恩度对横纹肌肉瘤PLA-802细胞生长的抑制作用及其机制

目的探讨人血管内皮抑制素恩度(Endostar)对横纹肌肉瘤PLA-802细胞生长的抑制作用及其机制。方法将常规培养的横纹肌肉瘤细胞PLA-802分为对照组和恩度处理组(不同浓度处理不同时间),采用MTT法检测恩度对细胞生长的影响;流式细胞术检测细胞周期的变化;RT-PCR和Western blot法检测恩度对细胞内血管内皮生长因子(Vascular endothelial growth factor,VEGF)mRNA和蛋白表达的影响;ELISA检测细胞培养液上清中VEGF的生成水平。结果恩度可抑制PLA-802细胞增殖及VEGF的表达和生成,且上述作用具有显著的浓度-时间依赖性。结论恩度能够抑制PLA-802细胞的生长,其机制可能与阻断VEGF的表达相关。     

Double yielding behavior of in situ microfibrillar polyolefin elastomer/poly(lactic acid) composites: Effect of microfibrillar morphology

In situ microfibrillar composites (MFCs), with polyolefin elastomer as matrix and poly(lactic acid) (PLA) as dispersed phase, were successfully prepared using multistage stretching extrusion system. Interestingly, a peculiar phenomenon of double yielding was observed on the stress-strain curves of MFCs under tensile loading for the first time. The MFCs with 20 wt% PLA microfibrils exhibited two distinct yield points, and a pronounced hump appeared on the stress-strain curve of PLA-20. Two-dimensional small-angle X-ray scattering analyses showed that the equatorial streak scattering became stronger with increase in PLA microfibrillar content; the meridional scattering trace became stronger with increase in tensile strain for PLA-20. The rheological analysis showed that the G′ of PLA-20 had a plateau in the low frequency region and did not depend on frequency changes.     

Flame retardant and antibacterial properties of PLA/PHMG-P/APP composites

Poly(lactic acid) (PLA) has evolved into a commodity polymer with numerous applications. However, its high flammability limits its viability as a perfect alternative to petrochemical engineering plastics. In this study, PLA was modified using polyhexamethyleneguanidine phosphate (PHMG-P) and ammonium polyphosphate (APP). The flame retardant performance of PLA/PHMG-P/APP was investigated based on the limiting oxygen index (LOI), vertical burning test (UL-94), thermogravimetric analysis (TGA), cone calorimetry (CC), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and Raman Spectrometry. Qualitative and quantitative methods were used to determine the antibacterial properties of PLA composites. The LOI of PLA-10% (P:A = 1:4) was 31.7% and was rated V-0 in the UL-94 V-0 test. The antibacterial properties of the composites reflected the antibacterial effects of PLA-10% (P: A = 1:4) against Escherichia coli and Staphylococcus aureus, with the antibacterial rates reaching 93.41% and 93.26%, respectively. PHMG-P and APP had a synergistic flame-retardant effect and improved the flame retardancy of PLA while exhibiting excellent antibacterial properties.     

骨骼肌源性抑瘤物对恶性肿瘤抑制作用的研究

目的研究骨骼肌微环境因素对恶性肿瘤细胞增殖的影响,评价其在骨骼肌转移瘤罕见性中的意义。方法原代培养新生Wistar大鼠骨骼肌细胞,用MTT法分析、比较其条件性上清液(MMCM)对恶性肿瘤细胞(小鼠骨髓瘤细胞株SP2/0、鼻咽癌细胞株CNE、肺巨细胞癌细胞株PLA801C、人食管鳞癌细胞株Eca109、宫颈癌细胞株Hela)及正常非肿瘤细胞(金黄地鼠肾细胞株BHK-21)的体外抑瘤作用。结果MMCM分别与SP2/0、CNE、PLA801C、Eca109、Hela及BHK-21细胞共同培养后,对5株恶性肿瘤细胞的增殖均有明显抑制作用,而正常非肿瘤细胞株则未受影响。结论新生大鼠骨骼肌细胞可产生选择性抑制恶性肿瘤细胞增殖的抑瘤物质,这种抑瘤物质可能是临床上骨骼肌内罕见转移瘤现象的生物学基础。     

