Effect of particle size on flame retardancy and mechanical properties of hydroxyethyl diphosphate modified aluminum hydroxide intrinsic polyethylene terephthalate

Organic–inorganic hybrid flame retardant was obtained by modifying aluminum hydroxide with different particle size with 1-hydroxyethylidene-1,1-diphosphonic acid. The structure of the organic–inorganic hybrid flame retardant is characterized by Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy, while ¹H-NMR spectroscopy only characterizes specific samples. The thermal stability and flame retardancy of the samples were analyzed by thermogravimetric analysis, limiting oxygen index (LOI), vertical combustion of UL-94 and cone calorimeter. The results show that the modified 10 μm aluminum hydroxide has a better effect than the 25 μm aluminum hydroxide and 100 nm aluminum hydroxide. Compared with pure polyethylene terephthalate (PET), the LOI value of the best sample is increased by 24.4%, and UL-94 V reaches V-0 level. Heat release rate, total heat release rate, and carbon monoxide production rate decreased by 45.8%, 33.2%, and 41.5%, respectively, compared to pure PET. The results showed that the aluminum hydroxide with a particle size of 10 μm exhibited the best flame retardant effect, which could be attributed to the decomposition of organic phosphoric acid and the dehydration of aluminum hydroxide, yielding a higher amount of residual carbon.     

HPLC法分析40%氟噻草胺·吡氟酰草胺·异丙隆悬浮剂含量

[目的]采用HPLC建立检测40%氟噻草胺·吡氟酰草胺·异丙隆悬浮剂含量的方法。[方法]采用高效液相色谱法,以0.1%磷酸水溶液-乙腈为流动相梯度洗脱,使用Extend C18柱和DAD检测器,对试样中的氟噻草胺、吡氟酰草胺和异丙隆进行测定,外标法定量。[结果]该分析方法氟噻草胺、吡氟酰草胺和异丙隆线性相关系数分别为0.9999、0.9999和0.9998,变异系数分别为0.73%、0.84%和0.57%,平均回收率分别为101.09%、100.91%和101.12%。[结论]该方法的操作简单,精密度、准确度和灵敏度均满足要求,可用于40%氟噻草胺·吡氟酰草胺·异丙隆悬浮剂含量检测。     

新一代信息技术助推油库企业数字化转型升级

随着时代发展和科技进步,以5G通信、大数据、云计算、人工智能、区块链等为代表的新一代信息技术为传统企业数字化转型升级带来机遇.在分析国内外油库领先建设实践以及业务现状的基础上,基于数字时代背景下企业信息化建设需求,以实现本质安全环保为方向,以生产管控、安全管控、环保管控为主线,阐述如何融合新一代信息技术建设智能油库的整体解决方案,助推油库生产管理、安全环保、设备管理业务数字化转型升级.     

Molecular Characteristics of Amyloid Precursor Protein (APP) and Its Effects in Cancer

Amyloid precursor protein (APP) is a type 1 transmembrane glycoprotein, and its homologs amyloid precursor-like protein 1 (APLP1) and amyloid precursor-like protein 2 (APLP2) are highly conserved in mammals. APP and APLP are known to be intimately involved in the pathogenesis and progression of Alzheimer’s disease and to play important roles in neuronal homeostasis and development and neural transmission. APP and APLP are also expressed in non-neuronal tissues and are overexpressed in cancer cells. Furthermore, research indicates they are involved in several cancers. In this review, we examine the biological characteristics of APP-related family members and their roles in cancer.     

Ubiquitin-Specific Protease 29 Regulates Cdc25A-Mediated Tumorigenesis

Cell division cycle 25A (Cdc25A) is a dual-specificity phosphatase that is overexpressed in several cancer cells and promotes tumorigenesis. In normal cells, Cdc25A expression is regulated tightly, but the changes in expression patterns in cancer cells that lead to tumorigenesis are unknown. In this study, we showed that ubiquitin-specific protease 29 (USP29) stabilized Cdc25A protein expression in cancer cell lines by protecting it from ubiquitin-mediated proteasomal degradation. The presence of USP29 effectively blocked polyubiquitination of Cdc25A and extended its half-life. CRISPR-Cas9-mediated knockdown of USP29 in HeLa cells resulted in cell cycle arrest at the G0/G1 phase. We also showed that USP29 knockdown hampered Cdc25A-mediated cell proliferation, migration, and invasion of cancer cells in vitro. Moreover, NSG nude mice transplanted with USP29-depleted cells significantly reduced the size of the tumors, whereas the reconstitution of Cdc25A in USP29-depleted cells significantly increased the tumor size. Altogether, our results implied that USP29 promoted cell cycle progression and oncogenic transformation by regulating protein turnover of Cdc25A.     

