Selenium nanoparticles based on Amphipterygium glaucum extract with antibacterial, antioxidant, and plant biostimulant properties.

BACKGROUND: In recent years, crop production has expanded due to the variety of commercially available species. This increase in production has led to global competition and the search for biostimulant products that improve crop quality and yield. At the same time, agricultural products that protect against diseases caused by phytopathogenic microorganisms are needed. Thus, the green synthesis of selenium nanoparticles (SeNPs) is a proposal for achieving these needs. In this research, SeNPs were synthesized from methanolic extract of Amphipterygium glaucum leaves, and chemically and biologically characterized. RESULTS: The characterization of SeNPs was conducted by ultraviolet-visible spectrophotometry (UV-Vis), scanning electron microscopy (SEM), electron microscopy transmission (TEM), Dynamic Light Scattering (DLS), energy dispersion X-ray spectroscopy (EDX), and infrared spectrophotometry (FTIR) techniques. SeNPs with an average size of 40-60 nm and spherical and needle-shaped morphologies were obtained. The antibacterial activity of SeNPs against Serratia marcescens, Enterobacter cloacae, and Alcaligenes faecalis was evaluated. The results indicate that the methanolic extracts of A. glaucum and SeNPs presented a high antioxidant activity. The biostimulant effect of SeNPs (10, 20, 50, and 100 µM) was evaluated in vinca (Catharanthus roseus), and calendula (Calendula officinalis) plants under greenhouse conditions, and they improved growth parameters such as the height, the fresh and dry weight of roots, stems, and leaves; and the number of flowers of vinca and calendula. CONCLUSIONS: The antibacterial, antioxidant, and biostimulant properties of SeNPs synthesized from A. glaucum extract demonstrated in this study support their use as a promising tool in crop production.

Novel adaptive law for super-twisting controller: USV tracking control under disturbances.

A novel adaptive super-twisting control algorithm, for Unmanned Surface Vehicles (USV) tracking control is presented. The proposed adaptive law is obtained using a Lyapunov approach, to analyze the system closed-loop stability. Furthermore, several conditions are given to guarantee robustness in presence of unknown bounded disturbances/uncertainties, chattering mitigation and the finite-time convergence. This adaptive control strategy has the advantage that the controller gains, which are in terms of a single control parameter, requires adjusting a small number of parameters compared with other adaptive strategies, moreover and its dynamics is smooth, improving the controller performance. To assess the proposed control methodology effectiveness, a trajectory tracking control is designed and implemented on an unmanned surface vehicle under the action of bounded unknown uncertainties and external perturbations. Numerical simulations and experimental results conducted with a vessel prototype demonstrate the performance and advantages under payload variations and external environmental conditions. Finally, a comparative study between the proposed approach with other adaptive super-twisting works has been conducted.

Adaptive sensorless control for interior permanent magnet synchronious motor based on sliding mode approach.

This paper proposes an adaptive sensorless control based on sliding mode approach for Interior Permanent Magnet Synchronous Motor (IPMSM) using the method of the angular position estimation error extraction. The proposed strategy combines a novel Adaptive Super-Twisting Controller (ASTWC) with a novel Adaptive Observer High-Order Sliding Mode (AOHOSM), where: (i) The control and observer gains are parameterized in terms of a single parameter simplifying its implementation and reducing the tuning time. (ii) By using an auxiliary system, which does not depend on machine parameters, an AOHOSM is designed for estimating the angular position, speed and acceleration in a wide speed range of the IPMSM, (iii) and these are used in an ASTWC to track a desired reference of speed and direct-axis current. (iv) Sufficient conditions are given to ensure the stability of the closed-loop system using a Lyapunov approach. Furthermore, the proposed strategy is validated throughout experimental set-up in order to show its effectiveness. Finally, a comparative study between the proposed strategy and other strategies published in the literature is addressed.

Antifungal Activity of Selenium Nanoparticles Obtained by Plant-Mediated Synthesis.

