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Spinal cord injury-induced cognitive impairment: a narrative review

Neural Regeneration Research 2022年第12期17卷 2649-2654页

作者： oscar v.alcántar-garibay Diego Incontri-Abraham Antonio Ibarra Centro de Investigación en Ciencias de la Salud(CICSA) Facultad de Ciencias de la SaludUniversidad Anáhuac México Campus NorteHuixquilucanEstado de MéxicoMéxico

Spinal cord injury is a serious damage to the spinal cord that can lead to life-long *** on its etiology,spinal cord injury can be classified as traumatic or non-traumatic spinal cord ***,the pathology of spinal cord injury can be divided into two phases,a primary injury phase,and a secondary injury *** primary spinal cord injury phase involves the initial mechanical injury in which the physical force of impact is directly imparted to the spinal cord,disrupting blood vessels,axons,and neural cell *** the primary injury,a cascade of secondary events begins,expanding the zone of neural tissue damage,and exacerbating neurological *** injury is a progressive condition characterized by pro-inflammatory cytokines,reactive oxygen species,oxidative damage,excitatory amino acids such as glutamate,loss of ionic homeostasis,mitochondrial dysfunction,and cell *** secondary phase lasts for several weeks or months and can be further subdivided into acute,subacute,and *** of the most frequent and devastating complications developed among the spinal cord injury population is cognitive *** risk of cognitive decline after spinal cord injury has been reported to be 13 times higher than in healthy *** exact etiology of this neurological complication remains unclear,however,many factors have been proposed as potential contributors to the development of this disorder,such as concomitant traumatic brain injury,hypoxia,anoxia,autonomic dysfunction,sleep disorders such as obstructive sleep apnea,body temperature dysregulation,alcohol abuse,and certain *** review focuses on a deep understanding of the pathophysiology of spinal cord injury and its relationship to cognitive *** highlight the main mechanisms that lead to the development of this neurological complication in patients with spinal cord injury.

关键词： autonomic dysfunction cognitive impairment spinal cord injury traumatic brain injury

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Output feedback adaptive super twisting sliding mode control for quadrotor UAvs

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Control Theory and Technology 2024年第1期22卷 92-105页

作者： oscar Salas-Peña Jesus DeLeón-Morales Susana v.Gutiérrez-Martínez École Centrale de Nantes-LS2N UMR 6004 CNRS44300NantesFrance Facultad de Ingeniería Mecánica y Eléctrica Universidad Autónoma de Nuevo León66451San Nicolás de Los GarzaMexico

In this paper, a sliding mode control with adaptive gain combined with a high-order sliding mode observer to solve the tracking problem for a quadrotor UAv is addressed, in presence of bounded external disturbances and parametric uncertainties. The high order sliding mode observer is designed for estimating the linear and angular speed in order to implement the proposed scheme. Furthermore, a Lyapunov function is introduced to design the controller with the adaptation law, whereas an analysis of finite time convergence towards to zero is provided, where sufficient conditions are obtained. Regarding previous works from literature, one important advantage of proposed strategy is that the gains of control are parameterized in terms of only one adaptive parameter, which reduces the control effort by avoiding gain overestimation. Numerical simulations for tracking control of the quadrotor are given to show the performance of proposed adaptive control–observer scheme.

关键词： Adaptive super twisting controller High-order sliding modes observer UAv

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Outcomes and variables that impact pneumatic retinopexies

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International Journal of Ophthalmology(English edition) 2024年第3期17卷 564-569页

作者： Maria v.Castanos Daniel vail oscar Otero-Marquez Yash Shah Avnish Deobhakta New York Eye and Ear Infirmary of Mount Sinai New York 10003New YorkUSA

