131I标记多肽YP13聚乙二醇修饰物及其生物分布

利用噬菌体展示技术, 对荷人结肠癌CL-187裸鼠进行体内筛选, 获得在肿瘤组织中富集的一条十二肽SVSVGMLPSHAP. 为了标记131I, 在N端连接酪氨酸合成了十三肽YP13(YSVSVGMLPSHAP). 另外, 利用单甲基化聚乙二醇(mPEG5000)对YP13进行化学修饰. RP-HPLC分离纯化YP13、mPEG-YP13和对照随机十三肽YR13(YEDIKPKTSLAFR) 131I标记产物, 放化纯度大于95%. RP-HPLC分析131I-YP13和131I-mPEG-YP13体内循环60 min后的血清, 结果显示, 131I-mPEG-YP13体内稳定性优于131I-YP13. 这三种标记物在荷人结肠癌CL-187裸鼠体内的分布表明, 131I-YP13和131I-mPEG-YP13在1和2 h时的肿瘤摄取远远高于对照肽131I-YR13, 二者的瘤血比随时间的延长而升高. 131I-mPEG-YP13在肿瘤中的摄取随着时间的延长有所改善. 因此, 放射性碘标记的多肽YP13及其聚乙二醇修饰物可能成为新型结肠癌显像剂.     

(AIN)+n和(AIN)-n(n = 1~15) 团簇的结构与稳定性

用密度泛函理论(DFT)的B3LYP方法, 在6-31G*水平上, 对(AIN)⁺_n和(AIN)^-_n(n = 1~15) 团簇的几何构型、红外光谱和热力学稳定性进行了研究, 并对它们的电离能及电子亲和能进行了讨论. 结果表明: (AIN)_n团簇的电荷状态对簇合物的结构有较大影响, 随着n的增大影响逐渐减小; 所有平衡结构中不存在Al-Al和N-N键, Al-N键是惟一键型;(AIN)⁺_n和(AIN)^-_n结构稳定性幻数与(AIN)_n相同, 即n = 2, 4, 6, …等偶数结构较为稳定; (AlN)₁₀团簇具有最大的电离能(IP = 9.14 eV)和最小的电子亲和能(EA = 0.19 eV), 较其他团簇更稳定.     

丙泊酚微乳注射液血浆蛋白结合率的测定

采用Beagel犬血浆平衡透析法,高效液相色谱法测定丙泊酚微乳注射液与Beagel犬血浆蛋白结合率。色谱柱:Agilent C18柱(5μm,4.6 mm×150 mm);流动相:0.01 mol/L乙酸铵(pH 7.0):乙腈=20:80(V/V);紫外检测波长:215 nm。丙泊酚在5～600 ng/mL范围内线性关系良好。丙泊酚微乳注射液在质量浓度为50、400、1000 ng/mL时与血浆蛋白结合率分别为(96.97±0.52)%、(97.73±0.76)%、(97.74±0.58)%。HPLC法能较好的应用于丙泊酚微乳注射液血浆蛋白结合率的测定,丙泊酚微乳注射液具有较高强度的血浆蛋白结合率。     

卤化银添加剂对125I在北山花岗岩岩粉中的吸附作用研究

利用柱法实验和批次实验研究了卤化银(AgCl、AgBr、AgI)对¹²⁵I在甘肃北山花岗岩中的吸附现象。结果表明在无载体的情况下,卤化银添加剂有利于¹²⁵I在北山花岗岩岩粉中的吸附,有效分配系数(K_d,e)均大于1.0×10³ mL·g^-1。在有载体的情况下,氯化银和溴化银仍然对¹²⁵I在北山花岗岩岩粉中有良好的吸附作用,K_d,e大于1.0×10³ mL·g^-1。其中,溴化银的吸附效果最好,这可能与其晶体结构和光解性质有关。     

毛细管电泳电化学发光用于丙吡胺及其与血浆蛋白结合率的测定

本实验利用透析袋平衡透析、毛细管电泳Ru(bpy)2+3电化学发光检测技术测定了丙吡胺和人血浆蛋白的结合率.在恒电位1.3 V;进样电压10 kV持续10 s,分离电压15 kV,运行缓冲液30 mmol/L 磷酸盐缓冲液(pH 7.5),检测池中为5 mmol/L Ru(bpy)2+3 稀释于50 mmol/L 磷酸盐缓冲液(pH 7.5)中等最优化的条件下,丙吡胺的检出限为10 μmol/L(S/N=3).对蛋白结合率的测定结果表明,人血浆中的药物浓度为1.6～8.2 mmol/L,丙吡胺与血浆蛋白的结合是呈线性的,其线性回归方程为y=-0.07+0.93x,线性相关系数r为0.9999,丙吡胺与人血浆蛋白的结合率约为90.4%.     

