Small Alterations in Cobinamide Structure Considerably Influence sGC Activation

Specially designed B‐ring‐modified cobalamin derivatives were synthesized and tested as potential activators of soluble guanylyl cyclase (sGC). Herein, we disclose the influence of substituents at the c‐ and d‐positions in hydrophilic and hydrophobic cobyrinic acid derivatives on their capacities to activate sGC. The presence of the amide group at c‐/d‐position in cobyrinic acid derivatives strongly influence the level of sGC activation. Removal of the d‐position altogether has a profound effect for hydrophobic compounds. In contrast, little differences were observed in hydrophilic ones.     

Characterization of Pure and Modified TiO_{2} Layer on Glass and Aluminum Support by Beam Deflection Spectrometry

\(\mathrm {TiO}_{2}\) thin films used as photocatalysts in environmental applications were studied by beam deflection spectroscopy (BDS) and by atomic force microscopy. A novel multiparameter theoretical model was developed in order to explain BDS experimental data. The fundamental parameters of examined films: thermal diffusivity, thermal conductivity, and charge transport properties such as the value of the energy bandgap, carrier lifetime, concentration, and type of dopants, were obtained as results of the modeling of BDS data. With BDS, we observed that the material’s thermal conductivity and thermal diffusivity depend also on the porosity and the surface roughness of films. Consequently, the photocatalytic performance can be estimated by measuring the thermal diffusivity of films. Furthermore, we found that surface roughness is prone to changes when the film is used as photocatalysts in water purification processes. During the purification process, the roughness decreases and the photocatalytical performance drops. Moreover, it was discovered that the thermal, electrical, and morphological properties of photocatalysts films depend on the support to which the \(\mathrm {TiO}_{2}\) layer is deposited. These complex relations demonstrate that knowledge of fundamental physical parameters is required in order to improve the photocatalytic performance of \(\mathrm {TiO}_{2}\) films. In this view, the BDS measurements offer a tool for noncontact and nondestructive evaluation of thermal and electronic parameters of thin film \(\mathrm {TiO}_{2}\) photocatalysts as demonstrated in this work.     

The influence of powder morphology on the effect of rosemary aroma microencapsulation during spray drying

The influence of particle morphology of spray dried powders obtained by using different carriers on the efficiency of microencapsulation of rosemary aroma is shown in the present research. It was found that the type of the carrier influenced the size but not the shape of rosemary aroma capsules and all the capsules were spherical with cracks. The biggest particles, d₅₀ = 55 μm, were obtained with 25% maltodextrin (MD) as a carrier, and the smallest, d₅₀ = 29 μm with 30% gum arabic (GA). The efficiency of encapsulating aroma inside of the capsules depended on the particles size and apparent density. An increase in the quantity of microencapsulated aroma from 10% for 25% MD to about 60% for 30% GA as the carrier was seen, which co‐related with a decrease in the average diameter of the powder particles. Similarly, an increase in the efficiency of aroma retention was followed by an increase of apparent density of powders from 796 (25% MD) to 1156 kg m^?3 (30% GA).     

Application of monodispersive anion exchangers in sorption and separation of y3+ from Nd3+ and Sm3+ complexes with dcta

Rare earth complexes with trans-1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid (DCTA) of the Ln(dcta)- ype exhibited an unusual sequence of affinity on the polystyrene anion exchangers: pm3 >Nd3 >Sm3 >pr3 >Ce3 >Eu3 >Gd3 >La3 >Sc3 >Tb3 >Dy3 >Ho3 >y3 >Er3 >Tm3 >yb3 >Lu3 [1]. Taking into account the position of Y3 , Sm3 , and Nd3 in this affinity series, for the monodispersive polystyrene anion exchangers, Lewafit MonoPlus M 500, Lewatit MonoPlus M 600, Lewatit MonoPlus MP 500, Lewatit MonoPlus MP 64,and for the heterodispersive anion exchanger, Lewatit MP 62, the weight (Dg,) and bed (Dv) distribution coefficients of these complexes and working ion exchange capacities (Cw) were determined. Based on these values, purifications of Y3 from Nd3 and y3 from Sm3 in the macro-micro component system on these anion exchangers were studied. The application potential of this method was highlighted for the separation of yz3 in the presence of Nd3 and Sm3 . With 1 L of monodispersive and strongly basic polystyrene gel anion exchanger Lewatit MonoPlus M 500 in the acetate form, it is possible to obtain approximately 79 g Y2O3 purified from Nd2O3 and 70 g Y2O3 purified from Sm2O3 in the same process condition.     

