Effect of local damages on the buckling behaviour of pyramidal truss core sandwich panels

Truss core sandwich panels have been widely investigated due to their superior mechanical performances. However, local defects or damages during preparation and service may reduce the strength significantly. The objective of this paper is to examine the imperfection sensitive of this kind of structures under in-plane compression. The elastic and plastic buckling behaviour of pyramidal truss core sandwich panels with local damages under in-plane compression are studied experimentally and numerically. Local damages including unbound nodes between lattice truss and the facesheet, missing lattice cells and holes in the facesheet are considered. In-plane compression tests of truss core sandwich panels with prefabricated local damages are conducted, and then a finite element model in conjunction with random number is developed to simulate the buckling behaviour of the panel with randomly distributed damages in a specific region. Experimental and numerical results show that, besides the damage extent, the location of unbound nodes and missing lattice cells have significant effect on the buckling strength of the pyramidal truss core sandwich panel. In addition, the local damage sensitiveness of sandwich panel with round holes in the facesheet is lower than that with square holes. (C) 2016 Published by Elsevier Ltd.</p

Baseline-free damage identification of metallic sandwich panels with truss core based on vibration characteristics

A baseline-free damage identification method is proposed to identify damages in metallic sandwich panels with truss core in the article. The method is based on flexibility matrix and gapped smoothing method, with damage index defined DIm. The weight coefficient m is introduced to consider the effect of damages on both low-order modes and high-order modes. Numerical simulations and experiments are conducted to evaluate the present method. Besides, damage index DIm* is also defined by processing DIm with Teager energy operator, and comparisons between DIm and DIm* are also carried out. Results show that the proposed method is effective in detecting single damage and multiple damages of the same or different extent. The weight coefficient m plays a very important role in identification of multiple damages of different styles. When comparing with DIm*, it is found that the present index DIm is better at suppressing the singularity caused by contact nodes and detecting of multiple damages which contain small or slight damages.</p

Promotion of proliferation of luminal B breast cancer cells by mesenchymal stem cells and its underlying molecular mechanisms

