Chemical characteristics of wildfire ash across the globe and their environmental and socio-economic implications.

The mobilisation of potentially harmful chemical constituents in wildfire ash can be a major consequence of wildfires, posing widespread societal risks. Knowledge of wildfire ash chemical composition is crucial to anticipate and mitigate these risks. Here we present a comprehensive dataset on the chemical characteristics of a wide range of wildfire ashes (42 types and a total of 148 samples) from wildfires across the globe and examine their potential societal and environmental implications. An extensive review of studies analysing chemical composition in ash was also performed to complement and compare our ash dataset. Most ashes in our dataset had an alkaline reaction (mean pH 8.8, ranging between 6 and 11.2). Important constituents of wildfire ash were organic carbon (mean: 204 g kg-1), calcium, aluminium, and iron (mean: 47.9, 17.9 and 17.1 g kg-1). Mean nitrogen and phosphorus ranged between 1 and 25 g kg-1, and between 0.2 and 9.9 g kg-1, respectively. The largest concentrations of metals of concern for human and ecosystem health were observed for manganese (mean: 1488 mg kg-1; three ecosystems > 1000 mg kg-1), zinc (mean: 181 mg kg-1; two ecosystems > 500 mg kg-1) and lead (mean: 66.9 mg kg-1; two ecosystems > 200 mg kg-1). Burn severity and sampling timing were key factors influencing ash chemical characteristics like pH, carbon and nitrogen concentrations. The highest readily dissolvable fractions (as a % of ash dry weight) in water were observed for sodium (18 %) and magnesium (11.4 %). Although concentrations of elements of concern were very close to, or exceeded international contamination standards in some ashes, the actual effect of ash will depend on factors like ash loads and the dilution into environmental matrices such as water, soil and sediment. Our approach can serve as an initial methodological standardisation of wildfire ash sampling and chemical analysis protocols.

Assessment of groundwater quality and human health risks of nitrate and fluoride contamination in a rapidly urbanizing region of India.

Groundwater contamination studies are important to understand the risks to public health. In this study, groundwater quality, major ion chemistry, sources of contaminants, and related health risks were evaluated for North-West Delhi, India, a region with a rapidly growing urban population. Groundwater samples collected from the study area were analysed for physicochemical parameters - pH, electrical conductivity, total dissolved solids, total hardness, total alkalinity, carbonate, bicarbonate, chloride, nitrate, sulphate, fluoride, phosphate, calcium, magnesium, sodium and potassium. Investigation of hydrochemical facies revealed that bicarbonate was the dominant anion while magnesium was the dominant cation. Multivariate analysis using principal component analysis and Pearson correlation matrix indicated that major ion chemistry in the aquifer under study is primarily due to mineral dissolution, rock-water interactions and anthropogenic factors. Water quality index values showed that only 20% of the samples were acceptable for drinking. Due to high salinity, 54% of the samples were unfit for irrigation purposes. Nitrate and fluoride concentrations ranged from 0.24 to 380.19 mg/l and 0.05 to 7.90 mg/l, respectively due to fertilizer use, wastewater infiltration and geogenic processes. The health risks from high levels of nitrate and fluoride were calculated for males, females, and children. It was found that health risk from nitrate is more than fluoride in the study region. However, the spatial extent of risk from fluoride is more indicating that more people suffer from fluoride pollution in the study area. The total hazard index for children was found to be more than adults. Continuous monitoring of groundwater and application of remedial measures are recommended to improve the water quality and public health in the region.

Clean quality control of agricultural and non-agricultural lime by rapid and accurate assessment of calcium and magnesium contents via proximal sensors.

