ABSTRACT Plants traditionally used for medicinal use could be an alternative against SARS-CoV-2. In this study, the binding energy of 10 bioactive compounds of plants used in Mexico against COVID-19 was evaluated by molecular docking with two online servers: COVID-19 Docking Server and DockThor. Remdesivir was used as a control. The results showed that Cypellocarpin B, Cypellocarpin C, Luteolin 7-glucoside, and Syringetin glucopyranoside showed the highest binding energy towards Mpro and RdRp proteins with respect to Remdesivir. The comparison of molecular docking servers showed differences in the docking motors and proteins available on each server. The bioactive compounds evaluated can act as potential inhibitors against Mpro and RdRp proteins of COVID-19, according to in silico molecular docking.

RESUMEN Las plantas utilizadas en la medicina tradicional podrían ser una alternativa frente al SARS-CoV-2. En este estudio se evaluó la energía de unión de los bioactivos de 10 plantas de uso en México contra la COVID-19 mediante acoplamiento molecular con dos servidores que están disponibles en línea: COVID-19 Docking Server y DockThor. Remdesivir se usó como control. Los resultados mostraron que Cypellocarpin B, Cypellocarpin C, Luteolin 7-glucoside y Syringetin glucopyranoside mostraron la mayor afinidad hacia las proteínas Mpro y RdRp con respecto a Remdesivir. La comparación de los servidores de acoplamiento molecular mostró diferencias en los motores de acoplamiento y las proteínas disponibles en cada servidor. Los compuestos bioactivos evaluados son capaces de actuar como inhibidores potenciales frente a las proteínas Mpro y RdRp de COVID-19 según el acoplamiento molecular in silico.

Abstract Oxides (Al2O3, SiO2, TiO2, ZrO2, Y2O3, CeO2, MgO) are among the most used reinforcements for Aluminum Matrix Composites (AMC); while the combination of Al with Si, Cu and/or Mg excels among the alloying systems used as matrices. Some works in literature study the effects of the reinforcements and the alloying elements on the composites manufacturing, microstructure and mechanical properties. Nevertheless, it is necessary a recompilation of the interactions oxide reinforcement-alloyed matrix, including the reciprocal effects between them. Our search revealed that not only reactions occur at the interfacial regions, but also other phenomena depending on the reinforcement characteristics and the matrix composition, which affect mechanical properties. These phenomena include modifications in the matrix microstructure and its precipitation process, diffusion of elements through the interfaces, change in the reinforcement wettability by the liquid metal, loss of alloying elements, and deterioration of the reinforcement. This work presents the occurrence of these phenomena for Al matrices with different contents of Si, Cu and Mg reinforced with the most used oxides. Its novelty lies in exploring these combinations of conditions, which could serve as a benchmark study and help for a better understanding and selection of the matrix-reinforcement system.

Resumen En esta investigación se planteó como objetivo caracterizar color, textura y calidad sanitaria de pan adicionado con maíz criollo y cúrcuma. Se realizaron 14 diferentes panes empleando seis tipos de maíces (M1, M2, M3, M4, M5 y M6). Los principales hallazgos fueron a) El color de los maíces, harinas nixtamalizada y masas tuvieron diferencia significativa (p < 0.05) al comparar valores medios de parámetros de Luminosidad, a* y b*. Los maíces azules y rojizo M2 (37.01), M3 (44.06) y M6 (41.07) y, amarillos y amarillo-naranja M1 (21.26), M4 (15.92) y M5 (26.01) presentaron los valores inferiores en L* y superiores en b*, respectivamente. La menor diferencia en color ∆E encontrada en el proceso de transformación de maíz a harina y masa, fue para maíces amarillos. b) En el pan de maíz se encontraron diferencias significativas en variable a* al compararse el mismo tipo de pan durante tres días consecutivos, en los panes BM1, BM5 y BM6, con una disminución de 7.5, 2.6 y 16.9%, con respecto al primer día. c) La calidad sanitaria del pan de trigo mejora con la adición de maíz nixtamalizado y cúrcuma. En los panes adicionados de maíz los que presentaron menor cantidad de colonias de hongos fueron los maíces azules y rojo (M2, M3 y M6). d) La dureza del pan de maíz criollo y cúrcuma no presentó diferencias durante tres días consecutivos beneficiando su conservación. El pan de maíz amarillo y cúrcuma BM1-C mostró incrementos en la dureza en los días 2 y 3.

