Effect of the Longitudinal Tensile Creep on the Stiffness of Radiata Pine (Pinus radiata D. Don).

The influence of load on the cellulose microfibrils of single cells or thin wood foils is known. It can decrease the cellulose microfibril angles and, in turn, increase the stiffness. However, this modification of a piece of wood, which is made up of multiple cells, is unknown. The aim of this research was to study the effect of tensile creep on the longitudinal stiffness of radiata pine wood. The modulus of elasticity of each specimen was determined before and after being subjected to tensile creep. The samples were loaded at 1170 N and 1530 N for 20 min at 70 °C. The load was determined as a function of a percentage of the force at the proportional limit. The moduli of elasticity before and post-tensile creep showed no effect on the stiffness of wood at the macroscopic level, but neither were there damage to the cell structure. It can be assumed that there are changes at the microscopic level, but they are not enough to be reflected at the macro scale. It is also challenging to achieve the modifications that occur at the level of a single cell or in thin wood foils; however, the implications of this would be favorable for the development of stronger wood-based products.

Evaluation of the PLA-nZH-Cu Nanocomposite Film on the Micro-Biological, Organoleptic and Physicochemical Qualities of Packed Chicken Meat.

This research evaluated the contribution of nanocomposite films based on different concentrations of nZH-Cu (1%, 2%, and 3%) to the microbiological, organoleptic, and physicochemical characteristics of packed chicken breast meat. Analysis of some meat quality traits, such as microbiological, chemical, and physical, were conducted on a laboratory scale. For this, small squares of chicken breast meat, weighing approximately 10 g, were aseptically wrapped with rectangular pieces of 5 × 10 cm PLA-nZH-Cu nanocomposite films, which were stored at 4 °C for 20 days. The microbiological results indicated efficient antibacterial activity (at any nZH-Cu concentration in the nanocomposite films) on the total viable count of groups of psychrophiles, aerobic mesophiles, Enterobacteriaceae, and Salmonella spp. until day 10 of storage (p < 0.05). No significant changes were observed in the organoleptic (color) and physicochemical qualities (texture, weight, pH, and acidity) until day 10 of storage at 4 °C (p < 0.05). The analysis of the experimental tests carried out determined that the PLA-nZH-Cu nanocomposite films played an effective role in the bacterial safety of the packaged chicken. It was concluded that the nZH-Cu nanocomposite films, at all concentrations tested, extended the shelf life of the chicken breast meat for up to 10 days in a refrigerator at 4 °C.

Africanized honey bees in Colombia exhibit high prevalence but low level of infestation of Varroa mites and low prevalence of pathogenic viruses.

The global spread of the ectoparasitic mite Varroa destructor has promoted the spread and virulence of highly infectious honey bee viruses. This phenomenon is considered the leading cause for the increased number of colony losses experienced by the mite-susceptible European honey bee populations in the Northern hemisphere. Most of the honey bee populations in Central and South America are Africanized honey bees (AHBs), which are considered more resistant to Varroa compared to European honey bees. However, the relationship between Varroa levels and the spread of honey bee viruses in AHBs remains unknown. In this study, we determined Varroa prevalence and infestation levels as well as the prevalence of seven major honey bee viruses in AHBs from three regions of Colombia. We found that although Varroa exhibited high prevalence (92%), its infestation levels were low (4.5%) considering that these populations never received acaricide treatments. We also detected four viruses in the three regions analyzed, but all colonies were asymptomatic, and virus prevalence was considerably lower than those found in other countries with higher rates of mite-associated colony loss (DWV 19.88%, BQCV 17.39%, SBV 23.4%, ABPV 10.56%). Our findings indicate that AHBs possess a natural resistance to Varroa that does not prevent the spread of this parasite among their population, but restrains mite population growth and suppresses the prevalence and pathogenicity of mite-associated viruses.

Early identification of COVID-19 cytokine storm and treatment with anakinra or tocilizumab.

