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Brain-derived neurotrophic factor signaling in the neuromuscular junction during developmental axonal competition and synapse elimination

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Neural Regeneration Research 2025年第2期20卷 394-401页

作者： Josep Tomàs Víctor cilleros-Mañé Laia Just-Borràs Marta Balanyà-segura Aleksandra Polishchuk Laura Nadal Marta Tomàs carolina silvera-simón Manel M.santafé Maria A.Lanuza Unitat d’Histologia i Neurobiologia(UHNeurob) Facultat de Medicina i Ciències de la SalutUniversitat Rovira i VirgiliReusSpain

During the development of the nervous system,there is an overproduction of neurons and *** competition between neighboring nerve endings and synapses performing different activity levels leads to their elimination or *** have extensively studied the involvement of the brain-derived neurotrophic factor-Tropomyosin-related kinase B receptor neurotrophic retrograde pathway,at the neuromuscular junction,in the axonal development and synapse elimination process versus the synapse *** purpose of this review is to describe the neurotrophic influence on developmental synapse elimination,in relation to other molecular pathways that we and others have found to regulate this *** particular,we summarize our published results based on transmitter release analysis and axonal counts to show the different involvement of the presynaptic acetylcholine muscarinic autoreceptors,coupled to downstream serine-threonine protein kinases A and c(PKA and PKc)and voltage-gated calcium channels,at different nerve endings in developmental *** dynamic changes that occur simultaneously in several nerve terminals and synapses converge across a postsynaptic site,influence each other,and require careful studies to individualize the mechanisms of specific *** describe an activity-dependent balance(related to the extent of transmitter release)between the presynaptic muscarinic subtypes and the neurotrophin-mediated TrkB/p75NTR pathways that can influence the timing and fate of the competitive interactions between the different axon *** downstream displacement of the PKA/PKc activity ratio to lower values,both in competing nerve terminals and at postsynaptic sites,plays a relevant role in controlling the elimination of supernumerary ***,calcium entry through L-and P/Q-subtypes of voltage-gated calcium channels(both channels are present,together with the N-type channel in developing nerve terminals)contributes to red

关键词： acetylcholine release adenosine receptors axonal competition brain-derived neurotrophic factor calcium channels motor end-plate muscarinic acetylcholine receptors postnatal synapse elimination serine kinases tropomyosin-related kinase receptorB

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A comprehensive investigation on nonlinear vibration and bending characteristics of bio-inspired helicoidal laminated composite structures

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 81-100页

作者： s.sAURABH R.KIRAN D.sINGH R.VAIsH V.s.cHAUHAN school of Mechanical and Materials Engineering Indian Institute of Technology Mandi

Bio-inspired helicoidal composite laminates, inspired by the intricate helical structures found in nature, present a promising frontier for enhancing the mechanical properties of structural designs. Hence, this study provides a comprehensive investigation into the nonlinear free vibration and nonlinear bending behavior of bio-inspired composite plates. The inverse hyperbolic shear deformation theory(IHsDT) of plates is employed to characterize the displacement field, with the incorporation of Green-Lagrange nonlinearity. The problem is modeled using the c0finite element method(FEM), and an in-house code is developed in the MATLAB environment to solve it numerically. Various helicoidal layup configurations including helicoidal recursive(HR), helicoidal exponential(HE), helicoidal semi-circular(Hs), linear helicoidal(LH), and Fibonacci helicoidal(FH)with different layup sequences and quasi-isotropic configurations are studied. The model is validated, and parametric studies are conducted. These studies investigate the effects of layup configurations, side-to-thickness ratio, modulus ratios, boundary conditions, and loading conditions at different load amplitudes on the nonlinear vibration and nonlinear bending behaviors of bio-inspired composite plates. The results show that the laminate sequence exerts a substantial impact on both nonlinear natural frequencies and nonlinear bending behaviors. Moreover, this influence varies across different side-to-thickness ratios and boundary conditions of the bio-inspired composite plate.

