Inducing neuronal regeneration and differentiation via the BDNF/ TrkB signaling pathway: a key target against neurodegenerative diseases?

Brain-derived neurotrophic factor(BDNF)is one of the neurotrophins,a specific polypeptide growth factor,which plays a crucial role in the proliferation,differentiation,survival,and death of neurons and non-neuronal cells.It is not only essential to maintain the balance between death on one side and survival of neurons on the other,but also it mediates additional higher-order activities such as learning,memory,and behavior.It is initially synthesized as a precursor protein,proBDNF,that can be secreted as it is or it can be cleaved intracellularly by furin and proconvertases,or extracellularly by extracellular proteases such as matrix metalloprotease-9 and matrix metalloprotease-2,or plasmin to give mature BDNF.

The Interactions Between“Business”Culture,“Professional”Culture and Training

Ultimately,the fundamental issues of educational sciences remain economic and societal.The interactions between“business”culture,“professional”culture and training are part of this.This contribution is a reflection resulting from a longitudinal empirical research entitled:“Professionalization of an establishment in the social and medico-social field:a French monograph after the law 2002-02 of January 02,2002”.Three concepts were used:“making sense”(Weick,1995);the“strategic paradigm”(Jonhson,1987);and“cultures of action”(Sorel&Wittorski,2005;Barbier,2010;Ardouin,2015).

Magnesium sulfate and fetal neuroprotection: overview of clinical evidence

Antenatal administration of magnesium sulfate is an important part of the neuroprotective strategy for preterm infants. Strong evidence from five randomized controlled trials and five meta-analyses has demonstrated that magnesium sulfate, when administered before preterm delivery, significantly reduces the risk of cerebral palsy at two years. Through secondary analyses of randomized controlled trials and other original clinical studies, this state-of-the-art review highlights the absence of serious adverse effects in both pregnant women and neonates, as well as the impact of maternal body mass index and preeclamptic status on the maternal and neonatal magnesium levels, which could influence the magnitude of the neuroprotective effect. Although antenatal magnesium sulfate is a cost-effective strategy, some practice surveys have demonstrated that the use of magnesium sulfate is not sufficient and that its use is heterogeneous, differing among different maternity wards. Since 2010, an increasing number of obstetrical societies have recommended its use to improve the neurological outcomes of preterm infants, especially the International Federation of Gynecology and Obstetrics and World Health Organization in 2015, and France in 2017. Considering the neuroprotective impact of magnesium sulfate when administered before delivery, postnatal administration should be considered, and its effects should be assessed using randomized controlled trials.

A new piecewise linear Chen system of fractional-order:Numerical approximation of stable attractors

In this paper we present a new version of Chen＇s system： a piecewise linear （PWL） Chert system of fractional-order. Via a sigmoid-like function, the discontinuous system is transformed into a continuous system. By numerical simulations, we reveal chaotic behaviors and also multistability, i.e., the existence of small pararheter windows where, for some fixed bifurcation parameter and depending on initial conditions, coexistence of stable attractors and chaotic attractors is possible. Moreover, we show that by using an algorithm to switch the bifurcation parameter, the stable attractors can be numerically approximated.

Achieving an optimal shock-wave mitigation inside open channels with cavities for weak shock waves:A computational study

This paper deals with a numerical study of weak shock-waves propagation and their attenuation in channel flow having different heights and exhibiting a hollow circular cavities with different depths and diffraction angles inside.The effect of initial diffraction angle and cavity depth on the shock mitigation is investigated.A better shock attenuation is achieved with diffraction angle by a factor of approximately 17%in terms of shock-Mach number and 38%in terms of total energy.The obtained results show also,in addition to the initial diffraction angle and cavity depth,the importance of reducing the channel heights as well as the position of the reduced section in achieving an optimal shock-wave attenuation.The presence of a cavity inside the channel helps to attenuate faster the shock wave.The underlying physics relies on the shock diffraction phenomenon that generates large amount of vortical structures capable of dissipating part of the shock energy by inducing a pressure loss behind it.A subtle arrangement of channel position/height and a cavity location leads to an efficient pressure attenuation by approximately a factor of 57%forMs=1.6 and 16%for Ms=1.1..

