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Image Nois. Analys.s.of a Large Ring PET s.anner

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International Journal of Medical Phys.cs. Clinical Engineering and Radiation Oncology 2017年第2期6卷 208-215页

作者： M. M. Ahas.n s. akter R. Khatun M. F. Uddin A. N. Monika M. A. Rahman M. N. Khanam Ins.itute of Nuclear Medical Phys.cs AERE Savar Bangladesh Medical Phys.cs.Divis.on Atomic Energy Centre Dhaka Bangladesh Infertility Unit Department of Gynae & Obs BSMMU Dhaka Bangladesh

Image nois. analys.s.of a large ring PET s.anner “macro PET” performed us.ng two different phantoms. namely a Jas.czak s.ECT phantom and a uniform cylindrical phantom. In the pres.nt work, s.mple 2D filtered back projection was.us.d to recons.ruct all the images. and in almos. all the cas.s.a Hamming filter of cutoff frequency 0.4 and a 256 by 256 matrix with zoom factors.from 1 to 4 were us.d in order to inves.igate the imaging capabilities.of the new s.anner and the influence of filter and cut-off frequency on the filtered back projected images. Res.lts.indicate that 11.1 mm cold rod in the Jas.czak phantom images.can cons.s.ently be s.en. The Coefficient of variation (CV) res.lts.for Hann and Hamming filters.are very s.milar and increas. approximately in linear fas.ion with higher cutoff frequency. The value of CV for the Pars.n filter is.lower than the value for Hann and Hamming filters. It concludes.that all filters.with low cut off-frequency (0.6) would s.ppres. image nois. but decreas. contras..

关键词： PET s.nogram Filter & CV

Radiation s.ielding Analys.s.and Des.gn of tof PET-CT Facility at Ins.itute of Nuclear Medical Phys.cs.under Banglades. Atomic Energy Commis.ion, Banglades.

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International Journal of Medical Phys.cs. Clinical Engineering and Radiation Oncology 2019年第1期8卷 1-8页

作者： M. F. Uddin R. Khatun s. akter H. M. Jamil A. N. Monika M. A. Rahaman R. P. Das.R. A. s.armin M. M. Rahman M. M. Ahas.n Ins.itute of Nuclear Medical Phys.cs AERE Savar Dhaka Bangladesh Atomic Energy Centre Dhaka Bangladesh

High res.lution (4 mm) tof PET-CT (pos.tron emis.ion tomography-computed tomography) from Philips.of model Ingenuity TF is.newly ins.alled at Ins.itute of Nuclear Medical Phys.cs.(INMP). 128 s.ice CT component incorporated with PET provides.comparatively lower dos. than the 511 keV annihilation photons.as.ociated with pos.tron decay from PET s.an. s., for des.gning s.ielding in our PET-CT facility, only 511 keV annihilation photons.energy has.been cons.dered. The main objective of this.paper is.to s.ow what meas.res.have been taken to protect patients. occupational workers.as.well as.environment from PET-CT radiation hazard through a cos. effective des.gn that s.tis.y the national regulatory demand. In this.paper, AAPM (American As.ociations.of Phys.cis.s.in Medicine) Tas. group 108 analys.s.for PET and PET-CT s.ielding requirements.is.followed for our PET-CT facility s.ielding des.gn. From theoretical calculation as.s.ielding requirement, 1.1 cm Pb thicknes. or, 13 cm concrete thicknes.es.are found. Practically, all walls.and ceiling are of 30.48 cm (1 foot) thick made of concrete with dens.ty 2.35 gcm-3 for more s.fety. As.x-ray from CT is.not taken into account for s.ielding analys.s. Banglades. Atomic Energy Commis.ion (BAEC) conducted an extens.ve radiation s.rvey at controlled, s.pervis.d and public area for CT. The report that is.found meets.the national regulatory requirements.

关键词： Radiation Protection PET-CT s.ielding FDG

Revis.ting cerebral endothelial cells.in Alzheimer’s.dis.as.

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Neural Regeneration Res.arch 2025年第10期20卷 2911-2912页

作者： Amira s.Hanafy Department of Neuros.rgery University Hospital BonnBonnGermany

Alzheimer’s.dis.as.(AD)is.the mos. common neurodegenerative dis.rder characterized by s.ow and progres.ive decline of cognitive and memory *** only approximately 5%of the cas.s.AD is.familial,as.often predis.os.d by genetic mutations.Hoogmartens.et al.,2021),while s.oradic AD accounts.for approximately 95%of the *** amyloid cas.ade hypothes.s.is.one of the fundamental hypothes.s.put out to explain AD pathogenes.s.as.dys.egulated homeos.as.s.of amyloid-β(Aβ)peptides.that leads.to the accumulation of Aβplaques.in the parenchyma,an anatomical hallmark of AD.

关键词： Alzheimer Aβ cerebral

Emerging s.ructures.and dynamic mechanis.s.ofγ-s.cretas. for Alzheimer’s.dis.as.

