Abstract The process of recovering metals from electronic waste has become an important topic in recent years. In this work, the recovery of electrolytic copper from the ashes produced during the pyrolysis process of waste electrical and electronic equipment (WEEE) was sought. Three gravimetric separation equipment were used: Wilfley table, JIG screen, and mechanical screen. This last method was used with and without previous grinding processes. The ashes were initially characterized by XRD to determine the phases present. The initial concentration of the ashes was carried out by physicochemical classification. The results obtained show that the JIG sieve separation processes obtained the best performance, reaching a percentage of about 87% of recovery of the metal present within the WEEE ashes during 16 minutes. The application of a vertical gravimetric separation system on material samples with a fairly wide density difference allowed an optimal separation system for the metallic material and the produced ash. On the other hand, the application of screens in the recovery of the metal obtains values much lower than those obtained by JIG sieve.

Vitamin B12 or cobalamin deficiency is a very common condition and is one of the most important causes of anemia. It can be treated with oral or intramuscular treatment. A summary of the evidence will be made through a systematic review of rando-mized clinical trials that have compared both treatments for the management of these patients. The objective of this review was to determine whether there is scientific evidence supporting the effectiveness of oral versus intramuscular vitamin B12 treatment ofits deficiency. The search strategy included randomized clinical trials (RCTs); databases used were: Medline, Cochrane Central, Lilacs and CINAHL. Also an electronic search in Google Scho-lar was performed. The results were three articles that met our eligibility criteria. We conclude that there is moderate evidence that the administration of oral vitamin B12 is most effective in the medium term increment serum cobalamin volume in patients with vitamin B12 deficiency.

La deficiencia de la vitamina B12 o cobalamina es una condición muy común y es una de las causas más importantes de la anemia. Puede ser tratada con un tratamiento oral o intramuscular. Se realizó una síntesis de la evidencia a través de una revisión sistemática de ensayos clínicos aleatorizados que hayan comparado ambos tratamientos para el manejo de estos pacientes. La estrategia de búsqueda incluyó ensayos clínicos aleatorizados (ECA); las bases de datos usadas fueron: Medline, Cochrane Central, Lilacs y Cinahl. Además se realizó una búsqueda electrónica en Google Scholar. Los resultados obtenidos fueron de tres artículos que cumplían con nuestros criterios de elegibilidad. El objetivo de esta revisión fue determinar si existe evidencia científica que avale la efectividad de la administración oral versus intramuscular de la vitamina B12 para el tratamiento de su deficiencia. Se concluyó que existe moderada evidencia que la administración de la vitamina B12 oral es más efectiva que la administración intramuscular a mediano plazo en el volumen sérico de cobalamina en pacientes con déficit de vitamina B12.

The hair follicle is a microscopic organ, functionally and structurally complex. It can be divided into two distinct segments, the upper portion, stable and the lower portion, that undergoes regeneration every hair cycle. The hair follicle contains a variety of cells types, including stem cells. It fact, it is the most important niche of stem cells in the skin, with the added advantage of its easy accessibility. These stem cells are located in a prominence at the level of the insertion of the arrector pili muscle, called bulge. They are responsible of hair follicle regeneration each hair cycle, and also can form sebaceous glands and help in repopulation of the interfollicular epidermis after injury. The knowledge of hair follicle structure is making possible the use of different types of cells, especially stem cells, in skin tissue engineering. Furthermore, recent studies have differentiated follicle stem cells into different strains, for example: nervous, hematopoietic and vascular cells. Moreover, other late studies have focused on the hair follicle construction, with satisfactory results in mice, but not completely transferable to humans, which further research is needed. The possibility of human hair follicle regeneration would suppose a revolution in the broad world of alopecia. The aim of this review is to describe the anatomical and histological structure of the hair follicle, emphasizing the importance as stem cell niche, and its potential usefulness in the field of tissue engineering for the construction of various types of tissues.

