金属结合硫蛋白在TRIS-醋酸缓冲体系中的电喷雾质谱表征研究

金属硫蛋白(metallothionein,MT)是一类对重金属离子(如Zn2+、Cd2+、Hg2+等)有很强亲和力,含丰富半胱氨酸的低分子质量蛋白质。金属结合硫蛋白的电喷雾质谱表征通常是在接近中性条件下采用电喷雾正离子检测模式进行的,然而在该条件下由于MT的离子化效率低而导致检测灵敏度低。选择TRIS-醋酸作为缓冲体系,在中性条件下采用负离子模式实现了对Zn7-MT-2a的灵敏检测。同时考察了可能影响负离子响应的因素,包括溶液的pH值和TRIS-醋酸的浓度。结果表明,在考察范围内采用较低的pH值和较高浓度的TRIS-醋酸均有利于金属结合硫蛋白电喷雾质谱信号强度的增加。

弱光和Tris处理条件下PSⅡ放氧核心复合物的损伤

弱光条件下 (12 0 μmol·m- 2 ·s- 1)用Tris (0 .8mol/L ,pH 6 .5～ 10 .0 )处理具有放氧活性的PSⅡ核心复合物 ,可引起 33kD锰稳定蛋白的释放和锰复合物的破坏 ,并导致核心复合物的结构发生明显的改变 .温和电泳、SDS PAGE和双向电泳分析表明 ,主要是PSⅡ核心复合物的二聚体和单体减少 ,并且复合物部分解体 ;除反应中心D1和D2 蛋白外 ,核心天线CP4 3和CP4 7的量也减少 ,33kD锰稳定蛋白要发生降解 .避光时 。

几种常用的核染色标记物pH 6.0 Citrate和pH 9.0 Tris/EDTA修复液的比较

目的探讨pH 6.0 Citrate和pH 9.0 Tris/EDTA两种修复液在常用的免疫组化核染色标记物中的染色效果。方法选取本科室常用的3种核/浆标记抗体以及22种核标记抗体分别采用pH 6.0 Citrate和pH 9.0 Tris/EDTA微波热修复进行比较。结果在25种抗体中,其中有11种分别用pH 6.0 Citrate和pH 9.0 Tris/EDTA微波修复染色效果基本一致,在其余14种抗体中,有11种用pH 9.0 Tris/EDTA微波热修复方法进行修复时,阳性信号明显增强;而有3种抗体用pH 6.0 Citrate微波热修复方法进行修复时,阳性信号稍增强。结论对于这25种抗体来说,如果用微波加热的方法进行抗原修复,那么pH 9.0 Tris/EDTA优于PH 6.0 Citrate。

Tris对高LET碳重离子辐照下质粒DNA链断裂的保护作用

利用100 keV/μm碳离子束(初始能量为290 MeV/u)照射溶解于纯水、10 mmol/L Tris、1 mmol/L EDTA及TE缓冲液中的pUC19质粒DNA。通过琼脂糖凝胶电泳技术分析了不同溶液中各种形态DNA分子所占份额,并计算得到不同剂量下平均每个质粒分子中单链断裂(SSB)及双链断裂(DSB)的数目。发现Tris通过抑制SSB和DSB的产生对碳重离子辐照下的质粒DNA有明显的保护作用,而EDTA能够加剧SSB的产生而抑制DSB的形成。

TRISO钍铀包覆燃料颗粒裂变气体生成规律

三结构同向性型(Tri-structural iso-tropic,TRISO)包覆燃料颗粒产生的裂变气体是影响燃料元件安全性的一个重要因素。本工作利用ORIGEN计算程序,研究了基于热堆的TRISO包覆燃料颗粒中裂变气体氙和氪的积累随中子能谱和中子通量的变化规律。计算结果表明,中子能谱、通量和运行时间均相同时,【O2包覆颗粒中氙的生成龄为氪的约7倍,ThO2包覆颗粒中氙的生成量约为氪的4.5倍。研究了ThO2包覆颗粒裂变气体饱和值与能谱的关系,结果表明,能谱越软,越易达到饱和,但能谱较软时达到的饱和值较小。通过对裂变气体积累量的计算估计了ThO2包覆颗粒因内压导致破损的寿命值。

