分类： 化学 >> 核化学 提交时间： 2024-05-02
摘要： 背景：人表皮生长因子受体2(HER2)广泛存在于多种恶性肿瘤，且与预后不良有关。尤其在乳腺癌中，但HER2表达存在异质性，目前常用免疫组织化学和荧光原位杂交在评估HER2状态存在明显局限性。HER2受体显像有明显优势。放射性标记的模拟肽是检测HER2阳性病变的潜在选择。目的：制备一种18F标记的人表皮生长因子受体２（HER2）模拟肽显像剂18F-NFP-B2-S22-AFA（以下简称为18F-NFP-TP1296），探讨其microPET显像及生物分布。方法 采用一步法标记18F-NFP-TP1296被应用于HER2乳腺癌异种移植小鼠的PET-CT成像。在SKBR-3乳腺癌模型中进行了体外研究和MicroPET成像。结果18F-NFP-TP1296制备过程大约30分钟内完成，总标记率为1.5%，放化纯＞95%。MicroPET成像显示，SKBR-3异种肿瘤清晰可见，注射30、60和120min后，SKBR-3移植瘤摄取值分别为5.63±0.14%ID/g、6.26±0.27%ID/g和5.83±0.44%ID/g。30、60和120min肿瘤与血液和肿瘤与肌肉的比率分别为3.21±0.32、4.08±0.73和1.69±0.18；1.55±0.11、1.84±0.12和3.10±0.30。另外肺转移瘤注射后30、60和120min肿瘤的摄取值2.2%ID/g、2.5%ID/g及2.1%ID/g。结论：18F-NFP-B2-S22-AFA具有合成简便、药代动力学良好等优点，有望成为体内检测HER2状态的示踪剂，对肿瘤的鉴别诊断、分子靶向治疗及预后判断有一定的参考价值。
分类： 生物学 >> 生物物理学 分类： 化学 >> 物理化学 分类： 生物学 >> 生物物理学 提交时间： 2024-04-16
摘要： Transcription factor (TF) are proteins that regulates the transcription of genetic information from DNA to messenger RNA by binding to a specific DNA sequence.Nucleic acid-protein interactions are crucial in regulating transcription in biological systems. This work presents a quick and convenient method for constructing tight-binding models and offers physical insights into the electronic structure properties of transcription factor complexes and DNA motifs. The tight binding Hamiltonian parameters are generated using the random forest regression algorithm, which reproduces the given ab-initiolevel calculations with reasonable accuracy. We present a library of residue-level parameters derived from extensive electronic structure calculations over various possible combinations of nucleobases and amino acid side chains from high-quality DNA-protein complex structures. As an example, our approach can reasonably generate the subtle electronic structure details for the orthologous transcription factors human AP-1 and Epstein-Barr virus Zta within a few seconds on a laptop. This method potentially enhances our understanding of the electronic structure variationsof gene-protein interaction complexes, even those involving dozens of proteins and genes. We hope this study offers a powerful tool for analyzing transcription regulation mechanisms at an electronic structural level.
分类： 化学 >> 核化学 提交时间： 2024-04-09
摘要： 近年来，在核医学科建设加速发展过程中，含碘-131放射性废水暂存时间、衰变池建设等成为医院、环评机构、生态环境监管部门等十分关心的问题。《电离辐射防护与辐射源安全基本标准》（GB 18871）、《核医学辐射防护与安全要求》（HJ 1188）、《关于核医学标准相关条款咨询问题的回函》规定了衰变池中放射性废水（主要核素为碘-131）的合规排放方式。本文通过理论推导，给出了在满负荷情况下、衰变池存满时碘-131活度的理论计算公式；证明了含碘-131放射性废水三种合规的排放方式中，按GB 18871规定的排放方式排放对医院核医学科运营最为有利；提出了RJ方程组，解决了含碘-131放射性废水最小暂存时间和衰变池容量应如何确定的问题。4家医院的实际监测数据结果表明，含碘-131放射性废水暂存时间达到RJ方程组计算出的最小暂存时间后，总的碘-131排放量符合国家生态环境标准要求。以上可对医院核医学科衰变池建设、废水排放管理以及监管部门的监督检查提供明确、具体的指导。
分类： 化学 >> 应用化学 提交时间： 2024-01-23
摘要： 针对传统的配方设计方法繁琐费时、物料损耗多、优化效果差的缺陷，将拉丁超立方设计（LHD）算法与多层感知器（MLP）神经网络相结合，形成铝合金清洗剂配方优化的新方法。利用LHD算法全面探索参数空间和 MLP 神经网络的高效建模能力，成功优化了铝合金清洗剂配方。经过优化的配方，净洗力从 87.9 %，提升到 98.24 %，腐蚀量从 4.2 mg，下降到0.3 mg。对模型预测数据与实验数据进行回归直线拟合后，大于 0.98，证明预测与实验数据保持一致性。
分类： 化学 >> 化学物理学 提交时间： 2023-12-09
摘要： Based on the energy conversion of the dynamic electric effect from the solid/liquid contact double electric layer is the dynamic electromotive potential, this paper studies the static appearance and the release of the electric field energy of the solid/liquid contact double electric layer, so a special capacitor (P/L/N capacitor) of solid conductor P / polar liquid L / solid conductor N is constructed. The observations based on experiments are as follows: (i) the contact double electric layer derived from the internal potential difference polarization of the solid conductor / polar liquid is equivalent to the external electric field polarization of the ordinary capacitor. The formation process of the contact double electric layer is the spontaneous charging process of the P/L/N capacitor, and the P/L/N capacitor still shows the electric field energy of the contact double electric layer. (ii) Because the polarized external potential difference