Potentiometric sensors selective for Cu(II) determination in real water samples and biological fluids based on graphene and multi-walled carbon nanotubes modified graphite electrodes

162-173Three newly synthesized Cu(II) ion selective electrodes based on 1,8-dihydoxyanthraquinone (DHAQ), as an ionophore, have been developed. Carbon paste electrode has been modified with DAHQ (sensor I), graphene and DHAQ (sensor II) and multi-walled carbon nanotubes (MWCNTs) and DHAQ (sensor III), in order to improve the conductivity and transduction of chemical signal to electrical signal. Under optimized conditions, the electrodes I, II and III revealed Nernstian slopes of 29.78 ± 0.17, 30.25 ± 0.12, and 30.55 ± 0.19 mV decade-1, respectively, at 25±1 °C covering a wide concentration range from 1×10–6 to 1×10−1 mol L–1 for sensors I and II and from 1×10–5 to 1×10−1 mol L–1 for sensor III with detection limit values of 8×10−7, 5×10−7, and 3.3×10−6 mol L-1, respectively. The response of the proposed electrodes is very fast and independent of pH in the range of 2.4–6.5 and the response mechanism is studied using IR, SEM and EDX analyses. Selectivity coefficients have been determined by applying separate solution method and matched potential method, where the obtained values indicated the good discrimination of Cu(II) from other cations by the proposed sensors. The developed sensors have been used successfully for quantitative determination of Cu(II) ions in different matrix of spiked real water samples and biological fluids (urine and serum). These sensors have also been used successfully as indicator electrodes in the potentiometric titration of Cu(II) with EDTA

Polyamines in foods: development of a food database

Background: Knowing the levels of polyamines (putrescine, spermidine, and spermine) in different foods is of interest due to the association of these bioactive nutrients to health and diseases. There is a lack of relevant information on their contents in foods. Objective: To develop a food polyamine database from published data by which polyamine intake and food contribution to this intake can be estimated, and to determine the levels of polyamines in Swedish dairy products. Design: Extensive literature search and laboratory analysis of selected Swedish dairy products. Polyamine contents in foods were collected using an extensive literature search of databases. Polyamines in different types of Swedish dairy products (milk with different fat percentages, yogurt, cheeses, and sour milk) were determined using high performance liquid chromatography (HPLC) equipped with a UV detector. Results: Fruits and cheese were the highest sources of putrescine, while vegetables and meat products were found to be rich in spermidine and spermine, respectively. The content of polyamines in cheese varied considerably between studies. In analyzed Swedish dairy products, matured cheese had the highest total polyamine contents with values of 52.3, 1.2, and 2.6 mg/kg for putrescine, spermidine, and spermine, respectively. Low fat milk had higher putrescine and spermidine, 1.2 and 1.0 mg/kg, respectively, than the other types of milk. Conclusions: The database aids other researchers in their quest for information regarding polyamine intake from foods. Connecting the polyamine contents in food with the Swedish Food Database allows for estimation of polyamine contents per portion

Cancer in Children at El Obeid Hospital, Western Sudan.

Background: Cancers form one of the major causes of death in children. They differ markedly from adult cancers in their nature, distribution and prognosis. Objectives: To determine the pattern of childhood cancer at El Obeid Hospital, Western Sudan. Patients and Methods: The records of all patients admitted with cancer aged 15 years and below tothe wards of El Obeid Hospital, Western Sudan over two years were studied. The cancers were classified according to the organs affected and then ranked in their order of relative frequency. The mean age, age range, gender and the relative frequency rates were calculated. Results: There were 40 newly diagnosed childhood cancer patients during the study period. Males were 29 patients (72.5%). The age ranged three months to 14 years. Leukaemias were the most common malignancy in both sexes, followed by bone tumours and then nephroblastoma.Conclusions: Cancers in children were seen at Western Sudan, and cases admitted to hospital only reflect the tip of the iceberg as many cases were directly referred to Oncology Hospitals. Establishment of a local radiation and isotopes centre is needed in this part of the country to provide oncology services and to integrate preventive programs.Key words: Acute lymphocytic leukaemia, osteosarcoma, nephroblastoma, Western Sudan