OBJECTIVE: To examine outcomes among patients who were treated with the targeted anti-cytokine agents, anakinra or tocilizumab, for COVID-19 -related cytokine storm (COVID19-CS). METHODS: We conducted a retrospective cohort study of all SARS-coV2-RNA-positive patients treated with tocilizumab or anakinra in Kaiser Permanente Southern California. Local experts developed and implemented criteria to define COVID19-CS. All variables were extracted from electronic health records. RESULTS: At tocilizumab initiation (n = 52), 50 (96.2%) were intubated, and only seven (13.5%) received concomitant corticosteroids. At anakinra initiation (n = 41), 23 (56.1%) were intubated, and all received concomitant corticosteroids. Fewer anakinra-treated patients died (n = 9, 22%) and more were extubated/never intubated (n = 26, 63.4%) compared to tocilizumab-treated patients (n = 24, 46.2% dead, n = 22, 42.3% extubated/never intubated). Patients who died had more severe sepsis and respiratory failure and met COVID-CS laboratory criteria longer (median = 3 days) compared to those extubated/never intubated (median = 1 day). After accounting for differences in disease severity at treatment initiation, this apparent superiority of anakinra over tocilizumab was no longer statistically significant (propensity score-adjusted hazards ratio 0.46, 95% confidence interval 0.18-1.20). CONCLUSIONS: Prompt identification and treatment of COVID19-CS before intubation may be more important than the specific type of anti-inflammatory treatment. Randomized controlled trials of targeted anti-cytokine treatments and corticosteroids should report the duration of cytokine storm in addition to clinical severity at randomization.

Obtaining Nanoparticles of Chilean Natural Zeolite and its Ion Exchange with Copper Salt (Cu2+) for Antibacterial Applications.

This article describes the production of nanoparticles of Chilean natural zeolite, using three size reduction methods: Ball mill, microgrinding, and microfluidization. Morphological characterization of samples indicated an average diameter of 37.2 ± 15.8 nm of the zeolite particles. The size reduction and chemical treatments did not affect the morphology or integrity of the zeolite. An increase of the zeolite samples' Si/Al ratio was observed after the acid treatment and was confirmed by SEM-EDX analysis. Moreover, the effectiveness of the copper salt ion exchange (Cu2+) to the zeolite nanoparticles was analyzed by SEM-EDX. XRD analysis indicated that clinoptilolite and mordenite are the main phases of Chilean natural zeolite, and the crystalline structure was not affected by the modification processes. The FTIR characterization showed the presence of chemical bonds of copper with the zeolite nanoparticle framework. The ion-exchanged zeolite nanoparticles were evaluated for antibacterial behavior by the disc diffusion method. Additionally, the minimum inhibitory concentration and minimum bactericidal concentration were obtained. Microbiological assays with copper-exchanged nanozeolites showed an antimicrobial activity with a bactericidal effect against Escherichia coli and Staphylococcus aureus, which are the primary pathogens of food and are also resistant to multiple drugs. In this study, a new application for natural nanozeolites is demonstrated, as the incorporated copper ions (Cu2+) in nanozeolites registered a productive antibacterial activity.

Bee pathogens found in Bombus atratus from Colombia: A case study.

Bombus atratus bumblebees from Colombia that were caught in the wild and from breeding programs were screened for a broad set of bee pathogens. We discovered for the first time Lake Sinai Virus and confirmed the infection by other common viruses. The prevalence of Apicystis bombi, Crithidia bombi and Nosema ceranae was remarkably high. According to other studies the former two could have been co-introduced in South America with exotic bumble bees as Bombus terrestris or Bombus ruderatus. Given the fact that none of these species occur in Colombia, our data puts a new light on the spread of these pathogens over the South American continent.

