Pub Date : 2026-02-10DOI: 10.1016/j.radphyschem.2026.113702
Fereshte Saheli, Luka Pasariček, Marija Majer
Due to its close relationship with Relative Biological Effectiveness (RBE), accurate determination of average Linear Energy Transfer (LET) distribution is of high importance in radiation therapy.
{"title":"Multi-Parameter Comparison of LET Distribution Calculations in Proton Beams Using Geant4 and PHITS","authors":"Fereshte Saheli, Luka Pasariček, Marija Majer","doi":"10.1016/j.radphyschem.2026.113702","DOIUrl":"https://doi.org/10.1016/j.radphyschem.2026.113702","url":null,"abstract":"Due to its close relationship with Relative Biological Effectiveness (RBE), accurate determination of average Linear Energy Transfer (LET) distribution is of high importance in radiation therapy.","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"5 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146146242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-10DOI: 10.1016/j.radphyschem.2026.113696
Arícia Ravane Pereira da Cruz, Lucas Delbem Albino, Ernesto Roesler, Claudio C. B. Viegas, Gabriel Henrique Rocha Barreto de França, Josemary Angélica Corrêa Gonçalves, Carmen Cecília Bueno, Vinícius Saito Monteiro de Barros, Viviane Khoury Asfora
In radiotherapy practice, external dosimetry audits represent a valuable tool for identifying systematic errors, improving the quality and safety of treatments, and ensuring consistency in clinical dosimetry procedures. Despite their proven importance, many radiotherapy centers are still unable to access these audits, especially in resource-constrained settings. With this in mind, the present study aimed to validate an independent postal dosimetry audit service for photon radiotherapy, currently being developed at the Department of Nuclear Energy of Federal University of Pernambuco (DEN/UFPE), using alanine-EPR dosimeters. The proposed system features a structure designed to support six dosimeter holders simultaneously, allowing the evaluation of central-axis and off-axis dose, as well as quality index, flatness and symmetry of photon beams generated by linear accelerators. The system’s performance was assessed by comparing measurements from the DEN/UFPE QA setup with results from the TLD-based dosimetry audit program of the Brazilian National Cancer Institute (PQRT/INCA) and with reference data obtained using a PTW 30013 ionization chamber under identical irradiation conditions. The interlaboratory comparison results demonstrated agreement among the systems, with dose deviations relative to the ionization chamber not exceeding 2.0% for the DEN/UFPE system and 1.9% for the PQRT/INCA system. Therefore, these findings provide robust evidence supporting the reliability, accuracy, and overall effectiveness of the proposed alanine-based postal dosimetry audit system, confirming its suitability for clinical implementation.
{"title":"Validation of an alanine-based postal dosimetry audit system for radiotherapy quality assurance","authors":"Arícia Ravane Pereira da Cruz, Lucas Delbem Albino, Ernesto Roesler, Claudio C. B. Viegas, Gabriel Henrique Rocha Barreto de França, Josemary Angélica Corrêa Gonçalves, Carmen Cecília Bueno, Vinícius Saito Monteiro de Barros, Viviane Khoury Asfora","doi":"10.1016/j.radphyschem.2026.113696","DOIUrl":"https://doi.org/10.1016/j.radphyschem.2026.113696","url":null,"abstract":"In radiotherapy practice, external dosimetry audits represent a valuable tool for identifying systematic errors, improving the quality and safety of treatments, and ensuring consistency in clinical dosimetry procedures. Despite their proven importance, many radiotherapy centers are still unable to access these audits, especially in resource-constrained settings. With this in mind, the present study aimed to validate an independent postal dosimetry audit service for photon radiotherapy, currently being developed at the Department of Nuclear Energy of Federal University of Pernambuco (DEN/UFPE), using alanine-EPR dosimeters. The proposed system features a structure designed to support six dosimeter holders simultaneously, allowing the evaluation of central-axis and off-axis dose, as well as quality index, flatness and symmetry of photon beams generated by linear accelerators. The system’s performance was assessed by comparing measurements from the DEN/UFPE QA setup with results from the TLD-based dosimetry audit program of the Brazilian National Cancer Institute (PQRT/INCA) and with reference data obtained using a PTW 30013 ionization chamber under identical irradiation conditions. The interlaboratory comparison results demonstrated agreement among the systems, with dose deviations relative to the ionization chamber not exceeding 2.0% for the DEN/UFPE system and 1.9% for the PQRT/INCA system. Therefore, these findings provide robust evidence supporting the reliability, accuracy, and overall effectiveness of the proposed alanine-based postal dosimetry audit system, confirming its suitability for clinical implementation.","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"9 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146146247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-10DOI: 10.1021/acssuschemeng.5c12647
Hampus Johansson, Liam Mistry, Ahilan Manisekaran, Henrik Sarge, Anette Larsson, Li-Yang Liu, Merima Hasani, Hans Theliander
