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Search Results: 1 - 10 of 152203 matches for " Martins O. Thomas "
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Mediastinal Masses: Pathophysiological Issues and Management Challenges in a Developing World  [PDF]
Martins O Thomas, Ezekiel O Ogunleye
Surgical Science (SS) , 2011, DOI: 10.4236/ss.2011.24047
Abstract: Context: Mediastinal masses occur worldwide. Compartmental occurrence and pathological variants vary widely, hence, the need for more studies. AIM: The study was conducted to further shed light on patho-physiological and current management challenges on mediastinal masses. Settings and Design: It was a pro-spective hospital based study spanning a period of 5 years. Methods and Materials: We gathered patients in series noting their ages and sex, presenting symptoms, investigation reports, treatment modalities and associ-ated postoperative complications. Statistical Analysis Used: Data was analysed manually looking at fre-quency distribution, correlation of malignancy with compartment involved and duration of symptoms against incidence of malignancy. Results: We saw 38 patients with significant male preponderance. Most tumours were in anterior mediastinum and population distribution was leptokurtic. Conclusions: Population distribu-tion of mediastinal masses is leptokurtic. The second to the fourth decades of life are mostly There was no correlation between occurrence of malignancy and the mediastinal compartment involved. Occurrence of malignancy had no bearing with duration of symptoms. affected. Most benign tumours are symptomatic and duration of symptoms is not discriminatory between benign and malignant variants. There is no correlation between occurrence of malignancy and the mediastinal compartment involved and occurrence of malignancy had no bearing with duration of symptoms.
Emergency Thoracotomy: Indications and Management Challenges in a Developing World  [PDF]
Martins O. Thomas, Ezekiel O. Ogunleye
World Journal of Cardiovascular Surgery (WJCS) , 2012, DOI: 10.4236/wjcs.2012.21001
Abstract: Background: Emergency thoracotomies often challenge surgical logistics and they tend to produce inferior outcomes when compared with elective surgery. Aims: We sought to identify the specific indications and therapeutic challenges that go with patients who undergo thoracotomy within 24 hours of admission and the re-thoracotomies. Methodology: Spanning a 7-year period, the bio-data of patients who met our criteria for emergency thoracotomies were collated. We noted their indications for surgery, therapeutic challenges and outcome of care. Results: In all, 36 patients (28 males and 8 females) met the inclusion criteria. Majority, (66.7%) fell into the 20 - 39 year age range. Diaphragmatic rupture was the commonest indication, followed by massive intra-thoracic haemorrhage. Postoperative mortality occurred in 11.1% of patients. Postoperative ventilation was absolutely indicated in 6 patients. Discussion and Conclusion: Diaphragmatic rupture is the commonest indication for emergency thoracotomy. We noted the need for improvement in pre hospital care for trauma patients as a way to improve the management outcome of emergency thoracotomies.
Aetiology and Demographic Attributes of Common Pleural Collections in an African Population  [PDF]
Ezekiel O. Ogunleye, Martins O. Thomas, Olugbenga O. Olusoji
Surgical Science (SS) , 2013, DOI: 10.4236/ss.2013.47066
Abstract:

Background: Fluids collect in the pleural space under different conditions and they are of different types. Detailed study of demographic attributes and aetiology of pleural collections has not been well reported in Africa. Aims and Objectives: This study was conducted to determine the demographic attributes and aetiology of common pleural space fluid collections. Methods: The sample population consisted of referrals received via clinics, admission through the emergency centre and wards. We noted their biodata, hospital identification numbers, ages and gender and other relevant parameters. Data analysis was done with special interest in gender-based diseases like ovarian carcinoma prostatic carcinoma and the like. Results: There were 372 patients over a 55-month period. The M:F ratio was 1:1 approximately. The combined mean age was 37.8 ± 0.92 years at 95% confidence interval. Their distribution was negatively skewed and it was leptokurtic. The age bracket of 20 - 49 had 65.6% of cases. There was gender based disparity in ages. Discussion: Malignant effusions constituted majority of sample size and the right side was consistently affected more often than the left side. Conclusion: Advanced malignancies are the commonest causes of pleural effusion. There is ongoing epidemiologic transition of diseases as the burden of non-communicable diseases is now juxtaposed with that of communicable diseases in Africa.

