Universidad Autónoma De Chile
Recent publications
Water contamination due to soluble synthetic dyes has serious concerns. Membrane-based wastewater treatments are emerging as a preferred choice for removing dyes from water. Poly(vinylidene fluoride) (PVDF)-based nanomembranes have gained much popularity due to their favorable features. This review explores the application of PVDF-based nanomembranes in synthetic dye removal through various treatments. Different fabrication methods to obtain high performance PVDF-based nanomembranes were discussed under surface coating and blending methods. Studies related to use of PVDF-based nanomembranes in adsorption, filtration, catalysis (oxidant activation, ozonation, Fenton process and photocatalysis) and membrane distillation have been elaborately discussed. Nanomaterials including metal compounds, metals, (synthetic/bio)polymers, metal organic frameworks, carbon materials and their composites were incorporated in PVDF membrane to enhance its performance. The advantages and limitations of incorporating nanomaterials in PVDF-based membranes have been highlighted. The influence of nanomaterials on the surface features, mechanical strength, hydrophilicity, crystallinity and catalytic ability of PVDF membrane was discussed. The conclusion of this literature review was given along with future research.
The subject of water contamination and how it gets defiled to the society and humans is confabulating from the past decades. Phenolic compounds widely exist in the water sources and it is emergent to determine the toxicity in natural and drinking water, because it is hazardous to the humans. Among these compounds, catechol has sought a strong concern because of its rapid occurrence in nature and its potential toxicity to humans. The present work aims to develop an effective electrochemical sensing of catechol using mesoporous structure of Fe3O4-TiO2 decorated on glassy carbon (GC) electrode. The creation of pure TiO2 using the sol-gel technique was the first step in the synthesis protocol for binary nanocomposite, which was then followed by the loading of Fe3O4 nanoparticles on the surface of TiO2 using the thermal decomposition method. The resultant Fe3O4-TiO2 based nanocomposite exhibited mesoporous structure and the cavities were occupied with highly active magnetite nanoparticles (Fe3O4) with high specific surface area (90.63 m2/g). When compared to pure TiO2, catechol showed a more prominent electrochemical response for Fe3O4-TiO2, with a significant increase in anodic peak current at a lower oxidation potential (0.387 V) with a detection limit of 45 μM. Therefore, the prepared magnetite binary nanocomposite can serve as an efficient electroactive material for sensing of catechol, which could also act as a promising electrocatalyst for various electrocatalytic applications.
Objectives: The two aims of this systematic review and meta-analysis were to(1) analyze the effect of exercise on chemotherapy-induced peripheral neuropathy (CIPN) severity and(2) determine the best type of exercise for the management of CIPN. Methods: We systematically searched the MEDLINE, WOS, Sportdiscus, Scopus and Cochrane databases from inception to December 2020 for experimental studies addressing the effect of exercise on CIPN severity, as measured by symptom severity(SSS) and peripheral deep sensitivity(PDS). The DerSimonian and Laird method was used to compute pooled estimates of the standardized mean differences (SMDs) and its respective 95% confidence intervals(CIs). Subgroup analyses were performed based on the types of exercise and the frequency and length of the interventions. Results: Thirteen studies were included in this meta-analysis. In the analyses comparing exercise interventions versus controls, there was an improvement in the SSS(SMD=-0.21; 95%CI:-0.40 to -0.01; %change:-20.34%) and the PDS(SMD=0.49; 95% CI:0.06 to 0.91; %change:31.64%) in favor of the intervention group. In the pre-post analyses, there was an improvement in the SSS (SMD=-0.72; 95% CI:-1.10 to -0.34; %change:-15.65%) and the PDS(SMD=0.47; 95% CI: 0.15 to 0.79; %change:18.98%). Conclusions: This meta-analysis provides an overview of the evidence supporting exercise as a suitable intervention to reduce the severity of CIPN by reducing the severity of the symptoms and the peripheral deep sensitivity among patients with cancer or cancer survivors. Furthermore, sensoriomotor training and mind-body exercises appear to be more effective in reducing symptom severity, and active nerve-specific exercises and mind-body exercises seem to be more effective in improving peripheral deep sensitivity.
