On the distribution of an effective channel estimator for multi-cell massive MIMO

Accurate channel estimation is of utmost importance for massive MIMO systems to provide significant improvements in spectral and energy efficiency. In this work, we present a study on the distribution of a simple but yet effective and practical channel estimator for multi-cell massive MIMO systems suffering from pilot-contamination. The proposed channel estimator performs well under moderate to aggressive pilot contamination scenarios without previous knowledge of the inter-cell large-scale channel coefficients and noise power, asymptotically approximating the performance of the linear MMSE estimator as the number of antennas increases. We prove that the distribution of the proposed channel estimator can be accurately approximated by the circularly-symmetric complex normal distribution, when the number of antennas, M, deployed at the base station is greater than 10

Viral hepatitis and the immunological response: a review

Introduction: In Brazil, viral hepatitis is infectious disease of compulsory notification and is considered a serious public health problem. Infections with A, B, C, D or E viruses trigger the activation of immune system molecules and cells at the level of innate and acquired immunity. Objective: The present study aimed to review the knowledge about viral hepatitis and the immune system's performance against these infections. Methods: This is a literature overview from academic books and scientific articles available in the Scientific Electronic Library Online, US National Library of Medicine National Institutes of Health and Google Scholar databases. Having as key words hepatitis A, hepatitis B, hepatitis C, hepatitis D, hepatitis E and immune system. The relevant articles corresponding to the period between 1974 and 2017 were selected. Development: Viral hepatitis is characterized by inflammation in liver cells caused by groups of viruses that have hepatotropism in common. The diagnosis is made through serological methods and molecular biology techniques. The approach of the immune system in relation to the combat of this infection follows same particularities. Conclusion: This review demonstrated that the determination of the etiologic agent is essential for the conduct to be taken with the infected individual. Moreover, the immune system is directed related to the viruses elimination, presenting some particularities. In addition, this review highlights that the vaccination is the main responsible for reducing people infected by viruses A and B

Phenomenology of a flavored multiscalar Branco-Grimus-Lavoura-like model with three generations of massive neutrinos

In this paper, we present several possible anomaly free implementations of the Branco-Grimus-Lavoura (BGL) model with two Higgs doublets and one singlet scalar. The model also includes three generations of massive neutrinos that get their mass via a type-I seesaw mechanism. A particular anomaly free realization, which we dub νBGL-1 scenario, is subjected to an extensive phenomenological analysis, from the perspective of flavor physics and collider phenomenology.publishe

Vitamin C and E supplementation prevents mitochondrial damage of ileum myocytes caused by intense and exhaustive exercise training

Rosa EF, Ribeiro RF, Pereira FM, Freymuller E, Aboulafia J, Nouailhetas VL. Vitamin C and E supplementation prevents mitochondrial damage of ileum myocytes caused by intense and exhaustive exercise training. J Appl Physiol 107: 1532-1538, 2009. First published August 20, 2009; doi: 10.1152/japplphysiol.91166.2008.Intense and exhaustive exercise (IEE) is associated with oxidative stress in skeletal muscle, and we recently reported that intestine is sensitive to IEE. in the present study, we investigated the possible relationship between the effects of IEE on morphology and oxidative markers in the ileum and isolated mitochondria. C57BL/6 mice were ascribed either to a control group comprising two subgroups, one sedentary and another exercised for 10 days (E10), or to a corresponding supplemented control group again comprising two subgroups, one sedentary and another exercised for 10 days (E10-V). the IEE program consisted of a single daily treadmill running session at 85% of V(max), until animal exhaustion. Vitamins C (10 mg/kg) and E (10 mg/kg) were concurrently intraperitoneally administered 2 h before the exercise sessions. IEE was shown to cause 1) impairment of ileum internal membrane mitochondria verified by ultramicrography analysis; 2) increase in ileum carbonyl content (117%) and reduction in antioxidant capacity (36%); 3) increase in mitochondria carbonyl content (38%), increase in the percentage of ruptured mitochondria 25.3%), increase in superoxide dismutase activity (186%), and reduction in citrate synthase activity (40.4%) compared with control animals. Observations in the vitamin-supplemented exercised animals (E10-V) were 1) healthy appearance of myocyte mitochondria; 2) decrease in ileum carbonyl content (66%) and increase in antioxidant capacity (53%); 3) decrease in mitochondria carbonyl content (43%), decrease in the percentage of ruptured mitochondria (30%), slight increase in superoxide dismutase activity (7%), and significant increase in citrate synthase activity (121%) compared with E10 animals. Therefore, the present results strongly corroborate the hypothesis that IEE leads to marked disturbances in intestinal mitochondria, mainly in redox status, and affects whole intestinal redox status.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Federal de São Paulo, Escola Paulista Med, Dept Biophys, BR-04023062 São Paulo, BrazilUniversidade Federal de São Paulo, Ctr Electron Microscopy, BR-04023062 São Paulo, BrazilCtr Univ Sao Camilo, São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Biophys, BR-04023062 São Paulo, BrazilUniversidade Federal de São Paulo, Ctr Electron Microscopy, BR-04023062 São Paulo, BrazilWeb of Scienc

