A solar evaporator fabricated from corncob waste for the desalination of seawater and removal of oil/herbicides from contaminated water.

Corncob (CC) based solar evaporators were employed to desalinize seawater brought from the Vallarta coast in Mexico. The pure CC produced an evaporation-rate and evaporation-efficiency of 0.63 kg m-2 h-1 and 38.4%, respectively, under natural solar light. Later, the CC was coated with carbonized CC (CCCE evaporator) or was coated with graphene (CCGE evaporator). Those evaporators were used for the desalination of seawater and obtained higher evaporation rates of 1.59-1.67 kg m-2 h-1, and higher evaporation efficiencies of 92-94% (under natural solar light). The desalination experiments were repeated under artificial solar light and the evaporation-rates/evaporation-efficiencies slightly decreased to 1.43-1.52 kg m-2 h-1/88-92%. The surface analysis of the evaporators by FTIR, XPS and Raman revealed that the CCGE evaporator had on its surface a lower content of defects and a higher amount of OH groups than the CCCE evaporator. Therefore, the CCGE evaporator had higher evaporation-rates/evaporation-efficiencies in comparison with the CCCE evaporator. Furthermore, we purified water contaminated with three different herbicides (fomesafen, 2-6 dichlorobenzamide and 4-chlorophenol at 30 ppm) by evaporation and using natural solar light. Interestingly, the CCCE and CCGE evaporators also removed the herbicides by physical adsorption with efficiencies of 12-22.5%. Moreover, the CCGE evaporator removed vegetable oil from contaminated water by adsorption and its maximum adsorption capacity was 1.72 g/g. Overall, our results demonstrated that the corncob-based evaporators studied here are a low-cost alternative to obtain clean water under natural solar light and this one was more effective for the desalination of seawater than the artificial sunlight (Xe lamp).

Using NIR irradiation and magnetic bismuth ferrite microparticles to accelerate the removal of polystyrene microparticles from the drinking water.

Magnetic bismuth ferrite (BiFO) microparticles were employed for the first time for the removal of polystyrene (PS) nano/microplastics from the drinking water. BiFO is formed by porous agglomerates with sizes of 5-11 µm, while the PS nano/microparticles have sizes in the range of 70-11000 nm. X-ray diffraction studies demonstrated that the BiFO microparticles are composed of BiFeO3/Bi25FeO40 (the content of Bi25FeO40 is ≈ 8.6%). Drinking water was contaminated with PS nano/microparticles (1 g L-1) and BiFO microparticles were also added to the contaminated water. Later, the mixture of PS-particles + BiFO was irradiated with NIR light (980 nm). Consequently, PS nano/microparticles melted on the BiFO microparticles due to the excessive heating on their surface. At the same time, the NIR (near infrared) light generated oxidizing agents (∙OH and h+), which degraded the by-products formed during the photocatalytic degradation of PS nano/microparticles. Subsequently, the NIR irradiation was stopped, and a Neodymium magnet was utilized to separate the BiFO microparticles from the water. This last procedure also permitted the removal of PS nano/microparticles by physical adsorption. Zeta potential measurements demonstrated that the BiFO surface was positively charged, allowing the removal of the negatively charged PS nano/microparticles by electrostatic attraction. The combination of the photocatalytic process and the physical adsorption permitted a complete removal of PS nano/microparticles after only 90 min as well as a high mineralization of by-products (≈95.5% as confirmed by the total organic carbon measurements). We estimate that ≈23.6% of the PS nano/microparticles were eliminated by photocatalysis and the rest of PS particles (≈76.4%) by physical adsorption. An outstanding adsorption capacity of 195.5 mg g-1 was obtained after the magnetic separation of the BiFO microparticles from the water. Hence, the results of this research demonstrated that using photocatalysis + physical-adsorption is a feasible strategy to quickly remove microplastic contaminants from the water.

Tumores de parótida en población pediátrica: 10 años de experiencia / PAROTID TUMORS IN PEDIATRIC POPULATION: 10 YEARS OF EXPERIENCE