Ca and Mg are the most important chemical elements in lime. Properly measuring Ca and Mg contents is essential to assess the quality of lime products. Quality control guarantees the adequate use of lime in industrial processes, in soils, and helps avoiding adulteration. Proximal sensors can aid in this process by determining Ca and Mg contents easily, rapidly and without producing chemical waste. The objective of this study was to evaluate the use an environmentally-friendly method of analyzing the quality of lime. We studied 1) the use of portable X-ray fluorescence (pXRF) to predict concentrations of Ca and Mg in lime, 2) tested if NixPro™ sensor can improve prediction accuracy and 3) tested if sample preparation methods (grinding) affect analyses. 74 samples of lime were analyzed by two different laboratories (lab. 1 = 38, lab. 2 = 36). All samples submitted to pXRF and NixPro™ analyses. Sensor analyses were done in whole (CP) and ground (AQ) samples to test the effect of sample preparation in prediction performance. High correlation was found between Ca and Mg contents measured via pXRF and laboratory analyses. Mg-CP presented the highest correlation coefficient (r = 0.81); Mg-AQ, the lowest (0.57). Predictions presented good performance (R2 > 0.68); Mg had the best results (0.86). Separating models per laboratory showed that some datasets are harder to model, probably due to variability in the source material (limestone). The addition of NixPro™ data contributed to improve prediction accuracy, although slightly. Predictions using CP samples presented the best results, especially for Mg, indicating that grinding is not necessary. This pioneer study demonstrated that fused proximal sensors can be used to rapidly and easily determine contents of Ca and Mg in soil amendments without producing chemical waste.

Spatiotemporal evaluation and assessment of shallow groundwater quality for irrigation of a tropical coastal groundwater basin.

The present study aims at analyzing groundwater quantity and quality simultaneously to identify its availability and suitability for irrigation. Various water quality indices were used to assess (i) origin of the groundwater sources (Gibbs diagram); (ii) salinity, alkalinity, and sodium hazard (sodium adsorption ratio, exchangeable sodium percentage, Kelly's ratio, US Salinity Laboratory diagram, Wilcox diagram); (iii) magnesium hazard (magnesium absorption ratio); (iv) carbonate and bicarbonate hazard (residual sodium carbonate); (v) hydro-chemical facie and evaluation (Piper diagram and Expanded Durov diagram); and (vi) statistical relationship among the variables, sample sites, and spatiotemporal grouping (principal component analysis and cluster analysis). The overall objective is to quantify the irrigation suitability of groundwater reserves. Gibb's diagram suggests that the groundwater quality is mainly controlled by rock-water interaction. Piper trilinear showed the presence of various types of hydro-chemical facies such as Ca-Mg-HCO3, mixed, and sodium bicarbonate. The expanded Durov diagram revealed the hydro-chemical evolution, grouping, and areal distribution of the groundwater samples. USSL diagram, Wilcox diagram, Kelly's ratio, magnesium hazard, and permeability index suggest that the groundwater quality is suitable for irrigation. Kaiser-Meyer-Olkin (KMO) and Bartlett's tests confirmed the applicability of principal component analysis (PCA), which indicates that groundwater quality is controlled by rock-water interaction mainly. It also suggests that the groundwater has carbonate dissolution, which indicates the groundwater's hardness increased. Cluster analysis (CA) from the year 2000 to 2010 shows 4 to 8 groups present within the study area. Irrigation water quality suitability map and predicted groundwater potential zone map together act as a master tool for deciding tube well location, pumping schedule, and crop planning for the sustainability of the agriculture eco-system in the study area. The implementation of the aforementioned activities in the study area will further stop the advancement of the seawater intrusion front. The methodology shows the potential applicability for similar coastal groundwater basins worldwide with or without modification.

Comparison and Risk Assessment of Macroelements and Trace Metals in Commercial Teas from Different Regions of China.

Tea (Camellia sinensis L.) is one of the most widely consumed non-alcoholic beverages worldwide. In the present study, 73 commercial tea samples were collected from tea plantations in the Southwest, South, Jiangnan, and Jiangbei regions of China. The contents of four macroelements (phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg)) and 15 trace metals (arsenic (As), cadmium (Cd), chromium (Cr), mercury (Hg), lead (Pb), zinc (Zn), aluminium (Al), copper (Cu), manganese (Mn), iron (Fe), nickel (Ni), thorium (Th), thallium (Tl), rubidium (Rb) and barium (Ba)) in tea samples were determined. The mean concentrations of As, Cd, Cr, Hg, Pb, Zn, Al, Cu, Mn, Fe, Ni, Th, Tl, Rb and Ba were in the range of 0.02-0.61, 0.008-0.126, 0.09-1.12, 0.001-0.012, 0.07-1.62, 19.5-73.2, 170-2100, 5.9-43.3, 228-2040, 60-337, 2.09-17.95, 0.002-0.08, 0.004-0.409, 0-150.50 and 3.1-41.2 µg/g, respectively, which were all lower than the maximum permissible limits stipulated by China (NY/T 288-2012, NY 659-2003). The target hazard quotients of each heavy metal were lower than one, and the combined risk hazard index of all heavy metals for adults was in the range of 0.10-0.85; therefore, there was no significant carcinogenic health risks to tea drinking consumers under the current dietary intake. Significant differences were found in the content of trace elements (Zn, Cu, Fe, Ni, Th, Tl, Rb and Ba) (p < 0.05); however, no significant differences were found in the content of macroelements (P, K, Ca and Mg) and trace metals (As, Cd, Cr, Hg, Pb, Al and Mn) in teas from different regions. Therefore, the region did not affect the heavy metal exposure risk. Correlation coefficient and principal component analyses were performed to determine the source of the elements. Three principal factors were obtained: factor 1 was positively related to Ca, Mg, As, Cd, Cr, Hg, Pb, Al, Mn, Fe and Th (32.63%); factor 2 to P, Zn, Cu and Ni (18.64%) and factor 3 to K and Rb (10.10%). Thus, the elements in the same factor might originate from the same source. This study provides an essential basis to understand the variance and potential risks of different elements in tea from different regions of China.

