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   413781篇
  免费   21455篇
  国内免费   14442篇
耳鼻咽喉   3317篇
儿科学   9538篇
妇产科学   7835篇
基础医学   44245篇
口腔科学   5755篇
临床医学   43204篇
内科学   69889篇
皮肤病学   3464篇
神经病学   29558篇
特种医学   17368篇
外国民族医学   98篇
外科学   54818篇
综合类   36522篇
现状与发展   50篇
一般理论   45篇
预防医学   32956篇
眼科学   9399篇
药学   33500篇
  177篇
中国医学   11580篇
肿瘤学   36360篇
  2024年   716篇
  2023年   3511篇
  2022年   8739篇
  2021年   11493篇
  2020年   8467篇
  2019年   7597篇
  2018年   29165篇
  2017年   23804篇
  2016年   25609篇
  2015年   11008篇
  2014年   13564篇
  2013年   12692篇
  2012年   24316篇
  2011年   39671篇
  2010年   30069篇
  2009年   20651篇
  2008年   31855篇
  2007年   34121篇
  2006年   12960篇
  2005年   14608篇
  2004年   11885篇
  2003年   11897篇
  2002年   9089篇
  2001年   6304篇
  2000年   6574篇
  1999年   6639篇
  1998年   3884篇
  1997年   3919篇
  1996年   2907篇
  1995年   2701篇
  1994年   2335篇
  1993年   1563篇
  1992年   2331篇
  1991年   2086篇
  1990年   1794篇
  1989年   1534篇
  1988年   1319篇
  1987年   1218篇
  1986年   970篇
  1985年   778篇
  1984年   510篇
  1983年   402篇
  1982年   249篇
  1981年   203篇
  1980年   231篇
  1979年   245篇
  1978年   149篇
  1977年   115篇
  1976年   105篇
  1974年   135篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Statutory reimbursement agencies as well as private insurers throughout member states of the Organization for Economic Cooperation and Development (OECD) reimburse the cost of medicines on the basis of criteria that include robust clinical evidence, budget impact analysis, and incremental cost effectiveness. The Centers for Medicare and Medicaid Services (CMS) in the US are no exception to this rule and are, in principle, seeking to maximize benefit for their Medicare enrollees, whilst ensuring reasonable drug outlays for the small number of drugs that they reimburse. This paper provides a retrospective analysis of the way two functionally equivalent drugs are treated for reimbursement purposes by the CMS; the period under consideration was 2001–3. The two drugs, epoetin-α and darbepoetin-α, are used for the treatment of anemia in renal failure and in patients receiving chemotherapy. By reviewing the publicly available pharmacological and clinical data of epoetin-α and darbepoetin-α, the paper confirms the two drugs’ functional equivalence, despite their structural differences. The implications of dose conversion ratios and costs to Medicare are subsequently explored. It is argued that the issue of dose equivalence between epoetin-α and darbepoetin-α has significant implications for patients, practitioners, and payors. A payor’s perspective is adopted in this respect, whereby clinical evidence and pricing data are used simultaneously. Based on the clinical evidence, a dose conversion ratio for epoetin-α:darbepoetin-α is established, which achieves a comparable clinical effect for the two drugs and this is set to be <254IU:1μg. The incremental costs to Medicare are calculated subsequently. The Average Wholesale Price and the Outpatient Prospective Payment System rule that Medicare uses to reimburse providers are used and suggest that treatment of cancer patients with chemotherapy-related anemia with epoetin-α would save Medicare an estimated $US600 million each year. Patients would also benefit significantly in terms of lower co-payments for epoetin-α. The evidence is supportive of the decision made by the CMS to reimburse the two drugs at the rate reflecting the achievement of comparable clinical effects and therefore reducing the pass-through payments for darbepoetin-α to zero for the 2002–3 fiscal year.  相似文献   
82.
经腹及经阴道B超监测卵泡发育的评估   总被引:3,自引:0,他引:3  
应用经腹及经阴道B超对68名不孕症妇女,139个月经周期进行卵泡发育及排卵监测。卵泡检出率TAUS为90.6%,TVUS为98.0%,显著高于前者,P<0.05。成熟卵泡特征影象(卵丘等)在TVUS显象率较高。TVUS监测卵泡发育更实用可靠。  相似文献   
83.
84.
