Characterization, stability and solubility of co-amorphous systems of glibenclamide and L-arginine at different pH

Purpose: To investigate the stability and solubility of co-amorphous systems of glibenclamide (GBC) with L-arginine (L-Arg) at different pH values. Methods: Three co-amorphous solids of GBC and L-Arg were obtained by fast solvent evaporation using 2:1, 1:1 and 1:2 stoichiometries. All co-amorphous systems were characterized by XRPD, FTIR, RAMAN and NMR-solid state as well as thermal techniques such as DSC and TGA. The stability of coamorphous systems was evaluated by indicative stability and stability in relevant physiological media was measured at different pH values. Results: The chemical characterization suggest that there was no proton transference between L-Arg and GBC indicative of co-amorphous solids. Stability studies showed that all the co-amorphous solids are unstable under humid conditions and only the co-amorphous system of GBC: L-Arg 1:2 was stable in all the pH values tested. Solubility studies at different pH values showed that the co-amorphous GBC: L-Arg 1:1 and 1:2, showed increasing solubility values even at pH < 7 (0.6468 mg/mL at pH 1.2 for coamorphous GBC: L-Arg 1:2 at the first hour) where free GBC was not soluble. Conclusion: Co-amorphous systems of GBC and L-Arg, is an interesting strategy to increase the solubility of poorly-soluble drugs at acidic pH values Keywords: Co-amorphous; Glibenclamide; L-Arginine; Solubility; Stabilit

Evaluación de un método sensorial sencillo y efectivo para determinar la rancidez en aceite de soja

The purpose of this study was to evaluate the efficacy of the 2 Alternative Forced Choice (2-AFC) sensory method in detecting rancidity in soybean oils. Additionally, correlations between the physico-chemical quality and the sensory attributes of edible soybean oils were studied. Soybean oil samples from four different plants were analyzed for their fatty acid profile, Free fatty acid (FFA), Anisidine Value (AV), Peroxide Value (PV), Conjugated Dienes (CD), Colour, Rancimat and TOTOX. The sensory attributes of the oils were measured using The American Oil Chemists Society (AOCS) sensory method and additionally, rancidity was assessed using the 2-AFC sensory method. All oil samples fit the quality control criteria for edible soybean oil. The 2-AFC The purpose of this study was to evaluate the efficacy of the 2 Alternative Forced Choice (2-AFC) sensory method in detecting rancidity in soybean oils. Additionally, correlations between the physico-chemical quality and the sensory attributes of edible soybean oils were studied. Soybean oil samples from four different plants were analyzed for their fatty acid profile, Free fatty acid (FFA), Anisidine Value (AV), Peroxide Value (PV), Conjugated Dienes (CD), Colour, Rancimat and TOTOX. The sensory attributes of the oils were measured using The American Oil Chemists Society (AOCS) sensory method and additionally, rancidity was assessed using the 2-AFC sensory method. All oil samples fit the quality control criteria for edible soybean oil. The 2-AFC  method was sensitive to small differences in rancidity. Differences in anisidine value and Rancimat were correlated to the difference in rancidity (d') among oilsEl propósito de este trabajo fue evaluar la eficacia de la prueba de selección forzada de dos alternativas (2-AFC) para determinar la rancidez en aceite de soja. La correlación entre la calidad química y los atributos sensoriales de los aceites fue el segundo objetivo del trabajo. El perfil de ácidos grasos, ácidos grasos libres (AGL), índice de anisidina (VA), índice de peróxidos (VP), dienos conjugados (DC), color, Rancimat y TOTOX se midieron en aceites de cuatro plantas procesadoras de aceite comestible de soja. Los atributos sensoriales del aceite se midieron utilizando la prueba oficial de la Sociedad Americana de Químicos de Aceites (AOCS) y el atributo de rancidez se evaluó usando la prueba 2-AFC. Todos los aceites satisficieron los criterios de calidad química para los aceites de soja. El método sensorial 2-AFC fue eficaz en determinar diferencias pequeñas en rancidez. Se encontró correlación entre los valores de anisidina y Rancimat y las diferencias sensoriales en rancidez (d')

Recent smell loss is the best predictor of COVID-19 among individuals with recent respiratory symptoms