Abstract The objective of this research was to characterize the color, texture and sanitary quality of bread added with creole corn and turmeric. Fourteen different breads were made using six types of corn (M1, M2, M3, M4, M5 and M6). The main findings were a) The color of the corn, nixtamalized flours and doughs had a significant difference (p < 0.05) when comparing mean values of Luminosity, a* and b* parameters. Blue and reddish corn M2 (37.01), M3 (44.06) and M6 (41.07) and, yellow and yellow orange M1 (21.26), M4 (15.92) and M5 (26.01) presented the lowest values in L* and highest in b*, respectively. The smallest difference in color ∆E found in the transformation process from corn to flour and dough, was for yellow corn. b) In corn bread, significant differences in variable a* were found when comparing the same type of bread for three consecutive days, in breads BM1, BM5 and BM6, with a decrease of 7.5, 2.6 and 16.9%, with respect to the first day. c) The sanitary quality of wheat bread improves with the addition of nixtamalized corn and turmeric. The blue and red corn (M2, M3 and M6) showed the lowest number of fungal colonies in the breads with corn additives. d) The hardness of the bread made with creole corn and turmeric did not show differences during three consecutive days, benefiting its conservation. The yellow corn and turmeric bread BM1-C showed increases in the hardness on days 2 and 3, and the yellow corn and turmeric bread BM1-C showed increases in the hardness on days 2 and 3.

Introduction: The COVID-19 pandemic generated a restructuring of surgical care worldwide due to the disease's high transmissibility and the inherent limitation of available human and material resources. Aim: The study's aim was to describe the impact of the COVID-19 pandemic on the head and neck surgery team at Complejo Asistencial Barros Luco Trudeau (CABL) in clinical-surgical execution and organization of sanitary sequencing measures implemented over time during the first 150 days after the pandemic started in Chile. Materials and Method: We performed a retrospective review of patients undergoing surgery or outpatient evaluation during the COVID-19 period from 03-03-2020 to 07-31-2020, compared to the same time interval in 2019. Clinical characteristics and sanitary measures used during this period were synthesized. Results: We detected a 64% decrease in outpatient care and a 58% decrease in surgical load from 2019. During the COVID-19 period of 2020, a total of 61 patients underwent surgical intervention. The main indication for surgery was cancer, in 75.4% of patients (46). COVID-19 was not reported in any patients in the 14 days following hospitalization. We discussed the perioperative considerations used and the national/institutional sanitary restrictions. Conclusions: The global health crisis to COVID-19 generated a reduction in outpatient care and surgeries performed by the CABL head and neck team. Despite health restrictions, we organized care stratified to preserve critical head and neck non-deferrable cases.

Resumen Introducción: La pandemia COVID-19 generó una reestructuración en la atención quirúrgica mundialmente debido a su alta transmisibilidad y la inherente limitación de los recursos humanos y materiales disponibles. Objetivo: Describir el impacto de la pandemia COVID-19 en el Equipo de Cirugía Cabeza y Cuello del Complejo Asistencial Barros Luco Trudeau (CABL) en su ejecución clínico-quirúrgica y la secuenciación organizada de las medidas sanitarias aplicadas a lo largo del tiempo durante los primeros 150 días de iniciada la pandemia en Chile. Materiales y Método: Realizamos una revisión retrospectiva de los pacientes sometidos a cirugía y/o evaluados ambulatoriamente durante el período COVID-19 comprendido entre el 3 de marzo y el 31 de julio de 2020, comparado con el mismo intervalo de tiempo de 2019. Características clínicas y medidas sanitarias empleadas durante este período fueron sintetizadas. Resultados: Detectamos un descenso del 64% en atención ambulatoria y un descenso del 58% en la carga quirúrgica, comparado con el año 2019. Durante el período COVID-19 de 2020, un total de 61 pacientes fueron sometidos a intervención quirúrgica. La principal indicación de cirugía fue cáncer en un 75,4% (46). No se reportaron pacientes contagiados por COVID-19 en los 14 días siguientes a la hospitalización. Se discuten las consideraciones perioperatorias empleadas y restricciones nacionales/institucionales sanitarias. Conclusión: La crisis sanitaria mundial secundaria al COVID-19 generó una reducción en las atenciones ambulatorias y cirugías realizadas por Equipo de Cabeza y Cuello CABL. A pesar de las restricciones sanitarias, organizamos estratificadamente la atención para preservar la resolución de casos críticos no diferibles en cabeza y cuello.

