Estudo da resistência à corrosão em fluido corpóreo e caracterização da liga biomédica Ti-40Nb

Orientador: Profª. Drª. Cláudia Eliana Bruno MarinoCoorientador: Profª. Drª. Neide Kazue KuromotoDissertação (mestrado) - Universidade Federal do Paraná, Setor de Tecnologia, Programa de Pós-Graduação em Engenharia e Ciência dos Materiais - PIPE. Defesa: Curitiba, 02/12/2015Inclui referências : f. 101-114Área de concentração: Engenharia e ciência de materiaisResumo: As ligas de Titânio-Nióbio são bastante pesquisadas para aplicações biomédicas por apresentarem alta biocompatibilidade e excelentes propriedades mecânicas para aplicações biomédicas. Estudos em ligas de Ti-Nb com variação no teor de Nióbio (~5-35 m/m%) mostraram uma tendência ao aumento da dureza e diminuição do módulo de elasticidade ao se aumentar o teor de Nióbio nas ligas. No que diz respeito à estabilidade físico-química, as ligas Ti-Nb costumam manter as propriedades do metal Titânio, o qual é altamente resistente à corrosão em meios agressivos devido ao óxido estável espontâneo (TiO2) formado na superfície. Assim, o objetivo deste trabalho foi avaliar a resistência à corrosão e caracterização superficial dos biomateriais Ti e Nb comercialmente puros e da liga metalúrgica Ti-40Nb em solução de sangue artificial. A microestrutura dos biomateriais foi analisada utilizando-se microscópio óptico e pela técnica de difração de raios X. Nanoidentação instrumentada e dureza Vickers foram utilizadas para avaliar as propriedades mecânicas. Para se estudar a estabilidade termodinâmica dos biomateriais foi utilizada a técnica de potencial de circuito aberto e a resistência à corrosão por medidas potenciodinâmicas e de espectroscopia de impedância eletroquímica. As imagens de microscopia óptica e os difratogramas de raios X mostraram a presença das fases ?'' (ortorrômbica), ? (cubica de corpo centrado) e ? (hexagonal) na liga Ti-40Nb. Já os resultados eletroquímicos indicaram que a liga Ti-40Nb possui resistência à corrosão elevada, boa estabilidade termodinâmica sendo o potencial de circuito aberto em torno de -485 mV (Ti: -131 mV). A liga se manteve eletroquimicamente estável em condições potenciodinâmicas com potenciais inicial e final de -1,0 a +2,0 V(SCE), respectivamente, sob baixas densidades de corrente (~?A/cm2) e sem apresentar histerese, o que caracteriza um processo de dissolução/corrosão. Quanto às propriedades mecânicas, a liga apresentou microdureza em torno de 157 HV (Ti: 177 HV) e módulo de elasticidade de ~78 GPa (Ti: 110 GPa). Os resultados obtidos mostraram que esta liga específica tem potencial para ser usada em aplicações biomédicasAbstract: The Ti-Nb alloys are widely studied for biomedical applications due to their high biocompatibility and excellent mechanical properties for biomedical applications. Studies of Ti-Nb alloy with variation in the Nb content (~5-35 m/m.%) demonstrated a tendency of increase of hardness and decrease of elastic modulus with increasing Nb content. Regarding the physical-chemical stability, Ti-Nb alloy maintains the properties of Ti metal which is highly resistant to corrosion in aggressive media due to a spontaneous stable oxide (TiO2) formed on the surface. The objective of this study was the analysis of corrosion resistance and surface characterization of commercially pure Ti biomaterial and metallic Ti-40Nb alloy in artificial blood. The microstructures of biomaterials were analysed using optical microscope and by X-ray diffraction technique. Instrumented nanoindentation and Vickers hardness were used to evaluate the mechanical properties. To study the thermodynamic stability it was used the open circuit potential technique and the corrosion resistance by potentiodynamic measure and electrochemical impedance spectroscopy. The optical microscopy images and X-ray spectra showed the presence of ƒ¿ff (orthorhombic), ƒÀ (body centered cubic) and ƒÖ (hexagonal) phases in the Ti-40Nb alloy. The electrochemical results indicated that the Ti-40Nb alloy has high corrosion resistance and good thermodynamic stability with open circuit potential of around -485 mV (Ti: -131 mV) and the alloy remained electrochemically stable in potentiodynamic conditions with initial and final potentials of -1.0 V to +2.0 Vsce, respectively in low current densities (~ƒÊA/cm2) with absence of hysteresis, wich characterize a corrosion/dissolution process. About the mechanical properties, the Ti-Nb alloy hardness was around 157 HV (Ti: 176HV) and the elastic modulus ~78 GPa (Ti: 100 GPa). The results obtained showed that this specific alloy has potential to be used in biomedical applications

