检索结果-南通市图书馆

c-Abl kinase at the crossroads of healthy synaptic remodeling and synaptic dysfunction in neurodegenerative diseases

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2023年第2期18卷 237-243页

作者： Daniela A.Gutiérrez América Chandía-Cristi María JoséYáñez Silvana Zanlungo Alejandra R.Alvarez Cell Signaling Laboratory Department of Cellular and Molecular BiologyCenter for Aging and Regeneration(CARE)Millennium Institute on Immunology and ImmunotherapyBiological Sciences FacultyPontificia Universidad Católica de ChileSantiagoChile School of Medical Technology Health Sciences FacultyUniversidad San SebastianSede Los LeonesSantiagoChile department of Gastroenterology Faculty of MedicinePontificia Universidad Católica de ChileSantiagoChile

Our ability to learn and remember depends on the active formation,remodeling,and elimination of synapses.Thus,the development and growth of synapses as well as their weakening and elimination are essential for neuronal rewiring.The structural reorganization of synaptic complexes,changes in actin cytos keleton and organelle dynamics,as well as modulation of gene expression,determine synaptic plasticity.It has been proposed that dys regulation of these key synaptic homeostatic processes underlies the synaptic dysfunction observed in many neurodegenerative diseases.Much is known about downstream signaling of activated N-methyl-D-aspartate andα-amino-3-hydroxy-5-methyl-4-isoazolepro pionate receptors;howeve r,other signaling pathways can also contribute to synaptic plasticity and long-lasting changes in learning and memory.The non-receptor tyrosine kinase c-Abl(ABL1)is a key signal transducer of intra and extracellular signals,and it shuttles between the cyto plasm and the nucleus.This review focuses on c-Abl and its synaptic and neuronal functions.Here,we discuss the evidence showing that the activation of c-Abl can be detrimental to neurons,promoting the development of neurodegenerative diseases.Nevertheless,c-Abl activity seems to be in a pivotal balance between healthy synaptic plasticity,regulating dendritic spines remodeling and gene expression after cognitive training,and synaptic dysfunction and loss in neurodegenerative diseases.Thus,c-Abl genetic ablation not only improves learning and memory and modulates the brain genetic program of trained mice,but its absence provides dendritic spines resiliency against damage.Therefo re,the present review has been designed to elu cidate the common links between c-Abl regulation of structural changes that involve the actin cytos keleton and organelles dynamics,and the transc riptional program activated during synaptic plasticity.By summarizing the recent discove ries on c-Abl functions,we aim to provide an overview of how its inhibition co uld be a potentially fruitful

关键词： actin cytoskeleton activity-dependent plasticity Alzheimer's disease c-Abl dendritic spines learning synapse synaptic plasticity transcription tyrosine kinase

Response to lipopolysaccharide in Octodon degus pups produces age-related sickness behavior but does not have effects in juveniles

在线全文

学校读者我要写书评

暂无评论

Integrative Zoology 2019年第3期14卷 235-247页

作者： Natalia RAMIREZ-OTAROLA Janyra ESPINOZA Alexis M.KALERGIS Pablo SABAT department of Ecological Sciences Science FacultyUniversidad de ChileSantiagoChile Millennium Institute Immunology and Immunotherapy Departamento de Genética Molecular y MicrobiologíaFacultad de Ciencias BiológicasPontificia Universidad Católica de ChileSantiagoChile departamento de Endocrinología Facultad de MedicinaPontificia Universidad Católica de ChileSantiagoChile department of Ecology Center of Applied Ecology&SustainabilityBiological Sciences FacultyPontificia Universidad Católica de ChileSantiagoChile

During vertebrate development,the immune function is inefficient and is mainly controlled by innate defense.While there have been detailed studies of various aspects of innate immune function,the effects of this function in the growth of vertebrates is still not well known.Similarly,there is little information regarding how early endotoxin exposure would affect juvenile phenotypes,specifically in a non-model mammal like a precocial rodent.We evaluated the response to an antigen and its cost in offspring of the rodent Octodon degus.We inoculated pups at 4 different ages(8,15,22 and 30 days after birth)with an antigen to determine the ontogeny and costs of the response to an endotoxin.We assessed changes in body mass,body temperature,sickness behavior and the levels of a key mediator of the inflammatory response,the cytokine interleukin-1β.We also determined the effects of early endotoxin exposure on the resting metabolic rate of juvenile animals(i.e.90 days after birth).The cytokine levels,body mass and body temperature were unaffected by time of inoculation and treatment.However,pups subjected to inoculation at 22 days after birth with the antigen showed reduced locomotion.Juvenile resting metabolic rate was not affected by early endotoxin exposure.These results suggest that the magnitude of O.degus responses would not change with age.We discuss whether the lack of effect of the response on body mass or body condition is caused by environmental variables or by the precocial characteristics of O.degus.

