Effect of ligand troglitazone on peroxisome proliferator-activated receptor γ expression and cellular growth in human colon cancer cells

AIM: To investigate the effect of troglitazone on pe- roxisome proliferator-activated receptor γ (PPARγ) expression and cellular growth in human colon cancer HCT-116 and HCT-15 cells and to explore the related molecular mechanism. METHODS: Human colon cancer HCT-116 and HCT-15 cells cultured in vitro were treated with troglitazone. Reverse transcription-polymerase chain reaction (RT-PCR) and Western blot were employed to detect the effect of troglitazone on PPARγ expression. The proliferative activity was determined by MTT assay, cell cycle and apoptosis were detected by ? ow cytometry. Apoptosis- related genes, cell cycle regulatory genes and p53 were examined by RT-PCR and Western blot respectively. RESULTS: The expression of PPARγ in colon cancer HCT-116 and HCT-15 cells was up-regulated by troglitazone. Troglitazone inhibited proliferation, induced apoptosis and cell cycle G1 arrest in colon cancer cells. Troglitazone induced p53 expression in HCT-116 cells, but not in HCT-15 cells. The down-regulation of survivin and bcl-2 was found in both cell lines and up-regulation of bax was found only in HCT-116 cells, being consistent with growth inhibition in HCT-116 cells but not in HCT-15 cells. Troglitazone increased expression of p21WAF1/CIP1 (p21), p27KIP1 (p27) and reduced cyclin D1 in HCT-116 cells while only a minor decrease of cyclin D1 was found in HCT-15 cells. CONCLUSION: Troglitazone is an inductor of PPARγin colon cancer cells and inhibits PPARγ-dependently proliferation, which may attribute to cell cycle G1 arrest and apoptosis in colon cancer cells. Troglitazone may induce p53-independent apoptosis and p53- dependent expression of p21 and p27. Depending on cell background, different activation pathways may exist in colon cancer cells.

A continuous-discontinuous cellular automaton method for cracks growth and coalescence in brittle material

A method of continuous-discontinuous cellular automaton for modeling the growth and coalescence of multiple cracks in brittle material is presented. The method uses the level set to track arbitrary discontinuities, and calculation grids are independent of the discontinuities and no remeshing are required with the crack growing. Based on Grif- fith fracture theory and Mohr-Coulumb criterion, a mixed fracture criterion for multiple cracks growth in brittle mate- rial is proposed. The method treats the junction and coales- cence of multiple cracks, and junction criterion and coales- cence criterion for brittle material are given, too. Besides, in order to overcome the tracking error in the level set ap- proximation for crack junction and coalescence, a dichotomy searching algorithm is proposed. Introduced the above the- ories into continuous-discontinuous cellular automaton, the present method can be applied to solving multiple crack growth in brittle material, and only cell stiffness is needed and no assembled global stiffness is needed. Some numerical examples are given to shown that the present method is efficient and accurate for crack junction, coalescence and percolation problems.

Modeling of aluminum-silicon irregular eutectic growth by cellular automaton model

Due to the extensive application of Al-Si alloys in the automotive and aerospace industries as structural components, an understanding of their microstructural formation, such as dendrite and(Al+Si) eutectic, is of great importance to control the desirable microstructure, so as to modify the performance of castings. Since previous major themes of microstructural simulation are dendrite and regular eutectic growth, few efforts have been paid to simulate the irregular eutectic growth. Therefore, a multiphase cellular automaton(CA) model is developed and applied to simulate the time-dependent Al-Si irregular eutectic growth. Prior to model establishment, related experiments were carried out to investigate the influence of cooling rate and Sr modification on the growth of eutectic Si. This CA model incorporates several aspects, including growth algorithms and nucleation criterion, to achieve the competitive and cooperative growth mechanism for nonfaceted-faceted Al-Si irregular eutectic. The growth kinetics considers thermal undercooling, constitutional undercooling, and curvature undercooling, as well as the anisotropic characteristic of eutectic Si growth. The capturing rule takes into account the effects of modification on the silicon growth behaviors.The simulated results indicate that for unmodified alloy, the higher eutectic undercooling results in the higher eutectic growth velocity, and a more refined eutectic microstructure as well as narrower eutectic lamellar spacing. For modified alloy, the eutectic silicon tends to be obvious fibrous morphology and the morphology of eutectic Si is determined by both chemical modifier and cooling rate. The predicted microstructure of Al-7Si alloy under different solidification conditions shows that this proposed model can successfully reproduce both dendrite and eutectic microstructures.

