294 research outputs found
Dielectric properties measurements of brown and white adipose tissue in rats from 0.5 to 10 GHz
Brown adipose tissue (BAT) plays an important role in whole body metabolism and with appropriate stimulus could potentially mediate weight gain and insulin sensitivity. Although imaging techniques are available to detect subsurface BAT, there are currently no viable methods for continuous acquisition of BAT energy expenditure. Microwave (MW) radiometry is an emerging technology that allows the quantification of tissue temperature variations at depths of several centimeters. Such temperature differentials may be correlated with variations in metabolic rate, thus providing a quantitative approach to monitor BAT metabolism. In order to optimize MW radiometry, numerical and experimental phantoms with accurate dielectric properties are required to develop and calibrate radiometric sensors. Thus, we present for the first time, the characterization of relative permittivity and electrical conductivity of brown (BAT) and white (WAT) adipose tissues in rats across the MW range 0.5-10GHz. Measurements were carried out in situ and post mortem in six female rats of approximately 200g. A Cole-Cole model was used to fit the experimental data into a parametric model that describes the variation of dielectric properties as a function of frequency. Measurements confirm that the dielectric properties of BAT (εr = 14.0-19.4, σ = 0.3-3.3S/m) are significantly higher than those of WAT (εr = 9.1-11.9, σ = 0.1-1.9S/m), in accordance with the higher water content of BAT
The use of artificial neural network to evaluate the effects of human and physiographic factors on forest stock volume
Increase in human factors coupled with physiographic factors will impact stock volume in forest ecosystems. The scale of this process and critical information in forestry management provide an incentive for the development of model to predict the forest stock volume. In this paper, we use data derived from Siahrood, Guilan Province, Iran using Field inventory by cluster sampling in a network (1 × 1 km) with 90 clusters and 900 circular plots (1000 m2). To evaluate modeling approaches for stock volume responses to changing condition. The relationship between the standing volume and human factors and each physiographic factor were examined using Pearson and the Artificial Neural Network method. Based on Field observations it was observed that different stock volume exhibit in specific physiographic response to population density, livestock density, distance from village, aspect, slope and elevation. Results show that Multilayer Neural Networks with 12 nodes can predict the forest stock volume with the lowest RMSE (48.76m3). In addition, the artificial neural network designed for the buffer of three populations with 85.5% accuracy was selected as the best model to predict the volume based on the mentioned components. The results suggest ANN is an effective approach to predict exact forest stock volume and human factors in certain topography conditions and provides useful information for the acceptable amount of standing inventory using the present human population in future experiment.Keywords: stock volume, human factors, physiographic factors, neural network Corresponding autho
Attitudes, Perceptions, and Tendencies of the Iranian Students in Medical Fields towards Cheating and Academic Dishonesty
Background and Objectives: Despite universities initiating different controlling systems, cheating is still rampant and a global phenomena. One side of the problem of cheating involves the attitudes, perceptions and tendencies of the university students towards cheating and academic misconduct. The present survey seeks to elaborate on the above aspects among the students at one of the most important universities in Tehran, Iran. Methods and Sample: The study has benefitted from the translated and validated version of the questionnaire used by Lupton and Chapman (2002). The sample included 386 students studying at Shahid Beheshti University of Medical Sciences (SBMU) in Tehran in different fields of medical sciences. Findings and Discussion: The survey has found some very interesting results on what Iranian university students think of cheating and academic dishonesty, despite all the controlling systems used in assigning homework and initiating mid-term and final exams. Almost 81.1 % of the female students and 85.2 % of male students did not consider “giving the exam answers to someone at the following semester” an act of cheating. Moreover, 72.2 % of students responded that they had not cheated. Interestingly, 65.4 % of the respondents have admitted that they had given information of a previous exam to another student. The results showed that sex did not have any role in cheating and academic dishonesty (p=0.826)
Influence of zinc incorporation on microstructure of hydroxyapatite to characterize the effect of pH and calcination temperatures
