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In this study, an innovative conductive hybrid biomaterial was synthetized using collagen (COL) and reduced graphene oxide (rGO) in order for it to be used as a wound dressing. The hydrogels were plasticized with glycerol and enzymatically cross-linked with horseradish peroxidase (HRP). A successful interaction among the components was demonstrated by FTIR, XRD, and XPS. It was demonstrated that increasing the rGO concentration led to higher conductivity and negative charge density values. Moreover, rGO also improved the stability of hydrogels, which was expressed by a reduction in the biodegradation rate. Furthermore, the hydrogel's stability against the enzymatic action of collagenase type I was also strengthened by both the enzymatic cross-linking and the polymerization of dopamine. However, their absorption capacity, reaching values of 215 g/g, indicates the high potential of the hydrogels to absorb fluids. The rise of these properties positively influenced the wound closure process, achieving an 84.5% in vitro closure rate after 48 h. These findings clearly demonstrate that these original composite biomaterials can be a viable choice for wound healing purposes.

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BACKGROUND: To the best of our knowledge, studies on the relationship between spectral energy distribution and the degree of perceived twang-like voices are still sparse. Through an auditory-perceptual test we aimed to explore the spectral features that may relate with the auditory-perception of twang-like voices. METHODS: Ten judges who were blind to the test's tasks and stimuli rated the amount of twang perceived on seventy-six audio samples. The stimuli consisted of twenty voices recorded from eight CCM singers who sustained the vowel [a:] in different pitches, with and without a twang-like voice. Also, forty filtered and sixteen synthesized-manipulated stimuli were included. RESULTS AND CONCLUSIONS: Based on the intra-rater reliability scores, four judges were identified as suitable to be included in the analyses. Results showed that the frequency of F1 and F2 correlated strongly with the auditory-perception of twang-like voices (0.90 and 0.74, respectively), whereas F3 showed a moderate negative correlation (-0.52). The frequency difference between F1 and F3 showed a strong negative correlation (-0.82). The mean energy between 1-2 kHz and 2-3 kHz correlated moderately (0.51 and 0.42, respectively). The frequency of F4 and F5, and the energy above 3 kHz showed weak correlations. Since the spectral changes under 2 kHz have been associated with the jaw, lips, and tongue adjustments (i.e. vowel articulation) and a higher vertical laryngeal position might affect the frequency of all formants (including F1 and F2), our results suggest that vowel articulation and the laryngeal height may be relevant when performing twang-like voices.

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Subglottal Impedance-Based Inverse Filtering (IBIF) allows for the continuous, non-invasive estimation of glottal airflow from a surface accelerometer placed over the anterior neck skin below the larynx. It has been shown to be advantageous for the ambulatory monitoring of vocal function, specifically in the use of high-order statistics to understand long-term vocal behavior. However, during long-term ambulatory recordings over several days, conditions may drift from the laboratory environment where the IBIF parameters were initially estimated due to sensor positioning, skin attachment, or temperature, among other factors. Observation uncertainties and model mismatch may result in significant deviations in the glottal airflow estimates; unfortunately, they are very difficult to quantify in ambulatory conditions due to a lack of a reference signal. To address this issue, we propose a Kalman filter implementation of the IBIF filter, which allows for both estimating the model uncertainty and adapting the airflow estimates to correct for signal deviations. One-way analysis of variance (ANOVA) results from laboratory experiments using the Rainbow Passage indicate an improvement using the modified Kalman filter on amplitude-based measures for phonotraumatic vocal hyperfunction (PVH) subjects compared to the standard IBIF; the latter showing a statistically difference (p-value = 0.02, F = 4.1) with respect to a reference glottal volume velocity signal estimated from a single notch filter used here as ground-truth in this work. In contrast, maximum flow declination rates from subjects with vocal phonotrauma exhibit a small but statistically difference between the ground-truth signal and the modified Kalman filter when using one-way ANOVA (p-value = 0.04, F = 3.3). Other measures did not have significant differences with either the modified Kalman filter or IBIF compared to ground-truth, with the exception of H1-H2, whose performance deteriorates for both methods. Overall, both methods (modified Kalman filter and IBIF) show similar glottal airflow measures, with the advantage of the modified Kalman filter to improve amplitude estimation. Moreover, Kalman filter deviations from the IBIF output airflow might suggest a better representation of some fine details in the ground-truth glottal airflow signal. Other applications may take more advantage from the adaptation offered by the modified Kalman filter implementation.

