MCNP在核医学方面的应用概况

随着计算机技术的快速发展,蒙特卡罗方法在核医学中的应用越来越广泛。概述了MCNP的基本信息,介绍了其发展情况。以MCNP5为基础,阐述了其在核医学方面应用,介绍了近年来MCNP医学物理几何数据库发展情况,同时对MCNP6的一些新特性进行了研究。     

核子微探针在医学和生物学中的应用

生命科学中微量元素研究需要发展一种能在细胞水平上测量生物组织中元素分布的仪器或技术,核子微探针的发展使这种研究成为可能。本文简述了核子微探针的最新发展及其在医学、细胞药物学和细胞谱系中的某些应用。     

锝与诊断核医学

诊断核医学是放射性核素在医学诊断中应用的科学。核诊断的基本条件之一是放射性药物。放射性元素锝具有优良的核物理特性,极适合诊断使用。目前应用最广最重要的是99mTc标记的放射性药物。锝是过渡金属元素,化学性质十分活泼,具有很强的络合能力。应用99Mo──99mTc发生器可以很容易得到Na99mTcO4。用氯化亚锡可将99mTcO4-还原至低价态,经与特定的络合剂络合可制成各种99mTc—络合物。将这些99mTc络合物作为放射性药物引入人体,可选择性地使某些脏器组织显像,以诊断疾病。     

元素成像技术在核法证中的应用研究进展

核法证学是打击非法贩卖核材料和放射性物质的重要工具,可用于对截获的材料进行分析溯源。过去的研究主要集中于元素和同位素特征的总体分析表征。近年来,随着微分析技术的发展,微米尺度和纳米尺度元素和同位素空间分布特征、微观形态学特征研究正成为核法证学研究的热点。本文基于近年来国内外核法证学的研究成果,详细介绍了元素成像技术在核法证学材料分析领域元素和同位素成像、微观形态学方面的应用研究进展。     

核药物发展小记

简要回顾了20世纪70年代以来核药物领域发展的主要成就,并对目前在临床上应用最为广泛的核药物探针[18F]FDG作了重点介绍。[18F]FDG的发展可追溯至20世纪20年代,历经半个世纪终于成功应用于临床,在肿瘤、神经退行性疾病、心血管疾病的诊断中发挥了巨大作用。除此以外,本文也介绍了多肽类及蛋白类核药物的最新进展。在梳理核药物发展脉络的同时,本文也借此机会向读者介绍了几位为核药物发展做出巨大贡献的科学家,并作为晚辈向其致以崇高的敬意。最终,笔者希望向读者阐明核药物研究立足基础研究、面向临床问题的学科特色,也希望读者能通过对经典核药物发展脉络的了解,对自身的科学研究有所启发。     

Establishing Radiolanthanum Chemistry for Targeted Nuclear Medicine Applications

We report the first targeted nuclear medicine application of the lanthanum radionuclides ^132/135La. These isotopes represent a matched pair for diagnosis via the positron emissions of ¹³²La and therapy mediated by the Auger electron emissions of ¹³⁵La. We identify two effective chelators, known as DO3Apic and macropa, for these radionuclides. The 18-membered macrocycle, macropa, bound ^132/135La with better molar activity than DO3Apic under similar conditions. These chelators were conjugated to the prostate-specific membrane antigen (PSMA)-targeting agent DUPA to assess the use of radiolanthanum for in vivo imaging. The ^132/135La-labeled targeted constructs showed high uptake in tumor xenografts expressing PSMA. This study validates the use of these radioactive lanthanum isotopes for imaging applications and motivates future work to assess the therapeutic effects of the Auger electron emissions of ¹³⁵La.     

Porphyrins as Chelating Agents for Molecular Imaging in Nuclear Medicine

Porphyrin ligands, showing a significant affinity for cancer cells, also have the ability to chelate metallic radioisotopes to form potential diagnostic radiopharmaceuticals. They can be applied in single-photon emission computed tomography (SPECT) and positron emission tomography (PET) to evaluate metabolic changes in the human body for tumor diagnostics. The aim of this paper is to present a short overview of the main metallic radionuclides complexed by porphyrin ligands and used in these techniques. These chelation reactions are discussed in terms of the complexation conditions and kinetics and the complex stability.     

纺织纤维发展历程概观

人类在纺织材料的应用上历经了从天然纤维到化学合成纤维的发展道路。毛、麻、棉、丝是人类最早使用的天然纺织纤维。19世纪末,随着现代化学和化学工业的兴起,人类迎来了化学合成纤维的新时代。20世纪50年代以后,伴随着现代石油化学工业的快速发展,人类开启了以聚酯纤维等为代表的高分子合成纤维新时代。20世纪中后期,新型高性能的复合纺织纤维逐渐成为现代纺织材料发展的新方向。     

DNA‐Templated Copper Nanoprobes: Overview,Feature, Application,and Current Development in Detection Technologies

Metal nanoprobes have recently attracted board research interestinr their application in establishing sensing systems due to their unique optical, electrical, physical, and chemical properties. In comparison to gold and silver nanoprobes, analytical platform based on copper nanoprobes (Cu‐NPs) is still in the early stages of development. In this review, we focus on single‐stranded, and double‐stranded DNA capped Cu‐NPs sensing systems which have been designed for various analytes, including metal ions, anions, small molecules, biomolecules (DNA, RNA, and protein, etc.). In addition, the application of Cu‐NPs in biological labeling or bio‐imaging platforms has also been introduced and summarized.     

