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Validation of the TOPAS Monte-Carlo Code of the Off-Field dose of a 6 MV Synergy Linac

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Journal of Biosciences and Medicines 2024年第7期12卷 38-54页

作者： Kodjo Joel Fabrice n’Guessan Ibrahima Sakho Bogbé d. L. H. Gogon department of Physics and Chemistry Faculty of Sciences and Technology Iba Der Thiam University of This This Senegal International Cancer Center of dakar Dakar Senegal department of Physics Faculty of Sciences and Technology Flix Houphouet Boigny University of Abidjan Abidjan Cte dIvoire

The risk of radiation-induced second cancer and the late tissue loss due to Off-field doses in radiotherapy remain a serious concern. Monte Carlo (MC) simulation is currently one of the most accurate methods for calculating these doses. MC simulation model based on the Particle Simulation Tool (TOPAS) has been developed to simulate the off-field dose of an Elekta Synergy linear accelerator (Linac) emitting 6 MV photons. Measurements were taken in a water phantom using an ionization chamber to validate this model. The Percentage depth dose (Pdd) at the depth of 0.0, 5.0, 10.0 and 15.0 cm from the beam axis for a 10 × 10 cm2 field size was measured and simulated. Off-field dose profiles at the depth of 1.5 (dmax), 5.0 and 10.0 cm for field sizes of 5 × 5, 10 × 10, 15 × 15, and 20 × 20 cm2 respectively were measured and simulated. Comparison of measured and simulated off-field dose values showed a good agreement. The average gamma passing rate of the Pdds and profiles curves for off-field doses were 87.5% and 98.11% respectively. The local dose difference based on the Pdd curve between the measured and simulated was less than 6.0 % for all locations. For all field size considered in this study, the average difference between profile curves for off-field dose measured and simulated was 9.1%. Pdds and Profiles curves for off-field dose simulation uncertainties were less than 2.0% and 1.0% respectively. TOPAS-MC simulation model developed is a good representation of our 6 MV Linac Elekta Synergy for assessing off-field dose, which would be the primary cause of some secondary cancers.

关键词： Radiotherapy Off-Field dose Secondary Cancer TOPAS-MC Simulation dosimetry

Are population cycles recovering?

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Integrative Zoology 2024年第3期19卷 538-547页

作者： Vasily d.YAKUSHOV Boris I.SHEFTEL A.n.Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences MoscowRussia

The dynamics of populations of small mammals of Central Siberia was *** studies were carried out at the Yenisei ecological station“Mirnoye”of the *** Institute of Ecology and Evolution,Russian Academy of *** time series analysis was performed by the wavelet transform using the statistical data processing language *** the 20th century,the dynamics of the population of the community and some of its constituent species(Sorex araneus;***;***;***;***;Craseomys rufocanus;Clethrionomys rutilus;Microtus oeconomus;***)were characterized by a 4-year *** type of dynamics changed to noncyclic by the nineties,but by 2022,four species(***,***,***,and ***)and the community as a whole showed a tendency toward recovery of population *** remaining species were characterized by consistently low numbers with irregular low amplitude fluctuations.

关键词： population cycles small mammals time-series analysis wavelet transform

Previously undiagnosed Morgagni hernia with bowel perforation detected during repeat screening colonoscopy: A case report

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World Journal of Clinical Cases 2024年第14期12卷 2389-2395页

作者： Said Al Alawi Alan n Barkun Sara najmeh division of Gastroenterology McGill UniversityMontrealQC H4A 3J1Canada division of Thoracic surgery McGill UniversityMontrealQC H4A 3J1Canada

BACKGROUnd Morgagni hernia(MH)is a form of congenital diaphragmatic hernia(CdH)characterized by an incomplete formation of diaphragm,resulting in the protru-sion of abdominal organs into the thoracic *** estimated incidence of CdH is between 1 in 2000 and 1 in 5000 live births,although the true incidence is *** typically presents in childhood and can be diagnosed either pre-natally or ***,it can also be asymptomatic and carry the risk of developing into a life-threatening condition in *** SUMMARY A 76-year-old female with no history of prior abdominal surgeries presented for an elective colonoscopy for polyp *** the procedure,when approaching the hepatic flexure,the scope could not be advanced further despite multiple *** patient experienced mild abdominal discomfort,leading to the abortion of the *** in the recovery area,she developed increa-sing abdominal pains and *** abdominal imaging revealed her-niation of the proximal transverse colon through a MH into the chest with evi-dence of *** patient underwent laparoscopic urgent colonic resection and primary hernia repair and was discharged uneventfully 2 d *** A MH is a rare condition in adults that can present as a life-threatening compli-cation of colonoscopy,even in patients with a history of uneventful *** case highlights the importance of considering congenital and internal hernias when faced with sudden and unexplained difficulties during *** there is a suspicion of MH,the endoscopist should halt the procedure and immediately obtain abdominal imaging to confirm the diagnosis.