Online health information seeking among patients attending primary care clinics in Bahrain: a cross-sectional study

Background: Online health information seeking is prevalent among patients nowadays and this might influence the medical consultation outcome and affect the patient-doctor relationship. Objective was to determine the prevalence of online health information seeking behavior among primary care clinics attendees in Bahrain and the impact on patient-doctor relationship.Methods: Patients attending primary care clinics in Bahrain were asked to complete a previously adapted self-administered questionnaire that studied demographical data, frequency of online use in general and for health-related information and pattern of online health information seeking including reasons searched for and sources used. The logistic regression analysis done to explore respondent’s characteristics with health seeking behavior online.Results: Ninety-seven percent (97%) of the study population used the internet and (94.7%) had searched for online health information. The two main types of information sought were disease-related information (88.7%) and complementary and alternative medicine (55%). Fifty-three percent used reliable sources (i.e., Ministry of Health (43.3%), hospital websites (14.9%), medical encyclopedias (e.g., PubMed and Medline plus) (17.4%).  Approximately (39.3%) use social networks to find information (including Facebook and Twitter). Convenience and usability were the main reasons (88.9%). Fifty-five percent (55%) asked or shared health information they found online with their doctor.Conclusions: Online health information seeking is highly prevalent in Bahrain among primary care clinic attendees. Sources were chosen mainly for their convenience, availability and being easily understood. A good number shared health information found online with their physicians. Physicians should be aware about patients’ online health seeking behavior and address that during consultation

Hybrid PSO-tuned PID and hysteresis-observer based control for piezoelectric micropositioning stages

Piezo-actuated micropositioning stages consist of a piezoelectric actuator that operates a positioning system. Hysteresis nonlinearity is one of the significant variables limiting the positioning precision of these stages. This paper introduces a technique of developing a hybrid controller for a precise positioning tracking of a piezoelectric micropositioning system. Bouc-Wen nonlinear hysteresis model is utilized to denote the hysteresis nonlinear phenomenon of the piezo-actuated system. A hysteresis observer-based feedforward controller is designed based on Luenberger observer. This feedforward controller is then coupled with a particle swarm optimization (PSO)-based proportional-integral-derivative (PID) feedback controller to form a hybrid controller. A new fitness function is used to compute the optimal PID gains. This fitness function is intended to reduce the overshoot, steady-state error, and the rise and settling times. The findings of this work indicate that using the developed controller structure can significantly decrease the hysteresis effect. In addition, the proposed structure shows the ability to reduce the error is to 0.046% of the maximum displacement range. Such performance demonstrates that the proposed hybrid control structure is efficient for precise micropositioning applications.Piezo-actuated micropositioning stages consist of a piezoelectric actuator that operates a positioning system. Hysteresis nonlinearity is one of the significant variables limiting the positioning precision of these stages. This paper introduces a technique of developing a hybrid controller for a precise positioning tracking of a piezoelectric micropositioning system. Bouc-Wen nonlinear hysteresis model is utilized to denote the hysteresis nonlinear phenomenon of the piezo-actuated system. A hysteresis observer-based feedforward controller is designed based on Luenberger observer. This feedforward controller is then coupled with a particle swarm optimization (PSO)-based proportional-integral-derivative (PID) feedback controller to form a hybrid controller. A new fitness function is used to compute the optimal PID gains. This fitness function is intended to reduce the overshoot, steady-state error, and the rise and settling times. The findings of this work indicate that using the developed controller structure can significantly decrease the hysteresis effect. In addition, the proposed structure shows the ability to reduce the error is to 0.046% of the maximum displacement range. Such performance demonstrates that the proposed hybrid control structure is efficient for precise micropositioning applications

