Design, fabrication and characterization of resonant waveguide grating based optical biosensors

The absence of rapid, low cost and highly sensitive biodetection platform has hindered the implementation of next generation cheap and early stage clinical or home based point-of-care diagnostics. Label-free optical biosensing with high sensitivity, throughput, compactness, and low cost, plays an important role to resolve these diagnostic challenges and pushes the detection limit down to single molecule. Optical nanostructures, specifically the resonant waveguide grating (RWG) and nano-ribbon cavity based biodetection are promising in this context. The main element of this dissertation is design, fabrication and characterization of RWG sensors for different spectral regions (e.g. visible, near infrared) for use in label-free optical biosensing and also to explore different RWG parameters to maximize sensitivity and increase detection accuracy. Design and fabrication of the waveguide embedded resonant nano-cavity are also studied. Multi-parametric analyses were done using customized optical simulator to understand the operational principle of these sensors and more important the relationship between the physical design parameters and sensor sensitivities. Silicon nitride (SixNy) is a useful waveguide material because of its wide transparency across the whole infrared, visible and part of UV spectrum, and comparatively higher refractive index than glass substrate. SixNy based RWGs on glass substrate are designed and fabricated applying both electron beam lithography and low cost nano-imprint lithography techniques. A Chromium hard mask aided nano-fabrication technique is developed for making very high aspect ratio optical nano-structure on glass substrate. An aspect ratio of 10 for very narrow (~60 nm wide) grating lines is achieved which is the highest presented so far. The fabricated RWG sensors are characterized for both bulk (183.3 nm/RIU) and surface sensitivity (0.21nm/nm-layer), and then used for successful detection of Immunoglobulin-G (IgG) antibodies and antigen (~1μg/ml) both in buffer and serum. Widely used optical biosensors like surface plasmon resonance and optical microcavities are limited in the separation of bulk response from the surface binding events which is crucial for ultralow biosensing application with thermal or other perturbations. A RWG based dual resonance approach is proposed and verified by controlled experiments for separating the response of bulk and surface sensitivity. The dual resonance approach gives sensitivity ratio of 9.4 whereas the competitive polarization based approach can offer only 2.5. The improved performance of the dual resonance approach would help reducing probability of false reading in precise bio-assay experiments where thermal variations are probable like portable diagnostics.

Attitudes and Knowledge Concerning Corneal Donation in a Population-Based Sample of Urban Chinese Adults.

PURPOSE: To better understand knowledge and attitudes concerning corneal donation among Chinese adults.
METHODS: Randomly selected residents in predetermined age strata 20 to 60+ years completed home-based questionnaires in each of 12 randomly chosen communities in Guangzhou, southern China.
RESULTS: Among 1217 selected persons, 430 (35.3%) completed the questionnaires (mean age 40.4 yrs, 57.9% female). Refusers were older (44.8 yrs, P < 0.001), but sex did not differ (52.2% female, P = 0.07). Among participants, 175 (40.7%) were willing to donate their corneas (WTD). Differences between WTD and not WTD included donation knowledge score (range, 1-12) [WTD (SD) 6.91 ± 2.21, not WTD 5.62 ± 2.43, P < 0.001]; having discussed donation (WTD 26.3%, not WTD 8.63%, P < 0.001); viewing donation as unpopular (WTD 88.0%, not WTD 96.5%, P = 0.001); and feeling donation "damages the body" (WTD 15.4%, not WTD 25.7%, P = 0.013). Associated significantly with WTD in multiple regression models were higher knowledge score [odds ratio (OR) = 1.18, 95% confidence interval (CI), 1.04-1.32, P = 0.008]; not feeling donation "damages the body" (OR = 1.91, 95% CI, 1.07-3.43, P = 0.030); and willingness to discuss donation (OR = 10.6, 95% CI, 3.35-33.9, P < 0.001). WTD did not differ by age (>60 yrs: 22/51, 43.1%; ≤60 yrs: 153/379, 40.4%, P = 0.706). Assuming all those refusing the survey would not donate, 14.4% (175/1217) were WTD for themselves, though only 7.1% (86/1217) would do so on behalf of a family member if they did not know the deceased's preference.
CONCLUSIONS: Interventions to increase knowledge and promote discussions about donation, and policies allowing widespread expression of donation preference, are needed in this setting.

