Growth and characterization of non-linear optical crystal Cd3Zn3B4O12

Cd₃Zn₃B₄O₁₂ polycrystals were synthesized by solid-state and wet chemical reaction methods. Cd₃Zn₃B₄O₁₂ single crystals with millimeter grade were grown from the self-flux B₂O₃ (Cd:Zn:B = 1:1:1.5); and larger crystals were obtained from the PbO-0.85PbF₂ fluxes easily. As-grown crystals were characterized by differential scanning calorimetry and thermogravimetric, X-ray diffraction, infrared and Raman spectral analysis, respectively. The non-linear optical coefficient of the Cd₃Zn₃B₄O₁₂ crystal is 2.6 times as large as that of KH₂PO₄ crystal. Chemical etching shows that this crystal is very stable in neutral solution and not hygroscopic in air at room temperature.     

Synthesis of layered sodium lanthanum selenide through ion exchange reactions

Layered hexagonal KLaSe2 (α-NaFeO₂-type) was synthesized using the reactive flux method and analyzed by powder XRD to determine its lattice constants (space group R-3m, a = 4.40508(5) Å, c = 22.7838(5) Å). NaLaSe₂, which normally crystallizes as a disordered rock salt structure with mixed Na+/La + 3 sites, was synthesized through a solid state ion exchange reaction at 585 °C from a 1:3 molar ratio mixture of KLaSe₂:NaI. The product of this reaction was hexagonally layered NaLaSe₂ (space group R-3m, a = 4.3497(3) Å, c = 20.808(2) Å) isostructural to KLaSe₂. This product was analyzed by comparison with members of the set of solid solutions Na_(1−x)K_(x)LaSe₂ to confirm that the extent ion exchange in this reaction was complete. Cubic (disordered) NaLaSe₂ was also reacted with KI to yield the poorly crystalline hexagonally layered product with the approximate formula Na_0.79K_0.21LaSe₂.     

Role of elicitation on the health-promoting properties of kidney bean sprouts

The influence of germination of kidney beans for 4, 6 and 8 days in different elicitors (ascorbic acid, folic acid, glutamic acid, glutamic acid/chitosan and lactic acid/chitosan) on the production of health-promoting ingredients was studied. Sprouts were characterized according to their protein profile, soluble phenolic compounds (SPC) and γ-aminobutyric acid (GABA) content. Additionally, the antioxidant and angiotensin-converting enzyme (ACE) inhibition activities of aqueous extracts from kidney bean elicited sprouts were determined. Elicitation by glutamic acid for 8 days led to the highest SPC and GABA accumulation in kidney bean sprouts and their extracts were selected based on their highest phytochemical content. These extracts also showed remarkable antioxidant and ACE-inhibitory activities. The IC₅₀ for ACE inhibition of glutamic acid-extracts increases 89-fold after the in-vitro gastrointestinal digestion. These results will contribute not only to improving the health-promoting potential of kidney bean sprouts but also to obtaining ingredients which might reduce oxidative stress and hypertension.     

Morphology-controlled hydrothermal synthesis of MnCO3 hierarchical superstructures with Schiff base as stabilizer

MnCO₃ with hierarchical superstructures such as chrysanthemum, straw-bundle, dumbbell and sphere-like were synthesized in water/ethanol system under environment-friendly hydrothermal condition. In the synthesis process, the CO₂ in atmosphere was used as the source of carbonate ions and Schiff base was used as shape guiding-agent. The different superstructures of MnCO₃ could be obtained by controlling the hydrothermal temperature, the molar ratio of manganous ions to the Schiff base, or the volume ratio of water to ethanol. A tentative growth mechanism for the generation of MnCO₃ superstructures was proposed based on the rod–dumbbell–sphere model. Furthermore, the MnCO₃ as precursor could be further successfully transferred to Mn₂O₃ microstructure after heating in the atmosphere at 500 °C, and the morphology of the Mn₂O₃ was directly determined by that of the MnCO₃ precursor.     

Determination of selected dichloroanilines and phthalates in lyophilised mussels samples with ultra-high performance liquid chromatography-tandem mass spectrometry after QuEChERS clean-up

ABSTRACT

Mussels, a marine filter organism, constitute a food product and an established sentinel organism for marine pollution. An analytical method following a QuEChERS extraction and clean-up protocol has been developed for the determination of phthalic acid esters (PAE), including di-n-octyl phthalate (DnOP), di-(2-ethyl hexyl) phthalate (DEHP), butyl benzyl phthalate (BBP), di-methyl phthalate (DMP) and di-n-butyl phthalate (DnBP), as well as 3,4-dichloroaniline and 3,5-dichloroaniline in lyophilised mussels samples. A gradient elution program starting from 40% A (methanol-0.1% formic acid) – 60% B (H₂O-0.1% formic acid) up to 100% A was applied, with a total duration of 15 min, at a flow rate of 200 μL min^?1 using a 1.8 μm particle size C18 analytical column. All target analytes were detected with a triple quadrupole MS, using electrospray ionisation (ESI) in positive ionisation mode, in SRM mode under optimised conditions. Sample preparation consisted of lyophilisation of the mussels sample and grinding, followed by a QuEChERS (Quick, Easy, Cheap, Effective, Rugged, Safe) protocol. Among the different dispersants evaluated for sample clean-up effectiveness, primary secondary amine (PSA) was found to be the most efficient. Results indicated good chromatographic separation, fast sample preparation procedure, low LODs and LOQs, good trueness expressed as recovery and good precision as evaluated by RSD. In the mussels samples examined DEHP was the most abundant PAE, reaching a maximal concentration of 280 μg/kg of lyophilised weight whereas the levels of DnBP were at approximately 36% of the legal migration limit in foods determined by the EU.     

