Genetic analysis of porcine circovirus type 2 from pigs affected with PMWS in Chile reveals intergenotypic recombination

Background: Porcine circovirus type 2 (PCV2) is a very small, non-enveloped and icosahedral virus, with circular single stranded DNA genome. This virus is the most ubiquitous and persistent pathogen currently affecting the swine industry worldwide. PCV2 has been implicated as the major causative agent of postweaning multisystemic wasting syndrome (PMWS), a disease which is characterized by severe immunosuppressive effects in the porcine host. Worldwide PCV2 isolates have been classified into four different genotypes, PCV2a, PCV2b, PCV2c and PCVd. The goal of this work was to conduct the first phylogenetic analysis of PCV2 in Chile. Methods: PCV2 partial ORF2 sequences (462 nt) obtained from 29 clinical cases of PMWS in 22 Chilean intensive swine farms, covering over the 90% of the local pork-production, were analyzed. Results: 14% and 52% of sequences belonged to the genotypes PCV2a and PCV2b, respectively. Surprisingly, 34% of sequences were PCV2a/PCV2d recombinant viruses. Conclusions: Our findings suggested that a novel cluster of Chilean sequences emerged resulting from intergenotypic recombination between PCV2a and PCV2d

Mineral composition of bee pollen and its relationship with botanical origin and harvesting period

Producción CientíficaIn the present study, the mineral composition of seventy-one bee pollen samples from four different apiaries was determined by means of inductively coupled plasma-optical emission spectrometry. The results showed that there were no significant differences in relation to the overall mineral content per sample in terms of the apiary of origin or the harvesting period; the most common elements were phosphorus and potassium with concentrations ranging from 2.3 to 5.1 g/kg (dry weight). Moreover, the mineral content of the samples analyzed was similar to or higher than the recommended as well-balanced food for bees. Regarding the nutritional value for humans, bee pollen samples could be considered as a food rich in copper, iron, magnesium, manganese, and phosphorus. Finally, a canonical discriminant analysis was performed, and it was found that the apiary of origin could be distinguished by using the first three canonical functions; furthermore, over 90% of the samples could be correctly assigned to their corresponding apiary. The results were even better as regards the harvesting period, as only the first two canonical functions were sufficient to make a distinction between the different harvesting periods, resulting in a perfect match (100% of success rate).Ministerio de Economía y Competitividad (RTI2018-096268-B-100)Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (RTA 2015-00013-C03-01 and 03)FEDER and FSE (project AGRISOST-CM S2018/BAA-4330

Simulación de un control de corriente Para un Inversor Trifásico Utilizando un Solo Sensor de Corriente

En este trabajo se presenta un control de corriente para un inversor trifásico alimentado en voltaje con cargas balanceadas, dicho control es llevado a cabo, utilizando un solo sensor de corriente, con la finalidad de tener un bajo costo en el control de un inversor trifásico. Así mismo, se describe el funcionamiento de este control, el cual se basa en el seguimiento de una señal de referencia senoidal y la utilización de los patrones de la técnica de modulación por espacio vectorial (SVPWM).Con base a esto, los resultados obtenidos de la simulación son mostrados, con el fin de evaluar la propuest

Nuevo inversor fotovoltaico integrado sin transformador

Los inversores sin transformador son ampliamente utilizados en sistemas fotovoltaicos conectados a la red eléctrica, debido a los beneficios de lograr alta eficiencia y bajo costo.El inversor fotovoltaico sin transformador puede generar una corriente de fuga entre el inversor y la red eléctrica, a través de la capacitancia parásita del módulo fotovoltaico y la tierra física. Esta corriente de fuga provoca una disminución de la eficiencia, reduce el tiempo de vida del módulo fotovoltaico y pone en riesgo al personal que esté en contacto con el sistema. Se han propuesto varias topologías de inversores sin transformador para reducir esta corriente de fuga; este trabajo propone una topología diferente que consiste en la integración de dos etapas, un inversor puente completo y un convertidor CD/CD elevador. Una terminal de salida del inversor está conectada directamente a tierra y el convertidor es controlado por modos deslizantes.Palabra(s) Clave(s): control por modos deslizantes, corriente de fuga, inversor fotovoltaico

