ABSTRACT
Abstract The electrospinning device is used in the biomaterials research field nowadays for fabricating nanofibers that can be used for manufacturing artificial skin and muscular tissue, blood vessels (vascular grafts), orthopedic components (bones, cartilages, and ligaments/tendon), and peripheral or central nervous system components. Electrospun nanofibers act as ideal scaffolds for tissue engineering and drug delivery systems because they can mimic the functions of native extracellular matrices. A low cost electrospinning device was designed and built for undergraduate practical learning in the Biomaterials course in the area of Bioengineering at Universidad Autónoma de Baja California, México. The methodology includes 3D CAD designing, manufacturing of the acrylic cabinet, different collectors and the fabrication of poly (vinyl alcohol) nanofibrous scaffolds, in order to validate the functionality of the electrospinning system. The prototype is an affordable device; its cost is 95% less than the laboratory commercial devices.
Resumen El dispositivo de electrohilado es actualmente empleado en la investigación de biomateriales, utilizado para sintetizar nanofibras que ofrecen un potencial para la manufactura de piel artificial y tejido muscular, vasos sanguíneos (implantes vasculares), componentes ortopédicos (hueso, cartílago y tendones/ligamentos) y componentes del sistema nervioso central y periférico. Las nanofibras producidas por electrohilado pueden ser usadas como andamios ideales para ingeniería de tejidos y liberación controlada de fármacos debido a que mimetizan las funciones de la matriz extracelular. El dispositivo de electrohilado de bajo costo fue diseñado y construido para al aprendizaje practico de estudiantes de licenciatura en la asignatura de Biomateriales de la carrera de Bioingeniería. La metodología incluye diseños CAD 3D, manufactura del gabinete de acrílico, diferentes colectores y fabricación de los andamios de nanofibras de Poli (vinil alcohol) para validar la correcta funcionalidad del sistema de electrohilado. El prototipo es un dispositivo accesible económicamente, su costo es un 95% más barato que los dispositivos de tipo comercial.
ABSTRACT
PURPOSE To evaluate the magnitude of systematic and random errors from a subset of 100 prostate and 26 head and neck (H&N) cancer patients treated with conventional conformal radiotherapy and using image-guided radiotherapy (IGRT). After treatment, the uncertainties involved and the CTV to PTV margin were evaluated. MATERIAL AND METHODS An Elekta Synergy® linear accelerator was used, taking advantage of 3D on-board computed tomography. IGRT with no-action level (NAL) protocol was applied, reporting the 3D translation and rotation corrections. A statistical study was performed to analyse systematic, random and interobserver uncertainties, and, finally, to obtain the CTV to PTV margins. RESULTS The H&N patients' uncertainties found were smaller than those of prostate patients. The CTV to PTV margins assessed, following the guidelines found in the literature, in the three dimensions of space (right-left, superior-inferior, anterior-posterior) were (5.3, 3.5, 3.2) mm for H&N and (7.3, 7.0, 9.0) mm for prostate cancer treatments. CONCLUSIONS It was found that assessing all the involved uncertainties within radiation treatments was very revealing; their quality improves using IGRT techniques and performing extensive data analysis.
Subject(s)
Head and Neck Neoplasms/radiotherapy , Prostate/diagnostic imaging , Prostatic Neoplasms/radiotherapy , Cone-Beam Computed Tomography , Head and Neck Neoplasms/diagnostic imaging , Humans , Male , Particle Accelerators , Prostatic Neoplasms/diagnostic imaging , Radiotherapy Planning, Computer-Assisted/methods , Radiotherapy, Conformal , Radiotherapy, Image-Guided/methods , UncertaintyABSTRACT
OBJECTIVE: To describe and identify the causes of an outbreak of Salmonella enteritidis gastroenteritis that took place in June 1998, among tertiary care hospital workers, in Mexico City. MATERIAL AND METHODS: Cases were hospital workers who developed diarrhea or fever associated with gastrointestinal symptoms, after a meal at the hospital's dining room on June eight; controls were asymptomatic employees who also ate at the hospital's dining room on the same day. A food questionnaire was applied, and stool samples were obtained from all study subjects, including kitchen personnel. Blood cultures were practiced for febrile patients. Odds ratios with 95% confidence intervals (95% CI) and the chi-squared were used for statistical analysis. Statistical significance was set at p < 0.05. RESULTS: One-hundred-fifty-five workers developed symptoms, but only 129 (83.2%) answered the questionnaire; 150 controls were also studied. The most common symptoms were diarrhea (85%), abdominal pain (84%), cephalea (81.4%), nausea (78.3%), and chills (74.4%). Eight blood cultures were negative; 59 stool cultures (46%) from cases and six (4%) from controls, were positive for Salmonella enteritidis. Egg-covered meat was the suspected source of infection (OR 19.39, 95% CI 9.09-41.4); some other foodstuffs like fruit dessert and yogurt, were significantly more frequent in cases than in controls. Food cultures were all negative. CONCLUSION: This outbreak was probably caused by Salmonella-contaminated foodstuffs (egg-covered meat with potatoes) due to deficient cooking. This report shows the importance of food-quality programs for hospital meals.
Subject(s)
Disease Outbreaks , Gastroenteritis , Occupational Diseases , Personnel, Hospital , Salmonella Infections , Adolescent , Adult , Aged , Catchment Area, Health , Female , Foodborne Diseases/diagnosis , Foodborne Diseases/epidemiology , Foodborne Diseases/microbiology , Gastroenteritis/diagnosis , Gastroenteritis/epidemiology , Gastroenteritis/microbiology , Humans , Male , Mexico/epidemiology , Middle Aged , Occupational Diseases/diagnosis , Occupational Diseases/epidemiology , Occupational Diseases/microbiology , Salmonella Infections/diagnosis , Salmonella Infections/epidemiology , Salmonella Infections/microbiology , Surveys and QuestionnairesABSTRACT
A case of primary congenital hipothyroidism, with acentuated symptoms of myxdema together with great psychic and physical deficiency, is referred to. The out standing clinical findings were an increase in pubic hair and sings to right ventricular hypertrophy, whose pathogeny is commented. The clinical evolution after three years of treatment, and the necessity of begining treatment as early as possible so as to obtain greater efficiency in the recuperation of psychic deficency, is also referred to.