Non-contact Pressure-based Sleep/Wake Discrimination

Poor sleep is increasingly being recognised as an important prognostic parameter of health. For those with suspected sleep disorders, patients are referred to sleep clinics which guide treatment. However, sleep clinics are not always a viable option due to their high cost, a lack of experienced practitioners, lengthy waiting lists and an unrepresentative sleeping environment. A home-based non-contact sleep/wake monitoring system may be used as a guide for treatment potentially stratifying patients by clinical need or highlighting longitudinal changes in sleep and nocturnal patterns. This paper presents the evaluation of an under-mattress sleep monitoring system for non-contact sleep/wake discrimination. A large dataset of sensor data with concomitant sleep/wake state was collected from both younger and older adults participating in a circadian sleep study. A thorough training/testing/validation procedure was configured and optimised feature extraction and sleep/wake discrimination algorithms evaluated both within and across the two cohorts. An accuracy, sensitivity and specificity of 74.3%, 95.5%, and 53.2% is reported over all subjects using an external validation
dataset (71.9%, 87.9% and 56%, and 77.5%, 98% and 57% is reported for younger and older subjects respectively). These results compare favourably with similar research, however this system provides an ambient alternative suitable for long term continuous sleep monitoring, particularly amongst vulnerable populations.

Evaluating the efficiency of community-based HIV testing and counseling strategies in sub-Saharan Africa

Thesis (Ph.D.)--University of Washington, 2016-08

Dimensões ludicas da memoria-trabalho

Universidade Estadual de Campinas . Faculdade de Educação Física

Association of dental enamel lead levels with risk factors for environmental exposure

OBJECTIVE: To analyze household risk factors associated with high lead levels in surface dental enamel. METHODS: A cross-sectional study was conducted with 160 Brazilian adolescents aged 14-18 years living in poor neighborhoods in the city of Bauru, southeastern Brazil, from August to December 2008. Body lead concentrations were assessed in surface dental enamel acid-etch microbiopsies. Dental enamel lead levels were measured by graphite furnace atomic absorption spectrometry and phosphorus levels were measured by inductively coupled plasma optical emission spectrometry. The parents answered a questionnaire about their children's potential early (05 years old) exposure to well-known lead sources. Logistic regression was used to identify associations between dental enamel lead levels and each environmental risk factor studied. Social and familial covariables were included in the models. RESULTS: The results suggest that the adolescents studied were exposed to lead sources during their first years of life. Risk factors associated with high dental enamel lead levels were living in or close to a contaminated area (OR = 4.49; 95% CI: 1.69;11.97); and member of the household worked in the manufacturing of paints, paint pigments, ceramics or batteries (OR = 3.43; 95% CI: 1.31;9.00). Home-based use of lead-glazed ceramics, low-quality pirated toys, anticorrosive paint on gates and/or sale of used car batteries (OR = 1.31; 95% CI: 0.56;3.03) and smoking (OR = 1.66; 95% CI: 0.52;5.28) were not found to be associated with high dental enamel lead levels. CONCLUSIONS: Surface dental enamel can be used as a marker of past environmental exposure to lead and lead concentrations detected are associated to well-known sources of lead contamination.

Long-Term Prospective, Randomized, Controlled Study Using Repetitive Education at Six-Month Intervals and Monitoring for Adherence in Heart Failure Outpatients The REMADHE Trial

