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   1732篇
  免费   51篇
  国内免费   83篇
耳鼻咽喉   13篇
儿科学   16篇
妇产科学   21篇
基础医学   210篇
口腔科学   37篇
临床医学   184篇
内科学   158篇
皮肤病学   12篇
神经病学   31篇
特种医学   134篇
外科学   82篇
综合类   220篇
预防医学   256篇
眼科学   63篇
药学   133篇
中国医学   131篇
肿瘤学   165篇
  2023年   4篇
  2022年   4篇
  2021年   8篇
  2020年   5篇
  2019年   8篇
  2018年   12篇
  2017年   7篇
  2016年   5篇
  2015年   9篇
  2014年   12篇
  2013年   13篇
  2012年   27篇
  2011年   101篇
  2010年   58篇
  2009年   35篇
  2008年   44篇
  2007年   36篇
  2006年   47篇
  2005年   73篇
  2004年   316篇
  2003年   201篇
  2002年   149篇
  2001年   127篇
  2000年   86篇
  1999年   111篇
  1998年   71篇
  1997年   65篇
  1996年   60篇
  1995年   32篇
  1994年   28篇
  1993年   39篇
  1992年   21篇
  1991年   18篇
  1990年   16篇
  1989年   11篇
  1988年   4篇
  1987年   2篇
  1984年   1篇
排序方式: 共有1866条查询结果,搜索用时 15 毫秒
1.
Objectives:To assess the outcome and impact of multiple sclerosis (MS) using validated Arabic versions of the Barthel index (BI) multiple sclerosis impact scale (MSIS-29), the modified Rankin scale (mRS), and the expanded disability status scale (EDSS).Methods:A cross-sectional study conducted at King Abdulaziz Medical City in Riyadh, Kingdom of Saudi Arabia, during July-November 2017. All Saudi adult patients diagnosed with MS between 2000-2016 (269 patients) were included. Patients were contacted via phone calls and were assessed using a newly developed and validated multi-component questionnaire that included demographic data, disease course, and Arabic versions of the scales.Results:Out of 269 patients, 210 (78.2%) responded. The average patient age was 37.44±10.3 years. The majority were females (69.5%). Only, 51 (24.3%) patients reported worsening conditions. Annually, the average relapse rate was 2.28±1.91. In regard to patient outcomes, 120 (57.1%) showed no significant disability in mRS, 146 (69.5%) were ambulatory without aid in EDSS, and 185 (89.4%) were independent in BI scores. The average MSIS-29-PHYS score was 33.6±27.6 and MSIS-29-PSYCH score was 38.2±25.8. Modified Rankin scale and EDSS were significantly associated with the current use of disease-modifying therapy (DMT). Modified Rankin scale was negatively associated with delayed diagnosis. Barthel index showed significant association with medication compliance and the absence of attacks.Conclusion:Majority of patients had a favorable outcome that was linked with the use of DMT, compliance, early diagnosis, and absence of attacks.

Multiple sclerosis (MS) is a neurological disease that is singularly characterized by multifocal areas of demyelination in the central nervous system (CNS). Though its precise etiology is unclear, the pathogenesis of the disease is believed to be immune-mediated myelin destruction and, eventually, axon disruption, which is the main cause behind the progressive disability.1 Multiple sclerosis is the most common neurological autoimmune disorder in the world, with an estimated number of 2.3 million until 2013. The increase from 2.1 million in 2008 to 2.3 million in 2013 has raised not only epidemiologists’ interest and alarm but also neurologists’.2 As of Kingdom of Saudi Arabia, it was estimated that 40/100,000 is the prevalence of multiple sclerosis in 2008.3 When it comes to gender, women are generally more affected than men, estimated by a study carried out in Kingdom of Saudi Arabia.4 Affected person’s average age of onset is 30 years.The outcome and prognosis of MS do not only vary depending on a plethora of factors but are also unpredictable in nature. It is well-recognized in the literature that MS can cause disability with varying degrees, and this can have an impact on patients’ quality of life (QoL) and daily activities.5 However, the outcome is not thoroughly studied, especially in Kingdom of Saudi Arabia. To predict MS patient outcomes, conventional and physician-based validated scales are usually used, one of which is the EDSS. It mainly assesses the degree of disability and monitors the diseases’ progression but with several limitations which are documented, such as its insensitivity to change over a spectrum of 2-3 years.6 Therefore, in this study, we additionally considered other vital scores and scales that not only assess disability via the EDSS, but also the mRS. Moreover, health-related quality of life (HRQoL) is evaluated by the MSIS-29 and the BI. Such measures will help us to have a more objective and reliable endpoint regarding the patients’ outcome and survival.In this study, we hypothesised that the outcome in regard to disability and HRQoL would differ depending on the variables we took into consideration when assessing MS. Thus, the aim was to evaluate the outcome of this neurological disease that we call MS.  相似文献   
2.
