首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   82309篇
  免费   7390篇
  国内免费   5489篇
耳鼻咽喉   852篇
儿科学   887篇
妇产科学   1240篇
基础医学   10618篇
口腔科学   1404篇
临床医学   10927篇
内科学   12333篇
皮肤病学   1026篇
神经病学   4521篇
特种医学   3098篇
外国民族医学   54篇
外科学   8576篇
综合类   10917篇
现状与发展   21篇
一般理论   22篇
预防医学   5139篇
眼科学   2986篇
药学   8553篇
  68篇
中国医学   4217篇
肿瘤学   7729篇
  2024年   261篇
  2023年   1225篇
  2022年   3198篇
  2021年   4129篇
  2020年   3026篇
  2019年   2909篇
  2018年   3084篇
  2017年   2555篇
  2016年   2658篇
  2015年   3824篇
  2014年   4755篇
  2013年   4181篇
  2012年   6203篇
  2011年   6646篇
  2010年   4095篇
  2009年   3098篇
  2008年   4306篇
  2007年   4159篇
  2006年   4262篇
  2005年   4094篇
  2004年   2781篇
  2003年   2554篇
  2002年   2100篇
  2001年   1806篇
  2000年   1782篇
  1999年   2069篇
  1998年   1306篇
  1997年   1269篇
  1996年   963篇
  1995年   910篇
  1994年   774篇
  1993年   485篇
  1992年   597篇
  1991年   499篇
  1990年   477篇
  1989年   413篇
  1988年   371篇
  1987年   302篇
  1986年   249篇
  1985年   212篇
  1984年   131篇
  1983年   86篇
  1982年   42篇
  1981年   55篇
  1980年   30篇
  1979年   63篇
  1978年   22篇
  1974年   27篇
  1973年   18篇
  1968年   16篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
目的探讨关节镜下松解术治疗冻结肩的疗效.方法2001年10月~2003年10月,我院对25例冻结肩在关节镜下行松解术.全麻下肩关节后路进镜,前路进射频电刀烧灼肱二头肌长头肌腱及肩袖间隙部位的滑膜充血炎症区,切割盂肱上韧带、盂肱中韧带、肩胛下肌肌腱关节囊内部分,手法松解剩余挛缩.25例术后3、6个月随访肩关节活动范围及美国肩肘协会评分(ASES).结果手术时间75~98 min,平均85 min.无术中并发症.25例除术后1周肩关节内旋与术前无明显改善外(x2=8.558,P=0.073),术后各个时期肩关节其它活动范围比术前均有明显改善(P<0.05).术后3个月和6个月比术后1周改善更明显(P<0.05).25例术后3个月和6个月ASES评分(87.4±4.6,88.1±6.0)均比术前(45.8±10.0)明显改善(q=28.738,29.221;P<0.05),但3个月与6个月评分相比较无显著性差异(q=0.484,P>0.05).结论肩关节镜下手术松解冻结肩可以明显缩短病程,取得稳定满意的效果.  相似文献   
992.
目的:分析经直肠超声(TRUS)引导下穿刺活检诊断前列腺癌的漏诊原因,减少漏诊率,提高诊断率。方法:80例疑似前列腺癌的良性前列腺增生(BPH)患者行TRUS引导下穿刺活检,结果均为阴性,均行前列腺电切术(TURP),术后标本行病理检查。结果:25例术后病理报告为前列腺癌,漏诊率31.25%(25/80)。其中10例行经会阴前列腺癌根治术、8例行手术去势、7例行药物去势。结论:TRUS引导穿刺活检诊断前列腺癌存在一定的漏诊,多次或多点穿刺活检可以减少漏诊率。  相似文献   
993.
门静脉血栓的综合治疗   总被引:1,自引:0,他引:1  
目的:探讨门静脉血栓的临床诊断及综合治疗。方法:45例中非手术治疗27例,介入溶栓10例,手术8例。结果:3例治愈,42例好转。结论:提高对本病的认识,及时辅以必要的辅助检查,是早期诊断的关键 选择个性化的治疗方案,是综合治疗成功的关键。  相似文献   
994.
