Prediction of Burst Pressure in Multistage Tube Hydroforming of Aerospace Alloys.

Bursting, an irreversible failure in tube hydroforming (THF), results mainly from the local plastic instabilities that occur when the biaxial stresses imparted during the process exceed the forming limit strains of the material. To predict the burst pressure, Oyan's and Brozzo's decoupled ductile fracture criteria (DFC) were implemented as user material models in a dynamic nonlinear commercial 3D finite-element (FE) software, ls-dyna. THF of a round to V-shape was selected as a generic representative of an aerospace component for the FE simulations and experimental trials. To validate the simulation results, THF experiments up to bursting were carried out using Inconel 718 (IN 718) tubes with a thickness of 0.9 mm to measure the internal pressures during the process. When comparing the experimental and simulation results, the burst pressure predicated based on Oyane's decoupled damage criterion was found to agree better with the measured data for IN 718 than Brozzo's fracture criterion.

Mastalgia: prevalence at a sub-saharan african tertiary hospital.

Introduction. Mastalgia is a common breast condition among women referred to breast clinics worldwide. Whereas the prevalence is known in the Western world and Asia, the prevalence of the disease is unknown in many African countries. The aim of this study therefore was to determine the prevalence and describe factors associated with mastalgia among women attending a tertiary hospital in sub-Saharan Africa. Methods. A cross-sectional study was done in Kampala, Uganda. Mastalgia was defined as self-reported breast pain (unilateral or bilateral) for a period not less than two months. A pretested questionnaire was used to collect the data and statistical analysis was performed using SPSS version 11. Ethical approval was obtained. Results. Out of the 1048 women who presented to the breast clinic during the study period, 168 (16%) were diagnosed with mastalgia in the absence of breast cancer. Noncyclical and cyclical mastalgia were 22/168 (13%) and 5/168 (3%), respectively. The onset of noncyclical category as compared to the cyclical type of mastalgia was observed to manifest before 24 years of age (P = 0.006). Conclusion. Mastalgia was a common condition among women in this sub-Saharan African setting as is elsewhere. The early onset mastalgia in this sub-Saharan African study requires further exploration for determination of its risk factors.

Reference values for serum levels of folic acid and vitamin B12 in a young adult Ugandan population.

INTRODUCTION: Reference values may vary significantly among populations and cultures for which dietary intakes may be different. Each laboratory is expected to investigate the transferability of the expected values to its own patient population and if necessary determine its own reference ranges. This study sought to establish Folic acid and Vitamin B(12) reference values for young Ugandan adults, which reference values could be used as baseline information for future research, especially related to their role in breast cancer prevention. METHODS: A cross sectional study in which 200 undergraduate student volunteers were enrolled. The minimum sample size was 126 using the Open Epi version 2. Relevant demographics and physical examination parameters were taken as well as blood samples for laboratory tests. Prior ethical approval was granted. RESULTS: The levels of folic acid were 4.17 - 20 ng/ml and remained constant over the age cohorts. The vitamin B(12) range was 117-1158 pg/ml. Both ranges were comparable to ranges seen in other populations. CONCLUSION: In as much as the dietary intake for this study population is presumed different from populations in the western countries, the ranges for these two vitamins were similar.

Selenium deficiency a factor in endemic goiter persistence in sub-Saharan Africa.

BACKGROUND: Goiter is still common in Uganda, despite the present iodized salt coverage of at least 95%. Where there is endemic goiter after adequate iodine supplementation, selenium deficiency could be a factor for the continued occurrence of goiter. The objectives of the present study, therefore, were to determine the serum selenium levels among goitrous patients and nongoitrous controls and to determine the association between goiter and selenium levels among these patients. METHODS: The investigation was designed as a case control study in which 92 subjects were enrolled, 46 cases and 46 controls of similar age and sex distribution. Subjects were interviewed and examined. Blood samples were taken and selenium concentrations were determined by electrothermal atomic absorption spectrometry. RESULTS: The overall mean serum selenium levels were 77.25 µg/l (SD 16.78) for the goiter patients and 95.50 µg/l (24.47) for the nongoiter controls. The difference between goitrous and nongoitrous populations was statistically significant (p=0.0001). Selenium levels above 102.8 µg/l had a statistically significant protective effect against goiter with adjusted odds ratio 0.3 (0.13-0.69); p=0.005. Other factors, such as age, main food constituent, and use of iodized salt, had no association with goiter. CONCLUSIONS: There were significant differences between selenium levels among goitrous patients and nongoitrous controls. High selenium levels seem to have a protective effect against goiter. Selenium supplementation as a preventive strategy is worth further exploration.

