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   8514篇
  免费   825篇
  国内免费   64篇
耳鼻咽喉   14篇
儿科学   1427篇
妇产科学   2429篇
基础医学   685篇
口腔科学   125篇
临床医学   644篇
内科学   385篇
皮肤病学   21篇
神经病学   285篇
特种医学   41篇
外科学   249篇
综合类   700篇
一般理论   3篇
预防医学   1841篇
眼科学   61篇
药学   317篇
  3篇
中国医学   38篇
肿瘤学   135篇
  2024年   25篇
  2023年   180篇
  2022年   271篇
  2021年   393篇
  2020年   366篇
  2019年   412篇
  2018年   393篇
  2017年   454篇
  2016年   411篇
  2015年   367篇
  2014年   574篇
  2013年   761篇
  2012年   428篇
  2011年   527篇
  2010年   437篇
  2009年   439篇
  2008年   407篇
  2007年   399篇
  2006年   342篇
  2005年   290篇
  2004年   243篇
  2003年   209篇
  2002年   142篇
  2001年   97篇
  2000年   100篇
  1999年   76篇
  1998年   51篇
  1997年   58篇
  1996年   44篇
  1995年   47篇
  1994年   40篇
  1993年   48篇
  1992年   30篇
  1991年   34篇
  1990年   27篇
  1989年   23篇
  1988年   30篇
  1987年   19篇
  1986年   24篇
  1985年   25篇
  1984年   30篇
  1983年   15篇
  1982年   21篇
  1981年   16篇
  1980年   17篇
  1979年   9篇
  1978年   9篇
  1977年   12篇
  1976年   9篇
  1975年   7篇
排序方式: 共有9403条查询结果,搜索用时 906 毫秒
41.
目的探讨极低出生儿体重儿转运过程中的有效护理措施,降低其死亡率。方法通过转运系统将基层医院32例极低出生体重儿转运至新生儿重症监护病房治疗,具体措施包括现场抢救,应用肺泡表面活性物质,途中连续监护和治疗。结果极低出生体重儿32例均成功转运,治愈出院13例,死亡19例,无一例途中死亡。结论全程监护,尽早转运及应用固尔苏是转运成功及降低极低出生体重儿死亡率的关键。  相似文献   
42.
目的:探讨产道血肿形成的病因,临床处理及预后。方法:选取2001年8月至2006年8月阴道分娩的4000例产妇,其中25例发生产道血肿,对其进行回顾性分析,通过分析其病因,临床处理及转归,对该病的预防,诊治经验和教训进行总结评价。结果:产道血肿的发生率为0.625%,经过积极有效的处理,25例发生产道血肿的产妇均痊愈。结论:分娩过程中,应仔细询问产妇病史,对存在有可能发生出血倾向的高危孕妇应严密观察,争取做到早发现;而已发生血肿的产妇,应针对不同病因早治疗,以改善产妇的预后。  相似文献   
43.
背景 育龄期女性胚胎着床失败及流产的最常见原因是胚胎异常,但移植经胚胎种植前遗传学检测(PGT)筛选后的正常胚胎后,仍出现种植失败或流产的原因目前并没有形成统一的结论。目的 分析PGT助孕后种植失败及流产的影响因素。方法 回顾性分析2018年12月至2021年2月在安徽医科大学第一附属医院生殖中心行PGT助孕的329例患者的临床资料,根据患者是否临床妊娠分为临床妊娠组(n=218)和种植失败组(n=111),并将临床妊娠组患者根据妊娠结局分为活产亚组(n=175)和流产亚组(n=43)。比较临床妊娠组和种植失败组,活产亚组和流产亚组的一般情况、促排卵及体外胚胎发育情况。采用多因素Logistic回归分析探讨PGT患者种植失败及流产的影响因素。绘制受试者工作特征(ROC)曲线分析多因素Logistic回归分析筛选出的影响因素对PGT患者发生种植失败及流产的预测价值。结果 多因素Logistic回归分析显示,既往流产次数≥2次〔OR=4.032 0,95%CI(2.423 0,6.710 0)〕、高密度脂蛋白胆固醇(HDL-C)水平低〔OR=3.890 0,95%CI(1.455 0,10...  相似文献   
44.
近存活期分娩(PVB)儿各组织系统发育极不成熟,易发生各种器官功能损害和并发症,预后常不佳。目前关于PVB儿出生后早期管理的报道不多,诸多尚待解决的问题仍是围产医学所面临的挑战。经有效的新生儿复苏和呼吸循环支持、积极的营养支持和喂养、防治感染、内分泌和代谢性疾病管理、积极处理早产儿相关并发症,以及发育支持护理、家庭参与式护理等一系列个体化管理和精细化护理,四川省医学科学院·四川省人民医院成功救治了1例胎龄23周,出生体质量(BW)为450 g的PVB儿。本文通过总结1例PVB儿的出生后早期管理,并结合文献复习进行归纳总结,以期为提高BW<500 g的PVB儿存活率并获得良好预后提供经验及借鉴。  相似文献   
45.
In a twin sample where duration of gestation can be controlled, a specific example of the fetal origins hypothesis concerning association between low birth weight and early age at menopause is explored. The hypothesis is based on the physiologically plausible path from intrauterine growth retardation and reduced numbers of primary follicles to an earlier menopause. The sample comprised 323 Australian female twin pairs where both co-twins had reached menopause naturally and reported on their weight at birth. Regression analysis showed no linear association between the two variables (P = 0.371, r(2) = 0.0009). Intra-pair differences in age at menopause were investigated in the context of relative birth weight of co-twins. In 265 pairs an intra-pair birth weight difference was reported. In monozygotic (MZ) pairs (n = 168) this allowed for control of genetic effects as well as gestation duration. No significant differences dependent on birth weight relative to co-twin were found for age at natural menopause in either MZ or dizygotic (DZ) twin pairs, even in pairs whose birth weights differed markedly. There was some indication that twins with premature ovarian failure were heavier at birth than twins with normal or later menopausal age. We conclude that the hypothesis that lower birth weight is associated with earlier menopause is not supported by our data.  相似文献   
46.
We present a girl with mild manifestations of the Brachmann-de Lange syndrome (BDLS) with gradual change of the phenotype. Her findings support the hypothosis of variability of the phenotypic spectrum of the disorder.  相似文献   
47.