Growth of a Cellular/Dendritic Array

This paper describes a time dependent numerical model for the steady and non-steady growthof a cellular/dendritic array in a moving linear temperature field. The model gives fully selfconsistent solutions for axisymmetric interface shapes, predicts cellular and dendritic spacings,undercoolings and the transition between structures. An important feature of the model is thatthe spacing selection mechanism has been treated. The model predicts two different dendriticgrowth regions. One occurs at low dimensionless velocities where the dendrite array is uniform:a small stable range of spacings is predicted and the prediction agrees very well with existing experiments. The other occurs at high dimensionless velocities where the dendrite array is irregular, its minimum spacing is inversely proportional to velocity Experiment was carried out to verify the prediction. The irregular dendrite array was observed and the measured minimum spacing fitted extremely well with the prediction. By fitting the numerical results. Relatively simple analytic expressions are obtained which provide an insight into the cellular and dendritic growth processes and are useful for comparing theory with experiment.

基于热力学函数的纳米晶粒长大Cellular Automaton仿真研究

基于纳米晶热力学特性表征函数,将纳米晶热力学性质对晶界迁移的影响引入Cellular Automaton算法,对纳米晶粒长大行为进行了定量化和可视化的仿真研究.模拟结果表明,纳米晶粒长大的动力学与传统粗晶材料不同,在恒温条件下,纳米晶粒的长大指数n不是常数(传统粗晶材料的晶粒长大指数n=2为常数),随纳米晶粒长大过程的进行,n值从1.70至6.59发生变化.作为纳米晶粒长大的驱动力,纳米晶界的过剩自由能与纳米晶粒尺寸的变化直接相关.由于纳米晶材料强烈的小尺寸效应,纳米晶组织的热力学性质较大地影响纳米晶界的结构和能量状态,从而影响纳米晶粒长大的动力学特征.因此,只有结合纳米晶热力学特性的仿真研究才能获得对纳米晶粒长大行为本质性的认识.

用Cellular Automaton模型方法模拟二元合金多晶粒枝晶生长

研究并针对CellularAutomaton凝固组织模拟方法的物理本质、数值计算方法以及在凝固微观组织模拟中的应用进行了探索。并利用CellularAutomaton凝固组织模拟方法,求解了Al4.5Cu等轴晶多个枝晶同时生长过程。模拟结果和试验结果吻合很好。

INTERFACE MORPHOLOGIES AND MICROSTRUCTURES DURING DENDRITE-TO-CELL TRANSITION AT HIGH GROWTH RATE

The interface morphologies and microstruetures of the directionally solidified Ni-5wt-% Cu alloy during dendrite-to-cell transition at high growth rates have been investigated with a newly developed apparatus for unidirectional solidification with the temperature gradient at the solid/liquid interface higher than 1000 K/cm.The results show that in the vicinity of dendrite-to-cell transition point,the well developed sidebranches become shrivelled with the increase of growth rate and disappear at the dendrite-to-cell transition,and the primary spacing decreases simultaneously.Moreover,the length of mushy zone decreases greatly dur- ing the dendrite-to-cell transition.Cells obtained at high growth rates have very similar morphologies to those at low growth rates,but with much smaller cell spacings and unsmoothed cell walls which may be attributed to the different stability conditions of the cell walls at low and high growth rates respectively.