Introducción: Los tumores de las glándulas salivales son infrecuentes en la población en general y comprenden menos del 3% de los tumores de cabeza y cuello1 . En pediatría el 90% corresponden a tumores de la glándula parótida,2 siendo en su mayoría tumores benignos. Objetivo: Describir la incidencia de tumores parotídeos en un centro de referencia, haciendo hincapié en la variabilidad etiológica y la presentación por grupos etarios. Materiales y métodos: Se trata de un estudio de cohorte retrospectivo de pacientes menores de 18 años con tumores de parótida en un periodo de 10 años: de 2011 a 2021, seguidos en el Servicio de Cirugía General Pediátrica del Hospital Italiano de Buenos Aires. Se incluyeron todos los pacientes pediátricos que presentaron tumor en la región parotídea seguidos o tratados en este centro, se excluyeron aquellos que no se pudieron recabar los datos de forma completa. Las variables analizadas fueron edad, sexo, forma de presentación, estudios complementarios, tipo de tratamiento, histología, complicaciones. Resultados: Se analizaron un total de 33 pacientes, de estos un 64% (N = 21) fueron mujeres, con una relación mujer/hombre de 1,7. La media de edad al diagnóstico fue de 8.5 años, siendo 2 de diagnóstico prenatal y hasta los 18 años. La localización fue en un 57% (N = 19) izquierda, el 43% restante derecha. La forma de presentación más frecuente fue la masa palpable en región parotídea 75% (N=25), en dos pacientes fue un hallazgo en estudios por imágenes: resonancia prenatal y otro por resonancia de cerebro. Conclusiones: en pediatría, a diferencia de la población adulta, se presentan una gran variedad de diagnósticos, que incluye desde lesiones vasculares hasta tumores malignos. Debido a que las lesiones parotídeas malignas son clínicamente indistinguibles de las benignas, es importante establecer un diagnóstico preciso. Esta serie representa esta diversidad etiológica en pediatría, así como la distribución etaria comparada con la descrita por la literatura

Introduction: Salivary gland tumors are rare in the general population and comprise less than 3% of head and neck tumors1. In pediatrics, 90% correspond to tumors of the parotid gland,2 being mostly benign tumors. Objective: To describe the incidence of parotid tumors in a reference center, emphasizing the etiological variability and the presentation by age groups. Materials and methods: Tis is a retrospective cohort study of patients under 18 years of age with parotid tumors over a period of 10 years: from 2011 to 2021, followed up at the Pediatric General Surgery Service of the Italian Hospital of Buenos Aires. All pediatric patients who presented tumor in the parotid region followed up or treated in this center were included, those who could not collect the data completely were excluded. Te variables analyzed were age, sex, form of presentation, complementary studies, type of treatment, histology, and complications. Results: A total of 33 patients were analyzed, of which 64% (N = 21) were women, with a female/male ratio of 1.7. Te mean age at diagnosis was 8.5 years, with 2 prenatal diagnoses and up to 18 years. Te location was 57% (N = 19) left, the remaining 43% right. Te most frequent form of presentation was a palpable mass in the parotid region 75% (N=25), in two patients it was a finding in imaging studies: prenatal MRI and another by brain MRI. Conclusions: in pediatrics, unlike the adult population, a wide variety of diagnoses are presented, ranging from vascular lesions to malignant tumors. Because malignant parotid lesions are clinically indistinguishable from benign ones, it is important to establish an accurate diagnosis. Tis series represents this etiological diversity in pediatrics, as well as the age distribution compared to that described in the literature

Usefulness of combined ultrasonography and scintigraphy in the preoperative assessment of secondary or tertiary hyperparathyroidism. / Utilidad de la combinación de ecografía y gammagrafía en evaluación preoperatoria de hiperparatiroidismo secundario o terciario.

OBJECTIVE: To determine whether combined ultrasonography and parathyroid scintigraphy improves hyperplastic parathyroid gland detection in the pediatric population for parathyroidectomy planning in patients with secondary or tertiary hyperparathyroidism. MATERIAL AND METHODS: An observational and analytical retrospective cohort study was carried out. Patients diagnosed with secondary or tertiary hyperparathyroidism from 2011 to 2018 undergoing total or subtotal parathyroidectomy were included - provided there was information available on pathological examination and surgical protocol. RESULTS: N = 15 patients. A total of 53 parathyroid glands diagnosed with hyperplasia using either of the imaging methods were analyzed. For each method (ultrasonography and scintigraphy) and the combination of both, sensitivity and area under the curve were calculated, using pathological examination result as a reference. Ultrasonography and scintigraphy diagnostic match was 66%. DISCUSSION AND CONCLUSIONS: The intraoperative difficulty of parathyroid gland identification as well as the anatomical variation that these present is well-known. Ultrasonography detected more glands than scintigraphy when diagnosing parathyroid hyperplasia. The combination of both methods allows patients with a first negative study to be detected.