Self-folding nano- and micropatterned hydrogel tissue engineering scaffolds by single step photolithographic process

Current progress in tissue engineering is focused on the creation of environments in which cultures of relevant cells can adhere, grow and form functional tissue. We propose a method for controlled chemical and topographical cues through surface patterning of self-folding hydrogel films. This provides a conversion of 2D patterning techniques into a viable method of manufacturing a 3D scaffold. While similar bilayers have previously been demonstrated, here we present a faster and high throughput process for fabricating self-folding hydrogel devices incorporating controllable surface nanotopographies by serial hot embossing of sacrificial layers and photolithography

Oil Palm Counting and Age Estimation from WorldView-3 Imagery and LiDAR Data Using an Integrated OBIA Height Model and Regression Analysis

The current study proposes a new method for oil palm age estimation and counting. A support vector machine algorithm (SVM) of object-based image analysis (OBIA) was implemented for oil palm counting. It was integrated with height model and multiregression methods to accurately estimate the age of trees based on their heights in five different plantation blocks. Multiregression and multi-kernel size models were examined over five different oil palm plantation blocks to achieve the most optimized model for age estimation. The sensitivity analysis was conducted on four SVM kernel types (sigmoid (SIG), linear (LN), radial basis function (RBF), and polynomial (PL)) with associated parameters (threshold values, gamma γ, and penalty factor (c)) to obtain the optimal OBIA classification approaches for each plantation block. Very high-resolution imageries of WorldView-3 (WV-3) and light detection and range (LiDAR) were used for oil palm detection and age assessment. The results of oil palm detection had an overall accuracy of 98.27%, 99.48%, 99.28%, 99.49%, and 97.49% for blocks A, B, C, D, and E, respectively. Moreover, the accuracy of age estimation analysis showed 90.1% for 3-year-old, 87.9% for 4-year-old, 88.0% for 6-year-old, 87.6% for 8-year-old, 79.1% for 9-year-old, and 76.8% for 22-year-old trees. Overall, the study revealed that remote sensing techniques can be useful to monitor and detect oil palm plantation for sustainable agricultural management

The relationship between lipid profile after fat loading and coronary artery disease severity assessed by SYNTAX score

BACKGROUND: Dyslipidemia is an established risk factor for coronary artery disease (CAD). Despite this, only half of CAD patients present with fasting dyslipidemia. Some reports have linked postprandial lipemia to atherosclerosis. We aimed to test the relationship between postprandial lipid profile (after fat loading) and CAD severity assessed by the SYNTAX score.METHODS: We included 53 patients with documented CADs. We checked both fasting and postprandial (2 hours) lipograms after fat loading with 17 g/body surface area (m2). Then we assessed CAD severity via coronary angiography using the SYNTAX score. Our study is registered in clinicaltrials.gov (NCT03175393).RESULTS: *53 patients with age 57.92 ± 7.82 were recuirted. 36 (68% ) of them were male .We observed a significant increase in postprandial triglycerides (TGs); TGs (154.30 ±73.23 vs. 128.07 ± 69.40 mg/dl; P < 0.001), very-low-density lipoproteins (VLDL) (30.85 ± 14.65 vs. 25.60 ± 13.93 mg/dl; P < 0.001) as well as a significant decrease in the postprandial level of total cholesterol (162.37 ± 45.86 vs. 168.26 ± 45.96 mg/dl; P = 0.03) in comparison to their fasting level.We found that the SYNTAX score had a significant positive moderate correlation with 2-hour postprandial TGs (r = 0.55; P < 0.001) and 2-hour postprandial VLDL (r = 0.50; P < 0.001). Based on the current study, predictors of high Syntax score were older age OR: 1.23( 1.11-3.47); P< 0.001, post-prandial triglyceride OR: 2.34 (1.89-5.66); P< 0.001 and post-prandial VLDL OR: 1.76( 1.50-3.49); P< 0.001CONCLUSION: Postprandial lipograms, especially TGs, are significantly and positively related to CAD severity