Abstract Structural and thermoelectric properties of rare-earth zirconates A2Zr2O7, with A = Pr, Nd, Sm, Gd, and Er, were studied. Samples were prepared by solid-state reaction at ambient pressure with temperatures between 1000 and 1400 ◦C. The resulting compounds were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM/EDS). The XRD analyses showed the formation of polycrystalline Pr2Zr2O7, Nd2Zr2O7, Sm2Zr2O7, Gd2Zr2O7, and Er2Zr2O7 phases, with a cubic cell (space group Fm3m) and traces of the raw used materials. The micrographs obtained by SEM show the formation of heterogeneous grains with a size that ranges from 0.7 to 4.7 µm. All A2Zr2O7 samples present porous surfaces. Thermal conductivities were measured at different temperatures, from 300 to 900 K. In most of the samples, the thermal conductivity monotonically decreases with temperature, from 0.40 - 1.17 W/mK at 300 K to 0.27 - 0.77 W/mK at 773.15 K. At a fixed temperature, the thermal conductivity decreases almost monotonically with the ionic radius (IR) of the rare-earth elements (where IR (Er3+) = 0.890 Å < IR (Gd3+) = 0.938 Å < IR (Sm3+) = 0.958 Å < IR (Nd3+) = 0.983 Å < IR (Pr3+) = 0.99 Å).

Abstract The cosmetic industry has turned its attention to using vegetable products; the number of different vegetable oils used in the cosmetic industry has risen in the last years. Therefore, there are opportunities for development and innovation for the cosmetic sector keeping in mind the growing concern for personal well-being. Being necessary to develop new, and more accurate measurement methods not only to assure the product quality, also to understand the effect of the molecular interactions in order to develop new products. In this work, the so-called photopyroelectric techniques are used for studying the thermal effusivity and diffusivity of wheat germ, mamey seed, walnut, coconut, and linseed oils. The thermal conductivity was calculated using a mathematical relationship, and density was measured. Therefore, full thermal characterization is achieved. The obtained values for the studied oils are closed to other vegetable oils already reported. This similarity is partially a consequence of the similar chemical structure presented in this type of materials.

Emerging bacterial resistance to antibiotics increases the need for effective alternatives to control intestinal inflammation and thus gut disorders in piglets. This study evaluated the effects of including Saccharomyces cerevisiae (strain 1026) and Saccharomyces boulardii (CNCM I-1079) as antibiotic alternatives in the starter diets of pigs on the concentrations of ileal inflammatory markers (nuclear factor-KB (NF-kB)), interleukin-6 (IL-6), tumour necrosis factor alpha (TNF-a), and interleukin-12 subunit p40 (IL-12p40), and villus height. Forty piglets were assigned to four experimental diets, namely basal diet (C-), basal diet with antibiotics (C+), basal diet with S. cerevisiae (Sc), and basal diet with S. boulardii (Sb). At 7 and 14 days post weaning, five piglets per diet group were euthanized to quantify the inflammatory markers and to measure villus height. The C- group exhibited the highest concentration of inflammatory markers and the most atrophied villi. The Sc group had intermediate values for both variables. The C+ group had the lowest values for inflammatory markers and the highest villus height was similar to that of the Sb group, which showed low concentrations of inflammatory markers, although not so low as those of the C+ group. Both yeasts could be used as antibiotic alternatives to reduce the use of antibiotics in pig starter diets. However, S. boulardii CNCM I-1079 supplementation controls inflammation and preserves intestinal mucosa more effectively than S. cerevisiae strain 1026.

Abstract In this study the thermal conductivity of a commercial ceramic is determined considering that this property is an essential factor on the building materials. This is the primary indicator of the material suitableness for energy transfer, considering that this kind of construction supplies has many applications as thermal insulations. In this sense, we consider that a commercial tile is usually composed of three layers: substrate, a so-called engine layer, and an enamel layer. Likewise, the thermal properties of the different layers were obtained individually by using two photothermal techniques on the ceramic material; the ceramic tile density was obtained using the Archimedes method. The calculated values show a wide range of thermal conductivity values for the different layers, ranging from1.3 to 4 W m - 1K - 1.

