Effect of changes in food groups intake on magnesium, zinc, copper, and selenium serum levels during 2 years of dietary intervention.

BACKGROUND: Essential elements in serum are related to specific changes in food groups intake. OBJECTIVE: To address the effect of 2-year food intake changes in an intervention study on serum concentrations of magnesium, zinc, copper, and selenium. METHOD: Two hundred thirty-one participants, a subgroup of the Dietary Intervention Randomized Control Trial (DIRECT) study (age = 52 years; body mass index = 32.8 kg/m(2); 85% males) randomized to low-fat, Mediterranean, or low-carbohydrate diets in a 2-year dietary intervention trial were followed for serum concentrations determined using inductively coupled plasma-mass spectrometry. Changes in the intake of 11 food groups were evaluated by food frequency questionnaires. RESULTS: Using multivariate regression models, adjusted for age, sex, baseline body weight (kg), and changes in intakes of 11 food groups (g/d), at 12 months, serum element elevations were observed mainly in the low-carbohydrate group: selenium, by increasing consumption of fats and oils (ß = 0.415, p = 0.009) and legumes (ß = 0.183, p = 0.010) and decreasing fruit intake (ß = -0.438, p = 0.030); copper, by increasing consumption of legumes (ß = 0.453, p = 0.018) and dairy products (ß = 0.320, p = 0.039); magnesium by increasing fish consumption (ß = 0.374, p = 0.042) in the low-carbohydrate group and in the entire study population (ß = 0.237, p = 0.016); and zinc exclusively in the low-fat group by decreasing consumption of fats and oils (ß = -0.575, p = 0.022). At 24 months, serum elements were elevated mainly in the low-fat diet group, mostly by decreasing intake of snacks, sweets, and cakes: zinc (ß = -0.570, p = 0.027), copper (ß = -0.649, p = 0.012), and selenium (ß = -0.943, p < 0.001). Also in this group, magnesium levels were elevated by increasing vegetable intake (ß = 0.395, p = 0.041), copper by increasing fruit intake (ß = 0.375, p = 0.025), and selenium by increasing consumption of bread, pasta, and cereals (ß = 0.751, p = 0.011). The entire group, further adjusted to assigned diet type, increased selenium (ß = 0.294, p = 0.004) and copper (ß = 0.220, p = 0.038) by increasing consumption of bread, pasta, and cereals; selenium level was also predicted by decreasing consumption of snacks, sweets, and cakes (ß = -0.256, p = 0.014). Introducing energy expenditure, expressed in metabolic equivalents (MET = 1 kcal·kg(-1)·h(-1)), as an additional variable emphasized the negative effect of sweets and cakes on increasing serum concentrations of zinc, copper, and selenium after 24 months (ß = -0.549, p = 0.021; ß = -0.669, p = 0.012; ß = -0.982, p < 0.001, respectively), especially in the low-fat diet group. No significant associations between changes in food groups intake and the 4 elements were found in the Mediterranean diet group. CONCLUSIONS: During this 2-year intervention, serum concentrations of 4 essential elements were associated with a diversity of food group intake patterns. Comprehensive predictors for elevating zinc, copper, and selenium in serum included decreasing consumption of sweets and cakes while increasing consumption of bread, cereals, and pasta.

Biosorption of uranyl ions from aqueous solutions by soluble renewable polysaccharides.

Polysaccharides derived from natural sources have been offered as environment friendly sorbents for the adsorption of heavy metals. We present a simple technique to remove uranyl ions from aqueous solutions by using representative polysaccharides. The adsorption efficiency of UO22+ decreased in the following order: xanthan gum > kappa > iota/guar gum, for instance, the efficiencies after sorption of 30 min with 500 mg per L uranyl acetate and 0.03 g of the corresponding polysaccharide were: 89.7%, 85.2%, 79.1% and 77.1%. Lowering the acidity in the system decreased the sorption efficiency with all the polysaccharides, and reducing the ratio between the amount of uranyl ions and the amount of polysaccharide increased the sorption efficiencies, e.g., using 500 mg per L uranyl acetate and 0.05 g of the corresponding polysaccharide (xanthan gum, kappa, iota, guar gum) yielded after 30 min sorption efficiencies of 94.3%, 91.5%, 89.0% and 87.7%, respectively. FTIR, SEM-EDS and TGA analyses verified the presence of uranium in the polysaccharides and showed that the uranyl ions were interacting with the different functional groups. Moreover, the addition of uranyl ions to the polysaccharides caused a sharp decrease in viscometry measurements. In addition, the measurements showed that the addition of uranyl lowered both modules, G' and G'', and made the solution more liquid.

