Study of the drying kinetics for apples in a convective drier

In the present work a convective drier was used to dehydrate apple slices up to a moisture content of less than 2 % (wet basis), so as to obtain a crunchy apple snack. Two commercial varieties were tested, namely Golden and Smith. The drier was operated at different temperatures, 30, 40 50 and 60 ºC, and the moisture content of the product was calculated based on the mass, which was registered by means of a data logger, throughout the whole trial. The kinetic data was then treated and fitted to different thin layer models frequently cited in literature, which were: Page, Henderson and Pabis, Logarithmic and Vega-Lemus. Others were also tested, but convergence was not achieved. For the fitting software SigmaPlot V8.0 (SPSS, Inc.) was used, and to evaluate the quality of the estimations the correlation coefficient (R) and the standard error of the estimate (SEE) were determined From the models tested it was possible to see that the Vega-Lemus was the worst to describe the drying kinetic in the present case, on the other hand, the best model was the Page. Also the Fick’s equation for diffusion was used to estimate the diffusivities at different temperatures, and from those to estimate the activation energy for moisture diffusion, which was found to be 35 kJ/mol for the drying of apples from Golden variety and 33 kJ/mol for the Smith variety

Study of chemical and physical properties of apples dried in a convective drier.

The present study evaluates the effects of drying on apple slices from two varieties, Golden Delicious and Granny Smith, which were analyzed in terms of physical and chemical properties. The tests involved the determination of moisture, acidity, soluble solids, colour and texture. Trials were performed in a convective hot air dryer for different temperatures of 30, 40, 50 and 60 ° C. The results showed that the final moisture of the two varieties of apples was around 3 % (wet basis). With regards to acidity, the variety Granny Smith was found to be more acid than the Golden Delicious. The soluble solids are present, in general, in greater amounts in the variety Granny Smith. As to the colour, this varied very considerably from the fresh apples to the dried ones. Apples of the variety Golden Delicious presented a higher intensity of yellow (b* > 0) and red (a* > 0). However, in comparison to the variety Granny Smith the Golden Delicious presents, in general, smaller total colour differences. The textural attributes evaluated were hardness, adhesiveness, elasticity, cohesiveness and chewiness. However, the results for adhesiveness were very close to zero showing that these products do not have adhesiveness, as it happens with other fruits. It was also found that the fresh apples have a much higher hardness, when compared to the dried samples. Elasticity, on the other hand, was kept approximately constant regardless of the variety or state. Cohesiveness was higher in the fresh apples, and for the dried ones was higher for variety Golden. Finally, chewiness was higher for the fresh apples in comparison to the dried ones, and was higher for Golden Delicious when compared with Granny Smith

Data-driven approach to optimum wavelength selection for diffuse optical imaging

The production of accurate and independent images of the changes in concentration of oxyhemoglobin and deoxyhemoglobin by diffuse optical imaging is heavily dependent on which wavelengths of near-infrared light are chosen to interrogate the target tissue. Although wavelengths can be selected by theoretical methods, in practice the accuracy of reconstructed images will be affected by wavelength-specific and system-specific factors such as laser source power and detector sensitivity. We describe the application of a data-driven approach to optimum wavelength selection for the second generation of University College London's multichannel, time-domain optical tomography system (MONSTIR II). By performing a functional activation experiment using 12 different wavelengths between 690 and 870 nm, we were able to identify the combinations of 2, 3, and 4 wavelengths which most accurately reproduced the results obtained using all 12 wavelengths via an imaging approach. Our results show that the set of 2, 3, and 4 wavelengths which produce the most accurate images of functional activation are [770, 810], [770, 790, 850], and [730, 770, 810, 850] respectively, but also that the system is relatively robust to wavelength selection within certain limits. Although these results are specific to MONSTIR II, the approach we developed can be applied to other multispectral near-infrared spectroscopy and optical imaging systems

Anatomical aspects of Mycobacterium tuberculosis–associated destructive cranial lesions

The authors report two cases of destructive cranial lesions associated with Mycobacterium tuberculosis–HIV coinfection in a male and female cadaver. Both cadavers were of African origin, from the Western Cape, South Africa. The authors present grossly abnormal tuberculosis–associated lesions of the anterior and middle cranial fossae, involving the ethmoid and sphenoid bones. Both individuals presented with tubercular intrasellar masses and obliteration of the paranasal sinuses. Current literature on cases such as these are extremely rare and others typically focus on lesions of the calvarium. Here we report on the gross anatomical findings as well as the relevant anatomical aspects of the probable aetiology. Both cases presented here hold interest for medical professionals in Africa and other geographic regions. It further illustrates the importance of understanding the venous drainage of the paranasal sinuses when considering the manifestation and treatment of extrapulmonary TB