ABSTRACT Background: Recent studies report that patients with chronic pain, they undergo changes in the processing of information that reaches them from the periphery with the mere fact of changing the order in which the stimuli are exercised, for example, when their hands are crossed. In patients with chronic pain, the presence of alterations in their somatotropic frames of reference has been demonstrated, and this is why the strategy of crossing the extremities through the midline could generate changes in the perception of pain. Objective: To evaluate if an analgesic physiotherapy program with hand crossing technique is more effective than a program without crossing hands, in order to reduce pain. Material and method: Sixteen patients with chronic pain in elbow, wrist or hand, were randomized in two groups. One received transcutaneous electrical nerve stimulation (TENS) with hand crossing and closed eyes, and the other (control group) received only the application of TENS. Each group was evaluated before and after the intervention with the McGill pain questionnaire and the visual analog scale (VAS). Results: A decrease in post-intervention pain was observed in both groups; where the control group decreased an average of 3.5 cm and the experimental group 3.75 cm. All sessions of the experimental group were statistically significant (P = <0.05), while one session in the control group was not statistically significant (P = 0.051). However, the Analysis of variance (ANOVA) between both groups, did not give statistically significant (p = 0.863). Conclusions: The results do not show that the crossing of hands potentiates the effects of analgesic therapy on pain intensity. More information is the effects to include this technique as a support strategy in patients with chronic pain, and to manage sensory alterations and changes in the processing of information that reaches the periphery.

RESUMEN Antecedentes: Estudios recientes refieren que los pacientes con dolor crónico sufren cambios en el procesamiento de la información que les llega desde la periferia con el solo hecho de cambiar el orden en que los estímulos les son ejercidos, por ejemplo, cuando se les cruzan las manos. En los pacientes con dolor crónico se ha demostrado la presencia de alteraciones en sus marcos de referencia somatotópicos, y es por esto que la estrategia de cruzar las extremidades por la línea media, podría generar cambios en la percepción dolorosa. Objetivo: Evaluar si un programa de fisioterapia analgésica aplicada con cruce de manos es más eficaz que uno sin el cruce para disminuir el dolor. Material y método: 16 pacientes con dolor crónico de codo, muñeca o mano ingresaron al estudio. Fueron aleatorizados en un grupo experimental, que recibió la aplicación de electroanalgesia nerviosa transcutánea (TENS) con cruce de manos y ojos cerrados, además de un grupo control, que recibió solo electroanalgesia. A cada grupo se les evaluó su dolor pre y postintervención, con el cuestionario del dolor de McGill y la escala visual análoga (EVA). Resultados: Ambos grupos, el control y experimental, presentaron una disminución en el dolor postintervención; el grupo control disminuyó una media de 3,5 cm y el grupo experimental con una media de 3,75 cm. Todas las sesiones del grupo experimental fueron estadísticamente significativas (p < 0,05), mientras que el grupo control presentó una sesión no estadísticamente significativa (p = 0,051). El análisis de varianza (ANOVA) entre ambos grupos, sin embargo, no dio estadísticamente significativo (p = 0,863). Conclusiones: Los resultados no evidencian convincentemente que el cruce de manos potencia los efectos de la terapia analgésica en relación con la intensidad dolorosa. Más estudios serían necesarios para incluir esta técnica como una estrategia de apoyo en pacientes con dolor crónico, y poder manejar así las alteraciones sensoperceptivas y los cambios en el procesamiento de la información que les llega de la periferia.

Abstract Over the last years extensively research has been carried out on full or partial substitution of supplies resources coming from renewable resources on traditionally non-renewable, in the case of the automobile sector there are progresses in bio-combustibles (biofuel) and synthetic oils coming from vegetable sources. There are strong efforts to find oil additives which can improve oils features in automobile industry, by adding vegetables oils to commercial lubricant oils, is expected to improve oil thermal stability. In the present research, different ratios of castor oil (ricinus comunis)-motor oil blends were obtained and their thermal properties were characterized by using the so-called Back and Front Photopyroelectric (BPPE/FPPE) techniques. Several oil-additives concentrations were measured and thermal diffusivities and effusivities as well as densities are reported, getting full thermal characterization for every concentration.