●AIM:To evaluate the efficacy of pneumatic retinopexy(PR)in patients undergoing PR as primary treatment for rhegmatogenous retinal detachment(RRD)and analyze the factors associated with success and failure in the studied population.●METHODS:A retrospective chart review was done of patients with RRD treated with PR as primary management method treated at New York Eye and Ear Infirmary of Mount Sinai between January 2017 and December *** outcome measured success or failure of *** outcome measured best corrected visual acuity(BCvA)after PR.A separate risk analysis was done to identify and stratify risks associated with success and failure of PR.●RESULTS:A total of 179 eyes from 179 patients were included for final *** 83 patients(46.37%)achieved anatomical reattachment of the retina after primary PR with no need for additional *** 96 patients(53.63%)had a failed primary PR and required a PPv and 6 of them required pars plana vitrectomy(PPv)with scleral buckle(SB).In total,19 cases(10.61%)were done as temporizing pneumatics,18(94.74%)underwent PPv,and 1(5.26%)did not require further *** visual acuities at postoperative month 1(POM1)for patients who underwent primary PR successfully and for those that underwent PPv after,were 0.58(20/80)and 1.03(20/200)*** who met Pneumatic Retinopexy versus vitrectomy for the Management of Primary Rhegmatogenous Retinal Detachment Outcomes Randomized Trial(PIvOT)criteria had a statistically significant decreased risk of primary PR failing(hazard ratio 0.29,P=0.00).Majority of missed or new breaks were found superotemporally.●CONCLUSION:PR is a good treatment option for treating RRDs in patients that meet PIvOT criteria and can be conducted as a temporizing *** criteria and fovea on status decrease the risk of PR failure.

关键词： retina pneumatic retinopexy rhegmatogenous retinal detachment

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Characterization of Aquifers in Crystalline and Crystallophyll Basement Zones Using the Electrical Resistivity Method (Trails and Electrical Soundings) in the Gagnoa Region, (Central-Western Côte d’Ivoire)

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International Journal of Geosciences 2024年第6期15卷 511-523页

作者： oscar Zahibo Onétié Assoué Kouakou Sylvestre Kouadio Kotchi Rodrigue Orou Maxime Assa Abe Department of Geosciences Peleforo Gon Coulibaly University Korhogo Cte dIvoire Department of Agriculture and New Technologies University of San Pedro San Pedro Cte dIvoire

Introduction: Located in the central-western part of Côte d’Ivoire, the subsoil of the Gagnoa region is made up of sedimentary volcano formations and granitoids with developed fracturing. This complex Precambrian basement contains most of the region’s water resources. This is at the origin of the high failure rate during the various hydrogeological prospecting campaigns. Methodology: The database consists of resistivities from 42 holes and 51 trails drilled as part of the implementation of high-throughput drilling in the study area. The objective of this study is to deepen the knowledge of the fissured basement by interpreting profile curves and electrical soundings. It will be a question of classifying the different types of anomalies obtained on the profiles and their shapes. The orientation of the lineaments observed on the profiles was determined. Results: The interpretation of the geophysical data revealed various anomalies, the main ones being of the CC (Conductor Compartment) and CEDP (Contact between two bearings) types. These types of anomalies are mainly expressed in various forms: the “v”, “W” and “U” shapes. From these anomalies and the appearance of the electrical profiles, lineaments and their orientations were identified with N90-100, N130-140, N170-180 as major orientations. Conclusion: These results could contribute to a better understanding of the fractured environment of the Gagnoa region.

关键词： Basement Electrical Profiles Sounding Curves Resistivities

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Polygeneration Study of Low-to-Medium Enthalpy Geothermal Reservoirs in Mexico

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Journal of Thermal Science 2021年第3期30卷 1077-1087页

作者： CHÁvEZ oscar GODÍNEZ Francisco Tecnológico Nacional de México/I.T.Chihuahua.Av.Tecnológico 2909 C.P.31310ChihuahuaChihuahuaMéxico Instituto de Ingeniería Universidad Nacional Autónoma de MéxicoUNAMC.U.Ciudad de MéxicoC.P.04510México Polo Universitario de Tecnología Avanzada Universidad Nacional Autónoma de MéxicoVía de la Innovación No.410Autopista Monterrey-Aeropuertokm.10 PIITC.P.66629Apodaca Nuevo LeónMéxico

This study combines the thermodynamic analysis of a polygeneration system along with the numerical modelling of the thermal behavior of geothermal reservoirs in Mexico to exploit their *** reservoir was modeled as a porous medium assuming a five-spot well configuration and local thermal *** heat conduction-convection along with the Laplace equations were solved to compute temperature distributions,the useful life and the optimum distance between injection-extraction *** predicted temperature and pressure of the geothermal fluid at the outlet of the reservoir were exploited in the polygeneration system consisting of:(1)a Rankine cycle,(2)an absorption refrigeration cycle,and(3)a heat *** developed approach allows calculating both the optimal distance between injection-extraction wells and the global(utilization)efficiency of six arrangements(each composed by a reservoir connected to a polygeneration system)by assuming that reservoirs have a lifespan of 30 *** also show that:(a)due to the low efficiency of the Rankine cycle,very little thermal energy is converted into electrical one;(b)not only the temperature and the size are important when evaluating the power production performance of reservoirs,but also the permeability plays a fundamental role;(c)the first law efficiency of the polygeneration system ranges from 41.9%to 43.7%;(d)the utilization efficiency of the six arrangements lies in the range between 25.8%and 31%.