Flammability and thermal properties of rigid polyurethane foams with additionally introduced cyclic structures

Flammability, smoke evolution, thermal, and thermomechanical properties of low-density rigid polyurethane foams obtained from different aromatic polyols were investigated. The foams were prepared according to a standard formulation ensuring the same foam phosphorus content. Cellular polyurethanes with the best fire resistance were obtained from polyols containing disubstituted naphthalene and biphenyl rings. A linear equation was proposed to describe the influence of various structural units of the polyurethane (the content of cyclic structures C_c, nitrogen content C_N, and crosslinking equivalent M_c) upon its flammability, expressed in terms of its oxygen index (OI) Thermal stability of crosslinked polyurethanes was not found to influence significantly their thermomechanical properties, while crosslink density and the type and quantity of cyclic structures additionally introduced did have a pronounced effect upon these properties.     

Studies on the usefulness of Cucurbita maxima for the production of ready-to-eat dried vegetable snacks with a high carotenoid content

Recent research indicates a beneficial influence of a diet rich in β-carotene on human health. For that reason, experiments were undertaken to process winter squash with a high carotenoid content into ready-to-eat dried snacks. Sensory quality and dietary value of chips and crispy cubes made from different cultivars were investigated.The suitability of winter squash for drying purposes depended mainly on the dry matter content in the raw material. Although all the investigated cultivars can be used for producing chips, obtaining high quality porous cubes requires at least 15% of dry matter. ‘Justynka F1’ emerged as the most suitable cultivar for processing; both chips and cubes produced from its fruits were characterized by a high sensory quality and contained significant amounts of beta-carotene (225- 253 μg g-1). Also, the cultivar ‘Amazonka’ could be considered for the production of chips as it allowed us to obtain a product with a high beta-carotene content (200 μg g-1) and good sensory properties. The dried ready-to-eat crispy vegetable snacks made from the new cultivars of winter squash could be exploited as a novel attractive product with the attractive taste and colour to serve as a valuable source of carotenoids in human diet.     

The antioxidant properties of alcoholic extracts from Sambucus nigra L. (antioxidant properties of extracts)

The antioxidant properties of alcoholic extracts from the leaves, berries and flowers of Sambucus nigra L. are estimated by means of DPPH and β-carotene/linoleic acid methods, and considered in relation to the extraction temperature (in the range 20-200 °C) and to the level of flavonoids most representative for this plant. The extracts of S. nigra act as antioxidants neutralizing the activities of free radicals and inhibiting the co-oxidation reactions of linoleic acid and β-carotene. There is no direct correlation between the level of flavonoids in the extracts and their antioxidant activity. The data presented show that the extraction temperature strongly influences the antioxidant properties of the extracts, especially in the case of leaves.     

Kinetics of lactose hydrolysis and galactooligosaccharides formation in beverages based on goat’s milk and its permeate

Food Science and Biotechnology - The aim of this work was the analysis of galactooligosaccharides (GOS) formation in a model mixture of goat’s milk and its permeate from microfiltration and...     

Ligand-Tuning of the Stability of Pd(II) Conjugates with Cyanocobalamin

Besides the well-known functions performed by vitamin B₁₂ (CblCN) in biochemical processes of the human body, an increasing interest has been raised by the possibility of its use as a transmembrane drug carrier, capable, among others, of enhancing the accumulation of inorganic cytostatics in cancer cells. The present study was aimed at determining the possibility of the formation of CblCN conjugates with Pd(II) complexes. A key aspect was their stability, which we attempted to tune by appropriate choice of ligands. Syntheses, spectroscopic analysis of postreaction systems and kinetic investigations of conjugate formation reactions, have been complemented by DFT modelling. The obtained results showed that ligand charge, geometry and electron affinity may have a significant impact on carrier binding and release leading to the activation of the Pd(II) complex. This provides a rationale to expect that with appropriate composition of the coordination sphere, it will be possible to extend the spectrum of less toxic inorganic chemotherapeutics.