铬铁矿酸溶

研究了铬铁矿同硫酸于温度140—210℃进行反应生成硫酸铬的反应动力学，反应的控制步骤为界面化学反应。研究了温度、硫酸浓度及加入高氯酸对反应速度的影响。增加硫酸浓度有利于形成酸不溶的硫酸盐。82％的硫酸于140—210℃间的反应活化能为77千焦耳／摩尔。铬的溶解可用4变量应答曲面模型表述。     

酸温对酸泵正常运转及寿命的影响

硫酸对设备的腐蚀能力与硫酸的温度、浓度有很大的关系。我国中小型的硫酸生产企业,干吸工序使用的酸泵大多是国内生产的铸铁泵或不锈钢泵,这些材料的耐腐蚀能力在很大程度上取决于酸温的高低,即酸泵     

400 kt/a硫酸亚铁和硫磺、硫铁矿混合制酸工程设计

针对硫酸法钛白粉生产中排出的w（H2SO4）20％硫酸和硫酸亚铁,提出一种以焙烧硫酸亚铁、硫磺和硫铁矿生产硫酸的新工艺.重点介绍了焙烧硫酸亚铁制酸的工艺特点、工程难点及主要设备.焙烧硫酸亚铁制酸装置的成功运行从根本上解决了困扰硫酸法钛白粉生产工艺的废渣及副产物问题,使硫酸法钛白粉生产装置大型化得以实现.     

低温稀酸生产硫酸氢钾新工艺

用高温法生产磷酸铵钾的中间体硫酸氢钾,需消耗大量的电力,同时还存在操作困难和水平衡问题。本文提出了低温稀酸法生产硫酸氢钾新工艺,论述了反应完全程度与工艺参数之间的关系,以及新工艺的特点。     

天然石膏制酸联产水泥生产小结

用天然石膏(CaSO_4·2H_2O)生产硫酸,一向是国内硫酸工作者所关心的问题,1990年南京化学工业(集团)公司设计院、山东省建筑材料工业设计院,为我厂设计了一套20kt/a硫酸联产30kt/a水泥的生产装置,通过两年来的生产实践、改造摸索,现已基本掌握了生产规律。主要产品水泥销往山东、江苏、安徽、上海等地,受到用户的好评,硫酸除供本厂生产磷肥外,因不含砷、氟等有害成份,为食品工业所青睐。     

简述云南硫磺制酸的生产特点及管理

简述了硫磺制取硫酸的工艺特点，对硫磺法和硫铁矿法两工艺作了成本比较，认为硫磺法制取硫酸是云南化学工业发展的需要。     

硫化氢制酸的生产技术进展

根据近年的文献报道，评述了硫化氢制酸的生产技术近况。内容包括硫化氢制成硫磺然后再生产硫酸，以及以硫化氢为原料直接制得硫酸。主要从工艺过程、二氧化硫回收率及产品硫酸的浓度等方面加以归纳和概述。通过比较分析得出，湿气制酸（WAX）工艺无论从工艺生产流程，还是二氧化硫转化率、能耗、操作费用和余热回收率等方面都有其独到之处，值得借鉴和引进推广。     

硫铁矿制酸的发展前景分析

分析我国硫酸生产原料结构变化的原因。鉴于硫酸需求的增长及国际硫磺市场供需关系,我国的硫酸生产仍将以硫铁矿为主要原料,并会有较大的发展。采用先进技术、减少“三废”污染、提高废热利用率等措施及提高装置规模效应,是提高硫铁矿制酸竞争力的有效途径。     

硫酸法钛白生产中酸用量探讨

阐述了硫酸法钛白生产中，酸用量对钛白粉的产量、质量和回收率的影响。讨论了总酸用量和总耗酸量的关系，确定了最佳酸用量。举例说明节约用酸的诸种方法。     

石膏制酸装置处理烷基化废硫酸技术介绍

介绍了山东鲁北企业集团总公司利用石膏制酸装置处理烷基化废硫酸生产硫酸的运行实践。利用石膏制硫酸与水泥装置煅烧废硫酸,在石膏煅烧窑中加入废硫酸,废硫酸中的有机物充分燃烧,将硫酸分解后的SO₂再制成合格硫酸,无二次污染。通过小试和大型化运行,证明技术先进可靠,经济效益高,有很好推广价值。     

低分子肝素及其制备

扼要介绍和评述低分子肝素的化学结构、性质、作用机制及其制备方法。     

Basic Amino Acid Residues of Human Eosinophil Derived Neurotoxin Essential for Glycosaminoglycan Binding

Human eosinophil derived neurotoxin (EDN), a granule protein secreted by activated eosinophils, is a biomarker for asthma in children. EDN belongs to the human RNase A superfamily possessing both ribonucleolytic and antiviral activities. EDN interacts with heparin oligosaccharides and heparin sulfate proteoglycans on bronchial epithelial Beas-2B cells. In this study, we demonstrate that the binding of EDN to cells requires cell surface glycosaminoglycans (GAGs), and the binding strength between EDN and GAGs depends on the sulfation levels of GAGs. Furthermore, in silico computer modeling and in vitro binding assays suggest critical roles for the following basic amino acids located within heparin binding regions (HBRs) of EDN ³⁴QRRCKN³⁹ (HBR1), ⁶⁵NKTRKN⁷⁰ (HBR2), and ¹¹³NRDQRRD¹¹⁹ (HBR3) and in particular Arg³⁵, Arg³⁶, and Arg³⁸ within HBR1, and Arg¹¹⁴ and Arg¹¹⁷ within HBR3. Our data suggest that sulfated GAGs play a major role in EDN binding, which in turn may be related to the cellular effects of EDN.     

寡糖的生物活性

寡糖是生命运动中的活性物质。随着研究的深入,它的多种生物活性逐渐为人们所知。近年来我国对寡糖的研究进展很快,本文综述了近年来寡糖生物活性以及应用方面的新进展,包括寡糖的胃肠道活性、增强造血功能、促有丝分裂、抗抑郁、免疫增强、抗病毒、抗菌、抗炎和抗凝血等。     

Polycarbonate urethane films modified by heparin to enhance hemocompatibility and endothelialization

Polyurethane with pendant carboxyl groups was synthesized by a two‐step reaction using methylene diphenyl diisocyanate as hard segments, polycarbonate diols as soft segments and 2,2‐bis(hydroxymethyl) propionic acid as chain extenders. The surfaces of the casting polymer films were further covalently conjugated with heparin as confirmed by Fourier transform infrared spectroscopy. The associated surface‐exposed heparin content was measured to be 1.92 µg cm^?2 and was shown to be active. Meanwhile, surface hydrophobicity decreased after heparin modification. Heparin immobilization greatly improved the hemocompatibility of polyurethane films both in vitro and in vivo. The in vitro cell responses revealed that the expression of proinflammatory markers CD106 and CD62E of human vein endothelial cells was significantly suppressed on the surfaces of the heparinized polyurethane films, while the affinity and proliferation of the cells were improved. The in vivo performance of this material before and after heparin modification was evaluated as a stent coating material in a porcine coronary artery injury model. Histological analysis indicated that heparinized polyurethane induced mild foreign body reactions and inflammation, which were much lower than those induced by unmodified polyurethane. Heparin immobilization also accelerated the endothelialization process on the surface of the polymer‐coated stents when implanted in porcine coronary arteries. More detailed long‐term studies are needed to confirm the biostability of the heparin and the endothelialized surfaces. Copyright © 2012 Society of Chemical Industry     

提高和稳定肝素钠产率的措施研究

研究了提高肝素钠产率的主要工艺条件 ,肝素钠生产中 4种提高收率的方法结果表明 :(1)酶解提取比盐解增加收率 12 .1% ,酶、盐解二次提取提高 11.1%～ 19.2 % ;(2 )二次吸附提高收率 15.1% ;(3)二、三次洗脱分别增加 2 0 .7%和 4 .4 % ;(4 )粗产品精制处理。加入Na2 SO3和沉淀剂YNB 99- 1收率可达 98.1%。 1种稳定产率的措施是逐月增加树脂用量和添加乙醇再生处理树脂。     

肝素中微量硫酸皮肤素的测定方法简介

糖类是最重要的生物信息分子,肝素和硫酸皮肤素同样为具有抗血栓、抗炎等药理作用的糖胺聚糖类药物。本文主要介绍肝素、硫酸皮肤素的检测方法,目的是提供肝素中的微量的硫酸皮肤素定量检测的理论基础,从而能严格有效的控制肝素的质量,避免肝素在临床用药时计量不准、重复用药等问题而造成的一定用药风险。     

Heparin inhibits membrane interactions and lipid-induced fibrillation of a prion amyloidogenic determinant

Glycosaminoglycans (GAGs), particularly heparin, are known to reduce the toxicities of various amyloidogenic proteins. The molecular factors underlying the antitoxic effects of GAGs, however, are still not fully understood. Because interactions of amyloidogenic proteins and their aggregates with membranes are believed to play major roles in affecting amyloid pathogenesis, our objective in this study was to elucidate the effect of heparin on membrane interactions of the 21-residue amyloidogenic determinant of the prion protein [PrP(106-126)]. Indeed, the experimental results indicate that heparin significantly interferes in membrane interactions of the prion peptide. Specifically, we show that there is direct competition for binding of PrP(106-126) between heparin on the one hand and negatively charged phospholipids on the other hand. The data reveal that heparin, even in very low molar concentrations, exhibited high affinity towards PrP(106-126) and consequently suppressed interactions of the peptide with lipid vesicles. Interestingly, whereas heparin significantly inhibited lipid-induced PrP(106-126) fibrillation, it still promoted fibril formation in aqueous solutions independently of the lipid vesicles present. Our results strongly suggest that the primary effects of GAGs in attenuating amyloid toxicities are due to blocking of membrane interactions of the amyloidogenic proteins rather than modulation of their fibrillation properties.     

派罗宁B褪色光度法测微量肝素

在pH 4.10的Britton-Robinson缓冲溶液中,肝素与派罗宁B形成离子缔合物,染料发生明显的褪色,体系吸光度的降低与肝素钠浓度成正比,肝素浓度在0～50 μg·(25 mL)-1范围内符合比耳定律.研究了表面活性剂和共存物质的影响,表明方法选择性好.用于肝素钠注射液效价的测定,结果令人满意.     

肝素和硫酸乙酰肝素抑制草酸钙结石形成的化学基础

从肝素(HP)和硫酸乙酰肝素(HS)的结构和性质出发,综述了HP和HS对草酸钙(CaOxa)结晶和CaOxa结石形成的影响,并从HP相对分子质量、电荷密度和体系离子强度讨论了影响HP抑制活性的因素。HP不但可以与Ca2 离子结合,降低CaOxa溶液的过饱和度,抑制CaOxa晶体的成核、生长和聚集,而且可以保护尿路粘膜,防止晶体粘附。HS对CaOxa结石形成的作用存在抑制和促进两种不同的观点。     

溴代十六烷吡啶共振瑞利散射法测定肝素

基于肝素对溴代十六烷吡啶共振瑞利散射的增强作用,建立了一种测定肝素的新方法.在pH值为5.02～8.3的B-R缓冲溶液中,溴代十六烷吡啶与肝素反应形成缔合物,使溶液共振瑞利散射(RRs)增强,以475 nm处的灵敏度最高,它对肝素的检出限(3σ)为0.052 mg/L.研究了适宜的反应条件和影响因素,表明该方法灵敏、稳...