Potential health risk assessment, spatio-temporal hydrochemistry and groundwater quality of Yamuna river basin, Northern India.

Groundwater which is an essential source of freshwater for various domestic, agricultural, industrial applications is facing a severe deterioration in quality due to demographic pressure and intense industrial activities. Present study appraises the influence of human induced activities on groundwater quality of Agra-Firozabad industrial belts of Western Uttar Pradesh, Yamuna basin, India. The maximum concentrations of metals and anions found during pre and post monsoon are as follows: Lead 0.302; 0.086, calcium 672; 1260, magnesium 215; 16.8, cadmium 0.0; 0.066, chromium 0.016; 0.005, manganese 0.340; 0.076, nickel 0.044; 0.028, sulfate 514; 286, nitrate 66.7; 3.56 and fluoride 1.17; 2.02 mg/L respectively. Based on results of Water Quality Index, groundwater samples were classified under 'Poor water' category in 34.2% and 52.63% during pre and post-monsoon period, respectively. Accordingly, higher concentrations of bicarbonate and sulfate might have attributed to excess hardness, instrumental in making it unsuitable for industrial usage. However, values of Percent Sodium, Sodium Adsorption Ratio, Magnesium Hazard and Permeability Index signified that groundwater from majority of locations was fit for agricultural use. Health risk assessment studies revealed that children consuming polluted water were affected more as compared to adults. Timely action and strict compliance of regulation is recommended towards groundwater management for defined usage to avert severe health effects and to meet sustainable development goals.

Hydrogeochemistry and groundwater quality assessment in Ambagarh Chowki, Chhattisgarh, India.

The current study was focused on hydrogeochemistry of Ambagarh chowki groundwater. The main aim of the study was to evaluate the water quality for drinking and irrigation uses, hydrogeochemistry of groundwater. For this purpose, various physicochemical parameters like pH, electrical conductivity (EC), total hardness (TH), chloride (Cl-), fluoride (F-), calcium (Ca2+), magnesium (Mg2+), sodium (Na+), potassium (K+), bicarbonate (HCO3-), and sulfate (SO42-) were analyzed. The major dominating ions in groundwater was found as cation Ca2+ > Mg2+ > Na+ > K+ and as anions in order of HCO3- > Cl- > SO42- > F-. The pH of sampled groundwater was ranged from neutral to alkaline in nature (7.0-8.8). Among, all-analyzed parameters in groundwater were safe for drinking purpose except few ions and bicarbonate content was also exceeding the permissible limit which was not suitable for drinking purpose. The potential health hazard element fluoride was varied from 0.1 to 2.2 mg/l and positively associated with the pH, Na+, and HCO3- content in groundwater. The drinking water quality index (WQI) was fluctuated between 12.22 and 185.56 and reported that most of the groundwater was suitable for drinking purpose except only one sample was unsuitable for drinking. Irrigation water quality assessment of the area was performed by evaluating as sodium adsorption ratio (SAR), permeability index (PI), Kelly ratio (KR), magnesium hazard ratio (MHR), percent sodium (%Na), potential salinity (PS), and residual sodium carbonate (RSC). Whereas most of the groundwater were good and suitable for irrigation use excluding PI (3.70%), MHR (40.74%), RSC (22.22%) and PS (7.41%) were unsuitable for continuous irrigation. Hydrogeochemistry of groundwater evaluated with correlation, Piper, Gibbs, and other geochemical analysis. The Piper trilinear diagram reflects the Ca (Mg)-HCO3- type water was mainly contributed approximately 90% of entire sampled groundwater. The different ions in groundwater were originated from the rock water interaction through silicate and carbonate weathering of minerals.