ABSTRACT: Klinefelter syndrome occurs in approximately 1 in 1000 males. A 4-year-old boy presented with precocious puberty and an anterior mediastinal mass. Serum alpha-fetoprotein and human chorionic gonadotropin levels were mildly increased. Computed tomography revealed a germ cell tumor (GCT) of the mediastinum. Complete resection of the tumor was performed. Histologic analysis revealed an immature teratoma. Males with Klinefelter syndrome develop GCTs at a rate 50 times higher than unaffected males. This case report calls attention to the need to rule out Klinefelter syndrome in boys who present with precocious puberty and a mediastinal GCT.  相似文献   
85.
以钒基核苷酸复合物为核酸酶抑制剂,从人胚组织中制备总RNA,所得产品几乎不含DNA和蛋白质,经过分离Poly(A)~ mRNA,证明制品有合成cDNA的完整功能,方法比较简捷,适于大量制备以满足分离mRNA 之需,并讨论了此法的优缺点。  相似文献   
86.
1例脊髓空洞症侧脑室延髓池内分流术的护理   总被引:1,自引:0,他引:1  
唱荣艳  陈荣莉  薛艳娥 《护理研究》2005,19(30):2819-2819
1 病例介绍病人,男,34岁,左下肢步态不稳10年,加重伴酸麻、隐痛1年,于2004年4月入院.入院时精神欠佳,生活不能完全自理,左上肢肱二腱、肱三腱反射和下肢膝反射亢进,右上肢肱二腱、肱三腱反射减弱,右前臂及手部触觉消失,左下肢膝关节以下触觉、位置觉、浅感觉消失.MRI示脊髓空洞症.术前检查未发现手术禁忌证,行全身麻醉下环枕畸形减压、侧脑室延髓池内分流术.手术顺利,术中输红细胞悬液400 mL,放置皮下引流管1根,术后恢复好,无并发症发生,病人生活上基本自理,出院随访1年,情况良好.……  相似文献   
87.
88.
89.
Abstract We report a case of SMV injury in a critically ill patient. The patient was a 19-year-old woman involved in a motor vehicle collision. Her injuries included grade II splenic and renal lacerations, devascularized and lacerated right and transverse colon, a transected transverse mesocolon, a massive shear injury of her abdominal wall, and two partial SMV transections. At initial damage control laparotomy, the SMV was ligated, the devascularized bowel resected and a temporary abdominal closure applied. At re-operation, a mesocaval shunt using saphenous vein was employed. The shunt failed and the patient required a saphenous vein jump graft. Although visceral vascular injuries are rare, ligation of the SMV in a damage control situation is acceptable. This case study is the first to discuss appropriate treatment when interruption to a patient's collateral visceral venous drainage limits the surgeon’s ability to ligate. In these situations, bypass shunts may be successful.  相似文献   
90.
腹腔镜肝右后叶囊肿开窗引流术35例报告   总被引:6,自引:1,他引:5  
目的:探讨肝右后叶肝囊肿的腹腔镜处理方法。方法:1998年1月~2005年12月对35例有症状的肝右后叶囊肿(21例主要位于Ⅵ段,14例主要位于第Ⅶ段)采用四孔法行囊肿开窗引流术。囊肿位于肝右后叶上段者采用肝上入路,胆囊牵引钳或三叶钳推压肝脏使其向前向下,暴露肝后囊肿,囊肿开窗,修剪带蒂大网膜放入囊肿。囊肿位于肝右后叶下段者采用肝下入路,超声刀切开肝结肠韧带,右三角韧带及肝肾间疏松组织,胆囊牵引钳抬起肝脏,囊肿开窗,大网膜放入囊腔引流。结果:35例肝右后叶肝囊肿均在腹腔镜下完成肝囊肿开窗引流术,无中转开腹手术。15例采用肝上入路,20例采用肝下入路。手术时间30~95min,平均46min。无手术并发症。35例病理检查结果均为先天性肝囊肿。术后症状均消失。术后住院2~5d,平均3.8d。35例随访6~36个月,平均34个月,33例无复发,2例(为肝上入路病例)囊肿未完全消失,但较术前明显缩小,无明显症状,观察半年未见增大。结论:肝下及肝上入路囊肿开窗引流是腹腔镜下处理肝右叶肝囊肿的有效方法。  相似文献   
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