The LignoBoost process enables efficient isolation of high-purity lignin from black liquor; however, lignin colloidal behavior during the acidic washing step strongly influences the filtration performance, and the impacts of temperature remain insufficiently understood. In this study, Kraft lignin suspensions were thermally treated at 75 °C, 85 °C, and 95 °C to evaluate their effects on volumetric flow rate during filtration and on lignin physicochemical properties. Thermal treatment at 85 °C yields the optimal filtration efficiency, with the volumetric flow rate increasing by 11-fold (lignin A) and 19-fold (Lignin B) compared to the control group. Particle size analysis revealed clear lignin particle growth after heating treatment, which was accompanied by a decrease in smaller particles. Beyond physical noncovalent interactions, chemical contributions to particle growth were elucidated by analyzing radical concentration, molar mass, and structural features. Radical concentrations decreased significantly, accompanied by increased condensation and reduced ester linkages in the recovered lignin. The molar mass changed slightly. Despite these changes, the overall functional group content (methoxy, aliphatic hydroxyl groups, and aromatic hydroxyl groups) and glass transition temperature remained largely unchanged. This work elucidates the interactive effects of heating treatment on lignin structure and recovery performance, providing a mechanistic understanding to optimize kraft lignin separation and thereby promote its subsequent valorization.
{"title":"Heating Treatment as a Simple Approach to Improve Lignin Filtration Efficiency in the LignoBoost Process","authors":"Hampus Johansson, Liam Mistry, Ahilan Manisekaran, Henrik Sarge, Anette Larsson, Li-Yang Liu, Merima Hasani, Hans Theliander","doi":"10.1021/acssuschemeng.5c12647","DOIUrl":"https://doi.org/10.1021/acssuschemeng.5c12647","url":null,"abstract":"The LignoBoost process enables efficient isolation of high-purity lignin from black liquor; however, lignin colloidal behavior during the acidic washing step strongly influences the filtration performance, and the impacts of temperature remain insufficiently understood. In this study, Kraft lignin suspensions were thermally treated at 75 °C, 85 °C, and 95 °C to evaluate their effects on volumetric flow rate during filtration and on lignin physicochemical properties. Thermal treatment at 85 °C yields the optimal filtration efficiency, with the volumetric flow rate increasing by 11-fold (lignin A) and 19-fold (Lignin B) compared to the control group. Particle size analysis revealed clear lignin particle growth after heating treatment, which was accompanied by a decrease in smaller particles. Beyond physical noncovalent interactions, chemical contributions to particle growth were elucidated by analyzing radical concentration, molar mass, and structural features. Radical concentrations decreased significantly, accompanied by increased condensation and reduced ester linkages in the recovered lignin. The molar mass changed slightly. Despite these changes, the overall functional group content (methoxy, aliphatic hydroxyl groups, and aromatic hydroxyl groups) and glass transition temperature remained largely unchanged. This work elucidates the interactive effects of heating treatment on lignin structure and recovery performance, providing a mechanistic understanding to optimize kraft lignin separation and thereby promote its subsequent valorization.","PeriodicalId":25,"journal":{"name":"ACS Sustainable Chemistry & Engineering","volume":"38 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2026-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146146269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bin Wang, Beining Guo, Muhammad Mamoor, Yueyue Kong, Lu Wang, Fengbo Wang, Zhongxin Jing, Guangmeng Qu, Xiyu He, Lingtong Kong, Pengtu Zhang, Liqiang Xu
Lithium–sulfur batteries, despite their high specific capacity, high theoretical energy density, environmental benignity, and low cost-related unique advantages, face critical challenges including polysulfide shuttling, sluggish redox kinetics, and uncontrolled lithium dendrite growth. Here, we propose a magnetic field cooperative regulation strategy that concurrently optimizes both sulfur cathode and lithium via spin engineering and magnetohydrodynamic (MHD) effects. Bilayer-hollow FeNi boride bipyramids (FeNi─B) with nanoreactor architectures were designed, in which an external magnetic field triggers 3d-orbital electron spin rearrangement. Simultaneously, the uniform distribution of ions and dendrite-free deposition were achieved by driving lithium-ion spiral convection through MHD effects. It is worth noting that the optimized cells exhibit exceptional cycling stability under extreme conditions (−40°C). Density functional theory and multiphysics simulations jointly reveal two mechanisms: Spin-polarization-enhanced adsorption energy for sulfur species and lithium protection via Lorentz-force-mediated ion transport. This work establishes a novel paradigm for designing magnetic field-responsive electrocatalysts and manipulating spin-orbit coupling, offering broad implications for multiphysical-field strategies in next-generation batteries.
