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   6146篇
  免费   670篇
  国内免费   346篇
耳鼻咽喉   60篇
儿科学   65篇
妇产科学   69篇
基础医学   600篇
口腔科学   101篇
临床医学   916篇
内科学   781篇
皮肤病学   48篇
神经病学   261篇
特种医学   178篇
外国民族医学   6篇
外科学   486篇
综合类   1401篇
现状与发展   4篇
一般理论   1篇
预防医学   526篇
眼科学   194篇
药学   716篇
  9篇
中国医学   373篇
肿瘤学   367篇
  2024年   29篇
  2023年   90篇
  2022年   240篇
  2021年   314篇
  2020年   297篇
  2019年   195篇
  2018年   204篇
  2017年   231篇
  2016年   185篇
  2015年   298篇
  2014年   355篇
  2013年   437篇
  2012年   549篇
  2011年   509篇
  2010年   456篇
  2009年   378篇
  2008年   422篇
  2007年   390篇
  2006年   319篇
  2005年   277篇
  2004年   226篇
  2003年   182篇
  2002年   148篇
  2001年   118篇
  2000年   78篇
  1999年   54篇
  1998年   33篇
  1997年   30篇
  1996年   22篇
  1995年   19篇
  1994年   17篇
  1993年   4篇
  1992年   8篇
  1991年   8篇
  1990年   7篇
  1989年   9篇
  1988年   8篇
  1987年   2篇
  1986年   4篇
  1985年   1篇
  1984年   1篇
  1983年   1篇
  1979年   1篇
  1974年   1篇
  1973年   2篇
  1970年   1篇
  1965年   1篇
  1828年   1篇
排序方式: 共有7162条查询结果,搜索用时 15 毫秒
121.
目的:建立测定新生儿体内氟康唑血药浓度的高效液相色谱(HPLC)法。方法:HPLC色谱条件为色谱柱Diamonsil C18柱(5 μm,4.6mm×250 mm);流动相甲醇﹕磷酸盐缓冲液(pH 7.0)=45︰55;检测波长261 nm;流速1 mL/min;柱温30℃;进样量10 μL。供试品溶液的制备,取样品加入内标后用乙酸乙酯萃取,有机相用氮气吹干,以甲醇溶解,进样测定。结果:该方法氟康唑在1.0~50.0 μg/mL范围内有良好线性关系,精密度、稳定性及回收率较好。结论:该方法操作简单、重复性好、准确可靠,可作为新生儿体内预防用氟康唑HPLC含量测定的方法。  相似文献   
122.
ObjectiveThe purpose of this study was to review the literature on the effect of scraping therapy on chronic low back pain (LBP) from randomized controlled trials (RCTs).MethodsThree English medical electronic databases (PubMed, Embase, and the Cochrane Library) and 2 Chinese databases (China National Knowledge Infrastructure and Wanfang) were searched. Only randomized controlled trials related to the effects of scraping therapy on chronic LBP were included in this systematic review. Study selection, data extraction, and validation were conducted independently by 2 reviewers. The methodological quality of the studies was evaluated by the Cochrane risk-of-bias tool. RevMan 5.3 software was applied to perform meta-analysis of the data.ResultsTen studies comprising 627 participants were included. Overall, the quality of evidence was moderate owing to a lack of blinding and allocation concealment in some studies and unclear risk of selective reporting. Meta-analysis of 9 RCTs indicated that scraping therapy had a statistically significant effect on pain reduction (standard mean difference = ?0.66, 95% confidence interval [CI], ?0.83 to ?0.49, P < .001). However, if only a single scrape treatment was carried out, the results did not show that scraping was superior to the control group regarding pain relief (mean difference = ?0.35, 95% CI, ?1.23 to 0.53, P = .44). Moreover, the results of 6 RCTs involving 468 participants showed significantly greater improvement in lumbar dysfunction (mean difference = ?10.05, 95% CI, ?13.52 to ?2.32, P < .001). In addition, the results of 5 RCTs involving 393 participants showed a favorably significant effect on the overall efficacy (odds ratio = 4.74, 95% CI, 2.34-9.62, P < .001). As for follow-up effects, meta-analysis of 3 RCTs involving 