OBJETIVO: Determinar si la combinación de la ecografía y la gammagrafia paratiroidea mejora la capacidad de detección de glándulas paratiroideas hiperplásicas en población pediátrica para la planificación de paratiroidectomía en pacientes con hiperparatiroidismo secundario o terciario. MATERIAL Y METODOS: Estudio observacional y analítico de una cohorte retrospectiva. Se incluyeron pacientes con hiperparatiroidismo secundario o terciario, entre 2011 y 2018, que fueron operados de paratiroidectomía total o subtotal, en los que haya podido recabarse información de la anatomía patológica y protocolo quirúrgico. RESULTADOS: N = 15 pacientes. Se analizaron un total de 53 glándulas paratiroides con diagnóstico de hiperplasia en alguno de los métodos por imágenes evaluados. Para cada método (ecografía y gammagrafía) y para la combinación de ambos, se obtuvieron la sensibilidad y área bajo la curva, tomando como referencia el resultado obtenido por anatomía patológica. La concordancia en el diagnóstico de la ecografía y de la gammagrafía fue del 66%. DISCUSION Y CONCLUSIONES: Es bien conocida la dificultad intraquirúrgica que se plantea en cuanto a la localización de las glándulas paratiroides así como la variación anatómica que estas presentan. La ecografía detectó más glándulas que la gammagrafía en el diagnóstico de hiperplasia paratiroidea. La combinación de ambos métodos permite detectar a aquellos pacientes en los cuales un primer estudio resultó negativo.

Morphological and Mechanical Properties of Electrospun Polycaprolactone Scaffolds: Effect of Applied Voltage.

The aim of this work is to investigate the effect of the applied voltage on the morphological and mechanical properties of electrospun polycaprolactone (PCL) scaffolds for potential use in tissue engineering. The morphology of the scaffolds was characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), and the BET techniques for measuring the surface area and pore volume. Stress-strain curves from tensile tests were obtained for estimating the mechanical properties. Additional studies for detecting changes in the chemical structure of the electrospun PCL scaffolds by Fourier transform infrared were performed, while contact angle and X-ray diffraction analysis were realized for determining the wettability and crystallinity, respectively. The SEM, AFM and BET results demonstrate that the electrospun PCL fibers exhibit morphological changes with the applied voltage. By increasing the applied voltage (10 to 25 kV) a significate influence was observed on the fiber diameter, surface roughness, and pore volume. In addition, tensile strength, elongation, and elastic modulus increase with the applied voltage, the crystalline structure of the fibers remains constant, and the surface area and wetting of the scaffolds diminish. The morphological and mechanical properties show a clear correlation with the applied voltage and can be of great relevance for tissue engineering.

Neurobiology of anesthetic-surgical stress and induced behavioral changes in dogs and cats: A review.

The anesthetic-surgical stress response consists of metabolic, neuroendocrine, hemodynamic, immunological, and behavioral adaptations through chemical mediators such as the adrenocorticotropic hormone, growth hormone, antidiuretic hormone, cortisol, aldosterone, angiotensin II, thyroid-stimulating hormone, thyroxine, triiodothyronine, follicle-stimulating hormone, luteinizing hormone, catecholamines, insulin, interleukin (IL)-1, IL-6, tumor necrosis factor-alpha, and prostaglandin E-2. Behavioral changes include adopting the so-called prayer posture, altered facial expressions, hyporexia or anorexia, drowsiness, sleep disorders, restriction of movement, licking or biting the injured area, and vocalizations. Overall, these changes are essential mechanisms to counteract harmful stimuli. However, if uncontrolled surgical stress persists, recovery time may be prolonged, along with increased susceptibility to infections in the post-operative period. This review discusses the neurobiology and most relevant organic responses to pain and anesthetic-surgical stress in dogs and cats. It highlights the role of stress biomarkers and their influence on autonomous and demeanor aspects and emphasizes the importance of understanding and correlating all factors to provide a more accurate assessment of pain and animal welfare in dogs and cats throughout the surgical process.

Autopercepción de capacidades de autocuidado para prevención de enfermedades crónicas no transmisibles en estudiantes universitarios / Self-perception on self-care capacity in preventing noncommunicable chronic diseases among university students / Autopercepção de capacidades de autocuidado para prevenção de doenças crónicas não transmissíveis em estudantes universitários

Introducción: La incidencia de enfermedades crónicas no transmisibles (ECNT), va en aumento entre la población más joven. La autopercepción de capacidades de autocuidado (CAC), es un punto de partida para el desarrollo de habilidades y destrezas para el propio cuidado. Objetivo: Identificar el nivel de autopercepción de CAC para la prevención de enfermedades crónicas no transmisibles en estudiantes universitarios de nuevo ingreso, para establecer estrategias que permitan un mejor conocimiento de su salud. Métodos: Estudio cuantitativo, descriptivo, transversal y analítico. Muestra aleatorizada, obtenida por cálculo de poblaciones finitas. Se aplicó el Instrumento para identificar las capacidades de autocuidado en enfermedades crónico-degenerativas, salud sexual-reproductiva y prevención de adicciones; análisis descriptivo y analítico, con pruebas paramétricas y no paramétricas. Resultados: La autopercepción de CAC fue muy buena en un 8%, buena en 54%, regular en 36% y mala en 2%. Las diferencias entre áreas de conocimiento y el nivel de autopercepción fueron significativas (p=0.025). La licenciatura en medicina tuvo mejor puntaje de autocuidado ( x -=27.51). Discusión: Los principales resultados encontrados coinciden con diversos estudios que evalúan la dimensión de autopercepción. Existen claras divergencias entre el autocuidado percibido y el realizado, lo que hace evidente la necesidad de desarrollo de CAC. Conclusiones: Es necesario promover estilos saludables para mitigar efectos, costos e implicaciones sociales. Se puede incidir desde la consultoría de enfermería, para favorecer el desarrollo de capacidades de autocuidado en estudiantes universitarios.