{"title":"Constructing Wide-Temperature-Range Li–S Batteries Through Synergistic Boride Spin-Polarization Coupling Regulation and Magnetohydrodynamic Effects","authors":"Bin Wang, Beining Guo, Muhammad Mamoor, Yueyue Kong, Lu Wang, Fengbo Wang, Zhongxin Jing, Guangmeng Qu, Xiyu He, Lingtong Kong, Pengtu Zhang, Liqiang Xu","doi":"10.1002/anie.202519187","DOIUrl":"https://doi.org/10.1002/anie.202519187","url":null,"abstract":"Lithium–sulfur batteries, despite their high specific capacity, high theoretical energy density, environmental benignity, and low cost-related unique advantages, face critical challenges including polysulfide shuttling, sluggish redox kinetics, and uncontrolled lithium dendrite growth. Here, we propose a magnetic field cooperative regulation strategy that concurrently optimizes both sulfur cathode and lithium via spin engineering and magnetohydrodynamic (MHD) effects. Bilayer-hollow FeNi boride bipyramids (FeNi─B) with nanoreactor architectures were designed, in which an external magnetic field triggers 3d-orbital electron spin rearrangement. Simultaneously, the uniform distribution of ions and dendrite-free deposition were achieved by driving lithium-ion spiral convection through MHD effects. It is worth noting that the optimized cells exhibit exceptional cycling stability under extreme conditions (−40°C). Density functional theory and multiphysics simulations jointly reveal two mechanisms: Spin-polarization-enhanced adsorption energy for sulfur species and lithium protection via Lorentz-force-mediated ion transport. This work establishes a novel paradigm for designing magnetic field-responsive electrocatalysts and manipulating spin-orbit coupling, offering broad implications for multiphysical-field strategies in next-generation batteries.","PeriodicalId":125,"journal":{"name":"Angewandte Chemie International Edition","volume":"315 1","pages":""},"PeriodicalIF":16.6,"publicationDate":"2026-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146146381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-10DOI: 10.1021/acs.inorgchem.6c00114
Jiao-Jing Jing, Yu-Xuan Lei, Lin Zhang, Li-Chuan Hu, Xiu-Yuan Li, Lei Hou, Yao-Yu Wang
The separation of C2 hydrocarbons is crucial yet energy-intensive in the petrochemical industry. This work reports a novel metal–organic framework (MOF), [Zn2(BDPO)0.5(5-atz)3]·2.5DMA·2H2O (1) (H4BDPO = N,N′-bis(3,5-dicarboxyphenyl)oxalamide, 5-Hatz = 5-amino-1H-tetrazole), constructed from mixed carboxylate and azolate linker with rich N/O active sites from oxalamide and amine groups in ligands, for efficient one-step purification of C2H4 from C2 hydrocarbons. The MOF has the characteristic of a unique layer–pillar framework based on the metal–azolate layers pillared by BDPO linkers and possesses candy-like cages with polar porous surfaces, leading to the adsorption selectivity, higher uptake, and affinity for C2H2 and C2H6 over C2H4. The MOF reveals significant IAST selectivities for C2H2/C2H4 (3.1) and C2H6/C2H4 (1.8) from equimolar mixtures at 298 K, and efficient one-step dynamic separation from C2H4/C2H6/C2H2 (8:1:1, v/v/v) ternary mixtures to produce high-purity C2H4 (99.9%). Grand canonical Monte Carlo (GCMC) simulations show that the strong host–guest interactions for C2H2 and C2H6 within the cages from the rich N/O active sites contribute to the excellent C2H4 separation ability.