Objective Arterial stiffness is an early and detectable marker of vascular changes leading to atherosclerotic cardiovascular disease (ACVD). Our objective was to compare the effectiveness of different types of exercise in reducing arterial stiffness in children and adolescents. Design A systematic review and network meta-analysis (NMA) was conducted including experimental studies reporting the effects of exercise interventions on pulse wave velocity (PWV) in children and adolescents. Data sources Cochrane Central Register of Controlled Trials, EMBASE (via Scopus), PubMed (via Medline) and Web of Science from database inception to 25 March 2022. Eligibility criteria Experimental studies reporting the effects of exercise interventions on PWV in children and adolescents. Results Fourteen studies were included in the NMA, all of them were randomised controlled trials except one quasi-experimental study, with an overall risk of bias of some concern. Regarding PWV reduction, all exercise modalities were more effective than control, with standardised mean difference ranging from −1.93 (95% CI: −2.84 to –1.02) and −1.11 (95% CI: −2.01 to –0.21) for aerobic exercise and high intensity interval training (HIIT), respectively, to −0.59 (95% CI: −1.39 to 0.22) for combined exercise. Only sensorimotor training was not superior to the control group 0.11 (95% CI: −1.10 to 1.32). Conclusion Our results support that exercise interventions, especially aerobic exercise or HIIT, can improve arterial stiffness at early ages. The potential to address ACVD early and mitigate long-term consequences via exercise interventions in children and adolescents with higher arterial stiffness requires further investigation. PROSPERO registration number CRD42022322536.
The topic of this Special Issue, “Energy Security and the Transition toward Green Energy Production”, acquired an uncomfortable timeliness while it was still in progress [...]
Background Although evidence suggests that ultra-processed food (UPF) consumption may trigger addictive behaviors, the association between UPF intake and psychoactive substances remains unclear among adolescents, a group especially vulnerable to addiction and its potentially harmful effects on health. Objective To analyze the association between the consumption of UPF and alcohol, tobacco, and illicit drugs in adolescent students. Method This cross-sectional study analyzed data from the National School-Based Health Survey (PeNSE 2019), which collected information from a representative population-based sample of students aged 13–17 years in Brazil. UPF consumption was self-reported in a 24-h recall. Lifetime and use of alcohol, tobacco, and illicit drugs in the last month were also reported. Multinomial logistic regression models estimated the relative risk ratios (RRR) (95% confidence intervals – CI) because the outcome variables comprised four categories representing varying frequencies of use of psychoactive substances. Results The mean ± standard error number of different UPF consumed among the 95,074 adolescents included (52.3% girls) was 4.37 ± 0.02. The results from adjusted models revealed that, compared to those who reported low UPF consumption (1st tertile), those who consumed more UPF (3rd tertile) were more likely to report frequent (≥ 3 days in the last month) drinking of alcoholic beverages (RRR = 2.19; 95% CI: 1.87, 2.56), illicit drugs (RRR = 2.22; 95% CI: 1.87, 2.85) and occasional (one or two days in the last month) smoking (RRR = 1.30; 95% CI: 1.05, 1.60). Conclusions UPF consumption was associated with alcohol, tobacco, and illicit drug use in a national sample of Brazilian adolescents.
The hyperthermal dynamics and kinetics of the title reaction, which plays an important role in hypersonic chemistry for atmospheric entry vehicles, are investigated using quasi-classical trajectory methods on a recently developed ground electronic state potential energy surface. The dynamics calculations indicated that the reaction follows a complex-forming mechanism, despite its large endoergicity. The calculated differential cross section is forward-backward symmetric, consistent with a long-lived reaction intermediate supported by the NCN potential well. The lifetime of the reaction complex is sufficiently long that the vibrational distribution of the CN product can be predicted by the phase space theory. The calculated vibrational state specific and thermal rate coefficients follow the Arrhenius behavior, and the agreement with existing low-temperature experimental thermal rate coefficients is satisfactory. Extrapolations to high temperatures relevant to hypersonic conditions are provided.
BACKGROUND: Polyphenols are a group of compounds distributed in foods of plant origin and have been considered as effective protective agents against chronic diseases. To date, there are limited data on polyphenol intakes worldwide. OBJECTIVE: The aim of the present study was to describe the intake of polyphenols and their subclasses in Chile based on data extracted from the National Food Consumption Survey 2010 –2012 (ENCA). METHODS: A total of 3658 participants were selected from whom information on food consumption frequency, anthropometric, clinical, socioeconomic and lifestyle variables were available. RESULTS: The mean intake value of total polyphenols was 979.5 + 695.5 mg/day. A higher intake was observed in men than in women. In addition, among adults, there is a higher consumption in the South macrozone. An increase in the intake of total polyphenols was evidenced when the population belonged to the high socioeconomic stratum, and the most consumed types were flavonoids and phenolic acids. CONCLUSION: Due to the growing evidence that shows a protective effect of polyphenol consumption, it is necessary to carry out more research related to the consumption of these compounds, promoting the consumption of foods that provide them and thus contributing to improve the current epidemiological.
