Preparation of β-methyl p-iodophenyl pentadecanoic acid(BMIPP) and ^125I-BMIPP

A method with several steps superior to literature has been developed for the preparation of β-methyl p-iodophenyl pentadecanoic acid (BMIPP),The synthesis and physical properties of BMIPP are described.It is characterized by IR,^1HNMR, elemental analysis and MS,^125I-BMIPP can be prepared by three methods:direct labeling,slid-state transfer labeling and Cu(Ⅰ) assisted labeling,Cu(Ⅰ） assisted labeling is simple and not necessary to purify before clincal use,It can fulfil the requirements for kit labeling.     

Preparation of ^11C labelled tamoxifen

The syntheses and HPLC analysis of N-desmethyltamoxifen and carbon11 labelled tamoxifen are described.In order to obtain the N-desmethyltamoxifen,tamoxifen citrate was first converted to tamoxifen free base.N-desmethyltamoxifen was prepared by reacting tamoxifen free base with 1-chloroethyl-chloroformate(ACE.C1). For ^11C labeling,N-desmethyltamoxifen was heated with ^11C methyl iodide for 10min at 130℃,and the 11C labelled compund was purified by HPLC on a μBonapak TM C18 column,Injectable ^11C-tamoxifen was obtained within 50-60 min from EOB (end-of -bombardment)with a labeling yield of 60%-70%.     

Formation of a potential tumor therapeutic pharmaceutical ^186Re—bleomycin

The influence of experimental conditions on the formation of 186Re-bleomycin (BLM) was studied.The results show that the labeling yield is mainly dependent on the pH value in reaction medium and gluconate can effectively protect the re-oxidation of Re reduced by sn(II),A better method for preparing ^186Re-BLM is described with labeling yield up to 95% in the pH range from 3.0 to 4.5.     

GEANT4 simulation of the characteristic gamma-ray spectrum of TNT under soil induced by DT neutrons

The characteristic gamma-ray spectrum of TNT in the soil induced by DT neutrons is measured by the PFTNA demining system. The GEANT4 toolkit is used to simulate the whole experimental procedure. The simulated spectra are compared with the experimental spectra, and they are mainly consistent. The share of the background sources such as neutrons and gamma is obtained and the contribution that the experimental apparatus to the background, such as shielding, detector sleeve and moderator, is analyzed. The effective gamma signal(from soil and TNT) is 29% of the full spectrum signal, and the background signal, more than 68%, this is mainly produced by shielding and the detector sleeve. By gradually optimizing the shielding and the cadmium sheet of the detector sleeve, the share of the effective gamma signal increases to 47%, and the background signal reduces to 18%.     

Preclinical pharmacological study on ^125I—IPPA

Myocardial uptake of ^125I-IPPA in rats showed a Peak of 4.4% of injected dose per gram.The half elimination time of myocardium was 3.8min and the maximal uptake of thyroid is only 0.005%ID/organ at 120min.The initial half time of 2.7min in rabbits was obtained from the elimination curve of radioactivity in blood.In vitro binding test for 125I-IPPA to HSA showed rather constant level of activation during two hours.The second peak of extraction was observed in major organs of rats,in rabbits‘ elimination of radioacivity and in binding test for 125I-IPPA to ablumin in vivo.Toxicity trial was up to standard.The tolerance of a mouse to IPPA was 560 times as high as that of a person to IPPA,It demonstrated that ^125I-IPPA could be quickly exptracted by myocardium,and its catabolites were excreted in the urine with almost no iodine loss.All the results were found to agree with the expectations based on the principal metabolic path of phenyl fatty acid.     

The Modified Friction and Diffusion Coefficients of Fokker-Planck Equation and Relaxation Rates for Non-Maxwellian Scattering

In this paper, a new method to derive the Fokker-Planck coefficients defined by a non-Maxwellian velocity distribution function for the field particles is presented. The three- fold integral and the new Debye cutoff parameter, which were introduced by CHANG and LI, are applied. Therefore, divergence difficulties and the customary replacement of relative velocity g by thermal velocity vth are naturally avoided. The probability function P（v, Av） for non- Maxwellian scattering is derived by the method of choosing velocity transfer Av, which is a true measure of collision intensity, as an independent variable. The method enables the difference between small-angle scattering and small-momentum-transfer collisions of the inverse-square force to be well clarified. With the help of the probability function, the Fokker-Planck coefficients are obtained by a normal original Fokker-Planck approach. The friction and diffusion coefficients of the Fokker-Planck equation are modified for non-Maxwellian scattering and are used to investigate the relaxation processes for the weakly coupled plasma. The profiles of the relaxation rates show that the slowing down and deflection processes are weakened in the conditions of non-Maxwellian scattering.     