目的分析人脐带间充质干细胞(hUC-MSCs)对Luminal B型乳腺癌细胞生长增殖的影响,并初步探讨其可能的分子机理。方法绿色荧光蛋白(GFP)和荧光素酶共表达慢病毒感染人Luminal B型乳腺癌细胞BT474,并经嘌呤霉素筛选两周后,于荧光显微镜下观察GFP的表达情况,IVIS Kinetic成像系统拍照以观察和记录慢病毒感染后BT474细胞荧光素酶的表达情况;荧光显微镜下直接观察,结合MTS实验分析hUC-MSCs共培养或其浓缩上清处理对GFP和荧光素酶共表达BT474细胞生长增殖的影响;Western blot法检测hUC-MSCs浓缩上清处理对BT474细胞Akt和MAPK信号通路激活情况以及下游细胞周期调控蛋白Cyclin D1表达的影响;常规RT-PCR法检测hUC-MSCs中NRG-1、NRG-2、IGF-Ⅰ、IGF-Ⅱ和EGF等配体的表达。荧光素酶表达强度与细胞数量的相关性经由Excel软件行统计学分析,MTS实验数据则经由SPSS13.0统计软件行统计学分析。结果荧光显微镜和IVIS Kinetic成像系统的观察结果分别证实,GFP和荧光素酶经慢病毒载体系统的介导可在BT474细胞中成功地共表达,且荧光素酶的表达强度与细胞数量呈直线相关。MSCs共培养或其浓缩上清处理均可显著促进Luminal B型乳腺癌细胞BT474的生长增殖,其细胞存活比例分别为各自对照组的148.06%(P<0.005)和147.99%(P<0.001);MSCs浓缩上清处理同时激活BT474细胞内Akt和MAPK信号通路,并上调细胞周期调控蛋白Cyclin D1表达。此外,RT-PCR结果显示,hUC-MSCs中NRG-1和EGF的mRNAs水平呈高表达,而NRG-2、IGF-Ⅰ和IGF-Ⅱ等配体的mRNAs表达也可见。结论 MSCs可通过表达并分泌NRG-1等配体,从而激活Luminal B型乳腺癌细胞BT474的下游Akt和MAPK信号转导通路以上调细胞周期调控蛋白Cyclin D1的表达,进而促进其生长增殖。Objective To investigate the effect of human umbilical cord mesenchymal stem cells(hUC-MSCs) on proliferation of luminal B breast cancer cells and its underlying molecular mechanisms. Methods Human luminal B breast cancer cells BT474 were infected with GFP and luciferase co-expressing lentiviruses and then subjected for selection with Puromycin for 2 weeks. The expression of GFP and luciferase was detected by fluorescent microscopy and IVIS Kinetic image system, respectively. The effect of coculture or treatment with conditioned medium of hUCMSCs on proliferation of BT474 was analyzed with MTS assay. Western blot was carried out to detect the effect of treatment with conditioned medium of hUC-MSCs on the activation of both Akt and MAPK signalings in BT474, as well as the expression of downstream cell cycle regulator Cyclin D1. Regular RT-PCR was applied to analyze the mRNAs expression of ligands such as NRG-1, NRG-2, IGF-Ⅰ, IGF-Ⅱ, and EGF in hUC-MSCs. The correlation between relative luciferase activity and cell number was analyzed with Excel software, while MTS assay data was statistically analyzed with SPSS 13.0 software. Results The co-expression of GFP and luciferase in BT474 via lentiviral expression system was visualized by fluorescent microscopy and IVIS Kinetic image system. The linear correlation between relative luciferase activity and cell number was determined by curve fitting analysis. Coculture or treatment with conditioned medium of hUC-MSC significantly promoted the proliferation of BT474, with survival rates being 148.06 %(P < 0.005)and 147.99 %(P < 0.001)of control, respectively. In addition, treatment with conditioned medium of hUC-MSC was shown to induce activation of both Akt and MAPK signalings, which further upregulated the expression of Cyclin D1. Moreover, high mRNAs expression levels of both NRG-1 and EGF, as well as moderate mRNAs expression levels NRG-2, IGF-Ⅰ, and IGF-Ⅱ were showed by RT-PCR. Conclusion Our results here demonstrated that MSCs may promote the proliferation of luminal B breast cancer cells through paracrine of ligands such as NRG-1, which in turn results in the activation of both Akt and MAPK signalings and upregulation of the expression of Cyclin D1.国家自然科学基金面上项目(81272922);; 福建省自然科学基金面上项目(2016J01577);; 福州总医院院内课题国际合作研究专项(2015G01

受療者からみた明治国際医療大学附属鍼灸センター利用に関する評価

近年,良質な医療が求められ,良質な医療の実現には医療を提供する治療者の評価だけでなく,治療施設の環境や患者と施術者間のコミュケーション(対応)なども重要視されている.これまでに明治国際医療大学附属鍼灸センターの受療者から治療室と待合室の環境や治療,スタッフの接遇などの評価を行ったことはない.そこで,これらの項目のアンケート調査を行い,問題点を調査することとした.調査対象は平成19年8月6日から8月10日までの5日間に附属鍼灸センターを受診したすべての患者とした.調査は「明治国際医療大学附属鍼灸センターのご利用に関するアンケート調査」とし,調査項目は性別と年齢,受療者区分(一般,老人会,本学職員,本学学生),通院歴,治療室の環境,治療,スタッフの対応・接遇,待合室の環境,診療開設日に関する項目の合計22とした.その結果,治療室と待合室の環境や治療,スタッフの接遇について高い評価が得られた.しかし,問題点としてトイレの手すりの必要性や治療までの待ち時間の長さが挙げられ,今後,トイレの手すりの取り付けや待ち時間を軽減させるための予約制の導入などを考える必要がある.(著者抄録

