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

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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

Generalized height-Diameter Models for Pinus montezumae Lamb. and Pinus pseudostrobus Lindl. Plantations in Michoacan, Mexico

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Open Journal of Forestry 2024年第3期14卷 214-232页

作者： Jonathan hernández-Ramos Valentín José Reyes-hernández héctor Manuel De los Santos-Posadas Aurelio Manuel Fierros-gonzález Enrique Buendía-Rodríguez Gerónimo Quiñonez-Barraza Instituto Nacional de Investigaciones Forestales Agrcolas y Pecuarias (INIFAP)-Campo Experimental Bajo Celaya Guanajuato Mxico Colegio de Postgraduados (COLPOS) Campus Montecillo Mxico INIFAP Campo Experimental Valle de Mxico Texcoco Mxico INIFAP Campo Experimental Valle del Guardiana Durango Mxico

Tree height (h) in a natural stand or forest plantation is a fundamental variable in management, and the use of mathematical expressions that estimate h as a function of diameter at breast height (d) or variables at the stand level is a valuable support tool in forest inventories. The objective was to fit and propose a generalized h-d model for Pinus montezumae and Pinus pseudostrobus established in forest plantations of Nuevo San Juan Parangaricutiro, Michoacan, Mexico. Using nonlinear least squares (NLS), 10 generalized h-d models were fitted to 883 and 1226 pairs of h-d data from Pinus montezumae and Pinus pseudostrobus, respectively. The best model was refitted with the maximum likelihood mixed effects model (MEM) approach by including the site as a classification variable and a known variance structure. The Wang and Tang equation was selected as the best model with NLS;the MEM with an additive effect on two of its parameters and an exponential variance function improved the fit statistics for Pinus montezumae and Pinus pseudostrobus, respectively. The model validation showed equality of means among the estimates for both species and an independent subsample. The calibration of the MEM at the plot level was efficient and might increase the applicability of these results. The inclusion of dominant height in the MEM approach helped to reduce bias in the estimates and also to better explain the variability among plots.

关键词： Random Covariate Random Effects Variance Structure Forest Inventories Forest Management Mixed Models

Biomaterial engineering strategies for modeling the Bruch's membrane in age-related macular degeneration

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Neural Regeneration Research 2024年第12期19卷 2626-2636页

作者： Blanca Molins Andrea Rodríguez Víctor Llorenç Alfredo Adán Group of Ocular Inflammation:Clinical and Experimental Studies Institut d’Investigacions Biomèdiques AgustíPi I Sunyer(IDIBAPS)BarcelonaSpain Institut Clínic d’Oftalmologia(ICOF) Hospital Clínic BarcelonaSpain

Age-related macular degeneration,a multifactorial inflammatory degenerative retinal disease,ranks as the leading cause of blindness in the ***,there is a scarcity of curative therapies,especially for the atrophic advanced form of age-related macular degeneration,likely due to the lack of models able to fully recapitulate the native structure of the outer blood retinal barrier,the prime to rget tissue of age-related macular *** in vitro systems rely on 2D monocultures unable to adequately reproduce the structure and function of the outer blood retinal barrier,integrated by the dynamic interaction of the retinal pigment epithelium,the Bruch's membrane,and the underlying *** Bruch's membrane provides structu ral and mechanical support and regulates the molecular trafficking in the outer blood retinal barrier,and therefo re adequate Bruch's membrane-mimics are key for the development of physiologically relevant models of the outer blood retinal barrie *** the last years,advances in the field of biomaterial engineering have provided novel approaches to mimic the Bruch's membrane from a variety of *** review provides a discussion of the integrated properties and function of outer blood retinal barrier components in healt hy and age-related macular degeneration status to understand the requirements to adequately fabricate Bruch's membrane biomimetic ***,we discuss novel materials and techniques to fabricate Bruch's membrane-like scaffolds for age-related macular degeneration in vitro modeling,discussing their advantages and challenges with a special focus on the potential of Bruch's membrane-like mimics based on decellularized tissue.

