Exploring seed and meal composition and protein solubility in soybean genotypes from different domestication periods

Traditionally, commercial soybean breeding has focused on increasing seed yield by crossing elite cultivars and limiting the genetic diversity within commercial germplasm. Wild and ancestral soybean genotypes have higher seed protein concentrations than commercial ones. Different seed protein concentrations and compositions result in diverse functional properties of soybean meal, in particular solubility is important for beverages and protein isolates production. The objectives of our study were (i) to characterize seed protein concentration and composition in genotypes from different soybean domestication periods (types) and (ii) to evaluate the protein concentration and solubility profiles of the defatted meals obtained from these genotypes. Variation within seed and meal protein concentration, composition, and solubility was evident along the domestication process. Wild relative (G. soja) and Elite genotypes had the maximum and minimum seed protein concentrations, respectively (42.9 and 36.3 g 100 g⁻¹). Soybean meal protein concentrations were 55.1, 47.7, 48.4 and 44.1 g 100 g⁻¹ for Wild relative (G. soja), Asian landraces, North American (Nam) ancestors and Elite, respectively. Ample genotypic variation was observed for β-conglycinin components, such as for β, α, and α′ subunits and for total glycinin and its components. Asian landraces had the highest protein solubility. Wild and ancestral germplasm are a reservoir of useful traits to improve soybean seed quality. This study opens the gates to the introduction of ancestral germplasm to breeding programs focused on protein quality and functionality.     

Computational modelling of explosions caused by failed Li-ion batteries

The implementation rate of renewable energy sources such as lithium-ion batteries has grown over the last decade. Consequently, the number of explosion occurrences associated with these batteries has also increased. Such events are due to a process called thermal runaway (TR). The flamelet combustion approach has been widely used to model premixed combustion. However, its applicability for modelling accidental explosions from lithium-ion batteries remains limited. Moreover, the effects and contributions from stress, strain, and wrinkling on the flame front in gas mixtures from Li-ion batteries are not fully understood. As far as computational modelling is concerned, the same effects require further investigation. The current research investigates the performance of the flamelet approach for modelling premixed combustion scenarios caused by the gases ejected by a fully charged lithium-ion-phosphate (LFP) battery. A new laminar burning velocity correlation is proposed based on experimental data to calculate overpressure, flame position, and flame velocity in a semi-confined geometry. Promising results are presented resorted by good agreement with experimental data.     

The Veterinary Anti-Parasitic Selamectin Is a Novel Inhibitor of the Mycobacterium tuberculosis DprE1 Enzyme

Avermectins are macrocyclic lactones with anthelmintic activity. Recently, they were found to be effective against Mycobacterium tuberculosis, which accounts for one third of the worldwide deaths from antimicrobial resistance. However, their anti-mycobacterial mode of action remains to be elucidated. The activity of selamectin was determined against a panel of M. tuberculosis mutants. Two strains carrying mutations in DprE1, the decaprenylphosphoryl-β-D-ribose oxidase involved in the synthesis of mycobacterial arabinogalactan, were more susceptible to selamectin. Biochemical assays against the Mycobacterium smegmatis DprE1 protein confirmed this finding, and docking studies predicted a binding site in a loop that included Leu275. Sequence alignment revealed variants in this position among mycobacterial species, with the size and hydrophobicity of the residue correlating with their MIC values; M. smegmatis DprE1 variants carrying these point mutations validated the docking predictions. However, the correlation was not confirmed when M. smegmatis mutant strains were constructed and MIC phenotypic assays performed. Likewise, metabolic labeling of selamectin-treated M. smegmatis and M. tuberculosis cells with ¹⁴C-labeled acetate did not reveal the expected lipid profile associated with DprE1 inhibition. Together, our results confirm the in vitro interactions of selamectin and DprE1 but suggest that selamectin could be a multi-target anti-mycobacterial compound.     

Recent advances in assessment of marine lipid oxidation by using fluorescence

Lipid changes during food processing are important because of their impact on the final product quality. Lipid damage detection is limited because of the ability of lipid oxidation products (i.e., hydroperoxides and carbonyl compounds) to produce interaction compounds by reacting with nucleophilic food constituents. Fluorescence quantification at a single excitation/emission maximum of these interaction compounds has been employed in a qualitative way as a complementary tool for food quality assessment. The present work reviews recent research where simultaneous detection at different excitation/emission maxima was employed to assess lipid oxidation and quality changes during fish processing. A fluorescence shift towards a higher wavelength maxima was detected as a result of lipid damage; the shift was calculated as the ratio (δF) between two of the maxima tested (393/463 nm and 327/415 nm) and was investigated along different fish processes (freezing and frozen storage, refrigerated storage, cooking, and canning) and in complementary model systems where the influence of different factors (time and temperature of processing, amine and aldehyde composition and content, formaldehyde presence, and pH value of the medium) was checked. Determination of the δF value provided better results for quality change assessment in fish products than most of the lipid quality indices, in addition to being rapid and sensitive.     