关键词： finite element method (FEM) nonlinear Green-Lagrange inverse hyperbolic shear deformation theory (IHsDT) bio-inspired composite plate helicoidal O322

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A Quantitative Analysis of Mn segregation at Partitioned Ferrite/Austenite Interface in a Fe-c-Mn-si Alloy

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Journal of Materials science & Technology 2009年第3期25卷 383-388页

作者： H. Guo s.w. Yang c.J.shang X.M. wang X.L. He Department of Materials Physics and chemistry University of Science and Technology Beijing Beijing 100083 China

Mn segregation at austenite/ferrite interface is studied in a Fe-c-Mn-si alloy held at 656℃. Mn is partitioned during the growth of ferrite and as a result, a Mn pile-up exists in front of interface on the matrix side. An approach to evaluate Mn segregation quantitatively is developed by combining sTEM raster window scanning and simulation of the interaction of the electron beam with the sample to subtract the contribution of Mn pile-up and obtain pure Mn segregation value. The evaluated maximum Mn interfacial segregation is in the order of a half-monolayer.

关键词： Interfacial segregation Phase transformation sTEM Beam broadening

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A functional tacrolimus-releasing nerve wrap for enhancing nerve regeneration following surgical nerve repair

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Neural Regeneration Research 2025年第1期20卷 291-304页

作者： simeon c.Daeschler Katelyn J.w.so Konstantin Feinberg Marina Manoraj Jenny cheung Jennifer Zhang Kaveh Mirmoeini JPaul santerre Tessa Gordon Gregory HBorschel sickKids Research Institute Neuroscience and Mental Health ProgramTorontoONCanada Institute of Biomaterials and Biomedical Engineering University of TorontoTorontoONCanada Indiana University school of Medicine IndianapolisINUSA Division of Plastic and Reconstructive surgery the Hospital for Sick ChildrenTorontoONCanada Translational Biology and Engineering Program Ted Rogers Centre for Heart ResearchInstitute of Biomedical EngineeringFaculty of DentistryUniversity of TorontoTorontoONCanada

Axonal regeneration following surgical nerve repair is slow and often incomplete,resulting in poor functional recovery which sometimes contributes to lifelong ***,there are no FDA-approved therapies available to promote nerve *** accelerates axonal regeneration,but systemic side effects presently outweigh its potential benefits for peripheral nerve *** authors describe herein a biodegradable polyurethane-based drug delivery system for the sustained local release of tacrolimus at the nerve repair site,with suitable properties for scalable production and clinical application,aiming to promote nerve regeneration and functional recovery with minimal systemic drug *** is encapsulated into co-axially electrospun polycarbonate-urethane nanofibers to generate an implantable nerve wrap that releases therapeutic doses of bioactive tacrolimus over 31 *** and drug loading are adjustable for applications in small and large caliber nerves,and the wrap degrades.w.thin 120 days into biocompatible *** released from the nerve wrap promotes axon elongation in vitro and accelerates nerve regeneration and functional recovery in preclinical nerve repair models.w.ile off-target systemic drug exposure is reduced by 80%compared with systemic *** its surgical suitability and preclinical efficacy and safety,this system may provide a readily translatable approach to support axonal regeneration and recovery in patients undergoing nerve surgery.

关键词： biodegradable local drug delivery nerve injury nerve regeneration nerve wrap tacrolimus

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sEAsONAL AND DIURNAL VARIATIONs OF PM_(1.0),PM_(2.5) AND PM_(10) IN THE ROADsIDE ENVIRONMENT OF HONG KONG

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china Particuology 2006年第6期4卷 312-315页

作者： K.F. Ho s.c. Lee s.w. Law Research center of Urban Environmental Technology and Management Department of Civil and Structural Engineering Hong Kong Polytechnic University Hung Hom Kowloon Hong Kong China