Background  Radiosurgery is an effective treatment option for patients with small to medium sized arteriovenous malformations. However, it is not generally accepted as an effective tool for larger (>14 cm3) arteriovenous malformations because of low obliteration rates. The authors assessed the applicability and effectiveness of radiosurgery for large arteriovenous malformations. Method  We performed a retrospective study of 46 consecutive patients with more than 14 ml of arteriovenous malformations who were treated with radiosurgery using a linear accelerator and gamma knife (GK). They were grouped according to their initial clinical presentation—17 presented with and 29 without haemorrhage. To assess the effect of embolization, these 46 patients were also regrouped into two subgroups—25 with and 21 without preradiosurgical embolization. Arteriovenous malformations found to have been incompletely obliterated after 3-year follow-up neuroimaging studies were re-treated using a GK. Findings  The mean treatment volume was 29.5 ml (range, 14.0–65.0) and the mean marginal dose was 14.1 Gy (range, 10.0–20.0). The mean clinical follow-up periods after initial radiosurgery was 78.1 months (range, 34.0–166.4). Depending on the results of the angiography, 11 of 33 patients after the first radiosurgery and three of four patients after the second radiosurgery showed complete obliteration. Twenty patients received the second radiosurgery and their mean volume was significantly smaller than their initial volume (P = 0.017). The annual haemorrhage rate after radiosurgery was 2.9% in the haemorrhage group (mean follow-up 73.3 months) and 3.1% in the nonhaemorrhage group (mean follow-up 66.5 months) (P = 0.941). Preradiosurgical embolization increased the risk of haemorrhage for the nonhaemorrhage group (HR, 28.03; 95% CI, 1.08–6,759.64; P = 0.039), whereas it had no effect on the haemorrhage group. Latency period haemorrhage occurred in eight patients in the embolization group, but in no patient in the nonembolization group (P = 0.004). Conclusions  Radiosurgery may be a safe and effective arteriovenous malformation treatment method that is worth considering as an alternative treatment option for a large arteriovenous malformation.  相似文献   
995.
It has become accepted by virtue of rich anecdotal experience and clinical research that thyrotoxicosis is associated with high-turnover osteoporosis. The bone loss, primarily due to accelerated resorption that is not compensated by a coupled increase in bone formation, has been attributed solely to elevated thyroid hormone levels. Evidence using mice lacking the thyroid hormone receptors α and β establishes a role for thyroid hormones in regulating bone remodeling but does not exclude an independent action of thyroid-stimulating hormone (TSH), levels of which are low in hyperthyroid states, even when thyroid hormones are normal, as after thyroxine supplementation and in subclinical hyperthyroidism. We show that TSH directly suppresses bone remodeling and that TSH receptor null mice have profound bone loss, suggesting that reduced TSH signaling contributes to hyperthyroid osteoporosis. TSH and its receptor could become valuable drug targets in treating bone loss.  相似文献   
996.
Background  Pleural disease remains a commonly encountered clinical problem for both physician and surgeon. This study describes a new way to better diagnose and treat pleural diseases (hemothorax, empyema, and pleural effusion) using an electronic endoscope (gastroscope or bronchoscope). Methods  We conducted a retrospective study of the use of an electronic endoscope in the treatment and diagnosis of pleural diseases. From November 2006 to February 2008, a total of 17 patients (3 women, 14 men; mean age = 41.8 years; range = 18–62 years) underwent procedures for thoracic empyema (13 patients), traumatic clotted hemothorax (3 patients), and undiagnosed pleural effusion (1 patient). The electronic endoscope was inserted via the thoracic drainage tube for the treatment or diagnosis of pleural diseases after regular treatments, including thoracentesis, tube thoracostomy, and biopsy, failed. Results  All patients were cured and discharged from hospital and were followed up for 6 months. The patients recovered well and there was no recurrence. Conclusion  The technique of inserting an electronic endoscope into the thoracic drainage tube for diagnosis and treatment of pleural diseases is simple, effective, minimally invasive, and cost-effective.  相似文献   
997.