Social media sites have become an important tool for socialisation and political engagement, particularly in the case of young people. This article aims to explore the relationship between, on the one hand, the consumption and political use of social media and (a) the sense of political efficacy and (b) the building of social capital. The study presented focuses on university students from Chile, Spain and Mexico, who were surveyed during 2017–2018. A quantitative methodology combining univariate, bivariate and multivariate data analysis was used, with the results revealing that the sense of political efficacy is influenced by the political use of social media, while social capital is influenced by both the consumption of social media and the political use made thereof.
A good diagnostic test should show different behavior on both the positive and the negative populations. However, this is not enough for having a good classification system. The binary classification problem is a complex task, which implies to define decision criteria. The knowledge of the level of dissimilarity between the two involved distributions is not enough. We also have to know how to define those decision criteria. The length of the receiver-operating characteristic curve has been proposed as an index of the optimal discriminatory capacity of a biomarker. It is related not with the actual but with the optimal classification capacity of the considered diagnostic test. One particularity of this index is that its estimation should be based on parametric or smoothed models. We explore here the behavior of a kernel density estimator-based approximation for estimating the length of the receiver-operating characteristic curve. We prove the asymptotic distribution of the resulting statistic, propose a parametric bootstrap algorithm for confidence intervals construction, discuss the role that the bandwidth parameter plays in the quality of the provided estimations and, via Monte Carlo simulations, study its finite-sample behavior considering four different criteria for the bandwidth selection. The practical use of the length of the receiver-operating characteristic curve is illustrated through two real-world examples.
Background: Music festivals are part of the cultural industry, and have become an ever-growing phenomenon. It is essential for organisers to identify whether the marketing strategies implemented are positive and effective in generating a competitive advantage. The aim of this study is to identify the elements that make up the brand equity of an emerging music festival, and to find out whether the overall brand equity determines the satisfaction and subsequent behaviours of festival-goers. Methods: Quantitative research was used by conducting an ad hoc structured survey during the development of a live music festival in May 2022. The questionnaire collects information about dimensions that make up the global brand value and how they influence satisfaction and behavioural intentions, consisting of a total of 33 indicators.; Results: Awareness, perceived quality, and loyalty are the most influential dimensions in shaping the brand of a festival. There is a correlation between the overall brand value and the satisfaction of the attendees, and that the latter influences the subsequent loyalty and recommendation of the event. Conclusions: The causal relationships between the dimensions of brand equity and overall brand equity are shown, where three of the four hypotheses are accepted. Similarly, the three hypotheses related to the influence of overall brand image and behavioural intentions are also accepted.
Here, we present evidence that the D2h M2C50/2+ (M = Li-K, Be-Ca, Al-In, and Zn) species comprises planar hexacoordinate carbon (phC) structures that exhibit four covalent and two electrostatic interactions. These findings have been made possible using evolutionary methods for exploring the potential energy surface (AUTOMATON program) and the Interacting Quantum Atoms (IQA) methodology, which support the observed bonding interactions. It is worth noting, however, that these structures are not the global minimum. Nonetheless, incorporating two cyclopentadienyl anion ligands (Cp) into the CaC52+ system has enhanced the relative stability of the phC isomer. Moreover, cycloparaphenylene ([8]CPP) provides system protection and kinetic stability. These results indicate that using appropriate ligands presents a promising approach for expanding the chemistry of phC species.
This paper examines the short- and long-term effects of lax economic policy in Chile during the COVID-19 pandemic and discusses whether they promoted or inhibited sustainable economic growth and development. The case of Chile is worth studying because it straightforwardly describes the effects of passive and active economic policy on the economy. It is argued that the active or lax economic policy generated a short-term boom period and a long-term recessive environment. Lax economic policy in Chile distorted the price system and the intertemporal allocation of resources, stimulating consumption and indebtedness. Investments became less capital intensive, stagnating labor productivity and reducing growth and development. Regardless of external factors, the research shows that the recession of the Chilean economy emerged from lax economic policies and institutional uncertainty. These findings recognize the causes of the recessive environment of emerging economies, offering new insights into promoting sustainable economic growth and development post-crisis.
