Peculiarities of U(VI) sorption on composites containing hydrated titanium dioxide and potassium-cobalt hexacyanoferrate(II)

As opposed to polymer sorbents, inorganic materials are stable against ionizing radiation. This gives a possibility to use them for the removal of radionuclides from water. As a rule, highly selective inorganic sorbents are obtained in a form of finely dispersive powder. This makes it difficult to use them in practice. Here the composites based on hydrated titanium dioxide containing K2Co[Fe(CN)6] have been developed. The modifier was inserted into partially (hydrogel) and fully (xerogel) formed oxide matrices. Modifying of hydrogel followed its transformation to xerogel provides the formation of potassium-cobalt hexacyanoferrate(II) nanoparticles (up to 10 nm), which are not washed out in aqueous media due to encapsulation in hydrated oxide. A number of the methods for sample characterization were used in this work: transmission electronic microscopy for vizualization of embedded nanoparticles, optical microscopy to measure granule size, FT-IR spectroscopy, X-ray fluorescence spectroscopy for chemical analysis of the samples, potentiometric titration to estimate ion exchange properties, and spectrophotometric analysis of the solution to determine U(VI) concentration. The features of U(VI) sorption from nitrate and sulfate solutions are considered: the effect of the sorbent dosage and solution composition was in a focus of attention. The influence of the modifier is the most pronounced at pH ³ 4, when U(VI) is in a form of one-charged cations (UO2OH+): the removal degree of U(VI) is close to 100 %. This positive effect of the selective constituent is expressed in a presence of an excess of NO3–, SO42– and Na+ ions. The model of chemical reaction of pseudo second order has been applied to sorption. Both pristine sorbent and composite are most completely regenerated with a 0.1 M KOH solution - the regeneration degree is 92 and 96 % respectively. In this case, the half-exchange time is minimal and equal to » 23 min (initial hydrated titanium dioxide) and 47 min (composite). Desorption obeys the model of particle diffusion: the diffusion coefficients for ions being exchanged are (1.7–7.6)´10–13 m2s–1.

Phytochemical analysis and investigation of Antimicrobial and Antioxidant potential of the Leaf Extracts of Putranjiva ruxburghi

Objectives: Herbs are in use as medicine worldwide from the time immemorial. Many drugs derived from plant, animal or minerals are in use as medicine till date. This is a study on leaf extract of Putranjiva roxburghii Wall. (Euphorbiaceae) involving pharmacognosy, phytochemistry, activity against microbes and oxidation to substantiate its use. The leaf extracts were collected by successive soxhlation using solvents like petroleum ether, chloroform, benzene, acetone & ethanol. Chemicals present in the crude leaf extracts and isolated constituents were analyzed for both quality and quantity followed by TLC, UV–Visible Spectrophotometric analysis, HPTLC, Phytochemical tests and TLC examination confirmed to contain flavonoids in acetone, chloroform, aqueous and ethanol extract. The activity of Petroleum-ether, chloroform, acetone, alcoholic and aqueous extracts against the microbes was assessed by cup plate method. Okada & Okada method was followed to evaluate the DPPH free radical for aging property. The reducing, total antioxidant and peroxide radical for aging action of the extracts were assessed. The study confirmed significant antimicrobial and antioxidant property of the Putranjiva roxburghii Wall leaves may be for the presence of constituents like flavonoids, saponins, Phytosterols, favoring its traditional usage as medicine.

Optimal Design Approach Applied to Headspace GC for the Monitoring of Diacetyl Concentration, Spectrophotometric Assessment of Phenolic Compounds and Antioxidant Potential in Different Fermentation Processes of Barley

The present study aimed to validate a control method on the gas chromatography system (GC) based on the experimental design strategy, to examine the changes and correlation between the fermentation process and the quality of alcoholic and non-alcoholic beer product, especially the formation of diacetyl. On the other hand, spectrophotometric methods were applied to the determination of polyphenols content and the potential antioxidant activity of beer during different fermentation processes. with this aim, three modes of barley fermentation were used, specifically classical fermentation, stopped fermentation and thermal process. The results showed that the different fermentation modes had a major impact on diacetyl production. The highest concentration was obtained using stopped fermentation 0.36 mg/L, the lowest concentration value 0.07 mg/L was detected using the thermal process. Monitoring the increase of oxygen concentration between fermentation, filtration, and filling of the final product (32, 107, 130 ppm, respectively) has a significant impact on the concentration of diacetyl. The obtained results of spectrophotometric analysis showed that the total antioxidant activity changed during beer fermentation process and demonstrate that the extend of the antioxidant activity was very much dependent on the total polyphenolic content with a higher value in Hopped wort (13.41%, 65 mg GAE 100 mL−1, 28 mg CE 100 mL−1) for antioxidant potential, total phenolic content, and total flavonoids content, respectively, whereas the lowest values was detected in Non-alcoholic beer using thermal process (7.24%, 35 mg GAE 100 mL−1, 10 mg CE 100 mL−1) for antioxidant potential, total phenolic contents, and total flavonoids contents, respectively. Based on the results achieved, we reveal the impact of the fermentation process on the nutritional value of the final product.