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PURPOSE: This exploratory study aims to investigate variations in voice production in the presence of background noise (Lombard effect) in individuals with nonphonotraumatic vocal hyperfunction (NPVH) and individuals with typical voices using acoustic, aerodynamic, and vocal fold vibratory measures of phonatory function. METHOD: Nineteen participants with NPVH and 19 participants with typical voices produced simple vocal tasks in three sequential background conditions: baseline (in quiet), Lombard (in noise), and recovery (5 min after removing the noise). The Lombard condition consisted of speech-shaped noise at 80 dB SPL through audiometric headphones. Acoustic measures from a microphone, glottal aerodynamic parameters estimated from the oral airflow measured with a circumferentially vented pneumotachograph mask, and vocal fold vibratory parameters from high-speed videoendoscopy were analyzed. RESULTS: During the Lombard condition, both groups exhibited a decrease in open quotient and increases in sound pressure level, peak-to-peak glottal airflow, maximum flow declination rate, and subglottal pressure. During the recovery condition, the acoustic and aerodynamic measures of individuals with typical voices returned to those of the baseline condition; however, recovery measures for individuals with NPVH did not return to baseline values. CONCLUSIONS: As expected, individuals with NPVH and participants with typical voices exhibited a Lombard effect in the presence of elevated background noise levels. During the recovery condition, individuals with NPVH did not return to their baseline state, pointing to a persistence of the Lombard effect after noise removal. This behavior could be related to disruptions in laryngeal motor control and may play a role in the etiology of NPVH. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.20415600.

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Mine wastes from the La Aurora mine in the state of Guanajuato were generated by the flotation process and placed in four tailing dumps on the local stream while the plant operated. Given that these wastes contain toxic elements, it is important to establish their impact on the quality of several surrounding natural sources of water that are considered potential drinking water supplies. This study identified four water source types, in which the contents of arsenic (As), mercury (Hg), and thallium (Tl) were exceeded, according to international guideline values for drinking water quality. The first type of aqueous sample corresponded to leachates produced by rainwater infiltration in tailings and water-mineral waste interactions. The second type corresponded to surface water along the Xichú and La Laja Streams, and the third and fourth types involved two groundwater well samples and spring samples, respectively. The Chiquito Stream was used as a reference area that had not been impacted by the mine wastes. The isotopic signatures associated with δ34Ssulfate and δ18Osulfate compositions from the El Ojo de Agua spring are similar to those of the Santa María River and are different from those of the mine waste leachates. This study shows evidence of the presence of As in the El Ojo de Agua spring, which results from dissolution of secondary mineral phases that were produced by alteration of the mine wastes, which then migrated along the Xichú Stream system until reaching the spring. These As-bearing fine particles are prone to dissolution when in contact with this water source. Principal component analysis revealed that the observed As, Tl, and Hg can be attributed to weathering of the mine wastes. However, the results suggest that a natural contribution of these elements could be associated with rainwater-igneous rock interactions.