关键词： polygeneration system geothermal reservoir local thermal equilibrium low-to-medium enthalpy

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Analysis of the Supply Chain in Industrial Companies in Guayaquil,Ecuador-A Secondary Publication

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Proceedings of Business and Economic Studies 2024年第1期7卷 242-255页

作者： Génesis Belén Linzán Soledispa Betty Janeth Soledispa Canarte víctor Alfonso ChávezSoledispa oscar Rolando Fiallos González Universidad Politécnica Salesiana GuayaquilEcuador Universidad Estatal del Sur de Manabí ManabíEcuador Universidad Católica de Santiago de Guayaquil GuayaquilEcuador

This research clearly outlines the supply chain in a process of evolution and digital transformation,where the collaboration of its members is concentrated,having technological tools to help chain *** analyze the advantages that this transformation produces in the supply chain,as well as its different processes,this study has a systemic perspective that involves precise elements for organizational development,such as the different phases of each process,operations,logistics,and *** must be borne in mind that any strategy in industrial companies grants the automation of procedures in the supply chain and determines a product in any phase of production,making the organization more sensitive to any variation in *** methodology included a bibliographic and non-experimental review that allows a descriptive and analytical study,which details the various characteristics of the fact that is being investigated,collecting information through interviews with different people who are involved with industrial *** the results obtained,it was identified that digital transformation helps reduce costs and generates greater *** conclusion,it was obtained that the digital supply chain helps in each of the phases of the processes,these are supervised by devices that help to have fast and effective information.

关键词： Digital transformation Supply chain Industries 4.0 Sustainability

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Catenoidal Layers for the Allen-Cahn Equation in Bounded Domains

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Chinese Annals of Mathematics,Series B 2017年第1期38卷 13-44页

作者： oscar AGUDELO Manuel DEL PINO Juncheng WEI Department of Mathematics Zapadocescka Univerzita v PlzniPlzenCzech Republic Departamento de Ingenieria Matematica and CMM Universidad de ChileCasilla 170 Correo 3SantiagoChile Department of Mathematics University of British ColumbiaVancouver BC V6T 1Z2Canada

This paper presents a new family of solutions to the singularly perturbed Allen-Cahn equation α~2Δu + u(1- u^2) = 0 in a smooth bounded domain Ω R^3, with Neumann boundary condition and α > 0 a small parameter. These solutions have the property that as α→ 0, their level sets collapse onto a bounded portion of a complete embedded minimal surface with finite total curvature intersecting ?Ω orthogonally and that is non-degenerate respect to ?Ω. The authors provide explicit examples of surfaces to which the result applies.

关键词： Allen-Cahn equation Critical minimal surfaces Critical catenoid Infinite dimensional gluing method Neumann boundary condition

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Can plasticity make spatial structure irrelevant in individual-tree models?

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Forestry Studies in China 2014年第3期16卷 134-146页

作者： oscar Garcia University of Northern British Columbia 3333 University WayV2N 4Z9 Prince GeorgeBCCanada

Background： Distance-dependent individual-tree models have commonly been found to add little predictive power to that of distance-independent ones. One possible reason is plasticity, the ability of trees to lean and to alter crown and root development to better occupy available growing space. Being able to redeploy foliage （and roots） into canopy gaps and less contested areas can diminish the importance of stem ground locations. Methods： Plasticity was simulated for 3 intensively measured forest stands, to see to what extent and under what conditions the allocation of resources （e.g., light） to the individual trees depended on their ground coordinates. The data came from 50 x 60 m stem-mapped plots in natural monospecific stands of jack pine, trembling aspen and black spruce from central Canada. Explicit perfect-plasticity equations were derived for tessellation-type models. Results： Qualitatively similar simulation results were obtained under a variety of modelling assumptions. The effects of plasticity varied somewhat with stand uniformity and with assumed plasticity limits and other factors. Stand-level implications for canopy depth, distribution modelling and total productivity were examined. Conclusions： Generally, under what seem like conservative maximum plasticity constraints, spatial structure accounted for less than 10% of the variance in resource allocation. The perfect-plasticity equations approximated well the simulation results from tessellation models, but not those from models with less extreme competition asymmetry Whole-stand perfect plasticity approximations seem an attractive alternative to individual-tree models.

