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The effect of the magnetic fields from three different configurations of the MRIgRT systems on the dose deposition from lateral opposing photon beams in a laryngeal geometry–A Monte Carlo study

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Radiation Medicine and Protection 2021年第3期2卷 103-111页

作者： Vivien W.S.Chu Monica W.k.kan louis k.y.lee kenneth C.W.Wong Macy Tong Anthony T.C.Chan Department of Clinical Oncology Prince of Wales HospitalHong KongChina Department of Clinical Oncology The Chinese University of Hong KongHong KongChina Medical Center The Chinese University of Hong KongChina State key Laboratory of Translational Oncology Sir YK Pao Center for CancerDepartment of Clinical OncologyHong Kong Cancer Institute and Prince of Wales HospitalThe Chinese University of Hong KongHong KongChina

Objective:To investigate the impact of different magnetic field strengths and orientations on the dose deposition from lateral opposing photon beams irradiating a laryngeal geometry,with particular attention focused on the dose homogeneity of the area around the air cavity inside the ***:Geant4 simulation toolkit was used to perform Monte Carlo simulations on a phantom resembling the *** energy spectrum of a 6 MV photon beam from a Varian Clinac iX machine was used to provide the source of *** configurations of the Magnetic Resonance Image-Guided Radiation Therapy(MRIgRT)system were simulated:the Fixed Cylindrical(FC)geometry,the Longitudinal Rotating Biplanar(LRBP)geometry,and the Transverse Rotating Biplanar(TRBP)*** magnetic fields of different field strengths were *** relative dose maps and the homogeneity index(HI)were obtained for ***:The LRBP geometry together with a magnetic field strength of 0.5 T produced the most homogeneous dose distribution with a HI of 0.139 for the region of interest around the air cavity,compared with a HI of 0.180 when the magnetic field was *** TRBP geometry,the dose distribution shifted towards the cranial direction,leading to a region of hot spots at the superior edge and a region of cold spots at the inferior edge of the irradiated *** HI around the air cavity was therefore *** addition,strong electron streaming effect(ESE)was *** the FC geometry,hot and cold spots were formed around the air cavity which increased the ***:Out of the three configurations of the MRIgRT systems,the LRBP geometry produced the most clinically beneficial dose distribution in which it provided a higher dose to the treatment area and a boost in dose to the tissue immediately adjacent to the air cavity.

关键词： Monte Carlo MRIgRT MR-Linac Magnetic field Air cavity

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Scanning transmission electron microscopy and atom probe tomography analysis of non-stoichiometry long-period-stacking-ordered structures in Mg-Ni-y/Sm alloys

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Journal of Magnesium and Alloys 2024年第3期12卷 954-965页

作者： yimeng Chen Manuel Legrée Jean-louis Bobet Alexander kvit CAMECA Instruments Inc MadisonWI 53711USA ICMCB Universitéde BordeauxPessacCEDEX 33608France NIAC&Materials Science Department University of WisconsinMadisonWI 53706USA

The long-period-stacking-ordered(LPSO)structure affects the mechanical,corrosion and hydrolysis properties of Mg *** current work employs high angle annular dark field-scanning transmission electron microscopy(HAADF-STEM)and atom probe tomography(APT)to investigate the structural and local chemical information of LPSO phases formed in Mg-Ni-y/Sm ternary alloys after extended isothermal *** on the alloying elements and their concentrations,Mg-Ni-y/Sm develops a two-phase LPSO+α-Mg structure in which the LPSO phase contains defects,hybrid LPSO structure,and Mg ***-STEM and APT indicate non-stoichiometric LPSO with incomplete Ni_(6)(y/Sm)_(8) *** addition,the APT quantitatively determines the local composition of LPSO and confirms the presence of Ni within the Mg bonding *** results provide insight into a better understanding of the structure and hydrolysis properties of LPSO-Mg alloys.

关键词： Magnesium alloys Long-range ordering Atom probe tomography(APT) STEM HAADF Hydrolysis properties.

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The Norton anthology of African American literature / Henry louis Gates, Jr., general editor, Nellie y. Mckay, general editor. 2nd ed.

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2004年

作者： Henry louis Gates Jr. general editor Nellie y. Mckay general editor.

