Estimation of noise level and signal to noise ratio of laplacian electrocardiogram during ventricular depolarization and repolarization

Body surface Laplacian ECG (LECG) has demonstrated its enhanced capability to localize cardiac electrical sources closest to the recording site. The aim of the present study was to evaluate the noise level and signal to noise ratio (SNR) in the LECG as compared to the potential ECG (PECG). Such evaluation is important to determine the applicability of the LECG to localizing and imaging of cardiac electrical activity in an experimental setting. Experimental studies were conducted in six healthy men. A 150-channel PECG was recorded from the anterolateral chest and the LECG was estimated using the finite difference algorithm. The noise level in the PECG and LECG was evaluated using multiple estimation protocols. The signal level during ventricular depolarization and repolarization was also estimated, and the corresponding SNR was calculated. Different filtering techniques were examined to evaluate their effects on the noise level and SNR of the LECG and PECG. The experimental results indicate that with basic signal processing techniques (baseline adjustment, three-point moving average filter, and Wiener spatial filter), the SNR of the LECG is about 30-40% of that of the PECG. Furthermore, the SNR estimated during ventricular depolarization is about three times that obtained during ventricular repolarization for the PECG and LECG. The present study indicates that the LECG derived from the PECG using a local finite difference estimation procedure has satisfactory SNR during the periods of ventricular depolarization and repolarization, and suggests the feasibility of estimating the LECG from the recorded PECG in human subjects in an experimental setting.     

白三烯拮抗剂与糖皮质激素治疗轻、中度毛细支气管炎的疗效比较

目的:比较白三烯拮抗剂与糖皮质激素治疗小儿轻、中度毛细支气管炎(简称毛支)的疗效.方法:83例符合入组标准并完成观察的轻中度毛支患儿随机分为Ⅰ组、Ⅱ组、Ⅲ组,3组患儿均按毛支常规治疗,Ⅰ组为对照组不用激素及白三烯拮抗剂孟鲁司特,Ⅱ组加用孟鲁司特4 mgd-1,Ⅲ组加用强的松1～2 mgkg-1.d-1分3次口服.观察患儿的喘息及肺部哮鸣音消失天数.结果:Ⅰ组、Ⅱ组、Ⅲ组患儿喘息消失天数分别为5.14±1.73、4.81±1.56、7.39±1.94, Ⅱ组的治愈天数最少,与Ⅲ组比较有显著差异,但与对照组相比无显著差异.结论:白三烯拮抗剂治疗小儿轻、中度毛细支气管炎的疗效优于激素,提示轻中度毛支患儿不宜加用激素治疗.     

兔血管平滑肌细胞在低剂量电离辐射后的分子生物学变化

目的:观察体外培养的兔动脉平滑肌细胞(smoothmusclecells,SMCs)对γ射线照射的分子生物学机制。方法:取新西兰白兔(n=2)SMCs培养至第5～7代,对静止期SMCs分别给予γ射线2.5,5.0,10.0,20.0及30.0Gy一次性照射后继续培养4,24或72h。通过原位杂交方法观察γ射线对SMCs的c-fos与p53基因表达的影响。结果:低剂量γ射线照射后早期(4h左右)SMCsc-fosmRNA表达减少,p53mRNA表达增加,而高剂量γ射线照射及低剂量γ射线照射24h及72h时c-fos与p53基因表达无明显变化。结论:SMCs在低剂量电离辐射后,早期发生了c-fos与p53基因改变,c-fos与p53基因的改变可能参与了γ射线抑制SMCs的增殖过程。     

自动翻身卧位床的研制与应用

众所周知 ,长期卧床病人由于其本身不具有行为能力 ,因此必须长期卧床 ,这样很容易产生褥疮 ,不仅给病人带来极大痛苦 ,也给照顾者造成极大的负担。为此 ,我们研制的自动翻身卧位床保证了卧床病人在没有护理人员的情况下 ,可以通过遥控器按钮轻松自如地操作床板翻转 ,以实现病人的前倾、左倾及右倾卧位 ,大大减轻了护理人员的劳动强度 ,提高了病人自理的能力 ,避免了褥疮的发生。1　自动翻身卧位床的构造 (见图 1)　　病床的床体采用 4块活动的床板组成 ,分别通过 3只液压油缸支撑 ,病人通过按动操作控制器上的按钮即可达到左倾、右倾或前倾…     

聚焦超声治疗外阴上皮内非瘤样病变的有效性研究

目的评价超声治疗外阴上皮内非瘤样病变的临床疗效。方法根据随机化数字表按2：1的比例，将经病理确诊的90例外阴上皮内非瘤样病变患者随机分为超声治疗组（60例）和光谱治疗对照组（30例），于治疗后6个月评价两组的近期疗效和复发率。结果超声治疗组临床治愈29例，显效25例，好转6例，复发5例；光谱治疗组临床治愈1例，显效6例，好转19例，无效4例，复发21例。超声治疗组疗效优秀于对照组（Z=6.191．P=0.000），且复发率更低（X^2=-37.02，P=0.000），差异均有统计学意义。结论超声是目前治疗外阴上皮内非瘤样病变的一种有效方法。     

