FTIR-ATR Spectrometry of BSA Adsorption on Hydroxyapatite

采用傅里叶变换红外衰减全反射(FTIR-ATR)光谱法对牛血清白蛋白(BSA)在羟磷灰石(HA)[Ca_(10)(OH)_2(PO_4)_6]表面不同时间的相互吸附作用进行了表征。在BSA溶液作用下,羟磷灰石表面的Ca~(2+)、PO_4~(3-)和OH~-离子初始的溶解和再沉淀使得BSA与HA相互作用层层叠加,在HA表面形成从表层到次表层分子都包含有吸附的BSA的覆盖层,从而加深两者之间的相互作用。经红外差谱法处理过的相关ATR数据表明,BSA与HA之间的相互作用是快速的,并随时间变化进一步加强;来自HA上PO_4~(3-)的P=O基团对蛋白质肽键的酰胺Ⅱ带(-CNH)、多肽链的甲基(-CH_3)和亚甲基(-CH_2)上氢的吸附作用要比P-O快速而且强烈。Ca~(2+)在该吸附过程中起了极其重要的作用,其快速与蛋白质肽键的羰基氧发生作用,并诱导该蛋白质二级结构由β-折叠向α-螺旋和β-转角构象转变;伴随着这一构象变化,蛋白质多肽链上大多数肽键的-C=O和H-N-活性基团从链间氢键交联中释放出来,带动众多的氢分别参与同HA表面的Ca~(2+)、PO_4~(3-)和OH~-离子的相互吸附作用,并牢牢地结合于HA表面;这对硬组织的再生起着重要作用,促进了HA的生物矿化过程。The microcosmic process of bovine serum albumin(BSA) adsorbing onto hydroxyapatite(HA) for different time intervals was investigated by Fourier transform infrared attenuated total internal reflectance(FTIRATR) spectrometry.The initial dissolution and re-precipitation of PO_4~(3-),Ca~(2+),and OH~- ions from the HA coating led to the occurrence of the coating including adsorbed BSA on the HA from surface-to subsurface-molecular layers and to in-depth interaction between BSA and HA.The subtraction results gained in the adsorption regions of HA and BSA reveal that the binding of P=O,from the phosphate(PO_4~(3-)),to the hydrogen of amide Ⅱ,methyl and methene of the BSA appears to be considerably more rapid and stronger than that of the P—O group.In addition,it is very likely that Ca~(2+) plays an important role in the interaction of BSA with HA.It appears that the binding of Ca~(2+) to the carbonyl-oxygen of the peptide bond in BSA caused a significant,molecular,conformational rearrangement of polypeptide backbones from β-pleated sheet to helical circles of α-helix and β-turn.This change appears to have been followed by much hydrogen of polypeptides being driven to bind PO_4~(3-) and OH~-effectively and much-C=O and H-N- groups of the peptide bond being freed from inter-chain hydrogenbonding to act on Ca~(2+) and combine strongly with the HA surface.This might reasonably be expected to promote hard tissue regeneration.BSA seems to be activated by the inductive effect of Ca~(2+) via the molecular rearrangement of polypeptide backbones from pleated sheet to helical circles and in turn reacts strongly on the HA,resulting in profound effects on the course of biomineralization.国家自然科学基金(51571169)资助项目~

化工基础教学中学生工程观念的培养初探

结合自己在教学中如何培养学生工程观念的若干体会,探讨如何在具体事例中引导学生分析和解决工程问题。以提高学生学习本课程的积极性,最终掌握化工基础的基本内容

Numerical simulation of natural convection in the transient gas-liquid unsteady absorption process

传质过程中液相密度变化导致的自然对流,改变了液相流动状态,对传质有着较大的影响。利用纹影仪光学方法,获得了乙醇吸收CO2过程中自然对流的纹影图像;并通过吸收传质流体CFD模型,应用有限元方法对气液吸收过程中出现的自然对流发生过程进行了数值计算,得到了液相自然对流发生时的非稳态流场分布和浓度分布信息。分析结果表明传质过程中当自然对流发生后,促进了液相表面更新,加强了传质效果,在考察相际传质过程时,应充分考虑自然对流对传质速率的影响。The natural convection occurred in mass transfer process due to change of liquid-phase density gradient usually induces a higher mass transfer rate.By means of the Schlieren technique,Schlieren images of the natural convection were taken in CO_2-ethanol absorption system.Unsteady flow and concentration fields in the liquid phase of a gas-liquid contacting system were simulated to show the natural convection by utilizing the finite-element CFD method.According to the simulated and the experimental results,the influence of the natural convection on mass transfer was analyzed qualitatively.The result shows that the natural convection can facilitate the renewal of the surface and the mass transfer process.So the influence of natural convection on mass transfer should be fully considered in the investigation of interfacial mass transfer.国家自然科学基金资助项目(20606027);; 厦门大学科技创新工程基金资助项目(XDKJCX20041004

