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Comparación del rendimiento de colágeno de tilapia “Oreochromis niloticus” roja, gris y la F1, a los 9 meses de cultivo
No full textEl objetivo de este estudio es comparar los rendimientos del colágeno de tilapia “Oreochromis niloticus” de tres líneas, de la Roja, Gris y la F1. Se utilizaron dos métodos de extracción para obtener colágeno soluble en ácido (ASC) y colágeno soluble en pepsina (PSC) de la piel de tilapia. El resultado del rendimiento de la piel según el peso corporal total fue de Roja: 4.22 ± 033, Gris: 3.66 ± 0.36 y F1: 4.35 ± 0.34%. Los rendimientos de colágeno fueron: porASC: Roja,19.04 ± 0.59; Gris, 20.06 ± 2.20; F1, 20.28 ± 186% y por PSC:Roja, 21.10 ± 1.59; Gris, 21.21 ± 1.14 y F1,21.10 ± 1.59 %. Los porcentajes de la hidroxiprolina fueron para ASC: Roja, 9.43; Gris, 9.81 y F1,9.04 % y PSC: Roja,10.64; Gris, 10.30 y F1,10.33 %. Los valores de absorbancia UV visible de los colágenos ASC y PSC, se encuentran en los rangos (210 a 240 nm) establecidos para las proteínas colágenas. La temperatura de desnaturalización del colágeno ASC (Roja,34 ºC; Gris, 31.9 ºC y F1,34.9 ºC), siendo ligeramente mayor al de PSC (Roja, 31.1 ºC; Gris, 30 ºC y F1, 31.1 ºC). El perfil SDS-PAGE mostró que todas las muestras de colágeno ASC y PSC contenían dos cadenas α1 y una cadena α2, característico del colágeno tipo I (α1: 117.72 kDa, α2: 111.92kDa). los resultados sugieren que la piel de tilapia Roja, Gris y F1 son una gran alternativa al colágeno de mamífero.Fondo Nacional de Desarrollo Científico y Tecnológico - Fondecy
Analysis of the physical and photoelectrochemical properties of c-Si(p)/a-SiC:H(p) photocathodes for solar water splitting
No full textThis research was funded by FONDECYT (National Fund for Scientific, Technological Development and Technological Innovation) under the agreement 147-2017. The author M Mejia has been supported by the CONCYTEC Peru (National Council for Science, Technology and Technological Innovation) doctoral scholarship under the Contract Number 236-2015-FONDECYT as well as by the PUCP vicechancellorship for research (VRI, Project No. CAP-2019-3-0041/702). The authors would like to thank the Katholischer Akademischer Auslander-Dienst institution (KAAD) for the short-term grants given to conduct research internships in the Technische Universitat Ilmenau (TU Ilmenau). Finally, the authors would like to thank the German Research Foundation (DFG) (DFG-Gz: INST 273/56-1 FUGG) and the Materials Characterization Center (CAM) at PUCP, for the financial support to conduct the characterization experiments.The photoelectrochemical (PEC) properties of sputtered aluminum doped hydrogenated amorphous silicon carbide thin films grown on p-type crystalline silicon substrates were investigated in 1 M H2SO4<i solution under chopped light illumination. Optical and structural properties of the top absorber layer were systematically assessed after post-deposition isochronical annealing treatments. Samples exhibited a noticeable improvement of the opto-electronic properties after thermal treatments. In addition, an abrupt enhancement of the photocurrent was observed reaching a saturation value of 17 mA cm(-2) at -1.75 V vs. Ag/AgCl (3.5 M KCl). In this research we propose that this enhancement effect is associated to a charge transfer kinetic mechanism influenced by surface states and the p-type substrate. The latter most likely due to the space charge region extending beyond the absorber layer reaching the substrate. Current density-potential and electrochemical impedance spectroscopy measurements in dark revealed a reduction of the SiO2 native layer at cathodic potentials higher than -1 V vs. Ag/AgCl (3.5 M KCl), which contributes to the high charge transfer kinetic of the system. We believe that these results will contribute to understand the substrate influence in the PEC performance of top absorber layers in multilayer structures for solar water splitting.Fondo Nacional de Desarrollo Científico y Tecnológico - Fondecy
Analytical and numerical modeling for the assessment of CO2 storage in the Parinas geological formation - Talara, Peru
No full textThis project was funded by the Consejo Nacional de Ciencia, Tec-nologia e Innovacion Tecnologica (CONCYTEC) of the Peruvian gov-ernment within the framework of the 159-2017-FONDECYT Agreement. The authors would like to thank Perupetro for providing valuable information used in this work.This research evaluates the CO2 storage capacity of the Parinas Formation belonging to the Talara basin in Peru through analytical modeling based on mass balance equations and numerical modeling using IMEX CMG. Parinas Formation has several depleted hydrocarbon reservoirs that presents favorable conditions for CO2 geological storage. It has an average porosity of 17.6% and a permeability of 640 mD in the horizontal direction consisting of sandstones with