YAG∶Ce体系中稀土离子掺杂对Ce3+的光谱性能的影响

采用高温固相法合成了一系列的(Y0.95Ln0.01Ce0.04)3Al5O12(简称YAG∶Ce,Ln), 系统地研究了此体系中的Ln3+对Ce3+的发光强度的影响. 结果表明, 在YAG∶Ce的体系中, La3+, Gd3+, Lu3+等光学透明离子的少量掺杂对Ce3+的发光强度的影响不大; 掺入少量的Pr3+, Sm3+, Tb3+, Dy3+, Ho3+, Er3+, Tm3+等稀土离子, 由于它们的能级与Ce3+的能级有交叠, 使它们之间存在着竞争吸收或能量转移, 对Ce3+的发光有较明显的变化, 其中, Pr3+和Sm3+的掺入使其在红光区有发射峰, 可以增加YAG∶Ce的红色成分以提高显色性; Nd3+, Eu3+和Yb3+对Ce3+的发光有严重的猝灭作用.     

离子对反相液相色谱同时测定家兔血浆中的外源性磷酸肌酸及其代谢产物肌酸

建立了离子对反相高效液相色谱法(IP-RP-HPLC)同时测定家兔血浆中外源性磷酸肌酸(PCr)及其代谢产物肌酸(Cr)的方法,用于研究外源性PCr在家兔体内的药代动力学。以含离子对试剂四丁基硫酸氢铵(TBA)的磷酸盐缓冲液-甲醇为流动相,在Kromasil-C18色谱柱上进行梯度洗脱。采用内标法定量、以基线扣除法计算外源性PCr和Cr的浓度。PCr和Cr的线性范围分别为10～7500 mg/L和10～1500 mg/L;日内和日间精密度均≤6.2%,准确度分别为99.7%~102.2%和96.5%~102.4%;萃取回收率均大于92%。静脉注射PCr后,血浆中PCr的消除为二室模型,消除半衰期为(20.4±2.7) min;表观分布容积为(0.179±0.037) L/kg;清除率为(0.019±0.002) L/(kg\5min);静脉注射PCr后血浆中迅即出现降解产物Cr,其达峰时间为30 min;消除半衰期为(43.7±4.5) min。本方法的专属性强,准确度和精密度高,能特异性地测定家兔血浆中的PCr和Cr。实际应用结果表明,该方法完全符合PCr药代动力学生物分析方法学的要求。     

Ce3+对菠菜D1/D2/Cytb559复合物影响的光谱学研究

从Ce³⁺处理过的菠菜PSⅡ颗粒中纯化出了D1/D2/Cytb559复合物并研究了Ce³⁺对其光谱学性质的影响. 结果表明Ce³⁺处理过的菠菜生长发育改善, PSⅡ颗粒电子传递效率明显加快, D1/D2/Cytb559复合物UV-Vis 谱在Soret区和Q区分别蓝移3和2 nm; 荧光发射峰蓝移5 nm; EXAFS谱表明Ce³⁺已结合到D1/D2/Cytb559复合物上. 推测Ce³⁺已同时参与叶绿素卟啉环中N的配位和多肽氨基酸羧基氧的配位, Ce—N键长为0.253 nm, Ce—O键长为0.32 nm. CD谱表明Ce³⁺结合后其复合物二级结构未发生明显变化. 认为Ce³⁺加强了D1/D2/Cytb559复合物P680⁺原初电子供体的功能, 但对反应中心复合物的构象影响不大.     

金属氯化物对硼氢化钠还原α-氯代苯乙酮的影响

用NaBH₄还原α-氯代苯乙酮制备相应的β-氯代-α-苯乙醇时, 在较高的反应温度下产生许多副产物, 钙、镧、镁、锰、锌等金属氯化物的存在能有效抑制副反应的发生, 高产率地得到产物.     

添加C10H10Cl2Ti对6LiBH4-CaH2-3MgH2体系储氢性能的影响

C_(10)H_(10)Cl_2Ti的添加可以有效改善6LiBH_4-CaH_2-3MgH_2样品吸放氢性能,添加的质量分数为5%时具有较好的催化效果。样品的起始和终止放氢温度比原始样品分别降低约30和25℃,可逆储氢量(质量分数)约为8.1%。添加C_(10)H_(10)Cl_2Ti催化剂的样品在360℃下等温放氢速率比原始样品提高了178%。两步放氢反应的表观活化能分别为131.4和138.8 kJ·mol~(-1),相比原始样品降低了约18.6%和15.8%。利用X射线光电子能谱(X-ray photoelectron spectroscopy,XPS)对样品进行分析发现,热分解过程中C_(10)H_(10)Cl_2Ti生成了多价态的Ti化合物,催化了LiBH_4与CaH_2的反应,从而改善了复合体系的储氢性能。     