关键词： age-related macular degeneration Bruch's membrane decellularization retinal pigment epithelium scaffold

Myelin histology:a key tool in nervous system research

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Neural Regeneration Research 2024年第2期19卷 277-281页

作者： Óscar Darío García-García Víctor Carriel Jesús Chato-Astrain Department of histology Tissue Engineering GroupUniversity of Granada&Instituto de Investigación Biosanitaria ibs.GRANADAGranadaSpain

The myelin sheath is a lipoprotein-rich,multilayered structure capable of increasing conduction velocity in central and peripheral myelinated nerve *** to the complex structure and composition of myelin,various histological techniques have been developed over the centuries to evaluate myelin under normal,pathological or experimental ***,methods to assess myelin integrity or content are key tools in both clinical diagnosis and neuroscience *** this review,we provide an updated summary of the composition and structure of the myelin sheath and discuss some histological procedures,from tissue fixation and processing techniques to the most used and practical myelin histological staining *** the lipoprotein nature of myelin,the main features and technical details of the different available methods that can be used to evaluate the lipid or protein components of myelin are described,as well as the precise ultrastructural techniques.

关键词： fluorescence microscopy histology light microscopy lipid histochemistry metallographic techniques myelin histochemistry myelin immunohistochemistry myelin structure&composition myelin ultrastructural evaluation tissue fixation&processing

Freeze-thaw cycles and associated geomorphology in a post-glacial environment:current glacial,paraglacial,periglacial and proglacial scenarios at Pico de Orizaba volcano,Mexico

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Journal of Mountain Science 2024年第6期21卷 1954-1977页

作者： Víctor SOTO Carlos M.WELSh R. Kenji YOShIKAWA hugo DELGADO GRANADOS Centro de Ciencias de la Tierra Universidad VeracruzanaCircuito Gonzalo Aguirre BeltránS/NZona Universitaria91090XalapaMéxico Water and Environmental Research Center University of Alaska FairbanksFairbanksAlaska 99775USA Instituto de Geofísica Universidad Nacional Autónoma de MéxicoCiudad de México 04150México Department of Earth and Environmental Sciences Ludwig Maximilians UniversitätMunich 80333Germany

The glacial history of Pico de Orizaba indicates that during the Last Glacial Maximum,its icecap covered up to~3000 m asl;due to the air temperature increasing,its main glacier has retreated to 5050 m *** retraction of the glacier has left behind an intense climatic instability that causes a high frequency of freeze-thaw cycles of great intensity;the resulting geomorphological processes are represented by the fragmentation of the bedrock that occupies the upper parts of the *** is a notable lack of studies regarding the fragmentation and erosion occurring in tropical high mountains,and the associated geomorphological risks;for this reason,as a first stage of future continuous research,this study analyzes the freezing and thawing cycles that occur above 4000 m asl,through continuous monitoring of surface ground *** results allow us to identify and characterize four zones:glacial,paraglacial,periglacial and *** was found that the paraglacial zone presents an intense drop of temperature,of up to~9℃ in only sixty *** rock fatigue and intense freeze-thaw cycles that occur in this area are responsible for the high rate of rock disintegration and represent the main factor of the constant slope dynamics that occur at the *** activity decreases,both in frequency and intensity,according to the distance to the glacier,which is where the temperature presents a certain degree of stability,until reaching the proglacial zone,where cycles are almost non-existent,and therefore there is no gelifraction *** geomorphological processes have resulted in significant alterations to the mountain slopes,which can have severe consequences in terms of risk and water.

关键词： Freeze-Thaw Gelifraction Mountain mechanical erosion Periglacial geomorphology Postglacial scenarios

Low serum levels of ghrelin are associated with gallstone disease

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World Journal of Gastroenterology 2006年第19期12卷 3096-3100页

作者： Nahum Méndez-Sánchez Guadalupe Ponciano-Rodríguez Luisa Bermejo-Martínez Antonio R Villa Norberto C Chávez-Tapia Daniel Zamora-Valdés Raúl Pichardo-Bahena Blanca Barredo-Prieto Martha h Uribe-Ramos Martha h Ramos héctor a baptista-gonzález Misael Uribe Liver Unit Biomedical Research Department Medica Sur Clinic and FoundationMexico CityMexico Faculty of Medicine National Autonomous University of Mexico (UNAM) Mexico CityMexico Clinical Research Department National Institute of Perinatology Mexico CityMexico Clinical Epidemiology Unit National Institute of Medical Sciences and Nutrition Mexico CityMexico

瞄准：在胆石疾病探索 ghrelin 的角色。方法：我们在 150 个题目，执行了代表性的研究 38 与胆石(盒子) 和 112 控制。我们也各在二十件胆囊样品做了即时 PCR-RT 研究。身体集体索引(BMI ) ，浆液胰岛素， ghrelin，和浆液类脂化合物... 详细信息