Antimicrobial and Antiinsectan Phenolic Metabolites of Dalea searlsiae

Continued interest in the chemistry of Dalea spp. led to investigation of Dalea searlsiae, a plant native to areas of the western United States. Methanol extractions of D. searlsiae roots and subsequent chromatographic fractionation afforded the new prenylated and geranylated flavanones malheurans A–D (1–4) and known flavanones (5 and 6). Known rotenoids (7 and 8) and isoflavones (9 and 10) were isolated from aerial portions. Structure determination of pure compounds was accomplished primarily by extensive 1D- and 2D-NMR spectroscopy. The absolute configurations of compounds 1–5, 7, and 8 were assigned using electronic circular dichroism spectroscopy. Antimicrobial bioassays revealed significant activity concentrated in the plant roots. Compounds 1–6 exhibited MICs of 2–8 μg/mL against Streptococcus mutans, Bacillus cereus, and oxacillin-sensitive and -resistant Staphylococcus aureus. Aerial metabolites 7–10 were inactive against these organisms, but the presence of 7 and 8 prompted investigation of the antiinsectan activity of D. searlsiae metabolites toward the major crop pest Spodoptera frugiperda (fall armyworm). While compounds 1–10 all caused significant reductions in larval growth rates, associated mortality (33–66%) was highest with flavanone 4 and rotenoids 7 and 8. These findings suggest a differential allocation of antimicrobial and antiinsectan plant resources to root and aerial portions of the plant, respectively

Anomalous Nernst Effect in flexible co-based amorphous ribbons

Fe3Co67Cr3Si15B12 ribbons with a high degree of flexibility and excellent corrosion stability were produced by rapid quenching technique. Their structural, magnetic, and thermomagnetic (Anomalous Nernst Effect) properties were studied both in an as-quenched (NR) state and after stress annealing during 1 h at the temperature of 350 °C and a specific load of 230 MPa (AR). X-ray diffraction was used to verify the structural characteristics of our ribbons. Static magnetic properties were explored by inductive technique and vibrating sample magnetometry. The thermomagnetic curves investigated through the Anomalous Nernst Effect are consistent with the obtained magnetization results, presenting a linear response in the thermomagnetic signal, an interesting feature for sensor applications. Additionally, Anomalous Nernst Effect coefficient SANE values of 2.66μV/K and 1.93μV/K were estimated for the as-quenched and annealed ribbons, respectively. The interplay of the low magnetostrictive properties, soft magnetic behavior, linearity of the thermomagnetic response, and flexibility of these ribbons place them as promising systems to probe curved surfaces and propose multifunctional devices, including magnetic field-specialized sensors.M.A.C. thanks CAPES (8887.573100/2020-00) and CNPq. A.F. thanks the FCT (CTTI-31/18- C.F. (2) junior researcher contract). G.V.K was supported in the frame of the Priority-2030 Program of Ural Federal University

On the bioactivity of Echinacea purpurea extracts to modulate the production of inflammatory mediators