Interactions between multiple filaments and bacterial biofilms on the surface of an apple

In this paper, the interactions between two dielectric barrier discharge(DBD) filaments and three bacterial biofilms are simulated. The modeling of a DBD streamer is studied by means of 2D finite element calculation. The model is described by the proper governing equations of air DBD at atmospheric pressure and room temperature. The electric field in the computing domain and the self-consistent transportation of reactive species between a cathode and biofilms on the surface of an apple are realized by solving a Poisson equation and continuity equations. The electron temperature is solved by the electron energy conservation equation. The conductivity and permittivity of bacterial biofilms are considered, and the shapes of the bacterial biofilms are irregular in the uncertainty and randomness of colony growth. The distribution of the electrons suggests that two plasma channels divide into three plasma channels when the streamer are 1 mm from the biofilms. The toe-shapes of the biofilms and the simultaneous effect of two streamer heads result in a high electric field around the biofilms, therefore the stronger ionization facilitates the major part of two streamers combined into one streamer and three streamers arise.The distribution of the reactive oxygen species and the reactive nitrogen species captured by time fluences are non-uniform due to the toe-shaped bacterial biofilms. However, the plasma can intrude into the cavities in the adjacent biofilms due to the μm-scale mean free path. The two streamers case has a larger treatment area and realizes the simultaneous treatment of three biofilms compared with one streamer case.     

Numerical Simulation of Modified Radial Electric Field by LHCD

Based on the electron‘s radial force equilibrium, the profiles of radial electric field in OH and LHCD phase are calculated by using a simulation code. The dependences of radial electron field on electron density and its profile and different current ratio, Irf/Ip, are given. The connections between the improvement of plasma confinement and the modified radial electric field by LHCD are discussed by comparing the calculated results with the experimental results.     

Experimental Investigation on Airfoil Shock Control by Plasma Aerodynamic Actuation

An experimental investigation on airfoil （NACA64-215） shock control is performed by plasma aerodynamic actuation in a supersonic tunnel （Ma -= 2）. The results of schlieren and pressure measurement show that when plasma aerodynamic actuation is applied, the position moves forward and the intensity of shock at the head of the airfoil weakens. With the increase in actuating voltage, the total pressure measured at the head of the airfoil increases, which means that the shock intensity decreases and the control effect increases. The best actuation effect is caused by upwind-direction actuation with a magnetic field, and then downwind-direction actuation with a magnetic field, while the control effect of aerodynamic actuation without a magnetic field is the most inconspicuous. The mean intensity of the normal shock at the head of the airfoil is relatively decreased by 16.33%, and the normal shock intensity is relatively reduced by 27.5% when 1000 V actuating voltage and upwind-direction actuation are applied with a magnetic field. This paper theoretically analyzes the Joule heating effect generated by DC discharge and the Lorentz force effect caused by the magnetic field. The discharge characteristics are compared for all kinds of actuation conditions to reveal the mechanism of shock control by plasma aerodynamic actuation.     

99Tcm标记糖肽及其在荷瘤小鼠体内的分布与代谢动力学

Glucose and galactose are conjugated to the N- mercaptoacetyl-Val-Gly-Gly (MAVGG). The glycopeptides and MAVGG are labeled with 99Tcm. The partition coefficients between octanol and water (Pow) are measured. Glycopeptides or MAVGG labeled with 99Tcm areinjected into the mice bearing S180 tumor. 10μL blood samples are withdrawn at different time points and the radioactivities are counted to calculate the effective halflife (T1/2) using a bi-exponential fit. Biodistribution is measured at 3 h postinjection and the percentage of injected dose per gram ( ID%/g ) and tumor to normal tissue ratio (T/NT) were calculated. The assigned structures were confirmed on the basis of IR, NMR and MS. The 99Tcm labeling yield 巨radiochemical purity is greater than 90%. The lgPow of 99Tcm-Glu-MAVGG, 99Tcm-Gal-MAVGG and 99Tcm-MAVGG are –1.974, –2.128 and –1.378, respectively. The T1/2αof the three labeled peptides are 24.3, 37.1, 46.3 min and T1/2β are 221.5, 158.4 and 198.4 min, respectively. The tumor uptakes at 3 h postinjection are 1.46, 1.55 and 0.67 for 99Tcm-Glu-MAVGG, 99Tcm-Gal-MAVGG and 99Tcm-MAVGG, respectively. Their T/NT for tumor over muscle are 3.74、7.38 and 3.53, respectively. The results demonstrated that after carbohydrate conjugate of peptides, the lipophilicity is decreased , the blood clearance is increased and the tumor uptake is enhanced. Of the two glucopeptides, 99Tcm-Gal-MAVGG shows faster blood clearance, higher tumor uptake and T/NT, which suggests the potential utility of 99Tcm-Gal-MAVGG as a suitable tumor imaging agent.     