The continuous need to satisfy world food demand has led to the search for new alternatives to combat economic losses in agriculture caused by phytopathogenic fungi. These organisms cause plant diseases, reducing their productivity and decreasing fruit quality. Among the new tools being explored is nanotechnology. Nanoparticles with antimicrobial properties could be an excellent alternative to address this problem. In this work, selenium nanoparticles (SeNPs) were obtained using plant extracts of Amphipterygium glaucum leaves (SeNPs-AGL) and Calendula officinalis flowers (SeNPs-COF). Characterization of the SeNPs was performed and their ability as antifungal agents against two commercially relevant plant pathogenic fungi, Fusarium oxysporum and Colletotrichum gloeosporioides, was evaluated. Assays were performed with different concentrations of SeNPs (0, 0.25, 0.5, 1.0, and 1.7 mg/mL). It was observed that both SeNPs had antifungal activity against both plant pathogens at concentrations of 0.25 mg/mL and above. SeNPs-AGL demonstrated better antifungal activity and smaller size (around 8.0 nm) than SeNPs-COF (134.0 nm). FTIR analysis evidenced the existence of different functional groups that constitute both types of SeNPs. There are factors that have to be considered in the antimicrobial activity of SeNPs such as nanoparticle size and phytochemical composition of the plant extracts used, as these may affect their bioavailability.

Comparative study of steroidal sapogenins content in leaves of five Agave species.

BACKGROUND: Agaves are mainly used to produce alcoholic beverages such as tequila, mezcal and bacanora. However, the leaves constitute more than 50% of the plant and are not used in the production process, so they are considered waste. This plant material can be used as a source of bioactive compounds such as terpenes, flavonoids and saponins. Therefore, the objective of this study was to characterize the aglycone type of saponins and to quantify three steroidal sapogenins in leaves of five Agave species collected in different regions of Guerrero and Oaxaca, Mexico. RESULTS: Analysis by gas chromatography-flame ionization detection of the hydrolyzed methanolic extracts showed that diosgenin and tigogenin were the most abundant sapogenins identified in the five Agave species. Differences in the content of these sapogenins were found in the same species collected in different localities. The leaves of Agave americana var. oaxacensis L. (Oaxaca) had the highest diosgenin-derived saponin content, while the leaves of A. angustifolia Haw. (Guerrero) had the highest tigogenin-derived saponin content. Only in A. cupreata was sarsasapogenin identified, all three sapogenins occurring in the leaves of this species. For the first time, information is provided on the aglycones of the saponins produced in A. potatorum Zucc. and A. karwinskii Zucc. CONCLUSION: This study made it possible to compare the content of diosgenin and tigogenin-derived saponins in leaves of Agave species from Guerrero and Oaxaca. This information will be useful for better utilization of this plant material and add value to the process of mezcal elaboration. © 2022 Society of Chemical Industry.

The Role of Selenium Nanoparticles in Agriculture and Food Technology.

Selenium (Se) is an essential micronutrient for diverse organisms such as mammals, bacteria, some insects and nematodes, archaea, and algae, as it is involved in a large number of physiological and metabolic processes and is part of approximately 25 selenoproteins in mammals. In plants, Se has no essential metabolic role, high concentrations of inorganic Se can lead to the formation of Se-amino acids, and its incorporation into selenoproteins can generate toxicity. Conversely, low doses of Se can trigger a variety of beneficial effects as an antioxidant, antimicrobial, or stress-modulating agent without being an essential element. Therefore, Se can generate toxicity depending on the dose and the chemical form in which it is supplied. Selenium nanoparticles (SeNPs) have emerged as an approach to reduce this negative effect and improve its biological properties. In turn, SeNPs have a wide range of potential advantages, making them an alternative for areas such as agriculture and food technology. This review focuses on the use of SeNPs and their different applications as antimicrobial agents, growth promoters, crop biofortification, and nutraceuticals in agriculture. In addition, the utilization of SeNPs in the generation of packaging with antioxidant and antimicrobial traits and Se enrichment of animal source foods for human consumption as part of food technology is addressed. Additionally, possible action mechanisms and potential adverse effects are discussed. The concentration, size, and synthesis method of SeNPs are determining factors of their biological properties.

Antibacterial Activity of Biosynthesized Selenium Nanoparticles Using Extracts of Calendula officinalis against Potentially Clinical Bacterial Strains.