Thyroid Dysfunction among Young Adults in Uganda

Background: Most studies on thyroid dysfunction have been on patients refereed for treatment; little is known about the prevalence in the general populations. The importance of knowing such prevalence data lies in that fact that subclinical thyroid dysfunction is an important risk on development of heart disease; osteoporosis; hypercholesterolemia and mental illness. This study set out to determine thyroid dysfunction prevalence in a health young adult population. Methods: A cross sectional study carried out at the College of Health Sciences; Makerere University enrolled 100 Undergraduate medical students by invitations through notices and announcements. Informed consent was sought after approval from research ethics committee. Results: Of the 100 students enrolled and the samples drawn; 83 tests for TSH and 82 tests for FT4 were successfully run. Three results were abnormal making a prevalence of 3.6for thyroid dysfunction; a high TSH (5.71) with a normal fT4 (19.2); a normal TSH (1.67) with a high fT4 (22.31) and one with a low TSH (0.03). The mean age of participants was 23 years; there were slightly more males 1.3:1.Conclusion: The prevalence of thyroid dysfunction in this cohort was low but falls in the range found elsewhere. These findings could inform the criteria of screening asymptomatic otherwise young health adults

Cancer of the breast: 5-year survival in a tertiary hospital in Uganda.

The objective was to investigate survival of breast cancer patients at Mulago Hospital. A retrospective study of the medical records of 297 breast cancer patients referred to the combined breast clinic housed in the radiotherapy department between 1996 and 2000 was done. The female/male ratio was 24 : 1. The age range was 22-85 years, with a median of 45 years and peak age group of 30-39 years. Twenty-three percent had early disease (stages 0-IIb) and 26% had metastatic disease. Poorly differentiated was the most common pathological grade (58%) followed by moderately differentiated (33%) and well-differentiated (9%) tumours. The commonest pathological type encountered was 'not otherwise specified' (76%). Of all patients, 75% had surgery, 76% had radiotherapy, 60% had hormonotherapy and 29% had chemotherapy. Thirty-six (12%) patients received all the four treatment modalities. The 5-year survival probabilities (Kaplan-Meier) for early disease were 74 and 39% for advanced disease (P=0.001). The overall 5-year survival was 56%, which is lower than the rates in the South African blacks (64%) and North American whites (82-88%).

Missed injuries: a Ugandan experience.

BACKGROUND: Missed injuries (MIs) have been noted worldwide in all trauma centres that have studied them, and they are a significant cause of patient morbidity and mortality. OBJECTIVE: To establish the prevalence, contributing factors and short-term outcome of missed injuries in cases of multiple and major trauma. METHOD: Longitudinal prospective study involving 403 patients over 5 months. RESULTS: Missed injuries were discovered in 78 cases (prevalence 19.4%). Contributing factors included incomplete assessment (52.5%), radiological errors, surgical failures and patient's arrival time. The most affected body regions were the head and neck, extremities and pelvic girdle and contents; in the abdomen, 49.1% of injuries were missed. Among the 28 deaths in the study, 21 occurred in cases with missed injuries, and 13 (62%) of these deaths were directly attributable to missed injuries (R2=12.5, p=0.0001, 95% CI 5.5-28.35). CONCLUSION: There is need for improvement in patient assessment and monitoring, in efficiency of the trauma team, and for staff redistribution to address the increase in night arrivals.