Introduction: The incidence of non-communicable chronic diseases among younger populations is on the rise. Self-perception of self-care capacity is a beginning point to develop abilities and skills to address the own care. Objective: To identify the level of self-perception of self-capacity to prevent non-communicable chronic diseases among newly enrolled university students in order to establish strategies which convey a better understanding of this population's health. Methods: This is a quantitative, descriptive, transversal, and analytic study which used a random sample gathered by finite populations calculation. The Identification instrument on the capacity of self-care regarding chronic-degenerative diseases, sexual-reproductive health, and addiction prevention was administered. A descriptive and analytic analysis calculating parametric and non-parametric tests was carried out. Results: Self-perception on self-capacity showed to be very good in 8% of the sample, good in 54%, fair in 36%, and poor in 2%. The differences between the knowledge level and the self-perception level were significant (p=0.025). Students enrolled in Medicine had the highest mean score. Discussion: The main results of this study reflect agreement with other studies assessing the dimension of self-perception; nevertheless, a clear gap between perceived self-care and performed self-care, still remains. Conclusions: It is necessary to promote healthy lifestyles among university students in order to enhance their health self-perception and consequent self-care.

Introdução: A incidência de doenças crónicas não transmissíveis (ECNT), vai em aumento entre a população mais jovem. A autopercepção de capacidades de autocuidado (CAC), é um ponto de partida para o desenvolvimento de habilidades e destrezas para o cuidado próprio. Objetivo: Identificar o nível de autopercepção de CAC para a prevenção de doenças crónicas não transmissíveis em estudantes universitários de ingresso novo, para estabelecer estratégias que permitam um melhor conhecimento de sua saúde. Métodos: Estudo quantitativo, descritivo, transversal e analítico. Amostra aleatorizada, obtida por cálculo de populações finitas. Aplicou-se o Instrumento para identificar as capacidades de autocuidado em doenças crônico-degenerativas, saúde sexual-reprodutiva e prevenção de dependência; análise descritiva e analítica, com probas paramétricas e não paramétricas. Resultados: A autopercepção de CAC foi muito boa em um 8%, boa em 54%, regular em 36% e precária em 2%. As diferenças entre áreas de conhecimento e o nível de autopercepção foram significativas (p=0.025). A licenciatura em medicina teve melhor pontuação de autocuidado ( x -=27.51). Discussão: Os principais resultados encontrados coincidem com diversos estudos que avaliam a dimensão de autopercepção. Existem divergências manifestas entre o autocuidado percebido e o realizado, o que faz evidente a necessidade de desenvolvimento de CAC. Conclusões: É necessário promover estilos saudáveis para mitigar consequências, custos e implicações sociais. Pode influir desde a consultoria de enfermagem, para favorecer o desenvolvimento de capacidades de autocuidado em estudantes universitários.

Physicochemical characterization of several types of naturally colored cotton fibers from Peru.

Elemental composition, physical dimensions (length and apparent diameter), and crystallinity of different types of naturally colored cotton (NCCs) fibers from Peru were investigated using a CHNS organic elemental analyzer, optical microscopy and X-Ray Diffraction (XRD). Spectroscopic studies involving Fourier Transform Infrared Spectroscopy and X-Ray photoelectron spectroscopy (XPS) were conducted; and the thermal stability of cotton samples were also investigated. Results from organic elemental analyzer and XPS showed that cotton samples contain mainly carbon, oxygen and hydrogen, but darker color samples also presented nitrogen. It was also found that the white cotton sample exhibited the longest fibers whereas the darker color samples showed the shortest values in length. Interestingly, the crystallinity seems also decrease with color intensity of NCCs. Finally, the thermal stability of white cotton fibers was similar to those obtained for the NCCs.

