克拉霉素胶囊的NMR定量方法研究

以核磁共振技术测定克拉霉素胶囊的含量为例,建立了核磁共振测定药物制剂含量的分析方法. 结果得到克拉霉素在1.03~24.72 mg/mL范围内具有良好线性关系,回归方程为： y=0.025 1X-0.026, r=0.999 2;平均回收率为98.7%(n=9). 测定结果的误差小于0.2%. 本方法具有灵敏度高、方法简单、重现性好的优点,可作为克拉霉素胶囊剂以及其他药物制剂的含量测定方法.      

克拉霉素与醌茜素的荷移反应及其测定

克拉霉素与醌茜素在乙醇 -水介质中发生电荷转移反应 ,形成 1∶ 1的电荷转移络合物。该络合物在5 80 nm处有最大吸收 ,表观摩尔吸光系数为 3.74× 1 0 3 L·mol-1· cm-1 ,稳定常数是 2 .6× 1 0 5。建立了一种快速测定克拉霉素的荷移分光光度法。药物浓度在 0— 1 0 0 mg/ L范围内服从比耳定律。本法测定了克拉霉素制剂中有效成分的含量 ,与文献法结果基本吻合。     

Li_4SiO_4陶瓷小球水解吸行为实验研究

采用程序升温热解吸(TPD/TDS)方法对Li4SiO4陶瓷小球的水解吸行为进行了实验研究。结果表明:水解吸过程中主要存在四个解吸峰;其中100℃附近的峰可解释为物理吸附水;150,250,400℃附近的峰可分别解释为以氢键、Li-OH和Si-OH配位键形式存在的化学吸附水。氚的释放与水的解吸几乎同步进行,且氚的释放形式主要为氚水(HTO),据此推测,氚水可能存在三种释放机制:(1)-OT+H2O→-OH+HTO;(2)-OH+-OH→H2O,-OT+H2O→-OH+HTO;(3)-OT+-OH→HTO。     

键合型PU/Eu(Cit)Phen荧光纳米纤维制备与表征

合成了含-OH(羟基)的Eu(Cit)Phen(铕-柠檬酸-邻菲咯啉)三元配合物与端-NCO(异氰酸酯)基PU(聚氨酯)预聚物,通过一OH与一NCO间加成反应及l,3.丙二醇扩链反应制备键合型PU/Complex稀土高分子材料,将其溶液经静电纺丝制得具有荧光性能的纳米纤维.采用FT-IR、SEM、XRD、DSC和PL对...     

电子束脱硫副产物含硫量的测试分析

电子束烟气脱硫脱硝副产物成分十分复杂，主要为(NH4)2SO4和NH4NO3，还含有少量(NH4)2SO3、NH4NO2、(NH4)2S、NH4SO3NH2、有机胺、SiO2、铁锈和其他金属氧化物。若作为复合肥使用，应建立相应的测定手段对其各项指标进行测试，检验是否符合国家标准。本文用两种方法对脱硫副产物的含硫量进行了分析测试。     

臭氧修饰(001)晶面TiO_2纳米片及其光催化降解甲苯研究（英文）

本文系统研究了臭氧修饰对(001)主导晶面锐钛矿型TiO_2光催化剂降解甲苯性能的影响.利用自行搭建的光催化VOCs降解装置对催化剂光降解甲苯的性能进行了测试.通过多种表征手段,结合原位DRIFTS和DFT计算研究了臭氧表面修饰及甲苯吸附和降解机理.结果表明,用臭氧进行表面修饰可以显著提高(001)主导晶面TiO_2光催化降解甲苯的性能.(001)晶面上丰富的5c-Ti不饱和配位是臭氧分子的吸附位点,其解离后形成的Ti-O键与H_2O分子结合,在表面生成大量孤立的Ti_(5c)-OH.Ti_(5c)-OH是甲苯分子的吸附位,它的形成显著提高了对甲苯分子的吸附能力.在光照下Ti_(5c)-OH与光生空穴结合能形成·OH自由基.通过臭氧解离产生的O_2也可以与光生电子结合形成超氧自由基.这些具有强氧化性活性自由基的形成促进了对气相甲苯的光催化降解速率.     

