6-姜烯酚诱导人结肠癌细胞HT29凋亡及与VEGFR2表达变化的关系

本文通过研究不同浓度6-姜烯酚诱导结肠癌细胞HT 29凋亡及与VEGFR2(血管内皮细胞受体2)不同表达之间的关系,以探讨其可能的抑制结直肠肿瘤相关机制。通过应用不同浓度6-姜烯酚(0、10、20和40μM)分别对体外细胞实验培养的HT29细胞株进行诱导处理24 h,相差倒置荧光显微镜观察细胞形态变化,CCK8(Cell Counting Kit-8)法测定药物诱导后细胞抑制率,Annexin V-FITC/PI流式细胞术检测不同浓度药物干预后细胞凋亡率及凋亡周期变化,最后用Western-blot检测分析VEGFR2蛋白不同表达变化。结果显示,与对照组相比,6-姜烯酚可呈浓度依赖性地诱导HT29凋亡,并使细胞周期G0/G1期细胞数由49.48%下降到24.39%和17.18%,而G2/M期细胞数由3.44%增加到34.78%和49.54%,进而将细胞周期阻滞在G2/M期,抑制细胞增殖,而且还不同程度地抑制了VEGFR2表达(p0.05)。结果表明,6-姜烯酚主要是通过诱导HT29凋亡进而起到抑制肿瘤细胞增殖的作用,这可能与不同程度抑制VEGFR2有关。     

Piezoelectric Microvibration Mitigates Estrogen Loss-Induced Osteoporosis and Promotes Piezo1, MicroRNA-29a,and Wnt3a Signaling in Osteoblasts

Biophysical stimulation alters bone-forming cell activity, bone formation and remodeling. The effect of piezoelectric microvibration stimulation (PMVS) intervention on osteoporosis development remains uncertain. We investigated whether 60 Hz, 120 Hz, and 180 Hz PMVS (0.05 g, 20 min/stimulation, 3 stimulations/week for 4 consecutive weeks) intervention affected bone integrity in ovariectomized (OVX) mice or osteoblastic activity. PMVS (120 Hz)-treated OVX mice developed fewer osteoporosis conditions, including bone mineral density loss and trabecular microstructure deterioration together with decreased serum resorption marker CTX-1 levels, as compared to control OVX animals. The biomechanical strength of skeletal tissue was improved upon 120 Hz PMVS intervention. This intervention compromised OVX-induced sparse trabecular bone morphology, osteoblast loss, osteoclast overburden, and osteoclast-promoting cytokine RANKL immunostaining and reversed osteoclast inhibitor OPG immunoreactivity. Osteoblasts in OVX mice upon PMVS intervention showed strong Wnt3a immunoreaction and weak Wnt inhibitor Dkk1 immunostaining. In vitro, PMVS reversed OVX-induced loss in von Kossa-stained mineralized nodule formation, Runx2, and osteocalcin expression in primary bone-marrow stromal cells. PMVS also promoted mechanoreceptor Piezo1 expression together with increased microRNA-29a and Wnt3a expression, whereas Dkk1 rather than SOST expression was repressed in MC3T3-E1 osteoblasts. Taken together, PMVS intervention promoted Piezo1, miR-29a, and Wnt signaling to upregulate osteogenic activity and repressed osteoclastic bone resorption, delaying estrogen deficiency-induced loss in bone mass and microstructure. This study highlights a new biophysical remedy for osteoporosis.     

二维电离室矩阵在放疗的质量保证体系中的应用

肿瘤的放射治疗中,为了检测治疗设备的性能以及确保放疗计划实施的可靠性和准确性,必须具备完善的质量保证体系（Quality Assurance,QA）. 本文研究将德国PTW公司研发的二维电离室矩阵Seven29应用到放疗的日常QA过程中,使用Seven29和与之配套的八角体模或平板体模来测量剂量分布图,并与治疗计划系统计算出来的剂量分布图进行比较. 对治疗设备每月的QA,最重要的项目是检测射线性能的连续性,检测方法是对连续两个月机器性能的参数进行比较. 采用PTW公司的软件VeriSoft和MultiCheck进行数据分析,经大量的实验验证和比较,结果表明二维电离室矩阵是剂量测量和分析的有效工具,其精度高、可靠性强、使用方便,是实现无胶片化和无纸化放疗体系的重要组成部分.     