Selective Sorption of Heavy Metals by Renewable Polysaccharides.

Renewable and biodegradable polysaccharides have attracted interest for their wide applicability, among them their use as sorbents for heavy metal ions. Their high sorption capacity is due mainly to the acidic groups that populate the polysaccharide backbone, for example, carboxylic groups in alginate and sulfate ester groups in the iota and lambda carrageenans. In this study, these three polysaccharides were employed, alone or in different mixtures, to recover different heavy metal ions from aqueous solutions. All three polysaccharides were capable of adsorbing Eu3+, Sm3+, Er3+, or UO22+ and their mixtures, findings that were also confirmed using XPS, TGA, and FTIR analyses. In addition, the highest sorption yields of all the metal ions were obtained using alginate, alone or in mixtures. While the alginate with carboxylic and hydroxyl groups adsorbed different ions with the same selectivity, carrageenans with sulfate ester and hydroxyl groups exhibited higher adsorption selectivity for lanthanides than for uranyl, indicating that the activity of the sulfate ester groups toward trivalent and smaller ions was higher.

Insights on hydrogen spillover on carbonaceous supports.

Hydrogen spillover is important in solid-phase catalytic hydrogenation reactions, as well as in hydrogen storage and scavenging. The present study explores the nature of this phenomenon by examining the effects of hydrogen pressure and addition of carbonaceous additives, such as carbon nanotubes (CNT) and C60 fullerene, on hydrogenation reaction kinetics and its products distribution. For these purposes, a solid-phase hydrogenation reaction was studied, where 1,4-bis-(phenyl-ethynyl)benzene (PEB) was used as a hydrogen acceptor. To the best of our knowledge, this is the first study in which both the reaction kinetics and products distribution of the solid-phase organic hydrogen acceptor were analyzed. A demonstration of hydrogen spillover phenomenon was provided on the basis of the combined interpretation of kinetics and hydrogenated organic products distribution, under different reaction conditions. The results were explained in terms of hydrogen active species availability, distribution and relative migration distance of these species through the carbonaceous media. The insights into the hydrogen spillover chemistry obtained in this research allow for a better understanding of this phenomenon and its implementation in the future hydrogen storage and transportation, and hydrogen-generating devices, including safety aspects of all these applications.

Sniffing Bacteria with a Carbon-Dot Artificial Nose.

HIGHLIGHTS: Novel artificial nose based upon electrode-deposited carbon dots (C-dots). Significant selectivity and sensitivity determined by "polarity matching" between the C-dots and gas molecules. The C-dot artificial nose facilitates, for the first time, real-time, continuous monitoring of bacterial proliferation and discrimination among bacterial species, both between Gram-positive and Gram-negative bacteria and between specific strains. Machine learning algorithm furnishes excellent predictability both in the case of individual gases and for complex gas mixtures. Continuous, real-time monitoring and identification of bacteria through detection of microbially emitted volatile molecules are highly sought albeit elusive goals. We introduce an artificial nose for sensing and distinguishing vapor molecules, based upon recording the capacitance of interdigitated electrodes (IDEs) coated with carbon dots (C-dots) exhibiting different polarities. Exposure of the C-dot-IDEs to volatile molecules induced rapid capacitance changes that were intimately dependent upon the polarities of both gas molecules and the electrode-deposited C-dots. We deciphered the mechanism of capacitance transformations, specifically substitution of electrode-adsorbed water by gas molecules, with concomitant changes in capacitance related to both the polarity and dielectric constants of the vapor molecules tested. The C-dot-IDE gas sensor exhibited excellent selectivity, aided by application of machine learning algorithms. The capacitive C-dot-IDE sensor was employed to continuously monitor microbial proliferation, discriminating among bacteria through detection of distinctive "volatile compound fingerprint" for each bacterial species. The C-dot-IDE platform is robust, reusable, readily assembled from inexpensive building blocks and constitutes a versatile and powerful vehicle for gas sensing in general, bacterial monitoring in particular.

