RESUMO
There is a significant need for models that can capture the mechanical behavior of complex porous lattice architectures produced by 3D printing. The free boundary effect is an experimentally observed behavior of lattice architectures including the gyroid triply periodic minimal surface where the number of unit cell repeats has been shown to influence the mechanical performance of the lattice. The purpose of this study is to use finite element modeling to investigate how architecture porosity, unit cell size, and sample size dictate mechanical behavior. Samples with varying porosity and increasing number of unit cells (relative to sample size) were modeled under an axial compressive load to determine the effective modulus. The finite element model captured the free boundary effect and captured experimental trends in the structure's modulus. The findings of this study show that samples with higher porosity are more susceptible to the impact of the free boundary effect and in some samples, the modulus can be 20% smaller in samples with smaller numbers of unit cell repeats within a given sample boundary. The outcomes from this study provide a deeper understanding of the gyroid structure and the implications of design choices including porosity, unit cell size, and overall sample size.
RESUMO
An observational cross-sectional study conducted in Kingston in 2004 showed that seat belts were used by 81.2% of private motor vehicle drivers and 74.0% offront seat passengers. This was significantly improved compared to 21.1% and 13.6% respectively in 1996 before the introduction of legislation in 1999 (p < 0.001). Females were significantly more likely than males to wear seat belts, both when driving (92.5% vs 77.3%; p < 0. 001) and as front seat passengers (79.9% vs 66.3%; p < 0.001). Of the 2289 motor vehicles examined, all except one were equipped with seat belts. Rear passenger utilization of seat belts was not examined. Drivers of new vehicles were more likely than other drivers to use seat belts (p < 0.001). Male drivers, drivers of older vehicles and all passengers may require specific targeting in an educational and enforcement campaign if the maximum benefits of seat belt use are to be realized
Un estudio transversal observacional llevado a cabo en Kingston en el año 2004 mostró que los cinturones de seguridad eran usados por el 81.2% de los conductores de vehículos motorizados privados, y el 74.0% de los pasajeros del asiento delantero. Esto representa una mejoría significativa en comparación con el 21.1% y el 13.6% respectivamente en 1996 antes de que se introdujera la legislación en 1999 (p < 0.001). Las tendencia de las mujeres a usar cinturones de seguridad fue significativamente mayor que la de los hombres, tanto al conducir (92.5% vs 77.3%; p < 0.001) como al viajar como pasajeras en el asiento delantero (79.9% vs 66.3%; p < 0.001). De los 2289 vehículos motorizados examinados, todos excepto uno estaban equipados con cinturones de seguridad. No se examinó la utilización de los cinturones de seguridad por parte de los pasajeros en los asientos traseros. Los conductores de vehículos nuevos mostraron una tendencia mayor que los otros conductores a usar cinturones de seguridad (p < 0.001). Los conductores varones, los conductores de vehículos más viejos, y todos los pasajeros puede que requieran ser objeto específico de una campaña destinada a educarlos o a hacer cumplir la ley si se desea maximizar los beneficios del uso del cinturón de seguridad.