Comparing the cost-effectiveness of two screening strategies for latent tuberculosis infection in Portugal

Introduction and objectives: Screening for latent tuberculosis infection (LTBI) in close contacts of infectious TB cases might include Tuberculin Skin Test (TST) and Interferon-Gamma Release Assays (IGRA), in combination or as single-tests. In Portugal, the screening strategy changed from TST followed by IGRA to IGRA-only testing in 2016. Our objective was to compare the cost-effectiveness of two-step TST/IGRA with the current IGRA-only screening strategy in immunocompetent individuals exposed to individuals with respiratory TB. Materials and methods: We reviewed clinical records of individuals exposed to infectious TB cases diagnosed in 2015 and 2016, in two TB outpatient centers in the district of Porto. We estimated medical, non-medical and indirect costs for each screening strategy, taking into account costs of tests and health care personnel, travel distance from place of residence to screening site and employment status. We calculated the incremental cost-effectiveness ratio (ICER) as the cost difference between the two screening strategies with the difference number of LTBI diagnosis as a measure of cost-effectiveness, assuming that treating LTBI is a cost-effective intervention. We also calculated adjusted odds-ratios to test the association between diagnosis of LTBI and screening strategy and estimated the total cost for averting a potential TB case. Results: We compared 499 contacts TST/IGRA screened with 547 IGRA-only. IGRA-only strategy yielded a higher screening effectiveness for diagnosing latent tuberculosis infection (aOR 2.12, 95%CI: 1.53 - 2.94). ICER was €106 per LTBI diagnosis, representing increased effectiveness with a slightly increased cost of IGRA-only screening strategy. Conclusions: Our data suggests that in Portugal LTBI screening with IGRA-only is more cost-effective than the two-step TST/IGRA testing strategy, preventing a higher number of cases of TB cases

Health Care, Hospitals and Racial Hygiene in German Colonial Windhoek (1890-1915)

The gradual progress of health care within Namibia (formerly known as German South-West Africa), coincided with the three major historic periods: colonial settlement, the Herero-Nama genocide (1904-1907), and the transition of administration of the colony after the First World War. Here the authors draw upon primary and secondary sources to provide insights on the development of hospitals, health care and racial hygiene in in the colony with specific reference to Windhoek. The aim here is to contribute towards the lacking historiography of the medical landscape of Windhoek. Health care during the period of German colonial rule was centralised and segregated, and this trend prevailed when South Africa undertook administration of the colony. The initial strategy under German rule was to increase the formal treatment facilities within Swakopmund and Windhoek during the 1890s. The early growth of health care and hospitals was chiefly aimed at the needs of the white Europeans and driven by principles of racial hygiene

Longer duration of obesity is associated with a reduction in urinary angiotensinogen in prepubertal children

Background: We aimed to study the impact of obesity on urinary excretion of angiotensinogen (U-AGT) in prepubertal children, focusing on the duration of obesity and gender. Also, we aimed to evaluate whether plasma angiotensinogen (P-AGT) and hydrogen peroxide (H2O2) play a role in the putative association. Methods: Cross-sectional evaluation of 305 children aged 8–9 years (160 normal weight, 86 overweight, and 59 obese). Anthropometric measurements and 24-h ambulatory blood pressure monitoring were performed. Angiotensinogen (AGT) was determined by a commercial enzyme-linked immunosorbent assay (ELISA) kit and H2O2 by a microplate fluorometric assay. Results: U-AGT and P-AGT levels were similar across body mass index (BMI) groups and between sexes. However, boys who were overweight/obese since the age of 4 years presented lower levels of U-AGT compared with those of normal weight at the same age. In children who were overweight/obese since the age of 4, urinary H2O2 decreased with P-AGT. Conclusions: A higher duration of obesity was associated with decreased U-AGT in boys, thus reflecting decreased intrarenal activity of the renin–angiotensin system. Also, children with a longer duration of obesity showed an inverse association between urinary H2O2 and P-AGT. Future studies should address whether these results reflect an early compensatory mechanism to limit obesity-triggered renal dysfunction.This project was supported by funds from Fundo Europeu de Desenvolvimento Regional (FEDER) from Programa Operacional Factores de Competitividade – COMPETE (FCOMP-01-0124-FEDER-028751), by national funds from the Portuguese Foundation for Science and Technology (FCT) (PTDC/DTP-PIC/0239/2012) and by Calouste Gulbenkian Foundation, that granted the study design and data collection and analysis. Liane Correia-Costa was supported by FCT (grant SFRH/SINTD/95898/2013), Teresa Sousa was supported by FCT and POPH/FSE (EC) (Ciência 2008 and SFRH/BPD/112005) and Franz Schaefer was supported by the ERA-EDTA Research Programme and the KfH Foundation for Preventive Medicine. The Epidemiology Research Unit (EPIUnit) is funded by FCT (UID/DTP/04750/2013)

