 |
1983年 | 15篇 |
1980年 | 8篇 |
1979年 | 13篇 |
1977年 | 10篇 |
1976年 | 5篇 |
1975年 | 8篇 |
1974年 | 9篇 |
1972年 | 7篇 |
1971年 | 8篇 |
1970年 | 6篇 |
排序方式: 共有4160条查询结果,搜索用时 0 毫秒
1.
J C Ho M Chan-Yeung S P Ho J C Mak M S Ip G C Ooi M P Wong K W Tsang W K Lam 《The European respiratory journal》2007,29(2):273-278
The present study aimed to determine the alterations of antioxidant activities in erythrocytes from patients with nonsmall cell lung carcinoma (NSCLC). A comparative study of the systemic antioxidant activities in red blood cell lysate from subjects with NSCLC and healthy control subjects was conducted. The antioxidants catalase, superoxide dismutase (SOD) and glutathione peroxidase (GPx) were measured using chemical kinetic reactions under spectrophotometry. In total, 189 cases of mostly advanced-stage IIIB or stage IV NSCLC and 202 healthy controls were studied. In subjects with lung cancer, there was similar catalase activity, lower SOD activity (median (interquartile range) 13.4 (9.0-27.2) versus 48.7 (27.0-64.3) U x (ghaemoglobulin(Hb)(-1)), and higher GPx activity (175.2 (126.6-288.3) versus 49.2 (39.5-59.2) mU x (gHb)(-1)) compared with controls. The antioxidant activities in lung cancer subjects were not associated with age, sex, smoking status, or tumour cell types. However, more advanced disease (stage IV compared with stage IIIB) was associated with lower SOD activity. Using multivariable analysis, the presence of lung cancer independently predicted SOD and GPx activities. In conclusion, nonsmall cell lung carcinoma in Chinese subjects is associated with alterations in systemic antioxidant activities, which may play an important role in carcinogenesis. 相似文献
2.
3.
A 44-year-old female with Cushing's disease associated with a pituitary macroadenoma was treated with cyproheptadine, 24 mg per day, after partial surgical resection of the tumor. A large residual tumor remained. There was no clear suppression of serum and urinary cortisol during therapy, but both levels rose markedly to beyond pre cyproheptadine levels, on withdrawal of the drug. This is the first report on the use of cyproheptadine in Cushing's disease associated with a pituitary macroadenoma. The response in this patient indicates an influence of cyproheptadine on ACTH secretion by the macroadenoma. 相似文献
4.
5.
6.
7.
PURPOSE: We report an unusual case of vocal cord edema associated with the use of a ProSeal laryngeal mask airway (PLMA) in an adult patient with an undiagnosed upper respiratory tract infection (URTI). CLINICAL FEATURES: A 55-yr-old woman had fixation of a radial fracture under general anesthesia with muscle relaxation. She developed audible wheezing 30 min after PLMA insertion. Bronchoscopic examination revealed significant vocal cord edema. Adequate ventilation was possible at increased airway pressures, and the administration of dexamethasone 4 mg iv produced clinical resolution of the stridor and airway obstruction. The patient admitted to having mild symptoms of an URTI on postoperative questioning. CONCLUSION: Airway hyperreactivity secondary to the URTI is the most likely etiological factor; other possibilities include trauma from insertion and chemical irritation. Although pediatric studies suggest that the LMA-Classic carries less risk than endotracheal intubation in the presence of URTI, this case report demonstrates that caution is still warranted when using supraglottic airways. The PLMA permitted effective ventilation despite increased airway resistance; nevertheless its role in patients with URTI is unclear. It is possible that the bulkier cuff design of the PLMA, compared to that of the LMA-Classic, may have partly contributed to the development of edema in this setting. 相似文献
8.
9.
10.
M P Marks H Chee R P Liddell G K Steinberg N Panahian B Lane 《AJNR. American journal of neuroradiology》1994,15(5):821
PURPOSETo evaluate mechanically detachable coil designs capable of controlled and instantaneous release within an aneurysm or vascular space.METHODSThree mechanically detachable coil designs, clamped ball, looped ribbon, and interlocking cylinder, were evaluated using in vitro and in vivo testing to study reliability of coil release, retractability, and coil behavior in a microcatheters. In vitro tests were performed using a glass side-wall aneurysm model and conventional microcatheters. In vivo experiments in rabbits included aneurysm models (side-wall and bifurcation) and arterial occlusions (carotid and renal).RESULTSAll three designs deployed coils easily and were able to retract coils after partial deployment. Motion was seen in previously released coils and in the catheter when using the clamped ball and looped ribbon designs. The interlocking cylinder design did not cause similar motion. When compared with the other two designs, the interlocking cylinder had significantly greater separation forces between coil pusher and coil while in the catheter. Frictional forces within the catheter were lower for the interlocking cylinder mechanically detachable coil design than for a commercially available conventional coil and coil pusher system. During in vivo testing, the mechanically detachable coil design operated smoothly in the catheter, providing good release and retraction in aneurysms and straight vessels.CONCLUSIONThe interlocking cylinder mechanically detachable coil design is superior to the other two tested designs. The mechanically detachable coil was reliably delivered and detached in in vivo testing for the treatment of aneurysms and for the occlusion of blood vessels. 相似文献