interspersed lutites layers. The study evaluates the depleted Bellavista oil deposits involving CO2 storage capacity estimation with CO2 and reservoir fluid (oil and water) interaction. It involves numerical modeling based on the reservoirs properties and CO2 injection simulation not exceeding the fracture pressure of the reservoir rock. This approach is the first one carried out in Peru and provides the chance to evaluate the CO2 storage capacity in a hydrocarbon reservoir in this part of the world, as a strategy to mitigate future global change impacts. The results indicate a storage capacity of 35.37 million tons of CO2, approximately. Besides, the sandstone reservoir of the Parinas geological formation has adequate characteristics to serve as a CO2 storage reservoir. C-30(+) pseudo component shows greater sensitivity in its properties (temperature and critical pressure) adjusting the fluid properties with the experimental data (saturation pressure, viscosity and minimum miscibility pressure).Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
CALLISTO facilities in Peru: spectrometer commissioning and observations of type III solar radio bursts
No full textThe Astrophysics Directorate of CONIDA has installed two radio spectrometer stations belonging to the e-CALLISTO network in Lima, Peru. Given their strategic location near the Equator, it is possible to observe the Sun evenly throughout the whole year. The receiver located at Pucusana, nearby the capital city of Lima, took data from October 2014 until August 2016 in the metric and decimetric bands looking for radio bursts. During this period, this e-CALLISTO detector was unique in its time-zone coverage. To asses the suitability of the sites and the performance of the antennas, we analyzed the radio ambient background and measured their radiation pattern and beamwidth. To demonstrate the capabilities of the facilities for studying solar dynamics in these radio frequencies, we have selected and analyzed type III Solar Radio Bursts. The study of this kind of burst helps to understand the electron beams traversing the solar corona and the solar atmospheric density. We have characterized the most common radio bursts with the following mean values: a negative drift rate of -25.8 +/- 3.7 MHz s(-1), a duration of 2.6 +/- 0.3 s and 35 MHz bandwidth in the frequency range of 114 to 174 MHz. In addition, for some events, it was possible to calculate a global frequency drift which on average was 0.4 +/- 0.1 MHz s(-1).J. R. appreciates the support from the Peruvian National Council for Science, Technology and Technological Innovation scholarship under Grant 23-2015-FONDECyT and thanks Fernando Valle's help in the installation of CALLISTO. J. B. thanks the Direccion de Gestion de la Investigacion (DGI - PUCP) for funding under Grant No. DGI-2019-3-0044. We thank the Air Force electronic laboratory SELEC for the tests done at their facilities and the Institute for Data Science FHNW Brugg/Windisch, Switzerland for providing data from the e-CALLISTO network. We also wish to thank C. Consolandi, F. Valle and S. della Torre for reading the manuscript and their useful suggestions. We specially thank C. Monstein for his help and suggestions in the analysis of the e-CALLISTO data and also for reading the manuscript
Diagnosis of Alzheimer's Disease in Developed and Developing Countries: Systematic Review and Meta-Analysis of Diagnostic Test Accuracy
No full textThis study was supported by the Consejo Nacional de Ciencia, Tecnologia e Innovacion y Tecnologia (CONCYTEC) and the Fondo Nacional de Desarrollo Cientifico, Tecnologico y de Innovacion Tecnologica de Peru (FONDECYT). Contract Nr. 24-2019. We would like to thank Dr. Maximo Rondon and Dra Karina Rosas and theVicerrectorado de investigacion for providing substantial support to the Laboratory of Genomics and Neurovascular Diseases to carry out this work.Background: The present systematic review and meta-analysis of diagnostic test accuracy summarizes the last three decades in advances on diagnosis of Alzheimer's disease (AD) in developed and developing countries. Objective: To determine the accuracy of biomarkers in diagnostic tools in AD, for example, cerebrospinal fluid, positron emission tomography (PET), and magnetic resonance imaging (MRI), etc. Methods: The authors searched PubMed for published studies from 1990 to April 2020 on AD diagnostic biomarkers. 84 published studies were pooled and analyzed in this meta-analysis and diagnostic accuracywas compared by summary receiver operating characteristic statistics. Results: Overall, 84 studies met the criteria and were included in a meta-analysis. For EEG, the sensitivity ranged from 67 to 98%, with a median of 80%, 95%CI [75, 91], tau-PET diagnosis sensitivity ranged from 76 to 97%, with a median of 94%, 95%CI [76, 97]; and MRI sensitivity ranged from 41 to 99%, with a median of 84%, 95%CI [81, 87]. Our results showed that tau-PET diagnosis had higher performance as compared to other diagnostic methods in this meta-analysis. Conclusion: Our findings showed an important discrepancy in diagnostic data for AD between developed and developing countries, which can impact global prevalence estimation and management of AD. Also, our analysis found a better performance for the tau-PET diagnostic over other methods to diagnose AD patients, but the expense of tau-PET scan seems to be the limiting factor in the diagnosis of AD in developing countries such as those found in Asia, Africa, and Latin America.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Estimation of genetic parameters for four Peruvian guinea pig lines