The Mechanical and Crystallographic Evolution of Stipa tenacissima Leaves During In-Soil Biodegradation

The in-soil biodegradation of Stipa tenacissima(alfa)leaves was examined.Non-linear mechanical testing was performed at various biodegradation stages.Tensile strength,loading and unloading Young’s moduli and dissipation energy decreased with the burial time,whereas plasticity increased.Field-emission scanning electron microscopy(FE-SEM)showed that the fracture cracks propagated in the longitudinal direction in the raw material,resulting in a fracture mode consisting of a mixture of middle lamella delamination and fiber pull-out.In contrast,the cracks were perpendicular to the stem axis in the biodegraded material,demonstrating an important strength loss of the load-bearing fibers.This strength loss was correlated with rapid cellulose degradation.A novel X-ray diffraction(XRD)model was implemented in order to take into account anisotropic size broadening.For the first time,XRD demonstrated the action of biodegradation on unrefined plant tissues under quasi in-situ conditions.Biodegradation induced a progressive loss of crystalline cellulose accompanied with anisotropic crystallite thinning.

Physicochemical and Mechanical Performances of Technical Flax Fibers and Biobased Composite Material: Effects of Flax Transformation Process

In France,the use of flax fibers as reinforcement in composite materials is growing exponentially in the automotive sector,thanks to their good physicochemical properties,environmental reasons,health neutrality and due to the European Council Directives on the reuse,recycling and valorization of car components and materials.The aim of our study is to investigate biochemical,physicochemical,and mechanical properties of technical flax fibers to evaluate the impact of transformation processes(scutching,hackling,and homogenization)on final properties of associated composite materials.Different chemical analysis such as Van Soest(biochemical fraction measurement),FTIR(Fourier Transform InfraRed spectroscopy),and XRD(X-ray diffraction)were carried out on different process modalities and show that there is no significant difference in terms of biochemical fraction and crystallinity index.By the same token,mechanical behavior shows that Young’s modulus is not affected by the transformation process.This result is also observed for thermal behavior.The results highlight the fact that the transformation processes of technical fibers do not really affect their physicochemical and mechanical performances.

A Novel Technique for Evaluating Failure Probability of Random Structure

The purpose of this article is to develop a new methodology to evaluate the statistical characteristic of the response of structures subjecting to random excitation, by combining the Finite Element Method (FEM) with the Transforming Density Function (TDF). Uncertainty modeling of structure with random variables encourages the coupling of advanced TDF for reliability analysis to analyze problems of stochastic mechanical systems. The TDF is enthusiastically applicable in the situation where the relationship between input and output of structures is available in explicit analytical form. However, the situation is much more involved when it is necessary to perform the evaluation of implicit expression between input and output of structures through numerical models. For this aim, we propose a new technique that combines the FEM software, and the TDF method to evaluate the most important statistical parameter the Probability Density Function (PDF) of the response where the expression between input and output of structures is implicit. Once the PDF is evaluated, all other statistical parameters are derived easily. This technique is based on the numerical simulations of the FEM and the TDF by making a middleware between Finite Element software and Matlab. Some problems, range from simple to complex, of structures are analyzed using our proposed technique. Its accuracy is validated through Monte-Carlo simulation.

星形胶质细胞对脑血管功能的调控

星形胶质细胞是脑内神经胶质细胞中数量最多的一种类型,对脑血管系统具有重要的影响。它们参与调控血管周围内稳态、血脑屏障的完整性、与外周免疫系统的交流、血液中代谢物的转移以及与神经元活动相应的血管收缩。这些调控过程发生在由血管周围星形胶质细胞突起组成的几乎完全覆盖了脑血管特殊界面中。科学家直到最近才开始研究这种界面的形成方式及其如何影响脑血管功能。本文综述了有关星形胶质细胞在调节脑血管系统中作用的文献。涵盖了胶质血管界面的解剖结构和发育、已知的胶质血管功能和分子因素、后者在某些病理生理情况下的作用以及最近开发的用于检验星形胶质细胞在血管界面作用的尖端实验工具。最后,本综述重点介绍了该研究领域中的一些尚未解决的问题。

Effect of injection angle,density ratio,and viscosity on droplet formation in a microfluidic T-junction

The T-junction microchannel device makes available a sharp edge to form micro-droplets from biomaterial solutions. This article investigates the effects of injection angle, flow rate ratio, density ratio,viscosity ratio, contact angle, and slip length in the process of formation of uniform droplets in microfluidic T-junctions. The governing equations were solved by the commercial software. The results show that contact angle, slip length, and injection angles near the perpendicular and parallel conditions have an increasing effect on the diameter of generated droplets, while flow rate, density and viscosity ratios, and other injection angles had a decreasing effect on the diameter.