小剂量长春新碱和恩度联合用药对横纹肌肉瘤皮下移植瘤的抑制作用

目的研究小剂量长春新碱(Vincristine,VCR)和恩度(Endostar,Endo)联合用药对横纹肌肉瘤(Rhabdomyosarcoma,RMS)BALB/c裸鼠皮下移植瘤的生长抑制作用,并探讨其机制。方法经BALB/c裸鼠右侧腋部皮下注射RMS细胞PLA-802悬液,建立RMS的皮下移植瘤动物模型;接种RMS后第8天,将选模成功的裸鼠随机分为对照组(注射生理盐水)、VCR组、Endo组和联合组,注射部位均为腹腔,注射体积均为0.2 ml/(只.日),每3 d称重1次,并测量肿瘤的长短径,计算肿瘤体积,绘制肿瘤生长曲线,2周后处死裸鼠,称量瘤重,并计算抑瘤率;RT-PCR和Western blot法检测移植瘤细胞中血管内皮生长因子(Vascular endothelial growth factor,VEGF)基因mRNA的转录水平和蛋白的表达水平;免疫组化法检测VEGF和CD31的分布和表达。结果裸鼠接种PLA-802细胞第8天,RMS裸鼠模型复制成功,裸鼠成瘤率为84%(42/50);联合组裸鼠体重和移植瘤的体积、重量均明显小于对照组、VCR组和Endo组(P<0.01);VCR组、Endo组和联合组抑瘤率分别为31.41%、20.75%和48.41%;与对照组相比,VCR组、Endo组和联合组裸鼠移植瘤细胞中VEGF基因mRNA的转录水平和蛋白表达水平均显著下降,且以联合组下降最明显(P<0.05);免疫组化结果显示,联合组VEGF和CD31的表达水平明显低于其他3组。结论小剂量VCR和Endo对RMS的皮下移植瘤的生长具有明显的抑制作用,而联合用药能起到增效作用,其机制可能是通过抑制肿瘤的血管生成而发挥其抑制作用。     

Effect of poly(2-ethyl-2-oxazoline) and UV irradiation on the melt rheology and mechanical properties of poly(lactic acid)

To improve the suitability of poly(lactic acid) (PLA) for implantable devices, it ideally needs greater ductility without losses in strength. Here biodegradable poly(2-ethyl-2-oxazoline) (PEtOx) was selected as an additive to improve hydrophilicity of PLA as well as mechanical properties, while UV irradiation was considered as a bulk modification method to increase the long-term stability. The PLA blend showed improved tensile strength and elongation-at-break with small amounts of PEtOx added (1.5 wt %). Crosslinking by UV irradiation showed significant improvements with a dibutyltin dilaurate catalyst even though it produced a high degree of chain scission during melt processing. After UV irradiation for 150 h, the crosslinked material recovered mechanical properties and melt rheological properties comparable to the initial PLA-1.5%PEtOx blend (without catalyst added). Crosslinking was only possible with the added PEtOx present. A mechanism for the crosslinking reactions examined has been proposed since it has not been previously reported in the literature. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48023.     

水泥水化热测定方法综述

水泥水化热是中、低热水泥和核电工程用水泥的一项关键的技术指标。全球范围内测定水泥水化热的方法有溶解法、直接法/半绝热法、等温传导量热法三种。本文总结了中、美、欧相关方法标准,对其测试原理、仪器设备、试验过程等方面进行了比对,并对其在领域的应用做了简单的概括。     

乙烯酮(双乙烯酮)下游产品废水的治理技术

乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。     

气化给煤系统故障分析

气化给煤装置自投运以来,出现了气化煤仓堵煤、称重给煤机输送皮带因跑偏而损伤以及清扫装置故障频繁等问题,多次造成气化系统减负荷运行。通过对出现的各种问题进行分析,找到了产生这些问题的原因,并有针对性地采用配煤和改进清扫链等措施,使出现的问题得到了极大的改善。     

Stability of granules of solid solutions of poly-pehnyleneterephthalamide

Conclusions Studies of starting solutions of PPTA in sulfuric acid and of granules obtained under pressrue at low temperature, and of granules stored in a hermetic package, have been carried out by the methods of differential thermal analysis, turbidity spectrum and viscometry.On granulation of a solidified PPTA solution, short-term storage of the granules in a hermetic package, or short contanct of the granulated mass with air, no appreciable change in melting point or of the intrinsic viscosity of the system takes place.Long storage of a granulated solution, even in hermetic packages, can lead to a considerable decrease in the melting point of the crystal solvates, caused by an increase in defectiveness of crystal structure under the effect of moisture.Translated from Khimicheskie Volokna, No. 3, pp. 25–26, May–June, 1986.     