Sistema fotovoltaico multifuncional conectado a la red eléctrica controlado por medio de modos deslizantes

Debido al uso de cargas electrónicas no lineales, la calidad de la energía eléctrica se ha ido deteriorando. Con el creciente uso de fuentes renovables de energía interconectadas a la red eléctrica es posible integrar la función de los filtros activos de potencia a los sistemas fotovoltaicos (PV, por sus siglas en inglés) conectados a la red, modificando el control del convertidor. Debido a lo antes mencionado en este trabajo se propone el uso de un sistema PV controlado por medio de modos deslizantes, con una superficie deslizante capaz de inyectar tanto potencia activa como reactiva para eliminar los armónicos de corriente en el punto de acoplamiento común (PAC) y mantener un factor de potencia elevado aún ante la presencia de cargas no lineales, con la ventaja de una fácil implementación.El sistema es diseñado y simulado, con lo cual se confirma la eficacia del controlador por modos deslizantes propuesto. Además se mencionan las ventajas sobre los inversores PV convencionales.Palabra(s) Clave(s): control por modos deslizantes, inversor fotovoltaico, potencia activa, superficie de deslizamiento

Reappraisal of the outcome of healthcare-associated and community-acquired bacteramia: a prospective cohort study

Background: Healthcare-associated (HCA) bloodstream infections (BSI) have been associated with worse outcomes, in terms of higher frequencies of antibiotic-resistant microorganisms and inappropriate therapy than strict community-acquired (CA) BSI. Recent changes in the epidemiology of community (CO)-BSI and treatment protocols may have modified this association. The objective of this study was to analyse the etiology, therapy and outcomes for CA and HCA BSI in our area. Methods: A prospective multicentre cohort including all CO-BSI episodes in adult patients was performed over a 3-month period in 2006–2007. Outcome variables were mortality and inappropriate empirical therapy. Adjusted analyses were performed by logistic regression. Results: 341 episodes of CO-BSI were included in the study. Acquisition was HCA in 56% (192 episodes) of them. Inappropriate empirical therapy was administered in 16.7% (57 episodes). All-cause mortality was 16.4% (56 patients) at day 14 and 20% (71 patients) at day 30. After controlling for age, Charlson index, source, etiology, presentation with severe sepsis or shock and inappropriate empirical treatment, acquisition type was not associated with an increase in 14-day or 30-day mortality. Only an stratified analysis of 14th-day mortality for Gram negatives BSI showed a statically significant difference (7% in CA vs 17% in HCA, p = 0,05). Factors independently related to inadequate empirical treatment in the community were: catheter source, cancer, and previous antimicrobial use; no association with HCA acquisition was found. Conclusion: HCA acquisition in our cohort was not a predictor for either inappropriate empirical treatment or increased mortality. These results might reflect recent changes in therapeutic protocols and epidemiological changes in community pathogens. Further studies should focus on recognising CA BSI due to resistant organisms facilitating an early and adequate treatment in patients with CA resistant BSI

Bienestar mental y optimismo laboral en empleados turísticos de una región de Perú

The objective was to determine the relationship between mental well-being and labor optimism in tourist collaborators in the Junín region. The paradigm was positivist-quantitative, basic type, relational level, non-experimental-transectional design. Observational and inductive-deductive method. The probabilistic-stratified sample consisted of 384 dependents. The results showed that there is a direct and significant correlation between positive mental health and optimism, with a bilateral significance level of less than 1%, as well as a Kendall Tau b correlation strength of 0.445. It is concluded that the greater the mental well-being, the greater the labor optimism.El objetivo fue determinar la relación entre bienestar mental y optimismo laboral en colaboradores turísticos de la región Junín. El paradigma fue positivista-cuantitativo, tipo básico, nivel relacional, diseño no experimental. Método observacional e inductivo-deductivo. La muestra probabilística-estratificada fue de 384 dependientes. Los resultados mostraron que existe correlación directa y significativa entre salud mental positiva y optimismo, con un nivel de significancia bilateral inferior al 1 %, así como una fuerza de correlación Tau b de Kendall de 0.445. Se concluye que, a mayor bienestar mental, mayor optimismo laboral