Measurement of Glucose Concentration in Blood Plasma Based on a Wireless Magnetoelastic Biosensor

Abstract

A wireless magnetoelastic glucose biosensor in blood plasma is described, based on using a mass sensitive magnetoelastic sensor as transducer. The glucose biosensor was fabricated by coating the ribbon‐like, magnetoelastic sensor with a pH sensitive polymer and a biolayer of glucose oxidase (GOx) and catalase. The pH response polymer swells or shrinks, thereby changing sensor mass loading, respectively, in response to increase or decrease of pH values. The GOx–catalyzed oxidation of the glucose in blood plasma produces gluconic acid, resulting in the pH sensitive polymer shrinking, which in turn decreases the sensor mass loading. The results show that the proposed magnetoelastic glucose biosensor can be successfully applied to determine the concentration of glucose in blood plasma. At glucose concentration range of 2.5–20.0 mmol/l, the biosensor responses are reversible and linear, with a detection limit of 1.2 mmol/l. Since no physical connections between the sensor and the monitoring instruments are required, this proposed biosensor can potentially be applied to in vivo and in situ measurement of glucose concentration in physiological fluids.     

Effect of dry density on 125I diffusion in GMZ bentonite

Gaomiaozi(GMZ) bentonite is regarded as the favorable candidate backfilling material for a potential repository in China.It is important to understand the diffusion behavior of 125 I in GMZ bentonite and compare the diffusion behavior in GMZ and other types of bentonite like MX-80,Avonlea,etc.Therefore,through-and out-diffusion experiments were conducted to obtain the effective diffusion coefficient(D e) and distribution coefficient(K d).A computer code named Fitting for diffusion coefficient(FDP) was used for the experimental data processing and theoretical modeling.At the dry density of GMZ bentonite from 1600-2000 kg/m 3,the D e values of 125 I were(2.4-20.4) × 10-12 m 2 /s and K d values were constants.At dry density above 1800 kg/m 3,the diffusion behaviors were almost the same,indicating that the anion exclusion was ineffective.Out-diffusion results showed that the species of 125 I may be changed during the diffusion processing.It was probably caused by some organic matters or reducing substances in GMZ bentonite.Since the main composition of bentonite is montmorillonite,similar diffusion parameters were obtained in GMZ and other types of bentonite.The relationship of D e and accessible porosity(acc) could be described by Archie’s law with exponent n = 1.2-2.8 for 125 I diffusion in bentonite,whereas n = 2.0 in GMZ bentonite.Furthermore,bentonite with the dry density of 1800 kg/m 3 was proposed as the backfilling materials used in the construction of high level radioactivity waste repository.     

胶束毛细管电泳在线推扫富集技术测定血液中环丙沙星含量

采用在线Sweeping(推扫 )富集技术 ,建立了胶束毛细管电泳法测定血液中痕量乳酸环丙沙星的方法。考察了背景溶液pH值、SDS浓度、进样时间、血样预处理方法等对乳酸环丙沙星富集效果的影响。使用未涂层的毛细管柱 (5 5cm× 75 μmi.d .,有效柱长 4 7cm) ,30mmol/L硼砂 +80mmol/L十二烷基硫酸钠 (pH =9.4 0 )为背景溶液 ,在紫外检测波长 2 5 4nm、运行电压 1 8kV条件下 ,血浆样品用乙腈除蛋白后直接在线Sweep ing富集 ,富集倍数可达 6 0 0倍。线性范围在 0 .0 4～ 1 0mg/L (r =0 .999,n =8)。检出限为 0 .0 1mg/L。本方法减少了样品预处理的繁琐过程 ,弥补了毛细管电泳 (CE)在测定血液中痕量组分方面的不足 ,为CE在体内痕量药物分析等方面的应用提供了新的方法     

基于启发式方法和支持向量机方法预测药物与人血浆蛋白结合率

应用启发式方法和支持向量机方法建立了70种药物与血浆蛋白结合率的定量构效关系模型, 研究了分子结构对药物与血浆蛋白结合率的影响. 两种方法均得到了较好的结果, 交互检验的相关系数平方分别为0.80和0.82; 通过对模型的稳定性和预测能力比较, 支持向量机建立的QSAR模型能够更好地预测药物与血浆蛋白结合率.     