PM1.0 （fine particles, with diameter 〈 1 pm）, PM2.5 （fine particles, with diameter 〈 2.5μm） and PM10 （coarse particles, with diameter 〈 10 μm） were measured at 24-hour intervals near a high-traffic road in Hong Kong, from October 2004 to september 2005. Mass concentrations.w.re determined for the three particle fractions, averaging for PM1.0, PM2.5 and PM10, respectively, 44.5±18.4, 55.4±25.5 and 81.3±37.7μg·m^-3, PM2.5 was 3.7 times the U.s. EPA＇s annual NAAQs of 15 μg·m^-3,. Overall, PM1.0 accounted for 44 to 69% （average 57%） of PM10, while PM2.5 accounted for 58 to 82% （average 71%） in this study. The particulate masses showed obvious seasonal patterns.w.th high concentrations in cold seasons and low in warm seasons, especially high concentrations of PM2.5-10 during the cold seasons. Diurnal variations of mass concentrations of PM2.5 were determined during July, showing two major peaks in the morning and afternoon rush hours.

关键词： PM1.0 PM2.5 PM10 seasonal variations roadside environment Hong Kong

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The impact of alpha-fetoprotein (AFP), child-turcotte-pugh (cTP) score and disease staging on the survival of hepatocellular carcinoma (Hcc) patients: a retrospective cohort from single oncology center

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Oncology research 2025年第1期33卷 149-160页

作者： Nasser Mulla Yousef Katib Asim M Almughamsi Duaa s Alkhayat Mohamed Mosaad samir T Alfotih Rawan Alaofi Department of Internal Medicine Faculty of Medicine Taibah University Madinah 42278 Saudi Arabia. Department of Radiology Faculty of Medicine Taibah University Madinah 42278 Saudi Arabia. Department of surgery Faculty of Medicine Taibah University Madinah 42278 Saudi Arabia. Department of Endemic and Infectious Diseases Suez Canal University Ismailia 41522 Egypt. King salman bin Abdulaziz Medical city Madinah 42311 Saudi Arabia. Prince Mohammed Bin Abdulaziz Hospital Madinah 41511 Saudi Arabia.

Background:Hepatocellular carcinoma (Hcc) is the most common cause of cancer-related death in saudi Arabia. Our study aimed to investigate the patterns of Hcc and the effect of TNM staging, Alfa-fetoprotein (AFP), and child-Turcotte Pugh (cTP) on patients' overall survival (Os).Methods:A retrospective analysis.w.s conducted on 43 Hcc patients at a single oncology center in saudi Arabia from 2015 to 2020. All patients had to fulfill one of the following criteria: (a) a liver lesion reported as definitive Hcc on dynamic imaging and/or (b) a biopsy-confirmed diagnosis.Results:The mean patient age of all Hcc cases.w.s 66.8 with a male-to-female ratio of 3.3:1. All patients.w.re stratified into two groups: viral Hcc (n = 22, 51%) and non-viral Hcc (n = 21, 49%). Among viral-Hcc patients, 55% were due to HBV and 45% due to HcV. cirrhosis.w.s diagnosed in 79% of cases. Age and sex did not significantly statistically differ in Os among viral and non-viral Hcc patients (-value > 0.05). About 65% of patients had tumor size >5 cm during the diagnosis, with a significant statistical difference in Os (-value = 0.027). AFP was >400 ng/ml in 45% of the patients. There was a statistically significant difference in the Os in terms of AFP levels (-value = 0.021). A statistically significant difference was also observed between the cTP score and Os (-value = 0.02). cTP class B had the longest survival. Bsc was the most common treatment provided to Hcc patients followed by sorafenib therapy. There was a significant statistical difference in Os among viral and non-viral Hcc patients (-value = 0.008).conclusions:The most common predictors for Os.w.re the underlying cause of Hcc, AFP, and tumor size. Being having non-viral etiology, a tumor size >5 cm, an AFP > 400 ng/mL, and a cTP score class c were all negatively associated with Os.

