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Metabolic activity of Streptococcus mutans biofilms and gene expression during exposure to xylitol and sucrose

International Journal of Oral Science 2014年第4期6卷 195-204页

作者： Eva-Maria Decker Christian Klein dimitri schwindt Christiane von Ohle Department for Pediatric and Operative Dentistry Periodontology and Endodontology Center of Dentistry Oral Medicine and Maxillofacial Surgery University of Tbingen Private Practice Zahngesundheit Waiblingen

The objective of the study was to analyse Streptococcus mutans biofilms grown under different dietary conditions by using multifaceted methodological approaches to gain deeper insight into the cariogenic impact of carbohydrates. S. mutans biofilms were generated during a period of 24 h in the following media： Schaedler broth as a control medium containing endogenous glucose, Schaedler broth with an additional 5% sucrose, and Schaedler broth supplemented with 1% xylitol. The confocal laser scanning microscopy（CLSM）-based analyses of the microbial vitality, respiratory activity（5-cyano-2,3-ditolyl tetrazolium chloride, CTC） and production of extracellular polysaccharides（EPS） were performed separately in the inner, middle and outer biofilm layers. In addition to the microbiological sample testing, the glucose/sucrose consumption of the biofilm bacteria was quantified, and the expression of glucosyltransferases and other biofilm-associated genes was investigated. Xylitol exposure did not inhibit the viability of S. mutans biofilms, as monitored by the following experimental parameters： culture growth, vitality, CTC activity and EPS production. However,xylitol exposure caused a difference in gene expression compared to the control. Gtf C was upregulated only in the presence of *** xylitol exposure, gtf B was upregulated by a factor of 6, while under sucrose exposure, it was upregulated by a factor of *** with glucose and xylitol, sucrose increased cell vitality in all biofilm layers. In all nutrient media, the intrinsic glucose was almost completely consumed by the cells of the S. mutans biofilm within 24 h. After 24 h of biofilm formation, the multiparametric measurements showed that xylitol in the presence of glucose caused predominantly genotypic differences but did not induce metabolic differences compared to the control. Thus, the availability of dietary carbohydrates in either a pure or combined form seems to affect the cariogenic potential of

关键词： biofilms 5-cyano-2 3-ditolyl tetrazolium chloride extracellular polysaccharides gene expression Streptococcus mutans sucrose viability xylitol

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Simulation and Performance Analysis of Six Types of Sun Tracker Approaches:A Comparative Analysis for Solar Concentrating Technology Application at Burkina Faso

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Journal of Energy and Power Engineering 2024年第1期18卷 1-8页

作者： Stanislas Sanfo Serge dimitri Bazyomo Tizane Daho Abdoulaye Ouedraogo Laboratoire de Physique et de Chimie de l’Environnement(LPCE) Departement de PhysiqueUnitéde Formation et de Recherche en Sciences Exactes et AppliquéesUniversitéJoseph KI-ZERBOOuagadougouBP 7021Burkina Faso Laboratory of Thermal and Renewable Energies Department of Physics Unit of Training and Research on Exact and Applied SciencesUniversity Joseph KI-ZERBOOuagadougouBP 7021Burkina Faso Laboratoire Recherche Développement(LARED) Universitéde OuahigouyaBurkina Faso

Modelization equations of six approaches for tracking the sun are recalled and used to evaluate the constraints and performances to which they lead *** geographical study case is taken for the specific latitude of 12 North that is a good matching with the location of the country of Burkina *** decisive periods were locally established in order to consider the different travels of the sun on sky during one *** work presents some technical data which facilitates the choice of sun tracking approaches with concern of a concentrator limits such as its angle of acceptance,its motion control card interpolation model,or its minimum irradiation level for energy conversion effectiveness.