Phase behavior of homologous series of monoesters of polyols

Phase behavior of anhydrous monopalmitates and stearates and of most laurates, myristates and behenates of ethylene glycol, erythritol, xylitol, sorbitol, and mannitol has been studied. The compounds, substantially free of diesters, are mostly not isomerically pure but are predominantly primary esters. Also studied were the (nonisomeric) palmitate and stearate of pentaerythritol (Pe) and the oleate of erythritol. Mesomorphism, absent in anhydrous monoglycerides unless of short chain length and symmetrical, is a prominent feature of the members of the present group of compounds containing at least three unesterified hydroxyls. In general, crystal melting points rise with length of polyol, and mesomorphic melting points rise faster. Crystal melting points rise with acyl chain length while mesomorphic melting points run through a maximum. Heats of fusion are of the order 40 cal/g for crystal melting and 0.5 cal/g for melting of mesomorphic states. In the range explored, mesomorphic values fall with both polyol length and acyl length. At higher acyl chain length, notably with behenates, there are new features of mesomorphic behavior. Crystalline phase, from solvent, melts to a neat or lamellar phase, which in turn melts to liquid with subsequent appearance of higher melting middle or cylindrical phase. Polymorphism is general among the crystal states and tends to be complex. In a brief study of solvent crystallized 50–50 binary mixes of xylitol stearate with other xylitol esters and other stearates, considerable evidence of solid solution in Form I crystals (of xylitol stearate type) was observed with very modest eutectic lowering of crystal melting point. Mesomorphic points were almost linearly intermediate between those of components. Of particular interest were mixtures of xylitol stearate and 1-monostearin (50–50 and 25–75), for which mesomorphic melting points were realized, and for which an extrapolation to 100% monostearin leads to a hypothetical mesomorphic melting point far below any monoglyceride crystalline melting point. A brief examination of an aqueous xylitol palmitate system explored to a maximum temperature of 165 C shows extensive occurrence of aqueous mesomorphic state somewhat after the manner of monoglyceride systems. Mesomorphic melting level rises rapidly from the value for anhydrous ester.     

我国聚丙烯工业国际竞争力分析

应用管理学和市场营销学的基本原理和方法,深入分析我国聚丙烯工业的内部和外部环境、市场状况以及加入WTO后所面临的机遇与挑战.在此基础上,应用SWTO(态势分析法),确认出主要的优势和劣势、机会和威胁,对我国聚丙烯工业的国际竞争力进行结构化的综合分析.     

化学化工数据局外点检测方法研究进展

局外点检测对于注重试验和数据采集的化学化工领域,其重要性不可忽视。结合化学化工的数据特点,对局外点检测方法的理论基础、应用需求、研究思路、技术关键和发展进程进行了综合分析。分别针对线性和非线性参变对象,概要介绍了当前适用的检测方法,包括各类判别标准、直接和间接方式、单个和多个局外点检测、经典和现代方法以及它们的优缺点和最新进展。最后展望了局外点检测方法的前景和发展方向。     

Analysis of products of high-temperature pyrolysis of various hydrocarbons

Ethane, ethylene, acetylene, propane and neopentane have been pyrolyzed at 1173 K, and methane at 1372 K in a flow system, and the volatile pyrolysis products analyzed. Eleven aromatic hydrocarbons, containing 14 or fewer carbon atoms, accounted for 98 + % of the liquid products recovered in each case. Benzene was the main product, followed by naphthalene. No compounds with branched chains or multiple substituents were present, and compounds containing even numbers of carbons comprised 93–99% of each mixture. Acetylene was a major component of the gaseous effluent from each of the initial hydrocarbons. The effect of temperature on the composition of the gaseous effluent during pyrolysis of methane, ethane and ethylene was determined. Carbon film deposition from methane commenced at about 1273 K; from ethane at 1015 K and from ethylene at 1100 K, in each instance coinciding with the appearance of acetylene in the effluent. As the temperature was raised, at first the increase in the rate of carbon deposition closely followed the increase in the concentration of acetylene in the effluent. It is proposed that acetylene may be a common factor in the pyrolysis of aliphatic hydrocarbons, perhaps acting as the precursor of both surface carbon and aromatic hydrocarbons by a process of head-to-tail linkage of two-carbon units at active surface sites to form chains that then undergo dehydrogenation to carbon or cyclization and desorption as aromatic species.     

辅助药型罩材料对超聚能射流性能影响的数值模拟

为了研究超聚能射流形成过程中辅助药型罩材料对射流性能的影响,利用AUTODYN-2D软件,采用高精度多物质求解器Euler-2D Multi-material对辅助药型罩材料分别为Wu、Cu、Fe,锥形药型罩材料为Al的截顶辅助药型罩超聚能装药进行模拟。结果表明,与传统聚能装药相比,超聚能装药结构形成的射流性能更优。辅助药型罩材料密度越大,超聚能射流形态和连续性越好;超聚能射流具有更高的头部速度和能量。用Wu、Cu、Fe作辅助药型罩材料时,超聚能射流的最大速度分别为14 400、13 300和13 100m/s,最大能量分别为10.2×10~7、8.5×10~7、7.5×10~7 J/kg,并且材料密度越大,起爆后相同时刻的射流形态越细越长。     