Background-The effectiveness of heart failure disease management proarams in patients under cardiologists` care over long-term follow-up is not established. Methods and Results-We investigated the effects of a disease management program with repetitive education and telephone monitoring on primary (combined death or unplanned first hospitalization and quality-of-life changes) and secondary end points (hospitalization, death, and adherence). The REMADHE [Repetitive Education and Monitoring for ADherence for Heart Failure] trial is a long-term randomized, prospective, parallel trial designed to compare intervention with control. One hundred seventeen patients were randomized to usual care, and 233 to additional intervention. The mean follow-up was 2.47 +/- 1.75 years, with 54% adherence to the program. In the intervention group, the primary end point composite of death or unplanned hospitalization was reduced (hazard ratio, 0.64; confidence interval, 0.43 to 0.88; P=0.008), driven by reduction in hospitalization. The quality-of-life questionnaire score improved only in the intervention group (P<0.003). Mortality was similar in both groups. Number of hospitalizations (1.3 +/- 1.7 versus 0.8 +/- 1.3, P<0.0001), total hospital days during the follow-up (19.9 +/- 51 versus 11.1 +/- 24 days, P<0.0001), and the need for emergency visits (4.5 +/- 10.6 versus 1.6 +/- 2.4, P<0.0001) were lower in the intervention group. Beneficial effects were homogeneous for sex, race, diabetes and no diabetes, age, functional class, and etiology. Conclusions-For a longer follow-up period than in previous studies, this heart failure disease management program model of patients under the supervision of a cardiologist is associated with a reduction in unplanned hospitalization, a reduction of total hospital days, and a reduced need for emergency care, as well as improved quality of life, despite modest program adherence over time. (Circ Heart Fail. 2008;1:115-124.)

A 12-month randomized controlled trial of balance training in elderly women with ostebporosis: Improvement of quality of life

Objective: Physical and psychological incapacity, including fear of falling is related to decreased satisfaction with life in osteoporosis (OP). The impact of a balance exercise program on improving the quality of life is not well established. We have, therefore, investigated the effect of 12-month Balance Training Program in quality of life, functional balance and falls in elderly OP women. Methods: Sixty consecutive women with senile OP were randomized into a Balance Training Group (BT) of 30 patients and no intervention control group (CG) of 30 patients. The BT program included techniques to improve balance over a period of 12 months (1 h exercise session/week and home-based exercises). The quality of life was evaluated before and at the end of the trial using the Osteoporosis Assessment Questionnaire (OPAQ), functional balance was evaluated by Berg Balance Scale (BBS). Falls in the preceding year were noted and compared to the period of study. Results: The comparison of OPAQ variations (INITIAL-FINAL) revealed a significant improvement in quality of life in all parameters for BT compared to CG: well-being (1.61 +/- 1.44 vs. -1.46 +/- 1.32, p < 0001), physical function (1.30 +/- 1.33 vs. -0.36 +/- 0.82, p < 0.001), psychological status (1.58 +/- 1.36 vs. -1.02 +/- 0.83, p < 0.001), symptoms (2.76 +/- 1.96 vs. -0.63 +/- 0.87, p < 0.001), social interaction (1.01 +/- 1.51 vs. 0.35 +/- 1.08, p < 0.001). Of note, this overall benefit was paralleled by an improvement of BBS (-5.5 +/- 5.67 vs. +0.5 +/- 4.88 p < 0.001) and a reduction of falls in 50% in BT group vs. 26.6% for the CG (RR: 1.88, p < 0.025). Conclusion: The long-term Balance Training Program of OP women provides a striking overall health quality of life improvement in parallel with improving functional balance and reduced falls. (C) 2010 Elsevier Ireland Ltd. All rights reserved.

Rotavirus morbidity and mortality in children in Brazil

Objective. To study the epidemiology of rotavirus and estimate rotavirus- associated morbidity and mortality in children <= 5 years of age in Brazil in 2004 before introducing the rotavirus vaccine in Brazil`s National Immunization Program ( Programa Nacional de Imunizacoes, PNI). Methods. To estimate rotavirus morbidity, published studies ( 1999 - 2006) addressing incidence of acute diarrhea among children <= 5 years of age and frequency of rotavirus infection among children with diarrhea in Brazil were reviewed. Diarrhea episodes were divided into three categories of severity by level of care: mild cases requiring only home- based care; moderate cases requiring a visit to an outpatient healthcare facility; and severe cases requiring hospitalization. To estimate rotavirus mortality, information on the number of registered deaths from diarrhea in children <= 5 years of age was obtained from the Mortality Information System ( Sistema de Informacao, sobre Mortalidade, SIM) of Brazil`s public healthcare system ( Sistema Unico de Sa de, SUS) and the proportion of deaths due to rotavirus was calculated. Results. Rotavirus infections were estimated to cause 3 525 053 episodes of diarrhea, 655 853 visits to outpatient healthcare facilities, 92 453 hospitalizations, and 850 deaths of children <= 5 years of age each year in Brazil. Conclusion. Rotavirus infections are an important cause of child morbidity and mortality in Brazil.

