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   1896篇
  免费   141篇
  国内免费   36篇
耳鼻咽喉   4篇
儿科学   27篇
妇产科学   254篇
基础医学   187篇
口腔科学   22篇
临床医学   142篇
内科学   156篇
皮肤病学   25篇
神经病学   47篇
特种医学   70篇
外科学   246篇
综合类   261篇
预防医学   112篇
眼科学   8篇
药学   402篇
  2篇
中国医学   76篇
肿瘤学   32篇
  2023年   12篇
  2022年   31篇
  2021年   64篇
  2020年   57篇
  2019年   42篇
  2018年   61篇
  2017年   70篇
  2016年   78篇
  2015年   58篇
  2014年   124篇
  2013年   149篇
  2012年   95篇
  2011年   104篇
  2010年   88篇
  2009年   98篇
  2008年   90篇
  2007年   73篇
  2006年   101篇
  2005年   102篇
  2004年   59篇
  2003年   64篇
  2002年   62篇
  2001年   37篇
  2000年   27篇
  1999年   25篇
  1998年   21篇
  1997年   20篇
  1996年   17篇
  1995年   22篇
  1994年   14篇
  1993年   18篇
  1992年   18篇
  1991年   17篇
  1990年   13篇
  1989年   9篇
  1988年   14篇
  1987年   11篇
  1986年   10篇
  1985年   23篇
  1984年   18篇
  1983年   11篇
  1982年   15篇
  1981年   12篇
  1980年   7篇
  1979年   3篇
  1977年   2篇
  1976年   2篇
  1975年   1篇
  1970年   1篇
  1966年   2篇
排序方式: 共有2073条查询结果,搜索用时 234 毫秒
1.
Ovarian carcinoma is one of the most lethal malignancies, but only very few prognostic biomarkers are known. The degradome, comprising proteases, protease non-proteolytic homologues and inhibitors, have been involved in the prognosis of many cancer types, including ovarian carcinoma. The prognostic significance of the whole degradome family has not been specifically studied in high-grade serous ovarian cancer. A targeted DNA microarray known as the CLIP-CHIP microarray was used to identify potential prognostic factors in ten high-grade serous ovarian cancer women who had early recurrence (<1.6 years) or late/no recurrence after first line surgery and chemotherapy. In women with early recurrence, we identified seven upregulated genes (TMPRSS4, MASP1/3, SPC18, PSMB1, IGFBP2, CFI – encoding Complement Factor I – and MMP9) and one down-regulated gene (ADAM-10). Using immunohistochemistry, we evaluated the prognostic effect of these 8 candidate genes in an independent cohort of 112 high-grade serous ovarian cancer women. Outcomes were progression, defined according to CA-125 criteria, and death. Multivariate Cox proportional hazard regression models were done to estimate the associations between each protein and each outcome. High ADAM-10 expression (intensity of 2–3) was associated with a lower risk of progression (adjusted hazard ratio (HR): 0.51; 95% confidence interval (CI): 0.29-0.87). High complement factor I expression (intensity 2–3) was associated with a higher risk of progression (adjusted HR: 2.30, 95% CI: 1.17–4.53) and death (adjusted HR: 3.42; 95% CI: 1.72–6.79). Overall, we identified the prognostic value of two proteases, ADAM-10 and complement factor I, for high-grade serous ovarian cancer which could have clinical significance.  相似文献   
2.
目的 比较枸橼酸咖啡因和氨茶碱对早产儿神经行为发育的影响,为早产儿早期合理干预提供临床依据。方法 选择2014年6月-2018年6月在中国西电集团医院新生儿科住院接受枸橼酸咖啡因治疗的原发性呼吸暂停(AOP)早产儿62例作为研究组;2011 年 12 月-2014年5月同在中国西电集团医院新生儿科住院采用氨茶碱治疗的AOP患儿69例作为对照组。出生3~8 d及矫正胎龄40周时分别行头颅MRI检查,评估脑白质损伤(WMD)并进行两组比较;6个月及12个月时应用Gesell婴幼儿发育量表测试比较两组神经行为发育水平。结果 两组患儿在性别、出生胎龄及体重、产前孕母糖皮质激素应用及分娩方式、5 min Apgar评分、辅助通气和表面活性物质的应用等方面差异均无统计学意义(P>0.05)。首次头颅MRI显示两组患儿WMD差异无统计学意义(P>0.05)。矫正胎龄40周时头颅MRI显示,咖啡因组WMD较氨茶碱组明显改善,差异有统计学意义(P<0.05);且6个月及12个月时Gessell婴幼儿发育量表测试,随访至校正6月龄时,咖啡因组患儿的大运动、精细运动及个人-社交评分均高于氨茶碱组(P<0.05);随访至校正12月龄时,咖啡因组患儿的大运动、精细运动、语言、适应性评分均高于氨茶碱组(P<0.05)。结论 枸橼酸咖啡可明显改善AOP患儿6个月及12个月时的神经行为发育。  相似文献   
3.