内镜套扎与硬化剂预防肝硬化食管静脉曲张再出血Meta分析

目的 比较套扎与硬化注射对食管静脉曲张出血患者的疗效,评价两者在二级预防中的价值。方法 检索Springer、Pubmed、Sinomed、CNKI、Cochrane Library,万方等数据库,用Cochrane图书馆的Rev Man5.1软件进行Meta分析。结果共纳入7项随机对照试验,结果显示,套扎治疗后再出血发生率显著低于硬化治疗（OR=0.54,95%CI：0.38~0.76,Z=3.56,P=0.000）;两者降低病死率方面相似（OR=0.79,95%CI：0.55~1.14,Z=1.27,P=0.21）;套扎组较硬化组能明显减少合并症（OR=0.22,95%CI：0.13~0.38,Z=5.51,P=0.000）;两组消除静脉曲张方面效果等同（OR=1.46,95%CI：0.98~2.18,Z=1.88,P=0.060）。漏斗图分析表明本研究对纳入文献评价的发表偏倚较小。结论 套扎较硬化注射在食管静脉曲张出血二级预防中疗效更佳。     

Interleukin-18 −137 G/C and −607 C/A polymorphisms and Alzheimer’s disease risk: a meta-analysis

The ?137 G/C and ?607 C/A polymorphisms in interleukin-18 (IL-18) gene have been reported to be associated with Alzheimer’s disease (AD) risk, but the results are inconclusive. Considering a single study may lack the power to provide reliable conclusion, we performed a meta-analysis to investigate the association between the IL-18 ?137 G/C and ?607 C/A polymorphisms and AD susceptibility. A comprehensive literature search of PubMed, Embase, China National Knowledge Infrastructure (CNKI) and Wanfang databases were conducted before September 1, 2015. The pooled odds ratio (OR) with 95 % confidence intervals (CIs) were calculated. Five eligible studies with a total of 1536 subjects were finally included in this meta-analysis. For the IL-18 ?137 G/C polymorphism, a significantly decreased risk was detected in patients carrying the C allele of ?137 G/C in all study subjects in allele model (C vs. G: OR = 0.816, 95 % CI = 0.680–0.980, p = 0.029). Moreover, stratification by ethnicity indicated markedly association between the ?137 G/C C allele and AD risk in Asians. For the IL-18 ?607 C/A polymorphism, a significantly decreased risk was found in patients carrying the A allele of ?607 C/A in all study subjects in dominant model (AA + CA vs. CC: OR = 0.696, 95 % CI = 0.529–0.915, p = 0.010). However, the results suggested no significant association between the ?607 C/A polymorphism and AD susceptibility when stratified by ethnicity. Our present meta-analysis suggests that the C allele carrier of IL-18 ?137 G/C was associated with decreased risk for AD in Asians. Further well-designed case–control studies with larger sample size and more ethnic groups are needed to confirm these conclusions.     

入院时糖化血红蛋白A1与脑出血患者预后的关系

目的 探究自发性脑出血（ICH）患者入院时糖化血红蛋白A1（HbA1c）水平与脑出血后90 d预后之间的关系。方法 前瞻性连续纳入2017年1-12月同济医院神经内科住院ICH患者,收集患者入院时相关临床资料,在患者出血后90 d使用改良的RANKIN量表评估其功能结局。构建单变量及多变量条件logistic回归模型,根据HbA1c测量值的四分位数将患者分为4组,以每组患者HbA1c的M为替代值纳入模型,计算趋势检验P值。应用限制性立方样条法拟合logistic回归模型,评估入院时HbA1c水平与ICH预后的关系。结果 共纳入ICH患者345例,其中预后良好214例,预后不良131例（严重残疾99例,死亡32例）。多因素logistic回归分析结果显示,随着入院时HbA1c升高,ICH后90 d发生预后不良的风险升高,趋势检验P<0.001（与HbA1c低水平组相比,中、高及极高水平组90 d预后不良的风险分别为OR=2.33,95%CI：1.07~5.07;OR=2.52,95%CI：1.12~5.64;OR=6.80,95%CI：3.01~15.34）。限制性样条结果显示,入院时HbA1c水平与ICH患者出血后90 d预后不良之间具有相关性（χ²=14.81,P<0.001）,且为线性关系（非线性检验：P=0.118）。入院时HbA1c<6.5%的患者与HbA1c=6.5%的患者相比,随着HbA1c含量的降低,预后不良的风险呈线性降低趋势;HbA1c>6.5%的患者与HbA1c=6.5%的患者相比,预后不良的风险更大,但差异无统计学意义。结论 入院时HbA1c水平升高与出血后90 d时预后不良风险有联系,HbA1c升高是脑出血预后不良的独立预测因子。     

新生儿骶尾部畸胎瘤病理与治疗探讨

目的 :分析新生儿骶尾部畸胎瘤的病理特点并探讨治疗要点。方法 :回顾分析 1990～ 2 0 0 3年间复旦大学附属儿科医院收治新生儿骶尾部畸胎瘤共 2 8例 ,手术标本送常规病理检验。结果 :男性 10例 ,女性 18例。I型 10例 ,II型 14例 ,III型 4例 ,瘤体在 10cm以上者 5例 ,其中 3例为巨大。平均手术年龄在 2 9± 2 2 .36d ,均在术中切除尾骨。 17例手术不需输血 ,其余输血 5 0～ 5 0 0ml不等。术后伤口感染 10例 (35 .71% )。术后病理 :良性 2 6例 ,其中含成熟神经组织 14例 ,恶性 3例 ,其中均含有未成熟神经组织。 2例良性畸胎瘤术后 1年复发 ,其中 1例复发为恶性。结论 :良性骶尾部畸胎瘤中 ,含神经组织成分可能是良性骶尾部畸胎瘤复发的危险因素之一。对新生儿巨大骶尾部畸胎瘤 ,术中控制髂内动脉 ,手术安全、术中出血少。瘤体的切除而影响了近肛门部皮瓣的血供可能是导致骶尾部畸胎瘤切口易感染的原因。骶尾部畸胎瘤伴发的隐性脊柱裂可能是导致术后肛门功能障碍的原因