No full textCONCYTEC co-funded this research through its project execution unit FONDECYT, as part of the project: 178-2015-FONDECYT - Doctorado en Ciencia Animal.This study aimed to estimate genetic parameters for four guinea pig lines of a crossbreeding scheme. Two paternal lines are selected for growth rate (P1) and feed conversion rate (P2), whereas two maternal lines are selected for growth rate of litter (M1) and litter size at birth (M2). The heritabilities and genetic correlations were estimated with animal linear models employing multivariate analyses with REML. The heritabilities for birth weight (BW) were 0.21 +/- 0.02 and 0.23 +/- 0.03 for P1 and P2, respectively, and for weaning weight (WW), the heritability was 0.28 +/- 0.03 for P2. The estimates for weight at 60 days of age (W60) were 0.34 +/- 0.01 and 0.47 +/- 0.04 for P1 and P2, respectively, and for partial feed conversion rate was 0.46 +/- 0.03 for P2. Heritabilities for litter weight at birth (LW) were 0.09 +/- 0.03 and 0.10 +/- 0.03 for P1 and M1, respectively. For litter weight at 10 days of age (LW10), the heritability was 0.15 +/- 0.03 for M1. Heritabilities for litter size (LS) were 0.17 +/- 0.03, 0.20 +/- 0.03 and 0.11 +/- 0.03, and for number of pups born alive (BA) were 0.09 +/- 0.03, 0.14 +/- 0.03 and 0.09 +/- 0.03 for P1, M1 and M2, respectively. Similarly, high genetic correlations were found between BW, WW and W60 and between LW, LS, LW10 and BA. The genetic correlation between BW direct and maternal was moderately negative (-0.24 +/- 0.10) for P1. These results show the genetic status for all four guinea pig lines, which is essential for the further improvement of the currently implemented breeding programme and also indicate an opportunity for genetic improvement.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Recurrence of Urinary Tract Infections due to Escherichia coli and Its Association with Antimicrobial Resistance
No full textJ.R. was supported by Fondo Nacional de Desarrollo Cientifico, Tecnologico y de Innovacion Tecnologica (FONDECYT-Peru) within the Proyecto de Mejoramiento y Ampliacion de los Servicios del Sistema Nacional de Ciencia, Tecnologia e Innovacion Tecnologica'' (contract: 08-2019-FONDECYT-BM-INC-INV).We analyzed the association between antibiotic resistance and recurrent urinary tract infection (rUTI) by Escherichia coli. Susceptibility levels to 14 antimicrobial agents and the presence of extended-spectrum beta-lactamases (ESBL) were established using MicroScan. Incidences of multidrug resistant (MDR), extensively drug resistant (XDR), and ESBL-producer isolates as well as rUTIs were estimated. The time to recurrence was established adjusted for number of antibiotic-resistant families and MDR as predictors of interest, respectively. Overall, 8,553 urinary tract infection (UTI) cases related to E. coli, including 963 rITU, were analyzed with levels of resistance >30% in all cases, except for amikacin, nitrofurantoin, and carbapenems. The incidence of rUTI was of 11.3%, being 46.5%, 24.3%, and 42.5% for MDR, XDR, and ESBLs, respectively. Bivariate analysis showed that rUTI was associated with age, gender, resistance to specific antimicrobials, MDR, and XDR. The number of antibiotic families tested as resistant, MDR, XDR, gender, and age were associated with time to recurrence when adjusted for number of antibiotic families, and MDR, gender, and age were related when adjusted for MDR. High rates of antibiotic resistance to the usual antibiotics was observed in E. coli causing UTI, with female sex, age, and antibiotic resistance being risk factors for the development of rUTI.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Synthesis and characterization of pure, two-qubit states encoded in path and polarization
