嗜热芽孢杆菌SL-2产生物乳化剂的研究

生物乳化剂是一种由细菌新陈代谢形成的生物表面活性化合物。在胜利油田油井中分离并检测到了一株能形成某种生物乳化剂的菌株SL-2,经确认是苍白地芽胞杆菌。深入研究发现,该菌株所形成的生物乳化剂的化学构成和理化特性对研究中高油藏生物乳化剂有着重大价值。在试验中通过化学显色、红外光谱和氨基酸自动解析法等方式,确认生物乳化剂的化学构成;通过乳化物在不同条件下产生的乳化指数（EI-24）判断其理化特性。通过结果可确定由菌株SL-2在60℃条件下生长所形成的乳化剂的主要成分是多糖、脂类和蛋白质,其主要活性成分蛋白质对汽油、甲苯、二甲苯和煤气等石油烃都有很好的乳化效应;理化特性分析进一步表明,该乳化剂具有耐高温、耐盐、抗酸的优异性能。     

磷-化学工业中的多面手

磷在化学史上是发现较早的元素之一。许多元素都是从矿石中发现的,唯独磷是最早从有机物质中发现的。磷在生物有机体内含量较高,一个成年人体内大约含1千克左右的磷质,骨头的磷酸钙里有磷,脑磷脂里也含磷。这些化合态的磷在动物尸体腐烂时,被土壤里的细菌分解为磷化氢气体冒出地面,遇到空气自燃,形成所谓的“鬼火”。     

微生物降解木质素的研究进展

木质纤维是地球上最丰富的可再生生物质资源,其三大成分之一的纤维素是生产生物基材料、生物燃料及生物基化学品的重要原料,但是木质素复杂的化学结构阻碍了木质纤维的应用.常规木质素的物理、化学及物理-化学等降解方法常需要高温、高压条件,并且易产生抑制物、造成高能耗和环境污染等问题.微生物介导的生物催化过程通常在温和条件下进行,...     

用EDGE法制备羟基磷灰石/明胶交联纳米复合材料

钙化组织,比如骨头和牙齿,是一种由无机磷灰石纳米晶体嵌入胶原[COL]和非胶原蛋白有机基体以生物和化学结合所构成的复合材料[1,2]。在这些有机基体上的阴离子和阳离子侧链很容易地与磷灰石表面上的钙和磷酸盐相结合。羟基赖氨酸含量较高的骨胶原对羟基磷灰石[Hap]具有优良的化     

含醛基聚合物在生物医药领域中的应用研究进展

含醛基功能高分子具有通用、灵活、使用方便等优点,因其醛基能在温和条件下与氨基形成Schiff碱,便于共价固定生物大分子(如蛋白质)等,而广泛应用于生物和医药领域。综述了含醛基聚合物在药物控制释放、酶和细胞的固定化、临床诊断试剂和组合化学中作为载体材料的应用研究进展。     

超声空化及其在石油工业中的应用

空化是超声技术应用于各个领域发挥其作用的核心效应,声空化机制是声化学的主动力。在超声正负交变声压下,液体介质中的微泡成长、压缩至溃破的过程中,会形成局部的高温高压、强烈的冲击波和高时速射流,使得介质能产生各种物理、化学和生物效应,如乳化、离散、凝聚等,这样的条件为一些化学反应开启了新通道,从而很好的应用于石油领域。     

化学生物絮凝工艺处理城市污水的试验研究

试验采用化学生物絮凝工艺处理上海市低浓度城市污水，分析不同聚合氯化铝铁(PAFC)投加量条件下的污染物去除效果．探讨化学生物絮凝工艺的反应实质。平行对比试验结果显示：化学生物絮凝工艺是一种化学和生物协同作用深度集成的污水强化一级处理工艺，在相同加药量条件下，该工艺对污染物的去除效果显著优于化学强化一级处理工艺；在总水力停留时间2h，污泥回流比33％，聚丙烯酰胺(PAM)投加质量浓度0．5mg／L，化学生物絮凝池各廊道的DO值分别为1．9．3．2mg／L、1．3～2．5mg／L和0．3-1．5mg／L的条件下，液体PAFC投加质量浓度为70mg／L(Al2O3 10．8％．Fe2O31．8％)时，化学生物絮凝工艺的出水CODcrTP、SS和NH3浓度满足城市污水综合排放二级标准。     

仿生合成在有机合成中的研究进展

有机化学领域的仿生合成也就是生物有机合成.其发展依赖于生物化学和生物学的理论、方法、技术和原理,即在分子水平上模拟生物的功能,将生物的功能原理用于化学,借以改善现有的和创造崭新的化学原理和工艺.生物有机合成以其反应条件的温和化、无污染、立体专一性强等突出特点和优势成为绿色化学的重要体现.     

名词浅释

<正> 边缘科学各种科学互相交叉、互相渗透、互相促进而形成的科学。系统科学、环境科学、量子化学、遗传工程等等都是边缘科学,为科学的飞跃发展创造了有利的条件。例如量子化学是位于物理、化学、生物和计算数学四门科学交界处的一门边缘科学。它的研究可以使人们避免盲目地摸索的曲折道路,揭开化学的秘密现象,有预见地设计物质分子,进而     

生物催化技术在化学制药中的应用研究与分析

随着我国经济的不断发展,人们的生活水平不断提高,人们对医疗事业的关注程度也不断增长。在这样的背景之下我国的制药工程事业得到了快速的发展。现阶段为了提高化学制药的效率,生物催化技术被广泛的应用在化学制药工程当中,并且已经初步形成了生物催化化学制药工业化。对生物催化制药的含义进行了分析,并以此为基础介绍了生物催化技术在化学制药中的具体应用。     

Uniaxial Hydroxyapatite Growth on a Self-Assembled Protein Scaffold

Biomineralization is a crucial process whereby organisms produce mineralized tissues such as teeth for mastication, bones for support, and shells for protection. Mineralized tissues are composed of hierarchically organized hydroxyapatite crystals, with a limited capacity to regenerate when demineralized or damaged past a critical size. Thus, the development of protein-based materials that act as artificial scaffolds to guide hydroxyapatite growth is an attractive goal both for the design of ordered nanomaterials and for tissue regeneration. In particular, amelogenin, which is the main protein that scaffolds the hierarchical organization of hydroxyapatite crystals in enamel, amelogenin recombinamers, and amelogenin-derived peptide scaffolds have all been investigated for in vitro mineral growth. Here, we describe uniaxial hydroxyapatite growth on a nanoengineered amelogenin scaffold in combination with amelotin, a mineral promoting protein present during enamel formation. This bio-inspired approach for hydroxyapatite growth may inform the molecular mechanism of hydroxyapatite formation in vitro as well as possible mechanisms at play during mineralized tissue formation.     

The Effects of Immunosuppressive Treatment during Pregnancy on the Levels of Potassium,Iron, Chromium,Zinc, Aluminum,Sodium and Molybdenum in Hard Tissues of Female Rats and Their Offspring

The ideal immunosuppressive regimen should provide for excellent immunosuppression with no side effects. Yet, current immunosuppressive therapy regimens commonly used in clinical applications fail to meet this criterion. One of the complications caused by immunosuppressive drugs is mineralization disorders in hard tissues. In this study, we evaluated the effects of three immunosuppressive therapies used after transplantation on the levels of potassium, iron, chromium, zinc, aluminum, sodium and molybdenum in the bones and teeth of female rats and their offspring. The study was conducted on 32 female Wistar rats, subjected to immunosuppressive regimens (cyclosporine A, mycophenolate mofetil and prednisone; tacrolimus, mycophenolate mofetil and prednisone; and cyclosporine A, everolimus and prednisone). The hard tissues of rats were analyzed using inductively coupled plasma optical emission spectrometry (ICP-OES, ICAP 7400 Duo, Thermo Scientific) equipped with a concentric nebulizer and a cyclonic spray chamber. All the immunosuppressive regimens included in the study affected the concentrations of the studied minerals in hard tissues of female rats and their offspring. The therapy based on cyclosporine A, everolimus and prednisone led to a decline in the levels of iron in bone, zinc in teeth, and molybdenum in the bone and teeth of mothers, while in the offspring, it caused a decline of bone potassium, with a decrease in iron and increase of molybdenum in teeth. Moreover, the regimen caused an increase in aluminum and chromium in the teeth and aluminum in the bones of the offspring, and consequently, it seems to be the therapy with the most negative impact on the mineral metabolism in hard tissues.     

Calcification-Based Cancer Diagnosis and Therapy

In nature, calcium deposition is a common biological process in mammals that shapes mechanical structures and creates the functions of bones and teeth, and causes calculi formation. Spontaneous tumor calcification and regional lymph node calcification in colorectal cancer, lung cancer, and glioblastoma have been proven to be benign prognostic factors in the clinic. In line with this concept, we introduce the idea and lead the compound development of artificially inducing bionic calcification around the surface of cancer cells. This process is shown to have excellent effects in the inhibition of growth and metastases of cervical, breast, and lung tumors, as well as superb performance in early-stage diagnosis. Therefore, we predict that this concept may open the door for cancer targeting calcification therapy and diagnosis and provide an outlook for a new avenue in anticancer drug development.     

Calcium zirconium silicate (baghdadite) ceramic as a biomaterial

Bioceramics have been widely used for many years to restore and replace hard tissues including bones, teeth and mineralized matrices such as calcified cartilages at osteochondral interfaces, mainly because of their physicochemical similarity with these tissues. Calcium silicate based bioceramics have been shown to possess high bioactivity due to having high apatite-forming ability and stimulating cell proliferation, as well as biodegradability at rates appropriate to hard tissue regeneration. The outstanding biological properties of these ceramics have made them the most studied hard tissue engineering biomaterials along with calcium phosphates and bioactive glasses. Baghdadite is a calcium silicate containing zirconium ions which promotes the proliferation and differentiation of human osteoblasts and consequently increases mineral metabolism and ossification. Recently, it has attracted considerable attention in academic community and widely studied in the form of porous scaffolds, coatings, bone cement and void fillers, microspheres and nanoparticles mostly in orthopedic, dental and maxillofacial applications. This review paper is aimed to summarize and discuss the most relevant studies on the mechanical properties, apatite formation ability, dissolution behavior, and in vitro and in vivo biological properties of baghdadite as a biomaterial for hard tissue regeneration applications.     

生物矿化及仿生矿化中的信息传递和转化

牙齿、骨骼、贝壳等生物矿物具有多级有序的结构和优异的力学性能,是生物矿化过程调控下的矿化结晶产物。生物矿化中的矿物与生物有机基质之间的界面分子识别和结晶调控策略为深入理解化学工程中的“信息传递和转化”范式提供了良好的学习素材。以生物矿化典型无机矿物磷酸钙和碳酸钙体系为例,从生物矿物-溶液界面结构、生物分子与矿物晶面的分子识别、矿物结晶调控三个层面综述了生物矿化的化学调控原理,并从信息传递和转化的化学工程范式出发,分析了生物矿化中分子工程和结晶调控策略。绿色高效的生物矿化过程调控策略有望应用于未来化学工程以解决目前面临的需求倍增和资源短缺的全球性问题。     

CaO-P2O5-MgO-SiO2-F系可切削生物微晶玻璃的制备

以CaO-P2O5-SiO2玻璃系统为基础成分，添加适量的F^-,Mg^2 等离子，经过适当的热处理，制备出了含有氟磷灰石的氟金云母相的可切削生物活性微晶玻璃，用差热分析（DTA），扫描电镜（SEM），X射线衍射（XRD）等对该微晶玻璃的显微结构及主晶相的种类进行了研究，并对材料的可切削性及强度进行了测定.实验结果表明，该材料具有较高的抗弯强度和优良的可切削性，其平均抗弯强度为202MPa;该材料在15s内的钻削深度为2．1mm。     

医用双相磷酸钙陶瓷的制备工艺研究

医用双相磷酸钙（BCP）陶瓷是β-磷酸三钙（β-TCP）和羟基磷灰石（HA）的复合体,其成分与骨矿物组成类似,在生理环境下能发生不同程度的降解,被组织吸收。通过化学沉淀法制备纳米羟基磷灰石,然后通过可溶性钙盐和磷酸盐反应工艺制得的β-磷酸三钙,最后将二者进行机械复合而制得双相磷酸钙,将所得样品用X射线衍射仪（XRD）对样品进行了表征。结果显示：所得的双相磷酸钙中掺杂有β-焦磷酸钙,但是它的结晶较好,并且可以改善双相磷酸钙陶瓷的力学性能。     

Bioinspired synthesis of novel teeth‐like hierarchical architecture polyaniline/lead tungstate nanocomposites with photoluminescence property

Large‐scale one‐step synthesis of novel teeth‐like hierarchical architecture polyaniline (PANI)/lead tungstate (PbWO4) nanocomposites has been achieved from aqueous solution by in situ polymerization at room temperature. The reaction conditions, such as pH value and the molar ratio, are found to play a crucial role in controlling the size and morphology of the products. The model of “nucleation‐growth‐assembly” is proposed to explain formation mechanism of the teeth‐like PANI/PbWO₄ nanocomposites. Interestingly, the larger size and higher crystallinity are beneficial to the improvement of photoluminescence (PL) intensity. POLYM. COMPOS., 35:516–522, 2014. © 2013 Society of Plastics Engineers     

Content and absorption of calcium in diets of Northwestern Mexico: a bibliographic retrospective

Calcium is an essential mineral in humans for growth and development of bones and teeth. In adults, bone activity is limited to maintaining bone mass and in order to do this, an adequate intake of calcium is necessary. The objective of this study was to conduct a review of the information available in the literature on the content and availability of calcium in the diet in Northwestern Mexico. The diet studies show that the amount of calcium (1164 mg/d) in the diets in Northwestern Mexico meets the RDA for adults 25 or older and that the principal sources of calcium are corn tortillas, wheat flour tortillas and beans. Bioavailability of calcium in diets containing these foods increases when small amounts of dairy products are added to the diet. This same difference in the availability of calcium was observed in an in vivo study conducted in young women. We can conclude, based on the studies mentioned, that it is necessary to evaluate the effect of calcium in the diets of Northwestern Mexico directly in the general population taking into consideration factors that may play a role in maintaining bone structure such as exercise, age, sex.     

医用双相磷酸钙陶瓷的制备工艺研究

医用双相磷酸钙（BCP）陶瓷是β-磷酸三钙（β-TCP）和羟基磷灰石（HA）的复合体,其成分与骨矿物组成类似。它具有良好的生物相容性,在生物医学领域具有非常广阔的应用前景。且在生理环境下能发生不同程度的降解,被组织吸收。通过化学沉淀法制备纳米羟基磷灰石,然后通过可溶性钙盐和磷酸盐反应工艺制得β-磷酸三钙,最后将二者进行机械复合而制得双相磷酸钙,将所得样品用X射线衍射仪（XRD）进行了表征。结果显示：所得的双相磷酸钙中掺杂有β-焦磷酸钙,但是它的结晶较好,并且可以改善双相磷酸钙陶瓷的力学性能。