Development and Optimization of Broadband Acoustic Metamaterial Absorber Based on Parallel–Connection Square Helmholtz Resonators

An acoustic metamaterial absorber of parallel–connection square Helmholtz resonators is proposed in this study, and its sound absorption coefficients are optimized to reduce the noise for the given conditions in the factory. A two–dimensional equivalent simulation model is built to obtain the initial value of parameters and a three–dimensional finite element model is constructed to simulate the sound absorption performance of the metamaterial cell, which aims to improve the research efficiency. The optimal parameters of metamaterial cells are obtained through the particle swarm optimization algorithm, and its effectiveness and accuracy are validated through preparing the experimental sample using 3D printing and measuring the sound absorption coefficient by the standing wave tube detection. The consistency between the experimental data and simulation data verifies feasibility of the proposed optimization method and usefulness of the developed acoustic metamaterial absorber, and the desired sound absorption performances for given conditions are achieved. The experimental results prove that parallel–connection square Helmholtz resonators can achieve an adjustable frequency spectrum for the low frequency noise control by parameter optimization, which is propitious to promote its application in reducing the noise in the factory.     

改良Kessler法治疗跟腱开放性断裂

目的总结24例采用改良Kessler法治疗跟腱开放性断裂,观察疗效。方法对采用改良Kessler法急诊手术治疗跟腱开放性断裂且获得有效随访24例患者的临床疗效进行回顾性分析。结果用Amer-Lindholm疗效评定标准进行评分,本组优18例,良4例,优良率91.7%。结论改良Kessler法是治疗跟腱开放性断裂的一种疗效满意的方法。     

Fraxinol attenuates LPS-induced acute lung injury by equilibrating ACE-Ang II-AT1R and ACE2-Ang (1-7)-Mas and inhibiting NLRP3

ContextAcute lung injury (ALI) is a serious heterogenous pulmonary disorder. Fraxinol was selected for this study since it is a simple coumarin compound, not previously investigated in ALI.ObjectivesThis study investigates the ALI therapeutic effect and mechanisms of fraxinol.Materials and methodsMale BALB/c mice were treated with fraxinol (20, 40, and 80 mg/kg) following intranasal injection of lipopolysaccharide (LPS; 10 μg in 50 μL). The mice in control group were intratracheally injected with 50 μL phosphate buffered saline (PBS). Raw264.7 cells were treated with fraxinol by 100 ng/mL LPS for 6 h, then treated by different concentrations of fraxinol (5, 10, and 25 μM) for 48 h. Cells in control group were treated with PBS.ResultsFraxinol with doses of 20, 40, and 80 mg/kg significantly attenuated LPS-induced lung injury in mice (lung injury score, 10.4, 31.2, 50.3%). Fraxinol attenuated the apoptosis and nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing-3 (NLRP3) activation induced by LPS (apoptosis, 18.3, 30.2, 55.6%; NLRP3, 30.0, 47.7, 63.6%). The anti-apoptosis and anti-inflammation effects of fraxinol were also confirmed in Raw264.7 cells (apoptosis, 38.8, 55.3, 68.9%; NLRP3, 20.6, 55.7, 73.9%).Discussion and conclusionThe anti-ALI effects of fraxinol maybe by equilibrating ACE-Ang II-AT1R and ACE2-Ang (1-7)-Mas axis and inhibiting NLRP3 inflammasome. Our research provides a candidate drug in the treatment of ALI.     

人牙髓组织缺氧耐受机制的初步研究

目的：研究缺氧诱导因子-1α（Hypoxia inducible factor-1α,HIF-1α）和环氧化酶-2（Cyclooxygenase-2,COX-2）在人正常牙髓和炎症牙髓中的免疫定位,探讨缺氧耐受机制在牙髓炎病程中和牙髓自身修复过程中的作用和意义。方法：通过SP法对第1组10例健康牙髓、第2组10例深龋（有过敏症状但无牙髓炎症状）患牙牙髓、第3组15例急性牙髓炎牙髓和第4组15例慢性牙髓炎牙髓进行免疫组化染色,分别对HIF-1α和COX-2进行免疫定位和半定量分析。结果：①HlF-1α在第1组健康牙髓和第2组深龋牙髓标本中,只有个别标本呈弱阳性表达,二组问无显著性差异（P〉0．05）,但对比其它二组标本则有显著性差异（P〈0．001）：第3组急性牙髓炎牙髓呈强阳性表达,第四组慢性牙髓炎牙髓亦呈阳性染色与第3组比较总体偏弱,有显著性差异（P〈0．05）。②COX-2在第1组牙髓中个别标本呈弱阳性表达;第2组标本绝大多数染色呈弱阳性,与第1组比较有显著性差异（P〈0.05）;第3组标本染色均呈强阳性,与前两组比较有显著差异性伊值分别为P〈0.001,P〈0．05）;第4组标本亦呈阳性染色,总体上阳性程度明显高于第l组（P〈0．001）,高于第2组（P〈0．05）,弱于第3组（P〈0．05）。HIF-1α与COX-2的表达关系主要在第3组和第4组牙髓标本中体现明显,在第3组二者的变化大致呈平行关系;在第4组基本呈反向变化关系。结论：HIF-1α和COX-2在牙髓炎病程中可能发挥着重要的生理和病理作用,在牙髓炎进程中和牙髓自身修复过程中可能存在着缺氧环境和缺氧耐受机制。     