Abstract Copper aluminate (CuAlO2) is a p-type semiconducting thermoelectric material that crystalize in delafosite phase at a temperature of 1100 °C. In this work, two samples were synthesized by Pechini method and calcined using two different procedures in order to determine the effect of thermal history on the phase formation and the thermoelectric properties. Sample M1 was calcined at 1100 °C after a termal treatment at 550 °C and the sample M2 was calcined at 1100 °C without previous treatment. Crystalline structure of obtained materials was analyzed by X-ray diffraction and bandgap energy obtained from Kubelka-Munk method applied to UV-Vis diffuse reflectance spectra. In sample M1 a mixture of spinel and delafossite phases was obtained and in sample M2 a mixture of Al2O3 and delafossite. Electrical conductivity, carrier density and Seebeck effect were measured from 100 °C to 800 °C, confirming that both samples are p-type semiconductors and their conductivity occurs from small polarons. It is shown that temperature ramp and pre-treatment affect the formation of secondary phases, which has a direct effect on thermoelectric properties of the material.

Resumen El aluminato de cobre (CuAlO2) es un material termoeléctrico semiconductor tipo-p, que cristaliza en fase delafosita a temperatura de 1100 °C. En este trabajo se sintetizaron dos muestras por el método Pechini y se calcinaron por dos procedimientos diferentes para determinar el efecto de la historia térmica en la formación de las fases y en las propiedades termoeléctricas. La muestra M1 se calcinó a 1100 °C después de un tratamiento térmico a 550 °C y la muestra M2 se calcinó a 1100 °C sin tratamiento térmico previo. La estructura cristalina de los materiales obtenidos se analizó por difracción de rayos X y el ancho de banda prohibida se obtuvo por el método de Kubelka-Munk a partir de los espectros de reflectancia difusa en el ultravioleta-visible. En la muestra M1 se tiene una mezcla de fases, espinela y delafosita y en la M2 se observa una mezcla de Al2O3 y delafosita. Se midió la conductividad eléctrica, la densidad de portadores y la movilidad de la muestra M2 por efecto Hall a temperatura ambiente, así como la conductividad eléctrica y el coeficiente Seebeck en un intervalo de temperaturas de 100 °C a 800 °C, confirmándose que las dos muestras son semiconductores tipo-p y que la conductividad ocurre por polarones pequeños. Se demuestra que las rampas de temperatura y pre tratamiento térmico tienen un efecto en la formación de fases secundarias, lo que afecta directamente las propiedades termoeléctricas del material.

Abstract: Photoacoustic Spectroscopy (PAS) stand outs among Photothermal techniques due to its versatility for the characterization of different types of materials, including biological samples. In this study, were compared and analyzed by PAS, the differences between the optical absorption spectra of blood of male Fisher rats, in three cases, control (healthy rats), liver damage and liver damage treated with Curcuma longa. The experimental results show differences in the optical absorption spectra of each analysed case, therefore PAS would be proposed as a non conventional complementary technique, to study the effect of Curcuma longa in induced liver damage for an animal model.

Resumen: La Espectroscopia Fotoacústica (EFA), ha destacado de entre las técnicas fototérmicas por su versatilidad para la caracterización de diversos tipos de muestras, incluyendo las de tipo biológicas. En este estudio, se compararon y analizaron mediante EFA, las diferencias entre los espectros de absorción ópticos de sangre de ratas macho Fisher en tres casos, control (ratas sanas), con daño hepático, y con daño hepático tratadas con Curcuma longa. Los resultados experimentales demostraron diferencias en los espectros de absorción ópticos de cada caso analizado, por lo que EFA se propondría como una técnica complementaria, no convencional para el estudio del efecto de la Curcuma longa en daño hepático inducido en modelo animal.

