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   140169篇
  免费   7763篇
  国内免费   2701篇
耳鼻咽喉   580篇
儿科学   2580篇
妇产科学   1515篇
基础医学   14318篇
口腔科学   3939篇
临床医学   16115篇
内科学   24343篇
皮肤病学   1741篇
神经病学   9014篇
特种医学   4647篇
外国民族医学   5篇
外科学   18088篇
综合类   17397篇
现状与发展   7篇
一般理论   5篇
预防医学   9647篇
眼科学   1904篇
药学   11231篇
  95篇
中国医学   9899篇
肿瘤学   3563篇
  2023年   1523篇
  2022年   2096篇
  2021年   4721篇
  2020年   3804篇
  2019年   7207篇
  2018年   7421篇
  2017年   5663篇
  2016年   3362篇
  2015年   3321篇
  2014年   6261篇
  2013年   6730篇
  2012年   5456篇
  2011年   5932篇
  2010年   4854篇
  2009年   4186篇
  2008年   4327篇
  2007年   4487篇
  2006年   4049篇
  2005年   3632篇
  2004年   3174篇
  2003年   2990篇
  2002年   2557篇
  2001年   2514篇
  2000年   2057篇
  1999年   1836篇
  1998年   1529篇
  1997年   1636篇
  1996年   1322篇
  1995年   1338篇
  1994年   1225篇
  1993年   941篇
  1992年   925篇
  1991年   829篇
  1990年   656篇
  1989年   631篇
  1988年   613篇
  1987年   521篇
  1985年   3414篇
  1984年   3863篇
  1983年   3171篇
  1982年   3764篇
  1981年   3349篇
  1980年   2803篇
  1979年   2718篇
  1978年   2247篇
  1977年   1697篇
  1976年   2143篇
  1975年   1588篇
  1974年   1381篇
  1973年   1320篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
31.
目的探讨早期使用十全大补汤联合肠内营养乳剂(TP)治疗胃癌术后(气血两虚证)发生喂养不耐受(FI)的影响因素及对营养指标、中医证候积分的影响。方法回顾性分析术后早期行十全大补汤联合TP治疗的80例胃癌术后(气血两虚)患者的病历资料,根据是否出现FI分为耐受组(34例)和不耐受组(46例)。FI的相关影响因素进行单因素及多因素分析,并观察FI对患者营养指标、中医证候积分的影响。结果单因素分析显示,患者术后第1天下床活动时间、开始肠内营养(EN)的时间、使用营养泵、早期灌肠与FI的发生密切相关(P <0. 05);多因素Logistic回归分析显示,患者第1天下床活动时间≥2 h[OR=0. 022,P=0. 001,95%CI(0. 002,0. 223)]、使用营养泵[OR=0. 021,P=0. 000,95%CI(0. 003,0. 162)]是FI发生的独立危险因素;术后10 d,耐受组患者白蛋白(ALB)、血红蛋白(Hb)升高水平优于不耐受组(P <0. 05),中医证候积分显著低于不耐受组(P <0. 05)。结论胃癌术后(气血两虚证)患者早期给予十全大补汤联合TP治疗开始后,患者第1天下床活动时间不短于2 h、使用营养泵能有效减少FI的发生,并改善了患者的营养状态,减轻了中医临床症状。  相似文献   
32.
王晓莉  刘燕  何振娟  陈超 《安徽医药》2016,37(10):1204-1207
目的 通过观察早产儿不同胎龄Toll样受体9(TLR9)的表达,探讨早产儿免疫功能低下的机制。方法 采集2010年7月至2014年6月在上海市嘉定区妇幼保健院产科出生的活产新生儿的脐血229份,按胎龄分为4组,28~31周组,31~34周组,34~37周组,≥37周组,采用流式细胞术和实时荧光定量PCR方法,分别检测其TLR9的蛋白和mRNA表达情况,了解其与胎龄之间的关系,并分析mRNA和蛋白表达间的相关性。结果 TLR9阳性细胞率在28~31周组,31~34周组,34~37周组,≥37周组分别为(15.93±6.23)%,(11.63±6.70)%,(13.66±6.88)%,(20.51±12.06)%;其在胎龄28~31周较高,至31~34周逐渐下降至最低,两组差异有统计学意义(P<0.05);34~37周后TLR9阳性细胞率表达逐渐升高,至≥37周达最高,两胎龄组比较,差异具有统计学意义(P<0.05)。31~37周间新生儿脐血TLR9阳性细胞率与胎龄呈正相关(r=0.273,P=0.006)。TLR9 mRNA表达在28~31周组,31~34周组,34~37周组,≥37周组分别为(4.95±3.44)%,(8.89±8.49)%,(13.91±10.92)%,(7.19±7.11)%;其在28~36周逐渐升高,与胎龄呈正相关(r=0.355,P< 0.001)。≥37周TLR9 mRNA表达量下降,该值虽高于28~31周,但差异无统计学意义(P>0.05)。相关性分析表明,同胎龄时期同样本新生儿的TLR9 mRNA和TLR9阳性细胞率之间存在负相关(r=-0.227,P=0.011)。结论 TLR9阳性细胞率和TLR9 mRNA表达在不同胎龄组新生儿间有差异,TLR9阳性细胞率表达在31~37周间随着胎龄的增加而增加,TLR9 mRNA在28~36周间随着胎龄的增加而增加。  相似文献   
33.
Shouwen Zhang  Jie Wang 《Drug delivery》2016,23(9):3696-3703
Context: Baicalin has many pharmacological activities, including protective function against myocardial ischemia by antioxidant effects and free radical scavenging activity. However, its rapid elimination half-life in plasma and poor water solubility limits its clinical efficacy.

