Development of polymer wicks for the fabrication of bio-medical sensors

Polymer based wicking structures were fabricated by sintering powders of polycarbonate (PC), ultra-high molecular weight polyethylene and polyamide 12, aiming at selecting a suitable material for an innovative electroencephalography (EEG) bio-electrode. Preliminary experiments showed that PC based wicks displayed the best mechanical properties, therefore more detailed studies were carried out with PC to evaluate the influence of powder granulometry and processing parameters (pressure, temperature and time) on the mechanical properties, porosity, mean pore radius and permeability of the wicks. It was concluded that the mechanical properties are significantly enhanced by increasing the processing time and pressure, although at the expense of a significant decrease of porosity and mean pore diameter (and thus permeability), particularly for the highest applied pressures (74kPa). However, a good compromise between porosity/permeability and mechanical properties could be obtained by sintering PC powders of particle sizes below 500μm at 165°C for 5min, upon an applied pressure of 56kPa. Moreover, PC proved to be chemically stable in contact with an EEG common used disinfectant. Thus, wicking structures with appropriate properties for the fabrication of reusable bio-electrodes could be fabricated from the sintering of PC powders.

DOTA-based Ga(III) and Gd(III) chelates for medical imaging (PET, SPECT and MRI)

PhD Thesis in Sciences Specialization in Chemistry

Level of compliance in contact lens wearing medical doctors in Nepal

PURPOSES: To determine the level of compliance and major non-compliant behaviors in contact lens (CL) wearing medical doctors (MDs) and to compare it with age matched CL wearing normal subjects with no medical background (NS). METHODS: Thirty-nine current CL wearing MDs, who were prescribed CLs in Nepal Eye Hospital, Kathmandu, Nepal, between 2007 and 2011, were interviewed on ten modifiable compliant behaviors regarding lens care and maintenance. The level of compliance and the rate of non-compliance for each behavior were determined and compared with NS. RESULTS: Level of compliance was good, average and poor in 35.9%, 48.7% and 15.4% of MDs, respectively. There was no significant difference in compliance between MDs and NS (p=0.209). Level of compliance was not associated with age, gender and duration of lens wear (p>0.05). Compliance rate varied according to different behaviors, achieving a good compliance level of 95% for hand hygiene, avoidance of water contact and not sleeping with lenses. There was poor compliance for topping up solution (53.8%) and lens case replacement (15.4%). CONCLUSION: About one third of MDs had a good level of compliance. Level of compliance and compliance rate of different behaviors were similar in MDs and NS. Periodic lens case replacement was the most neglected behavior in CL wearers for this region.

Common mental disorders among medical students

OBJECTIVE: Common mental disorders (CMD) have a high impact on interpersonal relationships and quality of life and are potential underlying causes for the development of more serious disorders. Medical students have been indicated as a risk population for the development of CMD. The aim of this study was to determine the frequency of CMD in undergraduate medical students and to identify related factors. METHODS: A cross-sectional study was performed in a sample population of medical students. CMD was identified according to the 20-item Self-Report Questionnaire. RESULTS: Two hundred and twenty-three students completed the questionnaire. The overall prevalence of CMD was 29.6% and its presence was independently associated with sleep disorders, not owning a car, not working and sedentary lifestyle. CONCLUSIONS: These findings indicate a high prevalence of CMD in the sample studied and are important for supporting actions to prevent mental disorders in future doctors and for reflecting on the curricula currently in use in medical schools.

Development of procedures for the design, optimization and manufacturing of customized orthopaedic and trauma implants: Geometrical/anatomical modelling from 3D medical imaging

Tese de Doutoramento (Programa Doutoral em Engenharia Biomédica)

Treating the entire person

[Excerpt] A critical case from a Portuguese hospital reveals how the ultimate healthcare customer, the patient, is a complete system, not a jumble of parts. (...) The lean production philosophy has made inroads into service sectors, including medical care in the United Kingdom and the United States. Unfortunately, numerous medical organizations in those two countries and the rest of the world treat patients like they are made up of parts, not as a whole system. This leads to disjointed handoffs, bottlenecks in information flow that delay treatment, and sending the patient back and forth from department to department. The following case in Portugal shows how most of the world’s health systems still suffer from functional silos and how waste is all over the place. In this case, the missing links in communication between doctors, nurses, auxiliary staff, the patient and her family led to the patient’s death. Adopting lean healthcare with its proven tools would be a solution to many of the problems described. When a patient dies in a hospital, the family often is told that the doctors did everything they could. Normally, that is the case, as healthcare providers – doctors, nurses, auxiliary staff, therapists – do their best with the system they have.