关键词： acute phase response ecoimmunology lipopolysaccharide precocial sickness behavior

Nonlinear numerical assessment of the seismic response of hillside RC buildings

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2021年第2期20卷 423-440页

作者： Miguel A.Gómez Edgar Giovanny Díaz-Segura Juan Carlos Vielma Civil Engineering School Pontificia Universidad Católica de ValparaísoValparaíso 2340000Chile

Major damage has been reported in hilly areas after major earthquakes,primarily because of two special conditions:the variation in the seismic ground motion due to the inclined ground surface and the irregularities caused by a stepped base level in the structure.The aim of this study is to evaluate possible differences in the responses of chilean hillside buildings through numerical linear-elastic and nonlinear analyses.In the first step,a set of response-spectrum analyses were performed on four simplified 2D structures with mean base inclination angles of 0°,15°,30°,and 45°.The structures were designed to comply with chilean seismic codes and standards,and the primary response parameters were compared.To assess the seismic performance of the buildings,nonlinear static(pushover)and dynamic(time-history)analyses were performed with SeismoStruct software.Pushover analyses were used to compare the nonlinear response at the maximum roof displacement and the damage patterns.Time-history analyses were performed to assess the nonlinear dynamic response of the structures subjected to seismic ground motions modified by topographic effects.To consider the topographic modification,acceleration records were obtained from numerical models of soil,which were calculated using the rock acceleration record of the Mw 8.01985 chilean earthquake.Minor differences in the structure responses(roof displacements and maximum element forces and moments)were caused by the topographic effects in the seismic input motion,with the highly predominant ones being the differences caused by the step-back configuration at the base of the structures.High concentrations of shear forces in short walls were observed,corresponding to the walls located in the upper zone of the foundation system.The response of the structures with higher angles was observed to be more prone to fragile failures due to the accumulation of shear forces.Even though hillside buildings gain stiffness in the lower stories,resulting in lower design roof displacement,maximum roof

关键词： topographic effect hillside buildings nonlinear analyses shear-wall buildings

Insights on the crosstalk between dendritic cells and helper T cells in novel genetic etiology for mendelian susceptible mycobacterial disease

在线全文

学校读者我要写书评

暂无评论

Cellular & Molecular Immunology 2018年第12期15卷 1091-1094页

作者： Emma Rey-Jurado Magdalena S.Pizarro-Ortega Alexis M.Kalergis Millennium Institute on Immunology and Immunotherapy Departamento de Genética Molecular y MicrobiologíaFacultad de Ciencias BiológicasPontificia Universidad Católica de ChileSantiago 8330644Chile departamento de Endocrinología Facultad de MedicinaPontificia Universidad Católica de ChileSantiago 8330644Chile

Mendelian susceptibility to mycobacterial disease(MSMD)is an inherited predisposition to infections by Bacille-Calmette Guérin(BCG)vaccine or by environmental mycobacteria.The etiology of MSMD has been associated with up to nineteen different genetic mutations in interferon(IFN)-γ-related genes.1 Although mycobacteria susceptibility-associated genetic mutations are rare in the population,their diagnosis is crucial for an efficient and timely treatment.Kong et al.2 have recently described an autosomal recessive deficiency in the signal peptidase-like 2 A(SPPL2-a)as a new genetic etiology for MSMD in three patients that had suffered BCG dissemination disease.