{"title":"One MOF with a New Type of Layer–Pillar Structure and Candy-like Cages for One-Step Purification of C2H4 from C2 Hydrocarbons","authors":"Jiao-Jing Jing, Yu-Xuan Lei, Lin Zhang, Li-Chuan Hu, Xiu-Yuan Li, Lei Hou, Yao-Yu Wang","doi":"10.1021/acs.inorgchem.6c00114","DOIUrl":"https://doi.org/10.1021/acs.inorgchem.6c00114","url":null,"abstract":"The separation of C<sub>2</sub> hydrocarbons is crucial yet energy-intensive in the petrochemical industry. This work reports a novel metal–organic framework (MOF), [Zn<sub>2</sub>(BDPO)<sub>0.5</sub>(5-atz)<sub>3</sub>]·2.5DMA·2H<sub>2</sub>O (<b>1</b>) (H<sub>4</sub>BDPO = <i>N</i>,<i>N</i>′-bis(3,5-dicarboxyphenyl)oxalamide, 5-Hatz = 5-amino-1<i>H</i>-tetrazole), constructed from mixed carboxylate and azolate linker with rich N/O active sites from oxalamide and amine groups in ligands, for efficient one-step purification of C<sub>2</sub>H<sub>4</sub> from C<sub>2</sub> hydrocarbons. The MOF has the characteristic of a unique layer–pillar framework based on the metal–azolate layers pillared by BDPO linkers and possesses candy-like cages with polar porous surfaces, leading to the adsorption selectivity, higher uptake, and affinity for C<sub>2</sub>H<sub>2</sub> and C<sub>2</sub>H<sub>6</sub> over C<sub>2</sub>H<sub>4</sub>. The MOF reveals significant IAST selectivities for C<sub>2</sub>H<sub>2</sub>/C<sub>2</sub>H<sub>4</sub> (3.1) and C<sub>2</sub>H<sub>6</sub>/C<sub>2</sub>H<sub>4</sub> (1.8) from equimolar mixtures at 298 K, and efficient one-step dynamic separation from C<sub>2</sub>H<sub>4</sub>/C<sub>2</sub>H<sub>6</sub>/C<sub>2</sub>H<sub>2</sub> (8:1:1, v/v/v) ternary mixtures to produce high-purity C<sub>2</sub>H<sub>4</sub> (99.9%). Grand canonical Monte Carlo (GCMC) simulations show that the strong host–guest interactions for C<sub>2</sub>H<sub>2</sub> and C<sub>2</sub>H<sub>6</sub> within the cages from the rich N/O active sites contribute to the excellent C<sub>2</sub>H<sub>4</sub> separation ability.","PeriodicalId":40,"journal":{"name":"Inorganic Chemistry","volume":"1 1","pages":""},"PeriodicalIF":4.6,"publicationDate":"2026-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146146444","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jakob Steidel, Ina Michalsky, Milan Kivala, Petra Tegeder
N-heterotriangulenes (N-HTAs) are promising organic semiconductors for applications in eld eect transistors and solar cells. Thereby the electronic structure of organic/metal interfaces and thin lms is essential for the performance of organic-molecule-based devices. Here, we studied the electronic properties of two dierent N-HTAs, the N-HTA-550 and N-HTA-557, the latter containing an additional 7-membered ring, adsorbed on Au(111) using two-photon photoemission spectroscopy. We quantitatively determined the energetic positions of several occupied and unoccupied molecular (transport levels) and excitonic states (optical gap) in detail. The additional -C=C-bridge forming the 7-membered ring in N-HTA-557 resulted in a pronounced increase in the electron anity by 0.92 eV from 2.19 eV in N-HTA-550/Au(111) to 3.11 eV in N-HTA-557/Au(111) due to the increase of the π-conjugated electron system, while the rst ionization potential is nearly unaected. Structural variation or substitution pattern in N-HTAs foster the opportunity for tailoring their electronic properties.