Obesity can spread more easily if it is not perceived negatively. This issue may be more pronounced among the poor, a conjecture that we test in this paper. We start with general evidence on the concave relationship between income and obesity, both across countries and within Mexico, a country characterized by very unequal development levels and the highest obesity rate in the world. We suggest a general model that explains this stylized fact from a simple necessary condition, namely, the complementarity between nonfood consumption and health concerns. Then, we test the direct effect of overweight on mental health among Mexican women. We find a positive effect of obesity in the low consumption group and a depressing effect among the rich. This result is robust to the inclusion of a range of confounders (childhood conditions, lifestyle variables, food expenditure, and household shocks) and after instrumenting individual fatness by the variation in genetic predisposition. The complementarity between living standards and weight concerns may reflect different norms, different labor market penalties, or simply different returns to healthy time across the social spectrum.  相似文献   
3.
目的研究快速成型(RP)技术辅助下制作的个体化假体复合珊瑚羟基磷灰石(CHA)、重组人骨形成蛋白2(rhBMP-2)修复兔下颌骨缺损的成骨效果。 方法以27只新西兰大白兔为实验对象,随机数字表法平均分成3组(每组9只),全部建立下颌骨连续性缺损模型,并在兔下颌骨缺损区分别植入个体化假体+自体骨(A组)、个体化假体+CHA(B组)、个体化假体+CHA+rhBMP-2(C组)。分别于术后4、12、24周3个时间点处死动物取材,进行大体标本观察,以及骨钙素(OC)、Ⅰ型胶原(COL-1)的免疫组化观察,分别比较各组修复骨缺损的能力,并对实验数据进行重复测量设计资料的单因素方差分析。 结果术后24周各组实验兔外形均对称,通过OC及COL-1的吸光度检测,骨缺损区均有大量新骨形成,A组(0.537 ± 0.010)、C组(0.530 ± 0.010)可见大量骨小梁及编织骨结构,缺损区的新骨OC、COL-1的免疫组化观察基本一致,差异无统计学意义(t = 0.007,P>0.05);但A组强于B组(0.415 ± 0.009,t = 0.122,P<0.001);C组也强于B组(t = 0.121,P<0.001),差异均有统计学意义。 结论在兔下颌骨缺损修复中,通过RP技术和组织工程技术相结合,CHA复合rhBMP-2后成骨能力明显增强,成骨效能肯定,为后期的临床应用提供可靠的实验基础。  相似文献   
4.
羟基磷灰石涂层热处理晶化工艺研究   总被引:13,自引:0,他引:13  
目的:通过热处理方法提高羟基磷灰石(HA)涂层的结晶度、使脱落的羟基得到恢复。方法:通过等离子喷涂和热处理试验,利用X射线衍射(XRD)和红外吸收光普分析等手段研究了热处理对羟基磷石涂层相组成的影响。结果:热处理可使涂层中的非晶相发生晶化,并使羟基得到恢复;随着热处理温度的提高,涂层的结晶度提高,α-TCP等热分解相逐步转变为羟基磷灰石。保温时间达到2小时后,延长保温时间并不能提高涂层的结晶工。结论:在大气环境下,涂层的最佳热处理工艺是在700℃下保温2小时。  相似文献   
5.
CDIC柱状种植体周龈下菌群变化的2年观察   总被引:1,自引:0,他引:1  
目的:了解种植体周龈下菌群构成变化与种植体周围组织炎的关系,方法:观察64枚CDIC种植体植入术后2年内种植体周龈下细菌构成变化以及相关临床指标。结果:种植体植入术后1月、3月、6月的龈下球菌比值降低。螺旋体,梭形菌比值增高,杆菌,弯曲菌比值差异无显著性意义。术后12月,24月这五类菌的比值接近术前水平,临床菌斑指数,龈沟出血指数高者,种植体周龈下细菌中球菌的比值较低,梭形菌,螺旋体的比值较高。结论:早期进行口腔卫生指导和定期细菌学检测,对提高种植义齿成功很有必要。  相似文献   
6.
目的:研究成人严重骨性Ⅲ类错畸形在正颌外科治疗的术前与术后正畸的特点及难点。方法:成人严重骨性Ⅲ类错病例35例,对该类畸形的临床特点、正颌手术前后正畸治疗方法和注意事项进行分析研究。结果:术前正畸治疗必须完成个别牙齿错位的调整,纠正牙弓形态与宽度的不调和牙齿代偿的去除;术后正畸的主要目的是牙弓内残留间隙的关闭和咬合关系的进一步精细调整。结论:只有完善的术前、术后正畸治疗与正颌外科手术相互配合,才能较好地完成成人严重骨性Ⅲ类错的临床治疗。  相似文献   
7.