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The ambulatory assessment of vocal function can be significantly enhanced by having access to physiologically based features that describe underlying pathophysiological mechanisms in individuals with voice disorders. This type of enhancement can improve methods for the prevention, diagnosis, and treatment of behaviorally based voice disorders. Unfortunately, the direct measurement of important vocal features such as subglottal pressure, vocal fold collision pressure, and laryngeal muscle activation is impractical in laboratory and ambulatory settings. In this study, we introduce a method to estimate these features during phonation from a neck-surface vibration signal through a framework that integrates a physiologically relevant model of voice production and machine learning tools. The signal from a neck-surface accelerometer is first processed using subglottal impedance-based inverse filtering to yield an estimate of the unsteady glottal airflow. Seven aerodynamic and acoustic features are extracted from the neck surface accelerometer and an optional microphone signal. A neural network architecture is selected to provide a mapping between the seven input features and subglottal pressure, vocal fold collision pressure, and cricothyroid and thyroarytenoid muscle activation. This non-linear mapping is trained solely with 13,000 Monte Carlo simulations of a voice production model that utilizes a symmetric triangular body-cover model of the vocal folds. The performance of the method was compared against laboratory data from synchronous recordings of oral airflow, intraoral pressure, microphone, and neck-surface vibration in 79 vocally healthy female participants uttering consecutive /pæ/ syllable strings at comfortable, loud, and soft levels. The mean absolute error and root-mean-square error for estimating the mean subglottal pressure were 191 Pa (1.95 cm H2O) and 243 Pa (2.48 cm H2O), respectively, which are comparable with previous studies but with the key advantage of not requiring subject-specific training and yielding more output measures. The validation of vocal fold collision pressure and laryngeal muscle activation was performed with synthetic values as reference. These initial results provide valuable insight for further vocal fold model refinement and constitute a proof of concept that the proposed machine learning method is a feasible option for providing physiologically relevant measures for laboratory and ambulatory assessment of vocal function.

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Cellular senescence generates a permanent cell cycle arrest, characterized by apoptosis resistance and a pro-inflammatory senescence-associated secretory phenotype (SASP). Physiologically, senescent cells promote tissue remodeling during development and after injury. However, when accumulated over a certain threshold as happens during aging or after cellular stress, senescent cells contribute to the functional decline of tissues, participating in the generation of several diseases. Cellular senescence is accompanied by increased mitochondrial metabolism. How mitochondrial function is regulated and what role it plays in senescent cell homeostasis is poorly understood. Mitochondria are functionally and physically coupled to the endoplasmic reticulum (ER), the major calcium (Ca2+) storage organelle in mammalian cells, through special domains known as mitochondria-ER contacts (MERCs). In this domain, the release of Ca2+ from the ER is mainly regulated by inositol 1,4,5-trisphosphate receptors (IP3Rs), a family of three Ca2+ release channels activated by a ligand (IP3). IP3R-mediated Ca2+ release is transferred to mitochondria through the mitochondrial Ca2+ uniporter (MCU), where it modulates the activity of several enzymes and transporters impacting its bioenergetic and biosynthetic function. Here, we review the possible connection between ER to mitochondria Ca2+ transfer and senescence. Understanding the pathways that contribute to senescence is essential to reveal new therapeutic targets that allow either delaying senescent cell accumulation or reduce senescent cell burden to alleviate multiple diseases.

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Phonotraumatic vocal hyperfunction (PVH) is associated with chronic misuse and/or abuse of voice that can result in lesions such as vocal fold nodules. The clinical aerodynamic assessment of vocal function has been recently shown to differentiate between patients with PVH and healthy controls to provide meaningful insight into pathophysiological mechanisms associated with these disorders. However, all current clinical assessment of PVH is incomplete because of its inability to objectively identify the type and extent of detrimental phonatory function that is associated with PVH during daily voice use. The current study sought to address this issue by incorporating, for the first time in a comprehensive ambulatory assessment, glottal airflow parameters estimated from a neck-mounted accelerometer and recorded to a smartphone-based voice monitor. We tested this approach on 48 patients with vocal fold nodules and 48 matched healthy-control subjects who each wore the voice monitor for a week. Seven glottal airflow features were estimated every 50 ms using an impedance-based inverse filtering scheme, and seven high-order summary statistics of each feature were computed every 5 minutes over voiced segments. Based on a univariate hypothesis testing, eight glottal airflow summary statistics were found to be statistically different between patient and healthy-control groups. L1-regularized logistic regression for a supervised classification task yielded a mean (standard deviation) area under the ROC curve of 0.82 (0.25) and an accuracy of 0.83 (0.14). These results outperform the state-of-the-art classification for the same classification task and provide a new avenue to improve the assessment and treatment of hyperfunctional voice disorders.