紫外光辐照聚乙烯醇的1H NMR研究

用¹H NMR谱,自旋-晶格弛豫时间（T₁）和X-射线衍射研究了聚乙烯醇(PVA)在紫外光（UV）辐照后-OH基团与溶剂中残余水质子间氢键的生成与质子交换. 结果表明随着UV光辐照时间的增长,水峰与-OH质子峰逐渐相互靠近,同时水峰逐渐变宽,向低场方向移动,这与-OH基团与溶剂DMSO中残余水的质子之间既有氢键生成又有质子交换有关. 对辐照前后的PVA的DMSO溶液进行变温氢谱的研究,表明随着温度的升高,二者的-OH基团共振峰均逐渐变弱,溶剂残余水峰与-OH基团峰逐渐移向高场. PVA辐照前后随着浓度增大,羟基质子峰“变钝”. 辐照后的PVA的X-射线衍射表明聚集态结构中部分分子间氢键受到了破坏.     

紫杉醇水凝胶成胶因子延缓微管蛋白聚集

Paclitaxel (PTX) is one of the most efficient anticancer drugs for the treatment of cancers through β-tubulin-binding. Our previous work indicated that a PTX-derivative hydroge-lator Fmoc-Phe-Phe-Lys(paclitaxel)-Tyr(H₂PO₃)-OH (1)could promote neuron branching but the underlying mechanism remains unclear. Using tubulin assembly-disassembly assay, in this work, we found that compound 1 obviously delayed more microtubule aggregation than PTX did. Under the catalysis of alkaline phosphatase, Fmoc-Phe-Phe-Lys(paclitaxel)-Tyr(H₂PO₃)-OH could self-assemble into nanofiber Fmoc-Phe-Phe-Lys(paclitaxel)-Tyr-OH with width comparable to the size of αβ-tubulin dimer. Therefore, we proposed in this work that nanofiber Fmoc-Phe-Phe-Lys(paclitaxel)-Tyr-OH not only inhibits the αβ-tubulin dimer binding to each other but also interferes with the plus end aggregation of microtubule. This work provides a new mechanism of the inhibition of microtubule formation by a PTX-derivative hydrogelator.     

南极海冰细菌胞外多糖的助凝作用及红外光谱分析

利用酒精沉淀结合氯仿和丁醇脱蛋白法,从南极海冰细菌Pseudoaheromonas sp.Bsi20310发酵液中制备得到该菌株所产的胞外多糖(Exopolysaccharide,Bsi20310 EPS)粗品.以Bsi20310 EPS为助凝剂,可以明显改善铁盐对模拟水溶性染料活性艳红X-3B废水的混凝效果,在pH 10左右,Fe(Ⅲ)浓度0.98 mmol·L-1条件下加入150 mg·L-1 Bsi20310 EPS,脱色率由16%提高到84%.利用傅里叶变换红外光谱法(FTIR)分析比较Bsi20310 EPS、Fe(Ⅲ)混凝剂-Bsi20310 EPS絮体及Fe(Ⅲ)混凝剂-Bsi20310 EPS-活性艳红X-3B絮体的官能团,图谱显示,Bsi20310 EPS含有丰富的-OH、-COOH及糖苷键等活性基团;当Bsi20310 EPS与Fe(Ⅲ)混凝剂作用后,3 429 cm-1处尖峰变成宽峰,2 921 cm-1处峰形减弱或消失,1 650cm-1处锐峰变成钝峰,1 242 cm-1处峰出现轻微红移,1 151～1 038 cm-1范围内杂多峰变成单一尖峰,表明-OH、-COOH及糖苷键是发生反应的主要官能团.研究结果预示着Bsi20310 EPS可以作为一种安全有效的微生物助凝剂.     

染料分子固定基团-CN,-NH_2,-OH,-COOH,-SH在ZnO(10(1|ˉ) 0)表面吸附

采用基于第一性原理的密度泛函理论系统研究了染料分子中的-CN,-NH2,-OH,-COOH和-SH这5种固定基团在ZnO(10-1 0)表面的吸附,分析了它们在ZnO(10-1 0)表面上的吸附机制.结果表明:5种基团在ZnO(10-1 0)表面都发生了化学吸附,其中-CN、-NH2和-OH发生了非解离吸附,-COOH和-SH则是表面解离吸附.5种固定基团的吸附能分别是:-0.64eV,-1.28eV,-1.03eV,-1.21eV(-1.40eV)和-1.14eV.综上所述,以-COOH为固定基团的染料分子制备的染料敏化太阳能电池(DSSCs)具有更稳定的性能,这为ZnO染料敏化太阳能电池的设计和应用提供了理论基础.     