Impact of physical activity on redox status and nitric oxide bioavailability in nonoverweight and overweight/obese prepubertal children

Nutritional status might contribute to variations induced by physical activity (PA) in redox status biomarkers. We investigated the influence of PA on redox status and nitric oxide (NO) production/metabolism biomarkers in nonoverweight and overweight/obese prepubertal children. We performed a cross-sectional evaluation of 313 children aged 8-9 years (163 nonoverweight, 150 overweight/obese) followed since birth in a cohort study (Generation XXI, Porto, Portugal). Plasma total antioxidant status (P-TAS), plasma and urinary isoprostanes (P-Isop, U-Isop), urinary hydrogen peroxide (U-H2O2), myeloperoxidase (MPO) and plasma and urinary nitrates and nitrites (P-NOx, U-NOx) were assessed, as well as their association with variables of reported PA quantification (categories of PA frequency (>1x/week and ≤1x/week)and continuous PA index (obtained by the sum of points)) in a questionnaire with increasing ranks from sedentary to vigorous activity levels. U-NOx was significantly higher in children who presented higher PA index scores and higher PA frequency. Separately by BMI classes, U-NOx was significantly higher only in nonoverweight children who practiced PA more frequently (p = 0.037). In overweight/obese children, but not in nonoverweight, P-TAS was higher among children with higher PA frequency (p = 0.007). Homeostasis model assessment index (HOMA-IR) was significantly lower in more active overweight/obese children, but no differences were observed in nonoverweight children. In the fully adjusted multivariate linear regression models for P-TAS, in the overweight/obese group, children with higher PA frequency presented higher P-TAS. In the U-NOx models, U-NOx significantly increased with PA index, only in nonoverweight children. Our results provide additional evidence in support of a protective effect of physical activity, in nonoverweight by increasing NO bioavailability and in overweight/obese children by enhancing systemic antioxidant capacity and insulin sensitivity. These results highlight the importance of engaging in regular physical exercise, particularly among overweight/obese children, in which a positive association between oxidant status and cardiometabolic risk markers has been described.This project was supported by FEDER funds from Programa Operacional Factores de Competitividade – COMPETE [FCOMP-01-0124-FEDER-028751], by national funds from the Portuguese Foundation for Science and Technology (FCT), Lisbon, Portugal [PTDC/DTP-PIC/0239/2012] and by Calouste Gulbenkian Foundation. Liane Correia-Costa was supported by FCT [SFRH/SINTD/95898/2013] and Teresa Sousa was supported by FCT and POPH/FSE (EC) [Ciência 2008 and SFRH/BPD/112005]

Determinants of carotid-femoral pulse wave velocity in prepubertal children

BACKGROUND: Pulse wave velocity (PWV) is a noninvasive technique to evaluate arterial stiffness, a dynamic property of the vessels, reflecting their structure and function. Childhood obesity is associated with several cardiovascular comorbidities and to the progression of atherosclerosis. We aimed to compare carotid-femoral PWV between normal weight and overweight/obese prepubertal children and to quantify its association with other cardiovascular risk factors. METHODS: Cross-sectional study of 315 children aged 8-9years. Anthropometrics, 24-h ambulatory blood pressure (BP) and carotid-femoral PWV were measured. Classification of obesity was according to World Health Organization (WHO) body mass index (BMI)-for-age reference values. RESULTS: Compared to normal weight children, overweight and obese children presented significantly higher levels of PWV (4.95 (P25-P75: 4.61-5.23), 5.00 (4.71-5.33), 5.10 (4.82-5.50) m/s, respectively; ptrend<0.001). Significant positive correlations were found between PWV and total cholesterol, LDL cholesterol, triglycerides, fasting insulin and insulin resistance levels (HOMA-IR) and with high-sensitivity C-reactive protein (hs-CRP). In a multivariate linear regression model adjusted for sex, age, height and 24-h systolic blood pressure z-score, the independent determinants of PWV were BMI, HOMA-IR and the absence of dipping. CONCLUSIONS: The association between PWV and the loss of dipping and insulin resistance levels, independently of the BMI, reinforces the contribution of these comorbidities to vascular injury in early life