n -异三角烯（N-HTAs）是在场效应晶体管和太阳能电池中应用前景广阔的有机半导体材料。因此，有机/金属界面和薄薄膜的电子结构对基于有机分子的器件的性能至关重要。本文利用双光子光谱学研究了两种不同的n - hta， N-HTA-550和N-HTA-557吸附在Au（111）上的电子性质，后者含有一个额外的7元环。我们定量地确定了几个占据和未占据分子的能量位置（输运水平）和激子状态（光隙）。N-HTA-557中额外的-C= c桥形成7元环，由于π共轭电子系统的增加，导致N-HTA-550/Au（111）中的电子度从2.19 eV显著增加到3.11 eV，增加了0.92 eV，而剩余电离势几乎未受影响。N-HTAs的结构变化或取代模式为调整其电子性质提供了机会。
{"title":"Quantitative electronic structure determination of N-heterotriangulene derivatives adsorbed on Au(111)","authors":"Jakob Steidel, Ina Michalsky, Milan Kivala, Petra Tegeder","doi":"10.1039/d5cp04526f","DOIUrl":"https://doi.org/10.1039/d5cp04526f","url":null,"abstract":"N-heterotriangulenes (N-HTAs) are promising organic semiconductors for applications in eld eect transistors and solar cells. Thereby the electronic structure of organic/metal interfaces and thin lms is essential for the performance of organic-molecule-based devices. Here, we studied the electronic properties of two dierent N-HTAs, the N-HTA-550 and N-HTA-557, the latter containing an additional 7-membered ring, adsorbed on Au(111) using two-photon photoemission spectroscopy. We quantitatively determined the energetic positions of several occupied and unoccupied molecular (transport levels) and excitonic states (optical gap) in detail. The additional -C=C-bridge forming the 7-membered ring in N-HTA-557 resulted in a pronounced increase in the electron anity by 0.92 eV from 2.19 eV in N-HTA-550/Au(111) to 3.11 eV in N-HTA-557/Au(111) due to the increase of the π-conjugated electron system, while the rst ionization potential is nearly unaected. Structural variation or substitution pattern in N-HTAs foster the opportunity for tailoring their electronic properties.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"46 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146146523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-10DOI: 10.1016/j.radphyschem.2026.113700
S.A. Mahdipour, M. Shafeei Sarvestani, S.B. Dabagov, A.A. Mowlavi
Radiation Pressure Acceleration (RPA) and Target Normal Sheath Acceleration (TNSA) are the two most significant methods for designing Laser-Accelerated Proton Beam (LAP) systems. LAP technology has inspired innovative applications that leverage the unique properties of proton bunches, distinguishing them from conventionally accelerated proton beams. In previous simulations, we presented a fundamental model of the proton beamline based on two pulsed-power solenoids, utilizing Monte Carlo simulations with the GEANT4 toolkit. We conducted adjustments to the magnetic field of the first solenoid and precisely calculated the flux of primary protons and secondary radiations in the beamline. This article introduces the second solenoid, providing detailed specifications and incorporating it into the previous simulations, optimizing its magnetic field. Additionally, the absorbed dose from RPA protons in a water phantom has been calculated. The simulation results demonstrated that incorporating and optimizing the second solenoid within the beamline significantly enhanced proton beam energy selection and shaping. This optimization effectively filtered out lower-energy protons, reduced the effective energy spread, and consequently shifted the maximum dose deposition to a greater depth within the water phantom. Furthermore, as the incident energy dispersion decreased, the dose profile became more concentrated, and the width of the high-dose region was reduced. Analysis of secondary neutron and photon doses also revealed that controlling the incident proton energy spectrum has a pronounced effect on reducing secondary photon doses. The calculations presented in this paper constitute a preliminary step toward completing the full RPA beamline simulation model.