Inflammatory diseases are the focus of several clinical studies, due to limitations and serious side effects of available therapies. Plant-based drugs (e.g., salicylic acid, morphine) have become landmarks in the pharmaceutical field. Therefore, we investigated the immunomodulatory effects of flowers, leaves, and roots from Echinacea purpurea. Ethanolic (EE) and dichloromethanolic extracts (DE) were obtained using the Accelerated Solvent Extractor and aqueous extracts (AE) were prepared under stirring. Their chemical fingerprint was evaluated by liquid chromatography–high resolution mass spectrometry (LC-HRMS). The pro- and anti-inflammatory effects, as well as the reduction in intracellular reactive oxygen and nitrogen species (ROS/RNS), of the different extracts were evaluated using non-stimulated and lipopolysaccharide-stimulated macrophages. Interestingly, AE were able to stimulate macrophages to produce pro-inflammatory cytokines (tumor necrosis factor -TNF-α, interleukin -IL-1β, and IL-6), and to generate ROS/RNS. Conversely, under an inflammatory scenario, all extracts reduced the amount of pro-inflammatory mediators. DE, alkylamides-enriched extracts, showed the strongest anti-inflammatory activity. Moreover, E. purpurea extracts demonstrated generally a more robust anti-inflammatory activity than clinically used anti-inflammatory drugs (dexamethasone, diclofenac, salicylic acid, and celecoxib). Therefore, E. purpurea extracts may be used to develop new effective therapeutic formulations for disorders in which the immune system is either overactive or impaired.This research was funded by the Fundação para a Ciência e a Tecnologia (FCT) to the PhD grant of SFV (PD/BD/135246/2017 and COVID/BD/152012/2021) and the projects PATH (PD/00169/2013), FROnTHERA (NORTE-01-0145-FEDER-000023), Cells4_IDs (PTDC/BTM-SAL/28882/2017), and the NORTE 2020 Structured Project, co-funded by Norte2020 (NORTE-01-0145-FEDER-000021). This research was also partially supported by national funds by FCT through the projects UIDB/04423/2020 and UIDP/04423/2020 (Group of Natural Products and Medicinal Chemistry-CIIMAR) and ERDF, through the COMPETE—POFC program in the framework of the program PT2020

Predictors of gaming disorder in children and adolescents : a school-based study

Objective: To determine whether psychiatric and gaming pattern variables are associated with gaming disorder in a school-based sample. Methods: We analyzed data from the Brazilian High-Risk Cohort for Psychiatric Disorders, a community sample aged 10 to 18, using questionnaires on gaming use patterns. We applied the Gaming Addiction Scale to diagnose gaming disorder and the Development and Well-Being Behavior Assessment for other diagnoses. Results: Out of 407 subjects, 83 (20.4%) fulfilled the criteria for gaming disorder. More role-playing game players were diagnosed with gaming disorder that any other genre. Gaming disorder rates increased proportionally to the number of genres played. Playing online, being diagnosed with a mental disorder, and more hours of non-stop gaming were associated with higher rates of gaming disorder. When all variables (including age and gender) were considered in a logistic regression model, the number of genres played, the number of non-stop hours, the proportion of online games, and having a diagnosed mental disorder emerged as significant predictors of gaming disorder. Conclusion: Each variable seems to add further risk of gaming disorder among children and adolescents. Monitoring the length of gaming sessions, the number and type of genres played, time spent gaming online, and behavior changes may help parents or guardians identify unhealthy patterns of gaming behavior

Improving the room-temperature ferromagnetism in ZnO and low-doped ZnO:Ag films using GLAD sputtering

ZnO and doped ZnO films with non-ferromagnetic metal have been widely used as biosensor elements. In these studies, the electrochemical measurements are explored, though the electrical impedance of the system. In this sense, the ferromagnetic properties of the material can be used for multifunctionalization of the sensor element using external magnetic fields during the measurements. Within this context, we investigate the room-temperature ferromagnetism in pure ZnO and Ag-doped ZnO films presenting zigzag-like columnar geometry. Specifically, we focus on the films’ structural and quasi-static magnetic properties and disclose that they evolve with the doping of low-Ag concentrations and the columnar geometry employed during the deposition. The magnetic characterization reveals ferromagnetic behavior at room temperature for all studied samples, including the pure ZnO one. By considering computational simulations, we address the origin of ferromagnetism in ZnO and Ag-doped ZnO and interpret our results in terms of the Zn vacancy dynamics, its substitution by an Ag atom in the site, and the influence of the columnar geometry on the magnetic properties of the films. Our findings bring to light an exciting way to induce/explore the room-temperature ferromagnetism of a non-ferromagnetic metal-doped semiconductor as a promising candidate for biosensor applications.This works was partially supported by the Brazilian agencies CNPq and CAPES. Furthermore, this work was also supported by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UID/FIS/04650/2019 and project PTDC/BTMMAT/28237/2017. A. Ferreira thanks FCT for the contract under the Stimulus of Scientific Employment (CTTI-31/18–CF (2) junior researcher contract). RMT thanks the Center for Computational Engineering & Sciences (CCES) at Unicamp for financial support through the FAPESP/CEPID Grant 2013/08293-7. LDM would also like to thank the support of the High-Performance Computing Center at UFRN (NPAD/UFRN). The work reported in this paper was supported by On-Surf Mobilizar Competencias Tecnologicas em Engenharia de Superficies, Project POCI-01-0247-FEDER-024521