瞄准：在胆石疾病探索 ghrelin 的角色。方法：我们在 150 个题目，执行了代表性的研究 38 与胆石(盒子) 和 112 控制。我们也各在二十件胆囊样品做了即时 PCR-RT 研究。身体集体索引(BMI ) ，浆液胰岛素， ghrelin，和浆液类脂化合物被测量。逻辑回归分析(univariate 并且多变量) 被进行估计与浆液 ghrelin 集中联系的胆石疾病的概率。结果：盒子与在性分发的控制统计上不同(P = 0.01 ) ，年龄(53 对 44 年， P = 0.002 ) ， BMI (28 对 25；P = 0.004 ) ，并且葡萄糖(5.26 对 4.98 mmol/L；P = 0.05 ) 。没有新陈代谢的症候群，在第三 tercile 上面的 ghrelin 浆液层次的流行在题目是更低的(P hrelin 价值比中部的价值高时，我们发现了保护的效果(或 = 0.27， 95%CI 0.09-0.82， P = 0.02 ) 。二十(20%) 胆囊标本表示了 ghrelin mRNA。结论：浆液 ghrelin 集中与 GD 的保护的效果被联系。

关键词：血液水平胆结石肥胖胆囊

From liver to hormones:The endocrine consequences of cirrhosis

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World Journal of Gastroenterology 2024年第9期30卷 1073-1095页

作者： Juan Eduardo Quiroz-Aldave Elman Rolando Gamarra-Osorio María del Carmen Durand-Vásquez Luciana del Pilar Rafael-Robles Jhean Gabriel gonzáles-Yovera María Alejandra Quispe-Flores Luis Alberto Concepción-Urteaga Alejandro Román-gonzález José Paz-Ibarra Marcio José Concepción-Zavaleta Non-communicable Diseases Endocrinology Research LineHospital de Apoyo ChepénChepén 13871Peru Department of Endocrinology Hospital Víctor Lazarte EchegarayTrujillo 13006Peru Department of Endocrinology Clínica Javier PradoLima 15046Peru Department of Gastroenterology Hospital Nacional Guillermo Almenara IrigoyénLima 15018Peru Department of Endocrinology Hospital de Emergencias GrauLima 15001Peru Internal Medicine Hospital Regional Docente de TrujilloTrujillo 13011Peru Department of Endocrinology Hospital Universitario de San Vicente FundaciónMedellin 050010Colombia Internal Medicine Universidad de AntioquiaMedellín 050010Colombia School of Medicine Universidad Nacional Mayor de San MarcosLima 15081Peru Department of Endocrinology Hospital Nacional Edgardo Rebagliati MartinsLima 15072Peru Carrera de Medicina humana Universidad Científica del SurLima 15067Peru

hepatocrinology explores the intricate relationship between liver function and the endocrine *** liver diseases such as liver cirrhosis can cause endocrine disorders due to toxin accumulation and protein synthesis *** its importance,assessing endocrine issues in cirrhotic patients is frequently *** article provides a comprehensive review of the epidemiology,pathophysiology,diagnosis,and treatment of endocrine disturbances in liver *** review was conducted using the PubMed/Medline,EMBASE,and Scielo databases,encompassing 172 *** cirrhosis is associated with endocrine disturbances,including diabetes,hypoglycemia,sarcopenia,thyroid dysfunction,hypogonadotropic hypogonadism,bone disease,adrenal insufficiency,growth hormone dysfunction,and secondary *** optimal tools for diagnosing diabetes and detecting hypoglycemia are the oral glucose tolerance test and continuous glucose monitoring system,*** can be assessed through imaging and functional tests,while other endocrine disorders are evaluated using hormonal assays and imaging *** options include metformin,glucagon-like peptide-1 analogs,sodium-glucose co-transporter-2 inhibitors,and insulin,which are effective and safe for diabetes *** standards are followed for managing hypoglycemia,and hormone replacement therapy is often necessary for other endocrine *** transplantation can address some of these problems.