Rehabilitation outcomes following percutaneous coronary interventions (PCI)

This prospective study evaluated the effect of an individualized, comprehensive, home-based cardiac rehabilitation program combining exercise training with risk factor modification and psychosocial counseling on risk factors, psychological wellbeing, functional capacity, and work resumption in 99 post-percutaneous coronary interventions (PCI) patients randomized to control (standard care plus telephone follow-up, n = 49) or intervention (individualized, comprehensive, home-based cardiac rehabilitation, n = 50) groups. Data were collected at time 1 (T-1) during hospital admission, time 2 (T-2) approximately 2 months post-PCI, and time 3 (T-3) approximately 12 months post-PCI. Results suggest that the allocation to an individualized, comprehensive, home-based cardiac rehabilitation program provided more advantageous outcomes. At both follow-ups, the intervention group showed within-group improvement in serum cholesterol levels (P < 0.02; P < 0.01) and exercise participation (P < 0.001; P < 0.001) with differences in exercise participation favoring the intervention group (P < 0.01) at T-2 Repeated measures ANOVA showed significant improvements over time in body mass index (BMI) (P < 0.01), psychological well-being (P < 0.001), and functional capacity (P < 0.001) for both groups. More patients in the intervention group had returned to work at T-2 (P < 0.001) and did so more quickly (P < 0.01). These findings suggest that an individualized, comprehensive, home-based cardiac rehabilitation program improves risk factor profiles and work resumption patterns for patients following PCI. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.

Pediculus humanus capitis infestations in the community: A pilot study into transmission, treatment and factors affecting control

Head lice (Pediculus humanus capitis) infestations affect schoolchildren worldwide, creating social, economic and health consequences for families. Problems with self-detection, chronic infestations and classroom transmission are compounded by increasing resistance of the lice to pediculicides. Public health strategies are based on limited research and little is known about transmission dynamics. Mismanagement and transmission in the general community are blamed for control failure. The purpose of this study was to explore community head-lice experience in Brisbane, Australia, and to identify critical factors underlying control failure. A home-based pilot survey used physical examination to verify transmission and treatment patterns which were self-reported by a group of trace-contact families in addition to other unconnected participants. The survey was enlarged to further compare therapy outcomes and suspected risk factors. The findings reinforce those of previous studies - that children attending school and early childhood centres, and subsequently their families, are most at risk of contracting pediculosis capitis, and some may carry lice for years. First-line (pediculicidal) treatment and even additional physical methods of hand-picking and fine-toothed combing usually fail to eradicate lice quickly and completely (overall cure-rate 39 per cent, n = 84 cases). Failures were linked to hair characteristics. Public education alone may not control pediculosis. Accurate diagnosis requires considerable experience; a strong case exists for returning to institutional surveillance.

Muscle strength and function before and after anterior cruciate ligament reconstruction using semitendonosus and gracilis

This study assessed the quadriceps and hamstring strength before and 6 months after anterior cruciate ligament (ACL) reconstructive surgery using the hamstrings and related the findings to functional performance. Six months after surgery is a critical time for assessment as this is when players are returning to sport. Maximum isokinetic strength of 31 patients with complete unilateral ACL ruptures was measured at speeds of 60 degrees and 120 degrees per second. Functional assessment included the single hop, the triple hop, the shuttle run, side-step and carioca tests. All patients underwent a controlled quadriceps emphasized home-based physiotherapy program both before and after surgery. Results show that before surgery there was a 7.3% quadriceps strength deficit at 60 degrees per second compared to the uninjured leg but no hamstring strength deficit. After surgery there was a statistically significant but relatively small loss of muscle strength. The quadriceps strength deficit had increased to 12% and there was a 10% hamstring deficit. Post-operatively there was an 11% and 6.3% improvement in the hop tests, a 9% (P < 0.01) improvement in the shuttle run, a 15% (P < 0.001) improvement in the side step and a 24% (P < 0.001) improvement in the carioca tests (P < 0.001) despite the loss of muscle strength. (C) 2001 Elsevier Science B.V. All rights reserved.