关键词： Bowel perforation Colonoscopy Adverse event Congenital diaphragmatic

An Improved Coupled Level Set and Continuous Moment-of-Fluid Method for Simulating Multiphase Flows with Phase Change

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Communications on Applied Mathematics and Computation 2024年第2期6卷 1034-1069页

作者： Zhouteng Ye Cody Estebe Yang Liu Mehdi Vahab Zeyu Huang mark Sussman Alireza Moradikazerouni Kourosh Shoele Yongsheng Lian Mitsuhiro Ohta M.Yousuff Hussaini ZJUI Institute Zhejiang UniversityHaining 314400ZhejiangChina department of Mathematics Florida State UniversityTallahasseeUSA department of Mechanical Engineering Florida State UniversityTallahasseeUSA Mechanical and Aerospace Engineering Mathworks NatickMAUSA School of Aerospace Engineering Tsinghua UniversityBeijing 100084China department of Mechanical Engineering University of LouisvilleLouisvilleUSA department of Mechanical Science Tokushima UniversityTokushimaJapan

An improved algorithm for computing multiphase flows is presented in which the multimaterial Moment-of-Fluid(MOF)algorithm for multiphase flows,initially described by Li et al.(2015),is enhanced addressing existing MOF difficulties in computing solutions to problems in which surface tension forces are crucial for understanding salient flow *** Continuous MOF(CMOF)method is motivated in this *** CMOF reconstruction method inherently removes the"checkerboard instability"that persists when using the MOF method on surface tension driven multiphase(multimaterial)*** CMOF reconstruction algorithm is accelerated by coupling the CMOF method to the level set method and coupling the CMOF method to a decision tree machine learning(ML)*** flow examples are shown in the two-dimensional(2d),three-dimensional(3d)axisymmetric"RZ",and 3d coordinate *** include two material and three material multiphase flows:bubble formation,the impingement of a liquid jet on a gas bubble in a cryogenic fuel tank,freezing,and liquid lens dynamics.

关键词： Moment-of-Fluid(MOF) Surface tension Two phase flow Phase change deforming boundaries with change(s)in topology Two-dimensional(2d) Three-dimensional(3d)axisymmetric 3d

Multifunctional SnO_(2) Qds/MXene Heterostructures as Laminar Interlayers for Improved Polysulfide Conversion and Lithium Plating Behavior

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nano-Micro Letters 2024年第11期16卷 156-169页

作者： Shungui deng Weiwei Sun Jiawei Tang Mohammad Jafarpour Frank nüesch Jakob Heier Chuanfang Zhang College of Materials Science and Engineering Sichuan UniversityChengdu 610065People’s Republic of China Laboratory for Functional Polymers Swiss Federal Laboratories for Materials Science and Technology(EMPA)Überlandstrasse 1298600 DübendorfSwitzerland Institute of Materials Science and Engineering Ecole Polytechnique Fédérale de Lausanne(EPFL)Station 121015 LausanneSwitzerland Key Laboratory of Quantum Materials and devices of Ministry of Education School of PhysicsSoutheast UniversityNanjing 211189People’s Republic of China SEU‑FEI nano‑Pico Center Key Laboratory of MEMS of Ministry of EducationSoutheast UniversityNanjing 210096People’s Republic of China