The use of selenium nanoparticles (SeNPs) in the biomedical area has been increasing as an alternative to the growing bacterial resistance to antibiotics. In this research, SeNPs were synthesized by green synthesis using ascorbic acid (AsAc) as a reducing agent and methanolic extract of Calendula officinalis L. flowers as a stabilizer. Characterization of SeNPs was performed by UV-vis spectrophotometry, infrared spectrophotometry (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM) techniques. SeNPs of 40-60 nm and spherical morphologies were obtained. The antibacterial activity of marigold extracts and fractions was evaluated by disk diffusion methodology. The evaluation of SeNPs at different incubation times was performed through the colony-forming unit (CFU) count, in both cases against Serratia marcescens, Enterobacter cloacae, and Alcaligenes faecalis bacteria. Partial antibacterial activity was observed with methanolic extracts of marigold leaves and flowers and total inhibition with SeNPs from 2 h for S. marcescens, 1 h for E. cloacae, and 30 min for A. faecalis. In addition, SeNPs were found to exhibit antioxidant activity. The results indicate that SeNPs present a potentiated effect of both antimicrobial and antioxidant activity compared to the individual use of marigold extracts or sodium selenite (Na2SeO3). Their application emerges as an alternative for the control of clinical pathogens.

T Cell Predominant Response to AAV-Spike Protects hACE2 Mice from SARS-CoV-2 Pneumonia

Prevention of COVID-19 is widely believed to depend on neutralization of SARS-CoV-2 by vaccine-induced humoral immunity1,2, raising concern that emerging escape variants may perpetuate the pandemic3-6. Here we show that a single intramuscular injection of Adeno-Associated Virus-6 (AAV6) or AAV9 encoding a modified, N-terminal domain deleted ({Delta}NTD) spike protein induces robust cellular immunity and provides long-term protection in k18-hACE2 transgenic mice from lethal SARS-CoV-2 challenge, associated weight loss and pneumonia independent of vaccine-induced neutralizing humoral immunity. In both mice and macaques, vaccine-induced cellular immunity results in the clearance of transduced muscle fibers coincident with macrophage and CD8+ cytotoxic T cell infiltration at the site of immunization. Additionally, mice demonstrate a strong Type-1 polarized cellular immunophenotype and equivalent ex vivo T cell reactivity to peptides of wt and alpha (B.1.1.7) variant spike. These studies demonstrate not only that AAV6 and AAV9 can function as effective vaccine platforms, but also that vaccines can provide long-term efficacy primarily through the induction of cellular immunity. The findings may provide an alternative approach to containment of the evolving COVID-19 pandemic and have broader implications for the development of variant-agnostic universal vaccines against a wider range of pathogens.

Assessment of mandibular kinematics values and its relevance for the diagnosis of temporomandibular joint disorders.

BACKGROUND/PURPOSE: Temporomandibular disorders (TMD) are common conditions that involve the temporomandibular joints (TMJs), jaw muscles, or both, and can cause alteration in the mandibular kinematics. The aim of this study was to assess the relationship between mandibular kinematics and temporomandibular joint disorders (TMJD) as a clinical tool for evaluation and diagnosis of these patients. MATERIALS AND METHODS: A retrospective study based on the analysis of the clinical findings from patients' charts was carried out, with a sample size of 476 patients. Statistical analysis was made with chi-square test for qualitative variables and student t-test for quantitative variables. Then, odds ratio with its confidence interval were calculated. A p value < 0.05 was considered statistically significant. RESULTS: Most patients were female (80.7%) and between 16 and 25 years old. Disc displacement with reduction (DDwR) and subluxation were associated with increased kinematic parameters, while disc displacement without reduction (DDwoR) and retrodiscitis were associated with decreased kinematic values. A soft end feel was related to osteoarthritis (OA). Structural incompatibility was most prevalent in older patients. CONCLUSION: Mandibular kinematic values are associated with specific temporomandibular joint disorders and could be considered as a useful clinical tool to perform the right diagnosis of TMJD.

Plant-mediated synthesis of nanoparticles and their antimicrobial activity against phytopathogens.

Nanotechnology is an emerging science with a wide array of applications involving the synthesis and manipulation of materials with dimensions in the range of 1-100 nm. Nanotechnological applications include diverse fields such as pharmaceuticals, medicine, the environment, food processing and agriculture. Regarding the latter, applications are mainly focused on plant growth and crop protection against plagues and diseases. In recent years, the biogenic reduction of elements such as Ag, Au, Cu, Cd, Al, Se, Zn, Ce, Ti and Fe with plant extracts has become one of the most accepted techniques for obtaining nanoparticles (NPs), as it is considered an ecological and cost-effective process without the use of chemical contaminants. The objective of this work was to review NPs synthesized by green chemistry using vegetable extracts, as well as their use as antimicrobial agents against phytopathogenic fungi and bacteria. Given the need for alternatives to control and integrate management of phytopathogens, this review is relevant to agriculture, although this technology is barely exploited in this field. © 2020 Society of Chemical Industry.

State and parameter estimation for a class of Nonlinear Systems based on Sliding Mode Approach.

In this paper, simultaneous state estimation and parameters identification for a class of nonlinear systems are addressed. With the aim of solving this problem, an adaptive observer based on the sliding mode (AOSM) approach is designed. The main advantage of the proposed adaptive observer design is that it combines the robustness and finite time convergence of the sliding mode observers, with the simplicity of tuning of high-gain observers, reducing tuning effort. The finite time convergence of the proposed adaptive observer is established using a Lyapunov approach. Furthermore, a comparative study of the proposed adaptive observer against schemes from literature is presented, in order to show the advantages of the proposed approach. Finally, numerical results are provided to demonstrate the effectiveness and performance of the proposed approach under noise and external disturbances.

Observer-based super twisting design: A comparative study on quadrotor altitude control.

This paper addresses the design of a continuous super twisting control combined with a high-order sliding mode observer for a class of nonlinear systems. An analysis of closed-loop stability is provided by means of Lyapunov approach, where sufficient conditions are given to ensure the convergence and to select the gains of the proposed controller. Numerical simulation and experimental results illustrate the performance of the proposed control-observer scheme for controlling the altitude of a quad-rotor aircraft. Furthermore, a comparative study against similar approaches from literature is included for illustrating that proposed methodology requires less control effort while shows the best performance.

Estimulación nerviosa eléctrica transcutánea como complemento a la terapia convencional en pacientes con trastornos temporomandibulares: un estudio caso-control / Transcutaneous electrical nerve stimulation as a complement to conventional therapy in patients with temporomandibular disorders: a case-control study

INTRODUCCIÓN: Para los trastornos temporomandibulares (TTM) el tratamiento de primera línea es el conservador, éste incluye a la terapia convencional, además se ha descrito el uso de la estimulación nerviosa eléctrica transcutánea (TENS). El objetivo de este estudio fue determinar la respuesta terapéutica del TENS como complemento a la terapia convencional comparado con pacientes que recibieron exclusivamente terapia convencional. MATERIAL Y MÉTODOS: Estudio retrospectivo caso-control en pacientes diagnosticados con TTM, tratados en la Clínica de Especialidades de la Escuela de Odontología de la Universidad de Valparaíso, entre los años 2009 y 2012. De los 231 pacientes, 63 cumplieron con los criterios de inclusión y fueron pareados en un grupo convencional y un grupo TENS. Se evaluó el dolor articular y muscular; aperturas mandibulares activa sin dolor, activa forzada y pasiva; y fuerza masticatoria. Se aplicaron test estadísticos de Kruskal-Wallis, Wilcoxon y Spearman. RESULTADOS: Para el grupo TENS, se encontraron respuestas significativas en dolor articular y muscular derecho e izquierdo, apertura mandibular activa sin dolor y fuerza masticatoria. Para el grupo convencional, se encontraron resultados similares a excepción de dolor articular derecho. También respuestas significativas para todas las variables que midieron dolor inmediatamente posterior a la aplicación de TENS. Finalmente se establecieron correlaciones entre la edad y las aperturas activa sin dolor, activa forzada y pasiva. DISCUSIÓN: La terapia convencional y la complementada con TENS demostraron similar respuesta terapéutica a largo plazo, sin embargo, la aplicación del TENS produce una respuesta inmediata que reduce el dolor en el corto plazo

