Herein, a novel paper-based chemiluminescence (CL) device has been reported for the estimation of total phenolic content of food samples. The CL system implemented on the paper was based on a ...hydrogen peroxide (H2O2)–rhodamine b (RhoB)–cobalt metal organic framework (CoMOF) reaction. It was found that the reaction of H2O2 with RhoB molecules, loaded into the nanopores of CoMOF (R@CoMOF), can produce an intensive CL emission. The experiments on the paper indicated that in the presence of CoMOF, the CL emission was greatly increased. In addition to this strong catalyzing effect, application of CoMOF on the paper improved the stability of the CL system for several days. As a useful analytical application for the obtained paper-based CL device (PCD), it was examined for the detection of phenolic antioxidants. It was observed that the addition of 5 μL of phenolic compounds (PC) on the paper containing the CL reagents can remarkably decrease the CL intensity. This effect was applied to design a simple analytical assay for PC. After the optimization process, the best sensitivity was obtained for gallic acid, quercetin, catechin, kaempferol, and caffeic acid with detection limits of 0.98, 1.36, 1.48, 1.81, and 2.55 ng mL–1, respectively. The relative standard deviations (RSD%) were also less than 5%. This study is the first report on the practical application of PCD using a nanomaterial assisted CL reaction. It is simple, portable, and low-cost and consumes a very low amount of reagents and sample solution. The device was successfully applied in the investigation of total antioxidant capacity of molasses and honey samples.
Ocean tidal currents, water waves and thermal gradients are a great source of renewable energy. Ocean tidal, osmotic, wave and thermal sources have annual potentials of 800, 2,000, 8000–80,000 and ...10,000–87,600TWh, which are more than global 16,000TWh/y electricity demand. Ocean wave generators produce relatively lower output, however, four to eleven meters tidal range stations have large power generation capacities. Abundant ocean heat energy potentially harvested using ocean thermal energy conversion (OTEC) devices and ocean thermo-electric generators (OTEG). Tidal stations may be tidal range or current types, but a wave energy converter (WEC) may be an oscillating water column (OWC), overtopping, heaving, pitching and surging devices. Ocean thermal energy can be harnessed by open, close Rankine cycles, thermo-electric generators and osmotic power plants. Large bays like Turnagain (USA), Annapolis/Minas Passage (Canada), Seven Barrages/Pentland Firth (UK), La Rance (France), Garorim (South Korea) and Mezen/Penzhin (Russia) have huge tidal current power generation capacities. Power Potential from tidal current stations is more than WEC devices which in turn is more than osmotic, OTEC and OTEG technologies. This paper reviews the current state-of-the-art of tidal, wave, OTEC and OTEG ocean energy technologies.
This study reports an economical and portable point-of-care (POC) monitoring device based on artificial multi-enzyme cascade systems for multiple detection purposes. The device was made up of a ...disposable three dimensional microfluidic paper-based analytical device (3D μPAD) with multiple detection zones and a smartphone readout. On-paper synthesis of a multifunctional mimetic composite, based on the CeO2 nanoparticles embedded in the amino-functionalized Fe metal-organic frameworks (CeO2@NH2-MIL-88B(Fe)), for cascade reactions was the main achievement of this work. The 3D μPAD was applied for simultaneous quantification of glucose, fructose, sucrose and maltose, and the detection process consisted of the enzymatic reaction of each sugar by anchored enzymes on the metal-organic frameworks (MOF) and successive oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB). Utilizing the new artificial mimicking system improved the color development uniformity and resulted in a reliable detection tool, with excellent detection limits in the range of 20–280 μM. It was directly applied to analyze the sugars levels of human total blood, urine, semen, honey and juice samples with the relative errors of less than 7.7% compared with the HPLC method. The cost-effective and easy-to-use μPAD has a great potential to be used in either medical diagnostics or the food industry. Also, it can be considered as a competitive POC method for patients in disadvantaged communities or emergencies.