of the solid conductor / polar liquid contacting the double electric layer is always less than the internal potential difference, the short-circuit P/L/N capacitor also has a continuous electromotive force after the discharge, statically releasing the electric field energy contacting the double electric layer. (iii) The contact double electric layer of solid conductor / polar liquid is produced spontaneously caused by mutual contact, and it is also a self-organizing process of absorbing the environmental heat energy into the electric field energy of the contact double electric layer. P/L/N capacitors realize thermoelectric conversion by releasing the electric field energy of the contact double electric layer. The above-mentioned phenomenon provides the possibility for the development of self-generated capacitors and self-supplied power supply.
分类： 化学 >> 核化学 提交时间： 2023-06-13
摘要： Objective: We herein fabricated a branched structure containing AO groups on polypropylene/polyethylene spun-laced nonwoven (PP/PE SNW) fibers using grafting polymerization induced by radiation (RIGP) to improve AO utilization. Methods: The chemical structures, thermal properties, and surface morphologies of the raw and treated PP/PE SNW fibers were studied. The adsorption properties were investigated using batch adsorption experiments in simulated seawater with an initial uranium concentration of 500 gL-1 (pH 4, 25℃). Results: The maximum adsorption capacity of the adsorbent material was 137.3 mgg-1 within 24 h; moreover, the uranyl removal reached 96% within 240 min. Limitations: Only simulated seawater adsorption experiments have been conducted, and real seawater adsorption experiments are yet to be conducted. Conclusions: The adsorbent had an AO utilization rate of 1/3.5 and was stable over a pH range of 410, with good selectivity and reusability, demonstrating its potential for seawater uranium extraction.
分类： 化学 >> 核化学 提交时间： 2023-06-06
Zhang, Hang
Ao, Yin-Yong
Wang, Yue
Zhao, Shang-Jie
Sun, Jia-Yang
Zhai, Mao-Lin
Li, Jiu-Qiang
Peng, Jing
Li, Hui-Bo
摘要： N,N,N,N-Tetraoctyl diglycolamide (TODGA) is one of the most promising extractants tailored for high-level liquid radioactive waste treatment during nuclear fuel reprocessing. The -radiolysis of TODGA (0.2 mol/L) in n-dodecane (nDD) solution with and without pre-equilibrated 3.0 mol/L HNO3 was investigated using HPLC and UPLC-QTOF-MS and compared with the -radiolysis of neat TODGA in this study. With increased absorbed doses, the concentration of TODGA decreased exponentially for the studied systems. Moreover, pre-equilibration with HNO3 (3.0 mol/L) slightly influenced the -radiolysis of TODGA in nDD. Seven radiolytic products generated from the rupture of the C C, C O, and C N bonds in TODGA were identified in the studied extraction system. The influence of -radiation on TODGA/nDD for the extraction of Eu(III) was evaluated using the first combination of extraction experiments and density functional theory (DFT) calculations, in which the complexations of Eu(III) with TODGA and its radiolytic products were systematically compared. Based on the radiolysis kinetic model of TODGA, the slope curve of the distribution ratio of Eu(III) (DEu ) and the absorbed dose, and fluorescence titration analysis, the empirical equation of the absorbed dose and DEu was obtained successfully. Below 300 kGy, the experimental DEu agreed well with the obtained empirical equation for TODGA/nDD. Conversely, at a high absorbed dose, the experimental DEu was higher than the theoretical DEu based on the empirical equation because the radiolytic products of TODGA with similar coordination structures still possessed partial complexation toward Eu(III), which was confirmed by DFT calculations. This work provides a method to predict the extraction distribution ratio of an irradiated extractant system and to understand the complex extraction process.