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Purpose: The purpose of this study was to determine the validity of preliminary reports showing that glottal aerodynamic measures can identify pathophysiological phonatory mechanisms for phonotraumatic and nonphonotraumatic vocal hyperfunction, which are each distinctly different from normal vocal function. Method: Glottal aerodynamic measures (estimates of subglottal air pressure, peak-to-peak airflow, maximum flow declination rate, and open quotient) were obtained noninvasively using a pneumotachograph mask with an intraoral pressure catheter in 16 women with organic vocal fold lesions, 16 women with muscle tension dysphonia, and 2 associated matched control groups with normal voices. Subjects produced /pae/ syllable strings from which glottal airflow was estimated using inverse filtering during /ae/ vowels, and subglottal pressure was estimated during /p/ closures. All measures were normalized for sound pressure level (SPL) and statistically tested for differences between patient and control groups. Results: All SPL-normalized measures were significantly lower in the phonotraumatic group as compared with measures in its control group. For the nonphonotraumatic group, only SPL-normalized subglottal pressure and open quotient were significantly lower than measures in its control group. Conclusions: Results of this study confirm previous hypotheses and preliminary results indicating that SPL-normalized estimates of glottal aerodynamic measures can be used to describe the different pathophysiological phonatory mechanisms associated with phonotraumatic and nonphonotraumatic vocal hyperfunction.

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El presente estudio determinó si existe diferencia en el nivel de equilibrio en alumnos (as) de 1º y 2º básico por tipo de establecimiento y por sexo. Para esto, la muestra estuvo constituida por 316 alumnos (as), de los cuales 145 son mujeres y 171 son hombres, y 110 alumnos (as) representan a establecimien-tos municipales y 206 alumnos (as) representan a establecimientos particulares subvencionados de la comuna de La Granja. Los resultados muestran que existen diferencias en el equilibrio estático donde se ven favorecidos los establecimientos municipales, y por sexo las mujeres presentan un mejor nivel de equilibrio estático que los hombres. En equilibrio dinámico los establecimientos municipales presentan ventajas sobre los particulares subvencionados, y por sexo los varones presentan una leve ventaja sobre las mujeres. Es pertinente realizar una nueva investigación para comprobar si mediante un plan de ejercicios mejorará el nivel de equilibrio estático y dinámico de los alumnos (as) de 1º y 2º básico por tipo de establecimiento y por sexo.

The present study determined whether there was a difference in the equilibrium level of 6 to 7 year old students, depending on their educational establishment and their sex. The sample was made up of 316 students, of which 145 are women, 171 are men, and 110 students represent municipal establishments and 206 students represent private/subsidized establishments in the commune of La Granja, Chile. Results show that there are differences between static equilibrium by type of educational establishment, where municipal establishments fared better; In terms of sex, females demonstrated to have a better level of static equilibrium than males. In dynamic equilibrium, municipal establishments showed an advantage over private/subsidized ones, and as for sex, males fared slightly better than females. It is pertinent to carry out new research in order to verify if using an exercise plan actually improves the level of static and dynamic equilibrium in 6 to 7 year olds, depending on their educational establishment and sex.

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La miocarditis es la inflamación del corazón de etiología múltiple, es una enfermedad insidiosa, usualmente asintomática y es una causa importante de muerte repentina en adultos jóvenes. En Sudamérica la enfermedad de Chagas es la causa principal de miocarditis, y conlleva a la cardiomiopatía dilatada que es considerada como un síndrome clínico y fisiopatológico caracterizada por disfunción del miocardio, de la conducción eléctrica y dilatación de las cavidades del corazón, que predispone a la insuficiencia cardiaca y al desencadenamiento de muerte súbita. El diagnóstico de la miocarditis es dificultoso, a veces la clínica no nos aporta suficiente información y los exámenes complementarios específicos son invasivos, por eso debemos resaltar el uso de los métodos nucleares en el diagnóstico. La Gammagrafía cardiaca es un estudio radio isotópico del corazón con pirofosfato Tecnecio 99m o Galio 67, ambos se distribuyen específicamente por el tejido cardiaco inflamado.

Myocarditis is inflammation of the heart of multiple etiologies, is an insidious disease, usually asymptomatic and is a major cause of sudden death in young adults. In South America, Chagas disease is the leading cause of myocarditis and entails dilated cardiomyopathy which is considered as a clinical and pathophysiologic syndrome, characterized by myocardial dysfunction, of the myocardial electrical conduction and dilation of the heart chambers, which predisposes triggering heart failure and sudden death. The diagnosis of myocarditis is difficult, sometimes the clinic does not give us enough information and specific supplementary tests are invasive, so we highlight the use of nuclear methods in diagnosis. The heart scan is a heart radioisotope study with technetium pyrophosphate 99 m or Gallium 67; both are distributed specifically by inflamed heart tissue.

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The aim of this study was to evaluate the chemical composition, mold count and mycotoxin contamination of corn silage collected during a six month-period. The results indicated that the chemical composition and the physicochemical parameters evaluated did not show significant variation during the sampling time. Fungal count on RBC ranged from 1.7 x 10(3) to 9 x 10e8 CFU/g. Mucor, Penicillium and Aspergillus spp. were the most frequent fungal species in the corn silage. Fusarium count ranged from 1.6 x 10(3) to 1.6 x 10e8 CFU/g in Nash Snyder culture media. Aflatoxin B, fumonisins, ochratoxin A, ochratoxin B, deoxynivalenol, and zearalenone were detected throughout the period of corn silage maintenance (100% positive samples). However, only deoxynivalenol levels were higher than the maximum limit recommended by the FDA.

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La tuberculosis mamaria no es un diagnóstico usual debido a su baja incidencia. Puede ser primaria o, más frecuentemente, secundaria a diseminación linfática o hematógena de un foco pulmonar o por contiguidad. Se describe el caso de una paciente femenina de 22 años de edad, quien presentó signos de flogosis, con aparición posterior de lesiones y fistulización en ambas mamas. Se realizaron cultivos de secreción ecosonograma mamario, examen directo (KOH-10 por ciento), biopsia del tejido mamario y coloración de Ziehl-Nielsen (positiva); recibió tratamiento antituberculoso, con evolución satisfactoria. La tuberculosis mamaria es una rara condición que debe ser considerada como diagnóstico diferencial de tumoraciones y procesos inflamatorios mamarios en mujeres y hombres en países con una alta incidencia de infección por VIH y de tuberculosis

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Antecedentes. La epidemiología de la resistencia antimicrobiana en el ambiente hospitalario ha sido motivo de innumerables publicaciones, sin embargo, con respecto a microorganismos de origen comunitario la información es menos abundante. Objetivo. Precisar la frecuencia con que Escherichia Coli resulta no susceptible a los 14 antimicrobianos habitualmente empleados, en urocultivos practicados a población comunitaria. Material y métodos. Con el método de Kirby Bauer estandarizado por NCCLS, se evaluó la susceptibilidad a 14 antibióticos en un total de 404 cepas de Eschirichia coli procedentes de urocultivos con cuentas mayores a 100,000 UFC/mL. De éstas, 71 por ciento se aislaron en el laboratorio del Hospital General de Zona número 11 del IMSS (HGZ II) y 20 por ciento en el departamento de microbiología de Laboratorios Rivas S. de R.L. de C. V. (LRI). Resultados. Se demostró que en promedio existe resistencia a 24.7 por ciento de los antimicrobianos; ser más evidente en el medio hospitalario que en la comunidad (Delta + 6.2); con influencia de la edad del paciente (R=0.99) y que afecta de manera diferente y específica en cada uno de los antimicrobianos. Conclusión. La resistencia antimicrobiana de Eschirichia Coli uropatógena es un problema clínico significativo. Es conveniente que en nuestro país se haga un esfuerzo por regular el uso de antibióticos dentro y fuera de los hospitales

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La atresia esofágica es una de la malformaciones congenitas más importantes del tubo digestivo tanto por su frecuencia como por sus implicaciones fisiopatológicas en especial cuando existe cardiopatia congénita concomitante. En el presente trabajo se estudian 49 recién nacidos de los 2390 ingresos al Servicio de Neonatología del Hospital de Niños Baca Ortiz de Quito-Ecuador desde Enero de 1989 a mayo de 1996. de los cuales 26 fueron mujeres (53 por ciento) y 23 hombres (46.9 por ciento), 36 recien nacidos a término peso adecuado para edad gestacional (73 por ciento), 10 con bajo peso (20,5 por ciento) y 3 pretérmino (6.1 por ciento). Cuarenta y dos (85.9 por ciento) corresponden a atresia esofágica tipo III de Gros. Cardiopatía congénita se encontró en 15 casos (30 por ciento), El ductus arterioso permeable aislado fue el más frecuente en 6 casos(12,2 por ciento) acompañado de coartación de aorta estuvo en 3(6.1 por ciento), comunicación interauricular en 3(6.1 por ciento), tetralogia de fallot en 4 por ciento, uno (2.04 por ciento) presentó atresia tricúspidea tipo I A. La cardiopatía congénita como causa de muerte fue considerada en 3 pacientes. Se plantea la utilidad de la evaluación cardiológica en todo paciente portador de atresia Esofágica.

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El esfuerzo de un nn número cada vez mayor de científicos que trabajan en el campo de la inmunología, les ha permitido entregar a la práctica clínica, dos generaciones de inmunoglobulina parenteral: la normal y la específica, ambas de aplicación intramuscular (IM) y la ultima, la gamaglobulina de uso intravenoso (IV). Este trabajo pretende dos objetivos, el uno, es hacer una revisión actualizada de sus usos, pasando por un breve camino de la evaluación investigativa de la inmunología, hasta llegar a la obtención y actual aplicación de la segunda generación de la inmunoglobulina, la de uso intravenoso. El segundo objetivo, es introducirnos en el tema como anticipo a un estudio de la aplicabilidad de esta terapia en Servicios como el de Neonatología del Hospital de Niños "Baca Ortiz"

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El presente estudio trata sobre la morbi-mortalidad neonatal en pacientes atendidos en el Servicio de Neonatología, del Hospital de Niños Baca Ortíz (H.B.O)duarante enero a diciembre de 1991. Fueron atendidos 230 pacientes, con un promedio de 3.13 patologías por paciente. El presente trabajo revela que los casos de patología clínica corresonden a un 60.87 por ciento, mientras que los casos de patología quirúrgica fueron el 39.13 por ciento. La morbilidad clínica más frecuente fue la bronconeumonía y la quirúrgica el mielominingocele. Fallecieron 32 pacientes. La mortalidad general fue 13.9 por ciento de los pacientes clínicos el 10 por ciento y de los quirúrgicos el 20 por ciento. La principal causa de mortalidad fue por patología respiratoria y sepsis para los pacientes clínicos y malformaciones digestivos para los pacientes quirúrgicos...

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Se investigó el brote epidémico de infección por estafilococo coagulasa negativo en el servicio de Neonatología del Hospital Baca Ortíz de 1996 a 1997, de 295 pacientes ingresados 80 (27,12 por ciento) tuvieron hemocultivos positivos y de éstos únicamente 24 (8,13 por ciento) tuvieron 2 o más hemocultivos positivos y sintomatología, por lo que se considera a éstos como séptivos y a los 56 (18,98 por ciento) pacientes que tuvieron solamente bacteremia y/o contaminación por falta en la técnica de obtención del hemocultivo. El estafilococo coagulasa negativo presenta una alta resistencia a la penicilina, ampicilina, amoxicilina solas y sulfas-trimetropin que va de un 75 a 100 por ciento; un 52,5 por ciento de resistencia a la oxacilina...

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