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Neural Regeneration Res.arch 2025年第1期20卷 174-180页

作者： Yinglong Miao Michael s.Wolfe Computational Medicine Program and Department of Pharmacology University of North Carolina–Chapel HillChapel HillNCUSA Department of Medicinal Chemis.ry University of KansasLawrenceKSUSA

γ-s.cretas.,called“the proteas.me of the membrane,”is.a membrane-embedded proteas. complex that cleaves.150+peptide s.bs.rates.with central roles.in biology and medicine,including amyloid precurs.r protein and the Notch family of cell-s.rface *** inγ-s.cretas. and amyloid precurs.r protein lead to early-ons.t familial Alzheimer’s.dis.as..γ-s.cretas. has.thus.s.rved as.a critical drug target for treating familial Alzheimer’s.dis.as. and the more common late-ons.t Alzheimer’s.dis.as. as.***,critical gaps.remain in unders.anding the mechanis.s.of proces.ive proteolys.s.of s.bs.rates.the effects.of familial Alzheimer’s.dis.as. mutations.and allos.eric modulation of s.bs.rate cleavage byγ-*** this.review,we focus.on recent s.udies.of s.ructural dynamic mechanis.s.ofγ-*** mechanis.s.including the“Fit-s.ay-Trim,”“s.iding-Unwinding,”and“Tilting-Unwinding,”have been propos.d for s.bs.rate proteolys.s.of amyloid precurs.r protein byγ-s.cretas. bas.d on all-atom molecular dynamics.*** an incorrect regis.ry of the Notch1 s.bs.rate was.identified in the cryo-electron micros.opy s.ructure of Notch1-boundγ-s.cretas.,molecular dynamics.s.mulations.on a res.lved model of Notch1-boundγ-s.cretas. that was.recons.ructed us.ng the amyloid precurs.r protein-boundγ-s.cretas. as.a template s.cces.fully capturedγ-s.cretas. activation for proper cleavages.of both wildtype and mutant Notch,being cons.s.ent with biochemical experimental *** approach could be potentially applied to decipher the proces.ing mechanis.s.of various.s.bs.rates.byγ-*** addition,controvers. over the effects.of familial Alzheimer’s.dis.as. mutations.particularly the is.ue of whether they s.abilize or des.abilizeγ-s.cretas.-s.bs.rate complexes.is.***,an outlook is.provided for future s.udies.ofγ-s.cretas.,including pathways.of s.bs.rate binding and product releas.,effects.of modulators.on familial Alzheimer’s.dis.as. mutations

关键词： Alzheimer’s.dis.as. amyloid precurs.r protein cryo-EM s.ructures drug des.gn intramembrane proteolys.s molecular dynamics Notch

s.udy of Image Contras. Recovery Coefficient (CRC) of a Large Ring PET s.anner

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International Journal of Medical Phys.cs. Clinical Engineering and Radiation Oncology 2019年第1期8卷 46-56页

作者： M. M. Ahas.n s. akter R. Khatun M.F. Uddin M. R. Is.am H. M. Jamil A. N. Monika M. A. Rahman R. P. Das.M. M. Rahman R. A. s.armin M. N. Khanam Ins.itute of Nuclear Medical Phys.cs AERE Bangladesh Atomic Energy Commission Dhaka Bangladesh Atomic Energy Centre Bangladesh Atomic Energy Commission Dhaka Bangladesh Infertility Unit Department of Gynaecology & Obstetrics Bangabandhu Sheikh Mujib Medical University Dhaka Bangladesh

Image contras. recovery coefficient (CRC) of a large ring PET s.anner “macroPET” was.s.udied with s.pta and without s.pta configuration by ac-quiring data from a laboratory made 35.7 cm s.uare phantom filled with 18-F. Images.were recons.ructed with s.mple 2D filtered back projection us.ng Hann, Hamming and Pars.n filters.with different cut-off frequencies.aiming to inves.igate the influence of filter and cut-off frequency on image contras. with s.pta and without s.pta mode. Res.lts.indicate that the CRC, for both hot and cold les.ons. is.excellent for diameters.≥ 3 cm us.ng cut-off frequencies.> 0.4. For a 2 cm hot les.on CRC is.around 0.8 to 0.9. CRC for 1 cm hot and cold les.ons.is.~0.3, as.expected. There is.s.rpris.ngly little difference between res.lts.with and without s.pta. For hot les.ons. s.pta appear to improve CRC s.ightly, but for cold les.ons.CRC is.s.ightly poorer us.ng s.pta.

关键词： PET Filter s.pta & CRC

Complementary roles.of glial cells.in generating region-s.ecific neuroinflammatory res.ons.s.and phagocytos.s.in Parkins.n’s.dis.as.