El folículo piloso-sebáceo o unidad folículo-sebácea-apócrina es un órgano microscópico complejo funcional y estructuralmente. Consta de un segmento superior, estable y un segmento inferior, que se regenera en cada ciclo piloso. El folículo piloso contiene una gran diversidad de tipos celulares, entre los que se encuentran células madre. De hecho, supone el nicho más importante de células madre en la piel, con la ventaja añadida de su fácil accesibilidad. Estas células madre se localizan en una prominencia a nivel de la inserción del músculo erector del pelo, llamada "bulge" (promontorio). Son las encargadas de regenerar el folículo en cada ciclo y también intervienen en la reconstitución de las glándulas sebáceas y de la epidermis interfolicular, en caso de lesión epidérmica. El conocimiento de la estructura del folículo piloso, está haciendo posible cada vez más el empleo de los distintos tipos celulares, especialmente, las células madre, en la ingeniería tisular de la piel. Asimismo, estudios recientes han diferenciado las células madres foliculares a diferentes estirpes, como por ejemplo: células nerviosas, hematopoyéticas y vasculares. Además, se ha estudiado la construcción de folículos pilosos, con resultados satisfactorios en ratones, aunque no del todo superponibles a humanos, en los que se precisan más investigaciones. La posibilidad de generar folículos pilosos humanos, supondría una revolución en el amplio campo de las alopecias. El objetivo de esta revisión es describir la estructura anatómica e histológica del folículo piloso, enfatizando en la importancia del mismo como nicho de células madre y su potencial utilidad en el campo de la ingeniería tisular, para la construcción de diversos tipos de tejidos.

Pressure ulcers are injuries to the skin and/or underlying tissues caused by prolonged high pressures on supporting body areas, they affect mainly people with poor mobility that have stayed in seating position for a long time. Reducing the amount and duration of pressure has been widely accepted for minimizing the risk of formation of pressure ulcers. Recently, dynamic cushions have been developed to relieve pressure on supporting areas; nevertheless, there is no sufficient information about the adequate characteristics of alternating sequences for pressure ulcers prevention. Therefore, the aim of this work is to explore three sequences of alternating movements designed for an air cell cushion by comparing pressure redistribution on supporting areas when applied on healthy volunteers. The purpose of these sequences is to redistribute the pressure over a larger contact area. To evaluate the effect of the alternating sequences, eight healthy volunteers were asked to sit on the air cell cushion, and to try the three alternating sequences for 12 minutes, 2 minutes on static mode and 10 minutes on alternating mode. A parameter for quantitative assessment of alternating sequences was proposed in this work by determining the coefficient of variation of interface pressure. Furthermore, the percentage of relative change of coefficient of variation was computed for evaluating performance of the alternating sequences comparing to the static mode. It was found that the three proposed strategies maintained values of interface pressure lower than previous work. Additionally, the relative change allowed to differentiate the effects of alternation of each sequence showing the second strategy as the most effective. The results are encouraging for further studies in subjects who require a wheelchair for mobility.

Las úlceras por presión son lesiones en la piel y tejidos subyacentes, causadas por presiones excesivas y prolongadas en las superficies de apoyo del cuerpo. Estas lesiones afectan principalmente a personas con poca movilidad física, como aquellas que permanecen sentados por largos periodos. Para disminuir el riesgo del padecimiento de estas lesiones, se ha recomendado como punto de partida reducir la magnitud y el tiempo de acción de las presiones en las zonas de apoyo. Se han desarrollado cojines dinámicos para sillas de ruedas, los cuales generan movimientos alternantes en las diferentes zonas de apoyo, producido por la inyección de aire, con el fin de disminuir las presiones en esas zonas. Sin embargo, no se han encontrado referencias de las características adecuadas de las secuencias de movimientos alternantes para prevenir la aparición de esas lesiones. El propósito de este trabajo es evaluar tres secuencias de movimientos alternantes diseñadas para un cojín de aire. La evaluación se realizó comparando la distribución de presiones en zonas de apoyo antes y durante la aplicación de estas secuencias alternantes en personas sanas. Las secuencias propuestas se aplican para el inflado y desinflado de celdas que forman el cojín y fueron diseñadas con el objetivo de distribuir las presiones en un área mayor de apoyo. La prueba se realizó en 8 sujetos sanos, con un tiempo de estudio de 12 minutos para cada secuencia diseñada; 2 minutos en modo estático y 10 minutos en modo alternante. Se propuso determinar el coeficiente de variación para evaluar de forma cuantitativa el efecto de las secuencias alternantes sobre la presión de interfaz. Además se calculó el porcentaje de variación relativa del coeficiente de variabilidad entre los modos basal (estático) y alternante como una herramienta para evaluar el desempeño de las secuencias propuestas en relación a la presión de interfaz. Se encontró que las tres estrategias mantuvieron presiones de interfaz por debajo de los valores reportados en trabajos previos. El porcentaje de variación relativa permitió diferenciar el efecto de la alternancia de cada una de las secuencias propuestas, mostrando la segunda estrategia como la más efectiva. Los resultados obtenidos son alentadores para continuar el estudio en sujetos que requieren una silla de ruedas para su movilidad.