Spatiotemporal assessment of groundwater quality in the Central Ganga Plain, India, using multivariate statistical tools.

In the present study, the water quality status of the Sadar block in Pratapgarh district of Uttar Pradesh, India, was calculated by Water Pollution Index (WPI) using 15 groundwater quality parameters (pH, turbidity, EC (electric conductivity), TDS (total dissolved solids), salinity, total hardness, Ca2+, K+, Mg2+, Na+, Cl-, F-, SO42-, HCO3-, and NO3-) at 40 different study locations. It is found that 10%, 25%, and 65%, of samples, fall under the good, moderately polluted, and highly polluted category, respectively. Irrigation suitability of groundwater has also been evaluated by using irrigation suitability parameters, i.e., Sodium Absorption Ratio (SAR), Residual Sodium Carbonate (RSC), Permeability Index (PI), Kelly Ratio (KR), Percentage Sodium (% Na), and Magnesium Hazards (MH). Based on the analysis, it was determined that most of the samples were suitable for irrigation in the area. Irrigation practices are found to be unsuitable for Kelly's ratio of 37.5%, MH 60%, and RSC 55% samples. WPI and Pearson's correlation matrix (PCA) have suggested a significant linear relationship among the water quality parameters based on the test results. The Gibbs plot indicates that the majority of samples fall under the "evaporation dominance" category while the rest fall under the "rock weathering dominance" suggesting that the complex geochemical mechanisms are active in the study area. This study would be very helpful to government authorities and it would aid them to suggest alternate drinking water resources in affected areas.

Water quality assessment of the Karasu River (Turkey) using various indices, multivariate statistics and APCS-MLR model.

Determining the water quality status of a river and accurately identifying potential pollution sources threatening the river are pillars in effective control of pollution and sustainable water management. In this study, water quality indices, multivariate statistics and absolute principal component score-multiple linear regression (APCS-MLR) were applied to evaluate the water quality of the Karasu River, the main tributary of the Euphrates River (Turkey). For this, 19 water quality variables were monitored monthly at eight stations along the river during one year. Based on the mean dissolved oxygen (DO), electrical conductivity (EC), nitrate-nitrogen (NO3-N), orthophosphate-phosphorus (PO4-P), total phosphorus (TP), ammonium-nitrogen (NH4-N), chemical oxygen demand (COD) and total nitrogen (TN) levels, most stations of the river had "very good" water status according to surface water quality criteria. Spatial cluster analysis (CA) divided eight stations into three regions as clean region, moderate clean region and very clean region. The mean values of Nutrient Pollution Index indicated that the river was "no polluted". Similarly, Water Quality Index and Organic Pollution Index values indicated that the river water quality was between "good" and "excellent". A minimum water quality index (WQImin) consisted of ten crucial parameters was not significantly different with the WQI based on all the 17 parameters. Discriminant analysis (DA) results showed that water temperature (WT), EC, chlorophyll-a (Chl-a), potassium (K), calcium (Ca), NO3-N and COD are the variables responsible for temporal changes, while WT, total dissolves solids (TDS), Chl-a, K, magnesium (Mg), Ca, NH4-N and COD are the variables responsible for spatial changes in the river water quality. Principal component analysis/factor analysis (PCA/FA) identified four potential sources, including anthropogenic, natural, seasonal and phytoplankton. Source apportionment in the APCS-MLR model revealed that seasonal and anthropogenic sources contributed 35.2% and 25.5% to river water quality parameters, respectively, followed by phytoplankton (21.4%) and natural sources (17.9%).

Groundwater quality assessment and modeling utilizing water quality index and GIS in Kabul Basin, Afghanistan.