Assuntos
Humanos , Masculino , Feminino , Cintos de Segurança , Cintos de Segurança/legislação & jurisprudência , Distribuição de Qui-Quadrado , Estudos Transversais , Fatores Sexuais , Jamaica/epidemiologia , Prevalência , SeguimentosRESUMO
This prospective, observational one-year study analyzed 623 patients who were 60 years and older, out of a cohort of 2375 patients who were admitted consecutively to the general surgery wards of the University Hospital of the West Indies (UHWI). Even though only 9.7% of the Jamaican population are 60 years and older, this age group accounted for 26.2% of total admissions. Comparison of elderly and non-elderly patients showed no differences in gender, but less elderly patients were emergency admissions (52% vs 64%, p < 0.001), more underwent surgery (68% vs 60%, p < 0.001), their mean hospital stay was longer (11.5 vs 8.0 days, p < 0.001) and their mortality rate was higher (8.8% vs 1.9%, p < 0.001). Emergency admissions (52%) exceeded elective admissions in the elderly. Forty-four (80%) of the 55 deaths in the elderly group were admitted as emergencies compared to elective admissions (p < 0.001). There were 11 deaths among the 296 elective admissions (3.7%) but 44 deaths among the 327 emergency admissions (13.5%), a significant difference in mortality rates (p < 0.001). Overall, the death rate for males was higher. Cancer was the commonest admission diagnosis (21%) and that amongst mortalities. Steps to improve the opportunities for earlier admission and optimization of care of elderly surgical patients would not only benefit them but would be an important step towards a more efficient use of already scarce resources
Este estudio observacional prospectivo de un año analizó 623 pacientes de 60 años de edad o más, de una cohorte de 2375 pacientes que fueron admitidos consecutivamente a las salas de cirugía general del Hospital Universitario de West Indies. Aunque sólo 9.7% de la población jamaicana tiene 60 años de edad o más, este grupo etario representó el 26.2% del total de ingresos. La comparación de pacientes mayores con no mayores no mostró ninguna diferencia en cuanto a género, pero los pacientes menos mayores fueron ingresos de emergencia (52% vs 64%, p < 0.001), más necesitaron cirugía (68% vs 60%, p <0.001), su período medio de estancia en el hospital fue más largo (11.5 vs 8.0 días, p <0.001) y su tasa de mortalidad fue más alta (8.8% vs 1.9%, p < 0.001). Los ingresos de emergencia (52%) excedieron a los ingresos electivos dentro del grupo de los pacientes mayores de edad. Cuarenta y cuatro (80%) de las 55 muertes en el grupo de mayores de edad fueron pacientes ingresados como emergencias en comparación con los ingresos electivos (p < 0.001). Se produjeron 11 fallecimientos entre las 296 admisiones electivas (3.7%) pero 44 muertes entre las 327 admisiones de emergencia (13.5%), una diferencia significativa en la tasa de mortalidad (p < 0.001). Por regla general, la tasa de mortalidad entre los hombres fue más alta. El cáncer fue el diagnóstico más común (21%) entre los ingresos y la causa más frecuente de las mortalidades. Los pasos para mejorar las oportunidades de ingreso temprano y optimizar la atención a pacientes quirúrgicos ancianos, no sólo redundaría en beneficio de estos últimos, sino que representaría también un paso importante hacia un uso más eficaz de recursos que están escasos.
Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Operatórios/mortalidade , Distribuição de Qui-Quadrado , Estatísticas não Paramétricas , Estudos Prospectivos , Fatores Etários , Fatores de Risco , Tempo de Internação/estatística & dados numéricos , Índias Ocidentais/epidemiologiaRESUMO
The aim of this study was to examine the clinical and pathological characteristics of colorectal cancer in Jamaica, to determine whether there was a change in the anatomic distribution and clinical presentation and to discuss the options for diagnosis and management. A comprehensive retrospective review of patients newly diagnosed with colorectal carcinoma was conducted at The University Hospital of the West Indies by reviewing both patient records and pathological data. These data were compared with previous reports of patients with colorectal cancer seen in Jamaica. One hundred and forty-seven patients were studied There were 85 females and 62 males with a female to male ratio of 1.37:1. The median age was 65.5 years (range 19 to 94 years). The predominant symptoms were abdominal pain in 91 patients, change in bowel habit in 77 patients and rectal bleeding in 74 patients. Sixty patients presented with weight loss and 28 with a rectal mass. The most common tumours were right-sided colonic cancers in 42 patients (28.5) followed by sigmoid colon in 30 (20.4) rectum in 34 (23.1) and left and transverse colon accounting for 16 and 10 cases respectively. Most of the tumours were well or moderately differentiated adenocarcinomas. Only eight patients presented with Dukes' A disease, 50 with Dukes'B, 