Introduction: The prevalence of hyponutrition in hospitalized patients in our setting is 53%. The therapeutic approach is controversial. Objectives: To determine whether an early nutritional intervention in hospitalized patients by means of oral nutritional support can improve their prognosis regarding decreased morbimortality and hospital stay. Material and methods: Randomized prospective study comprised by a treatment group and a control group of malnourished patients hospitalized at the Internal Medicine and Respiratory Medicine Departments. The nutritional diagnosis was made by using the Subjective Global Assessment. Groups B and C were assigned to receive the hospital diet according to their needs and pathology (control group) and the treatment group also received a standard nutritional supplement. We recorded the development of infections, pressure ulcers, hospitalization days, mortality, and weight. Results: We performed more than 1,700 Subjective Global Assessments. Five hundred and thirty seven patients (264 treated and 273 controls) were followed-up until hospital discharge or death. We did not find statistically significant differences in mortality, hospital stay, or occurrence of complications between the treatment group and the control group. The treatment group presented statistically significant weight increase as compared with the control group. Conclusions: We could not demonstrate benefits when using the oral nutritional supplement in terms of mortality, hospital stay, infectious complications, or pressure ulcers. The significant weight increase in the treatment group allowed us concluding that the supplement effectively treated hyponutrition in this group. This new clinical status implies a better prognosis, as it has already been shown. However, this could not be observed by means of the study parameters. Long-term studies are required to determine for how long this nutritional improvement can be sustained, implying a better prognosis in the long run.

Introducción: La desnutrición en pacientes hospitalizados tiene una prevalencia en nuestro medio del 53%. El enfoque terapéutico genera opiniones controvertidas. Objetivos: Determinar si una intervención nutricional precoz en los pacientes hospitalizados desnutridos mediante un suplemento nutricional oral mejora el pronóstico de los mismos en términos de disminución de la morbi-mortalidad y estadía hospitalaria. Material y métodos: Estudio prospectivo randomizado integrado por grupo tratado-grupo control de pacientes hospitalizados desnutridos en áreas de medicina y neumología. El diagnóstico nutricional se realizó mediante Valoración Global Subjetiva. Los B y C se asignaron a recibir la dieta hospitalaria acorde a sus necesidades y patología (grupo Control) y al grupo tratado se lo instó además a ingerir un suplemento nutricional estándar. Se controló la aparición de infecciones, úlceras de presión, días de hospitalización, mortalidad y peso. Resultados: Se realizaron más de 1.700 Valoraciones Globales Subjetivas. Se controlaron hasta el alta hospitalaria o el fallecimiento a 537 pacientes, 264 tratados y 273 controles. No se encontraron diferencias estadísticamente significativas en la mortalidad, estadía hospitalaria, o aparición de complicaciones entre el grupo tratado y el control. El grupo Tratado presentó un aumento de peso con respecto al Control estadísticamente significativo. Conclusiones: No pudieron demostrarse beneficios con el suplemento nutricional oral utilizado en términos de mortalidad, estadía hospitalaria o complicaciones infecciosas ni úlceras de presión. El aumento significativo en el peso, en el grupo Tratado permite concluir que el suplemento trató efectivamente la desnutrición en este grupo. Esta nueva situación clínica significa un mejor pronóstico, como ya ha sido demostrado El mismo sin embargo no pudo objetivarse mediante los parámetros planteados. Estudios a más largo plazo se requieren para valorar cuánto esta mejoría nutricional se puede mantener en el tiempo, y signifique una mejoría en el pronóstico a largo plazo.