CARACTERIZACIÓN ANTIMICROBIANA Y FISICOQUÍMICA DE PROPÓLEOS DE Apis mellifera L. (HYMENOPTERA: APIDAE) DE LA REGIÓN ANDINA COLOMBIANA / Antimicrobial and Physico-Chemical Characterization of Propolis of Apis mellifera L. (Hymenoptera: Apidae) from the Colombian Andes

El propóleo es un material resinoso producido por las abejas a partir de diversos materiales vegetales. El objetivo de este trabajo fue caracterizar muestras de propóleos de Apis mellifera provenientes de la región Andina colombiana respecto a su perfil antimicrobiano y fisicoquímico. Fueron empleados extractos etanólicos de propóleos por la técnica de disco-difusión, frente a las especies Escherichia coli, Staphylococcus aureus y Candida albicans. Para la caracterización fisicoquímica se evaluaron el porcentaje de extracto seco, contenido de cera, índice de oxidación y determinación cuantitativa de compuestos fenólicos y flavonoides. Todas las muestras presentaron actividad antibacteriana, con halos de inhibición comprendidos entre 8 y 12 mm para E. coli y entre 8,3 y 23,5 mm para S. aureus. No se observó ninguna actividad contra C. albicans. Los parámetros fisicoquímicos citados anteriormente presentaron una variación de 2,72 a 9,17%, 0 a 2%, 3 a 51s, 0,1 a 0,5 (p/p) y 0,02 a 0,95 (p/p), respectivamente. El perfil antimicrobiano observado, relacionado al fisicoquímico, sugiere la necesidad de nuevos estudios para la determinación del origen botánico y geográfico de las muestras estudiadas.

Propolis is a resinous material produced by bees from various plant sources. The objective of this study was to characterize propolis samples of Apis mellifera from the Colombian Andean region, regarding the antimicrobial and physicochemical profiles. We used the technique of disk diffusion with ethanol extracts of propolis against Escherichia coli, Staphylococcus aureus and Candida albicans. The physicochemical characterization included percentage of solids content, wax, oxidation index and quantitative determination of phenolic and flavonoids compounds. All samples showed antibacterial activity, with inhibition zones between 8,0 and 12,0 mm for E. coli and between 8,3 and 23,5 mm for S. aureus. We did not observe any activity against C. albicans. The physical and chemical parameters cited above showed a variation from 2.72 to 9.17%, 0 to 2%, 3 to 51 s, 0.1 to 0.5 (w/w) and 0.02 to 0.95 (p/p), respectively. The antimicrobial profile observed, related to the physicochemical profile, suggests the need for further studies to determine the geographical and botanical origin of the samples studied.

Síndrome de disfunción congnitiva del perro como modelo de investigación de las enfermedades neurodegenerativas del humano / Cognitive dysfunction syndrome in dog senior: a suitable model for human neurodegenerative diseases

En humanos y caninos, el proceso de envejecimiento aumenta el riesgo de padecer enfermedades neurodegenerativas tales como la enfermedad de Alzheimer y el síndrome de disfunción cognitiva de perros senior. Estos síndromes demenciales provocan alteraciones patológicas en diferentes áreas cerebrales, generando un evidente déficit cognitivo caracterizado por cambios comportamentales como alteración en los procesos de memoria y aprendizaje. Los efectos deletéreos sobre la calidad de vida en pacientes humanos afectados por la enfermedad de Alzheimer, promueven la necesidad de encontrar patologías similares que afecten a otras especies, haciendo de estas, modelos experimentales útiles para la investigación de los padecimientos humanos. Recientemente ha sido sugerida una estrecha similitud entre varias de las características clínicas, anatómicas y fisiopatológicas propias de la enfermedad de Alzheimer y el síndrome de disfunción cognitiva de perros senior, en las que se incluye la formación y acumulación de placas amiloideas, apoptosis de neuronas colinérgicas con la consiguiente disminución del neurotransmisor Acetil-colina, déficit cognitivo de tipo progresivo y alteraciones en el ciclo sueño-vigilia, entre otras. Así, el avance en el conocimiento de los procesos implicados en la fisiopatología del síndrome de disfunción cognitiva de perros senior, y tras reconocer sus similitudes con los ocurridos durante la enfermedad de Alzheimer, ha facilitado los estudios que tienen como objetivo la comprensión de algunos aspectos que aún no han sido muy bien detallados en las enfermedades neurodegenerativas humanas. Además, al considerar la alta probabilidad de padecer el síndrome de disfunción cognitiva de perros senior, que se identifica en algunas poblaciones caninas, da cabida a la posibilidad de proponer al perro, como un modelo óptimo de experimentación para la investigación de los procesos neurodegenerativos asociados al envejecimiento de los humanos.