关键词： Alpha-fetoprotein (AFP) child-turcotte-pugh Hepatocellular carcinoma Pattern Progression free survival

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A Novel Application of Multi-Resonant Dissipative Elastic Metahousing for Bearings

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Acta Mechanica solida sinica 2021年第4期34卷 449-465页

作者： Muhammad c.w.Lim N.s.Vyas Department of Architecture and civil Engineering City University of Hong KongKowloonHong Kong SARChina Department of Mechanical Engineering Indian Institute of Technology KanpurKanpur208016India

Bearing as an important machine element is.w.dely used for industrial and automotive *** certain operational speed,bearings induce disturbing vibrations and noises that affect machine service life,productivity and passenger comfort in case of vehicle *** elastic metamaterials have caught considerable attention of scientific community due to their effective medium properties and peculiar dynamic characteristics including frequency bandgaps that can be effectively applied to attenuate and control undesirable vibration and *** a substantial amount of theoretical work for effective medium characteristics and dynamic properties of acoustic/elastic metamaterials has been reported,the practical design and application of these composite structures for real-life engineering problems still remain *** present study intends to investigate a potential application of dissipative elastic metamaterials in controlling the bearing-generated vibration and noises over an ultrawide frequency *** study is based on a simple analytical model together with rigorous finite element numerical *** has been established that the dissipative characteristic of resonant system caused by larger material mismatch broadens the local resonance bandgaps beyond the bounding resonance frequency at the cost of wave *** order to achieve broadband vibration and noise control,multi-resonant composite structures are embedded inside the bearing housing in five different *** reported results revealed the presence of broadband wave attenuation zone distributed from 3 to 52 kHz with consideration of material *** bearing-generated vibration and noises lying inside the wave attenuation zone will be *** feasibility study provides a new concept for the design and application of acoustic/elastic metamaterials in the bearing industry to improve machine service life and to enhance productivity and passenger comfo

关键词： Bearing metahousing Dissipative elastic metamaterials Frequency Local resonance bandgap Vibration attenuation zone

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chemical characteristics of aerosols at coastal station in Hong Kong.Ⅱ. Environmental behavior of trace elements during the April 1995 to April 1996

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Journal of Environmental sciences 2004年第2期16卷 212-221页

作者： K.s.Lam Z.L.cheng s.c.Kot c.w.Tsang Department of civil and structural Engineering the Hong Kong Polytechnic UniversityResearch Center for Eco-Environmental Sciences Chinese Academy of SciencesDepartment of Mechanical Engineering The Hong Kong University of Science & Technology Clear Water BayDepartment of Applied Biology and Chemical Technology the Hong Kong Polytechnic University Hung Hom Hong Kong ChinaBeijing 100085 ChinaHong Kong ChinaHung Hom Hong Kong China

An one-year of sampling aerosol program was carried out during the period of April 1995 to April 1996 at coastal region, cape D′Aguilar, in Hong Kong. The trace element composition of aerosol particles(TsP and PM 10 ) were measured and analyzed by using the Instrumental Neutron Activation Analysis(INAA) and Inductive couple Plasma-Mass spectrometry(IcP-Ms) techniques. The results showed that the polluted elements such as: V, Zn, As, Pb, cd, sb, I, se, Bi, with high enrichment factor(E.F) values, are derived from anthropogenic sources, while sc, Al, Fe, Mn, sm, La, sr are less than 10 in E.F, these elements are related the crust and soil. The concentration of the trace elements are present seasonal variation i.e. summer low and winter high, whereas the V or noncrustal V(V *) present summer high and winter low, this phenomenon might be explained by local or regional oil combustion sources. Use three type of elemental ratio, e.g. La/sm, Mn */V * and Bi/Al indicate that both TsP and PM 10 of La/sm ratios are mainly related to soil and dust, Mn */V * are probably represent fossil combustion and Bi/Al are possibly associated with refuse incineration, ferromanganese alloys and aluminum production. The varimax rotation factor analysis for trace elements.w.s performed. By means of the absolute principal component analysis(APcA) and multiple regression, the contribution of trace elements to possible sources and overall means of trace elements.w.re estimated. The results showed that the present station is impacted by the anthropogenic species, although the quantities are different during the summertime and wintertime.