Displasias esqueléticas: Reporte de un caso y revisión de la literatura / Skeletal dysplasias: Report of a case and review of the literature

RESUMEN Las displasias esqueléticas son un grupo heterogéneo de condiciones que afectan primariamente la formación y crecimiento de huesos y cartílagos, se caracterizan por un acortamiento generalizado de huesos largos. Son patologías de baja prevalencia, que se pueden diagnosticar con precisión mediante ultrasonografía del primer y segundo trimestre. La importancia de esta patología radica en que posee una letalidad cercana al 50%. La displasia esqueletica letal más frecuente es la displasia tanatofórica, la cual se caracteriza por macrocefalia con base de cráneo estrecha, tórax estrecho, cuerpos vertebrales planos, micromelia generalizada, ausencia de fracturas, ventriculomegalia, polihidroamnios y mineralización ósea normal. Debido a que la presentación de la displasia tanatoforica se debe a una mutación autosómica dominante de novo no germinal, el riesgo de recurrencia no es mayor que el de la población general. Dado su elevada letalidad no pasa a generaciones futuras.

SUMMARY Skeletal dysplasias are a heterogeneous group of conditions that primarily affect the formation and growth of bones and cartilage, characterized by a generalized shortening of long bones. These are pathologies of low prevalence, which can be accurately diagnosed by first and second trimester ultrasonography. The importance of this pathology lies in that it has a lethality close to 50%. The most common lethal skeletal dysplasia is tanophilic dysplasia, which is characterized by macrocephaly with a narrow cranial base, narrow chest, flat vertebral bodies, generalized micromelia, absence of fractures, ventriculomegaly, polyhydroamnios and normal bone mineralization. Because the presentation of the tanophoretic dysplasia is due to an autosomal dominant mutation of novo non-germinal, the risk of recurrence is not greater than that of the general population. Given its high lethality does not happen to future generations.

Controversias en el tratamiento de la estrumosis peritoneal: caso clínico y revisión bibliográfica / Controversies in the management of peritoneal strumosis: Case report and literature review

Resumen ANTECEDENTES: el estruma ovárico es un teratoma monodérmico, sumamente complejo, constituido en más de 50% por tejido tiroideo. Una forma infrecuente de manifestación es la estrumosis peritoneal, que consiste en múltiples implantes peritoneales benignos compuestos por estruma ovárico. No existe consenso en relación con el tratamiento; además, la malignidad de la estrumosis peritoneal es tema de controversia. CASO CLÍNICO: paciente nuligesta de 33 años de edad a quien, durante el estudio de esterilidad primaria, se le diagnosticó estruma ovárico derecho. A los tres años postratamiento recurrió en forma de estruma ovárico izquierdo y estrumosis peritoneal (hallazgo intraoperatorio). En ambos casos se efectuó quistectomía laparoscópica, y en la segunda ocasión se practicó, además, la exéresis de los implantes macroscópicos. Después de recibir quimioterapia con 131I (100 mCi) y entrar en remisión completa, se produjo una nueva recidiva cuatro años después; fue necesaria la cirugía citorreductora y un nuevo ciclo de quimioterapia con 131I (100 mCi). En la actualidad la paciente permanece en remisión completa. CONCLUSIONES: ante la escasez de casuística de estrumas ováricos y, sobre todo, de estrumosis peritoneal, resulta imprescindible individualizar el tratamiento en cada paciente, en donde es decisiva la participación de un equipo multidisciplinario. La cirugía citorreductora puede ser una opción terapéutica para favorecer la respuesta al tratamiento ablativo con 131I.

Abstract BACKGROUND: Struma ovarii is a highly specialized monodermic teratoma composed of thyroid tissue in more than 50%. An infrequent form of presentation is peritoneal strumosis, which consists of multiple peritoneal implants of benign mature thyroid tissue. In both situations, there is no consensus about the management of those entities. In addition, malignancy of peritoneal strumosis is controversial. CLINICAL CASE: We report a case of a 33-year-old nulligravid woman that during a sterility study was diagnosed with a right struma ovarii. Three years after treatment, it recurred as a left struma ovarii and a peritoneal strumosis (intraoperative finding). A laparoscopic ovarian cystectomy was performed in both cases, as well as the excision of all macroscopic implants in the second one. She remained in remission after 131I ablative chemotherapy (100 mCi), but a new recurrence took place four years later, requiring a cytoreductive surgery and a second 131I chemotherapy (100 mCi). She is now in complete remission. CONCLUSIONS: Due to the lack of casuistry of struma ovarii and paucity of information, especially in the case of peritoneal strumosis, decisions must be individualized on each patient and must be taken by a multidisciplinary team. Cytoreductive surgery might be an option to improve the response to ablative 131I chemotherapy.