Groundwater stands as a unique source of water supply in Kabul city, Afghanistan. In this investigation, 35 samples of groundwater were comprehensively analyzed to determine its hydrogeochemical characterizations, quality, water types, and its acceptability as drinking sources. A portable digital multiparameter instrument (LAB MAN Scientific instrument) was used to measure the total dissolved solids (TDS), hydrogen potential (pH), and electrical conductivity (EC). Total hardness, chloride, and bicarbonate were examined via a titrimetric approach. Sodium, calcium, magnesium, and potassium concentrations were measured with a flame photometer. Fluoride was determined by using a digital portable multiparameter. UV-VIS spectrophotometers were employed to count sulfate and nitrate concentrations. The distribution pattern of measured parameters and the Water Quality Index (WQI) in groundwater were spatially modeled utilizing the ArcGIS tool. The findings provide insight into the main anions and cations, which are found in ascending sequence F < NO3 < SO4 < Cl < HCO3 and K < Ca < Na < Mg, respectively. Based on the measurements of ion concentrations, bicarbonate (71.4%), chloride (14.28%), nitrate (2.85%), magnesium (80%), sodium (82.85%), calcium (5.71%), and potassium (17.14%) were all determined to be over the World Health Organization (WHO) limits of drinking water. Using the Piper trilinear diagram, two significant hydrochemical facies (CaNaHCO3 and NaHCO3) were discovered. Based on the mathematical model of WQI outputs, 88.57% of the research region has excellent to good water, whereas 11.43% has poor to very poor water.

Assessment of seminal calcium and magnesium levels in infertile men with varicocele before and after varicocelectomy.

BACKGROUND: Trace elements perform a vital role in all stages of human physiology, as well as reproduction. OBJECTIVE: This study aimed to assess seminal calcium (Ca) and magnesium (Mg) in infertile men associated with varicocele (Vx). MATERIALS AND METHODS: Overall, 50 men were divided into two groups: fertile men (n = 20) and infertile men who were scheduled for Vx surgical repair (n = 30). Exclusion criteria were as follows: azoospermia, smoking, leukocytospermia, and consumption of Ca and/or Mg supplements. All cases were subjected to history taking and clinical examination. Semen analysis and assessment of seminal Ca and Mg by the colorimetric method were carried out for all cases at the base point and 3 months postvaricocelectomy. RESULTS: Generally, the mean seminal Ca and Mg levels demonstrated significant decreases in infertile men with Vx compared with the healthy fertile men linked to higher Vx grade as well as Vx bilaterality. These seminal decreases demonstrated significant increases after Vx surgical repair. Collectively, seminal Ca and Mg levels showed a significant positive correlation (r = 0.665, p= 0.001). Besides, seminal Ca, Mg levels, and Ca/Mg ratio showed significant positive correlation with sperm concentration (r = 0.479, p = 0.001; r = 0.541, p = 0.001; r = 0.282, p = 0.001, respectively), sperm motility percentage (r = 0.493, p = 0.001; r = 0.477, p = 0.001; r = 0.353, P = 0.001, respectively), and sperm normal forms percentage (r = 0.578, p = 0.001; r = 0.520, p = 0.001; r = 0.430, p = 0.001, respectively). DISCUSSION AND CONCLUSION: Seminal Ca and Mg levels and Ca/Mg ratio are significantly decreased in infertile men associated with Vx compared with fertile men with significant increases after varicocelectomy.

Geochemical and mineralogical assessment of sedimentary limestone mine waste and potential for mineral carbonation.

This paper attempts to evaluate the mineralogical and chemical composition of sedimentary limestone mine waste alongside its mineral carbonation potential. The limestone mine wastes were recovered as the waste materials after mining and crushing processes and were analyzed for mineral, major and trace metal elements. The major mineral composition discovered was calcite (CaCO3) and dolomite [CaMg(CO3)2], alongside other minerals such as bustamite [(Ca,Mn)SiO3] and akermanite (Ca2MgSi2O7). Calcium oxide constituted the greatest composition of major oxide components of between 72 and 82%. The presence of CaO facilitated the transformation of carbon dioxide into carbonate form, suggesting potential mineral carbonation of the mine waste material. Geochemical assessment indicated that mean metal(loid) concentrations were found in the order of Al > Fe > Sr > Pb > Mn > Zn > As > Cd > Cu > Ni > Cr > Co in which Cd, Pb and As exceeded some regulatory guideline values. Ecological risk assessment demonstrated that the mine wastes were majorly influenced by Cd as being classified having moderate risk. Geochemical indices depicted that Cd was moderately accumulated and highly enriched in some of the mine waste deposited areas. In conclusion, the limestone mine waste material has the potential for sequestering CO2; however, the presence of some trace metals could be another important aspect that needs to be considered. Therefore, it has been shown that limestone mine waste can be regarded as a valuable feedstock for mineral carbonation process. Despite this, the presence of metal(loid) elements should be of another concern to minimize potential ecological implication due to recovery of this waste material.