{"title":"Proton absorbed dose from laser-accelerated proton beamline (LAP) based on RPA method","authors":"S.A. Mahdipour, M. Shafeei Sarvestani, S.B. Dabagov, A.A. Mowlavi","doi":"10.1016/j.radphyschem.2026.113700","DOIUrl":"https://doi.org/10.1016/j.radphyschem.2026.113700","url":null,"abstract":"Radiation Pressure Acceleration (RPA) and Target Normal Sheath Acceleration (TNSA) are the two most significant methods for designing Laser-Accelerated Proton Beam (LAP) systems. LAP technology has inspired innovative applications that leverage the unique properties of proton bunches, distinguishing them from conventionally accelerated proton beams. In previous simulations, we presented a fundamental model of the proton beamline based on two pulsed-power solenoids, utilizing Monte Carlo simulations with the GEANT4 toolkit. We conducted adjustments to the magnetic field of the first solenoid and precisely calculated the flux of primary protons and secondary radiations in the beamline. This article introduces the second solenoid, providing detailed specifications and incorporating it into the previous simulations, optimizing its magnetic field. Additionally, the absorbed dose from RPA protons in a water phantom has been calculated. The simulation results demonstrated that incorporating and optimizing the second solenoid within the beamline significantly enhanced proton beam energy selection and shaping. This optimization effectively filtered out lower-energy protons, reduced the effective energy spread, and consequently shifted the maximum dose deposition to a greater depth within the water phantom. Furthermore, as the incident energy dispersion decreased, the dose profile became more concentrated, and the width of the high-dose region was reduced. Analysis of secondary neutron and photon doses also revealed that controlling the incident proton energy spectrum has a pronounced effect on reducing secondary photon doses. The calculations presented in this paper constitute a preliminary step toward completing the full RPA beamline simulation model.","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"46 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146146418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dietrich Haase, Jörn Manz, Beate Paulus, Jonathan Scherlitzki, Jean Christophe Tremblay
Electronic chirality flips in achiral molecules is a hot topic in attosecond and femtosecond chemistry and physics. Our quantum dynamics simulations show that this effect can be induced by a simple Franck–Condon excitation of the A′ + A″ superposition of the electronic A′ ground state plus the first excited A″ state in the oriented bent triatomic heteronuclear molecule NSF.
{"title":"A simple approach to attosecond electronic chirality flips using triatomic molecules","authors":"Dietrich Haase, Jörn Manz, Beate Paulus, Jonathan Scherlitzki, Jean Christophe Tremblay","doi":"10.1039/d5cp04637h","DOIUrl":"https://doi.org/10.1039/d5cp04637h","url":null,"abstract":"Electronic chirality flips in achiral molecules is a hot topic in attosecond and femtosecond chemistry and physics. Our quantum dynamics simulations show that this effect can be induced by a simple Franck–Condon excitation of the <em>A</em>′ + <em>A</em>″ superposition of the electronic <em>A</em>′ ground state plus the first excited <em>A</em>″ state in the oriented bent triatomic heteronuclear molecule NSF.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"12 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146146487","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The structural stability and lithium-storage properties of Snx and SnxCoy (x + y ≤ 7) clusters intercalated between bilayer graphene were systematically investigated via first-principles calculations based on DFT. In the Snx/BLG systems, the Sn4 cluster was found to exhibit superior structural stability through the combined analysis of formation energy and second-order difference energy. The Sn–C bond length in Snx clusters increased from 2.54 Å to 2.85 Å, accompanied by a marked intensification of carbon-layer distortion. Upon the introduction of Co atoms, among the SnxCoy clusters, SnCo and Sn4Co clusters were observed to exhibit the lowest formation energies and highest structural stability, thereby effectively mitigating atomic distortion of the bilayer graphene (BLG) carbon layers. The second-order difference energy (Δ2E) provides an effective criterion for evaluating the structural stability of intercalated clusters, enabling the screening of energetically stable Snx and SnxCoy cluster models. Lithium-storage calculations for SnCo and Sn4Co cluster intercalated BLG systems demonstrate that Li atoms are preferentially adsorbed around SnxCoy clusters and transfer charge to graphene layers. With increasing Li content, per-Li charge transfer decreases and inter-Li repulsion strengthens, reducing stability at high Li concentrations. Furthermore, Co doping strengthens the electronic coupling between the clusters and the graphene layers. In the Sn4Co/BLG system, Li insertion not only reduces the degree of localization of the density of states near the Fermi level but also enhances the conductivity of the system.