来源：畅想之星图书光盘版（南... 评论

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Presence of extensive intraductal component in patients undergoing breast conservative surgery predicts presence of residual disease in subsequent completion mastectomy

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Chinese Medical Journal 2009年第8期122卷 900-905页

作者： Christopher C. E yiu Wings T. y. Loo C. k. Lam louis W. C. Chow UNIMED Medical Institute Comprehensive Centre for Breast Diseases Hong Kong China Clinical Trial Centre Li Ka Shing Faculty of Medicine University of Hong Kong China

Background Local recurrence remains a serious problem among patients undergoing breast conservative surgery. This study aimed at identifying risk factors for residual disease after breast conservative surgery. Methods This retrospective study was based on patients with invasive breast cancer who have received breast conservative surgery and subsequent completion mastectomy. All patients had a clear resection margin in the initial operation. We analyzed the association between the presence of residual disease during completion mastectomy and the following risk factors： T staging, young age, and presence of extensive intraductal component （EIC）, a close margin, lymphovascular permeation （LVP）, positivity of estrogen receptor, progesterone receptor, and c-erbB-2. Results Residual disease was encountered in 21 （45.7%） of 46 patients; EIC was present in 28 patients （60.9%）, of whom 17 had residual disease. Presence of EIC during breast conservation surgery was associated with a higher risk of residual disease during completion mastectomy （P=0.011）. Other variables were not statistically significant risk factors for presence of residual disease. No local recurrence was recorded in our cohort, and the disease-free survival and overall survival after completion mastectomy were similar for patients who had residual disease and those who had not. Conclusions The presence of EIC is a significant risk factor for residual disease in patients after breast conservative surgery. Our findings may suggest the indicated value of completion mastectomy in patients with EIC during initial breast conservative surgery to decrease the risk of subsequent local failure.

关键词： extensive intraductal component breast conservative surgery residual disease completion mastectomy

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Charge balance materials for homojunction and heterojunction OLED applications

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Frontiers of Optoelectronics 2009年第4期2卷 435-441页

作者： louis M.LEUNG yik-Chung LAW Michael y.WONG Tik-Ho lee kin Ming LAI Lok-yee TANG Department of Chemistry and Centre for Advanced Luminescence Materials Hong Kong Baptist University

In a homojunction device, a single organic layer assumes the multiple roles of hole, electron transportation, and emitter. Its ease in processing is highly desirable from the manufacturing point of view. In this paper, we shall describe the synthesis of a range of bipolar small molecules and conductive vinyl polymers for application in homojunction and heterojunction organic light emitting diodes（OLEDs）. The bipolar materials, in general, consist of three basic building blocks: an arylamine, a 1,3,4-oxadiazole, and a polycyclic aromatic moiety. The achievement of charge balance can be validated either by direct measurement of electron/hole mobility or indirectly via optimization of device properties.A series of conductive vinyl copolymers containing hole transporting N-（4-methoxyphenyl）-N-（4-vinylphenyl）naphthalen-1-amine（4MeONPA） and electron transporting 2-phenyl-5-（4-vinylphenyl）-1,3,4-oxadiazole（OXA）at different compositions was applied for heterojunction and homojunction OLEDs. For heterojunction devices employed the copolymers as the hole transporting layer and Alq3as the electron transporting and emitting layer,a maximum luminance and current efficiency of over 23000 cd/m2and 4.2 cd/A（PL of Alq3）, respectively, were achieved at the charge balance composition. Homojunction devices for the copolymers were demonstrated by the addition of rubrene as a dopant. The single layer devices at the optimal copolymer composition has ca 1500 cd/m2and 0.74 cd/A.

关键词： homojunction devices charge balance bipolar small molecules conductive vinyl copolymers

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Numerical Modeling of Mass Transfer in the Interaction between River Biofilm and a Turbulent Boundary Layer

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Open Journal of Fluid Dynamics 2024年第1期14卷 1-23页

作者： Falilou Coundoul Evrad M. D. Ngom Frédéric y. Moulin Institut Polytechnique de Saint-louis Université Gaston Berger Saint-Louis Senegal Institut de Mécanique des Fluides de Toulouse UMR 5502-Université de Toulouse Occitanie France

