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The potential of starch-chitosan blends with poloxamer for the preparation of microparticles by spray-drying

Particuology 2024年第6期89卷 1-10页

作者： Juan Enrique Barranco-García Carolina Caicedo Enrique Javier Jiménez-Regalado Carlos Espinoza-González Graciela Morales Rocio Yaneli Aguirre-Loredo Abril Fonseca-García tecnológico Nacional de México/instituto tecnológico de Oaxaca Departamento de Química y BioquímicaAvenida Ing.Víctor Bravo Ahuja No.125Esquina Calzada Tecnológico68030OaxacaMexico Faculty of Engineering Unidad Central del Valle del Cauca(UCEVA)Carrera 17a 48-144763022TuluáColombia Centro de Investigación en Química Aplicada(CIQA) Blvd.Enrique Reyna Hermosillo 14025294SaltilloCoahuilaMexico Investigadoras por México CONAHCYT-CIQA Av.Insurgentes Sur 1562Col.Crédito Constructor03940Alcaldía Benito JuárezCDMXMexico

Using biopolymers as wall materials in spray drying poses challenges,particularly in attaining flowability and thermal stability among their physicochemical *** paper addresses these challenges by preparing microparticles using a blend of starch–chitosan and a poloxamer,commercially named Pluronic®*** aimed to elucidate the effects of varying poloxamer concentrations on the resulting particles through the spray drying *** with a poloxamer concentration of 3%(w/v)demonstrated a notably higher yield,especially when compared to those with 0%and 1%*** with 3%and 5%(w/v)poloxamer displayed a narrower particle size distribution,with the 3%blend showing a superior yield attributed to arrangements of blend components that improve flowability.X-ray diffraction analysis showcased the characteristic peaks of A-type starch form,with shifts suggesting enhanced interactions between *** with increased poloxamer content showed elevated thermal degradation temperatures,with the 3%blend registering a significant rise,opening avenues for encapsulating heat-sensitive *** study primarily focuses on the preparation and basic characterization of *** underscores the potential of blends with optimal poloxamer concentrations in microencapsulation,emphasizing further research to harness their capabilities thoroughly.

关键词： Biopolymer Starch Chitosan Pluronic®F127 Microparticles Spray drying

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Chitosan Nanoparticles as Biostimulant in Lettuce (Lactuca sativa L.) Plants

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Phyton-International Journal of Experimental Botany 2024年第4期93卷 777-787页

作者： Silvia C.Ramírez-Rodríguez Pablo Preciado-Rangel Marcelino Cabrera-De La Fuente Susana González-Morales Hortensia Ortega-Ortiz tecnológico Nacional de México Instituto Tecnológico de TorreónEjido AnaTorreónCoahuila27170México Departamento de Horticultura Universidad Autónoma Agraria Antonio NarroSaltillo25315México Departamento de Materiales Avanzados Centro de Investigación en Química AplicadaSaltilloCoahuila25294México

Biodegradable nanoparticles such as chitosan nanoparticles (CSNPs) are used in sustainable agriculture since theyavoid damage to the environment;CSNPs have positive effects such as the accumulation of bioactive compoundsand increased productivity in plants. This study aimed to investigate the impact of applying CSNPs on lettuce,specifically focusing on enzymatic activity, bioactive compounds, and yield. The trial was conducted using a completelyrandomized design, incorporating CSNPs: 0, 0.05, 0.1, 0.2, 0.4, and 0.8 mg mL−1. The doses of 0.4 mg mL−1improve yields up to 24.6% increases and 0.1 mg mL−1 of CSNPs increases total phenols by 31.2% and antioxidantcapacity by 34.6%. In addition, when low concentrations of CSNPs (0.05 and 0.1 mg L−1) were applied, anincrease in catalase was determined. The CSNPs represent a good alternative to be used as a biostimulant in sustainableagriculture because they improve the yield and quality of lettuce by increasing the bioactive compounds.

