Gradient silver nanoparticle layers in absorbing coatings--experimental study

Metal island films show a characteristic absorption peak related to the surface plasmon resonance of free electrons. This kind of film can be used in absorbing coatings, together with dielectric layers. Such absorbing multilayer coatings, with and without the gradient of the silver mass thickness in metal island films throughout the coating, have been deposited by electron beam evaporation. It is shown experimentally that coatings with a gradient in the mass thickness of silver nanoparticles have higher absorption than equivalent nongradient coatings with the same total mass thickness of silver nanoparticles.     

Volatile compounds and proteolysis in traditional Beaten (Bieno sirenje) ewe's milk cheese

Beaten ewe's milk cheese is a traditional autochthonous type of cheese manufactured in Macedonia with a relatively high nutritional value and sensory characteristics. The objective of this study was to characterise the gross composition, proteolysis and volatile profiles of the cheese that is supplied from different retails. The ranges for gross composition were from 31.53% to 42.83% (w/w) for moisture, 41.99% to 50.98% (w/w) for fat‐in‐dry matter, 2.03% to 8.25% (w/w) for salt content and 20.74% to 33.35% (w/w) for protein. Proteolysis results showed various levels of soluble nitrogen ranged from 3.15 to 33.50 for water‐soluble nitrogen (WSN) and from 1.11% to 6.79% for nitrogen soluble in 12% trichloroacetic acid (TCA‐SN). The ranges for total free amino acids were from 1.65 to 8.06 mg Leu/g. Lower proteolysis was observed in the cheese samples due to high salt contents. In total, 65 volatile compounds were identified in Beaten cheese. As a conclusion, the variation of the peptide profile, electrophoresis and volatile contents of Beaten cheeses are due to the lack of standardised manufacture protocols.     

Powdered barley sprouts: composition,functionality and polyphenol digestibility

This study was performed to evaluate the phytochemical composition, in vitro antioxidant capacity, antihyperglycaemic and anti‐inflammatory activities, and simulated gastrointestinal digestion of 7‐day‐old freeze‐dried barley sprouts (BS), one hybrid and one nonhybrid variety: ‘NS565’ (BSNS) and ‘Golozrni’ (BSG), respectively. BSNS expressed significantly higher (P ≤ 0.05) content of total phenols, chlorophyll and carotenoids. Phenolic compounds were the most dominant bioactives in both BSNS and BSG (713.25 and 479.02 mg GAE 100 g^?1 DW, respectively). BSNS possessed significantly higher (P ≤ 0.05) antioxidant capacity, evaluated by DPPH and ABTS assays, and reducing power ( = 0.54 mg mL^?1; IC₅₀^ABTS = 0.79 mg mL^?1; RP_0.5 = 9.35 mg mL^?1). Antihyperglycaemic and anti‐inflammatory activities of BSNS ( = 1.43 mg mL^?1;  = 1.86 mg mL^?1) were also significantly higher (P ≤ 0.05) than BSG ( = 1.97 mg mL^?1;  = 4.40 mg mL^?1). In vitro simulation of gastrointestinal digestion showed higher release of phenolic compounds in intestinal fluid than in gastric fluid.     

Optimization of the GC method for routine analysis of the fatty acid profile in several food samples

The fatty acids profile of food samples was determined by gas chromatography (GC). The fat was extracted from different food samples using Soxhlet technique. Extracted triglycerides were converted to corresponding methyl esters using methanolic solution of potassium hydroxide (trans-esterification). GC method for the analysis of obtained methyl esters was optimized on two different cyanopropyl capillary columns. Good resolution of all fatty acids commonly found in foodstuffs was achieved. After optimization, the method was validated and the results for linearity, precision, limit of quantitation (LOQ), limit of detection (LOD), robustness and stability were presented. The method has been applied to the quantitative determination of the fatty acid content in different food samples: edible oil, dairy products rich with omega-3 fatty acids, different food supplements, baby food, etc.     

N-甲基甘氨酸及类乙二胺二乙酸型配体钴(Ⅲ)配合物的合成与表征

合成了N-甲基甘氨酸及相应四齿配体[乙二胺二乙酸(edda)、乙二胺二丙酸(eddp)、1,3-丙二胺二乙酸(pdda)]钴(Ⅲ)配合物的几种经式几何异构体,其中edda和eddp钴(Ⅲ)配合物的合成是通过相应的N-甲基甘氨酸与edda碳酸合钴(Ⅲ)酸钠及反对称-顺式-pdda碳酸合钴(Ⅲ)酸钠二水合物来制备的.而pdda-Co(Ⅲ)配合物采用一种新方法直接合成(CoCl2*H2O在有PbO2存在下直接与pdda反应).诸配合物通过层析色谱柱分离,并用元素分析、电子光谱、红外和1H核磁共振所表征.     