关键词： Solar radiation sun tracker Burkina Faso experimental data

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Contribution of Satellite Observations in the Optical and Microphysical Characterization of Aerosols in Burkina Faso, West Africa

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Atmospheric and Climate Sciences 2024年第1期14卷 154-171页

作者： Nébon Bado Serge dimitri Bazyomo Germain Wende Pouiré Ouedraogo Bruno Korgo Mamadou Simina Dramé Florent P. Kieno Sié Kam Laboratoire d’Energies Thermiques Renouvelables (L.E.T.RE) Université Joseph KI ZERBO Ouaga Burkina Faso Laboratoire de Physique de l’Atmosphère et de l’Océan Siméon-Fongang Université Cheikh Anta DIOP Dakar-Fann Sénégal Institute of Mathematics and Physical Sciences University of Abomey-Calavi Porto-Novo Benin

In this work, we proceed to an optical and microphysical analysis of the observations reversed by the MODIS, SeaWiFS, MISR and OMI sensors with the aim of proposing the best-adapted airborne sensor for better monitoring of aerosols in Burkina Faso. To this end, a comparison of AOD between satellite observations and in situ measurements at the Ouagadougou site reveals an underestimation of AERONET AOD except for OMI which overestimates them. Also, an inter-comparison done based on the linear regression line representation shows the correlation between the aerosol models incorporated in the airborne sensor inversion algorithms and the aerosol population probed. This can be seen through the correlation coefficients R which are 0.84, 0.64, 0.55 and 0.054 for MODIS, SeaWiFS, MISR and OMI respectively. Furthermore, an optical analysis of aerosols in Burkina Faso by the MODIS sensor from 2001 to 2016 indicates a large spatial and temporal variability of particles strongly dominated by desert dust. This is corroborated by the annual and seasonal cycles of the AOD at 550 nm and the Angström coefficient measured in the spectral range between 412 nm and 470 nm. A zoom on a few sites chosen according to the three climatic zones confirms the majority presence of mineral aerosols in Burkina Faso, whose maxima are observed in spring and summer.

关键词： AERONET Airborne Sensors Aerosol Optical and Microphysical Properties

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Surgical Management of Lumbar Spinal Canal Stenosis with Instrumentation at the Yaounde Central Hospital: Comparison of Unilateral versus Bilateral Pedicle Screw Fixation Combined with Transforaminal Lumbar Interbody Fusion

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Open Journal of Modern Neurosurgery 2024年第3期14卷 179-189页

作者： Orlane Toto Ndome Nassourou Oumarou Haman dimitri Fogue Jean Bruno Ndoumou Ronaldo Fonju Anu Indira Baboke Vincent De Paul Djientcheu Faculty of Medicine and Pharmaceutical Sciences University of Douala Douala Cameroon Department of Neurosurgery Douala General Hospital Douala Cameroon Faculty of Medicine and Biomedical Sciences University of Yaounde 1 Yaounde Cameroon Department of Neurosurgery Yaounde General and Central Hospitals Yaounde Cameroon Cameroon Academy of Young Scientists Yaounde Cameroon

Introduction: The choice of adopting unilateral pedicle screw fixation or using bilateral pedicle screw fixation in lumbar spinal stenosis remains controversial. In our context, very few studies have been performed comparing the clinical effectiveness of unilateral versus bilateral fixation in the surgical management of lumbar spinal canal stenosis. Objective: Evaluate the impact on quality of life and clinical efficacy of unilateral spondylodesis compared to bilateral spondylodesis in the surgical management of lumbar spinal canal stenosis at the Yaounde Central Hospital. Methods: This was a retrospective descriptive cross-sectional study for a period of 4 years, from June 2015 to June 2019. It involved all patients operated for lumbar canal stenosis and who underwent spondylodesis or spinal fusion at the neurosurgery department of the Yaounde Central Hospital. Results: A total of 68 participants were recruited during our study period. 32 (47%) of the study population were in the 50 - 60 age group, with a mean age of 56.98 years ranging from 41 to 75 years. Females, housewives and farmers were the most affected. In our study, 72% of patients had unilateral spondylodesis and 28% had bilateral fusion. Preoperatively, 71% of patients had insurmountable pain, refractory to medical treatment. At 3 months postoperatively, 73.7% of patients with bilateral setup had moderate pain compared to 69% of those with unilateral setup. At 6 months postoperatively, 79% of patients with bilateral fusion had mild pain compared to 82% of patients with unilateral setup. At 1 year postoperatively, all patients had mild pain. Preoperatively, 66.2% of patients were unable to walk and 19.1% of patients were bedridden according to the Oswestry score. At 3 months postoperatively, 10.2% of patients with unilateral setup were unable to walk compared to 10.5% of patients with bilateral fixation, while 67.3% of patients with unilateral fixation had moderate disability compared to 52.6% of patient