Diástasis de la sínfisis púbica posparto / Postpartum pubic symphysis diastasis

Resumen ANTECEDENTES: ante un dolor pélvico intenso en una paciente embarazada, durante el parto o puerperio inmediato, debe considerarse la posibilidad de diástasis de la sínfisis del pubis, que es una afección poco frecuente e infradiagnosticada que puede resultar muy dolorosa e invalidante porque daña considerablemente la calidad de vida. A la exploración física se advierte: dolor intenso en la sínfisis púbica, que puede irradiarse hacia la zona lumbar o ambos muslos. Para establecer el diagnóstico definitivo es necesaria una prueba de imagen que muestre una separación entre ambas ramas ≥ 10 mm. En función de la clínica y el grado de separación puede optarse por un tratamiento conservador o, bien, por una intervención quirúrgica con osteosíntesis y estabilización del anillo pélvico. CASO CLÍNICO: paciente que luego de un parto eutócico experimentó dolor pélvico intenso e incapacidad para la deambulación y sedestación. Con base en la imagen radiográfica antero-posterior de la pelvis se estableció el diagnóstico de diástasis severa de la sínfisis del pubis, con afectación de la articulación sacroiliaca. El tratamiento fue quirúrgico, con buena evolución posterior. CONCLUSIONES: las formas leves de esta afección son infradiagnosticadas. El retraso en el diagnóstico y tratamiento implica dolor residual y empeora el pronóstico de la enfermedad. Es importante tener en mente este diagnóstico a la hora del diagnóstico diferencial de dolor pélvico en una paciente embarazada o puérpera.

Abstract BACKGROUND: In the presence of severe pelvic pain in a pregnant patient, during childbirth or the immediate puerperium, it is necessary to consider the possibility of a diastasis of the pubic symphysis. It is a rare and underdiagnosed pathology that can be very painful and invalidating and seriously worsens the quality of life. Physical examination shows intense pain at the level of the pubic symphysis that can radiate towards the lower back or both thighs. Definitive diagnosis requires an image test showing a separation between the two pubic bones ≥10 mm. Depending on symptomatology and the degree of separation, it is possible a conservative treatment or surgery, with osteosynthesis and stabilization of the pelvic ring. CLINICAL CASE: Patient who experienced intense pelvic pain and incapacity for ambulation and sedation after a eutocic delivery for ambulation and sedestation. After an anteroposterior radiograph of the pelvis, a severe diastasis of the pubic symphysis was diagnosed with affectation of the sacroiliac joint and required surgical treatment with a favourable evolution. CONCLUSIONS: Mild forms of this condition are underdiagnosed. Delay in diagnosis and treatment involves residual pain and worsens the prognosis of the disease. It is important to keep this diagnosis in mind at the time of the differential diagnosis of pelvic pain in a pregnant or puerperal patient.

Acortamiento relativo de clavícula en fracturas pediátricas: Su importancia en la decisión del tratamiento conservador / Relative clavicle shortening in pediatric fractures: Its importance when selecting conservative treatment

Antecedentes: Las fracturas de clavícula representan de 2 a 15% de las fracturas pediátricas. La literatura sugiere operar pacientes mayores de 9 años con acortamiento mayor o severa conminución en el trazo de fractura, pero nadie establece parámetros de acortamiento o angulación para el tratamiento conservador en niños. En pacientes pediátricos es importante tomar en cuenta el acortamiento relativo, es decir, aquel provocado por una fractura, ajustado a la longitud sana. Objetivo: Conocer la afectación del movimiento con relación al acortamiento relativo de clavícula en fracturas pediátricas tratadas de forma conservadora. Material y métodos: Estudio retrospectivo, longitudinal y observacional. Medimos radiográficamente el acortamiento relativo de la clavícula fracturada comparándola con el lado sano al momento de la fractura y una vez consolidada. El acortamiento se expresó en porcentajes. Las proyecciones utilizadas fueron: anteroposterior comparativa de hombros y panorámica con ambos hombros. Los pacientes se dividieron en 2 grupos: menores de 9 años y de 9 a 15 años. Resultados: Analizamos 94 fracturas, 31 mujeres y 63 hombres. No se presentó seudoartrosis o consolidación viciosa sintomática. El pronóstico fue bueno sin importar el porcentaje de acortamiento inicial. La edad y el acortamiento tienen una relación proporcional al periodo de rehabilitación y restitución de los arcos de movilidad sin molestias. Los rangos de valores registrados para acortamiento fueron de 9.5 a 28%. Conclusiones: Las indicaciones quirúrgicas por acortamiento para fracturas de clavícula pediátrica deben revisarse. Hemos observado buenos resultados a pesar del acortamiento mayor y desplazamiento total.