一起副溶血性弧菌引起旅游者食物中毒的调查分析

目的 查明一起旅游者食物中毒发生原因,提出预防和控制措施,保障人们的身体健康.方法 流行病学和现场卫生学调查,临床表现分析和相应的样品检测.结果 从患者的肛拭子、厨房的涂抹拭子(刀、砧板、抹布)和腌卤血蚶中检出生物学特性一致的副溶血性弧菌.结论 这是一起食用被副溶血性弧菌污染的海产品而引起的旅游者食物中毒事件.因此加强对餐饮行业及从业人员的卫生监督和培训,引导旅游者选择卫生条件好的餐饮单位以及正确的饮食方法,是减少类似食物中毒事件的关键.     

外伤性张力性气颅的诊断和治疗

目的:探讨外伤性张力性气颅的诊断和治疗方法,提高临床治疗水平.方法:按发病急缓、积气部位以及是否合并颅内严重损伤将患者分为三组,并依此分别采用保守治疗(9例)、钻孔引流(8例)和开颅手术(8例)进行治疗.结果:保守组和引流组分别有8例和7例在3周内积气消失,另各有1例无效者在2周后中转鼻内镜颅底修补痊愈;开颅组8例经排空积气、清创并修复颅底缺损后治愈.无术后颅内感染、脑脊液漏、脑膜脑膨出及手术死亡等发生.结论:按发病急缓、积气部位以及是否合并颅内严重损伤来对外伤性张力性气颅进行诊断和分组,并依此选择保守治疗、钻孔引流和开颅或鼻内镜手术进行治疗能获得良好治疗结果.     

抑制Blimp-1表达导致浆细胞去分化

目的探讨转录因子Bhmp-1在浆细胞发育中的作用。方法应用慢病毒载体稳定表达针对Blimp-1的siRNA,抑制骨髓瘤细胞J558L中Blimp-1的表达。采用免疫荧光及流式细胞技术观察Blimp-1抑制前后细胞的免疫表型变化,半定量RT-PCR检测XBP-1、J-chain、c-myc、BCMA的变化。结果Blimp-1抑制后,浆细胞表面标志CD138表达显著下降,B淋巴细胞免疫标志CD19表达增加。同时,与浆细胞功能及存活密切相关的XBP-1、J-chain、BCMA基因表达下降,而促进B淋巴细胞增殖发育的c-myc表达上升。结论浆细胞中Blimp-1被抑制后,浆细胞发育程序出现再编程,发生了去分化现象,返回到更早期的发育阶段,提示Blimp-1特异性shRNA有可能用于浆细胞相关疾病的治疗。     

星点设计-效应面法优化炒茺蔚子炮制工艺

目的:利用星点设计-效应面法对炒茺蔚子的炮制工艺进行优化,为炒茺蔚子的规范化生产提供依据。方法:采用清炒法,以炮制温度、炮制时间、炒药机转速为自变量,总生物碱、盐酸水苏碱、水溶性浸出物、醇溶性浸出物质量分数为评价指标,对自变量各水平进行多元回归拟合,利用效应面法筛选最佳炮制工艺并进行预测分析。采用UV测定总生物碱的含量,检测波长520 nm;采用高效液相色谱仪-蒸发光散射法测定盐酸水苏碱的含量,流动相乙腈-水(60∶40),流速0.5 m L·min~(-1),漂移管温度70℃。结果:三项式拟合复合相关系数较高。最佳炮制工艺为炮制温度219℃,炮制时间2 min,炒药机转速14 r·min~(-1)。总生物碱、盐酸水苏碱、水溶性浸出物、醇溶性浸出物质量分数的平均值分别为9.82,2.50,86.16,193.28 mg·g~(-1),综合评分与三项式拟合方程预测值偏差0.87%。结论:利用星点设计-效应面法优化炒茺蔚子炮制工艺的方法简便且预测性良好,适用于炒茺蔚子的规范化生产。     

凝胶材料配比对丁香罗勒油透皮凝胶体外透皮性能的影响

目的:探索凝胶材料配比对丁香罗勒油透皮凝胶体外透皮性能的影响。方法:以CMC-Na和PVA为辅料,制备丁香罗勒油透皮剂。采用改良Franz扩散池,以鼠背皮肤为屏障进行经皮渗透试验,以丁香酚含量为指标,通过气相色谱法检测丁香罗勒油的经皮渗透量。结果:CMC-Na和PVA总量对丁香罗勒油透皮能力有较大影响,以25%为最佳;CMC-Na和PVA的比例对丁香罗勒油透皮能力无影响,最佳比例4∶2。结论:丁香罗勒油透皮凝胶可极大地提高丁香罗勒油的药效。