一元弱酸(碱)溶液稀释过程中离子浓度递变幅度的相对非均等性

对一元弱酸（碱）溶液稀释过程中各种离子浓度递变幅度的相对非均等进行研究,推出了离子浓度递变幅度的大小次序排列及其相关概念,这一研究,有助于从整体上把握离子浓度递变规律,为正确判断离子浓度的变化结果提供了理论依据。     

Optimization of the Design and Operating Conditions of an Amperometric Biosensor for Glutamate Concentration Measurements in the Blood Plasma

Today, the concentration of glutamate in the patient′s blood is an important indicator in medical diagnostics; therefore, it is necessary to have a simple, accurate, and fast tool to obtain the data. Here, a recently developed amperometric glutamate-sensitive biosensor was optimized to improve its characteristics. The platinum disk electrode was used as a transducer. As a bioselective element we used the enzyme glutamate oxidase, covalently crosslinked with bovine serum albumin by glutaraldehyde. Circumstances of enzyme immobilization on the transducer‘s surface were optimized (enzyme and glutaraldehyde concentrations and immobilization duration). To test the ability of this biosensor to work in biological environments containing complex biological substances, the influence of the working solution was investigated (concentration of the working buffer, its temperature, presence of the protein in the analyzed sample). The linear range of biosensor was from 5 to 600 μM of glutamate and the sensitivity was 150–200 nA/mM. Measurements of glutamate concentrations in the blood plasma were performed by biosensor and glutamate dehydrogenase assay. The linear correlation between the methods was found in a range of 50.4–182.5 μM (R²=0.99). Thus, it has been shown that the developed biosensor makes it possible to measure the concentration of glutamate in blood plasma.     

离子对反相高效液相色谱法同时测定大鼠血浆和红细胞中外源性磷酸肌酸及其代谢产物和相关三磷酸腺苷

建立了离子对反相高效液相色谱(IP-RPHPLC)同时测定大鼠血浆和红细胞(RBC)中磷酸肌酸(PCr)及其代谢产物肌酸(Cr)以及相关三磷酸腺苷(ATP)浓度的方法.采用Kromasil-C18色谱柱(250 mm×4.6 mm,5 μm),流动相A:0.2%KH2PO4+0.08%四丁基硫酸氢铵混合溶液(pH 3....     

高效毛细管电泳前沿分析法研究酸性药物那格列奈与人血浆白蛋白的结合

用高效毛细管电泳前沿分析法研究了酸性药物那格列奈与人血浆白蛋白的结合常数、结合位点和结合率。使用未涂层的毛细管柱 (4 0cm× 5 0 μmi.d .;有效柱长 32cm) ,磷酸盐缓冲溶液 (pH 7.4 ,离子强度0 .17)为背景溶液 ,在紫外检测波长 2 14nm、运行电压 18kV和重力进样 10 0s的条件下 ,利用那格列奈谱峰的平台高度和游离药物浓度的良好线性关系 (r>0 .999,n =6 ) ,测定了那格列奈的游离药物浓度。固定药物浓度 (2 0 0 μmol L ,2 5 0 μmol L) ,考察不同的蛋白质浓度对结合的影响 ;固定蛋白质浓度 (10 0 μmol L) ,考察不同的药物浓度对结合的影响。实验数据采用非线性拟和程序进行处理 ,得到了那格列奈的蛋白质结合参数。高效毛细管电泳前沿分析法测定的数据重现性良好 (RSD <2 .5 % ,n =3) ,在药代动力学和药效学研究方面具有简便、准确的优点。     

Evaluation of procedures for solid-phase extraction of [125I]-methodone from serum on to discs and cartridges

Summary Biological samples must be purified before chromatography to eliminate interfering compounds. Discs have recently been developed to enhance the performance of solid-phase extraction (SPE) and reduce solvent consumption. This type of support is available in all the bonded-phases typically found in conventional packed SPE devices. The process for solid-phase extraction of [¹²⁵I]-methadone from water and serum (i.e. retention and losses of [¹²⁵I]-methadone during sample loading, washing, elution, etc.) has been studied to determine the behaviour of this compound on several extracting supports. For serum solutions we observed significant matrix effects on discs because of their low capacity. This resulted in loss of [¹²⁵I]-methadone during the loading step because the contact time between the analyte and the functional groups of the support was too short. Although mixed-mode discs, which have both hydrophobic and cation-exchange extraction mechanisms, do not perform as well as conventional cartridges, they can, nevertheless, be used before liquid chromatographic analysis because of their several mechanical and economical advantages in comparison with cartridges.     

Evaluation of Drug Interaction in Binding to Protein by High Performance Liquid Chromatography

Drugs in the body are bound to metabolizing enzymes, targets/receptors and transport proteins in certain extent. The binding of drugs to targets or receptors is mainly specific and responsible for its pharmacological and therapeutic effects. The metabolizing of drugs by enzyme involves both