La fabricación de aleaciones en estado sólido tiene muchas diferencias con el proceso de fusión (colada) convencional. En el caso de la molienda de alta energía o aleado mecánico, las trasformaciones de fases de las materias primas son promovidas por una gran cantidad de energía que se introduce mediante impacto con medios de molienda; no hay fusión, pero sí cambios microestructurales que van desde refinamiento microestructural hasta amorfización en estado sólido. En este trabajo se estudia el comportamiento de metales puros (Cu y Ni) y diferentes aleaciones binarias (Cu-Ni y Cu-Zr) sometidas a las mismas condiciones de molienda con el objetivo de analizar el efecto del proceso en metales similares (Cu y Ni) y con solubilidades muy diferentes (Cu-Ni y Cu-Zr). Después de la molienda de alta energía, se analizaron los patrones de difracción de rayos X para determinar cambios en parámetros de red, y calcular las micro-deformaciones y el tamaño de las cristalitas, los cuales fueron calculados por el método de Williamson Hall (W-H), para luego ser comparados con los datos de las imágenes obtenidas por microscopia electrónica de transmisión (MET). Los cálculos muestran una apropiada similitud con las observaciones en MET; sin embargo, en general, las observaciones muestran heterogeneidades que no son consideradas en el método de W-H. De acuerdo a los resultados, en los metales puros se observó mayor cantidad de micro-deformaciones en níquel y fue más abrasivo que el cobre. En las aleaciones binarias, el sistema Cu-Ni formó soluciones sólidas con solubilidad total y las del sistema Cu-Zr mostraron amorfización, en función del contenido de Zr. Los métodos matemáticos no pueden ser aplicados en los casos donde se detecta amorfización debido a que aún no han sido creadas ecuaciones que representen este fenómeno cuando ocurre durante la molienda. Como conclusión se observó que bajo las mismas condiciones de molienda los resultados pueden ser muy diferentes debido al impacto significativo de la composición: el níquel formó fácilmente solución sólida mientras que el circonio incremento la habilidad de formación de vidrios.

The manufacture of alloys in solid state has many differences with the conventional melting (casting) process. In the case of high energy milling or mechanical alloying, phase transformations of the raw materials are promoted by a large amount of energy that is introduced by impact with the grinding medium; there is no melting, but the microstructural changes go from microstructural refinement to amorphization in solid state. This work studies the behavior of pure metals (Cu and Ni), and different binary alloys (Cu-Ni and Cu-Zr), under the same milling/mechanical alloying conditions. After high-energy milling, X ray diffraction (XRD) patterns were analyzed to determine changes in the lattice parameter and find both microstrain and crystallite sizes, which were first calculated using the Williamson-Hall (W-H) method and then compared with the transmission electron microscope (TEM) images. Calculations showed a relatively appropriate approach to observations with TEM; however, in general, TEM observations detect heterogeneities, which are not considered for the W-H method. As for results, in the set of pure metals, we show that pure nickel undergoes more microstrain deformations, and is more abrasive than copper (and copper alloys). In binary systems, there was a complete solid solution in the Cu-Ni system and a glass-forming ability for the Cu-Zr, as a function of the Zr content. Mathematical methods cannot be applied when the systems have amorphization because there are no equations representing this process during milling. A general conclusion suggests that, under the same milling conditions, results are very different due to the significant impact of the composition: nickel easily forms a solid solution, while with a higher zirconium content there is a higher degree of glass-forming ability.

Objective: To determine the optimal method to collect platelet-rich plasma (PRP). Material and methods: We collected 15 ml of blood from 36 healthy adults to determine platelet count and to test which of the following three protocols were the best to collect PRP. We used 3 ml of blood for each method: protocol 1: (n = 21) the blood tube was tested at 1200 revolutions per minute (RPM) in 2 centrifuge cycles of 8 minutes each; protocol 2 (n = 8): 1200 RPM/1 cycle/8 minutes, and protocol 3: (n = 7): 1200 RPM/1 cycle/10 minutes. From the blood samples that we collected, we also analyzed 1 ml of plasma to determine platelet performance by using an automatic flow cytometer (BD FACSCanto II). Platelet performance was determined by the following formula: platelet PRP count (100)/platelet count from total blood. The statistical method used were measures of central tendency, Chi-square, t-test, analysis of variance and the Wilcoxon and Kruskal-Wallis tests. Results: The basal overall count of platelet was 261.2 miles/mcl for the three methods (p = 0.906), 662.3 ± 243.3 (p = 0.001) for protocol 1; 377.9 ± 101.4 (p = 0.008) for protocol 2 and 30.9 ± 18.8 (p = 0.016) for protocol 3. Platelet performances were 255.2 ± 57.6 %; 149.3 ± 24.6 %; 13.3 ± 11.6 % respectively. Conclusion: Applying the first protocol we obtain PRP (1200 RPM/2 cycles of 8 minutes each). This study was done in healthy adults; however, future studies with a larger sample size are needed to confirm our findings of this method. In case of collecting platelets in studies with greater population being the adequate, its clinical utility should be validated by including patients with chronic and degenerative diseases and take care of associated diseases.