TRIS饱和酚一步法提取食用菌DNA

[目的]为探索食用菌子实体DNA的快速提取方法。[方法]以4种广泛栽培的食用菌子实体为材料,采用改进的TRIS饱和酚法提取食用菌基因组DNA,并用琼脂糖凝胶电泳和PCR技术检测提取DNA样品的质量。[结果]获得的食用菌DNA质量较好,能够满足PCR等后续分子生物学试验。[结论]TRIS饱和酚法是一种简单、快速提取食用菌DNA的方法。

Thickness Dependent Behavior of Photoluminescence of Tris(8-hydroxyquinoline)Aluminum Film

In situ thickness dependent photoluminescence （PL） measurements of tris（8-hydroxyquinoline） aluminum（Alq3） film were performed. At the beginning of Alq3 deposition on the glass substrate, the Alq3 emission showed a sharp red-shift. Further deposition of Alq3 resulted slight red-shift, and finally tended to saturated value. The total red-shift of about 12 nm was observed for the Alq3 film thickness range from 2 to 500 nm.This red-shift was attributed to the change from the 2D to 3D exciton state with increasing Alq3 film thickness. Meanwhile, the PL intensity of Alq3 emission increased continuously, and showed a rate change at the initial deposition of Alq3 due to non-rediative decay of excitons arised from the interaction between excitons and the substrate, and finally tended to saturation with the Alq3 thickness.

Tris缓冲体系下NiTi表面制备聚多巴胺薄膜提高其耐蚀性能

Tris缓冲体系下,通过在NiTi表面包裹聚多巴胺薄膜来提高其耐腐蚀性能。研究分别在10mMTris pH=8.5和50mMTris p H=8.5条件下,改变多巴胺的初始浓度,考察了成膜后的NiTi耐蚀性能。结果表明,10mM的Tris体系下,聚多巴胺修饰NiTi的耐蚀性能并不是随着多巴胺的浓度增加而增强;相比之下,50mM的Tris体系下,聚多巴胺修饰NiTi的耐腐蚀性能随着多巴胺浓度的增加而增强。

用于戴瑞奶绵羊精液冷冻的Tris稀释液优化研究

为了解决戴瑞奶绵羊冷冻精液质量偏低的问题,试验采集3只健康的24月龄戴瑞种公羊精液,分别用含0,40,80,120,160μmol/L白藜芦醇(RES)抗氧化剂的Tris稀释液稀释后冷冻,通过测定和计算冷冻前和冷冻后精液的精子活力、质膜完整率、顶体完整率、精子畸形率和抗氧化性能[丙二醛(MDA)含量、谷胱甘肽过氧化物酶(GSH-Px)活性和总抗氧化能力(T-AOC)]来确定RES的最适添加浓度。结果表明:80μmol/L RES添加量的精子活力、质膜完整率、顶体完整率均最高,平均值分别为(61.36±3.45)%、(40.31±1.20)%、(54.08±2.27)%;其中精子活力、质膜完整率均极显著高于0,160μmol/L添加量(P<0.01),显著高于40,120μmol/L添加量(P<0.05);顶体完整率与40μmol/L添加量差异不显著(P>0.05),极显著高于160μmol/L添加量(P<0.01),显著高于0,120μmol/L添加量(P<0.05)。80μmol/L添加量的精子畸形率和MDA含量最低,平均值分别为(14.27±0.69)%和(31.98±0.85)μmol/L;其中精子畸形率与40μmol/L添加量差异不显著(P>0.05),极显著低于0,160μmol/L(P<0.01),显著低于120μmol/L添加量(P<0.05)。80μmol/L添加量的精子MDA含量与120μmol/L添加量差异不显著(P>0.05),极显著低于0,40μmol/L添加量(P<0.01),显著低于160μmol/L添加量(P<0.05)。80μmol/L添加量精子T-AOC和GSH-Px活性最高,平均值分别为(770.21±4.54)μmol/L和(65.49±1.29)U/mg,均极显著高于0,40,160μmol/L添加量(P<0.01),显著高于120μmol/L添加量(P<0.05)。说明在Tris稀释液中添加80μmol/L RES更适用于奶绵羊精液冷冻保存。