A degradabilidade in situ da matéria seca (MS) de silagens de milho em dois estados de maturidade (grão leitoso e meia linha de leite), de conhecida digestibilidade in vivo e in vitro, foi determinada com o propósito principal de comparar valores de digestibilidade com a degradabilidade no rúmen após 24 e 48h de incubação. Também foi analisada a cinética da digestão no rúmen, pelo modelo exponencial de McDonald, e foi calculada a degradabilidade efetiva, assumindo uma taxa de passagem de 4%/h. Dados de digestibilidade in vivo, in vitro e de degradabilidade in situ a 24 e 48h foram analisados com um modelo linear que incluiu o efeito do estado de maturação e metodologia de avaliação. Houve efeito significativo (P<0,05) da metodologia na estimação da digestibilidade, mas não foi encontrado efeito da maturação ou da interação maturação × metodologia. A digestibilidade in vivo (52,9%) não foi diferente da degradabilidade in situ a 24h (55,6%), e apresentou valores numéricos na amplitude dos valores da degradabilidade efetiva. A digestibilidade in vitro (61,6%) não foi diferente da degradabilidade in situ a 48h (61,9%), e ambas as alternativas foram maiores do que a digestilidade in vivo. A degradabilidade in situ a 24h de incubação é um bom preditor da digestibilidade in vivo da silagem de milho. Este parâmetro foi superestimado em 15-20% pela digestibilidade in vitro e pela degradabilidade in situ a 48h de incubação.

The in situ dry matter (DM) disappearance of corn silages in two maturity stages (milk grain and half milk line) of known in vivo and in vitro digestibility was determined, with the main purpose of comparing digestibility values with the ruminal disappearance at 24 and 48h of incubation. A secondary goal was the description of their ruminal digestion kinetics, from which the effective degradability was calculated at an assumed passage rate of 4%/h. Data of in vivo, in vitro and in situ degradability at 24 and 48-h were analyzed with a linear model that included as fixed effects the maturity and the methodology of evaluation, and the kinetic data were described by the exponential model of McDonald. There was a significant effect (P<0.05) of methodology in the estimation of digestibility, but not of maturity or interaction maturity × methodology. The in vivo digestibility (52.9%) was not different from the 24-h in situ degradability (55.6%) with numerical values in the range of the effective degradability. The in vitro digestibility (61.6%) was not different from the 48-h in situ degradability (61.9%), being both estimates higher than the in vivo digestibility. The 24-h in situ degradability was a closer estimator of the in vivo digestibility and the 48-h in situ degradability and the in vitro digestibility overestimated the in vivo parameter by 15-20%.

Foram realizadas duas cirurgias de prótese total da articulação coxofemoral em cão. Em um caso observou-se luxação caudal da prótese 72 horas após a cirurgia, que foi reduzida pelo método fechado, mantendo-se bandagem de Ehmer por 15 dias.O segundo caso evoluiu favoravelmente sem complicações pós-operatórias.Os dois pacientes foram avaliados periodicamente por 18 meses, mostrando desempenho clínico satisfatório, o que mostra a eficiência da técnica.

Two canine total hip replacements were performed. In one case, caudal luxation was observed 72 hours after the surgery, and it was treated by the closed reduction method, maintaining the Ehmer's sling for 15 days. The second case evoluted favourably without any postsurgical complication. Both patients were periodically evaluated during the 18 months that followed the surgery, showing a satisfactory clinical performance, that suggests the efficacy of the surgical technique.

O presente trabalho objetivou avaliar a associação de hialuronato de sódio e sulfato de condroitina no tratamento da doença articular degenerativa (DAD) em cães. Dez cães sem raça definida foram submetidos à secção artroscópica do ligamento cruzado cranial visando o desenvolvimento da DAD. Após 21 dias, foi substituído cirurgicamente o ligamento cruzado cranial em todos os animais e iniciado o tratamento com associação de hialuronato de sódio e sulfato de condroitina em cinco cães, sendo os remanescentes utilizados como grupo-controle. Avaliações artroscópica e radiológica do membro posterior esquerdo foram realizadas antes da secção do ligamento, no dia da sua substituição e 90 dias após a cirurgia. Histologicamente, o efeito da associação de hialuronato de sódio e sulfato de condroitina foi mais evidente na membrana sinovial, observando-se regeneração da camada íntima e diminuição da infiltração linfoplasmocitária na sub-íntima. Artroscópica e macroscopicamente não houve prevenção das lesões cartilaginosas decorrentes da DAD.