Antioxidant properties of garden strawberry leaf extract and its effect on fish oil oxidation

The present study characterises garden strawberry leaf extract and reports its effect on shelf life and quality characteristics of fish oil. Radical scavenging capacity of the extract in DPPH^? and ABTS^?+ assays was equivalent to 1207 and 1579 μmol g^?1 of trolox equivalents, respectively, total phenolic content was 257 mg g^?1 of gallic acid equivalents. Phenolic and volatile constituents were analysed by liquid chromatography/mass spectrometry (LC/MS) and gas chromatography/mass spectrometry (GC/MS). The extract was added to fish oil and its oxidation was followed during 42 days: peroxide, p‐anisidine values and hexanal concentration were lower in the samples with extract, particularly at the end of storage. The effect of extract on fatty acid composition was not significant, however the changes in the percentages of some individual acids were observed. Fish oil containing 5% of extract had lower levels of lipid oxidation in comparison to other samples. The results indicate that strawberry leaves could be a potential source of natural antioxidants.     

Overcharge protection effect and reaction mechanism of cyclohexylbenzene for lithium ion batteries

We studied the relationship between the structure of aromatic compounds and the overcharge protection effect, using cyclohexylbenzene, isopropylbenzene, and toluene as the overcharge protection agents. Cyclohexylbenzene proved to be the most effective overcharge protection agent among these aromatic compounds. The effect is enhanced using a higher concentration of cyclohexylbenzene and elevated temperatures. The reaction product of cyclohexylbenzene was analyzed using field desorption mass spectrometry to elucidate its reaction mechanism. The results suggested that some of the overcharge reaction products of CHB were more reactive than that of IPB, which is consistent with the better suppressing effect on overcharging of the active material in the positive electrode.     

Effects of postharvest UV‐C treatment on carotenoids and phenolic compounds of vine‐ripe tomatoes

Light red tomatoes were exposed to different doses of ultraviolet C (UV‐C) irradiation (1.0, 3.0 and 12.2 kJ m^?2). After treatment, the tomatoes were stored for 2 days at room temperature, and then analysed to determine the effect of irradiation on the main antioxidants, carotenoids and phenolic compounds and the results compared with the control samples. The lycopene content was found to have increased by 14% with respect to the control samples, while β‐carotene decreased. Cis‐isomers from lycopene also increased when the tomatoes were exposed to irradiation for more than 3 h. UV‐C irradiation also had a positive effect on total phenolic compounds; however, the same effect was not observed in the individually analysed phenolic compounds. While chlorogenic and ferulic acids increased in content, naringenin and rutin contents decreased. These results suggest that UV‐C irradiation of tomatoes could improve the beneficial effect of red tomatoes for human health by increasing the levels of certain bioactive compounds; it could also be used to obtain higher content of bioavailability components, such as cis‐isomers from lycopene.     

Development of bismuth tellurium selenide nanoparticles for thermoelectric applications via a chemical synthetic process

Bismuth tellurium selenide (Bi₂Te_ySe_3−y) nanoparticles for thermoelectric applications are successfully prepared via a water-based chemical reaction under atmospheric conditions. The nanostructured compound is prepared using a complexing agent (ethylenediaminetetraacetic acid) and a reducing agent (ascorbic acid) to stabilize the bismuth precursor (Bi(NO₃)₃) in water and to favor the reaction with reduced sources of tellurium and selenium. The resulting powder is smaller than ca. 100 nm and has a crystalline structure corresponding to the rhombohedral Bi₂Te_2.7Se_0.3. The nanocrystalline powder is sintered via a spark plasma sintering process to obtain a sintered body composed of nano-sized grains. Important transport properties of the sintered body are measured to calculate its most important characteristic, the thermoelectric performance. The results demonstrate a relationship between the nanostructure of the sintered body and its thermal conductivity.     

Malolactic fermentation of Tempranillo wine: contribution of the lactic acid bacteria inoculation to sensory quality and chemical composition

Malolactic fermentation (MLF) of Tempranillo Rioja wines (Spain) inoculated with two lactic acid bacteria (LAB) strains were studied and compared with spontaneous MLF. Inoculation with selected Oenococcus oeni lyophila shortened MLF duration up to 19 days and lead to wines with more fresh and fruity characters, especially when implantation was 100%. We demonstrated modifications in the concentration of volatile and nitrogenous compounds and a good correlation between analytical and sensory attributes was also noted. In addition, the low initial amino acid concentration and the consumption of these compounds by the inoculated yeast strain during alcoholic fermentation resulted in wines with very low biogenic amines levels (under 3.75 mg L^?1) after MLF and 3 month storage period in all cases. The results showed the significance of choose the most suitable starter to elaborate quality wines and suggest the control of amino acid content in must and wine to prevent the formation of biogenic amines.