[The serological prevalence of Salmonella enteritidis amongst Tunja's canine population (a large Colombian city)]. / Prevalencia Serológica de Salmonellaenteritidis en la Población Canina del Municipio de Tunja, Colombia.

OBJECTIVE: Determining the serological prevalence of Salmonella enteritidis in the city of Tunja's canine population (in Boyacá) from July to October 2006 and establishing the relationship between predisposed factors and seroreactivity within this canine population. MATERIALS AND METHODS: 72 canine blood samples were gathered from all of the city's five areas from an estimated 9623 canine population (2002 census), assuming a 3% pre-established critical prevalence and 95% confidence level. A survey was made of each animal to determine the presence of predisposed factors and they were all given a complete clinical examination. The sera so obtained were used for titering antibody levels by means of the microagglutination plate test for Salmonella enteritidis (MAG). RESULTS: Salmonella enteritidis serological prevalence was 41.7%. Area prevalence within the city was 10% for the north, 10% for the west, 16.7% for the east, 36.7% the south and 26.6% for the city-center. A direct correlation was established with the presentation of previous enteric problems (p<0.05) (OR 3.5) and, to a lesser extent, with access to organic waste (p<0.05) (OR 0.4). Other factors presented positive risk levels, such as coexistence with other animals and health (OR 1.4 and OR 2) CONCLUSIONS: Salmonella enteritidis had a high serological prevalence in the city of Tunja, most incidents occurring in the southern area. The presentation of previous enteric problems was the main predisposed factor, this being a high risk factor in this entity's dissemination.

Prevalencia serológica de Salmonellaenteritidis en la población canina del Municipio de Tunja, Colombia / The serological prevalence of Salmonella enteritidis amongst Tunja's canine population (a large Colombian city)

Objetivo Determinar la prevalencia serológica de Salmonella enteritidis en la población canina de Tunja (Boyacá), durante julio y octubre del 2006 y establecer la relación entre los factores predisponentes y la serorreactividad en la población canina. Materiales y Métodos Sobre la población canina estimada en 9 623 animales (censo de 2002), y asumiendo una prevalencia critica preestablecida de 3 por ciento y un nivel de confianza del 95 por ciento, se recolectaron 72 muestras sanguíneas caninas distribuidas en cinco zonas de la ciudad, se aplicó una encuesta para cada animal para determinar la presencia de factores predisponentes y un examen clínico completo. Con los sueros obtenidos, se tituló el nivel de anticuerpos mediante la prueba de microaglutinación en placa para Salmonella enteritidis (MAG). Resultados La prevalencia serológica a Salmonella enteritidis fue del 41,7 por ciento, las prevalencias zonales fueron: 10 por ciento Norte, 10 por ciento occidente, 16,7 por ciento Oriente, 36,7 por ciento sur y 26,6 por ciento centro. Se determinó una correlación directa con la presentación de problemas entéricos anteriores (p<0,05) (OR 3,5) y en menor grado con el acceso a desechos orgánicos (p<0,05) (OR 0,4); otros factores como la convivencia con otros animales y la salud mostraron niveles de riesgo positivo (OR 1,4 Y OR 2). Conclusiones Existe una alta prevalencia serológica a Salmonella enteritidis en la ciudad de Tunja, con mayor incidencia en la zona sur, siendo el principal factor predisponente la presentación de problemas entéricos anteriores, el cual es un factor de alto riesgo en la diseminación de esta entidad.

Objective Determining the serological prevalence of Salmonella enteritidis in the city of Tunja's canine population (in Boyacá) from July to October 2006 and establishing the relationship between predisposed factors and seroreactivity within this canine population. Materials and Methods 72 canine blood samples were gathered from all of the city's five areas from an estimated 9 623 canine population (2002 census), assuming a 3 percent pre-established critical prevalence and 95 percent confidence level. A survey was made of each animal to determine the presence of predisposed factors and they were all given a complete clinical examination. The sera so obtained were used for titering antibody levels by means of the microagglutination plate test for Salmonella enteritidis (MAG). Results Salmonella enteritidis serological prevalence was 41,7 percent. Area prevalence within the city was 10 percent for the north, 10 percent for the west, 16,7 percent for the east, 36,7 percent the south and 26,6 percent for the city-center. A direct correlation was established with the presentation of previous enteric problems (p<0.05) (OR 3.5) and, to a lesser extent, with access to organic waste (p<0.05) (OR 0.4). Other factors presented positive risk levels, such as coexistence with other animals and health (OR 1.4 and OR 2) Conclusions Salmonella enteritidis had a high serological prevalence in the city of Tunja, most incidents occurring in the southern area. The presentation of previous enteric problems was the main predisposed factor, this being a high risk factor in this entity's dissemination.