Background: Clavicle fractures represent 2-15% of pediatric fractures. The literature suggests operating on patients over 9 years of age with major shortening or severe comminution in the fracture line. However, no one establishes shortening or angulation parameters for conservative treatment in children. In pediatric patients it is important to take into account relative shortening, that is, the one caused by a fracture when compared with the length of the healthy clavicle. Objective: To know the effect of relative clavicle shortening on movement in pediatric fractures treated conservatively. Material and methods: Retrospective, longitudinal, observational study. We radiographically measured the relative shortening of the fractured clavicle comparing it with the healthy side at the time of the fracture and after fracture healing. Shortening was expressed in percentages. The following views were used: comparative anteroposterior view of the shoulders and panoramic view of both shoulders. Patients were divided into 2 groups: under 9 years and 9-15 years of age. Results: We analyzed 94 fractures; 31 in females and 63 in males. No pseudoarthrosis or symptomatic malunion occurred. The prognosis was good regardless of the initial shortening percentage. Age and shortening are proportionally related with the rehabilitation period and the restoration of painless ranges of motion. The value ranges recorded for shortening were 9.5 to 28%. Conclusions: The surgical indications for shortening resulting from pediatric clavicle fractures should be revised. We have observed good results despite major shortening and total displacement.

[Relative clavicle shortening in pediatric fractures: its importance when selecting conservative treatment]. / Acortamiento relativo de clavícula en fracturas pediátricas: Su importancia en la decisión del tratamiento conservador.

BACKGROUND: Clavicle fractures represent 2-15% of pediatric fractures. The literature suggests operating on patients over 9 years of age with major shortening or severe comminution in the fracture line. However, no one establishes shortening or angulation parameters for conservative treatment in children. In pediatric patients it is important to take into account relative shortening, that is, the one caused by a fracture when compared with the length of the healthy clavicle. OBJECTIVE: To know the effect of relative clavicle shortening on movement in pediatric fractures treated conservatively. MATERIAL AND METHODS: Retrospective, longitudinal, observational study. We radiographically measured the relative shortening of the fractured clavicle comparing it with the healthy side at the time of the fracture and after fracture healing. Shortening was expressed in percentages. The following views were used: comparative anteroposterior view of the shoulders and panoramic view of both shoulders. Patients were divided into 2 groups: under 9 years and 9-15 years of age. RESULTS: We analyzed 94 fractures; 31 in females and 63 in males. No pseudoarthrosis or symptomatic malunion occurred. The prognosis was good regardless of the initial shortening percentage. Age and shortening are proportionally related with the rehabilitation period and the restoration of painless ranges of motion. The value ranges recorded for shortening were 9.5 to 28%. CONCLUSIONS: The surgical indications for shortening resulting from pediatric clavicle fractures should be revised. We have observed good results despite major shortening and total displacement.

Dynamics of carbon nanotube alignment by electric fields.

The dynamics of multiwall carbon nanotube (MWCNT) alignment inside viscous media using electric fields is investigated. Electrical current measurements were performed in situ during the application of an electric field to liquid solutions of deionized water or dissolved polymer containing MWCNTs. The variation of electrical current over time was associated to the dynamics of the MWCNT network formation. The influence of the electric field magnitude and frequency on the MWCNT network formation was studied. MWCNT migration towards the negative electrode was observed when a direct current electric field was applied, whereas formation of an aligned MWCNT network was achieved for an alternating current electric field. The increase of the electric field frequency promotes a faster formation of an aligned MWCNT network and thinner MWCNT bundles. A higher viscosity of the liquid medium yields slower MWCNT alignment evidenced by a slower change of electrical current through the viscous system. An analytical model based on the dielectrophoresis-induced torque, which considers the viscosity of the medium, is also proposed to explain the dynamics of MWCNT alignment. Furthermore, aligned MWCNT/polysulfone solid composites were fabricated and electrically characterized. The solid composites presented anisotropic electrical conductivity, which was more evident for low MWCNT concentrations (0.1-0.2 wt%).

[Otomyiasis by Cochliomyia hominivorax in two children from the outskirts of Buenos Aires, Argentina]. / Otomiasis por Cochliomyia hominivorax en dos niños del conurbano bonaerense, Argentina.

Cochliomyia hominivorax causes 80% of human myiasis in Argentina. Nowadays, its geographic distribution covers tropical South America and an important region of Argentina. In the present report, two clinical cases of otomyiasis by C. hominivorax in pediatric patients assisted at the Hospital de Clinicas of Buenos Aires, Argentina are described. The relevance of the taxonomic identification lies in the fact that this species produces severe symptoms owing to the capacity of its larvae to drill the bones and cause the host's death.

Feeding habits of four species of mesopelagic fishes from the Northern Chilean

The feeding habits of four species of mesopelagic fishes from northern Chile are described: Triphoturus mexicanus, Diogenichtys atlanticus, Vinciguerria lucetia and Cyclothone acclinidens. Samples were captured in September 1988 between 18 degrees 25' and 19 degrees 09'S in the South West Pacific. The quantitative and qualitative analyses of the stomach content showed that the species have a zooplanktophagous opportunistic behavior, mainly predating on Crustaceans, especially on Copepods. The evaluation of the trophic spectrum and diversity of T. mexicanus and C. acclinidens suggests that these are nictoepipelagic species, while D. atlanticus and V. lucetia would be typical mesopelagic.