241 participants showed a promising effect on pain reduction and lumbar function improvement at 1 month and 3 months after the end of treatment, respectively. Only 1 study reported adverse effects, and none were serious.ConclusionScraping therapy may have a therapeutic effect for some individuals with chronic LBP. However, due to the limited amount of research and the low methodological quality of the included studies, additional large-scale, multicenter, high-quality RCTs on relieving pain intensity and improving lumbar dysfunction are still necessary.  相似文献   
123.
Hypervirulent invasive group A streptococcus (GAS) isolates inhibit neutrophil infiltration more than pharyngitis isolates do, and the molecular basis of this difference is not well understood. This study was designed to first determine whether natural null mutation of the two-component regulatory system CovRS is responsible for the enhancement of the inhibition of neutrophil recruitment seen in hypervirulent GAS. Next, we examined the role of CovRS-regulated interleukin-8/CXC chemokine peptidase (SpyCEP), C5a peptidase (ScpA), and platelet-activating factor acetylhydrolase (SsE) in the enhanced innate immune evasion. Invasive isolate MGAS5005 induces less neutrophil infiltration and produced a greater lesion area than pharyngitis isolate MGAS2221 in subcutaneous infections of mice. It is known that MGAS5005, but not MGAS2221, has a natural 1-bp deletion in the covS gene. Replacement of covSΔ1bp in MGAS5005 with wild-type covS resulted in the MGAS2221 phenotype. Deletion of covS from MGAS2221 resulted in the MGAS5005 phenotype. Tests of single, double, and triple deletion mutants of the MGAS5005 sse, spyCEP, and scpA genes found that SsE plays a more important role than SpyCEP and ScpA in the inhibition of neutrophil recruitment and that SsE, SpyCEP, and ScpA do not have synergistic effects on innate immune evasion by MGAS5005. Deletion of sse, but not spyCEP or scpA, of MGAS2221 enhances neutrophil recruitment. Thus, covS null mutations can cause substantial inhibition of neutrophil recruitment by enhancing the expression of the chemoattractant-degrading virulence factors, and SsE, but not SpyCEP or ScpA, is required for CovRS-regulated GAS inhibition of neutrophil infiltration.  相似文献   
124.
125.
肱骨髁上骨折常见于7岁以下儿童,约占儿童肢体骨折的30%和肘部骨折的50%~70%;根据受伤机制的不同可分为伸直型和屈曲型,其中伸直型约占96%~98%、屈曲型约占2%~4%,是最常见的儿童骨折之一[1,2]。Gartland分型是目前应用最广泛的肱骨髁上骨折分型系统:Ⅰ型骨折无移位常采取保守治疗,Ⅱ型和Ⅲ型骨折因创伤严重致治疗棘手。由于儿童肱骨远端特殊的解剖生理特点,尺神经、正中神经及桡神经均容易损伤,文献报道肱骨髁上骨折导致的神经损伤发生率高达10%~20%[1-3],医源性神经损伤也高达3%~6%[2-4],给临床带来严重挑战。本文就儿童肱骨髁上骨折伴神经损伤的研究进展作一综述。  相似文献   
126.
目的:分析儿童期父母社会经济地位对子代成年期抑郁的影响,评价社经地位相关的健康的代际不公平效应.方法:本研究选取2013年中国健康与养老追踪调查数据.采用流行病学调查用抑郁量表(CES-D)评定抑郁情况,以儿童期父母受教育水平与职业作为社经地位变量,运用集中曲线与集中指数法分析社经地位与抑郁分布的不平等状况.结果:儿童期父母社经地位越高,子代抑郁水平越低(β=-0.300,P=0.002),较高的抑郁水平在来自较低收人家庭的人群中堆积(CI=-6.24%,P=0.008).结论:儿童期社经地位对成年期抑郁具有长期、持续的影响,并存在代际不公平效应,该社会问题应以较低社经地位人群为优先关注点,通过多部门合作来减少不公平现象.  相似文献   
127.
Tao  Bei  Xiang  Wei  Li  Xianglong  He  Chengsong  Chen  Ligang  Xia  Xiangguo  Peng  Tangming  Peng  Lilei  Yang  Xiaobo  Zhong  Chuanhong 《Inflammation research》2021,70(3):285-296
Objective