Various concentrations (0.01, 0.03 and 0.05 wt ratios) of graphene oxide (GO) nanosheets were doped into magnesium oxide (MgO) nanostructures using chemical precipitation technique. The objective was ...to study the effect of GO dopant concentrations on the catalytic and antibacterial behavior of fixed amount of MgO. XRD technique revealed cubic phase of MgO, while its crystalline nature was confirmed through SAED profiles. Functional groups presence and Mg-O (443 cm
−1
) in fingerprint region was evident with FTIR spectroscopy. Optical properties were recorded via UV–visible spectroscopy with redshift pointing to a decrease in band gap energy from 5.0 to 4.8 eV upon doping. Electron–hole recombination behavior was examined through photoluminescence (PL) spectroscopy. Raman spectra exhibited D band (1338 cm
−1
) and G band (1598 cm
−1
) evident to GO doping. Formation of nanostructure with cubic and hexagon morphology was confirmed with TEM, whereas interlayer average d-spacing of 0.23 nm was assessed using HR-TEM. Dopants existence and evaluation of elemental constitution Mg, O were corroborated using EDS technique. Catalytic activity against methyl blue ciprofloxacin (MBCF) was significantly reduced (45%) for higher GO dopant concentration (0.05), whereas bactericidal activity of MgO against
E. coli
was improved significantly (4.85 mm inhibition zone) upon doping with higher concentration (0.05) of GO, owing to the formation of nanorods.
Obesity is a chronic disease, warranting long-term medical intervention. We evaluated effects of testosterone (T) therapy (Th) in men with T deficiency with normal weight, overweight and obesity on ...anthropometric and metabolic parameters, compared with untreated men.
Hypogonadal men (n = 823) with total T ≤ 12.1 nmol/L (age: 60.6 ± 7.0 years) participated in an ongoing registry study. Among these men 474 (57.6%) were obese, 286 (34.8%) overweight and 63 (7.7%) had normal weight. T undecanoate injections were administered to 428 men and 395 remained untreated. Anthropometric and metabolic parameters were measured at least twice a year and changes adjusted for confounding factors to account for baseline differences between groups.
Long-term TTh in hypogonadal men, irrespective of weight at baseline, produced improvements in body weight, waist circumference (WC) and body mass index (BMI). Furthermore, TTh decreased fasting blood glucose and HbA
and improved lipid profiles. Gradual decreases in blood pressure (systolic and diastolic) and pulse pressure occurred in men treated with T in each group. Marked reductions in mortality and major cardiovascular events were recorded in men receiving TTh.
Our findings demonstrate that TTh produces reductions in weight, WC, and BMI. There were 77 (19.5%) deaths in the untreated groups and 23 (5.4%) in the T-groups. Based on these findings we suggest that long-term TTh in overweight and obese hypogonadal men produces progressive and sustained clinically meaningful weight loss and that TTh may contribute to reductions in mortality and incident major adverse cardiovascular events.
Point-of-care (POC) diagnostic devices play significant roles in delivering vital surveillance information and providing proper and timely care to patients. There is a challenge in the development of ...new diagnostic tools to overcome their current shortcomings in terms of cost issues, accuracy and performance. Herein, a highly efficient paper-based analytical device based on a 2D metal-organic framework (MOF) has been reported for the colorimetric/fluorometric monitoring of glucose. Because of the inherent bifunctional activity of cobalt-terephthalate MOF (CoMOF) nanosheets, great improvements were made to the stability and performance of glucose oxidase (GOX) and to its catalytic effect on the reaction of o-phenylenediamine (OPD) and H2O2. The exceptional behavior of 2D CoMOF, along with a precise smartphone readout, led to the rapid and sensitive colorimetric/fluorometric detection of glucose in biological samples. Paper modified by CoMOF and GOX was stable for a long time, and a yellow-brown color and a high fluorescence emission were observed after the addition of a low volume of sample and OPD solutions. The probe showed a wide linear effectiveness range of 50 μM-15 mM, with colorimetric and fluorometric detection limits of 16.3 and 3.2 μM, respectively. Despite its great simplicity, the developed probe showed high performance and accuracy for the quantification of glucose.
