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   28870篇
  免费   1778篇
  国内免费   370篇
耳鼻咽喉   25篇
儿科学   616篇
妇产科学   7452篇
基础医学   3152篇
口腔科学   190篇
临床医学   3209篇
内科学   2071篇
皮肤病学   250篇
神经病学   503篇
特种医学   357篇
外国民族医学   2篇
外科学   1067篇
综合类   4814篇
现状与发展   3篇
一般理论   4篇
预防医学   4182篇
眼科学   69篇
药学   2278篇
  43篇
中国医学   468篇
肿瘤学   263篇
  2024年   63篇
  2023年   395篇
  2022年   797篇
  2021年   1154篇
  2020年   1056篇
  2019年   1044篇
  2018年   951篇
  2017年   1137篇
  2016年   1281篇
  2015年   1078篇
  2014年   1849篇
  2013年   2716篇
  2012年   1563篇
  2011年   1869篇
  2010年   1509篇
  2009年   1312篇
  2008年   1277篇
  2007年   1216篇
  2006年   1244篇
  2005年   1029篇
  2004年   927篇
  2003年   746篇
  2002年   566篇
  2001年   516篇
  2000年   419篇
  1999年   398篇
  1998年   293篇
  1997年   268篇
  1996年   259篇
  1995年   305篇
  1994年   198篇
  1993年   172篇
  1992年   139篇
  1991年   133篇
  1990年   123篇
  1989年   109篇
  1988年   113篇
  1987年   75篇
  1986年   72篇
  1985年   128篇
  1984年   98篇
  1983年   80篇
  1982年   73篇
  1981年   45篇
  1980年   60篇
  1979年   45篇
  1978年   31篇
  1977年   22篇
  1976年   21篇
  1973年   12篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
目的:探讨妊娠早期血清学指标糖化血红蛋白(glycohemoglobin,HbA1c)联合妊娠相关血浆蛋白A(pregnancy-associated plasma protein A,PAPP-A)对妊娠期糖尿病(gestational diabetes mellitus,GDM)的预测意义。方法:随机选取2018年12月1日-2019年7月30日孕11~13+6周于我院门诊产检的妊娠妇女,进行临床资料采集并记录妊娠早期(11~13+6周)空腹血糖(fasting plasma glucose,FPG)、HbA1c、PAPP-A中位数倍数(multiple of the median,MoM)水平,根据孕24~28周进行的75 g口服葡萄糖耐量试验(oral glucose tolerance test,OGTT)结果将研究对象分为研究组和对照组,统计分析妊娠早期血清学指标预测GDM的最佳截断值并得出最适宜的联合预测方案。结果:多因素Logistic回归分析显示,高水平FPG和HbA1c、低水平PAPP-A、受孕方式采用辅助生殖技术、有家族糖尿病史以及妊娠早期体质量指数(BMI)为超重或肥胖均是GDM发生的独立危险因素。有糖尿病家族史和使用辅助生殖技术受孕发生GDM的风险显著增高(OR分别为7.206和47.512,均P<0.001)。分析不同预测指标的受试者工作特征(receiver operating characteristic,ROC)曲线及曲线下面积(area under the curve,AUC)显示,PAPP-A MoM联合HbA1c及FPG诊断时AUC最大(0.728),其后依次为PAPPA MoM联合HbA1c(0.721)、HbA1c联合FPG(0.717),均大于HbA1c(0.707)和FPG(0.647),而PAPP-A MoM的AUC为0.380,对GDM没有诊断意义。结论:具有高风险因素的孕妇,推荐在妊娠早期联合检测HbA1c与PAPPA MoM,以早期预测GDM。  相似文献   
2.
Bernard–Soulier syndrome (BSS) is a rare autosomal recessively inherited bleeding disorder. Pregnancy in patients with BSS is characterized by ante‐, intra‐, or postpartum haemorrhage, which may be delayed and severe. There is no consensus in the management of BSS in pregnancy and so far only 16 pregnancies in nine patients have been described. We report a further three pregnancies in two women with the syndrome. We also outline our management of pregnant patients with BSS.  相似文献   
3.
This paper reports the changes in prolactin levels after 12 spontaneous and 52 induced pregnancies in 54 women with unambiguous hyperprolactinaemia (median plasma prolactin levels 67.5 ng/ml, range 40-400). Twenty-three of the patients showed radiological evidence of prolactinoma. The pregnancies were induced in 37 patients by bromocriptine, in nine by metergoline, in two by lisuride and in four by other treatments. Of the 64 pregnancies, 16 ended in spontaneous abortion, while 48 went to term. Follow-up was continued for at least 6 months after delivery or until the end of lactation. In a control group of 32 hyperprolactinaemic women (median prolactin 70 ng/ml, range 40-400) not wishing to become pregnant, prolactin changes were similarly registered over a mean period of 15 months without any treatment (range 6-38 months). After pregnancy, a significant downward trend of plasma prolactin was observed in the puerperal women with a 'normalization' rate of 17%. No changes were observed in the 32 controls who did not become pregnant.  相似文献   
4.