应用经食管脉冲多普勒超声在术中测定了76例不同心脏病患者的左上肺静脉血流频谱。结果显示:Rv和SF%分别与同步测定的平均左房压间存在高度相关性(r=-0.88和r=-0.87);以SF%小于52%预测平均左房压大于2.0KPa时,其敏感性和特异性分别为93%和85%。结论认为,应用经食管脉冲多普勒测定肺静脉血流频谱能准确估测平均左房压,为定量评价左室舒张功能提供了新途径  相似文献   
8.
非典型川崎病冠状动脉的超声改变   总被引:18,自引:0,他引:18  
目的:提高临床对非典型川崎病的早期诊断能力。方法:回顾性分析24例非典型川崎病的二维超声表现。结果:非典型川崎病的超声表现:1.冠状动脉内径正常,但管壁回声增粗,增强,内膜形态不规则呈波浪状,虫蚀样及管腔同模糊等形态不的改变。2、壁回声明显增厚,增强,管腔变窄;3、冠状动脉轻度扩张,壁回声不均匀增粗,增强,4、冠状动脉明显扩张,冠状动脉瘤形成。结论:超声心动图对于早期诊断非典型川崎病,及时给予正确治疗,减轻冠状动脉的损害有着非常重要的意义。  相似文献   
9.
目的探讨甘氨酸龈下喷砂联合引导组织再生术(GTR)治疗种植体周围炎的有效性。 方法28例伴有牙槽骨吸收的种植体周围炎患者,按照随机、双盲、对照原则将种植体(共34枚)分成2组,分别行GTR,其中试验组(n= 18)在术中使用甘氨酸龈下喷砂系统对种植体表面进行清创;对照组(n= 16)采用塑料刮治器对种植体表面进行清创。在治疗前(基线)、治疗后3个月、治疗后6个月和治疗后12个月进行临床指标的检测,包括菌斑指数(PLI)、出血指数(BI)、探诊深度(PD)、临床附着水平(CAL)及影像学垂直骨增量。数据采用重复测量资料的方差分析,每个时间点采用独立样本t检验进行分析,试验组和对照组分别进行治疗前与治疗后的自身对比,并在基线、治疗后3个月、治疗后6个月和治疗后12个月进行临床指标的组间对比,以P<0.05为差异有统计学意义。 结果在基线,试验组和对照组各临床指标差异无统计学意义(P>0.05)。各组术后PLI、BI、PD、CAL及影像学垂直骨增量均较治疗前(基线)有明显改善,差异有统计学意义(P<0.05)。患者治疗后3个月,试验组与对照组BI、PLI、PD、CAL差异均有统计学意义(tBI= 5.103,PBI= 0.031;tPLI= 5.556,PPLI= 0.025;tPD= 4.440,PPD= 0.043;tCAL= 4.879,PCAL= 0.034)。患者治疗后6个月,试验组和对照组的PD、CAL差异均有统计学意义(tPD= 4.994,PPD= 0.033;tCAL= 4.831,PCAL= 0.035)。患者治疗后12个月,试验组和对照组的PD、CAL差异均有统计学意义(tPD= 4.302,PPD= 0.046;tCAL= 4.325,PCAL= 0.048)。患者治疗后6及12个月,试验组与对照组种植体的PLI和BI均有改善,但差异无统计学意义(P>0.05)。患者影像学垂直骨增量在治疗后3、6、12个月试验组较对照组增加更明显,差异均有统计学意义(t3=4.831,P3= 0.035;t6= 4.412,P6= 0.044;t12= 5.087,P12= 0.031)。 结论在改善种植体周围炎炎症水平及促进牙槽骨再生方面,甘氨酸龈下喷砂联合GTR较机械刮治联合GTR更具优势,可考虑在GTR中使用甘氨酸龈下喷砂来提高种植体周围炎的治疗效果。  相似文献   
10.
氟对小鼠胸腺及上皮细胞形态与功能的影响   总被引:3,自引:0,他引:3  
目的研究氟化物对胸腺上皮细胞的毒性作用及对胸腺细胞发育的影响,探讨其作用机制。方法采用小鼠胸腺上皮细胞原代体外培养及与胸腺细胞混合培养技术,观察不同剂量氟化钠(NaF)对小鼠胸腺上皮细胞形态与功能的损伤情况及胸腺细胞在NaF处理的小鼠胸腺上皮细胞环境中的生长发育状况。结果染氟组可见小鼠胸腺上皮细胞胞体变圆,折光性增强,胞浆内有空泡形成,小鼠胸腺上皮细胞培养基中乳酸脱氢酶(LDH)活性增强,胸腺上皮细胞合成DNA和蛋白质的能力降低,白细胞介素1(IL-1)分泌量减少,并呈一定的剂量反应关系。不同剂量NaF处理的小鼠胸腺上皮细胞与新鲜的胸腺细胞混合培养,随着染氟剂量的增加,胸腺细胞摄取3H-Tdr和3H-Leu的能力降低,活细胞数目逐渐减少。结论高氟能够直接损伤小鼠胸腺上皮细胞、破坏胸腺微环境,进而导致胸腺细胞发育障碍,影响免疫功能。  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