Background: The aim of this study was to assess the preventive effect of xuezhikang (XZK) to replace atorvastatin on the contrast media-induced acute kidney injury (CI-AKI).

Methods: The male Sprague–Dawley rats were divided into five groups: group 1 (sham), injected with normal saline; group 2 (XZK), treated with XZK; group 3 contrast media (CM), injected with CM; group 4 (CM?+?ATO), injected with CM?+?pretreatment with atorvastatin; group 5 (CM?+?XZK), injected with CM?+?pretreatment with XZK. Twenty-four hours after injection with normal saline or CM, the blood sample and the kidneys were collected for the measurement of biochemical parameters, oxidative stress markers, nitric oxide production, inflammatory parameters, as well as renal histopathology and apoptosis detection.

Results: Our results indicated that XZK restored the renal function by reducing serum blood urea nitrogen (BUN) and serum creatinine (Scr), depressing renal malondialdehyde (MDA), increasing renal NO production, decreasing TNF-ɑ and IL-6 expression, attenuating renal pathological changes and inhibiting the apoptosis of renal tubular cells.

Conclusion: XZK’s therapeutic effect is similar, or even better than atorvastatin at the same effectual dose in some parts.  相似文献   
998.
Li Sun  Xiao Tan  Xuesen Cao 《Renal failure》2016,38(5):728-737
Objective To analyze the relationship between serum high-sensitivity cardiac troponin T (hs-cTnT) and cardiovascular disease (CVD) among non-dialysis chronic kidney disease (CKD) patients, and to further explore its value of evaluating and predicting CVD in this population. Methods Five hundred and fifty-seven non-dialysis CKD patients were involved in this cross-sectional study. The relationship between serum hs-cTnT and CVD was analyzed using comparison between groups and regression analysis, and its value on assessing cardiac structure and function was evaluated by ROC curves. Results Median level of hs-cTnT was 13 (7–29) ng/L, with 1.7% undetectable, 46.4% greater than 99th percentile of the general population. Multivariate analysis suggested that compared with the lowest quartile of hs-cTnT, the highest quartile was approximately six times as likely to develop into LVH (OR, 6.515; 95% CI, 3.478–12.206, p?<?0.05) and 18 times as likely to progress to left ventricular diastolic dysfunction(OR, 18.741; 95% CI, 2.422–145.017, p?<?0.05). And Ln cTnT level had a more modest association with LVEF (OR, ?1.117; 95% CI, ?5.839 to ?0.594; p?<?0.05). When evaluated as a screening test, the area under the curve of ROC curves for hs-cTnT was 0.718, 0.788 and 0.736, respectively (p?<?0.05). With a specificity of 90% as a diagnostic criterion, the value of hs-cTnT to evaluate LVH, LVEF?Conclusions In CKD non-dialysis population, hs-cTnT and NT-proBNP were valuable for evaluating LVH, left ventricular systolic dysfunction and left ventricular diastolic dysfunction.  相似文献   
999.
This paper addresses an issue on reduced‐order observer‐based robust fault estimation and fault‐tolerant control for a class of uncertain nonlinear discrete‐time systems. By introducing a nonsingular coordinate transformation, a new nonlinear reduced‐order fault estimation observer (RFEO) is proposed with a wide application range in order to achieve an accurate estimation of both states and faults. Next, an improved algorithm is given to obtain the optimal estimation by using a novel iterative linear matrix inequality technique. Furthermore, an RFEO‐based output feedback fault‐tolerant controller, which is independent of the RFEO, can maintain the stability and performance of the faulty system. Simulation results of an aircraft application show the effectiveness of the proposed method. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   
1000.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号