分类： 化学 >> 核化学 提交时间： 2023-05-31
摘要： The rapid development of advanced techniques for selective and efficient U(VI) extraction from aqueous solutions is essential for addressing U(VI) environmental pollution and energy issues. Here, we share recent progress in U(VI) extraction from aqueous solutions, especially the most frequently applied techniques such as adsorption, catalysis (photocatalysis, piezocatalysis, and electrocatalysis), chemical deposition, and reduction by zero-valent metal particles. We attempt toelucidate the strategies and various mechanisms that contribute to the enhancement of selective U(VI) extraction. At the end of our review, we highlight the outlook, challenges, and prospects for the development of this field.
分类： 生物学 >> 生物物理学 分类： 材料科学 >> 生物材料 分类： 化学 >> 化学生物学 分类： 医学、药学 >> 基础医学 提交时间： 2023-02-09
摘要： Nanotechnology has provided considerable promise for the biological and medical fields, especially in the subjects of biological and medical imaging for the last two decades. Here, we outline different nanoparticles to contribute to biological and medical imaging disciplines. These concerned nanoparticles are soft nanoparticles, which are based on biomacromolecule/polymer or organic molecule components, hard nanoparticles that are derived from various inorganic components and hard-soft nanoparticles that are based on both inorganic components and biomacromolecule/polymer or organic molecule ones. We also discuss the imaging modalities in biology and medicine that various nanoparticles became involved in are: (1) optical imaging (OI), (2) computed tomography (CT), (3) magnetic resonance imaging (MRI), (4) ultrasonography (USG), (5) positron emission tomography (PET). We will also describe various nanoparticles to serve for one/some of those five modalities in biology and medicine imaging in this review paper.
分类： 化学 >> 应用化学 提交时间： 2020-03-05
摘要： [目的] 微波辅助合成具有潜在神经保护作用的梓醇全丙酰化产物（CP-6）。 [方法] 以梓醇、丙酰酐为原料，吡啶为溶剂和缚酸剂，微波辅助合成梓醇全丙酰化衍生物。CP-6经FT-IR、HRMS、NMR表征，采用MTT法筛查其神经保护活性。 [结果] 当丙酸酐与梓醇摩尔比为18，微波反应器反应温度 80 ℃，反应时间6 h, 梓醇在吡啶中浓度 25 g/L时梓醇全丙酰化产物产率可达98.51%。CP-6具有潜在的神经保护活性。 [结论] CP-6可经微波合成制得，其具有神经保护作用，是一种潜在的神经保护作用药物。
分类： 化学 >> 化学物理学 提交时间： 2018-11-28
Taixiang Liu
Ke Yang
Zhuo Zhang
Lianghong Yan
Beicong Huang
Heyang Li
Chuanchao Zhang
Xiaodong Jiang
Hongwei Yan
摘要： Large-scale, high-power laser facility is currently a basis for the research of inertial confinement fusion (ICF). In the laser facility, fused silica optics plays irreplaceable role to conduct extremely high-intensity ultraviolet laser to fusion target. However, the surface fractures, such as surface pit, crack, scratch, and laser damage site, of the optics will lower the beam quality of transmitted laser, weaken the laser damage-resistance, shorten the lifetime of the optics, and thus limit the output performance of the laser facility. In this work, to mitigate the surface fractures, hydrofluoric acid-based (HF-based) etching effect on the surface fractures is experimentally and theoretically studied. From the experimental study, with the result of three-dimensional (3D) morphological evolution of surface fractures, it is shown that the surface fractures will be passivated and their profiles will get smoothed after etching, indicating HF-based etching is a promising way to improve the local surface quality of the fractures. Especially, it is found HF-based etching can greatly suppress the laser damage growth of laser damage site by mitigating its surface and subsurface fractures, and thus is a promising wet chemical method for repairing laser-induced damage optics. In the theoretical study, an explicit local-curvature dependent etching model is proposed. Based on this model, the result from finite difference time domain (FDTD) simulation agrees very well with that of experiment, which can reveal the detailed physical process of HF-based etching. It is demonstrated that the FDTD simulation can be a reliable and efficient way to predict the morphological evolution of the surface fractures during etching.