A snapshot of Late Mesolithic life through death: An appraisal of the lithic and osseous grave goods from the Castelnovian burial of Mondeval de Sora (Dolomites, Italy).

The Late Mesolithic in Southern Europe is dated to the 7th and the first part of the 6th millennia BCE and is marked by profound changes which are mostly evident in the technical know-how and tool-kit of the last hunter-fisher-gatherer societies. The significance of this phase also relates to the fact that it precedes the Early Neolithic, another period of major transformations of human societies. Nonetheless, the Late Mesolithic still remains a poorly known age in this area. A burial discovered at Mondeval de Sora (Northern Italy) in 1987, represents a unique window into this period. In this paper, we provide a detailed analysis of more than 50 lithic and osseous artifacts associated with this burial. We highlight important contextual data regarding the techno-economic dimension and the notion of personal burial possessions. Based on the association and location of some items, we propose a new interpretation of the social status of this individual and the possible impact of technological innovation on the social organization and symbolic sphere of Late Mesolithic groups.

The assessment of intracellular magnesium: different strategies to answer different questions.

The role of magnesium in cell metabolism is complex and still not completely clarified. Although magnesium has been shown to modulate many phenomena in cells, its intracellular distribution and subcellular compartmentalization have not yet elucidated in detail, mainly as a consequence of the inadequacy of analytical techniques. The method usually employed to quantify total magnesium in cells or tissue are F-AAS or more sensitive techniques as graphite furnace AAS and inductively coupled plasma mass spectroscopy (MS). Thanks to the development of new specific fluorescent dyes, several progresses have been made in the comprehension of the fundamental biological process at the cellular and sub-cellular level. Moreover, the biological function of a chemical element in cells does not only require the determination of its intracellular quantity but also the spatial distribution of its concentration. Most of Mg2+-sensitive fluorescent dyes detect only the free metal ions, precluding the possibility of identifying the total pool of Mg. This review aims at giving an overview on different techniques focusing on two approaches to quantify total Mg in a small cell population or in single cells: i) Indirect Mg detection, label-based methods that represent the best choice to quantify the elemental concentration on a large cell population; ii) direct Mg detection (label-free), Synchrotron-based x-ray microscopy techniques that offer the possibility of achieving a detailed map of the intracellular concentration of a specific chemical element on single cell.

Assessment of physico-chemical changes in UHT milk during storage at different temperatures.

This research communication describes enzymatic and physico-chemical changes during storage of UHT milk. The UHT milk sample was stored at 5 and 30°C for 4 months and analyzed regularly at intervals of one month. During storage of UHT milk, there was a significant (P < 0.001) increase in non-protein nitrogen, non-casein nitrogen, soluble calcium, soluble magnesium and proteolysis, while a significant (P < 0.001) decrease in pH was observed. There was a slight change in the particle size and zeta potential of casein micelles. Changes were more pronounced in milk samples stored at 30°C than in those stored at 5°C. During storage, there occurred changes in pH, viscosity, salt balance and nitrogenous components which adversely affected quality. It was concluded that the proteolysis led to the acidification which had a destabilizing effect on the milk.

DFT/MRCI assessment of the excited-state interplay in a coumarin-schiff Mg2+ fluorescent sensor.

Fluorescent sensors with selectivity and sensitivity to metal ions are an active field in supramolecular chemistry for biochemical, analytical, and environmental problems. Mg2+ is one of the most abundant divalent ions in the cell, and it plays a critical role in many biological processes. Coumarin-based sensors are widely used as desirable fluorophore and binding moieties showing a remarkable sensitivity and fluorometric enhancement for Mg2+ . In this work, density functional theory/multireference configuration interaction (DFT/MRCI) calculations were performed in order to understand the sensing behavior of the organic fluorescent sensor 7-hydroxy-4-methyl-8-((2-(pyridin-2-yl)hydrazono)methyl)-2H-chromen-2-one (PyHC) in ethanol to solvated Mg2+ ions. The computed optical properties reproduce well-reported experimental data. Our results suggest that after photoexcitation of the free PyHC, a photo-induced electron transfer (PET) mechanism may compete with the fluorescence decay to the ground state. In contrast, this PET channel is no longer available in the complex with Mg2+ making the emissive decay more efficient. © 2019 Wiley Periodicals, Inc.