Efeitos de um programa de exercício na aptidão física pós transplante hepático: o caso da polineuropatia amiloidótica familiar nas suas componentes composição corporal, capacidade funcional e função neuromuscular

Introdução – A Polineuropatia Amiloidotica Familiar (PAF) é uma amiloidose sistémica heredo-degenerativa e autossómica dominante, e cuja manifestação predominante é a polineuropatia mista sensitiva motora e autonómica. Aos sintomas motores e sensitivos associam-se também alterações cardíacas, renais, urinárias, genitais e digestivas que se traduzirão em incapacidade funcional progressiva. Esta doença endémica de Portugal apresenta o seu início em média depois dos 20 anos com progressão para a morte em cerca de 10 anos. O tratamento etiopatogénico desta doença, com reconhecida eficácia, passa ainda pelo transplante hepático que apesar de tudo é efectuado já numa fase sintomática da doença e ao qual se encontra associada medicação com efeitos negativos para o metabolismo muscular e consequentemente para a capacidade de produção de força. Tanto a progressão da PAF como o próprio transplante resultam em limitações funcionais que podem ser melhoradas através do exercício físico. Do nosso conhecimento não existem estudos sobre a aptidão física destes pacientes submetidos a transplante hepático nem sobre os efeitos de um programa de exercício físico. Objectivo: Verificar o efeito de um programa de exercício físico combinado na aptidão física de indivíduos portadores de PAF submetidos a transplante hepático há menos de 12 meses. Adicionalmente, analisar de que modo algumas componentes da aptidão física (composição corporal, força muscular e capacidade funcional) seriam ou não e em que medida, diferentes da população saudável. Material e métodos: Trinta e nove pacientes PAF transplantados (4.3±3.3 meses pós transplante foram avaliados quanto à sua composição corporal (DEXA), força de preensão (dinamometro de preensão E-Link), força isométrica do quadricipete (dinamometria isocinética-Biodex) e capacidade funcional (teste 6 minutos de marcha - 6MWT e capacidade para a marcha – 6MWT×peso). Os níveis de actividade física e de qualidade de vida percebida foram avaliados respectivamente através dos questionários Seven Days Physical Activity Recall (7-PAR) e Medical Outcome Study item shortform Health Survey (SF-36Ò). Os pacientes foram alocados em três grupos: grupo de controlo(GC) com 16 pacientes (13H e 3M; 33±9 anos, IMC 22.6±3.3 kg.m-2) sem programa de exercício; grupo de exercício supervisionado (GES) com 8 pacientes (5H e 3M; 34±±7 years; IMC 20.4±4.5 kg.m-2) submetidos a um programa de exercício físico combinado trissemanal com a duração de 24 semanas e um grupo de exercício físico domiciliário ou home-based (GHB) com 15 pacientes (4H e 11M; 35±5 anos; IMC 22.3±4.3 kg.m-2) que fizeram exercício físico em casa durante 24 semanas. Para comparar variáveis da aptidão física entre pacientes PAF transplantados e indivíduos aparentemente saudáveis, submetemos 48 indivíduos PAF transplantados há menos de 12 meses e 24 indivíduos saudáveis não activos, ao mesmo protocolo de avaliação (composição corporal, força muscular e capacidade funcional). Resultados: O programa de exercício influenciou positivamente a composição corporal (peso, IMC, massa magra total e regional, massa muscular esquelética total e T-score do fémur proximal), o risco de incapacidade física, a capacidade para a marcha e a força de preensão da mão direita, mas não influenciou a percepção de qualidade de vida dos pacientes. A distância percorrida aumentou de forma clinicamente significativa apenas no grupo GES. Os pacientes PAF transplantados apresentaram valores inferiores aos indivíduos saudáveis na composição corporal (peso, IMC, massa óssea, massa gorda, massa magra e massa muscular) força muscular e capacidade funcional. Conclusões: O programa de exercício físico melhorou a composição corporal, capacidade funcional e força muscular e aumentou o peso corporal e o IMC nos doentes PAF. Esta melhoria foi maior no grupo GES do que no grupo GHB em todas as variáveis analisadas.

Caracterização da prática do fisioterapeuta na sua intervenção em crianças até um ano de idade com torcicolo muscular congénito

Mestrado em Fisioterapia.