多壁碳纳米管活化A549细胞核转录子-κB的机制

探讨多壁碳纳米管对人肺上皮细胞A549核转录因子-κB(NF-κB)活性的影响及其活化机制.不同浓度的多壁碳纳米管作用于A549细胞后,用活性氧(ROS)敏感探针2′,7′-二氯荧光素二乙酸酯结合流式细胞仪检测细胞内氧化应激状态;用凝胶电泳迁移率改变这一分析技术检测A549细胞NF-κB DNA结合活性;用蛋白印迹检测A549细胞NF-κB p65蛋白和IκBα蛋白表达;用免疫荧光结合共聚焦显微镜观察A549细胞NF-κB p65蛋白的核转位情况.结果表明,多壁碳纳米管诱导A549细胞内ROS过量产生和NF-κB DNA结合活性;同时伴有p65蛋白核移位和IκBα蛋白胞浆降解.抗氧化剂N-乙酰半胱氨酸(NAC)可抑制多壁碳纳米管诱导的A549细胞内ROS产生、NF-κB DNA结合活性、p65蛋白核移位以及IκBα蛋白降解.结果表明,多壁碳纳米管可以通过诱导A549细胞氧化应激机制从而活化核转录因子NF-κB活性

Permeation and characterization of TiO_2/PVA hybrid membranes

通过纳米TiO2粒子填充改性制备了新型TiO2/PVA杂化膜。红外光谱表明纳米TiO2表面的羟基与聚乙烯醇(PVA)链上的羟基存在较强的氢键作用。扫描电镜显示当TiO2的质量分数低于1.5%时,在PVA中分散均匀。X射线衍射显示纳米TiO2的加入降低了膜的结晶度。通过对含水质量分数低于20%的水/乙醇体系的脱水研究了该杂化膜的渗透性能,考察了TiO2粒子填充量、料液质量分数和温度与膜分离性能之间的关系。渗透通量J随着TiO2、水质量分数和温度的升高而增加,分离因子随着温度和水质量分数的升高而下降,在TiO2质量分数为1.5%时分离因子达到最佳值。40℃下分离质量分数85%的乙醇水溶液,分离因子可达1 590,渗透通量为0.049kg/(m2.h)。Novel nanometer-sized TiO2 filled polyvinyl alcohol(PVA) membranes were prepared.Fourier transform infrared(FTIR) indicates that there is a strong hydrogen-bond interaction between PVA and TiO2.Scanning electron microscope(SEM) shows that TiO2 particles are well distributed in the membrane matrix when TiO2 mass fraction is less than 1.5%.X-ray diffraction(XRD) reveals that the crystallinity of the hybrid membrane is lower than that of the PVA membrane.The permeation properties of the membrane was studied through the dehydration of water/ethanol system,of which water mass fraction is less than 20%,and the effects of TiO2 mass fraction,feed water mass fraction and temperature on the permeation properties of the membrane were investigated.The results show that the permeation flux J increases with increasing TiO2 mass fraction,feed water mass fraction and temperature.Meanwhile,the separation factor α decreases with increasing the feed water mass fraction and temperature.Separation factor arrives at an optimal value when TiO2 mass fraction is 1.5%.The separation factor and permeation flux reach 1 590 and 0.049 kg/(m2·h) respectively for the separation of mass fraction 85% ethanol/water solution at 40 ℃.国家自然科学基金资助项目(50573063);; 教育部新世纪优秀人才支持计划资助项

Shadowg raph observat ion on interfacial turbulence phenomena in gas-liquid mass transfer