山东昌乐蓝宝石生长环带的FTIR和LA-ICP-MS 研究

山东昌乐蓝宝石生长环带的显微红外光谱和LA-ICP-MS研究结果表明：蓝宝石中的环带颜色成因与晶格中的-OH有相应的关系。在内部含有六边形环带的蓝宝石中,同一环带上的-OH含量相近;不同颜色环带中的-OH含量不相同,其中暗带中的-OH含量最高,过渡带次之,亮带为零;环带中-OH含量与微量元素Ti成正相关,可以用于反映蓝宝石形成过程中环境的变化。当环境中的含氢量较高时,会有较多的Ti4+-Fe2+对替代Al3+进入蓝宝石晶格;当环境中的含氢量较低时,则较少或者没有Ti4+-Fe2+对替代Al3+进入蓝宝石晶格;充分考虑蓝宝石晶格中-OH的分布特征,有利于为蓝宝石的呈色机理研究、高品质蓝宝石合成与优化等提供新的科学思路。     

吡喃酮类化合物与镱配合物的红外和拉曼光谱研究

采用非水体系中牺牲金属阳极的电化学方法分别合成了稀土金属镱与 3 羟基黄酮及 3 羟基 2 甲基 γ 吡喃酮的配合物。对配合物进行了IR和Raman光谱测定。两种光谱提供了互为补充的信息 ,配体经配位后—OH的伸缩振动谱峰消失 ,部分相关的谱峰频率发生了明显位移 ,特别是羰基伸缩振动红移十分明显 ,在Raman光谱的低波数区间检测到可指认为金属和配体键合的伸缩振动。根据这两种光谱的研究结果推断了所得配合物的可能结构。     

Immobilization of bovine serum albumin on TiO2 film via chemisorption of H3PO4 interface and effects on platelets adhesion

In the present study, bovine serum albumin (BSA) was successfully covalently immobilized on the surface of anatase TiO₂ film by a three-step method, i.e. application of H₃PO₄ chemisorption to increase surface -OH, which increases the amount of coupling 3-aminopropyl-triethoxylsilane (APTES), thus linking with BSA by imide bond using EDC/NHS/MES. There is no significant -OH group increase on rutile film when using the same method of phosphoric acid treatment, which suggest it is difficult for further chemical modification of the rutile film. After covalent immobilization of BSA on anatase film, an improved hemocompatibility of anti-platelet adhesion and aggregation in vitro could be recognized by LDH and SEM analysis. This study suggests BSA-immobilized anatase surface can serve as hemocompatibility material in vivo.     

Effects of enhanced hydrogen bonding on the mechanical properties of poly (vinyl alcohol)/carbon nanotubes nanocomposites

In this study, poly (vinyl alcohol) (PVA) composites reinforced by multiwall carbon nanotubes (MWCNTs) functionalized with either phenolic hydroxyl groups (MWCNTs-f-OH) or PVP molecule (PVP@MWCNTs) were fabricated. The objective was to elucidate the effect of different MWCNTs surface functionalization on the mechanical properties of the nanocomposites. It was found that both of PVP@MWCNTs and MWCNTs-f-OH had a good dispersion in PVA matrix. However, the MWCNTs-f-OH had stronger effective interfacial interaction with PVA matrix than PVP@MWCNTs, owe to the formation of hydrogen bonds between MWCNTs-f-OH and PVA. The stress-strain measurements showed that the Young’s modulus and tensile strength of MWCNTs-f-OH/PVA with only 1.0 wt.% contents increased by 200 and 100% compare with that of PVA, respectively. The findings of this experimental study emphasized the critical role of MWCNTs surface morphology in determining the mechanical properties of nanocomposites, and shed new light on understanding and advancing the properties of carbon nanotube based composites.     