Zeolites for the environment

Zeolites are characterized by their microporous,crystalline structures with a four-connected framework with variable compositions,predominantly aluminosilicates.They are extensively utilized as adsorbents,catalysts,and ion exchangers across domestic and industrial sectors.With the ongoing energy transition from fossil fuels to renewable sources and the pursuit of environmentally sustainable development,zeolites are increasingly being explored beyond their traditional application fields.They are investigated for their adsorption and catalytic capabilities in the protection and restoration of air,water,and soil quality,as well as in the environmentally friendly“green”production of chemicals.This review article details these novel and potential applications of zeolites,emphasizing the unique properties that render them suitable for each specific use case and discussing how these properties can be fine-tuned through material selection or tailored synthesis methods.

Separation,speciation and quantification of both chromium(Ⅵ)and chromium(Ⅲ)in tanned leather samples:a comparative study and validation of analytical methods

In the present work,a comparative study of analytical methods for the simultaneous and quantitative determination of trivalent and hexavalent chromium is presented.For the analysis by ion chromatography-inductively coupled plasma-mass spectrometry,two different columns were tested,as well as different mobile phases and different pH of the samples.The optimized analytical method permitted the separation of Cr(Ⅲ)and Cr(Ⅵ)using 75 mmol/L NH_(4)NO_(3)pH 3 as chromatographic eluent.The method was validated and applied to real samples,allowing the determination of both species simultaneously,even when there is a huge difference of concentration between Cr(Ⅲ)and Cr(Ⅵ).Limit of detection and limit of quantification for Cr(Ⅲ)were found to be 0.016 and 0.054μg/L(0.3 and 1.1μg/kg),respectively,and for Cr(Ⅵ)0.13 and 0.43μg/L(7 and 22μg/kg),respectively.Possible species interconversions were monitored through the use of chromium isotopic standards,which confirmed that the optimized methodology preserves chromium speciation during extraction and analysis.Fourier-transform ion cyclotron resonance-mass spectrometry permitted the structure elucidation of the complex formed during ethylenediaminetetraacetic acid extraction.

Phonon engineering significantly reducing thermal conductivity of thermoelectric materials: a review

Lattice thermal conductivity, κL, is a fundamental parameter for evaluating the performance of thermoelectric materials. However, the predicted value of κL based on the Debye dispersion model is often overestimated compared with the experimentally determined value.Many researchers have attempted to modify the theoretical model and have sought more reliable results. In this review,the recent progress in the study of phonon dispersion models is summarized and we propose that the lattice thermal conductivity can be most accurately determined by using the modified sinusoidal phonon dispersion model.Moreover, experimental methods that have the potential to reduce a thermoelectric material's κLare reviewed, for example, methods that generate standing waves or anharmonic lattice vibrations. A high concentration of standing waves and anharmonic lattice vibrations can effectively suppress excessive κL. Finally, this review presents the challenges of sinusoidal phonon dispersion when applied to real materials, which are often complicated and therefore time-consuming, especially when dealing with material defects.

Adaptive neural network observer for proton-exchange membrane fuel cell system

This paper develops an adaptive neural network(NN)observer for proton-exchange membrane fuel cells(PEMFCs).Indeed,information on the oxygen excess ratio(OER)value is crucial to ensure optimal management of the durability and reliability of the PEMFC.The OER indicator is computed from the mass of oxygen and nitrogen inside the PEMFC cathode.Unfortunately,the measurement process of both these masses is difficult and costly.To solve this problem,the design of a PEMFC state observer is attractive.However,the behaviour of the fuel cell system is highly non-linear and its modelling is complex.Due to this constraint,a multilayer perceptron neural network(MLPNN)-based observer is proposed in this paper to estimate the oxygen and nitrogen masses.One notable advantage of the suggested MLPNN observer is that it does not require a database to train the NN.Indeed,the weights of the NN are updated in real time using the output error.In addition,the observer parameters,namely the learning rate and the damping factor,are online adapted using the optimization tools of extremum seeking.Moreover,the proposed observer stability analysis is performed using the Lyapunov theory.The observer performances are validated by simulation under MATLAB®/Simulink®.The supremacy of the proposed adaptive MLPNN observer is highlighted by comparison with a fixed-parameter MLPNN observer and a classical high-gain observer(HGO).The mean rela-tive error value of the excess oxygen rate is considered the performance index,which is equal to 1.01%for an adaptive MLPNN and 3.95%and 9.95%for a fixed MLPNN and HGO,respectively.Finally,a robustness test of the proposed observer with respect to measurement noise is performed.

