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HOMOGENIZATION RESULTS FOR ENZYME CATALYZED REACTIONS THROUGH POROUS MEDIA

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Acta Mathematica Scientia 2009年第1期29卷 74-82页

作者： Claudia timofte Department of Mathematics Faculty of Physics University of BucharestP.O. Box MG-11

The aim of this article is to study the effective behavior of the solution of a nonlinear problem arising in the modelling of enzyme catalyzed reactions through the exterior of a domain containing periodically distributed reactive solid obstacles,with period ε.The asymptotic behavior of the solution of such a problem is governed by a new elliptic boundary-value problem,with an extra zero-order term that captures the effect of the enzymatic reactions.

关键词： Homogenization enzyme reactive flows Michaelis-Menten mechanism

A semiclassical perspective on nuclear chirality

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Frontiers of physics 2024年第2期19卷 39-52页

作者： radu Budaca “Horia Hulubei”National Institute for R&D in Physics and Nuclear Engineering Str.Reactorului 30RO-077125POB-MG6 Bucharest-MǎgureleRomania Academy of Romanian Scientists Splaiul Independenţei 54050044BucharestRomania

The application of the semiclassical description to a particle-core system with imbued chiral symmetry is *** classical features of the chiral geometry in atomic nuclei and the associated dynamics are investigated for various core deformations and single-particle *** dynamical characteristics are identified in specific angular momentum ranges,triaxiality and alignment *** observables will be extracted from the classical picture for a quantitative description of experimental data provided as numerical examples of the model’s performance.

关键词： chiral symmetry triaxial nuclei semiclassical description

Evaluation of the seismic hazard for 20 cities in Romania using Monte Carlo based simulations

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Earthquake Engineering and Engineering Vibration 2017年第3期16卷 513-523页

作者： Florin Pavel radu Vacareanu Seismic Risk Assessment Research Center Technical University of Civil Engineering Bucharest Romania

This work focuses on the evaluation of the seismic hazard for Romania using earthquake catalogues generated by a Monte Carlo approach. The seismicity of Romania can be attributed to the Vrancea intermediate-depth seismic source and to 13 other crustal seismic sources. The recurrence times of large magnitude seismic events（both crustal and subcrustal）, as well as the moment release rates are computed using simulated earthquake catalogues. The results show that the largest contribution to the overall moment release for the crustal seismic sources is from the seismic regions in Bulgaria, while the seismic regions in Romania contribute less than 5% of the overall moment release. In addition, the computations show that the moment release rate for the Vrancea subcrustal seismic source is about ten times larger than that of all the crustal seismic sources. Finally, the Monte Carlo approach is used to evaluate the seismic hazard for 20 cities in Romania with populations larger than 100,000 inhabitants. The results show some differences between the seismic hazard values obtained through Monte-Carlo simulation and those in the Romanian seismic design code P100-1/2013, notably for cities situated in the western part of Romania that are influenced by local crustal seismic sources.

关键词： seismic sources uncertainty seismic moment GMPE percentile

Investigation on regional attenuation of Vrancea (Romania) intermediate-depth earthquakes

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Earthquake Engineering and Engineering Vibration 2018年第3期17卷 501-509页

作者： Florin Pavel radu Vacareanu Seismic Risk Assessment Research Center Technical University of Civil Engineering

This paper aims at investigating possible regional attenuation patterns in the case of Vrancea（Romania） intermediate-depth *** 500 pairs of horizontal components recorded during 13 intermediate-depth Vrancea earthquakes are employed in order to evaluate the regional attenuation *** recordings are grouped according to the azimuth with regard to the Vrancea seismic source and subsequently,Q models are computed for each azimuthal zone assuming similar geometrical ***,the local soil amplification which was disregarded in a previous analysis performed for Vrancea intermediate-depth earthquakes is now clearly *** results show minor differences between the four regions situated in front of the Carpathian Mountains and considerable differences in attenuation of seismic waves between the forearc and backarc regions（with regard to the Carpathian Mountains）.Consequently,an average Q model of the type Q（f） = 115×f^1.25 is obtained for the four forearc regions,while a separate Q model of the type Q（f） = 70×f^0.90 is computed for the backarc *** results highlight the need to evaluate the seismic hazard of Romania by using ground motion models which take into account the different attenuation between the forearc/backarc regions.