关键词： mendelian susceptibility to mycobacterial disease SPPL2a deficiency cDC2 mycobacterial-specific priming IFN-γ

Experimental and Numerical Analysis of a PCM-Integrated Roof for Higher Thermal Performance of Buildings

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Thermal Science 2024年第2期33卷 522-536页

作者： SIMON François RUIZ-VALERO Letzai GIRARD Aymeric GALLEGUILLOS Hector Centro de desarrollo Urbano Sustentable(CEdeUS) Pontificia Universidad Católica de Chile7500000SantiagoChile Facultad de Ciencias e Ingeniería Pontificia Universidad Católica Madre y Maestra(PUCMM)10103Santo DomingoDominican Republic LMGC IMT Mines AlesUniv MontpellierCNRS30100AlèsFrance Facultad de Ingeniería y Ciencias Universidad Adolfo Ibañez2520000Viña del MarChile Centro de desarrollo Energético Antofagasta(CdeA) Universidad de Antofagasta1240000AntofagastaChile

Phase change materials(PCMs) designate materials able to store latent heat.PCMs change state from solid to liquid over a defined temperature range.This process is reversible and can be used for thermo-technical purposes.The present paper aims to study the thermal performance of an inorganic eutectic PCM integrated into the rooftop slab of a test room and analyze its potential for building thermal management.The experiment is conducted in two test rooms in Antofagasta(chile) during summer,fall,and winter.The PCM is integrated into the rooftop of the first test room,while the roof panel of the second room is a sealed air cavity.The work introduces a numerical model,which is built using the finite difference method and used to simulate the rooms' thermal behavior.Several thermal simulations of the PCM room are performed for other chilean locations to evaluate and compare the capability of the PCM panel to store latent heat thermal energy in different climates.Results show that the indoor temperature of the PCM room in Antofagasta varies only 21.1℃±10.6℃,while the one of the air-panel room varies 28.3℃±18.5℃.Under the experiment's conditions,the PCM room's indoor temperature observes smoother diurnal fluctuations,with lower maximum and higher minimum indoor temperatures than that of the air-panel room.Thermal simulations in other cities show that the PCM panel has a better thermal performance during winter,as it helps to maintain or increase the room temperature by some degrees to reach comfort temperatures.This demonstrates that the implementation of such PCM in the building envelope can effectively reduce space heating and cooling needs,and improve indoor thermal comfort in different climates of chile.

关键词： phase change material thermal energy storage building space heating and cooling energy efficiency designbuilder

Numerical modeling of cracking pattern's influence on the dynamic response of thickened tailings disposals: a periodic approach

在线全文

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2018年第1期17卷 179-190页

作者： Gabriel Ferrer Esteban Sáez Christian Ledezma School of Engineering Pontificia Universidad Católica de Chile National Research Center for Integrated Natural Disaster Management

Copper production is an essential component of the chilean economy. During the extraction process of copper, large quantities of waste materials（tailings） are produced, which are typically stored in large tailing ponds. Thickened Tailings Disposal（TTD） is an alternative to conventional tailings ponds. In TTD, a considerable amount of water is extracted from the tailings before their deposition. Once a thickened tailings layer is deposited, it loses water and it shrinks, forming a relatively regular structure of tailings blocks with vertical cracks in between, which are then filled up with ＂fresh＂ tailings once the new upper layer is deposited. The dynamic response of a representative column of this complex structure made out of tailings blocks with softer material in between was analyzed using a periodic half-space finite element model. The tailings＇ behavior was modeled using an elasto-plastic multi-yielding constitutive model, and chilean earthquake records were used for the seismic analyses. Special attention was given to the liquefaction potential evaluation of TTD.

关键词： Thickened tailings Liquefaction Periodic modeling

Loneliness in Older chilean People: Importance of Family Dysfunction and depression

在线全文

学校读者我要写书评

暂无评论

International Journal of Mental Health Promotion 2021年第1期23卷 99-109页

作者： Marcela Carrasco MBeatriz Fernández Emma Alexander MSoledad Herrera School of Medicine Faculty of MedicinePontificia Universidad Católica de ChileMember of“Centro UC Estudios de Vejez y Envejecimiento”Centre for the Study of AgeingSantiago8330033Chile Institute of Sociology Pontificia Universidad Católica de ChileMember of“Centro UC Estudios de Vejez y Envejecimiento”Centre for the Study of AgeingSantiago7820436Chile School of Medicine Facultad de MedicinaPontificia Universidad Católica de ChileSantiago8330033Chile