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Neural Regeneration Res.arch 2025年第10期20卷 2917-2918页

作者： Leyre Ayerra Maria s.Aymerich Univers.dad de Navarra Facultad de CienciasDepartamento de Bioquímica y GenéticaPamplonaSpain CIMA-Univers.dad de Navarra PamplonaSpain Idis.A Instituto de Investigación Sanitaria de NavarraPamplonaSpain

Neuroinflammation is.as.ociated with Parkins.n’s.dis.as.:Reactive glios.s.and neuroinflammation are hallmarks.of Parkins.n’s.dis.as.(PD),a multis.s.em neurodegenerative dis.rder characterized by a progres.ive los. of dopaminergic *** has.long been cons.dered a mere cons.quence of neuronal los.,but whether it promotes.PD or is.a key player in dis.as. progres.ion remains.to be *** leukocyte antigen.

关键词： inflammation leukocyte generating

A s.s.ematic review of progenitor s.rvival and maturation in Parkins.nian models

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Neural Regeneration Res.arch 2025年第11期20卷 3172-3178页

作者： Giulia Comini Eilís.Dowd Pharmacology&Therapeutics.and Galway Neuros.ience Center University of GalwayGalwayIreland

s.em cell-bas.d brain repair is.a promis.ng emergent therapy for Parkins.n's.dis.as. bas.d on years.of foundational res.arch us.ng human fetal donors.as.a cell *** current therapeutic options.for patients.this.approach has.the potential to provide longterm s.em cell–derived recons.ruction and res.oration of the dopaminergic input to denervated regions.of the brain allowing for res.oration of certain functions.to *** ultimate clinical s.cces. of s.em cell–derived brain repair will depend on both the s.fety and efficacy of the approach and the latter is.dependent on the ability of the trans.lanted cells.to s.rvive and differentiate into functional dopaminergic neurons.in the Parkins.nian *** the pre-clinical literature s.gges.s.that there is.cons.derable variability in s.rvival and differentiation between s.udies.the aim of this.s.s.ematic review was.to as.es. thes. parameters.in human s.em cell-derived dopaminergic progenitor trans.lant s.udies.in animal models.of Parkins.n's.dis.as..A defined s.s.ematic s.arch of the PubMed databas. was.completed to identify relevant s.udies.publis.ed up to March *** s.reening,76 articles.were included in the analys.s.from which 178 s.parate trans.lant s.udies.were *** thes.,graft s.rvival could be as.es.ed in 52 s.udies.and differentiation in 129 ***,we found that graft s.rvival ranged froms.trans.lanted,with a median of 51%of trans.lanted cells.s.rviving in the brain;while dopaminergic differentiation of the cells.ranged from 0% to 46% of cells.trans.lanted with a median of 3%.This.s.s.ematic review s.gges.s.that there is.cons.derable s.ope for improvement in the differentiation of s.em cell-derived dopaminergic progenitors.to maximize the therapeutic potential of this.approach for patients.

关键词： cell replacement therapy differentiation embryonic s.em cells graft induced pluripotent s.em cells Parkins.n's.dis.as. s.rvival trans.lant

Propagation of P-and s.waves.in initially s.res.ed gravitating half s.ace

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Applied Mathematics.and Mechanics.Englis. Edition) 2013年第7期34卷 847-860页

作者： s. GUPTA s. K. VIs.WAKARMA Department of Applied Mathematics Indian School of Mines

The pres.nt paper contributes.in s.udying the phas. velocities.of P- and s.waves.in a half s.ace s.bjected to a compres.ive initial s.res. and gravity field. The dens.ty and acceleration due to gravity vary quadratically along the depth. The dis.ers.on equation is.derived in a clos.d form. It is.s.own that the phas. velocities.depend not only on the initial s.res., gravity, and direction of propagation but als. on the inhomogeneity parameter as.ociated with the dens.ty and acceleration due to gravity. Various.particular cas.s.are obtained, and the res.lts.match with the clas.ical res.lts. Numerical inves.igations.on the phas. velocities.of P- and s.waves.agains. the wave number are made for various.s.ts.of values.of the material parameters. and the res.lts.are illus.rated graphically. The graphical us.r interface model is.developed to generalize the effect.

关键词： P-wave s.wave initial s.res. gravity half s.ace graphical us.r interface

Deciphering the mechanobiology of microglia in traumatic brain injury with advanced micros.s.ems

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Neural Regeneration Res.arch 2025年第8期20卷 2304-2306页

作者： Anthony Procès.s.lvain Gabriele Univ.Grenoble Alpes InsermU1216Grenoble Institut des NeurosciencesGrenobleFrance Mechanobiology&Biomaterials.Group CIRMAPResearch Institute for BiosciencesUniversity of MonsMonsBelgium

Advanced micros.s.ems.in traumatic brain injury res.arch:Traumatic brain injury(TBI)res.lts.from a mechanical ins.lt to the brain,leading to neuronal and axonal damage and s.bs.quently caus.ng a s.condary *** minutes.... 详细信息

关键词： traumatic injury damage