Energy barriers for trimethylaluminum reaction with varying surface hydroxyl density

Energy barriers for trimethylaluminum (TMA) reaction with varying surface hydroxyl (-OH) density were investigated using density functional theory. When the surface -OH density increased from 0 to 6.8/nm² on Si (0 0 1) surfaces, the energy barrier for TMA reaction with the surfaces decreased due to attractive interactions between TMA and -OH. When the surface -OH density further increased to 9.2/nm² on a-SiO₂ (0 0 1) surfaces, however, the trend was reversed. This was because the attractive interactions between TMA and -OH were decreased due to the attractive interactions of -OH's themselves via hydrogen bond at this high surface -OH density.     

Photophysical Properties of Some Flavones Probes in Homogeneous Media

Photophysical properties of five hydroxyflavones (HF) (some typical models of flavonols), (3 - HF, 6 - HF, 7-HF, 3, 6 - diHF and 3, 7 - diHF) were studied in homogeneous media by means of UV–vis and steady-state and time resolved fluorescence spectroscopies. Their absorption and fluorescence characteristics based on the flavonols structure are presented and discussed. It was found that the fluorescence of the flavonols depends on the nature of the solvent and on their molecular structure, especially on the position and the number of the -OH groups of the substituted phenyl ring. Attention is paid to the number of the -OH groups that influence the excited-state intramolecular proton transfer (ESIPT) process. The fluorescence quantum yield and the lifetime of the flavonols in heterogeneous media have been also determined. The results are discussed with relevance to the flavonols as sensitive fluorescence probe and to their microenvironments in the systems of biological interest and especially in a typical protein environment.     

The Electric Field Gradient of 111Ag in Macrocyclic Crown Thioethers

Time differential perturbed angular correlation experiments and ab-initio density functional theory calculation were used to determine the electric field gradients of the metal centres of the macrocyclic crown thioethers Ag(15S5)[BF₄], Ag(18S6-CH₂OH)[CF₃SO₃], Ag(18S6)⁺, Ag(19S6-OH)[Tosylat] and Ag(20S6-OH)[CF₃SO₃]. The density functional theory calculations have been performed with the Amsterdam Density Functional code ADF. A “fingerprint system” is introduced, which allows to assign electric field gradients to certain Ag coordinations in these crown thioether complexes.     

Quantitative assessment of surface functionality effects on microglial uptake and retention of PAMAM dendrimers

Dendrimers are a promising class of polymeric nanoparticles for delivery of therapeutics and diagnostics. Polyamidoamine (PAMAM) dendrimers have shown significant efficacy in many animal models, with performance dependent on surface functionalities. Understanding the effects of end groups on biological interactions is critical for rational design of dendrimer-mediated therapies. In this study, we quantify the cellular trafficking kinetics (endocytosis and exocytosis) of generation 4 neutral (D4-OH), cationic (D4-NH₂), anionic (D3.5-COOH), and generation 6 neutral (D6-OH) PAMAM dendrimers to investigate the nanoscale effects of surface functionality and size on cellular interactions. Resting and LPS-activated microglia were studied due to their central roles in dendrimer therapies for central nervous system disorders. D4-OH exhibits greater cellular uptake and lower retention than the larger D6-OH. D4-OH and D3.5-COOH exhibit similar trafficking kinetics, while D4-NH₂ exhibits significant membrane interactions, resulting in faster cell association but lower internalization. Cationic charge may also enhance vesicular escape for greater cellular retention and preferential partitioning to nuclei. LPS activation further improves uptake of dendrimers, with smaller and cationic dendrimers experiencing the greatest increases in uptake compared to resting microglia. These studies have implications for the dependence of trafficking pathway on dendrimer properties and inform the design of dendrimer constructs tailored to specific therapeutic needs. Cationic dendrimers are ideal for delivering genetic materials to nuclei, but toxicity may be a limiting factor. Smaller, neutral dendrimers are best suited for delivering high levels of therapeutics in acute neuroinflammation, while larger or cationic dendrimers provide robust retention for sustained release of therapeutics in longer-term diseases.     

液体水中的自由OH及其结构改变

液体水中自由OH的确认对理解液体水的微观结构非常重要. 通过随温度变化的水的拉曼光谱分析其相对强度的变化及退偏比,发现了自由-OH存在的直接证据,结果显示虽然液体水从5 oC到85 oC结构发生明显变化,但是自由-OH的含量几乎不变,且含量非常少,约为3%. 这表明了氢键从四氢键形式断裂时更容易发生在氢键受体部位.