Ring-opening Polymerization ofε-Caprolactone Using Lanthanide Tris(4-tert-butylphenolate)s as a Single-component Initiator

The ring-opening polymerization of e-caprolactone (CL) initiated by novel single lanthanide tris(4-tert-butylphenolate)s [Ln(OTBP)3] is reported. Single-component La(OTBP)3 can effectively prepare polycaprolactone (PCL) with over 90% yield and viscosity average molecular weight about 60 x 10 under quite mild conditions: molar ratio of CL to initiator is 1000, 60 C, 2 h in toluene. Mechanism study indicates that the monomer inserts into the growing chain via the break of acyl-oxygen bond of CL.

SYNTHESIS，PROPERTY AND HEAT STABILITY FO RPOLYVINYLCHLORIDSOFANTIMONYTRIS（MERCAPTOACIDESTER）

Antimony mercaplde heat stabilizer for polyvinyl chlorideis synthesized from antimony trioxide and mercaptocarboxylic acid esters, HS(CH2).COoi-C8H17 (n=1～2) at 100～115 C In the presence of 0. 5%～1 % an organic acid catalyst. Some physicochemicalconstants of the compounds, such as density and refractive index, aredetermined. The complexes are hydrolabll in aqueous solutions andthe bond of Sb-S is weaker than that of Sb-o. The forming bondproperty of antimony tris (mercaptoacid ester ) has been elucidatedby measurement of infrared spectra in comparison with mercaptocarboxylic acid esters. The polyvinyl chloride resins containing antimony mercaptide heat stabilizers, do not darken at elevated temperatures and exhibit a high degree of stability. It is proposed that mercaptocarboxylic acid ester freeradicals can esterify PVC microradicals at carbon atoms with upaired electrons.

Adjusting the solvation structure with tris(trimethylsilyl)borate additive to improve the performance of LNCM half cells

Tris(trimethylsilyl)borate(TMSB) has been intensively studied to improve the performances of lithiumion batteries. However, it is still an interesting issue needed to be resolved for the research on the Li^(+) solvation structure affected by TMSB additive. Herein, the electrochemical tests, quantum chemistry calculations, potential-resolved in-situ electrochemical impedance spectroscopy measurements and surface analyses were used to explore the effects of Li^(+) solvation structure with TMSB additive on the formation of the cathode electrolyte interface(CEI) film in LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)/Li half cells. The results reveal that the TMSB additive is easy to complex with Li^(+) ion, thus weaken the intermolecular force between Li^(+) ions and ethylene carbonate solvent, which is benefit for the cycle performance. Besides, the changed Li^(+) solvation structure results in a thin and dense CEI film containing compounds with Si–O and B–O bonds which is favorable to the transfer of Li^(+) ions. As a result, the performances of the LNCM811/Li half cells are effectively improved. This research provides a new idea to construct a high-performance CEI film by adjusting the Li^(+) solvation structures.

Polymerization of n-Hexyl Isocyanate Initiated by Novel Rare Earth Tris(2,6-di-tert-butyl-4-methylphenolate)

The polymerization of n-hexyl isocyanate(HNCO) was carried out in the presence of a novel single initiator, rare earth tris(2,6-di-tert-butyl-4-methylphenolate)[Ln(OAr)_3]. The influences of reaction conditions such as the monomer concentration, the polymerization temperature and time, and the types of solvents on the polymerization of HNCO were studied. Polymerizations of phenyl, i-propyl, p-tolyl, n-butyl and n-octyl isocyanates with La(OAr)_3 were also examined.