4.
Changes of the neuronal discharge of 128 medullary respiratory unitswere recorded and studied during the period of expiratory apnea induced reflexlyby intracarotid sinus injection of sodium citrate in rabbits.Generally,theneuronal discharge of inspiratory units began,stopped and recovered at the sametime with those of the phrenic nerve.But,about 5% the phase-spanninginspiratory units near the obex showed a different time course with the dischargeof the phrenic nerve.They fired continuously in a low frequency while thephrenic nerve was quiet.When increasing progressively and approaching to acertain level,the firing rate increased abruptly and at the same time phrenic nervebegan to fire.So it seemed that they acted as the pacemaker of inspiration.Comparison of the cycle-triggered histograms(CTH)of these inspiratory unitswith those of phrenic nerve showed clearly the above mentioned phasicrelationship.They started firing before the phrenic nerve,but they reached theirmaximal rate and then declined and stopped quite in accordance with the phrenicnerve.It is,therefore,reasonable to assume that the central mechanism of theswitch from expiratory apnea to inspiration may originate from this kind ofneurons.Most of the expiratory units show tonic discharges during the period of apneawith a higher discharge rate than normal and then the rate decreases just beforerecovery of phrenic firing.In addition,small portion of the expiratory units weredepressed as the phrenic discharge ceased.The function of these two differentkinds of neurons in the mechanism of development of respiratory rhythm is,apparently,different.  相似文献   
5.
Effect of buffering on pharmacokinetics of ketoprofen enantiomers in man   总被引:1,自引:0,他引:1  
Aims Concomitant administration of magnesium hydroxide may affect the rate or extent of absorption of non-steroidal anti-inflammatory drugs. In order to find out whether or not buffering modifies the pharmacokinetics of ketoprofen, plasma concentration-time courses resulting from oral administration of unbuffered formulations were compared with those of buffered formulations.
Methods Two groups of 12 healthy and young male subjects were included in two randomized cross-over studies and received single oral doses of ketoprofen 12.5 or 25  mg, respectively, given as tablets which were either unbuffered or buffered with magnesium hydroxide/citrate. Ketoprofen enantiomers in plasma were determined by h.p.l.c. up to 24  h post-dose.
Results Maximum plasma concentrations ( C max ) of both the (R)- and (S)-enantiomer, observed after administration of the buffered formulations (12.5 and 25  mg), were higher compared with the unbuffered tablets by about 50–80%. The area under concentration-time data (AUC) was unaffected, and, hence, C max/AUC was increased by buffering. Time to C max ( t max ) and mean residence time (MRT) tended to be or was shortened by buffering.
Conclusions It is concluded that buffering of two ketoprofen formulations with magnesium hydroxide/citrate enhanced the concentration maximum by increasing the rate of absorption and leaving AUC unaffected.  相似文献   
6.
Summary Nephrolithiasis is presented in 18–40% of patients with primary hyperparathyroidism. Our work suggests that citrate, an inhibitor of calcium salts, could be involved in the presence of renal lithiasis because hyperparathyroid stone formers show less citrate elimination than nonstone formers.  相似文献   
7.
目的 探讨小剂量阿斯匹林在促排卵过程中对子宫血流及内膜厚度的影响及其作用机理。方法 采用前瞻性随机双盲的方法 ,对不明原因的不孕妇女在克罗米酚 (CC)促排卵治疗同时 ,自月经第 1~ 2 0d连续服用小剂量阿斯匹林 ,75mg/d。 结果 试验组子宫动脉血流阻力指数 (RI)明显低于对照组 (P <0 0 1) ,子宫内膜厚度明显较对照组厚 (P <0 0 5 )。结论 小剂量阿斯匹林可增加子宫血流供应 ,从而改善促排卵治疗时CC所致的子宫内膜发育不良  相似文献   
8.