Multiband Imaging of the HD 36546 Debris Disk: A Refined View from SCExAO/CHARIS*

We present the first multiwavelength (near-infrared; 1.1–2.4 μm) imaging of HD 36546's debris disk, using the Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) system coupled with the Coronagraphic High Angular Resolution Imaging Spectrograph (CHARIS). As a 3–10 Myr old star, HD 36546 presents a rare opportunity to study a debris disk at very early stages. SCExAO/CHARIS imagery resolves the disk over angular separations of ρ ∼ 0.″25–1.″0 (projected separations of rproj ∼ 25–101 au) and enables the first spectrophotometric analysis of the disk. The disk’s brightness appears symmetric between its eastern and western extents, and it exhibits slightly blue near-infrared colors on average (e.g., J−K = −0.4 ± 0.1)—suggesting copious submicron-sized or highly porous grains. Through detailed modeling adopting a Hong scattering phase function (SPF), instead of the more common Henyey–Greenstein function, and using the differential evolution optimization algorithm, we provide an updated schematic of HD 36546's disk. The disk has a shallow radial dust density profile (α in ≈ 1.0 and α out ≈ −1.5), a fiducial radius of r 0 ≈ 82.7 au, an inclination of i ≈ 79.°1, and a position angle of PA ≈ 80.°1. Through spine tracing, we find a spine that is consistent with our modeling, but also with a “swept-back wing” geometry. Finally, we provide constraints on companions, including limiting a companion responsible for a marginal Hipparcos–Gaia acceleration to a projected separation of ≲0.″2 and to a minimum mass of ≲11 M Jup.

Trace Mineral, Qualitative Phytochemical Composition and Antidiabetic Effect of Ethanol Extract of Citrullus lanatus Seeds on Diabetic Rats

The trace mineral concentration, phytochemical composition and antidiabetic effect of the ethanol extract of C. lanatus seeds were carried out using standard methods. The preclinical experimental model was 120 mgkg-1 b.w. (via intraperitoneal) Alloxan induced diabetic rat model, with ethanol extract of C. lanatus seeds administered orally at 500mgkg-1 b.w. Qualitative phytochemical screening showed presence of alkaloids, flavonoids, saponins, cardiac glycosides, steroids/triterpenoids, tannins, carbohydrates and oils. Atomic Absorption Spectrophotometric analysis revealed that iron had the highest value (8.31mgkg-1), followed by zinc (5.78 mgkg-1), then manganese (4.28 mgkg-1). Selenium concentration was appreciable (0.85 mgkg-1). Ethanol extract of C. lanatus seeds significantly (p < 0.05), dose and time dependently reduced blood glucose level, increased body weights of rats and had positive effect on organ weights and organ volume. The results in this study showed that Citrullus lanatus seeds are rich in zinc, selenium, manganese, iron, alkaloids, flavonoids, saponins, cardiac glycosides, steroids/triterpenoids, and tannins. They may therefore serve as good sources of these trace mineral nutrients and bio actives for nutritional and medicinal purposes relating to diabetes management.

Phytochemical analysis and antimicrobial and antioxidant activities of Hen-riettea succosa (Aubl.) DC. leaves

Henriettea succosa is a tree species consumed in abundance by birds, however, there is no report on its phytochemical profile and biological activity. This study performed the phytochemical screening and the antimicrobial and antioxidant potential of H. succosa leaves. The hexane (Hex), ethyl acetate (AcOEt) and methanol (MeOH) extracts of the leaves were evaluated for chemical composition by Thin Layer Chromatography and spectrophotometric analysis; the antimicrobial activity was determined by the Minimum Inhibitory Concentration (MIC) and Minimum Microbicide Concentration (MMC); antioxidant activity was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging, determination of the reducing power and the phosphomolybdenum complex reduction assay. The photoprotor action of the extracts was also evaluated. The results showed a higher content of phenolic compounds (444.08 ± 0.020 mg EAG/g) and tannins (414.37 ± 0.16 mg EAG/g) in the MeOH extract, which was effective against Staphylococcus aureus and Serratia marcescens, with MIC of 1 mg/ ml and CMM of 2 mg/ml. The MIC and MMC of AcOEt for Micrococcus luteus was 1 mg/mL, this was also considered the minimum concentration necessary for the Hex extract to act on the S. aureus strain. The MeOH extract showed greater antioxidant activity by the DPPH (79.09%) and reducing power (327.2 ± 0.00 mg EAA/g) methods, while the AcOEt extract showed greater activity by the phosphomolybdenum method (40.5%). However, none of the extracts showed a photoprotective effect against UV radiation. In summary, this study revealed that the leaves of H. succosa have secondary metabolites with bactericidal potential, in addition to antioxidant action.

Susceptibility of Dental Caries Microcosm Biofilms to Photodynamic Therapy Mediated by Fotoenticine

Photodynamic therapy (PDT) mediated by Fotoenticine® (FTC), a new photosensitizer derived from chlorin e-6, has shown in vitro inhibitory activity against the cariogenic bacterium Streptococcus mutans. However, its antimicrobial effects must be investigated on biofilm models that represent the microbial complexity of caries. Thus, we evaluated the efficacy of FTC-mediated PDT on microcosm biofilms of dental caries. Decayed dentin samples were collected from different patients to form in vitro biofilms. Biofilms were treated with FTC associated with LED irradiation and analyzed by counting the colony forming units (log10 CFU) in selective and non-selective culture media. Furthermore, the biofilm structure and acid production by microorganisms were analyzed using microscopic and spectrophotometric analysis, respectively. The biofilms from different patients showed variations in microbial composition, being formed by streptococci, lactobacilli and yeasts. Altogether, PDT decreased up to 3.7 log10 CFU of total microorganisms, 2.8 log10 CFU of streptococci, 3.2 log10 CFU of lactobacilli and 3.2 log10 CFU of yeasts, and reached eradication of mutans streptococci. PDT was also capable of disaggregating the biofilms and reducing acid concentration in 1.1 to 1.9 mmol lactate/L. It was concluded that FTC was effective in PDT against the heterogeneous biofilms of dental caries.