PAMAM Dendrimer‐Based Nanodevices for Nuclear Medicine Applications

Nuclear medicine, involving nuclear medicine imaging and radiotherapy (RT), has become a mainstay of theranostics in the field of nanomedicine and several examples have been successfully translated into clinical practice. The combination of radionuclides with dendrimers has long been investigated in nuclear imaging, such as positron emission tomography (PET) and single‐photon emission computed tomography (SPECT), providing functional information for whole body quantitative analysis with high sensitivity due to the unique structural advantages of the dendrimer platform. Besides, radioisotopes with both therapeutic and imaging functionalities can also be combined with dendrimer platforms for theranostic applications. In this review, the recent advances in the development of radionuclide‐labeled poly(amidoamine) dendrimer‐based nanodevices for targeted PET, SPECT, SPECT/computed tomography, SPECT/magnetic resonance imaging of tumors, RT, as well as for SPECT‐imaging‐guided RT of cancer are summarized. Current restrictions hindering the clinical translation of dendrimer‐based nuclear nanodevices and future prospects are also discussed.     

电化学DNA传感器的研制及其医学应用

对近几年发展起来的电化学DNA传感器的研究工作进行了讨沦,详细论述了该类传感器的工作原理、探针固定化技术、杂交指示剂的类型以及在基因诊断、药物分析等方面的医学应用,并展望了应用前景和发展方向。     

Estimation of background interference in prompt-gamma neutron activation using MCNP

Prompt-gamma neutron activation (PGNA) is used to measure total-bodynitrogen and hydrogen in humans. Background interference in the gamma spectraarises from both subject and shielding. A Monte Carlo simulation program (MCNP4B2)was used to examine the neutron and gamma signals in the PGNA system ( ²⁴¹AmBe source). N and H peak regions were assessed in the presenceand absence of calibration phantoms. The simulations suggested extracorporealH peak contributions of up to 30%, depending on subject body habitus. MostN background could be attributed to detector pileup events. The MCNP resultsallowed us to improve shielding design and develop background correction algorithmsto improve measurement precision.     

多媒体教学课件《原子核与原子核反应》的研制

本文简要介绍了多媒体教学课件《原子核与原子核反应》的内容 ,开发环境和影像数字化技术及其在多媒体课件中的应用等     

砷、锑、铋类药物的应用历史和现状

近年来,由于对主族元素砷、锑、铋的生物功能研究的不断深入,人们已经从仅仅关注它们对人体的生物毒性到开始研究它们在化学药物领域的应用和潜力。本文简要的介绍了砷、锑、铋作为药物应用的历史,综述了近年来砷、锑、铋的化合物在抗癌、治疗白血病、抗寄生虫病和抗菌方面的一些应用,以及用于发现这些药物的靶分子和结合蛋白的现代生物技术。     

烟草植物在有机医药和农药中的应用

烟草植物富含优质蛋白质和生物碱,具有很高的药用价值。对近年来烟草植物在有机医药、农药方面的应用进行了总结,对烟草的应用前景进行了展望。     

Utilization of Physiologically Based Pharmacokinetic Modeling in Pharmacokinetic Study of Natural Medicine: An Overview

Natural medicine has been widely used for clinical treatment and health care in many countries and regions. Additionally, extracting active ingredients from traditional Chinese medicine and other natural plants, defining their chemical structure and pharmacological effects, and screening potential druggable candidates are also uprising directions in new drug research and development. Physiologically based pharmacokinetic (PBPK) modeling is a mathematical modeling technique that simulates the absorption, distribution, metabolism, and elimination of drugs in various tissues and organs in vivo based on physiological and anatomical characteristics and physicochemical properties. PBPK modeling in drug research and development has gradually been recognized by regulatory authorities in recent years, including the U.S. Food and Drug Administration. This review summarizes the general situation and shortcomings of the current research on the pharmacokinetics of natural medicine and introduces the concept and the advantages of the PBPK model in the study of pharmacokinetics of natural medicine. Finally, the pharmacokinetic studies of natural medicine using the PBPK models are summed up, followed by discussions on the applications of PBPK modeling to the enzyme-mediated pharmacokinetic changes, special populations, new drug research and development, and new indication adding for natural medicine. This paper aims to provide a novel strategy for the preclinical research and clinical use of natural medicine.     

Advantages of mesh tallying in MCNP5 for soil analysis calculations

The Monte Carlo code, MCNP5, includes a mesh and lattice tally option useful for large matrix calculations. Recently, a fast lattice tally (FLT) was developed for MCNPX. We used these two codes to model an in-situ soil analysis system based on inelastic neutron scattering. The tallies were utilized to calculate the reaction rates of fast neutrons with carbon via inelastic reactions. The results of these three tallies and their respective computational times are compared, and the advantages of these methodologies discussed.     

Design and testing of a neutron porosity probe using MCNP code

A neutron porosity probe has been designed. The MCNP Monte Carlo code has been utilized to determine the various parameters of the probe. The probe response was simulated and compared with the experimental results with good agreement. Preliminary fieldwork was performed with acceptable data. This revised version was published online in July 2006 with corrections to the Cover Date.     

Experimental and MCNP calculations of neutron flux parameters in irradiation channel at Es-Salam reactor

The Algerian research reactor (Es-Salam) is a 15 MW heavy water reactor type, operating since 1992. It became essential to characterize the neutron field in the most useful irradiation positions, in order to guarantee the accuracy in the application of k ₀-neutron activation analysis (k ₀-NAA). Experimental value of the thermal to epithermal neutron flux ratio (f) and of the deviation of the epithermal neutron spectrum from 1/E shape (α) were determined using different methods. This work focuses the verification of Monte Carlo neutron flux calculation in typical irradiation channel. Comparison of the results for parameter f obtained experimentally and by Monte Carlo simulations shows good agreement in the irradiation channel studied. The difference between both results is about 2.08%.