In this article dedicated to the modeling of vertical mass transfers between the biofilm and the bulk flow, we have, in the first instance, presented the methodology used, followed by the presentation of various results obtained through analyses conducted on velocity fields, different fluxes, and overall transfer coefficients. Due to numerical constraints (resolution of relevant spatial scales), we have restricted the analysis to low Schmidt numbers (Sc=0.1, Sc=1, and Sc=10) and a single roughness Reynolds number (Re*=150). The analysis of instantaneous concentration fields from various simulations revealed logarithmic concentration profiles above the canopy. In this zone, the concentration is relatively homogeneous for longer times. The analysis of results also showed that the contribution of molecular diffusion to the total flux depends on the Schmidt number. This contribution is negligible for Schmidt numbers Sc≥0.1, but nearly balances the turbulent flux for Sc=0.1. In the canopy, the local Sherwood number, given by the ratio of the total flux (within or above the canopy) to the molecular diffusion flux at the wall, also depends on the Schmidt number and varies significantly between the canopy and the region above. The exchange velocity, a purely hydrodynamic parameter, is independent of the Schmidt number and is on the order of 10% of in the present case. This study also reveals that nutrient absorption by organisms near the wall depends on the Schmidt number. Such absorption is facilitated by lower Schmidt numbers.

关键词： Epilithic Biofilm Passive Scalar Transport Direct Numerical Simulation Navier-Stokes

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Regulation of Myelination in the Central Nervous System by Nuclear Lamin B1 and Non-coding RNAs

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Translational Neurodegeneration 2014年第1期3卷 13-20页

作者： Shu-Ting Lin Mary y Heng louis J Ptáček ying-Hui Fu Department of Neurology University of California1550 Fourth streetUCSF-Mission BayRock Hall 548San FranciscoCA 94158USA Howard Hughes Medical Institute University of CaliforniaSan FranciscoCA 94158USA

Adult-onset autosomal dominant leukodystrophy(ADLD)is a progressive and fatal hereditary demyelination disorder characterized initially by autonomic dysfunction and loss of myelin in the central nervous system(CNS).Majority of ADLD is caused by a genomic duplication of the nuclear lamin B1 gene(LMNB1)encoding lamin B1 protein,resulting in increased gene dosage in brain *** vitro,excessive lamin B1 at the cellular level reduces transcription of myelin genes,leading to premature arrest of oligodendrocyte *** models of ADLD overexpressing LMNB1 exhibited age-dependent motor deficits and myelin defects,which are associated with reduced occupancy of the yin yang 1 transcription factor at the promoter region of the proteolipid protein *** B1 overexpression mediates oligodendrocyte cell-autonomous neuropathology in ADLD and suggests lamin B1 as an important regulator of myelin formation and maintenance during *** of microRNA-23(miR-23)as a negative regulator of lamin B1 can ameliorate the consequences of excessive lamin B1 at the cellular ***-23a-overexpressing mice display enhanced oligodendrocyte differentiation and myelin ***-23a targets include a protein coding transcript PTEN(phosphatase and tensin homolog on chromosome 10),and a long noncoding RNA(2700046G09Rik),indicating a unique role for miR-23a in the coordination of proteins and noncoding RNAs in generating and maintaining healthy ***,we provide a concise review of the current literature on clinical presentations of ADLD and how lamin B1 affects myelination and other developmental ***,we address the emerging role of non-coding RNAs(ncRNAs)in modulating gene networks,specifically investigating miR-23 as a potential target for the treatment of ADLD and other demyelinating disorders.

关键词： Lamin Long non-coding RNA MicroRNA Myelin

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Practice of breast self-examination among high risk Chinese women in Hong kong

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Chinese Medical Journal 2000年第12期 44-47页

作者： kelvin k C Ng, Fung S y and louis W C Chow DepartmentofSurgery (NgkkCandChowLWC)&NursingStudies (FungSy ) ,TheUniversityofHongkong ,QueenMaryHospital ,Hongkong ,China

Background The incidence of breast cancer in Hong kong is increasing and breast serf-examination (BSE)as a screening tool is becoming mere popular,especially among first-dsgree relatives (FDR) of breast cancer victims. BSE may be mere applicable to Chinese women as their breast size is smaller. This study explores the BSE practice in this group of *** A cross sectional study was conducted by sending questionnaires to 330 FDR of breast cancer patients treated in the Department of Surgeory,Univeisity of Hong kong. BSE behavior was studied with respect to its frequency,awareness,completeness and confidence of *** 110 subjects returned the questionnaires with a response rate of 33%.The mean age of the respondent was 37 years. Only 57 women (52%)were practicers. The practicers have a stronger BSE awareness (p＜0.01) and a lower mean score on thought barriers (P=0.002) than the non-practicers.40% of the practicers gain their BSE knowledge through clinicians and their mean period of practica was 3.2 yeara. 68% of the practicers performed BSE *** overall confidence rate was 35%, but the rate was 43% among those who performled complete *** factors possibly related to the completeness and rate of confidence of BSF examination were *** only factor that significantly deternined completenass was the time spent for each examination (P=0.002).The complete practicers required a longer time than the incomplete practicers(6.60 and 2.96 min,respectively).Women with a stronger BSE intention (P=0.001)and a lower mean score on thought barrers(P=0.001)performed the examination *** Slightly over half of the FDR practice *** majority perform a complete BSE but they are not confident in finding abnormalities. Women spending more time on BSE are associated with a higher rate of completeness. However,only those with a stronger DSE: intention and lesser thought barriers are more confident in their practice.