特殊部位异位妊娠的临床分析   总被引:1,自引:0,他引:1  
目的探讨特殊部位异位妊娠的临床特点,误诊原因及治疗原则。方法对1996年1月至2003年12月诊治的256例特殊部位异位妊娠进行回顾性分析。结果特殊部位异位妊娠发生率占同期异位妊娠的3.36%,术前诊断率48.4%,所有的患者均行手术。视术中情况进行不同的处理,所得标本均经病理切片证实,全部患者愈后良好。结论特殊部位异位妊娠的临床表现不典型,容易漏诊误诊,一旦怀疑本病应尽早住院,及时明确诊断并手术,患者愈后良好。  相似文献   
5.
异位妊娠的腹腔镜手术临床分析   总被引:4,自引:0,他引:4  
目的探讨电视腹腔镜手术治疗内出血异位妊娠的安全性和可行性。方法回顾分析2000年8月 ̄2004年8月该院电视腹腔镜手术治疗的15例伴有内出血的异位妊娠(出血量大于800mL,观察组)及同期30例无明显内出血异位妊娠病人的临床资料(对照组)。结果15例病人均手术成功,无中转开腹及并发症发生,两组手术时间及手术后住院时间均无明显差异。结论随着腹腔镜手术操作技巧、麻醉和监护技术的提高,腹腔镜手术治疗内出血甚至休克型异位妊娠在一定条件下是安全可行的。  相似文献   
6.
7.
AIMS: In normotensive women with Type 1 diabetes and microalbuminuria we previously found preterm delivery (< 34 weeks) in 23% of the pregnancies. Antihypertensive treatment was initiated in late pregnancy when preeclampsia was diagnosed and diastolic blood pressure > 90 mmHg. From April 2000 our routine was changed and early antihypertensive treatment with methyldopa was initiated if antihypertensive treatment was given prior to pregnancy, if urinary albumin excretion (UAE) was > 2 g/24 h, or blood pressure > 140/90 mmHg. The present study describes the impact of this more aggressive antiypertensive treatment in the prevalence of preterm delivery. METHODS: The old cohort (1995-1999) consisted of 26 and the new cohort (2000-2003) of 20 pregnant women with Type 1 diabetes and microalbuminuria. All were referred before gestational week 17. RESULTS: The cohorts were comparable with regard to age, diabetes duration, prepregnancy body mass index, HbA1c, blood pressure 121 (13)/71 (8) vs. 121 (14)/73 (8) mmHg [mean (sd)] and early UAE 69 (16-278) vs. 74 (30-287) mg/24 h (geometric mean and range). Antihypertensive treatment was initiated in the old cohort at 29 (20-33) weeks, n = 9, and in the new at 13 (0-34) weeks, n = 10. The prevalence of preterm delivery before 34 weeks was reduced from 23% to zero (P = 0.02), preterm delivery before 37 weeks from 62% to 40% (P = 0.15) and preeclampsia from 42% to 20% (P = 0.11). Perinatal mortality occurred in 4% vs. 0%. Birth weight was 3124 (767) g vs. 3279 (663) g. CONCLUSION: Introduction of early antihypertensive treatment with methyldopa in normotensive pregnant women with Type 1 diabetes and microalbuminuria resulted in a significant reduction in preterm delivery before gestational week 34.  相似文献   
8.
易湘鄂 《中外医疗》2009,28(31):57-58
目的探讨异位妊娠的诊断和治疗方法。方法对32例来本院就诊的异位妊娠患者进行回顾性分析。结果异位妊娠患者超声下表现多样,32例中保守治疗成功率96.9%。1例改行手术成功。结论异位妊娠的症状变化多样,病情凶险,应早期诊断,积极治疗。  相似文献   
9.
胡孟钩 《河北医学》1998,4(1):22-23
应用临床病理资料资料对27例卵巢异位妊娠加以分析、探讨其临床病理特点是其影响因素,结果表明输卵管炎症及宫内节育环可促发卵巢妊娠的发生。  相似文献   
10.
The state of pregnancy is an immunological enigma during which the body must prevent rejection of the antigenically foreign fetus while at the same time maintain sufficient maternal host defense mechanisms to combat infection. Although most studies on the immunology of pregnancy focus on immune suppression, several studies have shown an increase in nonspecific host defense, which is postulated to be a compensatory mechanism for decreased specific immunity during pregnancy. Studies in this laboratory have shown that monocyte surface FcγRI (CD64) and FcγRII (CD32) expression progressively increase throughout pregnancy, while surface MHC class II expression remains unchanged. Functional studies revealed that the number of phagocytic monocytes which could be isolated from pregnant women was increased. These cells exhibited an increased capacity to ingest IgG-opsonized human erythrocytes. This study shows for the first time that monocyte surface FcγR expression and FcγR-mediated functions are increased during pregnancy. These results support the hypothesis that nonspecific immunity as represented by FcγR expression and function is increased during pregnancy.  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