TYPE TESTING OF LiF:Mg,Cu,P (TLD-100H) WHOLE-BODY DOSEMETERS FOR THE ASSESSMENT OF Hp(10) AND Hp(0.07).

In this work, the initial results of the type testing of the LiF:Mg,Cu,P (TLD-100H) whole-body personal dosemeters are presented. An assessment of reproducibility, linearity of the response, the residual signal as a function of the dose, energy and angular dependence of the response was performed. In general, the dosemeters show good reproducibility for different dose values and a linear behaviour for a range between 0.1 and 300 mSv. The detection limits obtained are lower than 50 µSv. The system presents a good energy and angular response for different radiation qualities.

Tear electrolyte assessment of diabetic patients in Southern Nigeria.

BACKGROUND: Tears are a critical body extracellular fluid coating the surface epithelial cells of the cornea and conjunctiva, and providing the optically smooth surface necessary for refraction of light onto the retina. The biological and chemical properties of tears change in response to systemic disease. OBJECTIVES: This study assessed the concentration of calcium, magnesium and phosphate levels in tears of diabetics. METHODS: A comparative cross-sectional study involving twenty diabetics visiting Department for Health Services, University of Benin and forty non-diabetics within the University between 35 to 65 years participated in the study. Calcium, magnesium and phosphorous were analysed in tears sample collected with 75mm glass capillary tubes. RESULTS: The fasting blood sugar (FBS) and age of diabetic patients was 7.48±1.88mmol/l and 56.75±5.82years and non-diabetics was 4.83±0.52mmol/l and 53.58±6.16years respectively. Magnesium showed no differences (P<0.05) between diabetics (0.76±0.45mmol/l) and non-diabetics (0.93±0.59mmol/l). Calcium was elevated (P=0.041) and phosphate (P=0.044) was decreased in diabetics (3.14±1.65mmol/l and 0.074±0.058mmol/l) than non-diabetics (2.41±1.05mmol/l and 0.11±0.081mmol/l). CONCLUSION: This study concluded that being diabetic can affect the levels of some tear electrolytes in the tear fluid which may lead to an increased risk of diabetic ocular complications.

Ethnic Differences in Magnesium Intake in U.S. Older Adults: Findings from NHANES 2005⁻2016.

Magnesium plays a crucial role in hundreds of bodily processes relevant to aging, but consumption of dietary magnesium intake has been shown to be inadequate in a large proportion of older adults. Identifying groups at risk of low magnesium intake is important for informing targeted advice. Using data from the National Health and Nutrition Examination Survey (NHANES) 2005⁻2016, we examined the association between ethnicity (Caucasian/African American/Hispanic/other) and magnesium intake in a large representative sample of U.S. older adults (≥65 y, n = 5682, mean (SD) 72.9 (0.10) y). Analyses adjusted for total energy intake and a range of relevant covariates. Overall, 83.3% of participants were not meeting the recommended level of dietary magnesium intake, ranging from 78.1% of other ethnic groups to 90.6% of African Americans. In the fully adjusted model, magnesium intake was lower among African American older adults (-13.0 mg/d, 95% CI: -18.8 to -7.2), and higher among Hispanics (14.0 mg/d, 95% CI: 7.5 to 20.5) and those from other ethnic groups (17.2, 95% CI: 3.8 to 30.5) compared with Caucasian older adults. These results highlight the need for targeted interventions to increase magnesium intake in U.S. older adults, with a focus on African Americans, in order to reduce the burden of morbidity and ethnic inequalities in health in later life.

Assessment of the Bioaccessibility of Trace Elements in Cat's Claw Teas by In Vitro Simulated Gastrointestinal Digestion Using FAAS.

The aim of this study was to evaluate the bioaccessibility of Ca, Fe, Mg, Mn, and Zn in cat's claw plant teas through in vitro gastrointestinal digestion with gastric and intestinal juice solutions. The total concentrations and bioaccessible fractions of Ca, Fe, Mg, Mn, and Zn were measured by flame atomic absorption spectrometry (FAAS). The results obtained showed that Zn was the most bioaccessible element in the teas, contributing a mean of 57.9% by infusion and 62.5% by decoction. Among macroelements, the Ca was less bioaccessible with 17.4% recovery. The bioavailability assessment revealed that daily intake of 200 ml of cat's claw teas cover about 1.0% of manganese RDA.