关键词： breast self-examination first-degree relative Chinese

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Ru complex and N,P-containing polymers confined within mesoporous hollow carbon spheres for hydrogenation of CO_(2)to formate

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Nano Research 2023年第4期16卷 4515-4523页

作者： Guoxiang yang yasutaka kuwahara kohsuke Mori Catherine louis Hiromi yamashita Division of Materials and Manufacturing Science Graduate School of EngineeringOsaka University2-1 Yamada-okaSuitaOsaka 565-0871Japan Institute for Open and Transdisciplinary Research Initiatives(OTRI) Osaka University2-1 Yamada-okaSuitaOsaka 565-0871Japan Unit of Elements Strategy Initiative for Catalysts&Batteries(ESICB) Kyoto UniversityKatsuraKyoto 615-8520Japan JST PRESTO4-1-8 HonchoKawaguchiSaitama 332-0012Japan Sorbonne Université CNRSLaboratoire de Réactivitéde SurfaceLRSF-75005 ParisFrance

The development of reliable catalysts with both excellent activity and recyclability for carbon dioxide(CO_(2))hydrogenation is ***,a ternary hybrid heterogeneous catalyst,involving mononuclear Ru complex,N,P-containing porous organic polymers(POPs),and mesoporous hollow carbon spheres(Ru^(3+)-POPs@MHCS)is reported for CO_(2)hydrogenation to *** on comprehensive structural analyses,we demonstrated that Ru^(3+)-POPs were successfully immobilized within *** optimized Ru^(3+)-0.5POPs@MHCS catalyst,which was obtained with about 5 wt.%Ru^(3+)and 0.5 mmol POPs polymers confined into 0.3 g MHCS,exhibited high catalytic activity for CO_(2)hydrogenation to formate(turnover number(TON)>1,200 for 24 h under mild reaction conditions(4.0 MPa,120℃))and improved durability,compared to Ru^(3+)catalysts without POPs polymers(Ru^(3+)-MHCS)and unencapsulated MHCS(Ru^(3+)-0.5POPs)*** improved catalytic performance is attributed to the high surface area and large pore volume of MHCS which favors dispersion and stabilization of Ru^(3+)-***,the MHCS and POPs showed high CO_(2)adsorption ***^(3+)-POPs encapsulated into MHCS reduces the activation energy barrier for CO_(2)hydrogenation to formate.

关键词： heterogeneous catalysis porous organic polymers(POPs) mesoporous hollow carbon spheres CO_(2)hydrogenation formate synthesis

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GLOBAL WELL-POSEDNESS AND BLOW-UP FOR THE HARTREE EQUATION

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Acta Mathematica Scientia 2017年第4期37卷 941-948页

作者：杨凌燕李晓光吴永洪 louis CACCETTA Sichuan Normal University Chengdu610066China Wuhan Institute of Physics and Machematics Chinese Academy of Science Wuhan 430071China Department of Mathematics and Statistics Curtin University of TechnologyPerthWA 6845Australia

For 2 〈 y 〈 min{4, n}, we consider the focusing Hartree equation iut ＋ Au ＋（｜x｜^-γ ＊｜u｜2）u = O, x∈ R^n Let M[u] and E[u] denote the mass and energy, respectively, of a solution u, and Q be the ground state of - △ ＋ Q = （｜x｜^-γ ＊｜Q｜^2）Q. Guo and Wang [Z. Angew. Math. Phy.,2014] established a dichotomy for scattering versus blow-up for the Cauchy problem of （0,1） if M[u]^l-ScE[u]^Sc 〈 M[Q] ^1-sc E[Q] ^（sc= r-2/2）. In this paper, we consider the complementary case M[u]^1-ScE[u]^sc 〉_ M[Q]^1-sc and obtain a criteria on blow-up and global existence for the Hartree equation （0.1）.

关键词： Hartree equation Threshold criteria blow-up solution

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