分类： 化学 >> 无机化学 提交时间： 2018-10-04
Chao, Zhao
Can, Xiong
Man, Qiao
Tongwei, Yuan
Jing, Wang
Yunteng, Qu
XiaoQian, Wang
Fangyao, Zhou
Zhijun, Li
Qian, Xu
Shiqi, Wang
Min, Chen
Wenyu, Wang
Yafei, Li
Yuen, Wu
Yadong, Li
摘要： 在这里，我们报告了一种高温气体迁移策略来制备多相的单原子铁催化剂，并展示其优良的类天然酶的活性（定义为单原子酶，SAE）。 结果表明，Fe SAE的局部定义明确的FeN4位点与含血红素的天然酶的活性金属中心高度相似。 Fe SAE表现出超级高的类过氧化物酶，氧化酶和过氧化氢酶的活性，超过了Fe3O4纳米酶40倍。更重要的是，Fe SAE可以有效活化过氧化氢（H2O2）产生羟基自由基（•OH）。 这使得其可以作为一种多相化的类Fenton系统，可以应对不断增加的环境污染。 我们的研究结果开辟了一个新的人造材料家族-模仿天然
分类： 物理学 >> 原子与分子物理学 分类： 化学 >> 化学物理学 提交时间： 2018-05-19
摘要： 见英文摘要
分类： 化学 >> 物理化学 提交时间： 2017-11-05 合作期刊: 《结构化学》
摘要： In order to enhance water-solubility and biological utilization rate of tectochrysin, sodium 5-hydroxyl-7-methoxyflavone-6-sulfonate (1) was synthesized and its structure was identified on the basis of 1H NMR, FT-IR and elemental analysis. 5-Hydroxyl-7-methoxyflavone-6-sulfonate was assembled with Ni(II) or Mn(II), hexaquanickel(II) bis(5-hydroxyl-7-methoxyflavone-6-sulfonate) tetrahydrate (2) and hexaquamanganese(II) bis(5-hydroxyl-7-methoxyflavone-6-sulfonate) tetrahydrate (3) were obtained and characterized by IR spectroscopy. The crystal structures of 2 and 3 were determined by X-ray single-crystal diffraction analysis. The results showed that 2 and 3 are isomorphous crystals and crystallize in monoclinic crystal system, space group C2/c. In 2 and 3, the supramolecular structures are organized into hydrophilic and hydrophobic regions. Hydrophilic regions are generated by O–H×××O hydrogen bonds among sulfonate groups, latticed water molecules and coordinated water molecules. The π-π stacking interactions assemble the flavone skeletons into columns and these columns form hydrophobic regions. The sulfonate groups play an important role as a bridge of the hydrophilic and hydrophobic regions as well as the inorganic and organic components. Three-dimensional networks of 2 and 3 are furnished by extensive array of hydrogen bonds, π-π stacking interactions and electrostatic interactions. The anti-proliferative activities of 1～3 in vitro against human leukemia cells K562 and human lung cancer cells A549 were evaluated by the standard MTT assay. The pharmacological activity results showed that the introduction of sulfonic acid groups enhanced the antitumor activity of tectochrysin.
分类： 化学 >> 物理化学 提交时间： 2017-11-05 合作期刊: 《结构化学》
摘要： Fortunella margarita (Lour.) Swingle, commonly known as kumquat, is the smallest citrus fruit. It thrives in southeastern China and is widely cultivated and consumed in the world due to its multiple health benefits. It has been used as an important herbal medicine in traditional Chinese medicine and also as one of the most popular fruits. There are various kinds of bioactive compounds in F. margarita, such as polysaccharides, limonoids, essential oils, flavonoids, phenolic acids, vitamins, dietary fiber, etc. In addition, many studies have reported that these bioactive compounds can be used as antioxidant, antimicrobial, hypolipidemic, drosophila lure components in functional foods, pharmaceuticals and daily chemical products due to their biological activities. This review focuses on the structural features and biological activities of polysaccharides, limonoids, essential oils and flavonoids and other bioactive substances from F. margarita and their potential applications in food, daily chemical and pharmaceutical industries.
分类： 化学 >> 物理化学 提交时间： 2017-11-05 合作期刊: 《结构化学》
摘要： Two new coordination polymers, namely, {[Cd1.5(bc)2(HL)].H2O}2n (1) and [Mn(ip)(H2L)(H2O)]n (2) (H2L = 3-(1H-pyrazol-4-yl)-5-(pyridin-2-yl)-1,2,4-triazole, Hbc = benzoic acid, H2ip = isophthalic acid) were constructed by solvothermal reaction. The compounds were characterized by elemental analysis, FT-IR spectroscopy, and single-crystal X-ray diffraction. Compound 1 displays a two-dimensional plane structure consisting of [Cd3(bc)2(HL)] subunits. Compound 2 possesses a one-dimensional chain structure and is further extended into a 3-D supramolecular architecture via hydrogen bonds. Moreover, photoluminescence studies showed compound 1 exhibits luminescent emissions with emission maxima at 375 nm. Magnetic susceptibility measurements of 2 indicate that domain antiferromagnetic interactions exist between Mn(II) ions. In addition, thermogravimetric properties of 1 and 2 were also measured.
