Encapsulation of titanium (IV) silsesquioxane into the NH4USY zeolite: Preparation, characterization and application

This work describes the encapsulation of titanium (IV) silsesquioxane into the supercavities of NH₄USY ultra stabilized zeolite, after chemical treatment. The modified zeolite was characterized by Fourier transform infrared spectra, Nuclear magnetic resonance, scanning electronic microscopy, X-ray diffraction and thermogravity. This encapsulated titanium (IV) silsesquioxane can adsorb Azure A chloride after treatment with H₃PO₄, without modifier leaching problems. In an electrochemical study, the cyclic voltammograms of the graphite paste modified electrode, shows two redox couples with formal potential (E⁰′) −0.1 V and 0.21 V to I and II redox couples respectively (v=700 mV s−1; Britton Robinson buffer (B-R) solution, pH 3) versus SCE ascribed to a monomer and dimmer of azure. This paper shows the use of ultra stabilized zeolite in the electrochemical field as host for molecules with nanometric dimensions.     

Fatty acid composition of three freshwater fishes under different storage and cooking processes

Fatty acid composition of common carp (Cyprinus carpio), Nile tilapia (Oreochromis niloticus) and tambacu, a hybrid of tambaqui (Colossoma macropomum) and pacu (Piaractus mesopotamicus), was evaluated by gas chromatography. Raw, roasted and steamed fishes with and without skin were analyzed fresh and after 15, 30 and 45 storage days at −20 °C. Total lipid content was 9.3 g/100 g in carp, 0.79 g/100 g in tilapia and 1.3 g/100 g in tambacu with skin, with reductions of about 63%, 39% and 71% in the fishes without skin, respectively. The carp showed a high content of monounsaturated fatty acids (about 50%). In tilapia, palmitic and oleic acids were present in larger proportion, 26.55% and 23.86%, respectively. In tambacu, the fatty acid profile was 37% saturated, 34% monounsaturated and 21% polyunsaturated. Fatty acid composition did not present wide variations due to storage time and preparation, indicating that the storage and cooking methods used did not interfere in fatty acid composition.     

Cognitive impairment in a patient with COVID-19 on hemodialysis: Too dangerous to neglect!

Neurological manifestations of coronavirus disease 2019 (COVID-19) often have tragic repercussions. Although many reports of neurological complications of severe acute respiratory syndrome coronavirus 2 infection exist, none of them are of patients on hemodialysis, who have a fivefold greater risk of stroke than the general population. In this report, we emphasize the importance of being vigilant for mild stroke in high risk populations—such as patients on hemodialysis—with COVID-19, since these conditions have overlapping symptoms.     

Efficacy of detergents in removing Salmonella and Shigella spp. from the surface of fresh produce

Fresh produce has been implicated in several foodborne disease outbreaks. Produce surfaces can be primary sites of contamination during production and handling. One approach to reduce contamination is to treat fresh produce with rinsing agents. In this study, different detergent agents were used at 22 and 40 degrees C to determine their efficacy in removing Salmonella and Shigella spp. from the surfaces of strawberries, tomatoes, and green-leaf lettuce. Produce was inoculated at 22 degrees C with a cocktail of nalidixic acid-resistant organisms (6 to 6.5 log CFU/ml). After air drying for 1 h, samples were rinsed with either 0.1% Tween 80, 0.1% sodium lauryl sulfate (SLS), or water (control) at 22 or 40 degrees C. Rinse solutions were spiral plated onto tryptic soy agar supplemented with 50 mg of nalidixic acid per liter. In trials involving strawberries and lettuce, Salmonella and Shigella were removed at levels of 4 and 3 log CFU/ml, respectively, except from Salmonella-inoculated strawberries rinsed with SLS, for which minimal removal rates were 1.5 log CFU/ml at 22 degrees C and < 1 log CFU/ml at 40 degrees C. When whole strawberries were analyzed after rinsing with SLS, few organisms were recovered. This result suggests that SLS may have a lethal or sublethal effect on Salmonella, especially when a 40 degrees C solution is used. Salmonella and Shigella removal rates for tomatoes were 1 and 1.5 log CFU/ml lower, respectively, than those for strawberries or lettuce. Overall, detergents were no more effective in removing organisms from produce than water was. The detergents examined would not constitute effective overall produce rinse treatments.     

Overexpression of G0/G1 Switch Gene 2 in Adipose Tissue of Transgenic Quail Inhibits Lipolysis Associated with Egg Laying

In avians, yolk synthesis is regulated by incorporation of portomicrons from the diet, transport of lipoproteins from the liver, and release of lipids from adipose tissue; however, the extent to which lipolysis in adipose tissue contributes to yolk synthesis and egg production has yet to be elucidated. G0/G1 switch gene 2 (G0S2) is known to bind and inhibit adipose triglyceride lipase (ATGL), the rate-limiting enzyme in lipolysis. The objective of this study was to determine whether overexpression of the G0S2 gene in adipose tissue could successfully inhibit endogenous ATGL activity associated with egg laying. Two independent lines of transgenic quail overexpressing G0S2 had delayed onset of egg production and reduced number of eggs over a six-week period compared to non-transgenic quail. Although no differences in measured parameters were observed at the pre-laying stage (5 weeks of age), G0S2 transgenic quail had significantly larger interclavicular fat pad weights and adipocyte sizes and lower NEFA concentrations in the serum at early (1 week after laying first egg) and active laying (5 weeks after laying first egg) stages. Overexpression of G0S2 inhibited lipolysis during early and active laying, which drastically shifted the balance towards a net accumulation of triacylglycerols and increased adipose tissue mass. Thereby, egg production was negatively affected as less triacylglycerols were catabolized to produce lipids for the yolk.     