The aim of this study was the assessment of hyaluronic acid and chondroitin sulphate association in the therapy of degenerative joint disease (DJD) in dogs. Ten mongrel dogs underwent arthroscopic section of cruciate cranial ligament aiming the development of DJD. Twenty one days after the procedure, surgical substitution of cruciate cranial ligament was carried out in all animals. Then five animals were treated with the combination of hyaluronic acid and chondroitin sulphate. The other five dogs were used as controls. Arthroscopical and radiological evaluations of the left fore limb were carried out before arthroscopic section at the some day and 90 days after cruciate cranial ligament substitution. Histologically the effect of the association of hyaluronic acid and chondroitin sulphate was more evident in the synovial membrane that had regeneration of the intimal layer and reduced lympho-plasmocitic infiltrate in the sub-intimal layer. However, the treatment did not prevent DJD cartilage lesions evaluated by arthroscopy and radiology.

Avaliaram-se clínica e radiograficamente os efeitos do sulfato de condroitina e do hialuronato de sódio no tratamento da articulação femorotibiopatelar de cães com doença articular degenerativa (DAD) induzida experimentalmente. Foram utilizados 15 cães, sem raça definida, de ambos os sexos, pesando entre 18 e 25 kg, submetidos à secção artroscópica do ligamento cruzado cranial (LCCr) para desestabilização articular e indução da DAD. Após três semanas de instabilidade articular, o LCCr foi substituído utilizando-se a técnica intra-articular com emprego da fáscia lata. Os animais foram divididos em três grupos de cinco. Nos do grupo I fez-se somente a substituição do LCCr. Os do grupo II receberam 24mg/animal de sulfato de condroitina, via IM, de cinco em cinco dias, totalizando seis aplicações. Os do grupo III foram tratados com hialuronato de sódio na dose de 20mg/animal, via IV, de cinco em cinco dias, num total de três aplicações. Os animais foram observados por 90 dias, e avaliados clinicamente quanto à claudicação, à capacidade de suportar peso no membro afetado, à mensuração da atrofia muscular e à amplitude de movimento articular. Ao final, foram encaminhados para novo exame radiográfico. Os resultados demonstraram que os animais que receberam hialuronato de sódio apresentaram menor grau de claudicação quando comparados com os demais. Ao exame radiográfico observaram-se osteofitose periarticular e esclerose óssea subcondral. Essas alterações foram evidenciadas de forma mais acentuada nos animais tratados com hialuronato de sódio. Clinicamente, pôde-se observar melhor resultado com o hialuronato de sódio do que nos demais grupos, possivelmente devido à sua maior ação na membrana sinovial, reduzindo a dor e o grau de claudicação. O exame radiográfico não foi compatível com a sintomatologia clínica nos cães tratados com hialuronato de sódio.

The aim of this study was the evaluation of the effects of chondroitin sulfate and sodium hyaluronate in the knee joint of dogs with experimentally induced degenerative joint disease (DJD). Fifteen mongrel dogs, weighing 18 to 25kg were used. DJD was induced by cranial cruciate ligament (CCL) arthroscopical transection. After three weeks, CCL was repaired by an intrarticular technique, which uses fascia lata. The dogs were then divided into three groups as follows: group I received no other treatment, but the CCL reconstitution, group II received 24mg/animal of chondroitin sulfate/IM every five days, totaling six injections, and group III received 20mg/animal of sodium hyaluronate /IV every five days, totaling three injections. All dogs were examined clinically and radiographically for 90 days after the repairment surgery. The clinical evaluation was performed by assessment of lameness, weight-bearing, limb muscle atrophy and range of motion. The results demonstrated that the group treated with sodium hyaluronate had lower degree of lameness in comparison with other groups. The radiographic evaluation showed marginal osteophytes and subchondral bone sclerosis. These changes were more severe in the group treated with sodium hyaluronate. The better clinical results observed in this group, compared with the others, was probably due to the greater action of the drug in the synovium, decreasing the pain and lameness. Radiographic findings correlated poorly with the clinical signs in the group treated with sodium hyaluronate.