The generalized receiver-operating characteristic, gROC, curve considers the classification ability of diagnostic tests when both larger and lower values of the marker are associated with higher probabilities of being positive. Its empirical estimation implies to select the best classification subsets among those satisfying particular condition. Both strong and weak consistency have already been proved. However, using the same data for both to select the classification subsets and to calculate its gROC curve leads to an over-optimistic estimate of the real performance of the diagnostic criteria on future samples. In this work, the bias of the empirical gROC curve estimator is explored through Monte Carlo simulations. Besides, two cross-validation based algorithms are proposed for reducing the overfitting. The practical application of the proposed algorithms is illustrated through the analysis of a real-world dataset. Simulation results suggest that the empirical gROC curve estimator returns optimistic approximations, especially, in situations in which the diagnostic capacity of the marker is poor and the sample size is small. The new proposed algorithms improve the estimation of the actual diagnostic test accuracy, and get almost unbiased gAUCs in most of the considered scenarios. However, the cross-validation based algorithms reported larger L1\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$L_1$$\end{document}-errors than the standard empirical estimators, and increment the computational cost of the procedures. As online supplementary material, this manuscript includes an R function which wraps up the implemented routines.
An anaerobic, Gram-staining-negative, rod-shaped, Fe(III)-reducing strain, designated SG189T, was isolated from paddy soil in Fujian Province, China. Growth occurred at 20–35 ℃ (optimum 30 ℃), pH 6.5–8.0 (optimum 7.0) and 0–0.2% (w/v) NaCl (optimum 0%). The strain SG189T showed the highest 16S rRNA sequences similarities to the type strains of Geothrix fermentans DSM 14018T (98.9%), “Geothrix terrae” SG184T (99.0%) and “Geothrix alkalitolerans” SG263T (99.3%). ANI and dDDH values between strain SG189T and the most closely related Geothrix species were 86.5–87.1% and 31.5–32.9%, which lower than the cut-off values (ANI 95–96% and dDDH 70%) for prokaryotic species delineation. Further, genome-based phylogenomic trees constructed using 81 core genes (UBCG2) and 120 conserved genes (GTDB) showed that strain SG189T formed a clade with members of the genus Geothrix. The menaquinone was shown to be MK-8, and the major fatty acids were iso-C15:0 and iso-C13:0 3OH. The genomic DNA G + C content was 68.2%. Additionally, we found that strain SG189T possessed ability to reduce ferric iron, and strain SG189T could reduce 10 mM of ferric citrate in 10 days with lactate as the sole electron donor. Based on the observed physiological and biochemical properties, chemotaxonomic characteristics, ANI and dDDH values, SG189T represents a novel species of the genus Geothrix, for which the name Geothrix oryzisoli sp. nov. is proposed. The type strain is SG189T (= GDMCC 1.3408T = JCM 39324T).
Background Alzheimer’s disease (AD) is characterized by a polyetiological origin. Despite the global burden of AD and the advances made in AD drug research and development, the cure of the disease remains elusive, since any developed drug has demonstrated effectiveness to cure AD. Strikingly, an increasing number of studies indicate a linkage between AD and type 2 diabetes mellitus (T2DM), as both diseases share some common pathophysiological features. In fact, β-secretase (BACE1) and acetylcholinesterase (AChE), two enzymes involved in both conditions, have been considered promising targets for both pathologies. In this regard, due to the multifactorial origin of these diseases, current research efforts are focusing on the development of multi-target drugs as a very promising option to derive effective treatments for both conditions. In the present study, we evaluated the effect of rhein-huprine hybrid (RHE-HUP), a synthesized BACE1 and AChE inhibitor, both considered key factors not only in AD but also in metabolic pathologies. Thus, the aim of this study is to evaluate the effects of this compound in APP/PS1 female mice, a well-established familial AD mouse model, challenged by high-fat diet (HFD) consumption to concomitantly simulate a T2DM-like condition. Results Intraperitoneal treatment with RHE-HUP in APP/PS1 mice for 4 weeks reduced the main hallmarks of AD, including Tau hyperphosphorylation, Aβ 42 peptide levels and plaque formation. Moreover, we found a decreased inflammatory response together with an increase in different synaptic proteins, such as drebrin 1 (DBN1) or synaptophysin, and in neurotrophic factors, especially in BDNF levels, correlated with a recovery in the number of dendritic spines, which resulted in memory improvement. Notably, the improvement observed in this model can be attributed directly to a protein regulation at central level, since no peripheral modification of those alterations induced by HFD consumption was observed. Conclusions Our results suggest that RHE-HUP could be a new candidate for the treatment of AD, even for individuals with high risk due to peripheral metabolic disturbances, given its multi-target profile which allows for the improvement of some of the most important hallmarks of the disease.