克罗米芬兴奋试验预测卵巢储备功能的价值   总被引:1,自引:0,他引:1  
目的探讨克罗米芬兴奋试验(CCT)在不孕妇女中预测卵巢储备功能的作用。方法对2001年1月至2005年2月就诊于广东省妇幼保健院的666例不孕症患者作为研究对象,分为A组(≥35岁)461例为高龄组,B组(〈35岁)205例为低龄组,另取156例年龄〈35岁、非女方不孕原因者作为对照组,对三组受试者进行CCT。结果CCT异常发生率A组、B组及对照组分别为27.76%、34.14%、2.56%,A组及B组与对照组比较差异均有非常显著性意义(P〈0.01)。基础卵泡刺激素(FSH)〈10IU/L、雌二醇(E2)〈180pmot/L的不孕患者CCT异常发生率分剐为17.46%、24.19%,均明显低于FSH≥10IU/L、E2≥180pmol/L患者的64.19%及39.4%(P〈0.01)。结论CCT预测卵巢储备功能较基础FSH更敏感,CCT可作为常规了解卵巢储备功能的一项检测方法。  相似文献   
9.
长方案、短方案已在临床使用了20余年,这类超排卵方案采用降调节抑制内源性卵泡刺激素(FSH)、黄体生成素(LH)合成和释放,降低了过早排卵导致的周期取消,但也导致了促性腺激素用量大增、促排卵时间延长,即使是卵巢储备正常者也可能出现超排卵反应低下导致周期取消;卵巢储备低下患者则因不能超排而无缘体外受精胚胎移植(IVF-ET);同时,垂体抑制使卵巢反应增加,重度卵巢过度刺激综合征(OHSS)发生率增加.因传统的超排卵技术有上述不足,最近几年关于微刺激或轻刺激的讨论逐渐增多,轻微卵巢刺激的理念已被业界所认可[1-3].  相似文献   
10.
OBJECTIVE: To investigate the effect of improvement in erectile dysfunction (ED) on sexual function and satisfaction measures in heterosexual couples in which the woman reports that sexual intercourse is unsatisfactory at least half of the time. DESIGN: Multicentre, double-blind, placebo-controlled study. SETTING: Outpatient medical clinics. POPULATION: Hundred and eighty men with ED and their female partners in whom sexual intercourse was satisfactory about half the time or less (score of < or =3 on the Female Partner of ED Subject Questionnaire question 3 [FePEDS Q3]). METHODS: Men were randomised to flexible-dose sildenafil (25, 50, and 100 mg) or placebo as needed for 12 weeks. MAIN OUTCOME MEASURES: Primary: FePEDS Q3 ('Over the past four weeks, when you had sexual intercourse, how often was it satisfactory for you?') scored as 0 (no sexual activity) and 1 (almost never or never) to 5 (almost always or always). Secondary, partners: Sexual Function Questionnaire, Female Sexual Function Index (FSFI), and ED Inventory of Treatment Satisfaction (EDITS) partner version (EDITS-Partner). Secondary, men: International Index of Erectile Function (IIEF), General Efficacy Questions, event log data, Self-Esteem And Relationship questionnaire, and EDITS. Secondary, partners and men: Dyadic Adjustment Scale. RESULTS: The intention-to-treat population included 85 sildenafil recipients (mean age 59 +/- 12 years) and 91 placebo recipients (mean age 57 +/- 11 years). Most partners (aged 20-79 years; mean, 54 years) were postmenopausal. Sildenafil compared with placebo couples had greater improvement in the primary outcome (FePEDS Q3 [P < 0.0001]) and in sexual function, intercourse success rates, and secondary sexual satisfaction measures (FSFI satisfaction domain [P < 0.0001] and IIEF satisfaction domains [P < 0.001]) and had higher treatment satisfaction (EDITS and EDITS-Partner; P < 0.0001). Several predictors of improvement were identified, and improvement in one member of the couple correlated positively with improvement in the other member. CONCLUSIONS: The interdependence of sexual function and sexual satisfaction measures between members of couples consisting of men with ED and sexually healthy women reporting infrequent satisfactory sexual intercourse underscores the importance of including partners in ED treatment discussions.  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