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   6286篇
  免费   400篇
  国内免费   105篇
耳鼻咽喉   80篇
儿科学   1922篇
妇产科学   603篇
基础医学   385篇
口腔科学   10篇
临床医学   768篇
内科学   400篇
皮肤病学   32篇
神经病学   122篇
特种医学   103篇
外科学   215篇
综合类   1043篇
预防医学   605篇
眼科学   45篇
药学   361篇
  13篇
中国医学   66篇
肿瘤学   18篇
  2023年   66篇
  2022年   121篇
  2021年   195篇
  2020年   183篇
  2019年   178篇
  2018年   140篇
  2017年   153篇
  2016年   211篇
  2015年   182篇
  2014年   355篇
  2013年   427篇
  2012年   345篇
  2011年   393篇
  2010年   278篇
  2009年   277篇
  2008年   266篇
  2007年   293篇
  2006年   338篇
  2005年   328篇
  2004年   263篇
  2003年   186篇
  2002年   155篇
  2001年   155篇
  2000年   123篇
  1999年   117篇
  1998年   96篇
  1997年   85篇
  1996年   82篇
  1995年   87篇
  1994年   68篇
  1993年   53篇
  1992年   34篇
  1991年   31篇
  1990年   46篇
  1989年   44篇
  1988年   48篇
  1987年   32篇
  1986年   28篇
  1985年   35篇
  1984年   33篇
  1983年   27篇
  1982年   39篇
  1981年   30篇
  1980年   24篇
  1979年   22篇
  1978年   14篇
  1977年   21篇
  1976年   16篇
  1973年   12篇
  1972年   15篇
排序方式: 共有6791条查询结果,搜索用时 93 毫秒
1.
目的 探讨血清微小RNA-210(mircoRNA-210,miR-210)与新生儿呼吸窘迫综合征(neonatalrespiratory distress syndrome,NRDS)严重程度和预后的关系。 方法 收集NRDS患儿104例,根据预后分为生存组与死亡组。所有新生儿根据首次胸部X线片结果与病情严重程度分为轻度组(Ⅰ级、Ⅱ级)与重度组(Ⅲ级、Ⅳ级)。比较死亡组与生存组患儿一般资料,轻度组与重度组血清miR-210水平与新生儿急性生理学评分围生期补充Ⅱ(perinatal supplement of acute physiological score for neonates Ⅱ,SNAPPE-Ⅱ)评分。绘制ROC曲线分析血清miR-210水平对NRDS患儿死亡的预测价值。采用Spearman相关性分析NRDS发生与血清miR-210的相关性。 结果 根据预后分组,104例患儿中预后较好81例(77.88%),死亡23例(22.12%)。生存组miR-210水平、SNAPPE-Ⅱ评分低于死亡组(P<0.05);2组性别、胎龄、出生体重、母亲年龄、病因、剖宫产、双胎、羊水异常差异无统计学意义(P>0.05)。按照胸部X线片表现分组,104例患儿轻度患儿73例,重度患儿31例。轻度组miR-210水平、SNAPPE-Ⅱ评分低于重度组(P<0.05)。NRDS发生与血清miR-210水平呈正相关(r=0.638,P<0.001)。血清miR-210与SNAPPE-Ⅱ评分呈正相关(r=0.513,P<0.05)。血清miR-210的最佳分界值为16.71 ng/L时,曲线下面积为0.763,OR=0.846,95%CI:0.892~1.064,敏感度为82.61%,特异度为86.42%。结论 血清miR-210水平升高与NRDS病情严重程度以及预后密切相关,血清miR-210水平与NRDS病情程度呈正相关性,当血清miR-210临界值为16.71 ng/L时对评估NRDS患儿预后具有较高价值。  相似文献   
2.
ObjectivePregnancies complicated by fetal heart defects often undergo a planned delivery prior to term by either induction of labour or cesarean delivery to ensure optimal availability of neonatal care. We aimed to assess whether such planned deliveries achieve their goal of better perinatal care.MethodsWe conducted a retrospective case-control study of pregnancies complicated by isolated fetal cardiac defects, without other fetal comorbidities, managed at a single fetal medicine unit over a 10-year period. Only pregnancies delivered past 37 weeks gestation were included. Patients undergoing elective delivery for care planning reasons only were compared with patients in whom planned delivery was clinically indicated and patients who laboured spontaneously. Obstetric and perinatal outcomes were recorded.ResultsOf the 180 pregnancies included in the study, 59 (32.8%) were in the elective group, 49 (27.2%), in the indicated group, and 72 (40%), in the spontaneous group. Mean gestational age at delivery was 39.0 ± 1.1 weeks overall and did not differ between the groups. For the elective group, only 35.6% of deliveries occurred during office hours, which was similar to the 2 other groups. The rate of adverse obstetric or postnatal outcomes was not statistically significantly different between groups.ConclusionTimed delivery at term does not seem to be associated with an increased risk of poor perinatal outcomes. It may improve perinatal care by providing proximity to a neonatal intensive care unit and convenience for patients and providers.  相似文献   
3.
