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   3460篇
  免费   290篇
  国内免费   60篇
耳鼻咽喉   3篇
儿科学   80篇
妇产科学   201篇
基础医学   205篇
口腔科学   47篇
临床医学   590篇
内科学   273篇
皮肤病学   302篇
神经病学   29篇
特种医学   35篇
外科学   96篇
综合类   702篇
预防医学   879篇
眼科学   71篇
药学   218篇
  4篇
中国医学   67篇
肿瘤学   8篇
  2024年   13篇
  2023年   64篇
  2022年   123篇
  2021年   206篇
  2020年   166篇
  2019年   127篇
  2018年   110篇
  2017年   153篇
  2016年   159篇
  2015年   146篇
  2014年   259篇
  2013年   285篇
  2012年   244篇
  2011年   237篇
  2010年   210篇
  2009年   167篇
  2008年   161篇
  2007年   126篇
  2006年   140篇
  2005年   113篇
  2004年   89篇
  2003年   82篇
  2002年   63篇
  2001年   62篇
  2000年   37篇
  1999年   28篇
  1998年   19篇
  1997年   23篇
  1996年   20篇
  1995年   17篇
  1994年   15篇
  1993年   16篇
  1992年   16篇
  1991年   12篇
  1990年   13篇
  1989年   9篇
  1988年   13篇
  1987年   7篇
  1986年   6篇
  1985年   10篇
  1984年   7篇
  1983年   5篇
  1982年   5篇
  1981年   6篇
  1980年   4篇
  1979年   3篇
  1978年   4篇
  1975年   2篇
  1974年   2篇
  1973年   2篇
排序方式: 共有3810条查询结果,搜索用时 15 毫秒
1.
孕妇血清与初乳中分泌型IgA含量的关系   总被引:1,自引:0,他引:1  
目的探讨孕妇营养与初乳中分泌型免疫球蛋白A(SIgA)含量的关系。方法对101例孕妇作了膳食营养评价,并对其血液营养学指标与产后第3d初乳SIgA含量进行相关分析。结果孕妇血清IgA与初乳SIgA呈明显的正相关(r=0.498P<0.01);血清甘油三酯与初乳SIgA呈明显的负相关(r=-0.338P<0.005);血清叶酸与初乳SIgA呈明显正相关(孕中期r=0.737P<0.001,孕晚期r=0.362P<0.01)相关呈高度显著性。结论初乳SIgA与孕妇个体免疫状态以及孕期代谢状态有关。  相似文献   
2.
Two organ recipients developed serologic evidence of syphilis infection after renal transplantation from a common deceased donor with a history of treated syphilis. Testing of donor serum for syphilis, which occurred after transplantation, gave results interpreted as consistent with past infection. However, subsequent serologic results in the recipients suggested transmission of infection at transplantation due to active infection of the donor. This may be explained by recent donor re-infection in view of the current syphilis epidemic in the United Kingdom. An initial error in the treatment of recipients further served to highlight unfamiliarity in managing this resurgent infection in the context of organ transplantation.  相似文献   
3.
经调查河南省七县1988~04~1989~03孕产妇死亡率为136.1/10万,高于全国平均水平(94.7/10万)。从七县中选择了死亡率偏高的三个县(147.9/10万)为样本.进行厂降低农村孕产妇死亡率保健措施的研究。自1990年4月1日~1992年3月31日。在三县采取了以下保健措施:①加强基层妇幼卫生建设,特别是中心乡卫生院的建设,②整顿和完善三级保健网;③建全孕产妇系统管理制度,高危妊娠筛查,转化和转诊制度,④配备必要设备,建立联合小产院,实行定点接生。两年内孕产妇死亡率,由1989年的147.9/10万下降到67.7/10万,下降幅度为54.44%,最高达72.1%。此工作为实现2000年孕产妇死亡率下降一半的规划目标提供了依据。  相似文献   
4.
A real-time PCR assay with a Taqman probe was developed that targeted the polA gene of Treponema pallidum. The test was validated using an analytical panel (n = 140) and a clinical panel of genital samples (n = 112) from patients attending a sexually transmitted infections clinic. High sensitivities and specificities of 94-100% were achieved using two real-time PCR platforms, the Rotor-Gene and the iCycler. The assay can be completed within 2 h, enabling reporting in <8 h. This fast and robust assay is suitable for implementation in routine laboratories for diagnosing primary syphilis.  相似文献   
5.
Meningovascular syphilis is now quite uncommon, but there have been increasing reports in patients immunocompromised with human immunodeficiency virus. The response of syphilis affecting the central nervous system to antibiotic therapy remains a challenge. This is an even greater challenge in patients who have underlying compromise of the immune system. The authors present a 46-year-old male with recurrent stroke who was found to have cerebrospinal fluid compatible with syphilitic involvement of the central nervous system and a cerebral arteriogram, which revealed focal narrowing of the right middle cerebral artery. The baseline transcranial Doppler study demonstrated increased mean and peak flow velocity within the right middle cerebral artery. Despite a 10-day course of intravenous penicillin, with substantial improvement in the cerebrospinal fluid results, this flow velocity elevation persisted, in a remarkably consistent pattern, over a 4-month follow-up period. Thus, the involved vessel remained patent following treatment, but no clear resolution of the stenotic lesion was observed.  相似文献   
6.