Efecto antimicrobiano In vitro de propóleos argentinos, colombianos y cubano sobre Streptococcus mutans ATCC 25175 / Antimicrobial effect

Se evaluó la actividad antimicrobiana de cuatro extractos de propóleos argentinos, cinco colombianos y uno cubano frente a Streptococcus mutans ATCC 25175. La actividad bactericida y bacteriostática fue medida por concentración mínima inhibitoria en un rango entre 0.02 y 15 mg/ml. La totalidad de las muestras analizadas presentaron actividad contra Streptococcus mutans a concentraciones de 15 a 3.75 mg/ml. Los propóleos que presentaron mayor efecto bactericida fueron el 2 y el 3 (muestras colombianas) luego de 48 horas de incubación. El mejor efecto bacteriostático lo presentó la muestra 2 (propóleo colombiano) a un periodo de incubación de 24 horas. El 70/100 de las muestras de propóleo incrementaron su actividad luego de un tiempo de incubación de 48 horas, en relación con el efecto detectado a las 24 horas. A mayor exposición de las bacterias al propóleo, las muestras colombianas mostraron un efecto superior, las argentinas un efecto moderado y las demás muestras (30/100), permanecieron estables.

Perfil sociodemográfico de un grupo de trabajadoras sexuales de Puerto Rico / Sociodemographic profile of a group of sex workers in Puerto Rico

This research explored the sociodemographic characteristics, the health perceptions and the distinctive aspects of the sexual work of a group of women sexual workers (n = 311). The study interest was generating data relative to the use of injectable drugs, the prevalence of sexually transmitted diseases (STD), the prevalence of HIV and the risk behaviors of this population group. A remarkable characteristic of the group of women studied was their history of pregnancies at and early age. A high proportion of illness apparently related to the presence of sexually transmitted diseases and limited health care was observed

Mujer y salud en cifras. Puerto Rico, 1994 / Women and health in numbers. Puerto Rico, 1994

The purpose of this study was to explore the health situation of women in Puerto Rico through the analysis of the causes of deaths in medical certification contained in death certificates. The data source used was the computer tape containing the data on deaths occurred in Puerto Rico during 1994. This tape was produced by the Puerto Rico Department of Health. The analysis of the main causes of deaths in women showed a trend associated with chronic and degenerative diseases. This trend is compatible with the one found in women over 65 years old. In women under 65 years of age, this trend was also observed, although other causes were also relevant, like deaths by external causes and AIDS. For the age groups of under 15, 15 to 44, 45 to 64 and 65 and over, the principal causes of deaths were: conditions related to the perinatal period, AIDS, cancer and heart and heart related diseases respectively. The degree of vulnerability to death from certain causes of mortality which changes in importance from one age range to another in the female population of Puerto Rico is shown by the results of this research project

Leprosy in Puerto Rico: a decade later

A study to evaluate the changes in the incidence and prevalence of leprosy in Puerto Rico was done to include the years 1981-1989. During this period, 75 new cases were diagnosed with anaverage of 8.3 cases per year. The yearly incidence was 1.9 cases per million which is significantly lower to the 4.6 per million in the previous study. At the present moment 182 cases are been followed at the Tropical Diseases Clinic of the University of Puerto Rico School of Medicine with a prevalence of 5.4 per 100,000 inhabitants. It is important to notice that 16 percent of the patients at the clinic were foreigners, a significant increase from a previous study. The decrease in the incidence of leprosy may be due to advances in the treatment of the disease and the new approach to integrate the patient into the community