Randomized Clinical Trials of obesity treatments in Mexican population. Systematic Review and Meta-Analysis

Background: Mexicans and Mexican Americans share similar culture, genetic background, and predisposition for obesity and diabetes. Randomized clinical trials (RCT) assessing obesity treatments (ObT) are reliable to assess efficacy. To date, there is no systematic review to investigate ObT tested by RCT in Mexican adults. Methods: We conducted systematic searches in Pubmed, Scopus, and Web of Science to retrieve ObT RCT from 1990 to 2019. The ObT included alternative medicine, pharmacological, nutritional, behavioral, and surgical interventions. The analyzed RCT were at least three months of duration, and reported: BMI, weight, waist circumference, triglycerides, glucose and blood pressure. Results: We found 634 entries; after removal of duplicates and exclusions based on eligibility criteria, we analyzed 43 and 2 multinational-collaborative studies. Most of the national studies had small sample sizes, and did not have replications from other studies. The nutrition/behavioral interventions were difficult to blind, and most studies had medium to high risk of bias. Random effects meta-analysis of nutritional/behavioral interventions and medications showed effects on BMI, waist circumference, and blood pressure. Simple measures like plain water instead of sweet beverages decreased triglycerides and systolic blood pressure. Participants with obesity and hypertension had beneficial effects with antioxidants, and the treatment with insulin increased weight in those with T2D. Conclusions: The RCT’s in Mexico reported effects on metabolic components despite small sample sizes and lack of replication. In the future we should analyze ObT in population living on the U.S.-Mexico border; therefore, bi-national collaboration is desirable to disentangle cultural effects on ObT response

Ki-67 expression is superior to mitotic count and novel proliferation markers PHH3, MCM4 and mitosin as a prognostic factor in thick cutaneous melanoma

<p>Abstract</p> <p>Background</p> <p>Tumor cell proliferation is a predictor of survival in cutaneous melanoma. The aim of the present study was to evaluate the prognostic impact of mitotic count, Ki-67 expression and novel proliferation markers phosphohistone H3 (PHH3), minichromosome maintenance protein 4 (MCM4) and mitosin, and to compare the results with histopathological variables.</p> <p>Methods</p> <p>202 consecutive cases of nodular cutaneous melanoma were initially included. Mitotic count (mitosis per mm²) was assessed on H&E sections, and Ki-67 expression was estimated by immunohistochemistry on standard sections. PHH3, MCM4 and mitosin were examined by staining of tissue microarrays (TMA) sections.</p> <p>Results</p> <p>Increased mitotic count and elevated Ki-67 expression were strongly associated with increased tumor thickness, presence of ulceration and tumor necrosis. Furthermore, high mitotic count and elevated Ki-67 expression were also associated with Clark's level of invasion and presence of vascular invasion. High expression of PHH3 and MCM4 was correlated with high mitotic count, elevated Ki-67 expression and tumor ulceration, and increased PHH3 frequencies were associated with tumor thickness and presence of tumor necrosis. Univariate analyses showed a worse outcome in cases with elevated Ki-67 expression and high mitotic count, whereas PHH3, MCM4 and mitosin were not significant. Tumor cell proliferation by Ki-67 had significant prognostic impact by multivariate analysis.</p> <p>Conclusions</p> <p>Ki-67 was a stronger and more robust prognostic indicator than mitotic count in this series of nodular melanoma. PHH3, MCM4 and mitosin did not predict patient survival.</p