关键词： Lumbar Spinal Canal Stenosis Instrumentation Surgery Quality of Life

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Multi-Scale Approach for Gold Targeting in Côte d’Ivoire Paleoproterozoic Rocks

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Open Journal of Geology 2024年第2期14卷 155-176页

作者： Martial Pohn Koffi Adingra Yao Augustin Koffi N’guessan Nestor Houssou Zié Ouattara Tokpa Kakeu Lionel-dimitri Boya Marc Ephrem Allialy Training and Research Unit in Earth Sciences and Mineral Resources Laboratory of Geology Mineral and Energy Resources University Felix HOUPHOU&#203T-BOIGNY Abidjan C&#244te d’Ivoire Training and Research Unit in Geological Sciences and Mining Department of Geology and Material Man University Man C&#244te d’Ivoire

The aim of this study is to contribute to better targeting of gold prospecting areas using geospatial information. To this end, 3 mining sites were selected for the study. They are: the Sénoufo belt (Barrick Gold mine), the Yaouré complex (Perseus Mining mine) and the South Fetêkro belt (Bonikro, Hiré and Agbaou mines). For this study, a multi-scale approach was carried out at regional, mine and microscopic levels. At the regional scale, a comparative analysis of 1:200,000 scale geological maps revealed that 3 main lithologies are regularly repeated on and around the various mining sites. These are: undifferentiated volcanics, metagranodiorites and metasiltites dominated by meta-arenites. Most of these lithologies are affected by undifferentiated faults generally oriented NE-SW, N-S, ENE-WSW and WNW-ESE. In addition, gold and manganese occurrences are present on all the sites studied. At the mine scale, radarsat-1 images processing indicate that the main mining sites are generally located near or at the intersection of lineaments-oriented NE-SW or N-S on the one hand and E-W or ENE-WSW or WNW-ESE or again NW-SE on the other. These mines are also located at the interface between zones of high and low lineament density. At the microscopic scale, petrographic studies of undifferentiated volcanic samples from the various sites indicate that they consist of andesites, meta-andesites and tuffs.

关键词： Gold Targeting Undifferentiated Volcanics Mineral Occurrences Lineaments Côte d’Ivoire

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Peripheral Facial Paralysis in People Living with Human Immunodeficiency Virus (HIV)

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International Journal of Otolaryngology and Head & Neck Surgery 2024年第3期13卷 168-177页

作者： Lekassa Pierrette Andjock Nkouo Yves Christian Mouinga Abayi Alex Davy Assoumou Ada Prudence BiyeNgoghe Prudence Ngoma Manfoumbi Albert Brice Manfoumbi Manfoumbi Kévin dimitri Miloundja Jerome Nzouba Léon ENT and CFS Department Omar Bongo Ondimba Army Instruction Hospital Libreville Gabon Department of Surgery and Surgical Specialties University of Health Sciences Owendo Gabon ENT and CFS Department Yaound&#233 General Hospital Yaound&#233 Cameroon Ophthalmology Department Omar Bongo Ondimba Army Instruction Hospital Libreville Gabon Ophthalmology Department Owendo University Hospital Center Libreville Gabon Internal Medicine Department Omar Bongo Ondimba Army Instruction Hospital Libreville Gabon

Introduction: Peripheral facial palsy (PFP) is a frequent reason for ENT consultations. It is a common complication of human immunodeficiency virus (HIV) infection. The aim of this study was to describe the diagnostic and therapeutic aspects and to establish the correlation between PFP and HIV in our context. Patients and Method: This was a retrospective descriptive study conducted in the ENT and CFS department of the HIAOBO, covering the medical records of patients hospitalized for taking a PFP on HIV terrain from January 1, 2016 to December 31, 2020. Results: The study involved 17 patients, 10 men (59%) and 7 women (41%), a sex ratio of 1.4. The average age was 39 years with the extremes of 11 and 69 years. Shopkeepers reported 9 cases (53%). The reason for consultation was facial asymmetry in 11 cases (100%). The delay in consultation during the first week was 82.4%. Clinical signs were unilateral facial asymmetry, the opening of the palpebral fissure and lacrimation. All patients received medical treatment for PFP and HIV. Evolution was favorable, with complete recovery and no sequelae in 82.4% of cases. Surgery was performed in one case. Conclusion: PFPs are common in HIV infection. Diagnosis is clinical and management is multidisciplinary. Progression depends on the length of time taken to treat the disease.