目的探讨妊娠晚期孕妇抑郁情绪对新生儿神经行为发育的影响。方法选取2017年1月—2018年12月,收治本院的160例妊娠晚期孕妇抑郁情绪患者一般临床资料,妊娠周期28周以上,对孕妇抑郁情绪进行统计采用爱丁堡抑郁自评量表、负性认知加工偏向量表,对新生儿神经行为进行评估时按照婴儿神经国际量表。结果160例妊娠晚期孕妇抑郁情绪患者中,阳性30例、阴性130例,与阴性妊娠妇女相比,抑郁阳性妊娠妇女负性沉思偏向、负性解释偏向、负性记忆偏向、负性注意偏向均显著较高,差异具有统计学意义(P<0.05)。160例新生儿中,婴儿神经国际量表评分处于临界值为60例,正常值为100例,神经行为异常发生率为37.50%,负性沉思偏向、负性注意偏向与婴儿神经国际临界值呈负相关关系(P<0.05);与抑郁自评量表无明显相关性(P>0.05)。结论妊娠晚期孕妇具有较高抑郁发生率,其中负性认知加工偏向中负性沉思偏向、负性注意偏向与新生儿神经行为发育具有明显相关性。  相似文献   
4.
目的观察呋塞米注射液在新生儿湿肺中的疗效。方法选取2018年1月—2019年12月医院新生儿科收治的新生儿湿肺70例,随机分为试验组35例和对照组35例,二组性别、胎龄、出生体质量、生产方式的差异无统计学意义(P>0.05),试验组在对照组常规治疗的同时加用静注呋塞米注射液0.5 mg/(kg·d),疗程3 d,比较两组平均住院时间、停氧时间、48小时内症状缓解例数。结果平均住院时间:试验组(5.00±1.31)d,对照组(6.06±1.75)d;总用氧时间:试验组(49.04±18.23)h,对照组(63.80±24.11)h;48 h内呼吸症状改善者:试验组24例(68.57%),对照组15例(42.86%),二组比较在平均住院时间、总用氧时间及48小时内症状缓解例数,差异均有统计学意义(P<0.05)。结论呋塞米注射液治疗新生儿湿肺在平均住院时间、总用氧时间和48小时内呼吸症状缓解优于对照组,有一定的疗效。  相似文献   
5.
6.
ObjectiveTo compare maternal psychological well-being, newborn behavior, and maternal and newborn salivary oxytocin (OT) and cortisol before and after two maternally administered multisensory behavioral interventions or an attention control group.DesignRandomized prospective clinical trial.SettingU.S. Midwest community hospital.ParticipantsNewborns and their mothers (n = 102 dyads) participated. Mothers gave birth vaginally at term gestation and had no physical or mental health diagnoses. Newborns with low Apgar scores, receipt of oxygen, suspected infection, or congenital anomalies were excluded.MethodsDyads were randomly assigned to the auditory, tactile, visual, and vestibular (ATVV) intervention, the ATVV with odor from a baby lotion (ATVVO), or the attention control (AC) Group. Maternal psychological well-being, newborn behavior, and endocrine responses (salivary cortisol and OT) were measured before and after the intervention.ResultsNewborns in the ATVV and ATVVO groups exhibited increases in potent engagement behaviors (p < .0001 and p = .001, respectively). Newborns in the AC group exhibited a decrease in potent engagement (p = .013) and an increase in potent disengagement (p = .029). Mothers in the ATVVO group exhibited an increase in OT (p = .01) and the largest change in OT (p = .02) compared to mothers in the ATVV and AC groups. We noted no change in maternal psychological well-being or newborn endocrine responses.ConclusionInclusion of an odor via lotion with a behavioral intervention (ATVV) influenced maternal OT more than the behavioral intervention alone. Newborns were behaviorally responsive to the interventions; however, endocrine measures were not associated with intervention changes.  相似文献   
7.
8.