INTRODUCTION: For temporomandibular disorders (TMD), conservative therapies, including conventional therapy, are the first line of treatment, and the use of transcutaneous electrical nerve stimulation (TENS) has also been reported. The aim of this study was to determine the therapeutic response to TENS as complement to conventional therapy compared with patients receiving conventional therapy exclusively. METHODOLOGY: A retrospective study was carried out with patients diagnosed with TMD, treated at the Clinic of Specialties of the Dental School of Universidad de Valparaíso, between 2009 and 2012. Of 231 patients, 63 met the inclusion criteria and were randomly allocated to a conventional therapy group (controls) and a coadjuvant TENS group (cases). Both were evaluated for pain in the temporomandibular joints (TMJ) and masseters, active opening without pain, forced active opening, passive opening, and occlusal force. Statistical analysis was performed with Kruskal-Wallis, Wilcoxon and Spearman tests. RESULTS: For TENS group, significant differences were found for pain in the right and left TMJ, pain in the right and left masseter, active opening without pain, and occlusal force. For the conventional group, the same results were obtained, except for pain in right TMJ. For the variables measured immediately after applying TENS, significant differences were found in all pain variables. Correlations were established with age, active opening without pain, forced active opening, and passive opening. DISCUSSION: Conventional therapy and TENS-complemented therapy showed good therapeutic response, concluding that TENS is a good complement to conventional therapy

Revisión: necesidades nutricionales de peces de la familia Pimelodidae en Sudamérica (Teleostei: Siluriformes)

Los silúridos, también conocidos como bagres, es uno de los grupos más representativos de peces. Conformado por 31 familias, 412 géneros y 2 600 especies aproximadamente, por lo que se ubica, en extensión, como el tercero entre todos los órdenes de teleósteos de los cuales 13 familias (64 % de las especies) residen en sur América. Dentro de este orden se encuentra la familia Pimelodidae, Eigenmann y Eigenmann (1889), siendo la más abundante en siluriformes neotropicales distribuidos ampliamente en América del Sur y Central. Algunos representantes de la familia Pimelodidae son individuos cuyas características específicas los hacen aptos para ser manejados en cautividad con fines comerciales. Uno de los principales factores negativos para hacer rentable este ejercicio comercial es la falta de conocimiento relacionado, entre otras cosas, con los elementos básicos que permitan formular dietas alimenticias bien equilibradas y que aporten al individuo los requerimientos nutricionales básicos para un óptimo desarrollo. Es por lo anterior, que se requiere realizar una recopilación bibliográfica general de los principales aspectos relacionados con la alimentación y nutrición de esta familia.

Nutritional requirements of Pimelodidae fishes in South America (Teleostei: Siluriformes). The Silurids, also known as catfish is one of the most representative groups of fish. Comprised of 31 families, 412 genera and approximately 2 600 species, which places them, as the third among all orders of teleost of which 13 families (64 % of the species) living in South America. Within this order is the Pimelodidae, Eigenmann and Eigenmann family (1889), the most abundant in Neotropical siluriformes widely distributed in South and Central America. Some representatives of the Pimelodidae family are individuals whose specific characteristics make capable of being handled in captivity for commercial purposes. One of the main negative factors for profitable business is the lack of knowledge about, among other things, the basic elements to formulate well-balanced diets and to provide the fish with their basic nutritional requirements for an optimal development. For this reason, it is of paramount importance to make a general bibliography review of the main aspects related to food and nutrition of the family.

[Acetylsalicylic acid in prevention of pre-eclampsia]. / Prevención de la preeclampsia con ácido acetilsalicílico.

BACKGROUND: Pre-eclampsia (PE) is an important cause of morbidity and mortality in our country. OBJECTIVE: Evaluate if the administration of acetylsalicylic acid (ASA) at a low dose reduces its presence. METHODS: Comparative, cohort study. Pregnant women with risk factors for PE: Primigravidae, PE antecedent and twin pregnancy were included. Primigravidae and multigested with previous vascular pathology weren't included. Group 1: 150, 11 excluded, 80 mg ASA from week 20 at the end of pregnancy. Group 2: 150, without ASA. The presence of PE or gestational hypertension (HG) was monitored. General data and clinical controls were taken. Chi square and relative risk (RR) were calculated. RESULTS: Group 1: n = 139, 26 ± 5.6 years, 9% PE. Group 2: n = 150, 25.5 ± 5.6 years, PE 20% (p = 0.01), RR 0.47 (95% CI 0.19 - 0.87) (p = 0.01), attributable risk -0.11 equivalent to an absolute reduction of 11% for PE in group 1. CONCLUSIONS: Pregnant women with risk factor for PE who received ASA diminished the risk of developing PE in 50%.