No full textSome of the authors (D R A R P and J P M) acknowledge funding by FONDECYT through Grant 236-2015. This work was partially supported by the US Office of Naval Research Global (ONR, Award No. N62909-19-1-2148, Grant No. GRANT12853637).We have designed and experimentally put to test a protocol to synthesize and characterize pure, two-qubit states encoded in polarization and momentum (path) of light beams. Because these degrees of freedom are common to both classical and quantum light, it was possible to implement our protocol with classical light, thereby offering an advantageous and versatile testing ground. The experimental setup is robust and does not require state-dependent scheme modifications. We exhibited the capabilities of our protocol by generating three types of two-qubit states: Bell states, states with variable phases, and states with variable amplitudes.Fondo Nacional de Desarrollo Científico y Tecnológico - Fondecy
The dynamic cycle of bacterial translation initiation factor IF3
No full textInnovatePeru [382-PNICP-PIBA-2014 and 297INNOVATEPERU-EC-2016 to P.M.]; Fondo Nacional de Desarrollo Cientifico, Tecnologico y de Innovacion Tecnologica [154-2017-Fondecyt and 0362019-Fondecyt-BM-INC.INV to P.M.]; FIRB Futuro in Ricerca [RBFR130VS5 001 to A.F.]; Italian Ministero dell'Istruzione, dell'Universita e della Ricerca (to A.F.); Part of the work on structural dynamics of the ribosome was supported by Russian Science Foundation [17-1401416 to A.L.K.]. Funding for open access: Universidad Peruana de Ciencias Aplicadas (Exp-03).Initiation factor IF3 is an essential protein that enhances the fidelity and speed of bacterial mRNA translation initiation. Here, we describe the dynamic interplay between IF3 domains and their alternative binding sites using pre-steady state kinetics combined with molecular modelling of available structures of initiation complexes. Our results show that IF3 accommodates its domains at velocities ranging over two orders of magnitude, responding to the binding of each 30S ligand. IF1 and IF2 promote IF3 compaction and the movement of the C-terminal domain (IF3C) towards the P site. Concomitantly, the N-terminal domain (IF3N) creates a pocket ready to accept the initiator tRNA. Selection of the initiator tRNA is accompanied by a transient accommodation of IF3N towards the 30S platform. Decoding of the mRNA start codon displaces IF3C away from the P site and rate limits translation initiation. 70S initiation complex formation brings IF3 domains in close proximity to each other prior to dissociation and recycling of the factor for a new round of translation initiation. Altogether, our results describe the kinetic spectrum of IF3 movements and highlight functional transitions of the factor that ensure accurate mRNA translation initiation.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
A differential DNA methylome signature of pulmonary immune cells from individuals converting to latent tuberculosis infection
No full textWe would like to show our appreciation to the medical personnel at Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, for assistance in sample collections and analysis of QuantiFERON® TB-Gold Plus test. We thank the Bioinformatics and Expression Analysis core facility (BEA) at Karolinska Institute that preformed the sequencing analysis. We thank the Swedish National Infrastructure for Computing (SNIC) at National Supercomputing Centre (NSC), Linköping University for the computing systems enabling the data handling, partially funded by the Swedish Research Council through grant agreement No. 2018-05973. The work was supported by grants from the Swedish Research Council No. 2018-04246 and the Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica CONCYTEC and Cienciactiva No. 106-2018-FONDECYT. J.D is a postdoctoral fellow supported through the Medical Infection and Inflammation Center (MIIC) at Linköping University.Tuberculosis (TB), caused by Mycobacterium tuberculosis, spreads via aerosols and the first encounter with the immune system is with the pulmonary-resident immune cells. The role of epigenetic regulations in the immune cells is emerging and we have previously shown that macrophages capacity to kill M. tuberculosis is reflected in the DNA methylome. The aim of this study was to investigate epigenetic modifications in alveolar macrophages and T cells in a cohort of medical students with an increased risk of TB exposure, longitudinally. DNA methylome analysis revealed that a unique DNA methylation profile was present in healthy subjects who later developed latent TB during the study. The profile was reflected in a different overall DNA methylation distribution as well as a distinct set of differentially methylated genes (DMGs). The DMGs were over-represented in pathways related to metabolic reprogramming of macrophages and T cell migration and IFN-? production, pathways previously reported important in TB control. In conclusion, we identified a unique DNA methylation signature in individuals, with no peripheral immune response to M. tuberculosis antigen who later developed latent TB. Together the study suggests that the DNA methylation status of pulmonary immune cells can reveal who will develop latent TB infection. © 2021, The Author(s).Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte