Proteinase-catalyzed Hydrolysis of Casein at Atmospheric Pressure and in Supercritical Media

In the presented work, reaction parameters for hydrolysis of casein, catalyzed by Carica papaya latex at atmospheric and high pressure, were optimized. Casein is a remarkably efficient nutrient, supplying not only essential amino acids, but also some carbohydrates, calcium, phosphorus and therefore is very important for the food industry. Different reaction parameters such as temperature, stirring rate, casein and enzyme concentration were studied to found the optimal conditions for the reaction. Reactions were performed at atmospheric pressure; an influence of temperature/pressure on the casein hydrolysis in supercritical carbon dioxide (SC CO2) was also investigated to improve the reaction rates. Higher conversions were achieved when the reactions were performed in SC CO2, even though casein was not soluble in this medium

S-L-G (solid-liquid-gas) phase transition of cocoa butter in supercritical CO2

Phase equilibrium data (solid-liquid-gas) for cocoa butter and carbon dioxide were determined in view if their importance in design of PGSS (particles from gas saturated solutions) micronization process. The mutual solubility in the system cocoa butter/CO2 was measured by the static-analytic method in the temperature range of 30-80 °C and pressure range of 1-30 MPa. The experiments on solid-liquid (S-L) transition for cocoa butter in the presence of carbon dioxide were performed by the modified capillary method in a high pressure optical cell. For the production of finely dispersed cocoa butter by expanding CO2-saturated solutions, the initial guess indicates that the starting conditions should be near the liquefaction curve in order to allow the solid-liquid region to be reached after expansion

New Family of Robust 2D Topological Insulators in van der Waals Heterostructures

We predict a new family of robust two-dimensional (2D) topological insulators in van der Waals heterostructures comprising graphene and chalcogenides BiTeX (X=Cl, Br and I). The layered structures of both constituent materials produce a naturally smooth interface that is conducive to proximity induced new topological states. First principles calculations reveal intrinsic topologically nontrivial bulk energy gaps as large as 70-80 meV, which can be further enhanced up to 120 meV by compression. The strong spin-orbit coupling in BiTeX has a significant influence on the graphene Dirac states, resulting in the topologically nontrivial band structure, which is confirmed by calculated nontrivial Z2 index and an explicit demonstration of metallic edge states. Such heterostructures offer an unique Dirac transport system that combines the 2D Dirac states from graphene and 1D Dirac edge states from the topological insulator, and it offers new ideas for innovative device designs

One-dimensional Topological Edge States of Bismuth Bilayers

The hallmark of a time-reversal symmetry protected topologically insulating state of matter in two-dimensions (2D) is the existence of chiral edge modes propagating along the perimeter of the system. To date, evidence for such electronic modes has come from experiments on semiconducting heterostructures in the topological phase which showed approximately quantized values of the overall conductance as well as edge-dominated current flow. However, there have not been any spectroscopic measurements to demonstrate the one-dimensional (1D) nature of the edge modes. Among the first systems predicted to be a 2D topological insulator are bilayers of bismuth (Bi) and there have been recent experimental indications of possible topological boundary states at their edges. However, the experiments on such bilayers suffered from irregular structure of their edges or the coupling of the edge states to substrate's bulk states. Here we report scanning tunneling microscopy (STM) experiments which show that a subset of the predicted Bi-bilayers' edge states are decoupled from states of Bi substrate and provide direct spectroscopic evidence of their 1D nature. Moreover, by visualizing the quantum interference of edge mode quasi-particles in confined geometries, we demonstrate their remarkable coherent propagation along the edge with scattering properties that are consistent with strong suppression of backscattering as predicted for the propagating topological edge states.Comment: 15 pages, 5 figures, and supplementary materia

Band profiles and band strengths in mixed H2O:CO ices

A laboratory study on the band profiles and band strengths of H2O in CO ice, and vice versa, is presented and interpreted in terms of two models. The results show that a mutual interaction takes place between the two species in the solid, which alters the band positions and band strengths. It is found that the band strengths of the H2O bulk stretch, bending and libration vibrational bands decrease linearly by a factor of up to 2 when the CO concentration is increased from 0 to 80%. By contrast, the band strength of the free OH stretch increases linearly. The results are compared to a recently performed quantitative study on H2O:CO2 ice mixtures. It is shown that for mixing ratios of 1:0.5 H2O:X and higher, the H2O bending mode offers a good tracer to distinguish between CO2 or CO in H2O ice. Additionally, it is found that the band strength of the CO fundamental remains constant when the water concentration is increased in the ice. The integrated absorbance of the 2152 cm-1 CO feature, with respect to the total integrated CO absorption feature, is found to be a good indicator of the degree of mixing of CO in the H2O:CO laboratory ice system. From the change in the H2O absorption band strength in laboratory ices upon mixing we conclude that astronomical water ice column densities on various lines of sight can be underestimated by up to 25% if significant amounts of CO and CO2 are mixed in.Comment: 9 pages, 10 figure

Genotyping of single nucleotide polymorphisms related to attention-deficit hyperactivity disorder

Pharmacological treatment of several diseases, such as attention-deficit hyperactivity disorder (ADHD), presents marked variability in efficiency and its adverse effects. The genotyping of specific single nucleotide polymorphisms (SNPs) can support the prediction of responses to drugs and the genetic risk of presenting comorbidities associated with ADHD. This study presents two rapid and affordable microarray-based strategies to discriminate three clinically important SNPs in genes ADRA2A, SL6CA2, and OPRM1 (rs1800544, rs5569, and rs1799971, respectively). These approaches are allele-specific oligonucleotide hybridization (ASO) and a combination of allele-specific amplification (ASA) and solid-phase hybridization. Buccal swab and blood samples taken from ADHD patients and controls were analyzed by ASO, ASA, and a gold-reference method. The results indicated that ASA is superior in genotyping capability and analytical performance.This research has been funded through projects FEDER MINECO INNPACTO IPT-2011-1132-010000, CTQ/2013/45875R, and PrometeoII/2014/040 (GVA).Tortajada-Genaro, LA.; Mena-Mollá, S.; Niñoles Rodenes, R.; Puigmule, M.; Viladevall, L.; Maquieira Catala, Á. (2016). Genotyping of single nucleotide polymorphisms related to attention-deficit hyperactivity disorder. Analytical and Bioanalytical Chemistry. 408(9):2339-2345. https://doi.org/10.1007/s00216-016-9332-3S233923454089Cortese S. The neurobiology and genetics of Attention-Deficit/Hyperactivity Disorder (ADHD): what every clinician should know. Eur J Paediatr Neurol. 2012;16:422–33.Contini V, Rovaris DL, Victor MM, Grevet EH, Rohde LA, Bau CH. Pharmacogenetics of response to methylphenidate in adult patients with attention-deficit/hyperactivity disorder (ADHD): a systematic review. Eur Neuropsychopharmacol. 2013;23:555–60.Gardiner SJ, Begg EJ. Pharmacogenetics, drug-metabolizing enzymes, and clinical practice. Pharmacol Rev. 2006;58(3):521–90.Abul-Husn NS, Obeng AO, Sanderson SC, Gottesman O, Scott SA. Implementation and utilization of genetic testing in personalized medicine. Pharmacogenomics Pers Med. 2014;7:227.Altman RB, Flockhart D, Goldstein DB, editors. Principles of pharmacogenetics and pharmacogenomics. Cambridge: Cambridge University Press; 2012.Hawi Z, Cummins TDR, Tong J, Johnson B, Lau R, Samarrai W, et al. The molecular genetic architecture of attention deficit hyperactivity disorder. Mol Psychiatry. 2015;20:289–97.Limaye N. Pharmacogenomics, Theranostics and Personalized Medicine-the complexities of clinical trials: challenges in the developing world. Appl Transl Genomics. 2013;2:17–21.Manolio TA, Chisholm RL, Ozenberger B, Roden DM, Williams MS, Wilson R, et al. Implementing genomic medicine in the clinic: the future is here. Genet Med. 2013;15:258–67.Kim S, Misra A. PharmGKB: the Pharmacogenomics Knowledge Base. Annu Rev Biomed Eng. 2007;9:289–320.Lucarelli F, Tombelli S, Minunni M, Marrazza G, Mascini M. Electrochemical and piezoelectric DNA biosensors for hybridisation detection. Anal Chim Acta. 2008;609:139–59.Knez K, Spasic D, Janssen KP, Lammertyn J. Emerging technologies for hybridization based single nucleotide polymorphism detection. Analyst. 2014;139:353–70.Choi JY, Kim YT, Byun JY, Ahn J, Chung S, Gweon DG, et al. Integrated allele-specific polymerase chain reaction–capillary electrophoresis microdevice for single nucleotide polymorphism genotyping. Lab Chip. 2012;12:5146–54.Ragoussis J. Genotyping Technologies for Genetic Research. Annu Rev Genomics Hum Genet. 2009;10:117–33.Sethi D, Gandhi RP, Kuma P, Gupta KC. Chemical strategies for immobilization of oligonucleotides. Biotechnol J. 2009;4:1513–29.Bañuls MJ, Morais SB, Tortajada-Genaro LA, Maquieira A. Microarray Developed on Plastic Substrates. Microarray Technology: Methods and Applications, 2016; 37-51.Tortajada-Genaro LA, Rodrigo A, Hevia E, Mena S, Niñoles R, Maquieira A. Microarray on digital versatile disc for identification and genotyping of Salmonella and Campylobacter in meat products. Anal Bioanal Chem. 2015;407:7285–94.Kieling C, Genro JP, Hutz MH, Rohde LA. A current update on ADHD pharmacogenomics. Pharmacogenomics. 2010;11:407–19.Kim BN, Kim JW, Cummins TD, Bellgrove MA, Hawi Z, Hong SB, et al. Norepinephrine genes predict response time variability and methylphenidate-induced changes in neuropsychological function in attention deficit hyperactivity disorder. J Clin Psychopharmacol. 2013;33:356–62.Carpentier PJ, Arias Vasquez A, Hoogman M, Onnink M, Kan CC, Kooij JJS, et al. Shared and unique genetic contributions to attention deficit/hyperactivity disorder and substance use disorders: A pilot study of six candidate genes. Eur Neuropsychopharmacol. 2013;23:448–57.Zhang Y, Haraksingh R, Grubert F, Abyzov A, Gerstein M, Weissman S, et al. Child development and structural variation in the human genome. Child Dev. 2013;84:34–48.Asari M, Watanabe S, Matsubara K, Shiono H, Shimizu K. Single nucleotide polymorphism genotyping by mini-primer allele-specific amplification with universal reporter primers for identification of degraded DNA. Anal Biochem. 2009;386:85–90.Choi JY, Kim YT, Ahn J, Kim KS, Gweon DG, Seo TS. Integrated allele-specific polymerase chain reaction–capillary electrophoresis microdevice for single nucleotide polymorphism genotyping. Biosens Bioelectron. 2012;35:327–34.Konstantou JK, Ioannou PC, Christopoulos TK. Dual-allele dipstick assay for genotyping single nucleotide polymorphisms by primer extension reaction. Eur J Hum Genet. 2009;17:105–11.Sebastian T, Cooney CG, Parker J, Qu P, Perov A, Golova JB, et al. Integrated amplification microarray system in a lateral flow cell for warfarin genotyping from saliva. Clin Chim Acta. 2014;429:198–205

The antioxidant enzyme peroxiredoxin-2 is depleted in lymphocytes seven days after ultra-endurance exercise

Purpose: Peroxiredoxin-2 (PRDX-2) is an antioxidant and chaperone-like protein critical for cell function. This study examined whether the levels of lymphocyte PRDX-2 are altered over one month following ultra-endurance exercise. Methods: Nine middle-aged men undertook a single-stage, multi-day 233 km (145 mile) ultra-endurance running race. Blood was collected immediately before (PRE), upon completion/retirement (POST), and following the race at DAY 1, DAY 7 and DAY 28. Lymphocyte lysates were examined for PRDX-2 by reducing SDS-PAGE and western blotting. In a sub-group of men who completed the race (n = 4) PRDX-2 oligomeric state (indicative of redox status) was investigated. Results: Ultra-endurance exercise caused significant changes in lymphocyte PRDX-2 (F (4,32) 3.409, p=0.020, ?(2) =0.299): seven-days after the race, PRDX-2 levels in lymphocytes had fallen to 30% of pre-race values (p=0.013) and returned to near-normal levels at DAY 28. Non-reducing gels demonstrated that dimeric PRDX-2 (intracellular reduced PRDX-2 monomers) was increased in 3 of 4 race completers immediately post-race, indicative of an "antioxidant response". Moreover, monomeric PRDX-2 was also increased immediately post-race in 2 of 4 race-completing subjects, indicative of oxidative damage, which was not detectable by DAY 7. Conclusions: Lymphocyte PRDX-2 was decreased below normal levels 7 days after ultra-endurance exercise. Excessive accumulation of reactive oxygen species induced by ultra-endurance exercise may underlie depletion of lymphocyte PRDX-2 by triggering its turnover after oxidation. Low levels of lymphocyte PRDX-2 could influence cell function and might, in part, explain reports of dysregulated immunity following ultra-endurance exercise

Obesity-Related Oxidative Stress: the Impact of Physical Activity and Diet Manipulation

Obesity-related oxidative stress, the imbalance between pro-oxidants and antioxidants (e.g., nitric oxide), has been linked to metabolic and cardiovascular disease, including endothelial dysfunction and atherosclerosis. Reactive oxygen species (ROS) are essential for physiological functions including gene expression, cellular growth, infection defense, and modulating endothelial function. However, elevated ROS and/or diminished antioxidant capacity leading to oxidative stress can lead to dysfunction. Physical activity also results in an acute state of oxidative stress. However, it is likely that chronic physical activity provides a stimulus for favorable oxidative adaptations and enhanced physiological performance and physical health, although distinct responses between aerobic and anaerobic activities warrant further investigation. Studies support the benefits of dietary modification as well as exercise interventions in alleviating oxidative stress susceptibility. Since obese individuals tend to demonstrate elevated markers of oxidative stress, the implications for this population are significant. Therefore, in this review our aim is to discuss (i) the role of oxidative stress and inflammation as associated with obesity-related diseases, (ii) the potential concerns and benefits of exercise-mediated oxidative stress, and (iii) the advantageous role of dietary modification, including acute or chronic caloric restriction and vitamin D supplementation