关键词： Peripheral Facial Paralysis HIV HIAOBO

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Carbon dioxide desorption behavior of potassium carbonate supported on gamma-alumina solid sorbent in wet fluidized bed under steam atmosphere

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Particuology 2023年第10期81卷 15-24页

作者： Sasitron Angkanawisan dimitri Gidaspow Pornpote Piumsomboon Benjapon Chalermsinsuwan Fuels Research Center Department of Chemical TechnologyFaculty of ScienceChulalongkorn University254 Phayathai RoadPathumwanBangkok10330Thailand Center of Excellence on Petrochemical and Materials Technology Chulalongkorn University254 Phayathai RoadPathumwanBangkok10330Thailand Department of Chemical and Biological Engineering Armour College of EngineeringIllinois Institute of Technology10 West 35th StreetChicagoIL60616United States Advanced Computational Fluid Dynamics Research Unit Chulalongkorn University254 Phayathai RoadPathumwanBangkok10330Thailand

Since the carbon dioxide(CO_(2))capture using solid sorbent is a reversible reaction,the solid sorbent can be regenerated by the desorption ***,the desorption process is one of the key important processes for the CO_(2)capture ***,most of the literature studies focus on the desorption of solid sorbent under an N_(2)***,the desorption process of the solid sorbent is inappropriate in the real system because the system will need another process to separate CO_(2)and nitrogen(N_(2))after the desorption *** study focused on the CO_(2)desorption of potassium carbonate supported on gamma-alumina(K2CO3/γ-Al_(2)O_(3))in a wet fluidized bed under a steam atmosphere by using the multiphase computational fluid dynamics(CFD)*** effects of water thickness and dry restitution coefficient on CO_(2)desorption rate were investigated to provide a realistic particle collision behavior and to explore their effects on CO_(2)desorption ***,the effect of steam velocity on the hydrodynamic behaviors of fluidization which on CO_(2)desorption rate was *** simulated results demonstrated that all the parameters,water thickness,dry restitution coefficient,and steam velocity had significantly affected system hydrodynamics and CO_(2)desorption rate in the wet fluidization desorption ***,the effect of desorption temperature on CO_(2)desorption rate was evaluated for finding the appropriate temperature for CO_(2)desorption process of K2CO3/γ-Al_(2)O_(3).The results showed that the appropriate desorption temperature for CO_(2)desorption under steam atmosphere was the temperature over 150℃.

关键词： CO_(2)desorption Fluidized bed K_(2)CO_(3)/Y-Al_(2)O_(3) Restitution coefficient Wet fluidization Computational fluid dynamics

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Static Analysis of Doubly-Curved Shell Structures of Smart Materials and Arbitrary Shape Subjected to General Loads Employing Higher Order Theories and Generalized Differential Quadrature Method

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Computer Modeling in Engineering & Sciences 2022年第12期133卷 719-798页

作者： Francesco Tornabene Matteo Viscoti Rossana dimitri Department of Innovation Engineering School of EngineeringUniversity of SalentoLecce73100Italy

The article proposes an Equivalent Single Layer(ESL)formulation for the linear static analysis of arbitrarily-shaped shell structures subjected to general surface loads and boundary conditions.A parametrization of the physical domain is provided by employing a set of curvilinear principal *** generalized blendingmethodology accounts for a distortion of the structure so that disparate geometries can be *** layer of the stacking sequence has an arbitrary orientation and is modelled as a generally anisotropic *** addition,re-entrant auxetic three-dimensional honeycomb cells with soft-core behaviour are considered in the *** unknown variables are described employing a generalized displacement field and pre-determined through-the-thickness functions assessed in a unified ***,a weak assessment of the structural problem accounts for shape functions defined with an isogeometric approach starting fromthe computational *** has been proposed to define two-dimensional distributions of static surface *** the same way,boundary conditions with three-dimensional features are implemented along the shell edges employing linear *** fundamental relations are obtained from the stationary configuration of the total potential energy,and they are numerically tackled by employing the Generalized Differential Quadrature(GDQ)method,accounting for nonuniform computational *** the post-processing stage,an equilibrium-based recovery procedure allows the determination of the three-dimensional dispersion of the kinematic and static *** case studies have been presented,and a successful benchmark of different structural responses has been performed with respect to various refined theories.

