Subjects: Chemistry >> Nuclear Chemistry submitted time 2024-05-02
Abstract: Abstract Background:Human epidermal growth factor receptor 2 (HER2) is widely present in many malignant tumors.It is associated with poor prognosis. Particularly in breast cancer, however, there is heterogeneity in HER2 expression.Currently immunohistochemistry and fluorescence
are used for assessing HER2 status. However they have so much significant limitations.HER2 receptor imaging has significant advantages. It is a potential option for detecting HER2-positive lesions of Radiolabeled mimetic peptides.Purpose:To prepare a 18F labeled human epidermal growth factor receptor2(HER2) peptide B2-S22-AFA(18F-NFP-TP1296),and evaluate its biodistribution and microPET characteristics.Methods:The tracer conjugate was labeled with 18F in one step.18F-NFP-TP1296 was performed in vitro studies and MicroPET imaging in the SKBR-3 breast cancer model.Rusults:18F-NFP-TP1296 was synthesized in about 30 min with the non-decay corrected yields more than 10%, and radiochemical purity more than 95%.MicroPET imaging revealed that the SKBR-3 xenografts were visualized and the tumor uptakes were 5.63±0.14%ID/g、6.26±0.27%ID/g and 5.83±0.44%ID/g at 30min、60min and 120min.The corresponding tumor-to-blood and tumor-to-muscle ratios were 3.21±0.32、4.08±0.73 and 1.69±0.18 respectively, and 1.55±0.11%ID/g、1.84±0.12%ID/g and 3.10±0.30%ID/g at 30、60 and 120min. The lung metastasis tumor uptakes were 2.2%ID/g、2.5%ID/g and 2.1%ID/g at 30、60 and 120min.Conclusion:18F-NFP-TP1296 can be successfully labeled by one-step method.The 18F-NFP-TP1296 probe owns the advantages of favorable imaging properties, convenient preparation, excellent stability, safety, rapid clearance in the blood, which support its application for further research.
Subjects: Biology >> Biophysics Subjects: Chemistry >> Physical Chemistry Subjects: Biology >> Biophysics submitted time 2024-04-16
Abstract: 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-initio level 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 variations of 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.
Peer Review Status:Awaiting Review
Subjects: Chemistry >> Nuclear Chemistry submitted time 2024-04-09
Abstract: In the process of accelerated development of nuclear medicine department in recent years, the construction of decay tanks and the storage time of radioactive wastewater containing I-131 have become issues of great concern for environmental regulatory agencies and hospitals. Basic Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources (GB 18871), Radiation Protection and Safety Requirements for Nuclear Medicine (HJ 1188), and Reply to Consultation on Several Clauses of the Nuclear Medicine Standard have stipulated the compliant discharge methods for radioactive wastewater containing I-131 from hospitals. This paper presents a theoretical calculation formula for the total activity of iodine-131 when a delay tank in a hospital is full. It demonstrates that among the three compliant disperse methods for radioactive wastewater containing iodine-131 in the decay tank, the method specified in GB 18871 is advantageous for the operation of the nuclear medicine department in the hospital. The paper also introduces the RJ equation group, which addresses the calculation of minimum decay time and volume of the decay tank. The actual measured data from four hospitals demonstrates that when the temporary storage period for radioactive wastewater containing iodine-131 reaches the minimum time calculated by the RJ equations, the total discharge activity of iodine-131 complies with the national environmental protection standards.These findings provide clear and specific guidance for the construction of decay tanks in nuclear medicine departments and for the supervision and inspection conducted by regulatory authorities.
Subjects: Chemistry >> Applied Chemistry submitted time 2024-01-23
Abstract: Addressing the drawbacks of conventional formula design methods, such as being cumbersome, time-consuming, resulting in material wastage, and yielding poor optimization outcomes, a novel approach for optimizing the formula of aluminum alloy cleaners is proposed by combining the Latin Hypercube Design (LHD) algorithmwith the Multilayer Perceptron (MLP) neural network. Leveraging the comprehensive exploration of parameter space using the LHD algorithm and the efficient modeling capability of the MLP neural network, the formula for aluminum alloy cleaners was successfully optimized. With the optimized formula, the cleaning efficiency increased from 87.9% to 98.24%, and the corrosion rate decreased from 4.2 mg to 0.3 mg. Regression analysis of the model's predicted data against experimental data yielded a correlation coefficient greater than 0.98, demonstrating consistency between predicted and experimental data.