Clima organizacional como factor clave para optimizar el rendimiento de los empleados en la dirección Departamental de Educación Santa Ana MINED

En la era en la que se vive, el capital humano protagoniza un papel fundamental en cada una de las instituciones en las que se desempeña, y uno de los temas referidos al capital humano que es de gran interés para cada una de las organizaciones es el Clima Organizacional. Un buen Clima Organizacional en los lugares de trabajo, es determinante para el buen funcionamiento de las instituciones u organizacione

POR UNA CULTURA DE PAZ: UNA MIRADA DESDE LAS CIENCIAS DE LA CONDUCTA

En
 virtud
 de
 lo
 anterior,
 los
 estudiosos
 de
 las
 ciencias
 de
 la
 conducta
 
de
 la
 Universidad
Autónoma 
del
 Estado 
de 
México,

ante 
la
persistencia
 y 
proliferación
 de
 estos 
hechos
 en
 diversas
 partes
 del
Mundo
 y
 de
 nuestro 
país 
en 
particular, se
 convocó
 a
 los
 estudiosos
 interesados
 y
 a
 la
 sociedad
 en
 general
 a
 presentar
 trabajos
 para
 analizar,
 debatir
 y
 proponer
 estrategias
 de
 acción
 y
 dirección,
 que
 fortalezcan
 una
 convivencia y bienestar con sentido humanista para una cultura de paz. El
 presente
 texto
 es
 producto
 de 
esta convocatoria 
que
 recoge 
los
trabajos 
de 

los
 interesados 
en 
la
 temática,

 de
 diferentes 
países
(España,
Argentina,
Cuba,
Brasil,
Costa
 Rica
 y
 México)
 retomando
 con
 ello
 sus
 experiencias
 relativas
 al
 estudio,
 análisis,
 comprensión
 e
 instrumentación
 de
 la
 cultura
 de
 paz
 en
 los
 distintos
 ámbitos
 institucionales
 en
 los
 que
 participan:
 educativo,
 salud,
 penitenciario,
 social,
laboral,
familia,
alimentario,
psicológico,
por 
mencionar 
algunos.
 El
 presente
 libro,
 propicia
 un
 espacio
 de
 reflexión,
 diálogo
 y
 posicionamiento
 de
 las 
ciencias 
de 
la 
conducta
 para 
la 
apropiación,
análisis,
debate
 y 
propuestas 
que
 fortalezcan 
una
 cultura
 de 
paz
 a
través
 de 
la
 convivencia 
y
 el 
bienestar
 social 
con
 sentido 
humanista.
El
 sistema 
económico
 neoliberal
 y 
el 
proceso
 de 
globalización 
han
 contribuido
al
 logro
 de
 avances
 significativos
 en
 la
 ciencia
 y
 la
 tecnología,
 pero
 también
 han
 propiciado
 la
 polarización
 de
 las
 sociedades
 lo
 que
 ha
 impactado
 de
 manera
 negativa
 a
 la
 sociedad
 en
 su
 conjunto,
 pero
 en
 mayor
 medida
 a
 los grupos
 vulnerables. Dicha
 polarización
 ha
 traído
 consigo
 un
 desarrollo
 desigual
 del
 mundo
 que
 se
 expresa
 de
 diferentes
 maneras
 tanto
 en
 países
 desarrollados
 como
 en
 los
 llamados
 del
 tercer
 mundo,
 en
 donde
 no
 están
 satisfechas
 las
 necesidades
 humanas 
elementales
 de
 todos 
los
sectores 
de 
la 
población,
siempre 
falta 
algo. 
Si 
a
 esto 
le
 sumamos 
los
conflictos
 internacionales por
 diferentes
 motivos
 que
 enfrentan
 algunas
 naciones,
 una
 insuficiente
 cobertura
 educativa
 y
 de
 salud,