Effect of Ester to Amide or N‐Methylamide Substitution on Bacterial Membrane Depolarization and Antibacterial Activity of Novel Cyclic Lipopeptides

Cyclic lipopeptides derived from the fusaricidin/LI‐F family of naturally occurring antibiotics represent particularly attractive candidates for the development of new antibacterial agents. In comparison with natural products, these derivatives may offer better stability under physiologically relevant conditions and lower nonspecific toxicity, while preserving their antibacterial activity. In this study we assessed the ability of cyclic lipodepsipeptide 1 and its analogues—amide 2 , N‐methylamide 3 , and linear peptide 4 —to interact with the cytoplasmic membranes of selected Gram‐positive bacteria. We also investigated their bacteriostatic/bactericidal modes of action and in vivo potency by using a Galleria mellonella model of MRSA infection. Cyclic lipopeptides 1 and 2 depolarize the cytoplasmic membranes of Gram‐positive bacteria in a concentration‐dependent manner. The degree of membrane depolarization was influenced by the structural and physical properties of 1 and 2 , with the more flexible and hydrophobic peptide 1 being most efficient. However, membrane depolarization does not correlate with bacterial cell lethality, suggesting that membrane‐targeting activity is not the main mode of action for this class of antibacterial peptides. Conversely, substitution of the depsipeptide bond in 1 with an N‐methylamide bond in 3 , or its hydrolysis to peptide 4 , lead to a complete loss of antibacterial activity and indicate that the conformation of cyclic lipopeptides plays a role in their antibacterial activities. Cyclic lipopeptides 1 and 2 are also capable of improving the survival of G. mellonella larvae infected with MRSA at varying efficiencies, reflecting their in vitro activities. Gaining more insight into the structure–activity relationship and mode of action of these cyclic lipopeptides may enable the development of new antibiotics of this class with improved antibacterial activity.     

An Investigation into Rigidity–Activity Relationships in BisQAC Amphiphilic Antiseptics

Twenty-one mono- and biscationic quaternary ammonium amphiphiles (monoQACs and bisQACs) were rapidly prepared in order to investigate the effects of rigidity of a diamine core structure on antiseptic activity. As anticipated, the bioactivity against a panel of six bacteria including methicillin-resistant Staphylococcus aureus (MRSA) strains was strong for bisQAC structures, and is clearly correlated with the length of non-polar side chains. Modest advantages were noted for amide-containing side chains, as compared with straight-chained alkyl substituents. Surprisingly, antiseptics with more rigidly disposed side chains, such as those in DABCO-12,12, showed the highest level of antimicrobial activity, with single-digit MIC values or better against the entire bacterial panel, including sub-micromolar activity against an MRSA strain.     

A Cubic Silsesquioxane Chemically Modified with a PAMAM Dendrimer G0: an Application in Electro-Oxidation of Ascorbic Acid

Silicon - Octa-(3-chloropropyl) octasilsesquioxane (SS) was functionalized with a PAMAM dendrimer (SP) and characterized by some spectroscopic techniques such as Fourier Transform Infrared, Nuclear...     

Pressing Effects on Yield, Quality, and Nutraceutical Content of Juice, Seeds, and Skins from Black Beauty and Sunbelt Grapes

ABSTRACT: The effects of hot and cold (nonheated) pressing on yield, quality components, and nutraceutical content of juice, grapes, and press fractions (seeds and skins) from Black Beauty ( Vitis rotundifolia ) and Sunbelt ( Vitis labruscana L.) grape cultivars were evaluated. Heating the must before pressing increased juice yield, titratable acidity, red color, brown/yellow pigments, and darkness and decreased the press fraction yield and juice pH in both cultivars. Sunbelt juice from the heated must had the highest yield (786 L/metric ton), red color, brown/yellow pigments, and darkness. Black Beauty nonheated must had the largest press fraction (43%) but the lowest red color, brown/yellow pigments, and darkness in the juice. The juice generally had less total phenolics, total anthocyanins, and oxygen radical absorbance capacity (ORAC) than the whole grapes. The juice from heated Black Beauty and Sunbelt musts had the highest total phenolics (1354 and 1937 mg/L, respectively) and anthocyanins (414 and 513 mg/L, respectively). Although the data for seeds and skins are on a dry basis, the press fractions had higher levels of phenolics and ORAC than the whole grapes and juice. The dried seeds had more phenolics and less anthocyanins than the skins. The highest total phenolic level (95338 mg/kg) equivalents and ORAC level (1100 μmol trolox/g) was in Black Beauty seeds from nonheated must. The skins of nonheated Sunbelt had the highest anthocyanins (11889 mg/kg). Because the press fractions of both cultivars had high ORAC values and total phenolic levels, products with nutraceutical benefits could be developed.     

Measurement of Densification of Zinc Oxide Compacts Using an Optical, Noncontact, Noninvasive Extensometer

An optical noninvasive, noncontact extensometer was used to measure the shrinkage of zinc oxide powder compacts during sintering. Powder compacts were uniaxially and isostatically pressed from micrometer, submicrometer, and nano powders and sintered in a thermal oven at temperatures up to 1100°C. The nanometer-size sample started to densify at ∼400°C, about 200°C below the densification threshold of the micrometer-size sample. The results are in good agreement with those obtained using a contact dilatometer.