Loneliness is considered a public health problem that negatively affects wellbeing,especially in the older population.In Latin-American countries,most of the older population live with their family.Although this is thought to diminish feelings of loneliness,there is scarce data to support this.The objective of this study is to determine the prevalence of loneliness and evaluate its association with objective social networks,family functioning and perception of social support,in a sample of older people from Santiago,chile.A survey was conducted of a representative sample of community older people(60–97 years)from Santiago,chile,using the UCLA abbreviated scale of loneliness.Logistic regression was performed to test the variables related to the loneliness of older people.A total of 1,217 older people were interviewed.88%were living with at least one person at home and 92%had living children.Using the UCLA abbreviated scale,45%were found to perceive feelings of loneliness at least some of the time.Logistic regression showed significant association between loneliness and family dysfunction;depressive symptoms;living alone;not having a partner(widowed,separated or single);having little contact with relatives and friends;feeling a lack of social support;and sensation of poor self-efficacy.Loneliness is a prevalent public health problem in this older Latin-American community.Living accompanied does not protect against loneliness,particularly in vulnerable groups such as those with depression,or when there are family conﬂicts.The high prevalence of loneliness strongly conveys the need for public health policies to address loneliness in older people.

关键词： Ageing family relations loneliness social support

Optimal length of triple therapy for H pylori eradication in a population with high prevalence of infection in chile

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2007年第21期13卷 2967-2972页

作者： Arnoldo Riquelme Alejandro Soza Cesar Pedreros Andrea Bustamante Felipe Valenzuela Francisco Otarola Eduardo Abbott Marco Arellano Brenda Medina Alejandro Pattillo Douglas Greig Marco Arrese Antonio Rollan department of Gastroenterology Pontificia Universidad Católica de Chile Hospital de Urgencia Asistencia Pública SantiagoChile department of Internal Medicine Pontificia Universidad Católica de Chile

AIM:To compare the efficacy of 7-d versus 14-d triple therapy for the treatment of H pylori infection in chile,with a prevalence of 73% in general population. METHODS:H pylori-infected patients diagnosed by rapid urease test,with non-ulcer dyspepsia or peptic ulcer disease were randomized to receive omeprazole 20 mg bid,amoxicillin 1 g bid,and clarithromycin 500 mg bid for 7 (OAC7) or 14 (OAC14) d. Primary outcome was eradication rate 6 wk after the treatment. Subgroup analysis was carried out considering the eradication rate among patients with or without peptic ulcer disease and eradication rate among smokers or non-smokers. RESULTS:One hundred and thirty-one patients were randomized to OAC7 (n = 69) or OAC14 (n = 62). The overall eradication rate (intention-to-treat) was 78.3% in OAC7 and 85.5% in OAC14 groups,without a significant difference (P =0.37). No significant difference in the eradication rate was found among the patients with peptic ulcer disease (n = 31) between the OAC7 group (85.7%) and OAC14 group (87.5%). However,smokers had an obviously lower eradication rate compared to non-smokers,particularly in the OAC7 group (57.1% in smokers vs 83.6% in non-smokers; P = 0.06). Adverse effects rate were similar between both groups. CONCLUSION:Short-term efficacy of triple therapy with OAC for 7 d is comparable to 14 d in this high-prevalence population. Longer follow-up,and studies focused to some subgroups of patients (smokers and non-ulcerpatients) are necessary to support widespread use of 7-d instead of 10-14-d triple therapy in a developing country like chile.

关键词：智利幽门螺杆菌病抗生素治疗疗程

Takotsubo syndrome-different presentations for a single disease: A case report and review of literature

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Cardiology 2018年第10期10卷 187-190页

作者： Alberto Fuensalida Maurice Cortés Luigi Gabrielli Manuel Méndez Alejandro Martínez Gonzalo Martínez Division of Cardiovascular Diseases Pontificia Universidad Católica de Chile

We report three cases of Takotsubo syndrome(TS) with atypical myocardial involvement. All three cases were triggered by physical or mental stress, resulting in transient myocardial compromise. However, the clinical presentation, localization and extent of myocardial damage varied in each case, ranging from low-risk acute chest pain to cardiogenic shock with low ejection fraction and dynamic obstruction of the left ventricular outflow tract. These cases outline the range of possible presentations of this rare entity and illustrate atypical forms of TS.

关键词： Coronary angiography Acute coronary syndrome Stress cardiomyopathy Takotsubo syndrome