Zeolitic germanosilicate analogue to pharmacosiderite crystallized in an acidic medium

Zeolites are typically synthesized in alkaline or fluoride-containing near-neutral media.Sophisticated organic structure-directing agents have been investigated for such systems with the aim of discovering materials with unprecedented structures and properties for novel technical applications.In contrast,zeolite crystallization in strongly acidic media has yet to be explored.This study demonstrates that a zeolitic silicate phase crystallizes from acidic gels using trimethylamine as an organic additive with the composition 1 SiO_(2):0.3 TMA:0.3 HCl:0.15 HF:55 H_(2)O:(0.1-0.4)GeO_(2).This phase has an interrupted four-connected framework analog to the octahedron/tetrahedron-mixed framework of the mineral family pharmacosiderite.In comparison to the pharmacosiderite-type HK_(3)(Ge_(7)O_(16))(H_(2)O)_(4),the four GeO_(6)-octahedra forming the central[HGe_(4)O_(4)O_(12)]-cluster are replaced by four SiO_(4)-tetrahedra in a[Si_(4)O_(6)(OH)2.89]-unit in the new phase.However,the structure is distorted and may contain connectivity and point defects;thus,healing by the occasional incorporation of GeO_(6)-units is necessary.The refined unit cell has a cubic symmetry,space group P-43m(#215),with a=7.7005(1)Å.Acidic-medium synthesis is a useful way to find new zeolites that move in a fundamentally different direction from sophisticated organic structure-directing agents.

Green Carbon:Towards a greener world

Carbon is an essential element for human survival and development.Humans,animals and plants,clothing,food,shelter,and transportation are all based on carbon.In the past hundred years,the exploitation of fossil fuels,such as coal,petroleum,and natural gas,have greatly im-proved the efficiency of industrial processes and directly advanced the progress of human civilization.At the same time,the continuously in-creasing emissions of greenhouse gases such as CO_(2) have disrupted the carbon balance established on Earth for over more than four billion years.This has led to global warming and an energy crisis with cata-strophic consequences.During the 21st century,green and low-carbon production and lifestyle have become a universal aim and provoked action around the world.

State-of-the-Art in Electrophilic Trifluoromethylthiolation Reagents

The trifluoromethylthio group （SCF3） is a fluorine chemotype that has experienced a strong acceleration of in- terest in the recent years. It is particularly true of the construction of new fluorinated architectures by electrophilic trifluoromethylthiolation. The spread of knowledge was already very active in this research domain in the sixties; however, gaseous and highly toxic trifluoromethanesulfenyl chloride （CF3SC1） was the only reagent available at that time. Nowadays, one really can speak of a revival in the field thanks to the rapid development of a wide pano- ply of reagents that are stable and easy to handle. This review provides a historical perspective of the development of shelf-stable electrophilic trifluoromethylthiolation reagents.

Fixed-time Distributed Voltage and Reactive Power Compensation of Islanded Microgrids Using Sliding-mode and Multi-agent Consensus Design

This paper investigates a fixed-time distributed voltage and reactive power compensation of islanded microgrids using sliding-mode and multi-agent consensus design.A distributed sliding-mode control protocol is proposed to ensure voltage regulation and reference tracking before the desired preset fixed-time despite the unknown disturbances.Accurate reactive power sharings among distributed generators are maintained.The secondary controller is synthesized without the knowledge of any parameter of the microgrid.It is implemented using a sparse one-way communication network modeled as a directed graph.A comparative simulation study is conducted to highlight the performance of the proposed control strategy in comparison with finite-time and asymptotic control systems with load power variations.