Prevalence of depressive and anxiety symptoms in medical students in the city of Santos

ABSTRACT Objective Ascertain the prevalence of depressive and anxiety symptoms in medical students, considering data in the literature that indicate higher vulnerability to emotional disorders in this population. Methods A descriptive cross-sectional study with a sample of 657 (98%) students. The instruments used were: questionnaire of socioeconomic-demographic characteristics, Beck Depression Inventory and Beck Anxiety Inventory. Results Predominance of the female gender (61%), aged between 17 and 30 years (98%), Catholic religion (64.2%) from the city of São Paulo (40.7%) and other cities in the state (35.7%); 30% presented depressive symptoms and 21% anxiety symptoms. Female students had higher scores both for depression (34.8%) and for anxiety (26.8%). As regards the course year, the highest rates were found in the 5th year (40.7%) for depression and in the 2nd year for anxiety (28.8%). Conclusion The data obtained in this study (30%) agreed with the literature regarding the prevalence of depressive symptoms in medical students, but this index was higher compared to the population in general (15.1% to 16.8%), and related to people in São Paulo city (18.5%). Concerning anxiety the rates found were slightly lower than those in specific literature but higher than those in literature for the population in general (8% to 18%) and in city São Paulo (16.8%). These indices indicate that the school of medicine may play a role as a predisposing and/or triggering factor in some students. The results suggest that more attention should be directed to 5th year students, who are beginning the internship period.

Incorporation of antimicrobial peptides on functionalized cotton gauzes for medical applications

A large group of low molecular weight natural compounds that exhibit antimicrobial activity has been isolated from animals and plants during the past two decades. Among them, peptides are the most widespread resulting in a new generation of antimicrobial agents with higher specific activity. In the present study we have developed a new strategy to obtain antimicrobial wound-dressings based on the incorporation of antimicrobial peptides into polyelectrolyte multilayer films built by the alternate deposition of polycation (chitosan) and polyanion (alginic acid sodium salt) over cotton gauzes. Energy dispersive X ray microanalysis technique was used to determine if antimicrobial peptides penetrated within the films. FTIR analysis was performed to assess the chemical linkages, and antimicrobial assays were performed with two strains: Staphylococcus aureus (Gram-positive bacterium) and Klebsiella pneumonia (Gram-negative bacterium). Results showed that all antimicrobial peptides used in this work have provided a higher antimicrobial effect (in the range of 4 log–6 log reduction) for both microorganisms, in comparison with the controls, and are non-cytotoxic to normal human dermal fibroblasts at the concentrations tested.

Reversibility of ventricular dysfunction: clinical experience in a medical office

OBJECTIVE - To describe clinical observations of marked improvement in ventricular dysfunction in a medical office environment under circumstances differing from those in study protocols and multicenter studies performed in hospital or with outpatient cohorts. METHODS - Eleven cardiac failure patients with marked ventricular dysfunction receiving treatment at a doctors office between 1994 and 1999 were studied. Their ages ranged from 20 and 66 years (mean 39.42±14.05 years); 7 patients were men, 4 were women. Cardiopathic etiologies were arterial hypertension in 5 patients, peripartum cardiomyopathy in 2, nondefined myocarditis in 2, and alcoholic cardiomyopathy in 4. Initial echocardiograms revealed left ventricular dilatation (average diastolic diameter, 69.45±8.15mm), reduced left ventricular ejection fraction (0.38±0.08) and left atrial dilatation (43.36±5.16mm). The therapeutic approach followed consisted of patient orientation, elimination of etiological or causal factors of cardiac failure, and prescription of digitalis, diuretics, and angiotensinconverting enzyme inhibitors. RESULTS - Following treatment, left ventricular ejection fraction changed to 0.63±0.09; left ventricular diameters changed to 57.18±8.13mm, and left atrium diameters changed to 37.27±8.05mm. Maximum improvement was noted after 16.9±8.63 (6 to 36) months. CONCLUSION - Patients with serious cardiac failure and ventricular dysfunction caused by hypertension, alcoholism, or myocarditis can experience marked improvement in ventricular dysfunction after undergoing appropriate therapy within the venue of the doctor's office.