Objetivos: Describir el método óptimo para obtener plasma rico en plaquetas (PRP). Material y métodos: Previo consentimiento informado, se obtuvieron de 36 pacientes sanos una muestra sanguínea de 15 ml distribuidos en 5 tubos estériles: uno para obtención de biometría hemática y el resto se sometieron a alguno de los 3 protocolos para obtención de plasma rico en plaquetas. Protocolo 1 (n = 21): 1200 rpm/2 ciclos/8 minutos (cada ciclo); protocolo 2 (n = 8): 1200 rpm/1 ciclo de centrifugado/8 minutos. Protocolo 3 (n = 7): 1200 rpm/1 ciclo de centrifugado/10 minutos. De las muestras obtenidas, se analizó 1 ml de plasma mediante citómetro de flujo automatizado (BD FACSCanto II) y se determinó el rendimiento plaquetario mediante la fórmula: recuento de plaquetas PRP (100)/recuento de plaquetas de sangre total. El método estadístico empleado fue medidas de tendencia central, Chi cuadrado, t de Student, análisis de varianza, prueba de Wilcoxon y probabilidad de Kruskal-Wallis. Resultados: El promedio de concentración basal plaquetaria fue de 261.2 miles/mcl para los 3 métodos (p = 0.906). Después del proceso de centrifugado para protocolo 1 fue 662.3 ± 243.3 (p = 0.001); protocolo 2, 377.9 ± 101.4 (p = 0.008) y 30.9 ± 18.8 (p = 0.016) para el 3. El rendimiento fue: 255.2 ± 57.6 %; 149.3 ± 24.6 %; 13.3 ± 11.6 %, respectivamente. Conclusión: Se logró obtener PRP aplicando el primer protocolo (1200 rpm/2 ciclos/8 minutos cada ciclo). El estudio se realizó en pacientes adultos sanos, sin embargo, se tendrán que realizar estudios posteriores con una mayor población para comprobar la efectividad de este método. En caso de que la obtención plaquetaria en estudios con mayor población sea la adecuada, deberá validarse su utilidad clínica en paciente con enfermedades crónico degenerativas y se tomen en cuenta las enfermedades concomitantes.

Abstract The Impulse Oscillometry System (IOS) has been recognized as a useful diagnostic tool. Previous research by our group has shown that R5 (Resistance at 5 Hz), R5-R20 (frequency dependence of resistance), AX (the "Goldman Triangle") and the extended Resistor-Inductor-Capacitor (eRIC) model-derived parameter Cp (peripheral Compliance) are reliable measures that track respiratory system function. Here we determined the predictive equations from 112 asthmatic and non-asthmatic Anglo and Hispanic children data, that were previously classified into four groups: Normal, PSAI (Probable Small Airway Impairment), SAI (Small Airway Impairment), and Asthma by using regression analysis of IOS and eRIC model parameters as dependent variables regressed against age, height, and weight. Height showed the greatest correlation with IOS and eRIC model parameters and provided the most significant reference values for these measures in Anglo and Hispanic children. These values could serve as a useful framework for diagnosis, early interventions, and treatment of respiratory diseases in this population.

Resumen El Sistema de Oscilometría Impulsos (por sus siglas en Inglés: IOS) ha sido reconocido como una herramienta de diagnóstico útil. Investigaciones previas realizadas por nuestro grupo han demostrado que R5 (Resistencia a 5 Hz), R5-R20 (dependencia a la frecuencia de la resistencia), AX (el "Triángulo de Goldman") y el párametro Cp (Capacitancia periférica) derivado del modelo extendido Resistencia-inductor-condensador (eRIC) son medidas fiables que monitorean la función del sistema respiratorio. El presente estudio determina las ecuaciones de predicción de 112 niños Anglo e Hispanos asmáticos y no asmáticos, que previamente clasificados en cuatro grupos: Normal, PSAI (por su nombre en inglés: Probable daño en las vías aéreas menores), SAI (por su nombre en inglés: Daño en las vías aéreas menores), y Asma. Las ecuaciones de predicción se determinaron mediante análisis de regresión de parámetros del IOS y del modelo eRIC (variables dependientes) contra edad, estatura y peso. La estatura mostró la mejor correlación con los parámetros del IOS y del modelo eRIC, proporcionando los valores de referencia más significativos para estas medidas en niños Anglos e Hispanos. Estos valores podrían servir como un marco de referencia útil para el diagnóstico, intervenciones tempranas, y tratamiento de las enfermedades respiratorias en esta población.