3-正丁基锡-N-琥珀酰亚胺苯甲酸酯的合成及其125I标记

合成了3-正丁基锡-N-琥珀酰亚胺苯甲酸酯（ATE）和N-琥珀酰亚胺-3-碘苯甲酸酯（SIB），其产率分别为45．4％和71．4％，并用核磁、质谱、红外等对它们的结构进行了表征。对ATE进行了^125I标记，得到S^125IB，标记率可达93．0％，放化纯度〉98．0％。本方法为放射性药物碘的间接标记提供了重要参考。     

用于放射性砹(碘)标记蛋白质的偶联剂SPC的合成及表征

以5-溴烟酸为起始物，通过3步主要反应合成了一种适用于蛋白质放射性砹(碘)标记的偶联剂——5-(三正丁基锡)-3-吡啶甲酸N-琥珀酰亚胺酯(SPC)，并用核磁共振(NMR)、质谱(MS)、高效液相色谱(HPLC)等进行了表征。以该试剂为双功能偶联剂，实现了IgG的^125I标记，标记率达30％以上。标记产物在体外具有较高的稳定性。     

Annexin V的~(125)I标记及其在正常小鼠体内的分布

采用Iodogen法对Annexin V进行了125I标记,并观察了其在正常小鼠体内的分布情况。标记结果显示,125I-Annexin V标记率达94.9%,纯化后放化纯度达99%;室温放置72 h后,放化纯度仍保持在92%以上,表明其体外稳定性较好。生物分布结果显示,125I-Annexin V在肾脏中放射活性最高,其次为血液、肝脏、心、肺、脾;脑不吸收125I-Annexin V;肌肉、骨骼组织摄取亦较少;各组织、器官放射性摄取在1 h内除血液下降稍慢外,其余均有明显下降。表明125I-Annexin V适合用作核医学诊断试剂。     

123I和99Tcm标记的吲哚类σ2受体放射性示踪剂的设计、稳定化合物的合成及体外生物评价

设计了~(123)I和~(99)Tc~m标记的吲哚类σ_2受体肿瘤放射性示踪剂,合成了其稳定化合物 (Indole-I和Indole-MAMA-Re) 和标记前体(Indole-MAMA).体外受体结合分析结果表明,化合物Indole-I对σ1和σ_2受体的抑制常数K_i值分别为(0.574±0.355) μmol/L和(0.162±0.030) μmol/L(n=3),Indole-MAMA-Re对σ1和σ_2受体的抑制常数K_i值分别为(3.75±2.22) μmol/L和(7.83±4.87) μmol/L(n=3).成功制备了~(99)Tc~m-Indole-MAMA,纯化后经高效液相色谱法(HPLC)分析其放化纯大于90%.今后可在本文化合物的基础上通过结构优化,设计合成对σ_2受体具有高亲和力和选择性的吲哚类SPECT肿瘤显像剂.     