{"title":"Growth behavior and lithium storage performance of SnxCoy (x + y ≤ 7) clusters in double-layer graphene based on first-principles calculations","authors":"Ding Shen, YongHui Ma, YouZhi Yang, YingKai Xia, ZhaoQi Ren, Nuo Li, LiXin Mi, Wei Dong, ShuWei Tang","doi":"10.1039/d5cp03874j","DOIUrl":"https://doi.org/10.1039/d5cp03874j","url":null,"abstract":"The structural stability and lithium-storage properties of Sn<small><sub><em>x</em></sub></small> and Sn<small><sub><em>x</em></sub></small>Co<small><sub><em>y</em></sub></small> (<em>x</em> + <em>y</em> ≤ 7) clusters intercalated between bilayer graphene were systematically investigated <em>via</em> first-principles calculations based on DFT. In the Sn<small><sub><em>x</em></sub></small>/BLG systems, the Sn<small><sub>4</sub></small> cluster was found to exhibit superior structural stability through the combined analysis of formation energy and second-order difference energy. The Sn–C bond length in Sn<small><sub><em>x</em></sub></small> clusters increased from 2.54 Å to 2.85 Å, accompanied by a marked intensification of carbon-layer distortion. Upon the introduction of Co atoms, among the Sn<small><sub><em>x</em></sub></small>Co<small><sub><em>y</em></sub></small> clusters, SnCo and Sn<small><sub>4</sub></small>Co clusters were observed to exhibit the lowest formation energies and highest structural stability, thereby effectively mitigating atomic distortion of the bilayer graphene (BLG) carbon layers. The second-order difference energy (Δ<small><sup>2</sup></small><em>E</em>) provides an effective criterion for evaluating the structural stability of intercalated clusters, enabling the screening of energetically stable Sn<small><sub><em>x</em></sub></small> and Sn<small><sub><em>x</em></sub></small>Co<small><sub><em>y</em></sub></small> cluster models. Lithium-storage calculations for SnCo and Sn<small><sub>4</sub></small>Co cluster intercalated BLG systems demonstrate that Li atoms are preferentially adsorbed around Sn<small><sub><em>x</em></sub></small>Co<small><sub><em>y</em></sub></small> clusters and transfer charge to graphene layers. With increasing Li content, per-Li charge transfer decreases and inter-Li repulsion strengthens, reducing stability at high Li concentrations. Furthermore, Co doping strengthens the electronic coupling between the clusters and the graphene layers. In the Sn<small><sub>4</sub></small>Co/BLG system, Li insertion not only reduces the degree of localization of the density of states near the Fermi level but also enhances the conductivity of the system.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"41 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146146518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bruna B. Segat, Adolfo Horn, Bruno Szpoganicz, Lino Meurer, Roberta Cargnelutti, Rodrigo Cervo, Luis Gabriel Wagner, Sreerag N. Moorkkannur, Rajeev Prabhakar, Lucas C. Pinheiro, Siti Noriza Kamel, Sumeet Mahajan, Martin Feelisch, Christiane Fernandes
Overproduction of nitric oxide (˙NO) with subsequent formation of peroxynitrite has a major impact on cell death, inflammation, and disease development. ˙NO exerts a significant part of its biological activity through S-nitrosylation, leading to the formation of protein and low-molecular-weight nitrosothiols such as S-nitrosoglutathione (GSNO). Excessive oxidative/nitrosative stress contributes to disease by S-nitrosylating multiple targets, culminating in the accumulation of misfolded proteins and cytotoxicity. We here report on the discovery that a water-soluble copper(II) compound [Cu(HL)Cl2] (1) (HL = N-2[(pyridine-2-ylmethyl)aminoethanol]) promotes homolytic cleavage of the S–NO bond to form ˙NO and glutathione disulfide (GSSG), following initial coordination of the sulfur atom of GSNO to the Cu(II) center. The X-ray crystal structure of complex 1 is presented. Potentiometric titration studies indicate that the species [Cu(HL)(H2O)2]2+ is the major species at physiological pH (Kf = 9.33 × 106). Monitoring the reaction between 1 and GSNO by EPR spectroscopy revealed that the Cu(II) signal remains stable throughout the reaction. The release of ˙NO was confirmed using the spin trap [Fe(DETC)2], while formation of the GS˙ intermediate was detected using DMPO. EPR analysis also confirmed the formation of a Cu–S bond, as evidenced by superhyperfine coupling, further corroborated by Raman spectroscopy and UV–Vis studies. The latter indicates that two equivalents of GSNO coordinate to the copper centers, in agreement with the kinetic studies. The formation of several intermediate species and production of GSSG was confirmed by ESI-(+)-MS. Gas-phase chemiluminescence experiments performed under both aerobic and anaerobic conditions showed that the amounts of ˙NO produced are independent of the presence of oxygen. Taken together, our experimental data suggest that, during GS–NO bond cleavage, the Cu(II) center does not undergo reduction, allowing the proposal of a novel reaction mechanism, the feasibility of which is supported by theoretical calculations. Thus, copper(II) complexes with tridentate ligands promote efficient denitrosylation without undergoing bulk electron transfer of the transition metal, potentially opening new avenues for modulating S-nitrosothiol stability in disease conditions known to be associated with excessive nitrosation.