关键词： 3D honeycomb anisotropic materials differential quadrature method general loads and constraints higher order theories linear static analysis weak formulation

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Static Analysis of Anisotropic Doubly-Curved Shell Subjected to Concentrated Loads Employing Higher Order Layer-Wise Theories

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Computer Modeling in Engineering & Sciences 2023年第2期134卷 1393-1468页

作者： Francesco Tornabene Matteo Viscoti Rossana dimitri Department of Innovation Engineering School of EngineeringUniversity of SalentoLecce73100Italy

In the presentmanuscript,a Layer-Wise(LW)generalizedmodel is proposed for the linear static analysis of doublycurved shells constrained with general boundary conditions under the influence of concentrated and surface *** unknown field variable is modelled employing polynomials of various orders,each of them defined within each layer of the *** a particular case of the LW model,an Equivalent Single Layer(ESL)formulation is derived *** approaches are outlined for the assessment of external forces,as well as for non-conventional *** doubly-curved shell is composed by superimposed generally anisotropic laminae,each of them characterized by an arbitrary *** fundamental governing equations are derived starting from an orthogonal set of principal ***,generalized blending functions account for the distortion of the physical *** implementation of the fundamental governing equations is performed bymeans of the Generalized Differential Quadrature(GDQ)method,whereas the numerical integrations are computed employing theGeneralized IntegralQuadrature(GIQ)*** the post-processing phase,an effective procedure is adopted for the reconstruction of stress and strain through-the-thickness distributions based on the exact fulfillment of three-dimensional equilibrium equations.A series of systematic investigations are performed in which the static response of structures with various curvatures and lamination schemes,calculated by the present methodology,have been successfully compared to those ones obtained fromrefined finite element three-dimensional *** though the present LW approach accounts for a two-dimensional assessment of the structural problem,it is capable of well predicting the three-dimensional response of structures with different characteristics,taking into account a reduced computational cost and pretending to be a valid alternative to widespread numerical implementations.

关键词： Concentrated load doubly-curved shells generalized differential quadrature laminated anisotropic materials layer-wise theory mapping technique

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Pilfering of western juniper seed caches by scatter-hoarding rodents varies by microsite and canopy type

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Integrative Zoology 2022年第2期17卷 192-205页

作者： Lindsay A.dimitri William S.LONGLAND Agricultural Research Service Great Basin Rangeland ResearchUSDAUSA

Scatter-hoarding rodents store seeds throughout their home ranges in superficially buried caches which,unlike seeds larder-hoarded in burrows,are difficult to *** seeds are often pilfered by other scatter-hoarders and either re-cached,eaten or *** seed movements can influence seedling recruitment,because only seeds remaining in caches are likely to *** the importance of scatter-hoarding rodents in the dispersal of western juniper seeds has recently been revealed,the level of pilfering that occurs after initial burial is *** traits,soil moisture,and substrate can influence pilfering processes,but less is known about how pilfering varies among caches placed in open versus canopy microsites,or how cache discovery and removal varies among different canopy-types,tree versus *** compared the removal of artificial caches between open and canopy microsites and between tree and shrub canopies at two sites in northeastern California during late spring and *** also used trail cameras at one site to monitor artificial cache removal,identify potential pilferers,and illuminate microsite use by *** of artificial caches was faster in open microsites at both sites during both seasons,and more caches were removed from shrub than tree *** kangaroo rats were the species observed most on cameras,foraging most often in open microsites,which could explain the observed pilfering *** is the first study to document pilfering of western juniper seeds,providing further evidence of the importance of scatter-hoarding rodent foraging behavior in understanding seedling recruitment processes in juniper woodlands.

关键词： Dipodomys californicus Juniperus Perognathus parvus Peromyscus truei seed caching seed dispersal

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