成骨细胞代谢重编程与早期肾性骨病发生发展的研究进展

慢性肾脏病矿物质和骨骼疾病(CKD-MBD)对患者的生活质量、住院率和骨折风险有直接影响。近年来成骨细胞及骨细胞成为CKD-MBD病理生理学研究的中心,成骨细胞通过合成成纤维细胞生长因子23(FGF-23)、硬化素等,与其他器官相互作用,使骨骼成为内分泌器官。因此,成骨细胞分化失调是慢性肾脏病发病过程中重要的早期事件。本文系统讨论了成骨细胞的代谢途径及早期CKD-MBD病理状态下成骨细胞代谢重编程改变的相关机制,表明Wnt家族分泌蛋白/β-连环蛋白(Wnt/β-catenin)、FGF-23、尿毒症毒素、代谢性酸中毒等信号通路及代谢物异常可改变成骨细胞代谢活性,引起成骨谱系成熟障碍,进而影响骨重塑,对于解释肾性骨病病理改变及临床治疗方案提供新思路。

采用Cellular Automaton法模拟铝合金的微观组织

采用 Cellular Automaton微观模型 ,并与宏观的传热计算相结合 ,对砂型铸造铝合金铸件的凝固组织形成进行了模拟。在模拟过程中 ,采用连续形核的方法处理液态金属的异质形核现象。通过高斯分布函数描述形核质点密度随温度的分布关系 ,在给定过冷度时对分布函数求积分可得该时刻的形核密度。晶粒生长模型则考虑枝晶尖端生长动力学和择优生长方向〈1 0 0〉晶向。模拟计算结果表明 ,在冷却速度不变的情况下 ,随着形核分布参数ΔTN 增加 ,所得到的晶粒尺寸增大。

光照强度对原位藻细胞组分生长及生物柴油性能的影响

为了探究光强对污水原位藻生长、光合活性及藻细胞胞内/外组分的影响,对比研究了2个光强(54μmol/(m^(2)·s)、1000μmol/(m^(2)·s))下原位藻细胞数、藻液pH、叶绿素含量及光合作用参数(F_(v)/F_(m)、rETR)的变化,以及胞外聚合物、胞内蛋白质、多糖和脂肪酸含量等原位藻细胞内/外组分的响应特性。结果表明:与低光强相比,高光强下原位藻生物量下降47.63%,藻液pH由6.60快速提升至11.36,叶绿素浓度仅为1.66 mg/L,光合活性下降,生长被显著抑制;胞内蛋白质和多糖含量分别下降29.19%和16.23%,而胞外聚合物含量显著提高58.14%;脂肪酸含量上升(440.548 mg/L)且成分比例发生变化,高光强下培养的原位藻生物柴油具有较好的氧化稳定性能、亲水性能、燃烧性能、高温保护性能,而低温流动性及能量则略逊于低光强组。

安罗替尼与紫杉醇联合顺铂化疗方案治疗晚期非小细胞肺癌的效果

目的 探讨安罗替尼与紫杉醇联合顺铂化疗方案在晚期非小细胞肺癌(NSCLC)患者治疗中的应用效果。方法 选取信阳市中心医院2019年2月至2021年2月信阳市中心医院62例NSCLC患者,按照随机数字表法分为两组,各31例。对照组接受紫杉醇联合顺铂方案治疗,研究组在对照组的基础上接受安罗替尼治疗。比较两组近期疗效、治疗前后肿瘤细胞生长因子[基质金属蛋白酶-9(MMP-9)、血管内皮生长因子(VEGF)、碱性成纤维细胞生长因子(BFGF)]水平、细胞免疫功能[T淋巴细胞(CD3^(+)、CD4^(+)、CD8^(+))、CD4^(+)/CD8^(+)]、生存期、生活质量及毒副反应。结果 研究组疾病缓解率、疾病控制率高于对照组(P<0.05);治疗后,研究组CD3^(+)、CD4^(+)、CD4^(+)/CD8^(+)较对照组升高,MMP-9、VEGF、BFGF、CD8^(+)较对照组降低(P<0.05);研究组中位无进展生存期、总生存期长于对照组(P<0.05);治疗后研究组功能评价系统-肺癌模块评分高于对照组,欧洲癌症研究与治疗组织生命质量量表评分低于对照组(P<0.05);两组毒副反应发生率差异无统计学意义(P>0.05)。结论 安罗替尼与紫杉醇联合顺铂化疗方案治疗晚期NSCLC效果确切,可抑制肿瘤细胞生长,减轻免疫功能损伤,延长患者生存期,提高生活质量,且安全性较好。