关键词： Fourier amplitude spectrum azimuth dependency source-to-site distance Q model local soil conditions

Autologous cord blood vs individualized supplements in autistic spectrum disorder:CORDUS study results

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World Journal of Clinical Pediatrics 2025年第1期14卷 101-112页

作者： Felician A Stancioiu Raluca Bogdan Bogdan Ivanescu radu Dumitrescu Department of Clinical Research Bio-Forum FoundationBucharest 040245BucurestiRomania Department of Pediatrics Medicover Hospital BucharestBucharest 013982BucurestiRomania Doctor MiT Clinic Bucharest 013929BucurestiRomania Department of Anesthesiology and Intensive Therapy Medicover HospitalBucharest 013982BucurestiRomania

BACKGROUND Cellular therapies have started an important new therapeutic direction in autistic spectrum disorder(ASD),and the ample diversity of ASD pathophysiology and the different types of cell therapies prompt an equally ample effort to employ clinical studies for studying the ASD causes and cell *** cells have yielded so far mixed results in clinical trials,and at patient level the results varied from impressive to no *** this context we have administered autologous cord blood(ACB)and a non-placebo,material intervention repre-sented by an individualized combination of supplements(ICS)to ASD *** CORDUS clinical study is a crossover study in which both oral ICS and intravenous ACB were sequentially administered to 56 children;ACB was infused as an inpatient *** efficacy was evaluated pre-treatment and post-treatment at 6 months by an independent psychotherapist with Autism Treatment Evaluation Checklist,Quantitative Checklist for Autism in Toddlers and a 16-item comparative table score,after interviewing the children’s parents and *** and after each intervention participants had a set of blood tests including inflammatory,metabolic and oxidative markers,and the neuronal specific *** No serious adverse reactions were noted during and after cord blood or supplement *** improved evaluation scores in 78%of children with age 3–7-years(n=28),but was much less effective in kids older than 8 years or with body weight of more than 35 kg(n=28;only 11%of children improved scores).ICS yielded better results than ACB in 5 cases out of 28,while in 23 kids ACB brought more improvement than ICS(P<0.05);high initial levels of inflammation and ferritin were associated with no *** individual differences were noted in children's progress,and statistically significant improvements were seen after ACB on areas such as verbalization and social interaction,but not on irritability or

关键词： Autistic spectrum disorder Cord blood Stem cells Neuroinflammation Autologous stem cell treatment Neuronal specific enolase

Expectation-maximisation for speech source separation using convolutive transfer function

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CAAI Transactions on Intelligence Technology 2019年第1期4卷 47-53页

作者： Xiaofei Li Laurent Girin radu Horaud INRIA Grenoble Rhoe-Alpes Montbonnot Saint-MartinFrance GIPSA-lab Saint-Martin d’HèresFrance UniversitéGrenoble Alpes Saint-Martin d’HèresFrance

This study addresses the problem of under-determined speech source separation from multichannel microphone signals,*** convolutive mixtures of multiple *** time-domain signals are first transformed to the short-time Fourier transform(STFT)*** represent the room filters in the STFT domain,instead of the widely used narrowband assumption,the authors propose to use a more accurate model,*** convolutive transfer function(CTF).At each frequency band,the CTF coefficients of the mixing filters and the STFT coefficients of the sources are jointly estimated by maximising the likelihood of the microphone signals,which is resolved by an expectation-maximisation *** show that the proposed method provides very satisfactory performance under highly reverberant environments.

关键词： STFT CTF

Learning tasks as a possible treatment for DNA lesions induced by oxidative stress in hippocampal neurons

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Neural Regeneration Research 2013年第32期8卷 3063-3070页

作者： Dragos Cīrneci radu Silaghi-Dumitrescu Brain Research Institute Synergon Consulting Faculty of Chemistry and Chemical Engineering Babes-Bolyai University