Poor cycling stability in lithium–sulfur(Li–S)batteries necessitates advanced electrode/electrolyte design and innovative interlayer *** catalysis has emerged as a promising approach,leveraging the adsorption and catalytic performance on lithium polysulfides(LiPSs)to inhibit LiPSs shuttling and improve redox *** this study,we report an ultrathin and laminar SnO_(2)@MXene heterostructure interlayer(SnO_(2)@MX),where SnO_(2) quantum dots(Qds)are uniformly distributed across the MXene *** combined structure of SnO_(2) Qds and MXene,along with the creation of numerous active boundary sites with coordination electron environments,plays a critical role in manipulating the catalytic kinetics of sulfur *** Li–S cell with the SnO_(2)@MX-modified separator not only demonstrates superior electrochemical performance compared to cells with a bare separator but also induces homogeneous Li deposition during *** a result,an areal capacity of 7.6 mAh cm^(-2) under a sulfur loading of 7.5 mg cm^(-2) and a high stability over 500 cycles are *** work demonstrates a feasible strategy of utilizing a laminar separator interlayer for advanced Li–S batteries awaiting commercialization and may shed light on the understanding of heterostructure catalysis with enhanced reaction kinetics.

关键词： Lithium-sulfur battery Heterogeneous catalysis Heterostructure Redox kinetics Lithium dendrites

The interaction of the structure-directing agent with the zeolite framework determines germanium distribution in SCM-15 germanosilicate

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Frontiers of Chemical Science and Engineering 2024年第5期18卷 105-114页

作者： Stoyan P.Gramatikov Petko St.Petkov Zhendong Wang Weimin Yang Georgi n.Vayssilov Faculty of Chemistry and Pharmacy University of Sofia1126 SofiaBulgaria State Key Laboratory of Green Chemical Engineering and Industrial Catalysis Sinopec Shanghai Research Institute of Petrochemical Technology Co.Ltd.Shanghai 201208China

We report results from computational modeling of the relative stability of germanosilicate SCM-15 structure due to different distribution of germanium heteroatoms in the double four-member rings(d4Rs)of the framework and the orientation of the structure directing agent(SdA)molecules in the as-synthesized *** calculated relative energies of the bare zeolite framework suggest that structures with germanium ions clustered in the same d4Rs,e.g.,with large number of Ge–O-Ge contacts,are the most *** simulations of various orientations of the SdA in the pores of the germanosilicate zeolite show different stability order-the most stable models are the structures with germanium spread among all ***,for SCM-15 the stabilization due to the presence of the SdA and their orientation,is thermodynamic factor directing both the formation of specific framework type and Ge distribution in the framework during the *** relative stability of bare structures with different germanium distribution is of minor *** differs from SCM-14 germanosilicate,reported earlier,for which the stability order is preserved in presence of ***,even for zeolites with the same chemical composition and SdA,the characteristics of their framework lead to different energetic preference for germanium distribution.

关键词： zeolite density functional theory structure-directing agent SCM-15

Further investigation on the fusion of ^(6)Li with ^(209)Bi target at near-barrier energies

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Chinese Physics C 2024年第7期48卷 106-117页

作者：张高龙焦振威张广鑫 M.R.Cortes 胡世鹏钱建强 d.Mengoni 屈卫卫李聪博郑云张焕乔孙慧斌王楠张春雷 J.J.Valiente-dobón d.Testov M.Mazzocco A.Gozzelino C.Parascandolo d.Pierroutsakou M.La Commara A.Goasduff d.Bazzacco d.R.napoli F.Galtarossa F.Recchia A.Illana S.Bakes I.Zanon S.Aydin G.de Angelis M.Siciliano R.Menegazzo S.M.Lenzi J.L.Ferreira J.Rangel Serkan Akkoyun L.F.Canto J.Lubian School of Physics Beihang UniversityBeijing 100191China Sino-French Institute of nuclear Engineering and Technology Sun Yat-Sen UniversityZhuhai 519082China Instituto de Física Universidade Federal Fluminense24210-340NiteróiRio de JaneiroBrazil Institute for Advanced Study in nuclear Energy&Safety Shenzhen UniversityShenzhen 518060China Shenzhen Key Laboratory of Research and Manufacture of High Purity Germanium Materials and Fetectors Shenzhen UniversityShenzhen 518060China InFn Sezione di PadovaPadovaItaly dipartimento di fisica Astronomia dell'Universita di padova PadovaItaly State Key Laboratory of Radiation Medicine and Protection School of Radiation Medicine and ProtectionSoochow UniversitySuzhou 215123China China Institute of Atomic Energy Beijing 102413China The Key Laboratory of Beam Technology and Material Modification of Ministry of Education College of Nuclear Science and TechnologyBeijing Normal UniversityBeijing 100875China InFn Laboratori Nazionali di LegnaroI-35020 LegnaroItaly InFn Sezione di NapoliI-80126 NapoliItaly dipartimento di Farmacia Universitàdi Napoli"Federico II"I-80131 NapoliItaly department of natural and Mathematical Sciences Faculty of EngineeringTarsus University33480 MersinTurkiye Physics division Argonne National LaboratoryLemont-ILUSA departamento de Matemaética Física e Computaç˜ao Universidade do Estado do Rio de JaneiroFaculdade de Tecnologia27537-000ResendeRio de JaneiroBrazil department of Physics Sivas Cumhuriyet UniversitySivasTurkey Instituto de Física Universidade Federal do Rio de JaneiroCP 6852821941-972Rio de JaneiroBrazil