关键词： Biostimulant bioactive compounds enzymatic activity

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Plant growth and metabolism of exotic and native Crotalaria species for mine land rehabilitation in the Amazon

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Journal of Forestry Research 2024年第1期35卷 143-154页

作者： Hemelyn Soares das Chagas Rafael Silva Guedes Markus Gastauer Paula Godinho Ribeiro Allan Klynger da Silva Lobato Cecílio Frois Caldeira Fabrício William deÁvila AndréRodrigues dos Reis Silvio Junio Ramos instituto tecnológico vale Rua Boaventura da Silva955BelémPA 66055-090Brazil Universidade Federal do Sul e Sudeste do Pará XinguaraPABrazil Núcleo de Pesquisa Vegetal Básica e Aplicada Universidade Federal Rural da AmazôniaParagominasPABrazil Departamento de Engenharia Florestal Universidade Estadual do Centro-Oeste/UNICENTROIratiPRBrazil School of Sciences and Engineering São Paulo State University(UNESP)TupãSP.CEP 17602-496Brazil

Despite its enormous benefits,mining is respon-sible for intense changes to vegetation and soil ***,after extraction,it is necessary to rehabilitate the mined areas,creating better conditions for the establishment of plant species which is *** study evaluated mineral and organic fertilization on the growth,and carbon and nitrogen(N)metabolism of two Crotalaria species[Cro-talaria spectabilis(exotic species)and Crotalaria maypu-rensis(native species from Carajás Mineral Province(CMP)]established on a waste pile from an iron mine in CMP.A control(without fertilizer application)and six fertilization mixtures were tested(i=NPK;ii=NPK+micronutrients;iii=NPK+micronutrients+organic compost;iv=PK;v=PK+micronutrients;vi=PK+micronutrients+organic compost).Fertilization contributed to increased growth of both species,and treatments with NPK and micronutrients had the best results(up to 257%***),while organic fertilization did not show *** Crotalaria had a greater number of nodules,higher nodule dry mass,chlorophyll a and b contents and showed free ammonium as the predominant N form,reflecting greater increments in biomass compared to native *** having lower growth,the use of this native species in the rehabilitation of mining areas should be considered,mainly because it has good development and meets current government legislation as an opportunity to restore local biodiversity.

关键词： Biological nitrogen fixation Mining Nitrogen metabolism Plant nutrition

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Tailings Dam Mining, Theoretical Considerations, and Circular Economy: A Review

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Journal of Geoscience and Environment Protection 2024年第9期12卷 77-92页

作者： Eduardo da Rosa Aquino Vidal Félix Navarro Torres Irvyn Laurence Paniz instituto tecnolgico vale - Minerao Ouro Preto Brazil

Mining in tailings dams has emerged as a strategic alternative for mining companies for both economic and environmental reasons. Owing to technological limitations in recent decades, many of these dams have high metal contents, emphasizing the need to evaluate the quality of these residues, especially considering the technological advancements in current concentration plants. An economic viability analysis associated with reusing these materials is crucial. From an environmental point of view, improving mining techniques for dams by considering both safety and feasibility is an advantageous option in decommissioning processes and alignment in the circular economy. In this context, representing these tailings in terms of grade quality and granulometry, as well as the associated contaminants, is essential. Geostatistical estimation and simulation methods are valuable tools for modeling tailings bodies, but they require a reliable sampling campaign to ensure acceptably low errors. From an operational perspective, tailings recovery can be conducted via dry methods, such as mechanical excavation, or hydraulic methods, such as dredging or hydraulic blasting. Dredging is a commonly used method, and cutter suction dredgers, which require pumping to transport fragmented material, are the most commonly used tools. In this paper, some practical applications of geostatistical methods for resource quantification in tailings dams will be discussed. Additionally, the main mining methods for tailings recovery in dams will be presented. Emphasis will be given to the dredging method, along with the key analysis parameters for sizing dredgers, pumps, and pipelines.

关键词： Mining in Tailings Dams Geostatistical Methods Grade Quality Dredging

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Coffee Leaf Rust(Hemileia vastatrix)Disease in Coffee Plants and Perspectives by the Disease Control

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Phyton-International Journal of Experimental Botany 2024年第5期93卷 923-949页

作者： Alexis Salazar-Navarro Victor Ruiz-Valdiviezo Jose Joya-Dávila Daniel Gonzalez-Mendoza instituto de Ciencias Agrícolas de la Universidad Autónoma de Baja California(ICA-UABC) Nuevo LeónBaja California21705México Laboratorio de Biología Molecular del instituto tecnológico Nacional de Tuxtla Gutierrez(TecNM) Tuxtla GutierrezChiapas29050México Facultad de Ciencias Agronómicas Campus V.Universidad Autónoma de Chiapas(UNACH) VillafloresChiapas30470México

Coffee Leaf Rust(CLR)is caused by Hemileia vastatrix in Coffea *** is one of the most dangerous phytopathogens for coffee plantations in terms of coffee productivity and coffee cup *** this review,we resume the problem of CLR in Mexico and the pathogenesis of *** review abord plant-pathogen interactions which lead a compatible or incompatible interactions and result in CLR disease or resistance,*** review abord Coffea *** response pathways involved in *** ***,current measures to control *** proliferation and germination were aborded focused on phytosanitary actions,and biological and chemical ***,new trendlines to reduce the impact of CLR as nanoparticles and nanotechnology were analyzed.