联系人及第一作者: 沙勇( 1971- ) , 男, 博士, 副教授。[中文文摘]引言在相际质量传递过程中,界面处液体物化性质由于物质传递发生改变,如产生密度梯度和界面张力梯度,使界面流体发生流动的现象即为界面湍动。通常由界面处流体密度梯度引发的界面湍动称为Rayleigh-Bénard对流,而由界面表面张力梯度引发的界面湍动,称为Marangoni对流[1]。由于传质过程中发生的界面湍动在临近界面处发生,其浓度场和速度场难以测量,目前多利用纹影法、投影法、干涉法等光学测试手段,对其湍动形态进行观察,为了解界面湍动提供直接视觉证据。利用蒸发、吸收、解吸、萃取等传质手段,不同的研究者对界面湍动进行了直接光学观察,考察了不同传质条件下的界面湍动结构,获取的形态众多,结构复杂[2-7]。对于气-液界面传质导致的界面湍动,其光学观察多集中在研究界面平面内出现的细胞形、六边形、滚筒形等规则或不规则形态,通常为湍动充分发展后的形态,尺度偏大[6-9],而对于实际应用中更重要的界面湍动向主体相渗透的时空观察,十分匮乏,尚需大量设计精巧的实验以揭示其内在的规律。传质过程中产生的界面湍动为强非线性传质流动耦合现象,是非线性理论良好的研究对象[10],并且界面湍动促进了流体表面更新,可对宏观传质设备传质产生显著影响[11],对其的深入研究有着理论和实际上的需要。 本文利用放大界面区域的投影法, 观察有机溶剂水溶液挥发过程中,由界面向液相主体渗透的界面湍动结构, 获取直接视觉资料。 [英文文摘]In gas-liquid mass transfer processes,interfacial turbulence may occur due to the surface tension gradient and the density gradient produced by mass transfer near the interface.The interfacial turbulence can enhance the mass transfer since it intensifies the movement of interfacial fluid.By means of the shadowgraph optical method,the interfacial turbulence patterns vertical to the interface were observed directly in the volatilization process of binary systems.The images of the amplified interfacial turbule showed the variation of concent ration and the fluid movement under the interface. Two patterns of interfacial turbulence were observed in the experiments: plume and vortex.With the plume, the interfacial fluid moved slowly and penet rated the liquid deeply.With the vortex, the inter facial turbulence occur red in the vicinity of the liquid interface and the fluid moves quite fast. A qualitative analysis was carried out based on the mechanism of Rayleigh-Bénard convection induced by density gradient and Marangoni convection induced by surface tension gradient.国家自然科学基金项目( 20606027)

Expression of uPARAP/ Endo180 and Its Clinical Significance in Nasopharyngeal Carcinoma

[中文文摘]目的:探讨尿激酶型纤维蛋白溶酶原激活剂相关蛋白(uPAR-associated protein，uPARAP/Endo180)、uP-AR和VEGF在鼻咽癌组织中的表达及临床意义。方法:采用免疫组化SP法检测58例鼻咽癌组织和30例慢性鼻咽炎组织中uPARAP、uPAR和VEGF蛋白的表达,分析其与鼻咽癌临床病理特征的关系。结果:鼻咽癌组织中uPARAP的阳性表达见于肿瘤间质的成纤维细胞和巨噬细胞,定位于胞膜和胞质,呈棕黄色颗粒状分布;uPAR阳性染色定位于肿瘤细胞与间质细胞胞浆内;VEGF阳性染色定位于肿瘤细胞胞浆内。鼻咽癌组织中uPARAP、uPAR和VEGF的阳性表达率分别为75.9%、81.0%和77.6%;与慢性鼻咽炎比较,uPARAP、uPAR和VEGF在鼻咽癌组织中的阳性表达率有显著性差异(P<0.05);鼻咽癌组织中uPARAP表达与uPAR、VEGF的表达水平呈明显正相关(P<0.05);uP-ARAP在角化型鳞癌、非角化型癌和未分化癌的阳性表达率分别为42.9%、66.7%和86.1%。随着肿瘤组织类型分化程度的下降,uPARAP表达水平有上升趋势(P<0.05)。不同组织学类型之间进行两两比较发现, uPARAP 的表达也有显著性差异( P<0.05) 。uPARAP 蛋白的表达与鼻咽癌组织病理分级、颈部淋巴结转移、临床分期密切相关( P<0.05),而与患者的年龄、性别等因素无关。结论: uPARAP、uPAR 和VEGF 在鼻咽癌组织中协同表达对促进鼻咽癌的扩散转移可能起重要作用, 联合检测这些指标有望成为判断鼻咽癌恶性程度和估计患者预后的重要生物学标志。[英文文摘]Objective: To investigate the expression and clinical significance of uPARAP/Endo180(uPAR-associated protein), urokinase plasminogen activator receptor(uPAR) and vascular endothelial growth factor(VEGF) in nasopharyngeal carcinoma(NPC). Methods: Streptavidin-horseradish peroxidase immunohistochemistry(SP-IHC) method was used to detect the expression of uPARAP, uPAR and VEGF in 58 samples of NPC and 30 samples of chronic nasopharynxitis. Results: The positive expression of uPARAP in NPC was mainly confined to mesenchymal cells, including fibroblasts and macrophages. The uPARAP immunoreactivity was found as granulated diffuse cytoplasmic staining, as well as in a pattern suggesting localization on the cell surface. uPAR in NPC tissues was evenly distributed in the cytoplasm of both cancer cells and mesenchymal cells. The expression of VEGF in NPC was mainly seen in the cytoplasm of tumor cells. In the NPC tissues, the expression rate of uPARAP, uPAR and VEGF was 75.9%, 81.0%, and 77.6%, respectively (P<0.05). A significant difference was found in the expression of uPARAP, uPAR and VEGF between NPC tissues and chronic nasopharynxitis tissues. The expression of uPARAP was positively correlated with the expression of uPAR and VEGF in NPC. The positive expression rate of uPARAP was 42.9% in keratinizing NPC, 66.7% in non- keratinizing NPC, and 86.1% in undifferentiated carcinoma.The expression of uPARAP was associated with the differentiation of NPC. The expression of uPARAP was significantly different among different pathological types of NPC(P<0.05). The expression of uPARAP in nasopharyngeal carcinoma was significantly correlated with pathological classification, tumor grade, cervical lymph node metastases and clinical.福建省自然科学基金资助(编号:C0610045