INTRODUCCIÓN: los trastornos hipertensivos del embrazo son causa importante de morbilidad grave, discapacidad crónica y muerte entre las madres, fetos y recién nacidos, por lo que es necesaria la prevención de la preeclampsia (PE) en virtud de su alta morbimortalidad en México. OBJETIVO: evaluar si la administración de ácido acetilsalicílico (AAS) a dosis baja reduce la presencia de PE. MÉTODOS: estudio de cohorte, comparativo. Se incluyeron 300 mujeres embarazadas con factores de riesgo para PE: primigesta, antecedente de PE, embarazo gemelar. No se incluyeron las pacientes primigestas y multigestas con patología vascular previa. Grupo 1: 150, 11 excluidas, 80 mg AAS de semana 20 al final del embarazo. Grupo 2: 150, sin AAS. Se vigiló presencia de PE o hipertensión gestacional (HG). Se tomaron datos generales y controles clínicos. Se calculó Chi cuadrada y riesgo relativo (RR). RESULTADOS: grupo 1: 139, 26 ± 5.6 años, PE en 9%. Grupo 2: 150, 25.5 ± 5.6 años, PE 20% (p = 0.01). RR 0.47 (IC95%: 0.19 - 0.87) (p = 0.01), riesgo atribuible de -0.11 equivalente a una reducción absoluta del 11% para PE en grupo 1. CONCLUSIONES: en mujeres embarazadas con factores de riesgo para PE que recibieron AAS, disminuye de forma significativa el riesgo de probabilidad de desarrollar PE a menos de la mitad.

Estrategia pedagógica para la formación ética del profesor de levantamiento de pesas en Pinar del Río / Pedagogical Strategy for the ethic formation of the Weightlifting professor in Pinar del Río, Cuba

RESUMEN La investigación está dirigida a fundamentar una estrategia pedagógica para los profesores deportivos de levantamiento de pesas en la provincia de Pinar del Río, que contribuya a la preparación ética en su desempeño profesional de manera competente y comprometida con el proyecto social cubano. El diagnóstico refleja debilidades en este proceso, por lo cual se hace necesario dotar a los mismos de las herramientas teórica-prácticas con el propósito de minimizar las deficiencias encontradas. La estrategia pedagógica se sustenta en los pilares de la formación ética para el proceso del entrenamiento deportivo, la profesionalidad pedagógica, la ética profesional y las cualidades éticas, teniendo presente las nuevas exigencias de este deporte a nivel internacional y en el contexto deportivo cubano. Se estructuró una estrategia pedagógica, conformada por etapas, basada en el método Dialéctico-Materialista. En el desarrollo de la investigación se emplearon métodos de nivel teórico, empírico y matemáticos-estadísticos. Mientras, para valorar la validez teórica de la estrategia pedagógica, se utilizó el Criterio de Expertos (Método Delphy). La factibilidad desde el punto de vista práctico se constató a partir del pre-experimento. Los resultados obtenidos reflejaron que la estrategia contribuyó al perfeccionamiento de la formación ética del profesor de levantamiento de pesas en la provincia de Pinar del Río.

ABSTRACT This research is aimed at establishing a pedagogical strategy on behalf of the sport professors on Weightlifting at the province Pinar del Río to contribute to the ethic formation in his professional performance competitively and engaged to the Cuban social project. This project reflects weakness in this process, that´s why it is necessary the provision of theoretical and practical tools to tackle this insufficiency, this strategy is based on the components of the ethic formation in sport training; the ethic professionalism, the professional ethic and the ethic quality, taking into account the new demands of this sport worldwide and according to the Cuban sport context. It is structured by a pedagogical strategy composed of stages, based on the dialectical-materialist method. In this research it was carried out theoretical, empirical and mathematical-statistical methods to value the theoretical validity of this strategy. It was used the expert criteria (Delphy method), The practical feasibility was confirmed through a pre-experiment. The outcomes reflect that the strategy contributed to the improvement of the ethic formation in the weightlifting professor at the province Pinar del Río, showing its theoretical validity.

Extended observer based on adaptive second order sliding mode control for a fixed wing UAV.