Thenoyltrifluoroacetone (TTA)-Carbon Dot/Aerogel Fluorescent Sensor for Lanthanide and Actinide Ions.

Contamination of groundwater with radioactive substances comprising actinides and lanthanides is a significant environmental hazard and thus the development of selective, sensitive, and easy-to-apply sensors for water-soluble actinide and lanthanide ions is highly sought. We constructed a new selective fluorescent sensor for UO2 2+, Sm3+, and Eu3+ based on a carbon dot (C-dot)-aerogel hybrid prepared through in situ carbonization of 2-thenoyltrifluoroacetone (TTA), a high-affinity heavy metal chelator. The TTA-C-dot-aerogel enabled the detection of UO2 2+ ions, which induced a significant red fluorescence shift, whereas Eu3+ and particularly Sm3+ ions gave rise to pronounced fluorescence quenching. Importantly, the lanthanide/actinide ion-selective TTA-C-dots could be synthesized only in situ inside the aerogel pores, indicating the crucial role of the aerogel host matrix both in enabling the formation of the C-dots and in promoting the adsorption and interactions of the lanthanide and actinide metal ions with the embedded C-dots.

Lead concentrates in ovarian follicle compromises pregnancy.

Following absorption, lead can concentrate in bodily compartments where it disrupts cellular processes and can result in detrimental health consequences. The concentration and impact of lead within follicular fluid has not been characterized and we used inductively coupled plasma mass spectroscopy (ICP-MS) to determine lead levels in blood and follicular fluid from nine patients undergoing in vitro fertilization (IVF) treatment. Lead levels within follicular fluid were found to be significantly higher in non-pregnant patients compared to pregnant patients suggesting that elevated concentrations of the environmental toxicant lead adversely affect female reproduction.

Elements in maternal blood and amniotic fluid determined by ICP-MS.

OBJECTIVE: Knowledge about levels of toxic and non-toxic elements in amniotic fluid is limited. The aims of this study were: (1) to measure levels of trace elements Cu, Fe, Zn, B, Sr and Co in amniotic fluid and maternal serum during second trimester of pregnancy; and (2) to determine what correlations exists between elements levels in amniotic fluid and maternal serum. METHODS: The levels of, iron, copper, zinc, cobalt, strontium and boron were measured in blood and amniotic fluid during genetic amniocentesis using inductively coupled plasma mass spectrometry (ICP-MS). RESULTS: Concentrations of the elements: Fe, Cu, Zn, Co, Sr and B in amniotic fluid were significantly lower than in maternal blood. For iron, zinc, cobalt, strontium and boron there was a linear correlation between levels in amniotic fluid and maternal serum. CONCLUSIONS: The concentration of trace elements in amniotic fluid was found to be lower than maternal serum and linearly correlated to its level.

Trace elements' concentrations in maternal and umbilical cord plasma at term gestation: a comparison between active labor and elective cesarean delivery.

OBJECTIVE: Trace elements are minerals required in minute quantities to maintain proper physical functioning. The role of trace elements in the process of parturition is poorly understood. This study was aimed to determine levels of trace elements' concentration in maternal plasma and umbilical venous and arterial plasma at term during active labor vs elective cesarean delivery (CD). STUDY DESIGN: A prospective case-control study was conducted. Forty healthy parturients in active labor at term with their newborns were compared to 40 healthy parturients matched for maternal age, parity, and gestational age, who delivered by elective CD (before commencement of labor). Samples of maternal venous blood and umbilical cord arterial and venous blood were drawn immediately following delivery. Trace elements' concentrations were measured using the inductively coupled plasma mass spectrometer (ICP-MS). RESULTS: Significant higher levels of manganese (Mn) and selenium were found in maternal venous plasma during active labor vs elective CD. Magnesium (Mg) levels were significantly higher in maternal venous blood during elective CD compared to active labor. Umbilical cord artery levels of Mg, Mn, and zinc (Zn) were significantly higher in active term labor vs elective CD. Also, significant higher levels of copper and Zn were found in umbilical cord vein between active labor and elective CD. CONCLUSION: Trace elements' concentrations differ significantly in fetal blood during active labor vs elective CD. Hence, trace elements may play a crucial role in the process of human parturition.