关键词： Diabetes mellitus hypoglycemia Thyroid diseases hypogonadism Metabolic bone diseases Liver cirrhosis

Geochemistry and mineralogy of beach sediments in the northern Gulf of Mexico,Tamaulipas state, Mexico: implication for provenance

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Journal of Palaeogeography 2024年第3期13卷 375-400页

作者： Mayank Shukla Sanjeet K.Verma Mayla A.Ramos-Vázquez John S.Armstrong-Altrin Karla R.hernández-Martínez Sumit Mishra Vivek P.Malviya héctor hernández-Mendoza Posgrado de la División de Geociencias Aplicadas Instituto Potosino de Investigación Científica y Tecnológica (IPICYT) División de Geociencias Aplicadas Instituto Potosino de Investigación Científica y Tecnológica (IPICYT) Universidad Nacional Autónoma de México Instituto de Ciencias del Mar y Limnología Unidad de Procesos Oceanicos y Costeros Ciudad Universitaria Department of Marine Sciences Bharathidasan University Instituto de Geociencias Universidad Nacional Autónoma de México Department of Applied Geology Dr.Harisingh Gour Central University Instituto de Investigación de Zonas Desérticas Universidad Autónoma de San Luis Potosí Universidad del Centro de México

Geochemical and mineralogical studies were performed in the La Pesca(LP) and Tesoro Altamira(TA) beach sediments, located in the Tamaulipas state, northern Gulf of Mexico. The main aim of this study is to infer the weathering history and provenance and to discriminate the tectonic environment of the beach sediments. The sediments are composed of quartz with small amounts of accessory minerals such as plagioclase, calcite, orthoclase, microcline, and zircon. Both beach sediments are classified as fine-grained and very well sorted, however LP has coarse skewed and leptokurtic sediments, whereas TA has fine-skewed and very leptokurtic sediments. The chemical index of weathering(CIW') indicates intense weathering in the source area. The quartz grain microtextures in the LP and TA are classified into mechanical, chemical, and mechanical/chemical origin. Mechanical features such as fractures, pits, percussion marks, abrasion fatigue, and V-shaped marks favor high-energy littoral, fluvial, subaqueous-marine, and aeolian environments. The chemical features indicate solution pits and crystalline overgrowth, which suggests a silica saturated marine environment. The mechanical/chemical features display adhering particles and elongated depressions suggest formation in a sub-aqueous nearshore marine environment. Major and trace elements-based provenance discrimination diagrams indicate a felsic source derived from the Mesa Central(MC), Sierra Madre Oriental(SMOr) and Oaxaquia terranes. The major and trace element concentrations imply a passive margin setting for the northern Gulf of Mexico, which is consistent with the general geology.

关键词： Beach sediments Geochemistry Mineralogy Provenance Tamaulipas Tectonic setting

The ecological scale mediates whether trees experience drought legacies in radial growth

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Forest Ecosystems 2023年第3期10卷 298-306页

作者： héctor hernández-Alonso Jaime Madrigal-gonzález Fernando Silla Area of Ecology Faculty of BiologyUniversidad de SalamancaE-37007SalamancaSpain iuFOR-EiFAB Campus de SoriaUniversidad de ValladolidE-42004SoriaSpain

The impact of lag effects produced by disturbances on primary production has been a major concern among ecologists during the last *** and extreme climatic events are imposing drastic reductions in radial growth of trees as evidenced in tree-rings series Dendrochronological samples are obtained at tree level but analyzed at an aggregated scale(i.e.,mean chronologies),although aggregating tree-ring chronology on a regional scale may reduce the possibility of studying the variability of individual tree response to drought,by amplifying the average population ***,we conducted experimental research in which 370 trees of 5 species were analyzed to assess the potential statistical and scaling issues that may occur when using regressionbased methods to analyze ecosystem responses to *** legacy effects were quantified using individual and aggregated ***,lag effects were validated using confidence and prediction intervals to identify values falling outside the certainty of the climate-growth model Individual scale legacy effects contrasted with confidence intervals were commonly distributed across species but were scarce when compared with prediction *** analysis of aggregated scale legacies detected significant growth reductions when validated using prediction intervals;however,individual scale legacy lag effects were not *** finding directly contrasts the results obtained when using an aggregated *** results provide empirical evidence on how aggregating ecological data to infer processes that emerge from an individual scale can lead to distorted *** therefore encourage the use of individual based statistical and ecological procedures to analyze tree rings as a means of further understanding the ecosystem responses to disturbances.

关键词： Legacy effects Drought disturbances Tree growth Tree-ring width Dendrochronology Individual scale Mountainous forests