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•Exceptional bifunctional activity of 2D cobalt metal-organic framework (CoMOF).•Notable enhancement of the stability and performance of GOX on the paper by CoMOF.•Superb catalyzing effect of CoMOF on the dissociation of H2O2 to hydroxyl radicals.•Development of paper-based diagnostic assay for glucose monitoring in blood.•Recording of colorimetric/fluorometric signals by smartphone readout.
This study aimed to identify and rank the different aspects of households' vulnerability to food insecurity.
The data were collected by a standard online questionnaire. The Household Food Insecurity ...Access Scale was used to assess food insecurity levels, and first-order structural equation modelling was applied to determine factors that affect food insecurity. Seven dimensions of vulnerability were measured: economic, social, cultural, human, physical, psychology and information, using thirty-seven items extracted from the related literature review.
This study was implemented in Tehran province in Iran.
The sample included 392 families residing in Tehran province which was determined using random sampling.
About 61 % of the total sample faced food insecurity, at marginal, moderate and severe levels. Economic, psychological and human aspects of vulnerability had the highest effect on food insecurity during the initial COVID-19 lockdown.
Authorities and policymakers must provide economic and financial support to vulnerable households. Abolition of US economic and financial sanctions imposed on Iran must be implemented to battle with COVID-19 in this country.
Objectives To summarise evidence on the associations of maternal anaemia and prenatal iron use with maternal haematological and adverse pregnancy outcomes; and to evaluate potential exposure-response ...relations of dose of iron, duration of use, and haemoglobin concentration in prenatal period with pregnancy outcomes.Design Systematic review and meta-analysisData sources Searches of PubMed and Embase for studies published up to May 2012 and references of review articles.Study selection criteria Randomised trials of prenatal iron use and prospective cohort studies of prenatal anaemia; cross sectional and case-control studies were excluded.Results 48 randomised trials (17 793 women) and 44 cohort studies (1 851 682 women) were included. Iron use increased maternal mean haemoglobin concentration by 4.59 (95% confidence interval 3.72 to 5.46) g/L compared with controls and significantly reduced the risk of anaemia (relative risk 0.50, 0.42 to 0.59), iron deficiency (0.59, 0.46 to 0.79), iron deficiency anaemia (0.40, 0.26 to 0.60), and low birth weight (0.81, 0.71 to 0.93). The effect of iron on preterm birth was not significant (relative risk 0.84, 0.68 to 1.03). Analysis of cohort studies showed a significantly higher risk of low birth weight (adjusted odds ratio 1.29, 1.09 to 1.53) and preterm birth (1.21, 1.13 to 1.30) with anaemia in the first or second trimester. Exposure-response analysis indicated that for every 10 mg increase in iron dose/day, up to 66 mg/day, the relative risk of maternal anaemia was 0.88 (0.84 to 0.92) (P for linear trend<0.001). Birth weight increased by 15.1 (6.0 to 24.2) g (P for linear trend=0.005) and risk of low birth weight decreased by 3% (relative risk 0.97, 0.95 to 0.98) for every 10 mg increase in dose/day (P for linear trend<0.001). Duration of use was not significantly associated with the outcomes after adjustment for dose. Furthermore, for each 1 g/L increase in mean haemoglobin, birth weight increased by 14.0 (6.8 to 21.8) g (P for linear trend=0.002); however, mean haemoglobin was not associated with the risk of low birth weight and preterm birth. No evidence of a significant effect on duration of gestation, small for gestational age births, and birth length was noted.Conclusions Daily prenatal use of iron substantially improved birth weight in a linear dose-response fashion, probably leading to a reduction in risk of low birth weight. An improvement in prenatal mean haemoglobin concentration linearly increased birth weight.
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