关键词： Growth and yield Competition Perfect plasticity approximation (PPA) siplab

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Effect of rhenium on the microstructure and mechanical behavior of Fe–2.25Cr–1.6W–0.25v-0.1C bainitic steels

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Journal of Materials Science & Technology 2017年第12期33卷 1487-1493页

作者： José Antonio Jiménez Manuel Carsí oscar Antonio Ruano Department of Physical Metallurgy Centro Nacional de lnvestigaciones MetalurgicasC.S.I.CAvda.Gregorio del Amo 828040 MadridSpain

A new ferritic creep resistant steel has been developed by eliminating Nb and adding 1.5 mass % Re to a ferritic steel grade T/P23 with the aim of enhancing its mechanical properties at high *** ingots of both steels, new grade and ASTM T/P 23, were hot rolled at 900℃ and then submitted to a thermal treatment consisting of solubilization at 1050℃ and tempering at 700℃. Tempered bainitic microstructures obtained contain second phases reinforcing carbide particles, mainly M_6C and M_（23）C_6 at the boundaries of both, prior austenite grains and bainitic ferrite laths, as well as MC within the grains. Mechanical properties at temperatures ranging from 540 to 600℃ were studied by strain-ratechange tests in compression at strain rates between 10^（-7） and 10^（-4）s^（-1）. These tests showed high stress exponents（n ≥ 20） and activation energies（Q ≈ 400 k J/mol） for both alloys, which were associated with a dislocation movement mechanism with a strong interaction between dislocations and precipitates. On the other hand, a creep exponent of 5 was derived for the stress dependence of minimum creep rate from conventional-type creep tests at 600℃. Although this stress exponent is usually related to a dislocation climb controlled creep mechanism, remarkable microstructural degradation observed with increasing creep time makes difficult to elucidate the true deformation mechanism controlling creep.

关键词： Creep resistant steel T/P23 Thermal treatment Tempered bainite High temperature mechanical properties Creep

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Morphological and productivity responses of Buffel grass(Cenchrus ciliaris)and Guinea grass(Panicum maximum)ecotypes to simulated grazing in a semi-arid environment

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Grassland Research 2022年第4期1卷 290-300页

作者： Bosco Kidake Kisambo Oliver v.Wasonga oscar K.Koech George N.Karuku Department of Land Resources Management and Agricultural Technology University of NairobiNairobiKenya Arid and Range Lands Research Institute—Kiboko Kenya Agricultural and Livestock Research Organization(KALRO)NairobiKenya

Background Livestock production is an economically significant activity in grassland-based production systems with herbivory,a critical process in modifying plant structure and regulating biomass dynamics in these *** A grazing simulation experiment was undertaken in a semi-arid environment in Kenya to determine the effects of clipping frequency and intensity on the morphology and productivity of Cenchrus ciliaris and Panicum maximum grass *** ecotypes were clipped at different frequencies(every 2,4,and 12 weeks)and different intensities(5,10,and 15 cm clipping heights).The morphological responses of the grass ecotypes and biomass yields were *** The grass ecotypes showed significantly(pvaried responses to cutting frequency and *** parameters,tillering,and biomass production were all affected by clipping frequency and *** highest dry matter(DM)yields were recorded under low frequency(LF)clipping,followed by moderate frequency(MF)clipping and high frequency(HF)*** clipping in *** ecotype Kilifi was 20%and 31%more compared to MF and HF *** significant difference in yields was found by cutting the *** ecotype Magadi at 4-and 12-week intervals,even though clipping at 2-week intervals cumulatively yielded less *** was a biomass yield reduction in *** ecotype Taveta of 23%and 25%for MF and HF clipping,respectively,while for ecotype Isinya,the reduction was 13%and 15%for MF and HF,*** intensity had a significant(pve yields in *** ecotypes,but not *** differences were apparent in both *** and *** ecotype DM *** The results in this study suggest that clipping range grass ecotypes less frequently(4-and 12-week intervals)and at 10 and 15 cm stubble heights results in higher biomass ***,LF and MF grazing and cutting strategies are advantageous for semi-arid lan

关键词： dry matter dryland grasslands grazing grazing frequency grazing intensity pastures rehabilitation

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