Body image is a fundamental factor that influences a person’s self-image throughout life and at all stages of life. Self-perception of body image and body mass index may be related, as the way a person views him or herself can influence their eating behavior and level of physical activity, which in turn can affect their weight and BMI. The aim of this study is to find the association between body mass index, age, and body self-perception of university students, analyzing possible differences according to the gender of the students. In total, 312 students answered five sociodemographic questions in addition to the Multidimensional Body Self Relations Questionnaire, which consists of 45 questions grouped into four dimensions. Spearman’s Rho test was used to analyze the association between each of the Multidimensional Body Self Relations Questionnaire (MBSRQ) factors and body mass index (BMI). Statistical differences were found in dimension 3 (p < 0.01) of the MBSRQ questionnaire with respect to BMI in both sexes, and in dimension 1 (p < 0.01), a significant difference was found in female students. With the male gender, significant differences were found between age and BMI (0.04). Consequently, the sex to which the student belongs conditions his or her BMI with the self-perceived body image, so lines of action should be developed to improve self-image.
Researchers’ interest in finding practical applications for virtual reality (VR) and augmented reality (AR) technologies has increased as new devices have become cheaper and more accessible, being used in entertainment, healthcare, and rehabilitation fields, among others. This study aims to provide an overview of the current state of scientific literature related to VR, AR, and physical activity (PA). A bibliometric analysis of studies published between 1994 and 2022 was conducted using The Web of Science (WoS), applying the traditional bibliometric laws and using the VOSviewer software for data and metadata processing. The results revealed an exponential increase in scientific production between 2009 and 2021 (R2 = 94%). The United States (USA) was the country/region with the most relevant co-authorship networks (72 papers); the most prolific author was Kerstin Witte, and the most prominent was Richard Kulpa. The most productive journal’s core was composed of high-impact and open access journals. A great thematic diversity was found according to the most used keywords by the co-authors, highlighting concepts such as rehabilitation, cognition, training, and obesity. Then, the research related to this topic is in an exponential development phase, with great interest in the rehabilitation and sports sciences fields.
Aims The objective of this study was to describe and understand irregular migrants' (IMs') experiences of health disparities while living in informal settlements (ISs) during the COVID‐19 pandemic. Design Qualitative descriptive study. Methods Thirty‐four IMs originating from different African countries living in ISs took part in this study. Data were collected between January and March 2022 through three focus groups and 17 in‐depth interviews. Thematic analysis was used to analyse qualitative data with ATLAS.ti computer software. Results Three main themes emerged: (1) Extreme vulnerability: ISs and abuse; (2) Inequality in health treatment has increased during COVID‐19; and (3) The impact of COVID‐19 on the health of IMs: help from non‐governmental organizations and nurses. Conclusion Irregular migrants are at a higher risk of exposure to COVID‐19 due to their precarious living conditions, administrative situation and access to the health system. It is recommended that specific programmes be strengthened to improve health care for this population. Impact What problem did the study address? This study examines IMs' experiences of health disparities during the COVID‐19 pandemic. What were the main findings? IMs are at higher risk of exposure to COVID‐19 due to social, health, housing and work inequalities. Community health nurses alongside non‐governmental organizations have facilitated the implementation of measures to protect this population against COVID‐19. Where and on whom will the research have an impact? With the aim of improving care for IMs, strategies have been suggested for health institutions to address problems relating to accessing the health system, and to promote networking between non‐governmental organizations and community health nurses.
The dust continuum and molecular distributions observed on the sky plane always show irregular shapes of molecular clouds. However, it is hard to directly reproduce the observed distributions using symmetrical models. In this work, for the first time, we present a three-dimensional (3-D) gas-grain chemical simulation using an irregular 3-D density structure derived by the Abel inversion taking the starless core L1544 as an example. We found that most (∼70%) of the observed features (molecular distributions, peak positions and column density values of 16 species) can be reproduced directly. The previously reached conclusion of non-uniform illumination at C3H2 peak is confirmed as the contribution from the gas component with density of a few 104 cm−3 at distance of ∼3000–8000 au from the core center along the line of sight.
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847 members
Claudia Sandoval
  • Instituto de Ciencias Químicas Aplicadas
Pablo Contreras
  • Facultad de Derecho
Luis Morales-Quintana
  • Instituto de Ciencias Biomédicas
Rodrigo A Quintanilla
  • Laboratory of Neurodegenerative Diseases, Centro de Investigación Biomédica
Manuel Gidekel
  • Facultad de Ingeniería
Pedro de Valdivia 641, Providencia, Santiago, Chile
Head of institution
Dr. Teodoro Ribera Neumann
+56 02 2 303 6000