三维光学扫描技术在3D打印中的应用

采用先进的三维光学扫描技术,借助计算机软件对SLS打印的缸盖上水夹层砂芯进行三维数字化全尺寸扫描,检测分析了SLS打印砂芯尺寸精度及尺寸变化规律。检测结果显示:上水夹层砂芯不满足打印设备精度要求,需要改进打印工艺。根据三维光学扫描检测分析结果明确了3D打印工艺调整方向,改进了工艺打印的缸盖上水夹层砂芯,经过三维光学扫描检测,砂芯尺寸精度得到了有效地提高。通过对三维光学扫描技术在3D打印中的应用研究,对SLS打印砂芯精度检测提供了一种更为准确直观的测量方法,三维光学扫描检测结果作为SLS打印工艺参数调整依据,为SLS打印出合格的砂芯奠定基础。     

Mg-6Al-1Nd-1.5Gd合金的高温蠕变机制

采用高温蠕变装置,研究了Mg-6Al-1Nd-1.5Gd合金在150、175、200℃以及50、70、90 MPa条件下的高温压缩蠕变行为,分析合金在高温蠕变过程中的蠕变机制。结果表明,Mg-6Al-1Nd-1.5Gd合金的平均应力指数及蠕变激活能分别为4.64和73.87kJ/mol,其主要蠕变机制是由位错攀移和晶界扩散共同作用,合金的蠕变本构方程为:ε=1.877×10-8σ4.641exp[-73 865/(RT)];合金在高温蠕变过程中,微观组织中的位错密度逐渐增大,出现位错缠结及位错堆积,合金蠕变后的晶粒变得粗大,金属间化合物Al3Nd和Al3Gd在晶界上出现偏聚。     

JNK信号通路与细胞凋亡关系的研究进展

c-Jun氨基末端激酶(c-Jun N-terminal kinase,JNK)信号通路是近20年来发现的与细胞分化、细胞凋亡、应激反应以及多种人类疾病的发生和发展关系非常密切的通路之一,其生物化学功能和对细胞生理、病理情况下的调节作用一直被国内外学者所关注。近年来,研究发现JNK信号通路在调控细胞凋亡中发挥重要作用,通过调节JNK信号通路有望成为治疗细胞凋亡引起的疾病的重要靶点。本文就其生物学功能及其与细胞凋亡关系作一阐述。     

急性冠脉综合征患者血清高敏C反应蛋白和组织蛋白酶S水平变化与临床意义

目的: 探讨血清高敏C反应蛋白(hs-CRP)、组织蛋白酶S(CatS)与急性冠脉综合征的相关关系。方法: 选择53例急性冠脉综合征患者(ACS组),对照组36例,检测两组血清CatS、hs-CRP水平并进行比较。同时检测ACS组治疗后血清hs-CRP、CatS水平的变化。结果: ACS组在性别、年龄、吸烟、糖尿病、脑梗死、高血压患病率方面与对照组相比,差异无统计学意义(P>0.05);ACS组治疗前血清CatS水平为(0.51±0.03) nmol/L,hs-CRP为(10.21±5.03) mg/L,分别高于对照组的(0.43±0.04) nmol/L 和(3.64±1.87) mg/L,差异具有统计学意义(P<0.05); ACS组治疗后血清CatS、hs-CRP水平分别为(0.45±0.06) nmol/L 和(6.05±3.25) mg/L,较治疗前的(0.51±0.03) nmol/L 和(10.21±5.03) mg/L 明显降低,差异有统计学意义(P<0.05)。结论: ACS患者血清CatS及hs-CRP的水平的变化提示 CatS及hs-CRP可能在ACS发生发展过程中具有重要作用,推测 CatS可能作为ACS的一种新的生物标志物。