关键词： TsP PM 10 trace elements enhancement factor element ratios seasonal variation factor analysis

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Optimal selling Time in stock Market over a Finite Time Horizon

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Acta Mathematicae Applicatae sinica 2012年第3期28卷 557-570页

作者： s.c.P.YAM s.P.YUNG w.ZHOU The chinese University of Hong Kong China The University of Hong Kong China

In this paper, we examine the best time to sell a stock at a price being as close as possible to its highest price over a finite time horizon [0, T], where the stock price is modelled by a geometric Brownian motion and the ＇closeness＇ is measured by the relative error of the stock price to its highest price over [0, T]. More precisely, we want to optimize the expression：V^＊=sup 0≤τ≤T E[Vτ/MT],where （Vt）t≥0 is a geometric Drownian motion with constant drift α and constant volatility σ 〉 0, Mt = max Vs 0≤a〈t is the running maximum of the stock price, and the supremum is taken over all possible stopping times 0 ≤ τ≤T adapted to the natural filtration （Ft）t≥0 of the stock price. The above problem has been considered by shiryacv, Xu and Zhou （2008） and Du Toit and Peskir （2009）. In this paper we provide an independent proof that when α=1/ 2 σ^2 , a selling strategy is optimal if and only if it sells the stock either at the terminal time T or at the 1 2 moment when the stock price hits its maximum price so far. Besides, when α 〉1/2σ^2 , selling the stock at the terminal time T is the unique optimal selling strategy. Our approach to the problem is purely probabilistic and has been inspired by relating the notion of dominant stopping pr of a stopping time τ to the optimal stopping strategy arisen in the classical ＂secretary Problem＂.

关键词： optimal stopping stock selling buy and hold local time

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On the Variability and correlation of surface Ozone and carbon Monoxide Observed in Hong Kong Using Trajectory and Regression Analyses

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Advances in Atmospheric sciences 2004年第1期21卷 141-152页

作者：王体健 K.s.LAM c.w.TsANG s.c.KOT Department of Atmospheric sciences Nanjing University Nanjing 210093 Environmental Engineering Unit Department of Civil & Structural Engineering The Hong Kong Polytechnic University Hong Kong Environmental Engineering Unit Department of Civil & Structural Engineering The Hong Kong Polytechnic University Hong Kong Department of Mechanical Engineering Hong Kong University of Science & Technology Hong Kong

This paper investigates, the variability and correlation of surface ozone (Os) and carbon monoxide (cO) observed at cape D'Aguilar in Hong Kong from 1 January 1994 to 31 December 1995. statistical analysis shows that the average O3 and cO mixing ratios during the two years are 32±17ppbv and 305±191 ppbv, respectively. The O3/cO ratio ranges from 0.05 to 0.6 ppbv/ppbv with its frequency peaking at 0.15. The raw dataset is divided into six groups using backward trajectory and cluster analyses. For data assigned to the same trajectory type, three groups are further sorted out based on cO and NOX mixing ratios. The correlation coefficients and slopes of O3/cO for the 18 groups are calculated using linear regression analysis. Finally, five kinds of air masses.w.th different chemical features are identified: continental background (cB), marine background (MB), regional polluted continental (RPc), perturbed marine (P*M), and local polluted (LP) air masses. Further studies indicate that O3 and cO in the continental and marine background air masses (cB and MB) are positively correlated for the reason that they are well mixed over the long range transport before arriving at the site. The negative correlation between O3 and cO in air mass LP is believed to be associated with heavy anthropogenic influence, which results from the enhancement by local sources as indicated by high cO and NOx and depletion of O3 when mixed with fresh emissions. The positive correlation in the perturbed marine air mass P*M favors the low photochemical production of O3. The negative correlation found in the regional polluted continental air mass RPc is different from the observations at Oki Island in Japan due to the more complex O3 chemistry at cape D'Aguilar.

关键词： ozone carbon monoxide trajectory

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