The complete and incomplete fusion cross sections for ^(6)Li+^(209)Bi were measured using the in-beamγ-ray method around the Coulomb *** cross sections of(deuteron captured)incomplete fusion(ICF)products were re-quantified experimentally for this reaction *** results reveal that the ICF cross section is equivalent to that of complete fusion(CF)above the Coulomb barrier and dominant near or below the Coulomb barrier.A theoretical calculation based on the continuum discretized coupled channel(CdCC)method was performed for the aforementioned CF and ICF cross sections;the result is consistent with the *** universal fusion function(UFF)was also compared with the measured CF cross section for different barrier parameters,demonstrating that the CF suppression factor is significantly influenced by the choice of potential,which can reflect both dynamic and static effects of breakup on the fusion process.

关键词： cross section incomplete fusion suppression factor weakly bound nuclei

Oligodendroctyes:the forgotten players of diabetes pathophysiology

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neural Regeneration Research 2024年第11期19卷 2349-2350页

作者： Juan Antonio López-Villodres Beatriz García-díaz departamento Fisiología Humana Histología HumanaAnatomía Patológica y Educación Física y DeportivaFacultad de MedicinaUniversidad de MálagaMálagaSpain UGC neurociencia.Instituto de Investigación Biomédica de Málaga y Plataforma en nanomedicina(IBIMA Plataforma Bionand) MálagaSpain

Oligodendrocytes(OLs),glial cells that provide myelin sheaths to axons in the central nervous system(CnS),have a dual ***,this myelin fatty cover around the axons protects the nerves and is crucial for the saltatory propagation of action *** and not less important,OLs provide trophic support to neurons and ***,OL metabolism is important for OL well-being and the proper accomplishment of their functions,and OL metabolism energetics directly affect the energy metabolism of neighboring neurons.

关键词： metabolism nerves myelin

deep optics preconditioner for modulation-free pyramid wavefront sensing

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Photonics Research 2024年第2期12卷 301-312页

作者： FELIPE GUZMÁn JORGE TAPIA CAMILO WEInBERGER nICOLÁS HERnÁndEZ JORGE BACCA BEnOIT nEICHEL ESTEBAn VERA School of Electrical Engineering Pontificia Universidad Católica de Valparaı´soValparaı´soChile department of Systems Engineering Universidad Industrial de SantanderBucaramangaColombia Laboratoire d’Astrophysique de Marseille MarseilleFrance

The pyramid wavefront sensor(PWFS)can provide the sensitivity needed for demanding adaptive optics applications,such as imaging exoplanets using the future extremely large telescopes of over 30 m of diameter(d).However,its exquisite sensitivity has a limited linear range of operation,or dynamic range,although it can be extended through the use of beam modulation—despite sacrificing sensitivity and requiring additional optical *** by artificial intelligence techniques,this work proposes to train an optical layer—comprising a passive diffractive element placed at a conjugated Fourier plane of the pyramid prism—to boost the linear response of the pyramid sensor without the need for cumbersome *** develop an end-2-end simulation to train the diffractive element,which acts as an optical preconditioner to the traditional least-square modal phase estimation *** results with a large range of turbulence conditions show a noticeable improvement in the aberration estimation performance equivalent to over 3λ∕d of modulation when using the optically preconditioned deep PWFS(dPWFS).Experimental results validate the advantages of using the designed optical layer,where the dPWFS can pair the performance of a traditional PWFS with 2λ∕d of *** and adding an optical preconditioner to the PWFS is just the tip of the iceberg,since the proposed deep optics methodology can be used for the design of a completely new generation of wavefront sensors that can better fit the demands of sophisticated adaptive optics applications such as ground-to-space and underwater optical communications and imaging through scattering media.

关键词： process optics pyramid