Objective: Novel baicalin-loaded PEGylated nanostructured lipid carriers (BN-PEG-NLC) were developed to improve bioavailability of BN, to prolong retention time in vivo and to enhance its protective effect.

Methods: In this study, BN-PEG-NLC were prepared by the emulsion-evaporation and low temperature-solidification method using a mixture of glycerol monostearate and polyethylene glycol monostearate as solid lipids, and oleic acid as the liquid lipid. The physicochemical properties of NLC were characterized. The pharmacokinetic and pharmacodynamic behaviors of BN-PEG-NLC or BN-NLC were evaluated in acute MI rats.

Results and discussion: The particle size, zeta potential, and entrapment efficiency for BN-PEG-NLC were observed as 83.9?nm, ?32.1?mV, and 83.5%, respectively. The release profiles of BN from both BN-PEG-NLC and BN-NLC were fitted to the Ritger–Peppas modal, which presented burst release initially and prolonged release afterwards. Pharmacokinetics results indicated that BN-PEG-NLC exhibited a 7.2-fold increase in AUC in comparison to BN solution, while a 3-fold increase in comparison to BN-NLC. Biodistribution results revealed that BN-PEG-NLC exhibited higher heart drug concentration compared with BN-NLC as well as BN solution. In the present study, BN-PEG-NLC significantly ameliorated infarct size.

Conclusion: The results of the present study imply that PEG-NLC could be the biocompatible carriers for heart-targeted drug delivery to improve myocardial ischemia.  相似文献   
34.
《Vaccine》2016,34(43):5155-5158
BackgroundGrowing conflict and insecurity played a major role in precipitating polio outbreaks in the Horn of Africa and the Middle East. In Angola, the early post-conflict situation was characterized by the presence of many inaccessible zones and districts due to insecurity and poor infrastructure. Partnership with the Angolan Army health service (AAHS) was one of the innovative strategies that the Polio Eradication Initiative (PEI) introduced into the country to support the polio vaccination campaigns in insecure and hard to reach zones.MethodsBefore embarking on creating a partnership with Angolan military it was essential to make high-level advocacy with top military decision makers to engage the leadership in the process for better and sustainable support to the strategy. The principal supports provided by the AAHS were the administration of oral polio vaccine, vitamin A, deworming agents, social mobilization, monitoring campaign quality, and surveillance. Distribution of logistics using military vehicles and helicopters to hard to reach and insecure zones was also part of the support.ResultsUsing this partnership it was possible to reach a significant number of children in insecure and hard to reach areas with polio vaccine and other child survival interventions. The military partnership also contributed in increasing the demand and addressing rejection for the polio vaccine.ConclusionMilitary is a potentially productive force that can be used for any development activities in any country. The Angolan experience has demonstrated that it is possible to form a partnership with the military for basic health intervention activities with little training and investment.  相似文献   
35.

Background

Arterial vascular anomalies in patients undergoing kidney transplantation (KT) are correlated with a higher incidence of early surgical complications, potentially causing graft loss. Arterial reconstruction allows patients to overcome these surgical challenges, thus minimizing the risk of poor outcomes. The aim of the present study is to retrospectively investigate the safety and effectiveness of the multiple arterial reconstruction technique with a Teflon patch in case of an unavailable aortic patch: to do so, surgical complications, graft function, and patient survival were evaluated.

Methods

During the period January 2009 to August 2016, 202 adult deceased-donor KTs were performed at our center. Group A (n = 27; reconstruction of multiple arteries) and Group B (n = 175; control group) were compared.

Results

No differences were observed between the 2 groups in terms of early postoperative course, with no vascular complication observed in Group A. No vascular patch infections were reported, nor longer cold ischemia time rates. Similarly, long-term survival rates were similar between the 2 groups.

Conclusions

The Teflon-patch arterial reconstruction technique appears to be safe and effective, with an acceptable balance of benefits and potential risks of using a prosthetic material. Studies based on larger series are needed to further validate this approach.  相似文献   
36.
37.
38.
39.
40.
目的:探讨益气通脉饮治疗气虚血瘀型冠心病心绞痛的临床疗效。方法:选取2017年10月—2019年2月烟台业达医院收治的气虚血瘀型冠心病心绞痛的患者90例作为研究对象,根据随机数字表法将所选患者均分为两组,每组各45例,两组的一般资料经统计学方法,差异无统计学意义(P>0.05),因此具有可比性。对照组给予常规西药进行治疗,观察组在对照组治疗基础上给予益气通脉饮治疗,1个月后比较两组临床的疗效,评估治疗前后中医证候、心绞痛症状分级和血脂水平。临床检测的数据通过统计产品与服务解决方案(Statistical Product and Service Solutions,SPSS) 19.0软件进行分析和处理,计量的数据使用平均数±标准差(x±s)表示,采用双侧t检验,计数的数据采用χ~2检验,以%表示,以P<0.05为差异有统计学意义。结果:治疗后,对照组和观察组都有一定疗效,但观察组的改善中医证候总有效率95.56%(43/45),高于对照组的82.22%(37/45),两组比较具有统计学意义(P<0.05);心绞痛的症状总有效率观察组为93.33%(42/45),对照组为77.78%(35/45),两组比较差异有统计学意义(P<0.05);与治疗前相比较,两组治疗后的三酰甘油(Triglyceride,TG)、血清总胆固醇(Serum Total Cholesterol,TC)、高密度脂蛋白胆固醇(High Density Liptein Cholesterol,HDL-C)水平均降低(P<0.05),且观察组治疗后低于对照组(P<0.05),两组治疗后的HDL-C升高(P<0.05),组间比较,差异无统计学意义(P>0.05)。结论:益气通脉饮治疗气虚血瘀型冠心病心绞痛的疗效显著,值得临床进一步研究与推广应用。  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