In a preregistered, cross-sectional study we investigated whether olfactory loss is a reliable predictor of COVID-19 using a crowdsourced questionnaire in 23 languages to assess symptoms in individuals self-reporting recent respiratory illness. We quantified changes in chemosensory abilities during the course of the respiratory illness using 0-100 visual analog scales (VAS) for participants reporting a positive (C19+; n=4148) or negative (C19-; n=546) COVID-19 laboratory test outcome. Logistic regression models identified univariate and multivariate predictors of COVID-19 status and post-COVID-19 olfactory recovery. Both C19+ and C19- groups exhibited smell loss, but it was significantly larger in C19+ participants (mean±SD, C19+: -82.5±27.2 points; C19-: -59.8±37.7). Smell loss during illness was the best predictor of COVID-19 in both univariate and multivariate models (ROC AUC=0.72). Additional variables provide negligible model improvement. VAS ratings of smell loss were more predictive than binary chemosensory yes/no-questions or other cardinal symptoms (e.g., fever). Olfactory recovery within 40 days of respiratory symptom onset was reported for ~50% of participants and was best predicted by time since respiratory symptom onset. We find that quantified smell loss is the best predictor of COVID-19 amongst those with symptoms of respiratory illness. To aid clinicians and contact tracers in identifying individuals with a high likelihood of having COVID-19, we propose a novel 0-10 scale to screen for recent olfactory loss, the ODoR-19. We find that numeric ratings ≤2 indicate high odds of symptomatic COVID-19 (4<10). Once independently validated, this tool could be deployed when viral lab tests are impractical or unavailable

Biochemical and histopathological effects of dietary oxidized cholesterol products in rats

Cholesterol is present in a great variety of foods of animal origin. Oxidation of this substance produces cholesterol oxidation products (COP´s) that have been associated with the genesis of chronic degenerative diseases such as atherosclerosis. This chronic disease is characterized by histological changes that reflect damage to the arterial structure because of accumulation of lipids that contain oxidized cholesterol in the form of an oxidized low density lipoprotein. The purpose of this work was to study the biochemical and histological effect of dietary COP´s in rats. Male Wistar albino rats (5 weeks old) were obtained from Harlan (Mexico City); the animals were randomly divided into three groups of ten rats each. Standard rat chow was supplemented with either 1% (w/w) pure cholesterol or 1% oxidized cholesterol and fed to rats for 8 weeks. Control animals were fed standard rat chow. At the end of 8 weeks, the lipid profile was determined in serum; the aorta, liver and kidneys were excised immediately, frozen with liquid nitrogen, and held at -56°C. The histological study was carried out using conventional hematoxilin – eosin and Oil Red O techniques. The administration of dietary COP´s altered those biochemical parameters involved in lipid metabolism that are associated with atherogenesis in rats, namely, total cholesterol, triglycerides, and low density lipoproteins. The COP´s modified the tissue structure of the aorta where the presence of lipids was demonstrated in the inner coat; in the liver and kidney, COPs caused infiltration of lymphocytes, fibrosis and steatosis. Further investigations will provide information regarding the consumption of dietary COP´s, their implications in oxidative stress, and their participation as gene regulators

Cholesterol oxidation and astaxanthin degradation in shrimp during sun drying and storage

Dried salted shrimps are made from raw shrimps, which are cooked and dried under direct sunlight. The preparation and storage include treatments and conditions that can promote oxidative changes in different components. The aim of this study was to monitor the formation of major cholesterol oxidation products and the changes in the astaxanthin content and fatty acid profile in dried salted shrimp during cooking, sun drying and storage. During sun drying, most of the astaxanthin (75%) was degraded in cooked shrimp, while cholesterol oxidation products (COPs) showed a dramatic increase (8.6-fold), reaching a total concentration of 372.9 ± 16.3 μg/g of lipids. Further storage favoured both astaxanthin degradation (83%) and COPs formation (886.6 ± 97.9 μg/g of lipids after 90 days of storage). The high degradation of astaxanthin and the elevated formation of COPs during sun drying and storage indicate the necessity to re-evaluate the processing and storage conditions of salted dried shrimp

Thermophilic Bacteria From Mexican Thermal Environments: Isolation and Potential Applications

Extremophiles are microorganisms that possess application possibilities in several industrial fields, including agricultural, chemical, laundry, pharmaceutical, food, petroleum and bioremediation. This work reports the isolation of 19 thermophilic, alkalitolerant and halotolerant bacterial strains from two thermal sites in Veracruz, México: El Carrizal thermal pool and Los Baños hot spring. These strains belong to the Geobacillus, Anoxybacillus and Aeribacillus genera. The strains produce lipases, proteases, and amylases under thermophilic conditions. They may have good potential for application in microbial enhanced oil recovery, since they are thermophilic and halotolerant, produce exopolymers (up to 11.8 mg/mg) and acids, show emulsifying activity (E24 up to 7.5%), and are able to grow in kerosene as carbon source; these strains may also be used in biodesulphurization since they can grow in dibenzothiophene producing 2-hydroxybiphenyl under thermophilic conditions (up to 2.9 mg/L)

Where Brain, Body and World Collide

The production cross section of electrons from semileptonic decays of beauty hadrons was measured at mid-rapidity (|y| < 0.8) in the transverse momentum range 1 < pt < 8 Gev/c with the ALICE experiment at the CERN LHC in pp collisions at a center of mass energy sqrt{s} = 7 TeV using an integrated luminosity of 2.2 nb^{-1}. Electrons from beauty hadron decays were selected based on the displacement of the decay vertex from the collision vertex. A perturbative QCD calculation agrees with the measurement within uncertainties. The data were extrapolated to the full phase space to determine the total cross section for the production of beauty quark-antiquark pairs