Adult Cardiac-Related Deaths: A Reflection of Epidemiologic Transition of Diseases in the Developing World?  [PDF]
Martins Oluwafemi Thomas, Nicholas A. Awolola, Olugbenga O Olusoji
World Journal of Cardiovascular Surgery (WJCS) , 2012, DOI: 10.4236/wjcs.2012.24020
Abstract:

Background: Epidemiologic transition of diseases is taking place globally. Therefore, it is necessary that more work is done to unravel the situation in respect to cardiac diseases in the developing world; Aim: The research was conducted to ascertain the cardiac causes of death in adults and by extension to further unravel the epidemiologic transition in relation to cardiac diseases in the developing world. Materials and Methods: This is an autopsy study of adult cardiac related causes of death in the year 2010 at the Lagos University Teaching Hospital in Nigeria, West Africa. It was conducted based in a 700-bedded hospital that has a catchment area of about 15 million people. Patients’ data (including bio-data, causes of death, etc.) were extracted from autopsy records for the year 2010. The data were entered and analysed with SPSS software. Results: There were 789 autopsies in the year and 99 of deaths were cardiac-related. There was male preponderance with a mean age of 54.2 ± 1.568 years. Hypertensive heart disease was the primary disease in 97.0% of cases in the studied sample. One 76 year old adult had myocardial infarction. There was no case of adult congenital heart disease. Intracerebral haemorrhage was the commonest cause of death. Discussion and Conclusion: Cardiovascular diseases constitute a growing threat to health among Africans. The developing countries are in stages II and III of Omran epidemiologic transition of diseases. This presents a major challenge to a large proportion of the world population with additional problem of poverty and ignorance. A 4-point agenda is suggested to reduce incidence of cardiovascular diseases (and deaths) in the developing world.

Bradyarrythmias: A Study of Anthropometric, Demographic and Comorbidity Profiles in an African Population  [PDF]
Martins Oluwafemi Thomas, Ezekiel O. Ogunleye, Olugbenga O. Olusoji, Augustin Olugbemi, O. O. Ojo
World Journal of Cardiovascular Surgery (WJCS) , 2013, DOI: 10.4236/wjcs.2013.37041
Abstract: Background: Bradyarrhythmias are a group of cardiac rhythm disorders that are characterized by bradycardia and they are cosmopolitan in distribution. Their demographic, anthropometric and comorbidity attributes are yet to be clearly established in Africa. Aims and Objectives: This study was conducted to determine the anthropometric, demographic and comorbidity factors in an African population. Methods: We got data from two groups of patients—Group A were bradyarrhythmia patients who already had permanent pacemaker insertion (PPI). Group B were non-cardiac non-debilitated patients of similar age bracket. The sample population consisted of referrals received via clinics, admission through the emergency centres and wards. Their bio-data, hospital identification numbers, ages and gender and other relevant parameters were carefully documented. The ensuing data was analyzed with SPSS 21 statistical software. Results: There were 31 patients in group A (17 male and 14 female patients) and 36 in group B (22 male and 14 female patients). They were all above 20 years of age. Group A had a mean age of 65.8 ± 4.76 years while group B had a mean age of 62.2 ± 4.47 years. Body Mass Index (BMI ≥ 25 Kg·m2), elevated BP, and diabetes mellitus were important clinical attributes of bradyarrhythmias in the studied group. Discussion and Conclusion: Our study showed that the stated anthropometric, demographic and comorbidity parameters are important attributes for bradyarrhythmias in African population.
Chemical injuries of the oesophagus: aetiopathological issues in Nigeria
Martins O Thomas, Ezekiel O Ogunleye, Oladapo Somefun
Journal of Cardiothoracic Surgery , 2009, DOI: 10.1186/1749-8090-4-56
Abstract: The aim of the study was to determine the aetiopathological pattern of chemical injuries of the oesophagus in Nigeria.This is a multi-centre hospital based study in Lagos metropolis spanning a period of 10 years.The patients' bio data, substances ingested, sources of corrosives, reasons for ingesting corrosives and patients' mental state were recorded.In all, there were 78 patients (61 Males, 17 Females). The offending agents were acids in 55.1% of cases and it was accidental ingestion in 62 patients. The highest incidence of 57.6% was found in the middle 1/3 of the oesophagus.Accidental ingestion of acids is the commonest cause of oesophageal injuries in Nigeria. The incidence of severe strictures necessitating oesophageal substitution could be reduced if early management of corrosive oesophagitis improves in Nigeria.Chemical injuries of the oesophagus are caused by ingestion of corrosives like acids, alkali and some neutral substances. Other causes of oesophagitis include autoimmune diseases, infection, radiation and gastro-oesophageal reflux disease (GERD) [1-13].Ingested corrosives produce oro-pharyngeal and gastro-oesophageal injuries ranging from minor burns to severe necrosis, depending on the agent, the quantity ingested, concentration and duration of exposure. This may lead to corrosive strictures of the oesophagus [2].Various aspects of corrosive strictures of the oesophagus have been studied worldwide. A report from Ibadan, in South-Western Nigeria, by Ajao, OG and Solanke, TF [3] concluded that the commonest cause of benign oesophageal stricture is ingestion of corrosives.Acids tend to burn the oral cavity, pharynx or larynx at the upper end and the pylorus is often damaged with copious ingestion of acids. Attempt at spiting out the acid may lead to tell-tale signs on the skin of the chest.Alkalis tend to affect the body of the oesophagus, especially at areas of natural constrictions. Powdery substances like calcium carbide do not glide easily in the oes
Laser absorption via QED cascades in counter propagating laser pulses
Thomas Grismayer,Marija Vranic,Joana L. Martins,Ricardo A. Fonseca,Luis O. Silva
Physics , 2015,
Abstract: A model for laser light absorption in electron-positron plasmas self-consistently created via QED cascades is described. The laser energy is mainly absorbed due to hard photon emission via nonlinear Compton scattering. The degree of absorption depends on the laser intensity and the pulse duration. The QED cascades are studied with multi-dimensional particle-in-cell simulations complemented by a QED module and a macro-particle merging algorithm that allows to handle the exponential growth of the number of particles. Results range from moderate-intensity regimes ($\sim$ 10 PW) where the laser absorption is negligible, to extreme intensities (> 100 PW) where the degree of absorption reaches 80%. Our study demonstrates good agreement between the analytical model and simulations. The expected properties of the hard photon emission and the generated pair-plasma are investigated, and the experimental signatures for near-future laser facilities are discussed.