分类： 化学 >> 物理化学 提交时间： 2017-11-05 合作期刊: 《结构化学》
摘要： Two new complexes [Ag(bix)]n·nNAA·nH2O (1) and [Cd(NAA)(phen)2(H2O)]2·2CH3COO-·H2O (2) (bix = 1,4-bis(imidazol-1-ylmethyl)benzene, HNAA = α-naphthylacetic acid, phen = 1,10-phenanthroline) have been successfully synthesized under hydrothermal conditions. Their structures have been determined by elemental analyses, IR spectroscopy, TG and single-crystal X-ray diffraction analysis. The intermolecular hydrogen bonding or π-π stacking interactions extend the complexes into a 3D supramolecular structure. Moreover, the luminescent properties of complex 2 have been investigated in the solid state.
分类： 化学 >> 物理化学 提交时间： 2017-11-05 合作期刊: 《结构化学》
摘要： A new complex [Cd2(L)2(Cl)2(H2O)]n (1) was synthesized by reacting CdCl2·2.5H2O with 4-(1,2,4-triazol-4-yl)phenylacetic acid (HL) ligand. The structure of the complex was characterized by single-crystal X-ray diffraction, IR spectroscopy, elemental analysis and PXRD. Complex 1 crystallizes in triclinic, space group P21/c with a = 11.4303(8), b = 14.1792(10), c = 14.6857(10) Å, β = 96.3780(10)º, V = 2365.4(3) Å3, Z = 4, C20H16Cl2N6O5Cd2, Mr = 716.09, Dc = 2.011 g/cm3, μ = 2.069-1, S = 1.051, F(000) = 1392, the final R = 0.0458 and wR = 0.0949 for 5402 observed reflections (I > 2σ(I)). Complex 1 is a two-dimensional (2D) layer structure and non-covalent bonding interactions such as C–H···π and π···π extend the 2D to form a three-dimensional supramolecular polymer.
分类： 化学 >> 物理化学 提交时间： 2017-11-05 合作期刊: 《结构化学》
摘要： Using a rigid azo ligand 4-[(8-hydroxy-5-quinolinyl)azo]-benzoic acid (H2L), a new supramolecular compound [Zn(L)(H2O)2]n (1) has been solvothermally synthesized and structurally characterized by X-ray single-crystal diffraction, infrared spectrum, elemental analysis, power X-ray diffraction and thermal analysis. Compound 1 crystallizes in monoclinic, space group C2/c with a = 30.372(8), b = 11.415(3), c = 9.248(3) Å, β = 106.94(3)º, V = 3067.20(15) Å3, C16H13N3O5Zn, Mr = 392.66, Z = 8, Dc = 1.701 Mg/m3; F(000) = 1600, μ = 1.636 mm−1, reflections collected: 7290, reflections unique: 2735, Rint = 0.0282, R = 0.0351, wR (all data) = 0.0919, GOOF on F2 = 1.036. Compound 1 exhibits a one-dimensional (1D) zig-zag chain structure connected into a three-dimensional (3D) supramolecular network through hydrogen bonding interactions. Fluorescent property and electrochemical property were detected on compound 1.
分类： 化学 >> 物理化学 提交时间： 2017-11-05 合作期刊: 《结构化学》
摘要： Er3+/Yb3+ co-doped Li3Ba2Gd3(MoO4)8 phosphors were synthesized by conventional solid state reaction method, and their structure and spectral properties were investigated. The diffuse reflectance spectra showed that the 4I15/2 → 4I11/2 transition of Er3+ and the 2F7/2 → 2F5/2 transition of Yb3+ ions were highly overlapped. Under the excitation of 980 nm, three up-conversion (UC) luminescence bands around 530, 555 and 660 nm were observed, corresponding to the 2H11/2 → 4I15/2, 4S3/2 → 4I15/2 and 4F9/2 → 4I15/2 transitions of Er3+ ions, respectively. The effects of the concentration and pumping power on the UC intensities of Li3Ba2Gd3(MoO4)8:Er3+/Yb3+ phosphors were investigated, and the possible UC mechanism was proposed based on the results.
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