Severe pre-eclampsia is associated with abnormal trace elements concentrations in maternal and fetal blood.

OBJECTIVE: The study was aimed to compare trace elements concentrations in women with and without severe pre-eclampsia (PE). METHODS: A prospective case-control study was conducted comparing 43 parturients with severe PE (who received magnesium sulfate [MgSO4]) and 80 healthy parturients and their newborns, matched for gestational age and mode of delivery. Inductively coupled plasma mass spectrometry (ICPMS) was used for the determination of zinc (Zn), copper (Cu), selenium (Se) and magnesium (Mg) levels in maternal as well as arterial and venous umbilical cord serum. RESULTS: Zn levels (µg/L) were significantly higher in fetal arterial and venous blood of the PE group (947.3 ± 42.5 vs. 543.1 ± 226, 911.1 ± 220.2 vs. 422.4 ± 145, p < 0.001; respectively). Se levels (µg/L) were significantly lower in maternal and fetal arterial and venous cord blood of the PE group (98.6 ± 24.2, 110.7 ± 19.4, 82 ± 17.8 vs. 111.6 ± 17.6, 82.1 ± 17.4 vs. 107.1 ± 25.7, p < 0.001; respectively). Cu levels (µg/L) were significantly lower in fetal arterial and venous cord blood (581.6 ± 367.4 vs. 949 ± 788.8, p = 0.022, 608.3 ± 418.1 vs. 866.9 ± 812.6, p = 0.001 respectively) but higher in maternal blood (2264.6 ± 751.7 vs. 1048 ± 851.1, p < 0.001). These differences remained significant while controlling for the mode of delivery. Mg levels were significantly higher in the PE group as compared with the control group. CONCLUSIONS: Severe PE is associated with abnormal concentrations of Zn, Cu and Se. Therefore, trace elements may have a crucial role in the pathogenesis of severe PE.

Trace element concentrations in follicular fluid of small follicles differ from those in blood serum, and may represent long-term exposure.

OBJECTIVE: To determine the levels of elements in follicular fluid (FF) of patients undergoing IVF and evaluate the relationship between the concentration of elements in FF, follicular volume, and blood. DESIGN: Prospective blinded study. SETTING: University-based IVF center. PATIENT(S): Follicular fluid/blood samples from 6/3 patients, respectively, undergoing IVF. INTERVENTION(S): Single follicular aspirations of 33 follicles were performed. Blood samples ( approximately 5 mL) were drawn at the time of oocyte retrieval from 3/6 patients only. The concentrations 26 elements were measured by inductively coupled plasma mass spectroscopy. MAIN OUTCOME MEASURE(S): Trace elements concentrations in follicular fluid and blood. RESULT(S): [1] Calcium and magnesium were the most abundant, followed by Cu, Zn, Fe, Cr, Rb. The elements V, Sr, Se, B, As, Pb, Al, Mo, Mn, and Cs were found in trace amounts. The elements Li, Be, Ag, Cd, Ba, Ti, Bi, U were not detected. [2] Element concentrations in small follicles frequently differed from those of large follicles. [3] Element concentrations in large follicles more closely resembled those in blood. CONCLUSION(S): Concentrations of elements in FF of small follicles can differ from those of large follicles in the same woman and from those of blood serum. When follicles grow they become filled with fluid of an elemental composition similar to blood. Concentrations of elements in small follicles may represent longer term element exposure, whereas those of growing follicles represents the coincident blood concentrations.