142例新生儿溶血病血清学检测结果分析

目的对本地区142名新生儿溶血病患者进行血清学检测,评价直接抗人球蛋白试验、游离抗体试验和抗体释放试验在该病诊断中的价值。方法对2005年1月~2007年6月各医院送检的高胆红素血症新生儿血液标本进行"三项试验"。结果142名新生儿溶血病患者中,血型分布规律为:B>A>AB>O,54.22%为B型,43.66%为A型,二者差异有显著意义。直抗试验阳性率为76.76%,释放试验阳性率为100%,游离试验阳性率为50.70%。释放试验阳性的A型患者中,抗-AB检出率为47.17%,B型患者中的检出率为53.03%,二者差异无显著意义。结论释放试验敏感度最高,是判定新生儿溶血病最有力的证据,在本地区,B型新生儿可能更易患新生儿溶血病。     

Effect of degree of deacetylation of chitosan on the kinetics of ultrasonic degradation of chitosan

The objective of the study was to explore the effect of the degree of deacetylation (DD) of the chitosan used on the degradation rate and rate constant during ultrasonic degradation. Chitin was extracted from red shrimp process waste. Four different DD chitosans were prepared from chitin by alkali deacetylation. Those chitosans were degraded by ultrasonic radiation to different molecular weights. Changes of the molecular weight were determined by light scattering, and data of molecular weight changes were used to calculate the degradation rate and rate constant. The results were as follows: The molecular weight of chitosans decreased with an increasing ultrasonication time. The curves of the molecular weight versus the ultrasonication time were broken at 1‐h treatment. The degradation rate and rate constant of sonolysis decreased with an increasing ultrasonication time. This may be because the chances of being attacked by the cavitation energy increased with an increasing molecular weight species and may be because smaller molecular weight species have shorter relaxation times and, thus, can alleviate the sonication stress easier. However, the degradation rate and rate constant of sonolysis increased with an increasing DD of the chitosan used. This may be because the flexibilitier molecules of higher DD chitosans are more susceptible to the shear force of elongation flow generated by the cavitation field or due to the bond energy difference of acetamido and β‐1,4‐glucoside linkage or hydrogen bonds. Breakage of the β‐1,4‐glucoside linkage will result in lower molecular weight and an increasing reaction rate and rate constant. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3526–3531, 2003     

Model of Cellular Instability of Flames of Ternary Mixtures

A simple phenomenological diffusive-thermal model of cellular instability of premixed flames of ternary mixtures is developed and presented. The model shows that preferential diffusion can alter stoichiometry of the mixture, i.e., the ratio of the fuel and oxidizer concentrations, and also its effective dilution by an inert. Key parameters of the model are estimated using numerical modeling of burning velocities. Laminar burning velocities are calculated for hydrogen-oxygen-nitrogen, methane-oxygen-nitrogen, and propane-oxygen-nitrogen mixtures. Conditions for the appearance of cellular instability in ternary mixtures are determined and compared with experiments. In good agreement with experimental observations, the diffusive-thermal instability is predicted in hydrogen flames with equivalence ratios φ ≲ 1.45, in lean methane flames with φ ≲ 1.02, and in rich propane flames with φ ≳ 1.03. The magnitude of the change in the local flame velocity due to preferential diffusion is evaluated. It is demonstrated that nitrogen diffuses faster than oxygen in hydrogen-air and methane-air flames, while oxygen diffuses faster than nitrogen in flames of propane and other heavier hydrocarbons. In mixtures of air with propane or heavier hydrocarbons, the transition between stable and unstable regimes is predicted in mixtures that are leaner than the mixture corresponding to the peak of the burning velocity curve, in agreement with experimental observations. __________ Translated from Fizika Goreniya i Vzryva, Vol. 41, No. 5, pp. 14–22, September–October, 2005.     

浅谈安全中的“以人为本”

在安全生产系统中,人的素质是占主导地位的,人的行为贯穿生产过程的每一个环节。企业安全要以人为核心,树立人本观念。安全管理必须重视人的因素,提高人的素质,从精神上、物质上关心人尊重人,以有效的手段约束和激励人,加大安全投入、落实有效措施,保障个人的利益,使大家找到归属感,保护员工身体健康和生命安全,最终形成安全管理＂命运共同体＂,推动企业发展和提高。     

六甲基二硅烷-甲苯-水混合物的清洁分离工艺设计

在对六甲基二硅烷(HMDO)-甲苯-水三元体系进行了热力学分析的基础上,应用化工流程模拟软件ASPEN PULS对工艺过程进行模拟。提出了共沸蒸馏、萃取的分离方案,筛选了5种共沸剂,结果表明丙酮为最佳共沸剂。丙酮与HMDO-水形成共沸物,分离甲苯;共沸物通过萃取的方式分离HMDO;水与丙酮可以通过普通精馏的方法得以分离,整个过程中的共沸精馏溶剂和萃取剂-水全部循环使用,没有废液的排放,实现了清洁生产。提出的工艺方案可为工业装置设计提供参考。