基于肠肝轴研究栀子苷对非酒精性脂肪性肝炎大鼠的影响

目的观察栀子苷对非酒精性脂肪性肝炎(non-alcoholic steatohepatitis,NASH)大鼠的影响,并基于肠肝轴探讨栀子苷防治NASH的作用机制。方法将35只大鼠按随机数字表法分为5组,每组7只。即正常组、模型组、栀子苷组、盐酸吡格列酮组及培菲康组。除正常组外,其余28只大鼠采用高脂饮食16周建立大鼠NASH模型,在造模第9周开始给药,共治疗8周。第16周末经腹主动脉取血,生化法检测肝组织甘油三酯(TG)水平,苏木精-伊红(HE)染色观察肝组织、肠组织病理学变化。ELISA法检测肝组织白细胞介素(IL)-1β、IL-6、肿瘤坏死因子-α(TNF-α)等炎症因子的表达水平。终点显色法检测血浆内毒素(LPS)含量。结果与正常组比较,模型组大鼠的肝组织显示出典型的NASH组织学特征,经栀子苷干预后,肝细胞脂肪变性、炎症浸润较模型组减轻。与正常组比较,模型组大鼠肠上皮细胞少量脱落,肠黏膜机械屏障受损。经栀子苷干预后,回肠黏膜结构完整,未见明显肠上皮细胞脱落。与正常组比较,模型组大鼠脂肪重量、肝湿重、肝指数、肝脏TG含量、血浆LPS水平、肝组织IL-1β、IL-6、TNF-α等炎症因子水平均有不同程度增高(P<0.01)。经干预后,栀子苷组大鼠脂肪重量、肝湿重、肝指数、肝脏TG含量、血浆LPS水平、肝组织IL-1β、IL-6、TNF-α等炎症因子水平均较模型组有不同程度的下降(P<0.05,P<0.01)。结论栀子苷能明显改善大鼠肠黏膜组织结构,保持肠黏膜屏障的完整性,显著降低血浆LPS水平,显著降低NASH大鼠肝组织IL-1β、IL-6、TNF-α等炎症因子的表达。提示栀子苷治疗NASH的作用机制与调节肠肝轴、改善肠黏膜屏障、减少内源性LPS产生、降低炎症因子表达有关。国家自然科学基金资助项目(No.81673660)2017、2018厦门大学大学生创新创业训练课题(No.2017X0547; No.201810384230

基于肠肝轴研究栀子苷对非酒精性脂肪性肝炎大鼠的影响

目的 观察栀子苷对非酒精性脂肪性肝炎(non-alcoholic steatohepatitis,NASH)大鼠的影响,并基于肠肝轴探讨栀子苷防治NASH的作用机制。方法 将35只大鼠按随机数字表法分为5组,每组7只。即正常组、模型组、栀子苷组、盐酸吡格列酮组及培菲康组。除正常组外,其余28只大鼠采用高脂饮食16周建立大鼠NASH模型,在造模第9周开始给药,共治疗8周。第16周末经腹主动脉取血,生化法检测肝组织甘油三酯(TG)水平,苏木精-伊红(HE)染色观察肝组织、肠组织病理学变化。ELISA法检测肝组织白细胞介素(IL)-1β、IL-6、肿瘤坏死因子-α(TNF-α)等炎症因子的表达水平。终点显色法检测血浆内毒素(LPS)含量。结果与正常组比较,模型组大鼠的肝组织显示出典型的NASH组织学特征,经栀子苷干预后,肝细胞脂肪变性、炎症浸润较模型组减轻。与正常组比较,模型组大鼠肠上皮细胞少量脱落,肠黏膜机械屏障受损。经栀子苷干预后,回肠黏膜结构完整,未见明显肠上皮细胞脱落。与正常组比较,模型组大鼠脂肪重量、肝湿重、肝指数、肝脏TG含量、血浆LPS水平、肝组织IL-1β、IL-6、TNF-α等炎症因子水平均有不同程度增高(P<0.01)。经干预后,栀子苷组大鼠脂肪重量、肝湿重、肝指数、肝脏TG含量、血浆LPS水平、肝组织IL-1β、IL-6、TNF-α等炎症因子水平均较模型组有不同程度的下降(P<0.05,P<0. 01)。结论栀子苷能明显改善大鼠肠黏膜组织结构,保持肠黏膜屏障的完整性,显著降低血浆LPS水平,显著降低NASH大鼠肝组织IL-1β、IL-6、TNF-α等炎症因子的表达。提示栀子苷治疗NASH的作用机制与调节肠肝轴、改善肠黏膜屏障、减少内源性LPS产生、降低炎症因子表达有关