贝伐珠单抗联合奥希替尼对EGFR-T790M突变晚期NSCLC患者细胞免疫功能及血管相关生长因子的影响

目的探讨贝伐珠单抗联合奥希替尼治疗表皮生长因子受体(EGFR)-T790M晚期突变非小细胞肺癌(NSCLC)的临床疗效及可能作用机制。方法回顾性分析2020年1月至2022年5月接受治疗的EGFR-T790M突变晚期NSCLC患者88例,根据治疗方法分为观察组46例和对照组42例。对照组给予奥希替尼治疗,观察组给予贝伐珠单抗联合奥希替尼治疗,比较2组细胞免疫功能、血管相关生长因子、不良反应、近期疗效等。结果观察组缓解率60.87%、疾病控制率86.96%高于对照组的38.10%、66.67%(χ^(2)=4.555,5.147,P<0.05)。CD3^(+)、CD4^(+)、CD4^(+)/CD8^(+)高于对照组,CD8^(+)低于对照组(P<0.05)。血清血管内皮生长因子、血小板衍生生长因子、转化生长因子-β1、碱性成纤维细胞生长因子低于对照组(P<0.05)。2组消化道反应、肝功能损伤、肾功能损伤、神经毒性、血小板减少、白细胞减少比较,差异无统计学意义(P>0.05)。结论贝伐珠单抗联合奥希替尼治疗能够提高EGFR-T790M突变晚期NSCLC患者治疗效果,可能与改善细胞免疫功能、抑制相关血管生长因子水平等因素有关。

Cellular Automaton法模拟金属凝固显微组织研究进展

介绍了金属凝固过程中显微组织模拟的数学模型和计算模型以及元胞自动机(Cellular automation)法的原理及发展历程。概述了晶粒形核和生长的几个物理模型,并对元胞自动机在凝固过程中微观组织形成过程的计算机模拟的应用作了较详细的介绍。元胞自动机考虑了形核和生长动力学问题,通过宏微观耦合模型可计算固相分数和潜热释放的变化。介绍了两种元胞自动机和有限元方法的耦合方式,并对元胞自动机法的未来发展方向进行了展望。

Cellular Automaton法模拟铝合金微观组织的形成

采用Cellular Automaton微观模型,在给定冷却曲线的条件下,对铝合金板材凝固过程组织的形成进行了二维数值模拟。采用连续形核的方法处理液态金属的异质形核现象。用CA算法处理晶粒生长过程,考虑了枝晶尖端生长动力学和优先生长方向<100>晶向。通过模拟动态再现了凝固过程中晶粒的形核与生长。结果表明,在形核分布参数不变的情况下,随着冷却速度的增加,所得晶粒尺寸增大。