Objective

This study investigated how health care provider communication of risk information, and women’s role in decision-making, influenced women’s preferences for mode of birth after a previous caesarean birth.

Methods

Women (N?=?669) were randomised to one of eight conditions in a 2 (selectivity of risk information) × 2 (format of risk information) × 2 (role in decision making) experimental design. After exposure to a hypothetical decision scenario that varied information communicated by an obstetrician to a pregnant woman with a previous caesarean birth across the three factors, women were asked to decide their preferred hypothetical childbirth preference.

Results

Women provided with selective information (incomplete/biased toward repeat caesarean) and relative risk formats (ratio of incidence being compared e.g. 2.5 times higher), perceived lower risk for caesarean and were significantly more likely to prefer repeat caesarean birth than those provided with non-selective information (complete/unbiased) and absolute risk formats (incidence rate e.g. 0.01 per 100). Role in decision-making did not significantly influence childbirth preferences

Conclusions

Modifiable aspects of healthcare provider communication may influence women’s decision-making about childbirth preferences

Practice implications

Optimised communication about risks of all options may have an impact on over-use of repeat CS.  相似文献   
48.
Data on the occurrence of neural tube defects in first-, second-, and third-degree relatives of probands were collected in a United States study. The proportions of affected individuals were 3.2%, 0.5%, and 0.17% respectively. These findings are compared to those from other recent North American studies, and differences are discussed. It is pointed out that accurate recurrence risk figures may not be available, and that caution should be used when counseling families with relatives who are affected with NTD.  相似文献   
49.
目的探讨我院2006年334例早产儿,分析发生的危险因素,以总结提高产科早产预防、医疗水平,并提供研究参考。方法早产组334例与同期分娩的足月对照组334例分析比较,早产的临床相关因素及对围产儿的影响。结果胎膜早破,妊娠高血压综合征,前置胎盘,臀位,多胎妊娠是早产的重要因素。早产使新生儿窒息,围生儿死亡,低体重儿增加。结论早产使围产儿窒息和死亡率增加。加强早产预测可望降低早产的发生,提高围生医学质量。  相似文献   
50.
BACKGROUND: We recently found that paracetamol (acetaminophen) use in late pregnancy was associated with an increased risk of early wheezing in the offspring. OBJECTIVE: To see whether use of paracetamol in late pregnancy is associated with an increased risk of asthma, wheezing and other atopic outcomes in the child at school age. METHODS: In the population-based Avon Longitudinal Study of Parents and Children, we measured associations of paracetamol and aspirin use in late pregnancy (20-32 weeks) with asthma, hayfever, eczema (n = 8511) and wheezing (8381) in the offspring at 69-81 months, and with atopy (positive skin prick test to Dermatophagoides pteronyssinus, cat or grass, n = 6527) and blood total IgE (n = 5148) at 7 years. We used logistic and linear regression to analyse binary outcomes and log-transformed IgE, respectively, controlling for potential confounders. RESULTS: Use of paracetamol, but not aspirin, in late pregnancy was positively associated with asthma (odds ratios (ORs), comparing children whose mothers took paracetamol 'sometimes' and 'most days/daily' with those whose mothers never took it, 1.22 (95% confidence interval (CI): 1.06-1.41) and 1.62 (95% CI: 0.86-3.04), respectively; P trend = 0.0037), wheezing (ORs 1.20 (95% CI: 1.02-1.40) and 1.86 (95% CI: 0.98-3.55), respectively; P trend = 0.011), and total IgE (geometric mean ratios 1.14 (95% CI: 1.03-1.26) and 1.52 (95% CI: 0.98-2.38), respectively; P trend = 0.0034), but not hayfever, eczema or skin test positivity. The proportion of asthma attributable to paracetamol use in late pregnancy, assuming a causal relation, was 7%. CONCLUSION: Paracetamol exposure in late gestation may cause asthma, wheezing and elevated IgE in children of school age.  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