This paper addresses the design of attitude and airspeed controllers for a fixed wing unmanned aerial vehicle. An adaptive second order sliding mode control is proposed for improving performance under different operating conditions and is robust in presence of external disturbances. Moreover, this control does not require the knowledge of disturbance bounds and avoids overestimation of the control gains. Furthermore, in order to implement this controller, an extended observer is designed to estimate unmeasurable states as well as external disturbances. Additionally, sufficient conditions are given to guarantee the closed-loop stability of the observer based control. Finally, using a full 6 degree of freedom model, simulation results are obtained where the performance of the proposed method is compared against active disturbance rejection based on sliding mode control.

A Preliminary Study on qEEG in Burn Patients With Chronic Pruritus

OBJECTIVE: To explore and determine the reorganizational changes in the cortical neural circuits associated with pruritis, this study was undertaken to compare the electroencephalography (EEG) changes in burn patients having primary symptoms of chronic itching (pruritis) and their paired healthy subjects. METHODS: Eight subjects were recruited for this exploratory pilot study: 4 patients with pruritus after burn injury matched by gender and age with 4 healthy subjects. EEG recordings were analyzed for absolute alpha, low beta, high beta, and theta power for both groups. RESULTS: The mean age of the burn patients was 41.75 years; while the mean age for the matched healthy subjects was 41.5 years. All subjects were male. A decreased alpha activity was observed in the occipital channels (0.82 vs. 1.4; p=0.01) and a decreased low beta activity in the frontal area (0.22 vs. 0.4; p=0.049) in eyes closed conditions. An overall decreased theta trend was observed in both the eyes open and eyes closed conditions in burn patients, compared to healthy individuals. CONCLUSION: This preliminary study presents initial evidence that chronic pruritus in burn subjects may be associated with brain reorganizational changes at the cortical level characterized by an EEG pattern.

[Pulmonary function assessment in juvenile idiopathic scoliosis managed with posterior instrumentation with a sublaminar hook system]. / Evaluación de la función pulmonar en escoliosis idiopática del adolescente manejado con instrumentación posterior con sistema de ganchos sublaminares.

INTRODUCTION: Scoliosis is a spine deformity diagnosed using Cobbs method when the AP X-ray view shows an angulation greater than 10º. Scoliosis exceeding 50º results in restrictive pulmonary alterations. Surgical management improves the angulation and the pulmonary restrictive process. The pre- and post-operative pulmonary function values were compared using spirometry. MATERIAL AND METHODS: 27 patients of both genders, ages 11-15 years, underwent corrective surgery using posterior instrumentation with sublaminar hooks, rods and posterolateral arthrodesis. Spirometry was done preoperatively and six months after the surgery. Patients without a postoperative spirometry and/or a postoperative episode of pulmonary infection were excluded. The pre- and postoperative Cobb index was calculated. Spirometry: lung function at forced vital capacity (FVC) and forced expiratory volume in one second (FEV1). Descriptive statistics, Student t test. RESULTS: Females, 78%; males, 22%; 13.7 ± 1.22 years. Cobb method 40 - 110º, preoperative angle 64.48 ± 17.79º and postoperative angle 30.44 ± 10.90º. There were no 0º values. Lung function: preoperative FVC for the values of the scoliosis curve (p 0.0001) and significant marginal FEV1 (p = 0. Baseline: 40.6-122.0%, mean: 76.3 ± 18.8%, postoperative: 40.75-112.6%, mean: 76.5 ± 16.8%. Preoperative FEV1: 39.8-111.59%, mean: 73.9 ± 16.8%, postoperative: 42.86-120.79%, mean: 69.7 ± 16.5. The difference was statistically significant, 0.064). CONCLUSIONS: The sublaminar hook system with a posterior approach provides improvement of the idiopathic scoliosis curve of adolescents assessed with the Cobb method. It stops the progression of lung function impairment, with a significant improvement in forced expiratory volume in one second.

La escoliosis es una deformidad de la columna vertebral; se diagnostica por el método de Cobb presentando una angulación mayor de 10º en proyección radiográfica anteroposterior. Produce alteraciones pulmonares de tipo restrictivo en angulaciones mayores a 50º. Su manejo puede ser quirúrgico, mejorando la angulación y el proceso restrictivo pulmonar. Se comparó la función pulmonar pre- y postquirúrgica con espirometría.