关键词： Coffee leaf rust Coffea arabica pathogenesis nanoparticles biological control

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Metal-modulated epitaxy of Mg-doped Al_(0.80)In_(0.20)N-based layer for application as the electron blocking layer in deep ultraviolet light-emitting diodes

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Journal of Semiconductors 2024年第5期45卷 80-89页

作者： Horacio Irán Solís-Cisneros Carlos Alberto Hernández-Gutiérrez Enrique Campos-González Máximo López-López Optomechatronics Group Tecnológico Nacional de México Campus Tuxtla Gutiérrezcarretera Panamericana 1080C.P.29050Tuxtla GutiérrezChiapasMéxico Departamento de Física Instituto Nacional de Investigaciones NuclearesCarretera México-Toluca s/nC.P.52750La Marquesa OcoyoacacMéxico Departamento de Física Centro de Investigación y estudios Avanzados del Instituto Politécnico NacionalAv.Instituto Politécnico Nacional 2508San Pedro ZacatencoGustavo A.Madero07360 Ciudad de MéxicoCDMXMéxico

This work reports the growth and characterization of p-AlInN layers doped with Mg by plasma-assisted molecular beam epitaxy(PAMBE).AlInN was grown with an Al molar fraction of 0.80 by metal-modulated epitaxy(MME)with a thickness of 180 nm on Si(111)substrates using AlN as buffer *** substrate temperatures were used to enhance the incorporation of indium atoms into the alloy without clustering,as confirmed by X-ray diffraction(XRD).Cathodoluminescence measurements revealed ultraviolet(UV)range ***,Hall effect measurements indicated a maximum hole mobility of 146 cm^(2)/(V∙s),corresponding to a free hole concentration of 1.23×10^(19)cm^(−3).The samples were analyzed by X-ray photoelectron spectroscopy(XPS)estimating the alloy composition and extracting the Fermi level by valence band ***-doped AlInN layers were studied for use as the electron-blocking layer(EBL)in LED *** varied the Al composition in the EBL from 0.84 to 0.96 molar fraction to assess its theoretical effects on electroluminescence,carrier concentration,and electric field,using SILVACO *** results from this study highlight the importance and capability of producing high-quality Mg-doped p-AlInN layers through *** simulations suggest that an Al content of 0.86 is optimal for achieving desired outcomes in electroluminescence,carrier concentration,and electric field.

关键词： metal-modulated epitaxy AlInN DUV-LED EBL simulation

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HVSR analysis of pumice sands for sediment depth characterization:A case study for Guadalajara,Mexico

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Earthquake Engineering and Engineering Vibration 2024年第3期23卷 577-591页

作者： Hafid Salgado M. Alejandro Ramírez-Gaytan Adolfo Preciado Christian R.Escudero Departamento de Ciencias Exactas Centro Universitario de la CostaUniversidad de GuadalajaraCP.48280 Puerto VallartaJaliscoMéxico Departamento de Ciencias Computacionales Centro Universitario de Ciencias Exactas e IngenieríaUniversidad de GuadalajaraCP.44430 GuadalajaraJaliscoMéxico Departamento del Hábitat y Desarrollo Urbano Instituto Tecnológico y de Estudios Superiores de Occidente(ITESO)CP.45604 TlaquepaqueMéxico

The horizontal to vertical spectral ratio(HVSR)methodology is used here to characterize pumice soils and to image the three-dimensional surface geometry of Guadalajara,*** to other Latin American cities,Guadalajara is exposed to high seismic risk,with the particularity of being the largest urban settlement in Latin America built on pumice *** has not yet been tested to characterize subsoil depths in pumice *** to the questionable use of traditional geotechnical tests for the analysis of pumice soils,HVSR provides an alternative for its characterization without altering its fragile and porous *** this work,resonance frequency(F0)and peak amplitude(A0)are used to constrain the depth of the major impedance contrast that represents the interface between bedrock and pumice *** were compared with borehole depths and other available geotechnical and geophysical data and show good *** of the profiles estimated on the riverbanks that cross the city,reveals different subsoil thickness that could have an impact on different site responses on riverine areas to an eventual *** and academic efforts are combined in this work to characterize depth sediments,an important parameter that impacts the regulations for construction in the city.