{"title":"Mechanistic investigation of the denitrosylation activity of a water-soluble copper(II) compound probed by experimental and computational approaches","authors":"Bruna B. Segat, Adolfo Horn, Bruno Szpoganicz, Lino Meurer, Roberta Cargnelutti, Rodrigo Cervo, Luis Gabriel Wagner, Sreerag N. Moorkkannur, Rajeev Prabhakar, Lucas C. Pinheiro, Siti Noriza Kamel, Sumeet Mahajan, Martin Feelisch, Christiane Fernandes","doi":"10.1039/d5qi02129d","DOIUrl":"https://doi.org/10.1039/d5qi02129d","url":null,"abstract":"Overproduction of nitric oxide (˙NO) with subsequent formation of peroxynitrite has a major impact on cell death, inflammation, and disease development. ˙NO exerts a significant part of its biological activity through <em>S</em>-nitrosylation, leading to the formation of protein and low-molecular-weight nitrosothiols such as <em>S</em>-nitrosoglutathione (GSNO). Excessive oxidative/nitrosative stress contributes to disease by <em>S</em>-nitrosylating multiple targets, culminating in the accumulation of misfolded proteins and cytotoxicity. We here report on the discovery that a water-soluble copper(<small>II</small>) compound [Cu(HL)Cl<small><sub>2</sub></small>] (<strong>1</strong>) (HL = <em>N</em>-2[(pyridine-2-ylmethyl)aminoethanol]) promotes homolytic cleavage of the S–NO bond to form ˙NO and glutathione disulfide (GSSG), following initial coordination of the sulfur atom of GSNO to the Cu(<small>II</small>) center. The X-ray crystal structure of complex <strong>1</strong> is presented. Potentiometric titration studies indicate that the species [Cu(HL)(H<small><sub>2</sub></small>O)<small><sub>2</sub></small>]<small><sup>2+</sup></small> is the major species at physiological pH (<em>K</em><small><sub>f</sub></small> = 9.33 × 10<small><sup>6</sup></small>). Monitoring the reaction between <strong>1</strong> and GSNO by EPR spectroscopy revealed that the Cu(<small>II</small>) signal remains stable throughout the reaction. The release of ˙NO was confirmed using the spin trap [Fe(DETC)<small><sub>2</sub></small>], while formation of the GS˙ intermediate was detected using DMPO. EPR analysis also confirmed the formation of a Cu–S bond, as evidenced by superhyperfine coupling, further corroborated by Raman spectroscopy and UV–Vis studies. The latter indicates that two equivalents of GSNO coordinate to the copper centers, in agreement with the kinetic studies. The formation of several intermediate species and production of GSSG was confirmed by ESI-(+)-MS. Gas-phase chemiluminescence experiments performed under both aerobic and anaerobic conditions showed that the amounts of ˙NO produced are independent of the presence of oxygen. Taken together, our experimental data suggest that, during GS–NO bond cleavage, the Cu(<small>II</small>) center does not undergo reduction, allowing the proposal of a novel reaction mechanism, the feasibility of which is supported by theoretical calculations. Thus, copper(<small>II</small>) complexes with tridentate ligands promote efficient denitrosylation without undergoing bulk electron transfer of the transition metal, potentially opening new avenues for modulating <em>S</em>-nitrosothiol stability in disease conditions known to be associated with excessive nitrosation.","PeriodicalId":79,"journal":{"name":"Inorganic Chemistry Frontiers","volume":"39 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2026-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146146173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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