Se describen los hábitos alimenticios de cuatro especies de peces mesopelágicos del norte de Chile: Triphoturus mexicanus, Diogenichtys atlanticus, Vinciguerria lucetia and Cyclothone acclinidens. Las muestras fueron capturadas en setiembre de 1988 entre 18°25’ y 19°09’ S en el Pacífico suroeste. El análisis cualitativo y cuantitativo del contenido estomacal mostró que las especies tienen un comportamiento zooplantofago oportunista, depredando principalmente crustáceos, especialmente copépodos. La evaluación del espectro trófico y diversidad de T. mexicanus y C. acclinidens sugiere que estas son especies nictoepipelágicas, mientras que D. alanticus y V. lucetia serían mesopelágicas típicas.

Feeding habits of four species of mesopelagic fishes from the Northern Chilean.

The feeding habits of four species of mesopelagic fishes from northern Chile are described: Triphoturus mexicanus, Diogenichtys atlanticus, Vinciguerria lucetia and Cyclothone acclinidens. Samples were captured in September 1988 between 18 degrees 25' and 19 degrees 09'S in the South West Pacific. The quantitative and qualitative analyses of the stomach content showed that the species have a zooplanktophagous opportunistic behavior, mainly predating on Crustaceans, especially on Copepods. The evaluation of the trophic spectrum and diversity of T. mexicanus and C. acclinidens suggests that these are nictoepipelagic species, while D. atlanticus and V. lucetia would be typical mesopelagic.

Seasonal patterns of arthropods occurring on sheltered and unsheltered pig carcasses in Buenos Aires Province (Argentina).

Differences in the succession of insects and other Arthropoda (invertebrate animals with jointed legs), on domestic pig carcasses placed under a roof and under the open sky have been studied in Buenos Aires Province, Argentina (latitude 34 degrees 45'S) in all the seasons of the year. Faunal associations proved different for each treatment in winter: the common bluebottle Calliphora vicina was found in both, but on the sheltered carcass Cochliomyia macellaria and the rare Phaenicia cluvia were found as well. In the fall, the difference between sheltered and unsheltered carcasses was small (six species on the former and five species on the latter); in spring and summer, the difference was negligible.

Insects of forensic significance in Argentina.

Records from forensic expertises and trappings with beef baits conducted in Buenos Aires, Argentina (34 degrees 36'S), show that the dominating species are widespread ones (Calliphora vicina and Phaenicia sericata), with different behaviour in each large latitudinal zone. It is suggested that the range of the yearly photoperiod variation has an influence in the behaviour of the blowflies, making up for differences in the succession patterns. The Calliphorid blowflies Cochliomyia macellaria and Chysomya albiceps were found on indoors corpses; the latter also on outdoors corpses when blood was shed, and in that case as primary. Three species of beetles of the genus Dermestes, which had been associated with mummified remains, appeared 10-30 days after death. The Silphid beetle Hyponecrodes sp. cf. erythrura was found on outdoor copses in rural environments. The Nitidulid beetle Carpophilus hemipterus was found in association with the cheese skipper Piophila sp. (Diptera: Piophilidae) in medullar cavities of bones after ca. 30 days; to this association is often added the Clerid Necrobia rufipes. Lepidoptera Tineidae appear on the head of mummified indoors corpses. North of parallel 32 degrees S, the Muscid grave-fly Ophyra sp. was found breeding on a corpse outdoors in summer. A division by latitude and climate is proposed for Argentina, and an extended system is proposed for the world.

Contribution of environmental factors to the risk of male infertility.

BACKGROUND: An increasing number of reports suggest that chemical and physical agents in the environment, introduced and spread by human activity, may affect male fertility in humans. We investigated the relationships between exposure to environmental agents and seminal characteristics, and the concentrations of reproductive hormones in the serum of men seeking infertility treatment. METHODS: We studied 225 male partners from consecutively recruited couples, who had their first infertility consultation between 1995 and 1998, in the Litoral Sur region of Argentina, one of the most productive farming regions in the world. RESULTS: A multivariate logistic regression model showed that exposure to pesticides and solvents is significantly associated with sperm threshold values well below the limit for male fertility. We also found that men exposed to pesticides had higher serum oestradiol concentrations, and that men exposed to solvents had lower LH concentrations than non-exposed men. All of these effects were greater in men with primary infertility than in men with secondary infertility. CONCLUSION: We have shown that environmental factors contribute to the severity of infertility, and that this may worsen the effects of pre-existing genetic or medical risk factors.