Luminescence study of europium(III) tris(β-diketonato)/phosphonate complexes in chloroform

The extraction of Eu（Ⅲ） with β-diketone, HA, and monodentate or bidentate Lewis bases, B, into chloroform and the luminescence properties of the extracted species were studied. Pivaloyltrifluoroacetone, Hpta, and 2-thenoyltfifluoroacetone, Htta, were used as the β-diketones. The Lewis bases, B, were tetraethyl methylene diphosphonate, POPO, which was bidentate, and diethyl benzylphosphonate, PhPO which was monodentate. Based on the extraction data, the stability constants, log β, of the first complexes between tfis（β-diketonato）Eu（Ⅲ） and the phosphonate, EuA3B, were determined to be 6.0 for the POPO complex and 3.40 for the PhPO complex. The Eu（Ⅲ） luminescence intensity in the EuA3POPO was larger than EuA3 where A was either pta or tta at similar concentrations of Eu（Ⅲ）, while that in Eu（pta）3PhPO was stronger than EuA3; however, in Eu（tta）3PhPO, it was weaker than Eu（tta）3. The POPO functions as a sensitizer, and the PhPO functions as a quencher for the tta chelate and as a sensitizer for the pta chelate. From the lifetime and quantum yield, φ, of the Eu（Ⅲ） luminescence in the complexes as well as the observation of the extractability of Eu（Ⅲ） with the Hpta and the phosphonates and of the luminescence spectra of the complexes, it was confirmed that the extraction of Eu（Ⅲ） was remarkably enhanced with a β-diketonate and a strong Lewis base, and also the ternary complex that was formed as the extracted species, showed luminescence enhancement. This phenomenon may be due the formation of a strong bond between the Eu（Ⅲ） and the strong Lewis base leading to more hydrophobicity in the extracted species and also to more effective energy transfer from the Lewis base to the Eu（Ⅲ）. It was not significant whether the donor atoms were N or O.

硫酸铵—Tris改进剂石墨炉原子吸收光谱法测定镉

拟订了测定环境及生物样品中镉的平台石墨炉原子吸收光谱法。用硫酸铵和三羟甲基氨基甲烷(简称Tris)作为化学改进剂。在该混合改进剂的存在下,镉的允许灰化温度提高到850℃,与(NH_4)_3PO_4-Mg(NO_3)_2或(NH_4)_2HPO_4-HPO_3作改进剂相比,测镉的灵敏度也得到改善。研究了稳定作用机理。

RING-OPENING POLYMERIZATION OF l,4-DIOXAN-2-ONE INITIATED BY LANTHANUM TRIS(2,6-DI-TERT-BUTYL-4-METHYLPHENOLATE)

The ring-opening polymerization of 1,4-dioxan-2-one （PDO） was carried out by lanthanum tris（2,6-di-tert-butyl-4- methylphenolate） （La（OAr）3） as novel single component initiaLor. The influences of polymerization reaction temperature and the molar ratio of monomer to initiator on the monomer conversion and molecular weight of poly（1,4-dioxan-2-one） （PPDO） were explored. PPDO with high viscosity average molecular weight of 1.95×10^5 can be prepared at 40℃ when [PDO]/ [La（OAr）3] molar ratio was 800. Mechanism investigation shows that the polymerization proceeds through a ＂coordination- insertion＂ mechanism with selective rupture of acyl-oxygen be,nd of PDO.

Optical properties for N,N’-bis (lnaphyhly)N,N’-diphenyl-1,1’-biphenyl-4,4’-diamine and tris (8-hydroxyquinolinato) aluminum in organic light emitting devices

The optical properties of N,N’-bis (Inaphthyl)N,N’-diphenyl-1,1’-biphenyl-4,4’-diamine (NPB) and tris (8-hydroxyquinolinato) aluminum (Alq3) organic materials used as hole transport and electron transport layers in organic light-emitting devices (OLED) have been investigated. The NPB and Alq3 layers were prepared using thermal evaporation method. The results show that the energy band gap of Alq3 is thickness independence while the energy band gap of NPB decreases with the increasing of sample thickness. For the case of photoluminescence the Alq3 with thickness of 84 nm shows the highest relative intensity peak at 510 nm.