Evaluación de la función pulmonar en escoliosis idiopática del adolescente manejado con instrumentación posterior con sistema de ganchos sublaminares / Pulmonary function assessment in juvenile idiopathic scoliosis managed with posterior instrumentation with a sublaminar hook system

Resumen: Introducción: La escoliosis es una deformidad de la columna vertebral; se diagnostica por el método de Cobb presentando una angulación mayor de 10o en proyección radiográfica anteroposterior. Produce alteraciones pulmonares de tipo restrictivo en angulaciones mayores a 50o. Su manejo puede ser quirúrgico, mejorando la angulación y el proceso restrictivo pulmonar. Se comparó la función pulmonar pre- y postquirúrgica con espirometría. Material y métodos: 27 pacientes, cirugía correctiva mediante instrumentación posterior con ganchos sublaminares, barras y artrodesis posterolateral. Ambos géneros. 11-15 años. Espirometría prequirúrgica y postquirúrgica a los seis meses. Fueron excluidos quienes carecían de espirometría postquirúrgica y/o aquéllos con evento infeccioso pulmonar postquirúrgico. Índice de Cobb, pre- y postquirúrgico. Espirometría: función pulmonar, la capacidad vital forzada (VCF) y el volumen espiratorio forzado en un segundo (FEV1). Estadística descriptiva, t Student. Resultados: Femenino 78% y masculino 22%, 13.7 ± 1.22 años. Método de Cobb 40 a 110o; prequirúrgico, 64.48 ± 17.79o y postquirúrgico, 30.44 ± 10.90o. No hubo valor de 0o. Capacidad pulmonar: prequirúrgico VCF para los valores de la curva de escoliosis (p < 0.0001) y significativa marginal para FEV1 (p = 0; inicial 40.6-122.0%, media 76.3 ± 18.8%; postquirúrgico 40.75-112.6%, media 76.5 ± 16.8%. FEV1 prequirúrgico 39.83-111.59%, media 73.9 ± 16.8%; post­quirúrgico 42.86-120.79%, media de 69.7 ± 16.5. Diferencia estadísticamente significativa 0.064). Conclusiones: El sistema de ganchos sublaminares en abordaje posterior ofrece mejoría de la curva de la escoliosis idiopática del adolescente evaluada por método de Cobb, detiene el progreso del deterioro de la función pulmonar, con mejoría significativa para el volumen espiratorio forzado en un segundo.

Abstract: Introduction: Scoliosis is a spine deformity diagnosed using Cobb's method when the AP X-ray view shows an angulation greater than 10o. Scoliosis exceeding 50o results in restrictive pulmonary alterations. Surgical management improves the angulation and the pulmonary restrictive process. The pre- and post-operative pulmonary function values were compared using spirometry. Material and methods: 27 patients of both genders, ages 11-15 years, underwent corrective surgery using posterior instrumentation with sublaminar hooks, rods and posterolateral arthrodesis. Spirometry was done preoperatively and six months after the surgery. Patients without a postoperative spirometry and/or a postoperative episode of pulmonary infection were excluded. The pre- and postoperative Cobb index was calculated. Spirometry: lung function at forced vital capacity (FVC) and forced expiratory volume in one second (FEV1). Descriptive statistics, Student t test. Results: Females, 78%; males, 22%; 13.7 ± 1.22 years. Cobb method 40 - 110o, preoperative angle 64.48 ± 17.79o and postoperative angle 30.44 ± 10.90º. There were no 0o values. Lung function: preoperative FVC for the values of the scoliosis curve (p < 0.0001) and significant marginal FEV1 (p = 0. Baseline: 40.6-122.0%, mean: 76.3 ± 18.8%, postoperative: 40.75-112.6%, mean: 76.5 ± 16.8%. Preoperative FEV1: 39.8-111.59%, mean: 73.9 ± 16.8%, postoperative: 42.86-120.79%, mean: 69.7 ± 16.5. The difference was statistically significant, 0.064). Conclusions: The sublaminar hook system with a posterior approach provides improvement of the idiopathic scoliosis curve of adolescents assessed with the Cobb method. It stops the progression of lung function impairment, with a significant improvement in forced expiratory volume in one second.