软颗粒饲料对“红膏蟹”培育生长、存活和营养成分的影响

将平均体质量(453.6±46.91)g、已交配的健康锯缘青蟹饲养在36cm×26cm×27cm塑料箱中,投喂由鲜杂鱼糜加淀粉、电解多维粉末和卡拉胶制得的软颗粒饲料,培育锯缘青蟹\"红膏蟹\"。试验结果表明,29~31d育成\"红膏蟹\";投喂软颗粒饲料的青蟹肌肉占比(59.89%~60.84%)显著低于投喂冰鲜杂鱼和贝类的青蟹(P<0.05),但培育成活率(96.9%~97.1%)、质量增加率(67.26%~69.47%)、特定增长率(1.39%/d~1.53%/d)、可食部分(65.67%~66.32%)和红膏占比(17.36%~17.68%)均显著高于投喂冰鲜杂鱼和贝类的青蟹(P<0.05);软颗粒饲料组\"红膏蟹\"肌肉中粗蛋白、脂肪和水分的含量分别为19.9%、0.8%和75.1%,生殖腺中粗蛋白、脂肪和水分含量分别为30.59%、14.50%和54.69%,肌肉和生殖腺中必需氨基酸的含量分别为5.59%和8.14%,呈味氨基酸的含量分别为6.50%和9.90%,氨基酸评分分别为71.7和100,肌肉和生殖腺中饱和脂肪酸总量分别为44.0%和49.2%,单不饱和脂肪酸总量分别为24.6%和29.2%,多不饱和脂肪酸总量分别为27.9%和15.7%;投喂软颗粒饲料提高了青蟹肌肉中粗蛋白的含量和青蟹的营养价值。福建省星火项目(2016S0055);;福建省公益性项目(2018R1037-1);;2017年宁德市现代渔业结构调整资金资助项目(宁财农指[017]65号);;宁德师范学院科研发展资金资助项目(2016FZ24

约束经营者“道德风险”的博弈分析

国家自然科学基金项目(70272014

“蟹公寓”培育红膏蟹养殖技术研究

红膏蟹为青蟹生长发育的风味好、营养价值最高的特殊阶段（卵巢成熟发育的青蟹通常称为红膏蟹）,其价格也为普通青蟹的2倍以上,且市场上通常供不应求,但目前存在培育成活率低、养殖设施设备差等问题。因此,本文研究了一种青蟹培育红膏蟹的专用设备——“蟹公寓”,旨在为实现工厂化培育红膏蟹养殖模式和青蟹产业的可持续发展提供现实的生产经验和理论依据