Grain boundary segregation and interdiffusion effects in nickel-copper alloys: an effective means to improve the thermal stability of nanocrystalline nickel

Nanocrystalline (nc) Ni films show pronounced grain growth and suffer from concomitant deterioration of their mechanical and magnetic properties after annealing at relatively low temperatures (T(ANN) ≥ 475 K). This constitutes a drawback for their applicability as coatings or in components of miniaturized devices. This work reveals that the thermal stability of nc Ni is significantly improved by controllably alloying Ni with Cu, by means of electrodeposition, to form a Ni(1-x)Cu(x) solid solution. To tune the composition of such nc alloys, Ni(1-x)Cu(x) films are deposited galvanostatically using an electrolytic bath containing Ni and Cu sulfate salts as electroactive species, saccharine as grain-refining agent, and applying current densities ranging from -10 to -40 mA cm(-2). The enhanced thermal stability is ascribed to segregation of a Cu-rich phase at the Ni(1-x)Cu(x) grain boundaries, which acts as a shielding layer against grain growth. As a result, high values of hardness (in excess of 6 GPa) remain in nc Ni(1-x)Cu(x) for x ≥ 0.3, even after annealing at T(ANN) ≥ 575 K. From a magnetic point of view, Ni(1-x)Cu(x) films possess lower coercivity values than pure nc Ni films, both in the as-prepared and annealed states, thus offering potential advantages for certain soft magnetic applications.     

Optical and photoelectrical studies of gold nanoparticle-decorated C60 films

Optical and photoelectrical studies were performed on octane-1,8-dithiol cross-linked fullerene films, with supported gold nanoparticles (C₆₀-DT-Au). According to high-resolution transmission electron microscopy observations, the average size of obtained gold nanoparticles was about 5 nm, and the shape was spherical. The comparative investigation of optical properties of pristine and cross-linked with octane-1,8-dithiol C₆₀ films, decorated with gold nanoparticles, found the difference in the extinction coefficient spectra, which was observed also in the photocurrent spectra of barrier heterostructure Au/C₆₀/Si. The analysis of dark current-voltage characteristics for Au/C₆₀/Si heterostructures showed that the model for them includes the barrier at the C₆₀/Si interface and internal barriers in the C₆₀ layer, caused by the trapping centers. The hopping mechanism of the current transport in the C₆₀ layer was supplemented with the Poole-Frenkel emission process on these centers, with the barrier height greater for the fullerene C₆₀ film cross-linked with octane-1,8-dithiol.     

Enhanced Photoacoustic Beam Profiling of Pulsed Lasers

An improved version of a photoacoustic beam profiler of pulsed lasers is presented. The new model resorts to high-bandwidth condenser microphones to register higher-order, excited acoustic modes, thus enabling more accurate profiling. In addition, Xe was used as a buffer gas since its high atomic weight further reduces the eigenfrequencies. Furthermore, a new gas-handling system makes up for some deficiencies found in the first model. The system was calibrated using the Airy pattern generated with a pinhole illuminated by a frequency-doubled Nd:YAG laser that excited $\text{ NO }_{2}$ traces. Once calibrated, the beam profile of a TEA $\text{ CO }_{2}$ laser was obtained, using ethylene as the absorbing species. This profiler returns more accurate profiles than thermal paper.     

Preconcentration, separation, and indirect detection of nonfluorescent analytes using fluorescent mobility markers

We present a method to achieve separation and indirect detection of nonfluorescent species using fluorescent mobility markers. This technique leverages isotachophoresis (ITP) for both preconcentration and separation. We employ a leading electrolyte (LE), trailing electrolyte (TE), and a set of fluorescent markers of mobilities designed to bound those of nonfluorescent analytes of interest. Fluorescent markers and nonfluorescent analytes are initially mixed homogenously and ITP is initiated. The dynamics of isotachophoresis cause the analyte and fluorescent marker mixture to segregate into respective zones between the LE and TE in the order of reducing mobility. Unlabeled analytes are detected as gaps (regions with local minimums in intensity) in the fluorescent signals of mobility markers. We have successfully demonstrated preconcentration, separation, and detection of unlabeled amino acids serine, glycine, and phenylalanine; and of acetic acid, aspartic acid, and 3-phenylpropionic acid. We show detection of 12 microM concentration of analytes with signal-to-noise ratio of 4.0 and with a high degree of repeatability. We discuss methods for encoding mobility marker identity using marker fluorescence intensity level and alternating fluorescence emission wavelengths. We present example experimental results of fluorescence intensity level encoding.     

Sulfamethoxazole abatement by means of ozonation

Sulfamethoxazole (SMX) is a bacteriostatic antibiotic largely used for diverse types of illness. Its widely use in humans and even in animals releases unmetabolized and active metabolites that have a strong potential in terms of effect in organisms. In this work, 200 mg L⁻¹ solution of sulfamethoxazole was treated by ozonation at different pH. Results showed that ozonation was proved to be an efficient method to degrade sulfamethoxazole. After 15 min of ozonation (corresponding dose = 0.4 g of ozone L⁻¹), the complete antibiotic abatement was almost achieved with just 10% of mineralization. The biodegradability and toxicity of the ozonation intermediates were also studied. A biodegradability enhancement (increment of BOD₅/COD ratio) from 0 to 0.28 was observed after 60 min of ozonation. The acute toxicity of the intermediates was followed by the Microtox^® test and the toxicity profile showed a slight acute toxicity increment in the first stage of ozonation. The pH variation had an important role in the TOC and COD removal, promoting their growth with the increment of alkalinity. The second order kinetic constants for the ozonation of the SMX in an order of magnitude of 10⁵ L mol⁻¹ s⁻¹ were also determined for pH 5 and 7.