AbstractThis work was focused to study the existence of Zn2+ in structure, chemical composition as well as particle and crystallite size of hydroxyapatite (HAp) to characterize the effect of pH of the solution and calcination temperature. Non-stoichiometric HAp (nHAp) powders containing 4at.% zinc fraction were synthesized via solution–precipitation method. In order to characterize the effect of pH (values: 9 and 10.5) and two calcination temperatures (550 and 1000°C) on chemical composition, molecule internal bonds, particle and crystallite size of the synthesized powders, XRD, EDS, FTIR and SEM techniques were utilized. The results showed that zinc cations could be incorporated in the HAp atomic structure to form low crystalline single phase of nHAP. The pH adjustment to 10.5 caused the formation of powders with smaller particle and crystallite sizes. The results also indicated that calcination temperature up to 1000°C caused decomposition of zinc doped nHAp to β-tri calcium phosphate and tri zinc calcium phosphate phases which are used to control the speed of biodegradation
Prevalence of chronic kidney disease and its associated risk factors: The first report from Iran using both microalbuminuria and urine sediment
Background: The incidence of major risk factors of chronic kidney disease (CKD) in the world is on the rise, and it is expected that this incidence and prevalence, particularly in developing countries, will continue to increase. Using data on urinary sediment and microalbuminuria, we aimed to estimate the prevalence of CKD in northeast Iran. Methods: In a cross-sectional study, the prevalence of CKD in a sample of 1557 regionally representative people, aged � 18 years, was analyzed. CKD was determined based on glomerular filtration rate (GFR) and microalbuminuria. Life style data, urine and blood samples were collected. Urine samples without any proteinuria in the initial dipstick test were checked for qualitative microalbuminuria. If the latter was positive, quantitative microalbuminuria was evaluated. Results: 1557 subjects with a mean age of 56.76 ± 12.04 years were enrolled in this study. Based on the modifcation of diet in renal disease (MDRD) equation, 137 subjects (8.89%) were categorized as CKD stages III-V. Based on urine abnormalities, the prevalence of combined CKD stages I and II was 10.63%, and based on macro- and microalbuminuria it was 14.53%. The prevalence of CKD was significantly associated with sex, age, marital status, education, diabetes mellitus (DM), hypertension (HTN), ischemic heart disease (IHD), waist to hip ratio, myocardial infarction (MI), and cerebrovascular accident (CVA). Conclusion: CKD and its main risk factors are common and represent a definite health threat in this region of Iran. Using and standardizing less expensive screening tests in low resource countries could be a good alternative that may improve the outcome through early detection of CKD
Preventing PTSD, depression and associated health problems in student paramedics: Protocol for PREVENT-PTSD, a randomised controlled trial of supported online cognitive training for resilience versus alternative online training and standard practice
This the author accepted manuscript. The final version is available from the publisher via the DOI in this record.Introduction: Emergency workers dedicate their lives to promoting public health and safety, yet suffer higher rates of post-traumatic stress disorder (PTSD) and major depression (MD) compared with the general population. They also suffer an associated increased risk for physical health problems, which may be linked to specific immunological and endocrine markers or changes in relevant markers. Poor physical and mental health is costly to organisations, the National Health Service and society. Existing interventions aimed at reducing risk of mental ill health in this population are not very successful. More effective preventative interventions are urgently needed. We first conducted a large-scale prospective study of newly recruited student paramedics, identifying two cognitive factors (rumination and resilience appraisals) that predicted episodes of PTSD and MD over a 2-year period. We then developed internet-delivered cognitive training for resilience (iCT-R), a supported online intervention, to modify cognitive predictors. This protocol is for a randomised controlled trial to evaluate the efficacy of the resilience intervention. Methods and analysis: 570 student paramedics will be recruited from participating universities. They will be randomly allocated to iCT-R or to supported online training of an alternative, widely available intervention or to training-as-usual. Follow-up will occur after the intervention/standard practice period and at 6, 12 and 24 months. Primary outcomes include rates of PTSD and MD and subsydnromal PTSD and MD, measured by the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, fifth edition, the Patient-Health Questionnaire-9 and the Post-traumatic Stress Disorder Checklist for Diagnostic and Statistical Manual of Mental Disorders, fifth edition. Secondary outcomes include measures of resilience, rumination, anxiety, psychological distress, well-being, salivary cortisol, plasma levels of C-reactive protein, smoking and alcohol use, weight gain, sleep problems, health-related quality of life, health resource utilisation and productivity. Ethics and dissemination: The Medical Sciences Inter-Divisional Research Ethics Committee at the University of Oxford granted approval, reference: R44116/RE001. The results will be published in a peer-reviewed journal. Access to raw data and participant information will be available only to members of the research team. Trial registration number ISRCTN16493616; Pre-results.Wellcome TrustMQ: Transforming Mental HealthNIHR: National Institute for Health Researc
