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   54724篇
  免费   3398篇
  国内免费   1132篇
耳鼻咽喉   308篇
儿科学   1218篇
妇产科学   740篇
基础医学   5041篇
口腔科学   764篇
临床医学   6929篇
内科学   10302篇
皮肤病学   275篇
神经病学   2531篇
特种医学   1514篇
外科学   4108篇
综合类   9050篇
现状与发展   3篇
预防医学   6132篇
眼科学   353篇
药学   6172篇
  51篇
中国医学   2946篇
肿瘤学   817篇
  2024年   129篇
  2023年   715篇
  2022年   1495篇
  2021年   2080篇
  2020年   1818篇
  2019年   1454篇
  2018年   1434篇
  2017年   1542篇
  2016年   1719篇
  2015年   1785篇
  2014年   3627篇
  2013年   3840篇
  2012年   3406篇
  2011年   3645篇
  2010年   2840篇
  2009年   2709篇
  2008年   2588篇
  2007年   2415篇
  2006年   2183篇
  2005年   1868篇
  2004年   1577篇
  2003年   1385篇
  2002年   1111篇
  2001年   1078篇
  2000年   971篇
  1999年   789篇
  1998年   700篇
  1997年   696篇
  1996年   592篇
  1995年   563篇
  1994年   530篇
  1993年   482篇
  1992年   433篇
  1991年   390篇
  1990年   366篇
  1989年   326篇
  1988年   347篇
  1987年   322篇
  1986年   277篇
  1985年   341篇
  1984年   352篇
  1983年   218篇
  1982年   295篇
  1981年   243篇
  1980年   256篇
  1979年   201篇
  1978年   179篇
  1977年   165篇
  1976年   131篇
  1973年   133篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
目的:观察中药降糖益肾方合二甲双胍片治疗2型糖尿病的临床疗效.方法:治疗组50例口服降糖益肾方、二甲双胍片.对照组45例口服二甲双胍片.两组均连续用药3个月,监测两组治疗前后空腹及餐后2h血糖(FPG、PG2h)、空腹胰岛素(Fins)血脂(TC、TG)及血液流变学指标变化,并计算胰岛素敏感指数(IAI).结果:治疗组临床症状改善、FPG、PG2h、Fins、TC、TG以及血浆粘比度、红细胞压积、纤维蛋白原与对照组比较明显降低,IAI明显提高(P<0.01、P<0.05).结论:中药降糖益肾方合二甲双胍片治疗2型糖尿病疗效确切.  相似文献   
72.
妊娠期糖耐量受损与妊娠结局的关系   总被引:1,自引:0,他引:1  
①目的 探讨妊娠期糖耐量受损 (GIGT)对妊娠结局的影响。②方法 以妊娠期GIGT孕妇 1 31例(GIGT组 ) ,妊娠期糖尿病 (GDM)孕妇 1 6 6例 (GDM组 ) ,糖耐量正常孕妇 1 6 0例 (正常对照组 )为研究对象 ,对孕妇及其围生儿结局进行对比研究。③结果 GIGT组及GDM组妊娠高血压综合征、巨大儿、羊水过多、胎膜早破、剖宫产及新生儿疾病发生情况均高于对照组 (χ2 =4 .0 2~ 81 .31 ,P <0 .0 5、0 .0 1 )。④结论 GIGT对妊娠可造成不同程度的危害 ,GIGT是影响孕妇及围生儿结局的重要因素。对妊娠期GIGT均应进行监测和处理  相似文献   
73.
目的研究大剂量生脉注射液对慢性心功能衰竭(简称心衰)患者凝血功能的影响。方法将60例慢性心衰患者随机分为治疗组(即生脉注射液组)和对照组,每组各30例,治疗组给予生脉注射液加西药常规治疗,对照组仅西药常规治疗,观察用药前后心功能改善程度及血浆P-选择素、血管性血友病因子(vWF)和D-二聚体水平的变化。结果治疗组临床显效率与总有效率明显高于对照组。心是患者血浆P-选择素、vWF和D-二聚体水平明显高于健康人,治疗后两组患者血浆P-选择素、vWF和D-二聚体水平均下降,治疗组优于对照组。结论慢性心衰患者,体内存在着高凝状态,大剂量生脉注射液可改善慢性心衰患者的凝血功能,可能在一定程度上减少心衰患者血栓事件的发生和发展?  相似文献   
74.
水面长航舰载保存血液生化指标的实验研究   总被引:1,自引:1,他引:0  
目的探讨和观察经水面长航舰载保存血液出海前后对生化指标的影响与变化。方法随机采集和制备WB、AS-RBC和LP-RBC各18人份(200ml)。每份血液各等分为4袋,配对设计为实验组(A区、B区和C区)与对照组。分别于长航前和长航后进行血液生化指标检测。结果①K+和P3+浓度在三种血液制品的实验组与对照组各观察点的结果均随保存血液时间的延长而增高(P<0.05或P<0.01);Na+浓度由长航前的水平而逐步降低(P<0.01);P3+、Mg2+实验组和对照组较长航前增高,Cl-、Ca2+的含量与长航前没有显著变化;②LDH、AST、CKP和HBDH结果实验组和对照组均呈递增趋势,AKP结果实验组和对照组均呈下降表现,ALT与GGT结果在长航前后变化不明显;③Glu指标减低,UA呈上升趋势。结论长航对血液保存有一定的影响,但总的变化趋势与常规(4±2)℃血库冰箱保存相似。此项研究对于我们进一步探索海上血液保障与运输以及血液海上救护均具有十分重要的实用和军事价值。  相似文献   
75.