双功能偶联剂5-(三正丁基锡)-3-吡啶甲酸-N-琥珀酰亚胺酯的优化合成及其碘标记

为了改善碘标记生物分子在体内的脱碘问题,在无水无氧条件下合成了碘标记前体5-(三正丁基锡)-3-吡啶甲酸-N-琥珀酰亚胺酯（SPC）,并优化了合成条件,产率达到45%,并用核磁共振、质谱法进行了表征。在此基础上,合成了5-碘-3-吡啶甲酸-N-琥珀酰亚胺酯（SIPC）。对标记前体SPC的¹²⁵I 标记条件进行了摸索,最终标记率达到80%以上,经高效液相色谱（HPLC）分离后,放化纯度达到97％。标记后的¹²⁵I-SIPC在4℃保存24h,放化纯度仍在92％以上,稳定性良好。     

对碘苯代十五烷酸的初步动物实验

为了解脂肪代谢代像剂＾１２５Ｉ－对碘苯代十五烷酸（ＩＰＰＡ）在动物体内的分布，清除等行为，进行了＾１２５Ｉ－ＩＰＰＡ动物实验，结果表明，大鼠心肌对＾１２５Ｉ－ＩＰＰＡ的摄取高而快，最大心肌摄取值为４．４ＩＤ％／ｇ，半清除时间Ｔ１／２α＝３．８ｍｉｎ，甲状腺摄取低，至１２０ｍｉｎ，甲状腺摄取值仅为０．００５ＩＤ％／ｏｒｇａｎ。兔血药清除Ｔ１／２α＝２．７ｍｉｎ，＾１２５Ｉ－ＩＰＰＡ与小鼠体内血浆蛋白     

一种碘代二肽胺的体内外评价

为了探索前期自行合成的一种碘(131I)代二肽胺作为放射性药物的可能性,本文对其体外稳定性、亲脂性、急性毒性进行了考察。首先采用封管法对二肽胺进行了碘的标记,获得了标记率为85%左右的配合物;通过将配合物放置不同时间测量络合率的变化得到配合物的稳定性结果;采用摇瓶法来考察配合物的亲脂性;对配合物对实验动物的肝脏功能、外周血象的影响作了考察。结果说明,配合物是亲脂性的,毒性较低,3d后的脱碘率为13%左右。成功建立了VX2肝癌单发肿瘤兔模型,得到了配合物在正常小鼠和肿瘤大白兔体内的分布结果,配合物在动物模型以及在正常小鼠的体内分布趋势比较一致,配合物比较倾向于浓集于脂肪组织,在肿瘤组织中的滞留量相对较高,表现出作为肿瘤治疗药物的潜在可能性,但清除较快,可以作进一步的研究,提高标记物的体内稳定性,以延长配合物在靶向组织中的浓集时间。     

放射性核素标记DIPA-HSA的研究

介绍了用DTPA(二乙三胺五醋酸)作为双官能团螯合剂与HSA(人血白蛋白)进行偶联,以提高放射性核素标记的HSA的体内稳定性的方法。合成了DTPA酸酐,并将其以固态形式加入HSA水溶液,再经Sephadex G50凝胶柱纯化,得到DTPA-HSA。用~(114)In~m标记的方法,测定了在不同反应介质中DTPA与HSA偶联反应的偶联率。~(114)In~m由~(113)In堆照生产。在邻苯二甲酸盐(pH5)、磷酸盐、Hepes等几种缓冲体系中制备了DTPA-HSA的~(99)Tc~m标记物。小鼠体内分布实验表明,以邻苯二甲酸盐为缓冲介质制备的~(99)Tc~m标记物体内稳定性最好。当HSA浓度为15mg/ml,DTPA与HSA摩尔比(n_(DTPA)/n_(HSA))大于3,Sn~(21)-DTPA摩尔比小于0.5时,标记比较合适。     

碘在银丝上的吸附工艺研究

碘在银丝上的吸附是125Ⅰ种子源制备过程中的一个重要环节。对碘在经特殊处理的银丝上的吸附工艺进行了研究,考察了卤化剂类型、卤化时间、吸附时间、pH值、离子浓度、载体量等对吸附能力的影响,初步确定了碘在银丝上的吸附工艺。银丝的酸化:将银丝放入冷的4 mol/L HNO3溶液中,置于振荡器上酸化20 min;银丝的卤化:选择2 mol/L NaClO3作为卤化剂,卤化时间3 h左右;碘在银丝上的吸附工艺:室温、pH≈3、吸附时间30 min、载体量27.5μg,根据对源芯活度的要求来选择吸附液初始活度。     

MAG3在放射性金属标记应用中的最新研究进展

综述了利用巯乙酰基三甘氨酸(MAG3)标记的多肽的生物学特性。经MAG3形成的^99Tc^m标记物的标记率和比放射性高,体内稳定性好,与血清蛋白的非特异性结合低;经MAG3形成的^186/188Re标记物也具有良好的体内外稳定性。