目的了解烟台口岸出入境人群梅毒感染的流行分布状况和趋势,确定重点监测对象,为口岸传染病监测和预防控制提供依据。方法对受检者血清样本采用甲苯胺红不加热血清试验(TRUST)和梅毒螺旋体抗体血凝实验法(TPPA)进行梅毒血清学检测。结果在检测对象中检出的74例梅毒感染者,梅毒感染率为0.20%,男女感染者无显著性差异(P〉0.05),介于21-50岁的中青年感染者构成比为78.39%,入境人员梅毒感染率较往年显著增高。传播途径依然以性传播为主,临床表现不明显,感染以潜伏梅毒居多。结论做好传染病监测的同时,应积极做好性传播疾病的防治宣传工作和咨询工作,加强对远洋船员、劳务人员等高危人群的行为干预,做好入境人员的疾病监测和监管,提高出入境人员的防病意识,降低梅毒感染率。  相似文献   
7.
目的:研究不同孕期阶段(早、中、晚)孕妇凝血四项、血浆纤维蛋白(原)降解产物[plasma fibrin/fibrinogen degradation products, FDP]、D-二聚体的变化及临床意义,为临床诊疗提供理论支持。方法:回顾性分析2021年1月至2021年12月200例孕妇就诊资料中的凝血四项,纤维蛋白原(fibrinogen, FIB)、凝血酶原时间(prothrombin time, PT)、凝血酶时间(thrombin time, TT)、活化部分凝血活酶时间(activated partial thromboplastin time, APTT)。并对FDP与D-二聚体的检测结果进行统计分析,比较孕早期、中期、晚期三个阶段凝血四项、FDP和D-二聚体水平的变化。结果:孕早期、孕中期与孕晚期PT水平比较,差异有统计学意义(P<0.05);孕早期、孕中期与孕晚期三个阶段的TT相比,差异无统计学意义(P>0.05);孕早期的APTT明显长于中期、晚期孕妇,差异有统计学意义(P<0.05);孕早期、中期、晚期孕妇,随着孕周的增加,FIB水平逐渐升高...  相似文献   
8.
In this 2 × 2 factorial, outcome-assessor blinded, feasibility randomised trial we explored the effect of a non-pharmaceutical multi-component intervention on periodontal health and metabolic and inflammatory profiles among pregnant women with periodontitis receiving prenatal care in a Brazilian public health centre. 69 pregnant women (gestational age ≤20 weeks, T0) were randomly allocated into four groups: (1) fortified sachet (vitamin D and calcium) and powdered milk plus periodontal therapy during pregnancy (early PT) (n = 17); (2) placebo sachet and powdered milk plus early PT (n = 15); (3) fortified sachet and powdered milk plus late PT (after delivery) (n = 19); (4) placebo sachet and powdered milk plus late PT (n = 18). Third trimester (T1) and 6–8 weeks postpartum (T2) exploratory outcomes included periodontal health (% sites with bleeding on probing (BOP)), glucose, insulin, C-Reactive Protein, serum calcium and vitamin D. The mean BOP was significantly reduced in the early PT groups, while BOP worsened in the late PT groups. No significant effect of fortification on BOP was observed. Changes in glucose levels and variation on birthweight did not differ among groups This feasibility trial provides preliminary evidence for estimating the minimum clinically important differences for selected maternal outcomes. A large-scale trial to evaluate the interventions’ clinical benefits and cost-effectiveness is warranted.  相似文献   
9.
Objective: The purpose of this study was to evaluate serum zinc status of pregnant women in the China Adult Chronic Disease and Nutrition Surveillance (CACDNS) in 2015–2016. Methods: A total of 7147 apparently healthy pregnant women were randomly selected in 302 national monitoring sites. Information on age, race, residence region, education, pregnancy, and family income per annum was collected, and the concentration of serum zinc was determined. The evaluation of serum zinc status was further performed according to the recommendations by the International Zinc Nutrition Consultative Group (IZiNCG). Results: The median concentration of serum zinc was 858.9 μg/L with an interquartile range (IQR) of 712.9 μg/L and 1048.9 μg/L, while the overall prevalence of zinc deficiency was 3.5% with a 95% confidence interval (CI) of 3.0% and 3.9%. Serum zinc status of pregnant women changed greatly in the different categories, particular in pregnancy and family income per annum (p < 0.05), but no significant difference was observed in the prevalence of zinc deficiency (p > 0.05). Conclusions: The lower prevalence of zinc deficiency generally indicated a better zinc status for pregnant women in the CACDNS in 2015–2016. However, a well-designed evaluation system of zinc status for pregnant women should be continually optimized and improved by inducing more parameters such as biochemical, dietary, or functional indicators.  相似文献   
10.
目的 探讨孕妇弓形虫感染对妊娠的影响。方法 采用酶联免疫吸附试验三联诊断法对 35 6例孕妇及其新生儿进行血清弓形虫抗原及抗体检测。结果 孕妇弓形虫感染率平均为 15 .17% ,不同年龄组孕妇感染率无显著性差异 ,但高龄产妇组略高 ;不同职业孕妇感染率无显著差别 ,但农民组感染率明显较高。 4例畸形儿中弓形虫感染阳性 2例。有早产史的孕妇弓形虫阳性率为 2 0 % ,明显高于平均感染率。此外还发现第 2胎怀孕出生的新生儿其循环抗原阳性率为 42 .86 % ,显著高于第 1胎出生者 (19.15 % )。结论 孕妇弓形虫感染可引起早产、畸胎 ,对新生儿有一定影响  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