In vitro Anti-proliferative and Apoptotic Activities of Eurycoma longifolia Jack (Simaroubaceae) on HL-60 Cell Line
Purpose: To investigate the anti-proliferative, apoptotic and differentiating activities of Eurycoma longifolia root extracts on HL-60 leukemic cells.Methods: HL-60 cells were treated with different partially purified sub-fractions (F1 – F3) derived from the resin chromatography of the crude methanol root extract of E. longifolia roots, at different doses andtime points. The anti-proliferative activity of E. longifolia was assessed via cell counting and trypan blue exclusion. Apoptosis was evaluated via Annexin-V FITC/IP and Hoechst staining. Flow cytometry and Wright staining were used to assess its differentiation activities.Results: F1 showed unremarkable growth inhibition rate while F2 and F3 showed growth inhibitory effects with median inhibitory concentration (IC50) values of 15.2 and 28.6 ìg/ml, respectively. Treatment with F2 and F3 (100 ìg/ml) for 96 h increased cell death from 3.3 to 95.5 and 76.3 %,respectively. Treatment with F2 (50 ìg/ml) induced apoptosis by 14, 19.5 and 25 % after 24, 48 and 72 h, respectively. No differentiation activity was observed, as indicated by absence of myeloid maturation and a non-significant CD14 positivity (p > 0.05).Conclusion: E. longifolia extract (F2) showed promising anti-leukemic activity and can be a candidate for the development of a drug for the treatment of acute promyelocytic leukemia (APL).Keywords: Acute promyelocytic leukemia (APL), HL-60 cells, Eurycoma longifolia, Apoptosis, Antiproliferation, Differentiatio
Multichannel Impedance Cytometry Downstream of Cell Separation by Deterministic Lateral Displacement to Quantify Macrophage Enrichment in Heterogeneous Samples
A pilot double-blind randomised placebo-controlled trial of the effects of fixed-dose combination therapy ('polypill') on cardiovascular risk factors
SummaryAim: Our objective was to investigate the effects and tolerability of fixed-dose combination therapy on blood pressure and LDL in adults without elevated blood pressure or lipid levels. Methods: This was a double-blind randomised placebo-controlled trial in residents of Kalaleh, Golestan, Iran. Following an 8-week placebo run-in period, 475 participants, aged 50 to 79 years, without cardiovascular disease, hypertension or hyperlipidaemia were randomised to fixed-dose combination therapy with aspirin 81 mg, enalapril 2.5 mg, atorvastatin 20 mg and hydrochlorothiazide 12.5 mg (polypill) or placebo for a period of 12 months. The primary outcomes were changes in LDL-cholesterol, systolic and diastolic blood pressure and adverse reactions. Analysis was by intention-to-treat basis. Results: At baseline, there were differences in systolic blood pressure (6 mmHg). Taking account of baseline differences, at 12 months, polypill was associated with statistically significant reductions in blood pressure (4.5/1.6 mmHg) and LDL-cholesterol (0.46 mmol/l). The study drug was well tolerated, but resulted in the modest reductions in blood pressure and lipid levels. Conclusion: The effects of the polypill on blood pressure and lipid levels were less than anticipated, raising questions about the reliability of the reported compliance. There is a case for a fully powered trial of a polypill for the prevention of cardiovascular disease. © 2010 Blackwell Publishing Ltd
Chemical Composition, Antioxidant and Antibacterial Activities of Thymus broussonetii Boiss and Thymus capitatus (L.) Hoffmann and Link Essential Oils
Thymus capitatus and Thymus broussonnetii are two Moroccan endemic medicinal plants used traditionally by the local population. The present study aims to investigate their essential oil chemical composition, antioxidant and antibacterial activities. The chemical composition of the essential oils was determined using the GC-MS analysis, the antioxidant activity assessed using DPPH and FRAP methods while the antimicrobial activity was evaluated against nine bacteria species tested (Enterococcus faecalis, Serratia fonticola, Acinetobacter baumannii, Klebsiella oxytoca, sensitive Klebsiella pneumoniae, sensitive Escherichia coli, resistant Escherichia coli, resistant Staphylococcus aureus and Enterobacter aerogenes). The major identified compounds of T. capitatus essential oil where carvacrol (75%) and p-cymene (10.58%) while carvacrol (60.79%), thymol (12.9%), p-cymene (6.21%) and γ-terpinene (4.47%) are the main compounds in T. broussonnetii essential oil. The bioactivity of the essential oils of the two species of thyme was explained by their richness in oxygenated monoterpenes known for their great effectiveness with an IC50 of 3.48 ± 0.05 and 4.88 ± 0.04 μL/mL and EC50 of 0.12 ± 0.01 and 0.20 ± 0.02 μL/mL in the DPPH and FRAP assays, respectively, with an important antibacterial activity. These results encourage the use of these plants as a source of natural antioxidants, and antibacterial additives, to protect food from oxidative damage and to eliminate bacteria that are responsible for nosocomial infections
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