Reactive oxygen species have been implicated in conditions ranging from cardiovascular dysfunc- tion, arthritis, cancer, to aging and age-related disorders. The organism developed several path- ways to counteract these effects, with base excision repair being responsible for repairing one of the major base lesions （8-oxoG） in all organisms. Epidemiological evidence suggests that cognitive stimulation makes the brain more resilient to damage or degeneration. Recent studies have linked enriched environment to reduction of oxidative stressin neurons of mice with Alzheimer＇s dis- ease-like disease, but given its complexity it is not clear what specific aspect of enriched environ- ment has therapeutic effects. Studies from molecular biology have shown that the protein p300, which is a transcription co-activator required for consolidation of memories during specific learning tasks, is at the same time involved in DNA replication and repair, playing a central role in the long-patch pathway of base excision repair. Based on the evidence, we propose that learning tasks such as novel object recognition could be tested as possible methods of base excision repair fa- cilitation, hence inducing DNA repair in the hippocampal neurons. If this method proves to be effec- tive, it could be the start for designing similar tasks for humans, as a behavioral therapeutic com- plement to the classical drug-based therapy in treating neurodegenerative disorders.

关键词： neural regeneration reviews neurodegenerative disorder reactive oxygen species base excisionrepair cognitive stimulation p300 grants-supported paper neural regeneration

Bi-normalized response spectra and seismic intensity in Bucharest for 1986 and 1990 Vrancea seismic events

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Earthquake Engineering and Engineering Vibration 2014年第1期13卷 125-135页

作者： Florin Pavel radu Vacareanu Cristian Neagu Andrei Pricopie Department of Reinforced Concrete Structures Technical University of Civil Engineering BucharestRomania Department of Strength of Materials Bridges and TunnelsTechnical University of Civil Engineering BucharestRomania

The Vrancea subcrustal earthquakes of August 30,1986 and May 30,1990 are the two most recent seismic events that have occurred in Romania with moment magnitudes M W ≥ *** spectral analysis of the strong ground motions recorded in Bucharest reveals that despite small differences in magnitude between the 1986 and 1990 earthquakes,their frequency contents are very different,sometimes even *** main focus of this study is to conduct a comparative analysis of the response spectra in terms of the bi-normalized response spectra(BNRS) proposed by Xu and Xie(2004 and 2007) for strong ground motions recorded in Bucharest during these two seismic *** mean absolute acceleration and relative velocity response spectra for the two earthquakes are discussed and ***,the mean bi-normalized absolute acceleration and normalized relative velocity response spectra with respect to the control period T C are computed for the ground motions recorded in Bucharest in 1986 and *** predominant period T P is also used in this study for the normalization of the spectral period ***,the methodology proposed by Martinez-Perreira and Bommer(1998) is applied in order to estimate the seismic intensity of the two *** results are discussed and several conclusions regarding the possibility of using the bi-normalized response spectra(BNRS) are given.

关键词： response spectra bi-normalized response spectra dynamic amplifi cation factor control period damage potential parameters

An experimental investigation of properties of polyethylene reinforced with Al powders

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第8期12卷 583-592页

作者： Victoria CHIFOR Zafer TEKINER Mehmet TURKER radu ORBAN Department of Materials Science and Technology Faculty of Materials Science and EngineeringTechnical University of Cluj-Napoca Mechanical/Metallurgy Education Department Faculty of Technical EducationGazi University

Mechanical and physical properties, such as tensile strength, elongation at break, modulus of elasticity, Shore D hardness, melt flow rate (MFR), and electrical and thermal conductivities of composites with high density polyethylene matrix reinforced with Al powders were investigated experimentally. Measurements of the mechanical and physical properties were performed up to a reinforcing component concentration of 30% volume Al powder and compared with mathematical models from the literature. The obtained results have shown that experimental data were in good agreement with theoretical data. The ultimate tensile strength (UTS) and elongation at break decreased with increasing Al powder content, which was attributed to the intro-duction of discontinuities in the polymer structure, and modulus of elasticity increased with increasing Al content. The composite preparation conditions allowed the formation of a random distribution of metallic particles in the polymer matrix volume for system high density polyethylene-Al (HDPE-Al). There was a cluster formation of Al particles at higher Al contents in the polymer matrix. Electrical and thermal conductivity values of HDPE-Al composites were higher than pure HDPE values.

关键词： Polymer composite Mechanical properties Melt flow rate(MFR) Thermal conductivity Electrical conductivity