53 with Dukes'C disease and 34 with advanced disease. The findings showed that sigmoid and rectal tumours accounted for 43.5 of cancers. The colon/rectum ratio in this series was 3.3:1 indicating a significant proximal shift of colorectal cancers in this population in keeping with recent reports. The results of the current study suggest that the sub-site location of colorectal cancers seen is similar to that reported in high incidence countries such as the United States of America and parts of Europe but differs from the African continent which has a high proportion of rectal tumours. This right-sided preponderance also differs from previous studies in Jamaica, which report a higher incidence of rectal lesions The detection of early colorectal carcinoma will require screening at a stage when the disease is asymptomatic in order to improve the chance for cure. The data presented here imply that screening programmes should allow evaluation of the entire colon rather than the distal 25 cm
Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Neoplasias Colorretais/epidemiologia , Distribuição por Idade , Distribuição por Sexo , Estadiamento de Neoplasias , Hospitais Universitários , Incidência , Jamaica/epidemiologia , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/fisiopatologia , Área Programática de SaúdeRESUMO
This study reports the first 13 cases of biopsy-proven low rectal carcinoma treated by transanal electrocoagulation using a locally manufactured instrument. At the University Hospital of the West Indies, over a 16-year period, 9 patients were treated for cure, six of whom have no clinical evidence of recurrence for one to 12 years. Four cases who were offered this procedure for palliation defaulted after a single treatment. Transanal electrocoagulation provides an additional option for treating patients with small, mobile low rectal cancers, following careful screening for evidence of nodal or distant spread. The procedure can also be used in the local control of disease in patients with distant spread or in whom a major operation is not feasible.
Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Adenocarcinoma/cirurgia , Eletrocoagulação , Neoplasias Retais/cirurgia , Eletrocoagulação/instrumentação , Eletrocoagulação/métodosRESUMO
Granulosa-theca cell tumours are ovarian neoplasms of low malignancy with hormone secreting potential, accounting for 2-3of all ovarian cancers. They have an uncertain clinical course and a potential for late recurrence after surgical removal. Clinical features of a patient presenting with pulmonary metastases 21 years after removal of the primary tumour are described, along with a review of the management options.
Assuntos
Humanos , Feminino , Pessoa de Meia-Idade , Tumor de Células da Granulosa , Neoplasias Ovarianas/patologia , Neoplasias Pulmonares/secundário , Bignoniaceae/secundário , Tumor de Células da Granulosa , Neoplasias Ovarianas/cirurgia , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/cirurgia , Ovariectomia , Pneumonectomia , Seguimentos , Bignoniaceae/patologia , Bignoniaceae/cirurgiaRESUMO
Inflammatory pseudotumour of the orbit is an unusual condition of unknown aetiology which rarely extends beyond the orbit. To our knowledge 19 cases with intracranial extension have been reported, none of which involved the pituitary fossa or sphenoid sinus. Most required cytotoxic agents, surgery or radiotherapy in addition to corticosteroids. We present a case of orbital pseudotumour with extension into the pituitary fossa, sphenoid sinus and cavernous sinuses with vascular compression. Marked clinical improvement occurred on steroid therapy alone.
Assuntos
Humanos , Feminino , Adulto , Pseudotumor Orbitário , Encéfalo/patologia , EncéfaloRESUMO
A case of gastric outler obstruction following acid ingestion in a 2 1/2 years-old chilod is reported. The characteristic features of this injury are minor injury to the mouth, pharynx and oesophagus, and major injury to the stomach. a small amount of acid can produce considerable damage to the stomach. Therefore all patients require admission to hospital. Early barium meal examination and, if available, flexible endoscopy, will identify the extent of damage so as to avoid early discharge of patients when gastric perforation is likely. Emphasis is placed on the need for public education in the prevention of ingestion of corrosive substance bu children
Assuntos
Pré-Escolar , Humanos , Masculino , Estenose Pilórica/induzido quimicamente , Queimaduras Químicas/complicações , Ácidos SulfúricosRESUMO
A prospective analysis of 150 temporay tube gastrostomies performed over two 12-mounth periods is presented. All were carried out at the time of another abdominal surgical procedure and were intende for post surgical procedure and to any tube-related complications. Gastrostomu was found to be a safe, comfortable and effective method of achieving prolonged gastric decompression, an its use is recommended in selected patients