This Special Issue aims to examine the crucial role of nutritional status starting from pregnancy in modulating fetal, neonatal and infant growth and metabolic pathways, with potential long-term impacts on adult health. Poor maternal nutritional conditions in the earliest stages of life during fetal development and early life may induce both short-term and longer lasting effects; in particular, an increased risk of noncommunicable diseases (NCDs) and other chronic diseases such as obesity, which itself is a major risk factor for NCDs, is observed over the lifespan. Poor maternal nutrition affects the fetal developmental schedule, leading to irreversible changes and slowdown in growth. The fetus limits its size to conserve the little energy available for cardiac functions and neuronal development. The organism will retain memory of the early insult, and the adaptive response will result in pathology later on. Epigenetics may contribute to disease manifestation affecting developmental programming. After birth, even though there is a limited evidence base suggesting a relationship between breastfeeding, timing and type of foods used in weaning with disease later in life, nutritional surveillance is also mandatory in infants in the first year of life. We will explore the latest findings on nutrition in early life and term and preterm babies, as well as the role of malnutrition in the short- and long-term impact over the lifespan. Focusing on nutritional interventions represents part of an integrated life-cycle approach to prevent communicable and non-communicable diseases.  相似文献   
9.
目的探讨新生儿胃穿孔的临床特点及影响预后的相关因素。方法本研究为回顾性研究。研究对象为山西省儿童医院新生儿外科2008年1月至2017年12月手术治疗的49例新生儿胃穿孔病例。分析这些患儿的临床表现、辅助检查、手术情况及预后等临床资料。根据预后将患儿分为存活组和死亡组,探讨影响患儿预后的相关因素。采用独立样本t检验或连续性校正χ^2检验(或Fisher精确概率法)分析数据。结果(1)49例患儿中,男29例(59.2%),女20例(40.8%);早产儿30例(61.2%),足月儿19例(38.8%);体重(2450±700)g,范围为1010~5000 g。29例(59.2%)为低出生体重儿。11例(22.4%)有围产期不良事件;17例(34.7%)术前合并感染性休克;6例(12.2%)合并其他消化道畸形。2例(4.1%)有生后窒息复苏史,2例(4.1%)合并呼吸窘迫综合征行机械通气,12例(24.5%)有留置胃管或洗胃史。(2)49例患儿的发病时间为(3.8±2.0)d,47例(95.9%)于生后1周内发病,其中36例于生后≤4 d发病;25例(51.0%)发病到手术时间≤12 h。(3)首发症状以单纯腹胀最常见[69.4%(34/49)],12例(24.5%)腹胀伴呕吐,39例(79.6%)患儿术前腹部立位X射线片可见膈下大量游离气体,肝脏受压下移,胃泡影减小或消失。(4)所有患儿入院后均急诊行开腹探查、胃壁一期修补术。术中见27例(55.1%)穿孔位于胃大弯,5例(10.2%)位于胃小弯,14例(28.6%)位于胃前壁,3例(6.1%)位于胃后壁。33例(67.3%)穿孔长径≥3 cm。术后3例(6.1%)发生切口感染,2例(4.1%)吻合口漏;1例术后48 h发现大量气液胸,再次手术证实为食道重复并食道穿孔。(5)49例中,35例(71.4%)的病因为先天性胃壁肌层缺损,4例(8.2%)为损伤,10例(20.4%)为自发性穿孔。(6)49例中,8例(16.3%)死亡,36例(73.5%)存活,5例(10.2%)术后放弃治疗。剔除5例放弃治疗的患儿后,存活组中发病到手术时间≤12 h及穿孔长径<3 cm患儿的比例高于死亡组[61.1%(22/36)与1/8,χ^2=4.404;41.7%(15/36)与0/8];死亡组合并感染性休克的比例高于存活组[6/8与22.2%(8/36),χ^2=6.147](P值均<0.05)。结论新生儿胃穿孔病死率较高,先天性胃壁肌层缺损是新生儿胃穿孔的病理基础和主要病因,突然出现的腹胀是其主要的临床表现。尽早手术有助于提高治愈率。  相似文献   
10.
本文报告1例围产期新型冠状病毒感染患者的诊治经过及围产结局。孕妇孕37周+2因"严重肝功能异常"行急诊剖宫产娩出一活男婴。术后第2天产妇出现发热,经咽拭子核酸检测确诊新型冠状病毒感染。经隔离及对症支持治疗12 d,连续2次核酸检测阴性痊愈出院。患者血、尿、乳汁及新生儿咽拭子均未检测到新型冠状病毒核酸。新生儿心肌酶升高,隔离14 d后痊愈出院。  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