Particle Merging Algorithm for PIC Codes
Marija Vranic,Thomas Grismayer,Joana L. Martins,Ricardo A. Fonseca,Luis O. Silva
Physics , 2014, DOI: 10.1016/j.cpc.2015.01.020
Abstract: Particle-in-cell merging algorithms aim to resample dynamically the six-dimensional phase space occupied by particles without distorting substantially the physical description of the system. Whereas various approaches have been proposed in previous works, none of them seemed to be able to conserve fully charge, momentum, energy and their associated distributions. We describe here an alternative algorithm based on the coalescence of N massive or massless particles, considered to be close enough in phase space, into two new macro-particles. The local conservation of charge, momentum and energy are ensured by the resolution of a system of scalar equations. Various simulation comparisons have been carried out with and without the merging algorithm, from classical plasma physics problems to extreme scenarios where quantum electrodynamics is taken into account, showing in addition to the conservation of local quantities, the good reproducibility of the particle distributions. In case where the number of particles ought to increase exponentially in the simulation box, the dynamical merging permits a considerable speedup, and significant memory savings that otherwise would make the simulations impossible to perform.
Seeded QED cascades in counter propagating laser pulses
Thomas Grismayer,Marija Vranic,Joana L Martins,Ricardo Fonseca,Luís O Silva
Physics , 2015,
Abstract: The growth rates of seeded QED cascades in counter propagating lasers are calculated with 2D/3D QED-PIC simulations. The dependence of the growth rate on laser polarisation and intensity are compared with analytical models that support simulations results. The models provide an insight regarding the qualitative trend of the cascade growth when the intensity of the laser field is varied. The results suggest that relativistic pair plasmas and efficient conversion from laser photons to gamma rays can be created with the typical intensities planned to operate on future ultra-intense laser facilities such as ELI or VULCAN.
Chronic Empyema: Aetiopathology and Management Challenges in the Developing World  [PDF]
Martins Oluwafemi Thomas, Ezekiel Olla Ogunleye
Surgical Science (SS) , 2011, DOI: 10.4236/ss.2011.29097
Abstract: Objectives: Chronic empyema thoracis (CET) is common worldwide despite widespread use of highly effective antibiotics. Also, newer technological armamentaria are available for its diagnosis and treatment. This research was performed to study the aetiopathological profile and the management challenges of CET in view of the background information stated above. Methods: It is a prospective study spanning a period of 62 months in Lagos, Nigeria. Patients’ bio-data, aetiological factors, salient clinical features, management modalities and complications of care were documented and analysed. We excluded patients who were not fit for surgery and those who could not afford surgery. Patients that were initially registered as chronic empyema patients but who later became positive for malignancy were also excluded. Results: There were 93 patients (61 males and 31 females). Age range was 4-72 years but the range 20-49 years constituted 71.0% of the studied population. Poorly treated acute chest infections was the aetiological factor in 49.5% of patients. Tuberculosis was established in 37 patients (39.8%) who were especially in social classes I and II. Decortication and pneumonectomy were done for 52.7% and 16.1% of the patients respectively. Average hospitalisation was prolonged for pneumonectomy because some patients had pneumonectomy space infections. Discusion: CET remains a worldwide problem despite widespread use of potent antibiotics. There are newer diagnostic and therapeutic armamentaria that are not readily available in developing world thereby posing major challenges to practicing surgeons.
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