Vitamin D Reverses Disruption of Gut Epithelial Barrier Function Caused by Campylobacter jejuni

Infections by the zoonotic foodborne bacterium Campylobacter jejuni (C. jejuni) are among the most frequent causes of bacterial gastroenteritis worldwide. The aim was to evaluate the relationship between epithelial barrier disruption, mucosal immune activation, and vitamin D (VD) treatment during C. jejuni infection, using intestinal epithelial cells and mouse models focused on the interaction of C. jejuni with the VD signaling pathway and VD treatment to improve C. jejuni-induced barrier dysfunction. Our RNA-Seq data from campylobacteriosis patients demonstrate inhibition of VD receptor (VDR) downstream targets, consistent with suppression of immune function. Barrier-preserving effects of VD addition were identified in C. jejuni-infected epithelial cells and IL-10^−/− mice. Furthermore, interference of C. jejuni with the VDR pathway was shown via VDR/retinoid X receptor (RXR) interaction. Paracellular leakiness of infected epithelia correlated with tight junction (TJ) protein redistribution off the TJ domain and apoptosis induction. Supplementation with VD reversed barrier impairment and prevented inhibition of the VDR pathway, as shown by restoration of transepithelial electrical resistance and fluorescein (332 Da) permeability. We conclude that VD treatment restores gut epithelial barrier functionality and decreases bacterial transmigration and might, therefore, be a promising compound for C. jejuni treatment in humans and animals.     

重卡正面碰撞强度试验的有限元分析

依据ECE29法规,对重卡驾驶室正面碰撞强度试验进行了有限元仿真。当摆锤正面撞击后,测量结果表明驾驶室方向盘外延到座椅的x向距离大于法规中人胸部厚度,证明了驾驶室具有足够的生存空间。     

Influences of electric pulse on solidification structure of LM-29 Al-Si alloy

The metallographic structure of LM-29 aluminum-silicon alloy modified by electric pulse treatment has been investigated and compared with those untreated. The solidification structure of LM-29 alloy has been analyzed by means of M1AP3 Quantimet image processing and analysis system, and then the solidification process has been analyzed by means of differential scanning calorimetry (DSC). The results indicate that the primary silicon phase was refined remarkably by electric pulse while the tensile strength and elongation properties increased accordingly. Electric pulse treatment can also increase the binding power between silicon clusters and alloy melt matrix, as a result, the precipitation of primary silicon phase is suppressed to meet the demand of supercooling degree for nucleating, correspondingly. The electric pulse modification has great influence on the size of silicon atomic cluster as well as its distribution in the melt, subsequently, leads to the refinement of solidification structure.     

29Si固体核磁共振技术在C-S-H凝胶中的应用进展

C-S-H凝胶作为硅酸盐水泥最主要的水化产物,是影响水泥混凝土行业工程质量的重要因素.本文围绕29Si固体核磁共振技术(29Si NMR)在硅酸盐水泥水化产物应用展开,从水化硅酸钙晶型、C-S-H聚合机理、钙硅比、机械力活化作用、矿物掺合料对C-S-H影响等几方面阐述29Si NMR在硅酸盐水泥水化产物C-S-H凝胶中的应用,提出了利用29Si NMR分析硅酸盐水泥水化产物存在的问题,并展望了29Si NMR在水泥水化领域的发展趋势.     

Design of flowing liquid lithium device for HT-7 tokamak

Lithium is a very attractive element due to its very low radiation power, strong H retention as well as strong O getter activity. Flowing liquid lithium (FLiLi) device, to be used as a plasma-facing limiters, has been designed and will be tested in HT-7 tokamak. It is mainly composed of distributor, guide plate, collector, and heater as well as cooling loop. The heater uses heater strip and cooling loop design, to control the temperature of lithium on the guide plate ranging from 200 °C to 400 °C. The distributor attached to feeding pipe, distributes liquid lithium (LiLi) flowing on the guide plate. The collector was designed to reclaim the superfluous LiLi and transport it out of device.The paper focuses on the design of flowing liquid lithium device. In addition to the process of design, thermal analysis has been carried out using finite element method (FEM) for optimizing the structure of heater and cooling loop and results of analysis are presented.     

Influence of template on Si distribution of SAPO-11 and their performance for n-paraffin isomerization

SAPO-11 molecular sieves were synthesized using single agent (i.e. diethylamine (DEA), di-iso-propylamine (DIPA) and di-n-propylamine (DPA)) or a mixture of DEA and DIPA (named DEPA) as the template under hydrothermal conditions. XRD indicated that the directing effect of different templates for AEL structure decreased in the order of DEPA > DPA > DIPA > DEA. ²⁹Si MAS NMR showed that although all SAPO-11 samples synthesized at same Si content, that prepared with the mixed template contained more Si (4Al) sites, whereas Si (nAl, 4-nSi, 0 < n < 4) environments were predominant in the samples synthesized with single template. The results indicated that the mixed template led to a better Si dispersion and then increased the number of total acid sites of SAPO-11. In the isomerization of n-tetradecane over different Pt/SAPO-11 catalysts, the sample prepared with DEPA showed high catalytic activity and selectivity for i-C₁₄, which were related to the most abundant weak acid sites of the sample.