Peer Review Status:Awaiting Review
Subjects: Chemistry >> Chemical Physics submitted time 2023-12-09
Abstract: 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.
Peer Review Status:Awaiting Review
Subjects: Chemistry >> Nuclear Chemistry submitted time 2023-06-13
Abstract: 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 μg·L-1 (pH 4, 25℃). Results: The maximum adsorption capacity of the adsorbent material was 137.3 mg·g-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 4–10, with good selectivity and reusability, demonstrating its potential for seawater uranium extraction.
Subjects: Chemistry >> Nuclear Chemistry submitted time 2023-06-06
Abstract: 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 γ-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 γ-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 γ-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 γ-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.
Subjects: Chemistry >> Nuclear Chemistry submitted time 2023-05-31
Abstract: 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.
Subjects: Biology >> Biophysics Subjects: Materials Science >> Biomaterials Subjects: Chemistry >> Chemical Biology Subjects: Medicine, Pharmacy >> Preclinical Medicine submitted time 2023-02-09
Abstract:
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.
Peer Review Status:Awaiting Review
Subjects: Chemistry >> Applied Chemistry submitted time 2020-03-05
Abstract: [Objective] Synthesis of potential neroprotective agent catalpol perpropionylated derivative (CP-6), and determination of the optimal microwav-assisted synthesis conditions. [Methods] CP-6 was synthesized by microwave-assisted synthesis (MCAS) using catalpol and propionyl anhydride as raw materials and pyridine as solvent and acid-binding agent. It was characterized by FT-IR, HRMS, NMR and assayed for neuroprotective activity by MTT method. [Results] When the molar ratio of propionic anhydride to catalpol is 18, the concentration of catalol in pyridine is 25 g/L, the reaction temperature of microwave reactor is 80 ℃, and the reaction time is 6 h, the yield of CP-6 can reach 98.51%. CP-6 has potential neroprotective activity."
Peer Review Status:Awaiting Review
Subjects: Chemistry >> Chemical Physics submitted time 2018-11-28
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Peer Review Status:Awaiting Review
Subjects: Chemistry >> Inorganic Chemistry submitted time 2018-10-04
Abstract: Herein, we report a high-temperature gas-migration strategy to fabricate a heterogeneous single iron atom catalyst and demonstrate its excellent natural enzymes-like activity (defined as single atom enzymes, SAEs). The results reveal that the localized well-defined FeN4 sites of Fe SAEs is highly similar to the active metal centers of the natural heme-containing enzymes. The Fe SAEs exhibits superduper peroxidase, oxidase and catalase enzyme-like activities, exceeding that Fe3O4 nanozymes by a factor of 40. More importantly, Fe SAEs could effectively activates hydrogen peroxide (H2O2) in a hydroxyl free radicals (•OH) pathway, which makes it useful as a heterogeneous Fenton-like system to deal with the increasing environmental pollution. Our findings open up a new family of artificial material that mimics the natural enzymes.
Peer Review Status:Awaiting Review
Subjects: Physics >> Atomic and Molecular Physics Subjects: Chemistry >> Chemical Physics submitted time 2018-05-19
Abstract:
See the paper
Peer Review Status:Awaiting Review
Subjects: Chemistry >> Physical Chemistry submitted time 2017-11-05 Cooperative journals: 《结构化学》
Abstract: 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.
Subjects: Chemistry >> Physical Chemistry submitted time 2017-11-05 Cooperative journals: 《结构化学》
Abstract: 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.
Subjects: Chemistry >> Physical Chemistry submitted time 2017-11-05 Cooperative journals: 《结构化学》
Abstract: 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.
Subjects: Chemistry >> Physical Chemistry submitted time 2017-11-05 Cooperative journals: 《结构化学》
Abstract: 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.
Subjects: Chemistry >> Physical Chemistry submitted time 2017-11-05 Cooperative journals: 《结构化学》
Abstract: 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.
Subjects: Chemistry >> Physical Chemistry submitted time 2017-11-05 Cooperative journals: 《结构化学》
Abstract: 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.
Subjects: Chemistry >> Physical Chemistry submitted time 2017-11-05 Cooperative journals: 《结构化学》
Abstract: 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.