EFFECTS OF Fe AND Mn ON THE GROWTH OF A RED TIDE DINOFLAGELLATE SCRIPPSIELLA TROCHOIDEA (STEIN) LOEBLCH Ⅲ

Batch culture experiments were conducted with a red tide dinoflagellate Scrippsiella trochoidea(Stein) Loeblch Ⅲ colleted from Jiaozhou Bay, Shandong, China. Growth rates and Cellular Chl-a were meas ured in media with iron and manganese ion concentrations controlled at different levels using EdTA-trace metal buffer systems. Cell density increased 3.2 times to 6.5 times over the range of lowest (0 mol/L) to highest(10-5 mol/L) iron and manganese ion concentrations. The range of Cell density response was much lower than the range of total available iron and manganese, which was >100-fold that of Fe. This nonlinear relationship indicates that the cells adapt to make more efficient use of iron and manganese un der limiting conditions. The cellular Chl-a content maximized after 3 days incubation and then decreased gradually under either iron or manganese limitation conditions. It indicated that the algae gained higher photosynthesis ability when transferred to a new environment. Growth responses to iron and manganese limitation can be both modeled according to the equation of Monod. The half-saturation constant for growth, k, is 4.6×10-8 mol/L for Fe and 5.1×10-8 mol/L for Mn. Our results showed that the iron availability in Jiaozhou Bay does not limit the growth of S. trochoidea.

EFFECT OF NITROGEN AND PHOSPHORUS ON THE GROWTH OF A RED TIDE DINOFLAGELLATE SCRIPPSIELLA TROCHOIDEA (STEIN) LOEBLICH III

Scrippsiella trochoidea (Stein) Loeblich III was grown in a nitrogen or phosphorus limited batch culture system in laboratory. Growth rates and cellular Chl a were measured as functions of nitrate and phosphate concentrations. Growth rates were hyperbolic with both nitrate and phosphate concentration and fit the Monod equation. The minimum cell quota of nitrogen and phosphorus and then the optimum N:P ratio of S. trochoidea were estimated in this study. Measurement of phosphate concentration in Jiaozhou Bay suggest that phosphorus is the limiting factor of S. trochoidea growth.

金属凝固模拟的Cellular Automaton原理及应用

首先介绍了CellularAutomaton的原理及发展历程,然后针对共生生长、枝晶生长及溶质脱熔等情况,详细叙述了在凝固过程计算机模拟中所采用的CellularAutomaton的具体算法,并对其进行了评价,最后展望了未来CellularAutomaton的发展方向。

Role of the nerve growth factor precursor-neurotrophin receptor p75 and sortilin pathway on apoptosis in the brain of patients with intracerebral hemorrhage

This study demonstrated that brain areas surrounding the site of hematoma following intracerebral hemorrhage are characterized by significantly increased apoptosis and expression of neurotrophin receptor p75 and sortilin. However, as detected by terminal deoxynucleotidyl transferase dUTP nick end labeling and immunohistochemical staining, there was no significant change in nerve growth factor precursor expression levels. The appearance of neurotrophin receptor p75 expressing cells was positively correlated with cells that were detected by terminal deoxynucleotidyl transferase dUTP nick end labeling. These findings confirm that the nerve growth factor precursor-neurotrophin receptor p75-sortilin heterotrimeric complex-mediated apoptosis pathway may play an important role in cellular apoptosis following intracerebral hemorrhage.

Microstructure variation and growth mechanism of hypoeutectic Al-Si alloy solidifi ed under high pressure

The microstructure of hypoeutectic Al-9.21wt.%Si alloy solidified under 5.5 GPa was studied.The results show that the solidifi cation microstructure is refi ned.The primary α phase is the extended solid solution.The solid solubility of Si in α phase is up to 8.26wt.%.The growth mode of the α phase is cellular,and this cellular growth mechanism is interpreted in terms of the decrease of the diffusivity and the extended solid solution under high pressure.By calculation,it can be known that the the diffusivity of solute in the liquid under normal pressure is as high as two hundred times that under high pressure.The microhardness of the hypoeutectic Al-Si alloy solidif ied under high pressure is higher than that of solidifi ed under normal pressure.After annealing,Si precipitates from the solid solution,the microhardness of the alloy decrease,but,still higher than that of solidif ied under normal pressure.