microRNAs (miRNAs) play critical roles in embryogenesis, cell differentiation and the pathogenesis of several human diseases, including systemic lupus erythematosus (SLE). Toll-like receptors (TLRs) are also known to exert crucial functions in the immune response activation occurring in the pathogenesis of autoimmune diseases like SLE. Herein, the current study aimed to explore the potential role of miR-152-3p in TLR-mediated inflammatory response in SLE.

Methods

We determined the miR-152-3p expression profiles in CD4+ T cells and peripheral blood mononuclear cells (PBMCs) harvested from patients with SLE and healthy controls, and analyzed the correlation between miR-152-3p expression and clinicopathological parameters. CD70 and CD40L expression patterns in CD4+ T cells were assessed by RT-qPCR and flow cytometry. ChIP was adopted to determine the enrichment of DNA methyltransferase 1 (DNMT1) in the promoter region of myeloid differentiation factor 88 (MyD88).

Results

The obtained findings revealed that miR-152-3p was highly-expressed in CD4+ T cells and PBMCs of patients with SLE, and this high expression was associated with facial erythema, joint pain, double-stranded DNA, and IgG antibody. DNMT1 could be enriched in the MyD88 promoter, and miR-152-3p inhibited the methylation of MyD88 by targeting DNMT1. We also found that silencing miR-152-3p inhibited MyD88 expression not only to repress the autoreactivity of CD4+ T cells and but also to restrain their cellular inflammation, which were also validated in vivo.

Conclusion

Our study suggests that miR-152-3p promotes TLR-mediated inflammatory response in CD4+ T cells by regulating the DNMT1/MyD88 signaling pathway, which highlights novel anti-inflammatory target for SLE treatment.

  相似文献   
128.
目的 观察并比较3种途径(引流至角膜缘、赤道部及眼后节)植入医用硅胶管降眼压的效果。方法 选择健康新西兰白兔45只,单眼植入医用硅胶管将房水引流。根据植入途径分为角膜缘组、赤道部组和眼后节组,每组15只。结果 对各实验组术前、术后眼压值进行统计对比,术后4周内眼后节组降眼压幅度最大(26.6%),赤道部组次之(16.2%),角膜缘组最小(1.2%);术后1、2和4周,赤道部组、角膜缘组、眼后节组的术前、术后眼压值比较差异均有统计学意义(P<0.01);术后4周,眼后节组眼压下降幅度最大,且各组间眼压值差异均有统计学意义(P<0.01)。结论 将房水引流至眼后节时眼压下降幅度大,可为临床手术提供参考。  相似文献   
129.
目的:了解针对性口腔健康宣教对老年种植牙患者术后护理措施执行及护理效果的影响,为进一步提高老年种植牙患者的护理质量提供研究依据。方法:将接受口腔种植牙手术的112例老年患者随机分为试验组和对照组(各56例),对照组采用常规的健康宣教方式,试验组患者在常规宣教的基础上进一步实施有针对性的健康宣教,通过统计分析比较护理措施的执行率及护理效果。结果:试验组、对照组患者术后各项护理措施的执行率分别为90.9%和76.6%(χ^2=41.99,P<0.01),术后两周内感觉到疼痛的天数分别为2.07±1.89天和3.36±2.35天(t=3.28,P<0.01),两组患者中均未发现有术后伤口感染、早期治疗失败等情况的发生。结论:针对性健康宣教能够提高老年口腔种植患者护理措施的执行率,显著减少术后的疼痛反应时间。  相似文献   
130.
The International Journal of Cardiovascular Imaging - To establish a reference range and compare differences among three methods, and then to construct Z-score reference ranges in normal fetuses...  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