 desempleo
 y
 pobreza 
extrema,
 entre 
otras
 cosas; 
estamos
 frente
 a
retos 
de
 gran
 envergadura
 para
 los
 gobiernos,
 para
 los
 estudiosos
 y
 para
 la
 sociedad
 civil
 en
 general. Uno 
de 
los
 intentos
 para
 frenar 
y prevenir 
la
 agudización
 de 
estas 
problemáticas
 es
 la
 cultura 
de 
paz,
cuyo
 estudio
y propuestas 
han 
ido 
avanzando 
en 
diferentes
 sentidos 
y 
de 
manera 
favorable,
el 
tema 
está 
presente 
en 
diferentes 
Organismos
 Internacionales
 como
 la
 ONU,
 la
 UNESCO,
 la
 OCDE,
 El
 Banco
 Mundial,
 entre
 otros.
 Pero
 falta 
mucho 
por 
hacer.Universidad Autónoma del Estado de Méxic

una mirada desde las Ciencias de la Conducta

Este libro es el resultado de los trabajos presentados en el 1er Congreso Internacional "Convivencia y bienestar con sentido humanista para una cultura de paz"

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Estimation of Spatio-Temporal Parameters of Gait and Posture of Visually Impaired People Using Wearable Sensors

In rehabilitating orientation and mobility (O&M) for visually impaired people (VIP), the measurement of spatio-temporal gait and postural parameters is of specific interest for rehabilitators to assess performance and improvements in independent mobility. In the current practice of rehabilitation worldwide, this assessment is carried out in people with estimates made visually. The objective of this research was to propose a simple architecture based on the use of wearable inertial sensors for quantitative estimation of distance traveled, step detection, gait velocity, step length and postural stability. These parameters were calculated using absolute orientation angles. Two different sensing architectures were tested for gait according to a selected biomechanical model. The validation tests included five different walking tasks. There were nine visually impaired volunteers in real-time acquisitions, where the volunteers walked indoor and outdoor distances at different gait velocities in their residences. The ground truth gait characteristics of the volunteers in five walking tasks and an assessment of the natural posture during the walking tasks are also presented in this article. One of the proposed methods was selected for presenting the lowest absolute error of the calculated parameters in all of the traveling experimentations: 45 walking tasks between 7 and 45 m representing a total of 1039 m walked and 2068 steps; the step length measurement was 4.6 ± 6.7 cm with a mean of 56 cm (11.59 Std) and 1.5 ± 1.6 relative error in step count, which compromised the distance traveled and gait velocity measurements, presenting an absolute error of 1.78 ± 1.80 m and 7.1 ± 7.2 cm/s, respectively. The results suggest that the proposed method and its architecture could be used as a tool for assistive technology designed for O&M training to assess gait parameters and/or navigation, and that a sensor placed in the dorsal area is sufficient to detect noticeable postural changes that compromise heading, inclinations and balancing in walking tasks

Development of a motion measurement system of a long cane for Visually Impaired People in rehabilitation

The rehabilitation of a blind person is a systematic process where the person is dotted with tools that allow them to deal with the impairment, including the correct use of the long cane for navigation in the Orientation and Mobility training. In this process, technology as inertial measurement sensors could be included to track the motion of the cane in order to evaluate the correct use. One sensor added to the cane can provide valuable information about orientation, position, velocity and trajectory of the tip. In this research, a system was developed by adding a BNO055 inertial sensor to the lower part of the long cane in order to analyze the output with the help of Arduino, Simulink and MATLAB. A method was developed to obtain qualitative information about the movements of the long cane during the training of mobility and the reliability was tested. The tests were carried out with a real cane, in isolated situations and a controlled environment, corresponding to real techniques that will be trained during rehabilitation. The experimental results indicate that the parameters obtained in the orientation test and in the short displacement test presented a standard error ~1% in both cases and an accuracy of 98 and 97% respectively. However, for the sliding test for simulation of the diagonal technique, the difference in the value of the mean obtained with respect to the real value was 39%. Despite presenting reproducibility in tests with low standard errors, to obtain precise displacement or position value, a more complex census is required, or a new method should be developed for evaluation. The system requires further development in order to be used in the assistant program for the rehabilitation process