Synthesis and Spectroscopic Characterizations of the Mono-and Bimolecular Iron(Ⅲ)Complexes by the Interaction With Tris Buffer in Neutralized Media:Biological and Morphological Investigations

The reaction of iron(Ⅲ)anions,FeCl 3 and Fe 2(SO 4)3 with tris(hydroxymethyl)aminomethane(Tris)in a 1∶2 molar ratio affords the new coordination compounds NH 4[Fe 2(Tris)2(H 2O)4(SO 4)](Ⅰ)and NH 4[Fe(Tris)2(H 2O)2](Ⅱ).These compounds were characterized by elemental analysis,and their molecular structures were determined by spectroscopic methods(infrared and electronic spectra),magnetic susceptibility,and molar conductivity measurements,and further corroborated by thermo gravimetric analysis and its differential(TGA/DrTGA).According to the experimental data,the complexes can be characterized in the solid state as mono-and binuclear,with a distorted octahedral stereochemistry.The distorted octahedral stereochemistry adopted by the complexes was confirmed by the magnetic susceptibility measurement of NH 4[Fe 2(Tris)2(H 2O)4(SO 4)],which consists of a six-coordinate iron atoms in a distorted octahedral environment constructed from four O atoms(two Tris molecules),two O atoms from the loosely associated SO 4 coordinated ligand,and O,N of second Tris molecule with occupying by four oxygen atoms of coordinated water molecules.Regarding,NH 4[Fe(Tris)2(H 2O)2]complex the mono iron atom is surrounded by six oxygen atoms as four by two Tris molecules and two coordinated water molecules in axial form.Antibacterial and anticancer activities of the complexes were studied and the complexes were screened against bacteria,colorectal adenocarcinoma(Caco-2)and breast cancer(Mcf-7)cell lines.

Synthesis and Relaxation Properties of Lanthanide(Gd ,Yb) Complexeswith Tris Modified DTPA

Synthesis and characterization of NMR T-1 relaxation properties of the title complexes and several transition metal-EDTA-bis[ tris(hydroxymethyl methylamide] complexes were performed for searching new contrast agents for magnetic resonance imaging(MRI). The ligands, abbr. to DTPA-BTris and EDTA-BTris, were obtained by modifying DTPA and EDTA with tris(hydroxymethyl) aminomethane. It was found that the relaxivities of solutions of the modified complexes in vitro are correspondingly greater than those of the parent complexes. For GdDTPA-BTris, MnEDTA-BTris, and FeEDTA-BTris, the relaxometry of lattice relaxation(R-1) is 5.4, 3.1, and 1.9 L.mmol(-1).s(-1) vs. 5.2, 2.8 and 1.7 L.mmol(-1).s(-1) for GdDTPA, MnEDTA, and FeEDTA, respectively. Additionally, the present complexes have the favorable properties such as high water solubility and chemical stability required of clinical useful contrast agent.

Comparative Proteomics Based on 18O Labeling to Evaluate the Hepatotoxicity of Tris（2,3-dibromopropyl） Isocyanuratein Rats

Detecting protein expression levels in organisms exposed to environmental pollutants can help us understand the action mechanism of toxicity. In the present study, adult female Sprague-Dawley (SD) rats received a consecutive intraperitoneal injection of tris(2,3-dibromopropyl) isocyanurate (TBC) for seven days, and the ^16O/^18O labeling comparative proteomic approach was used to study the change of liver proteome in these rats. Thirty six differential proteins were identified between the control group and the high-dose-exposed group (8 mg/kg), of which, twenty eight proteins were down-regulated and eight proteins were up-regulated. Bioinformatics analysis revealed that most of the differential proteins were related with the metabolic and cellular processes. In addition, the contents of malondialdehyde (MDA), catalase (CAT), and glutathione (GSH) in liver were measured to evaluate the oxidative stress status induced by TBC exposure. Together, these findings showed that TBC might be toxic to liver by disrupting metabolic process and apoptosis. The results might provide a better insight into the mechanism of toxicity induced by TBC.