Maternal Dexamethasone Exposure Induces Sex-Specific Changes in Histomorphology and Redox Homeostasis of Rat Placenta

As the mediator between the mother and fetus, the placenta allows the most appropriate environment and optimal fetal growth. The placenta of one sex sometimes has a greater ability over the other to respond to and protect against possible maternal insults. Here, we characterized sex differences in the placenta’s morphological features and antioxidant status following dexamethasone (Dx) exposure. Pregnant rats were exposed to Dx or saline. The placenta was histologically and stereologically analyzed. The activity of the antioxidant enzymes, lipid peroxides (TBARS), superoxide anion and nitric oxide (NO) was measured. The decrease in placental zone volumes was more pronounced (p < 0.05) in female placentas. The volume density of PCNA-immunopositive nuclei was reduced (p < 0.05) in both sexes. The reduced (p < 0.05) antioxidant enzyme activities, enhanced TBARS and NO concentration indicate that Dx exposure triggered oxidative stress in the placenta of both fetal sexes, albeit stronger in the placenta of female fetuses. In conclusion, maternal Dx treatment reduced the size and volume of placental zones, altered placental histomorphology, decreased cell proliferation and triggered oxidative stress; however, the placentas of female fetuses exerted more significant responses to the treatment effects. The reduced placental size most probably reduced the transport of nutrients and oxygen, thus resulting in the reduced weight of fetuses, similar in both sexes. The lesser ability of the male placenta to detect and react to maternal exposure to environmental challenges may lead to long-standing health effects.     

Synthesis,Antiproliferative Evaluation and QSAR Analysis of Novel Halogen- and Amidino-Substituted Benzothiazoles and Benzimidazoles

Syntheses of 6-halogen-substituted benzothiazoles were performed by condensation of 4-hydroxybenzaldehydes and 2-aminotiophenoles and subsequent O-alkylation with appropriate halides, whereas 6-amidino-substituted benzothiazoles were synthesized by condensation of 5-amidino-2-aminothiophenoles and corresponding benzaldehydes. While most of the compounds from non-substituted and halogen-substituted benzothiazole series showed marginal antiproliferative activity on tested tumor cell lines, amidino benzazoles exhibited stronger inhibitory activity. Generally, imidazolyl benzothiazoles showed pronounced and nonselective activity, with the exception of 36c which had a strong inhibitory effect on HuT78 cells (IC₅₀ = 1.6 µM) without adverse cytotoxicity on normal BJ cells (IC₅₀ >100 µM). Compared to benzothiazoles, benzimidazole structural analogs 45a–45c and 46c containing the 1,2,3-triazole ring exhibited pronounced and selective antiproliferative activity against HuT78 cells with IC₅₀ < 10 µM. Moreover, compounds 45c and 46c containing the methoxy group at the phenoxy unit were not toxic to normal BJ cells. Of all the tested compounds, benzimidazole 45a with the unsubstituted phenoxy central core showed the most pronounced cell growth inhibition on THP1 cells in the nanomolar range (IC₅₀ = 0.8 µM; SI = 70). QSAR models of antiproliferative activity for benzazoles on T-cell lymphoma (HuT78) and non-tumor MDCK-1 cells elucidated the effects of the substituents at position 6 of benzazoles, demonstrating their dependence on the topological and spatial distribution of atomic mass, polarizability, and van der Waals volumes. A notable cell cycle perturbation with higher accumulation of cells in the G₂/M phase, and a significant cell increase in subG0/G1 phase were found in HuT78 cells treated with 36c, 42c, 45a–45c and 46c. Apoptotic morphological changes, an externalization of phosphatidylserine, and changes in the mitochondrial membrane potential of treated cells were observed as well.     

A Conformationally Stable Acyclic β-Hairpin Scaffold Tolerating the Incorporation of Poorly β-Sheet-Prone Amino Acids

The β-hairpin is a structural element of native proteins, but it is also a useful artificial scaffold for finding lead compounds to convert into peptidomimetics or non-peptide structures for drug discovery. Since linear peptides are synthetically more easily accessible than cyclic ones, but are structurally less well-defined, we propose XWXWXpPXK(/R)X(R) as an acyclic but still rigid β-hairpin scaffold that is robust enough to accommodate different types of side chains, regardless of the secondary-structure propensity of the X residues. The high conformational stability of the scaffold results from tight contacts between cross-strand cationic and aromatic side chains, combined with the strong tendency of the d -Pro-l -Pro dipeptide to induce a type II′ β-turn. To demonstrate the robustness of the scaffold, we elucidated the NMR structures and performed molecular dynamics (MD) simulations of a series of peptides displaying mainly non-β-branched, poorly β-sheet-prone residues at the X positions. Both the NMR and MD data confirm that our acyclic β-hairpin scaffold is highly versatile as regards the amino-acid composition of the β-sheet face opposite to the cationic−aromatic one.