胸腰椎压缩性骨折的护理要点   总被引:2,自引:0,他引:2  
胸腰椎压缩性骨折的护理要点福建漳州市中医院(363000)郭燕玲,陈联源我院自1989年来对胸腰椎压缩性骨折实行辨证护理,收到满意效果,介绍如下。常规护理:屈曲型胸腰椎压缩性骨折,令病人仰卧在硬板床上,骨折处垫一软枕头,在耐受的情况下逐渐增加枕头高度...  相似文献   
76.
P1 blood group positivity has been postulated as a host factor which may provide protection against the development of post-enteropathic hemolytic uremic syndrome (HUS). In this study, blood group status in 20 Inuit survivors ofEscherichia coli 0157: H7-associated HUS was compared with age-and sex-matched controls from the same community who had experienced uncomplicated diarrheal illness due to the same pathogen. Of 20 HUS survivors, 6 were P1 antigen positive compared with 8 of the 20 controls (P=0.7). We conclude that P1 antigen positivity was not protective against HUS in this population. Further studies of this condition to clarify the role of host factors in verotoxin-induced endothelial damage are indicated.  相似文献   
77.
Abstract: Prevention of hyperacute rejection is a difficult and unsolved problem in xenotransplantation. Natural antibodies and complement activation have been known to play an important role in the xenotransplantation between discordant species pairs. In the present study, total blood exchange (TBE) was performed with pyridox-alated-hemoglobin-polyoxyethylene conjugate (PHP) solution (Ajinomoto Co., Inc., Kawasaki, Japan) before cardiac xenotransplantation in order to remove the immunoglobulins and prolong xenograft survival time. Guinea pigs and rats were used as the discordant species combination for donor and recipient. Two groups were established: Group 1, untreated control (n = 8) and Group 2, TBT with PHP solution (n = 8). The exchange blood transfusion was carried out at the rate of 15–20 ml/h utilizing PHP solution using a blood pump. After the blood exchange was processed, hematocrit (Ht) levels dropped to 4 or 5%, and a cardiac xenotransplantation was performed within 24 h. The levels of serum IgA, IgM, and IgG were decreased to less than 25, 25, and 10% of the base line, respectively, after blood exchange. A mean xenograft survival time in Group 2 was prolonged to 472 ± 74 min and to 10.4 ± 1.8 min in Group 1 (p < 0.01). A titer of the anti-guinea pig lymphocytotoxic antibody in rat serum was decreased to almost nil. The data from this study suggest that total blood exchange with PHP solution may be useful in preoperative removal of xenograft antibodies in xenotransplantation.  相似文献   
78.
A new, single bolus method of in vivo blood pool imaging using a technetium Tc99m phosphine isocyanide complex (DEPIC) which binds to pre-albumin was evaluated in volunteers (n=4) and patients (n=20). DEPIC was assessed for its safety and possible drug interactions. Its duration of action and quality of ventriculography were compared with imaging using standard in vivo red cell labelling (PYP) during two 3-h scanning periods 1 week apart. DEPIC had a mean plasma halflife of 3.3 h. The count rate over the left ventricle was initially 42% higher with DEPIC than with PYP. However, removal of DEPIC by the liver resulted in equivalent count rates by 1 h, and by 3 h PYP count rates were 22% higher than DEPIC. Immediately post injection mean (SD) difference in the left ventricular ejection fraction between the two methods was 2.4% (7.7%). Satisfactory DEPIC scans were obtained up to 2 h post injection, but by 3 h there was a mean difference of 13% (11.3%). DEPIC was found to be a safe alternative to red all labelling for blood pool angiography, suitable for routine work. The single bolus methodology and high initial count rates offer improved efficiency and a capability for truly emergency scanning.  相似文献   
79.
Test meals with 10.9 g dietary fibre from sugar beet and corresponding control meals were given to eight healthy subjects, aged 67 ± 9 years. The postprandial glucose, triglyceride, hormone and glycerol responses were monitored during 3 hours. After the beet fibre meal the insulin and C-peptide areas were reduced by 28 ( P < 0.01) and 22% ( P > 0.025), respectively, and the somatostatin levels increased by approximately 30% ( P > 0.05). Further, the maximum relative postprandial reduction of plasma glycerol levels was less evident after the fibre-rich meal than after the control meal (36 ± 4% v. 46 ± 4%, P < 0.05). There was no apparent difference in the overall glycaemic response between the meals. The triglyceride levels were similar after both test meals.
Suspension of beet fibre bread given to rats by oro-gastric intubation induced lower blood glucose response than a control bread at 15 and 30 min ( P < 0.001), respectively, but a similar insulin response.
The results suggest an effect of beet fibre on the rate of carbohydrate absorption, expressed as a lower insulin response in the healthy volunteers and a reduced glucose response in the rat.
The mechanism behind this effect in healthy subjects could possibly be mediated by an increased somatostatin response.  相似文献   
80.
目的:探讨新生儿窒息后血糖,血气,心肌酶(谷草转氨酶,磷酸肌酸激酶及乳酸氢酶)的变化及其相关性。方法;血糖采用微量血糖仪测定,血气用足跟动脉化毛细血管法,心肌酶采用酶偶联连续监测,相关分析采用多元线性回归法。结果:低血糖8例,高血糖3例;36例均存在着不同程度的低氧血症和混合性酸中毒;22例心肌酶活性增高。血糖值与日龄呈负相关,与体温呈正相关,心肌酶活性男性高于女性,各酶之间有一定的相关性,但并非  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