关键词： subsoil of Guadalajara shallow soil thickness bedrock depth pumice soil characterization

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Analysis of a passive ankle exoskeleton for reduction of metabolic costs during walking

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Defence Technology（防务技术） 2024年第7期37卷 62-68页

作者： Luís Quinto Pedro Pinheiro Sergio B.Goncalves Ivo Roupa Paula Simoes Miguel Tavares da Silva CINAMIL Academia MilitarInstituto Universitario MilitarLisbonPortugal IDMEC Instituto Superior TecnicoUniversidade de LisboaLisbonPortugal

Modern conflicts demand substantial physical and psychological exertion,often resulting in fatigue and diminished combat or operational *** exoskeletons have been developed recently to address these challenges,presenting various limitations that affect their operational or everyday *** article evaluates the performance of a dual-purpose passive ankle exoskeleton developed for the reduction of metabolic costs during walking,seeking to identify a force element that could be applied to the target *** on the 6-min walk test,twenty-nine subjects participated in the study using three different force *** results indicate that it is possible to reduce metabolic expenditure while using the developed ***,the comfort and range of motion results verify the exoskeleton's suitability for use in uneven terrain and during extended ***,the choice of the force element should be tailored to each user,and the control system should be adjustable to optimise the exoskeleton's performance.

关键词： Ankle passive exoskeleton Metabolic cost reduction Dual-use exoskeleton Gait Biomechanics

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Transcriptomic responses to drought stress in the Patagonian southern beech Nothofagus alpina

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Ecological Processes 2024年第2期13卷 192-203页

作者： Rita Maria Lopez Laphitz María Verónica Arana Santiago Agustín Varela Leandro Aníbal Becker Carolina Soliani María Marta Azpilicueta Paula Marchelli Nicolás Bellora instituto de Diversidad y Evolución Austral (CENPAT CONICET ) instituto de Investigaciones Forestales y Agropecuarias Bariloche (IFAB INTA CONICET ) instituto de tecnologías Nucleares para la Salud (CONICET )

Background Deciphering the genetic architecture of drought tolerance could allow the candidate genes identification responding to water stress. In the Andean Patagonian forest, the genus Nothofagus represents an ecologically relevant species to be included in different genomic studies. These studies are scarce in South American ecosystems however represent an important source of genomic data in order to interpret future climate-change environment scenarios of these emblematic forests. Here, we achieved the assemblage of the transcriptome of N. alpina while searching for key genes of activated or suppressed metabolic pathways in response to drought *** De novo transcriptome assembly resulted in 104,030 transcripts. Following confirmation of drought conditions, based on reduction of leaf water potential and stomatal conductance, a differential gene expression analysis resulted in 2720 significantly expressed genes(1601 up-regulated and 1119 down-regulated). Enrichment analysis(over-representation analysis and gene set enrichment analysis) resulted in more than one hundred stress-responsive term ontologies(i.e. biological processes) and pathways. Terms such as response to abscisic acid and pathways such as plant hormone signal transduction or starch and sucrose metabolism were over-represented. Protein–protein interaction assessment resulted in networks with significantly expressed top common hub gene clusters(e.g. planttype cell wall biogenesis among down-regulated or ABA-signalling among up-regulated). These networks evidenced important regulators at gene expression such as transcriptional *** Responses of N. alpina seedlings to drought stress were evidenced by the activation of several genes linked to GO biological processes and KEGG pathways, which were mainly based on over-expression of specific protein kinases, phosphatases, synthases and transcription factors. This suggests an up-regulation of signalling pathways, triggered through pla

关键词： Climate change Differential gene expression Hub genes Patagonia Temperate forest

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Optimization of room-and-pillar dimensions using automated numerical models

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International Journal of Mining Science and Technology 2019年第5期29卷 797-801页

作者： Gian Franco Napa-García Tais Renata Camara Vidal Félix Navarro Torres Mining Instituto Tecnológico ValeSanta LuziaMG 33040-900Brazil Exploration and Mineral Projects VALE S.A.Santa LuziaMG 33040-900Brazil

This paper presents an optimization methodology for the geometric configuration of a room–and–pillar mining project,considering safety and operational restrictions while maximizing ore *** underground manganese mine was chosen as a case study to investigate the capabilities of the presented methodology.A software package(OPTIMINE)was implemented to address the computational demand in an automated ***–dimensional finite difference analyses were performed in FLAC3D and used as implicit functions to consider safety in terms of the factor of safety and room *** obtained results showed that recovery could be increased from 44%to more than 80%in a safe manner.

关键词： Optimization Safety Room and pillar mining Ore recovery 3D numerical modeling

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