Seguimiento online de la conductividad eléctrica del vino inducido por ultrasonido

We assessed the effects of ultrasonic frequency, power, temperature and exposure time on the electric conductivity (EC) of wine to evaluate the feasibility of the online EC monitoring as an indicator to reflect the changes of wine quality under the ultrasound irradiation. Results showed that the continuously monitored curve of EC was significantly different from the values recorded at the beginning and end of sonication. An abrupt rise and a rapid drop of wine EC were observed at the start and end points of sonication, respectively, in all working conditions. With regards to the assayed wine temperatures, the effect exerted by this parameter on EC before sonication was totally different from that observed when the samples were cooled down after ultrasound treatment. All in all, these results suggest that the online EC monitoring of wine may be used as an efficient indicator to control and reflect the real changes of wine under ultrasound treatment.Hemos estudiado los efectos de la frecuencia de ultrasonido, la potencia, la temperatura y el tiempo de exposición en la conductividad eléctrica (EC) del vino para evaluar la viabilidad del seguimiento EC online como indicador para reflejar los cambios en la calidad del vino bajo irradiación de ultrasonido. Los resultados mostraron que la curva de EC supervisada en continuo fue significativamente diferente de los valores registrados al principio y al final de la sonicación. Se observaron un aumento brusco y una rápida caída de EC del vino al principio y al final de la sonicación, respectivamente, para todas las condiciones estudiadas. En referencia a las temperaturas testadas del vino, el efecto ejercido por este parámetro en EC antes de la sonicación fue totalmente distinto de aquel observado cuando se enfriaron las muestras después del tratamiento de ultrasonido. En resumen, estos resultados sugieren que el seguimiento online de EC del vino podría ser utilizado como un indicador eficiente para controlar y reflejar los cambios reales en el vino con el uso de tratamiento de ultrasonido.National Natural Science Foundation of China [grant number 31101324]Natural Science Foundation of Shaanxi Province, China [grant number 2015JM3097]Technology Transfer Promotion Project of Xi’an, Shaanxi Province, China [grant number CXY1434(5)]Fundamental Research Funds for the Central Universities of China [grant number GK201302039], [grant number GK201404006], [grant number GK201505128

Estudio preliminar sobre el efecto del ultrasonido en las propiedades fisicoquímicas del vino tinto

Ultrasound is regarded as a potential alternative method for improving the quality of some wines. This study was initiated with the objective of evaluating the effects of ultrasound on some important physicochemical properties of red wine such as chromatic characteristics (CC), electrical conductivity (EC), pH, titratable acidity (TA), total phenolic compounds (TPCs) and DPPH (1,1-diphenyl-2-picryl-hydrazyl) free radical scavenging activity (DFRSA). The operational parameters assessed were ultrasound power, ultrasound frequency, exposure time and bath temperature. Results illustrated that there were significant changes in CC, EC and TPC while pH and TA hardly changed except for samples treated at high temperatures. DFRSA was correlated to TPC during ultrasonic treatment. Application of principal component analysis to the experimental data suggested that exposure time was the factor with the greatest ability to induce changes on wine. Results suggested that ultrasound may be applied to improve some physicochemical properties of red wine.El ultrasonido se considera uno de los métodos alternativos potenciales para mejorar la calidad de algunos vinos. Se comenzó este estudio con el objetivo de evaluar los efectos del ultrasonido en algunas de la propiedades fisicoquímicas importantes del vino tinto como son: las características cromáticas (CC), la conductividad eléctrica (EC), el pH, la acidez (TA), los compuestos fenólicos totales (TPC) y el DPPH (1,1-difenil-2-picrilhidrazil) de actividad de eliminación de radicales libres (DFRSA). Los parámetros operacionales examinados fueron: la potencia de ultrasonido, la frecuencia de ultrasonido, el tiempo de exposición y la temperatura de baño. Los resultados ilustraron la existencia de cambios significativos en CC, EC y TPC, mientras que el pH y TA prácticamente no cambiaron excepto en las muestras tratadas con altas temperaturas. DFRSA tuvo correlación con TPC durante el tratamiento con ultrasonido. La aplicación de análisis de componentes principales a los datos experimentales sugirió que el tiempo de exposición era el factor con mayor habilidad para inducir cambios en el vino. Los resultados sugirieron que el ultrasonido podría aplicarse para mejorar algunas de las propiedades fisicoquímicas del vino tinto.National Natural Science Foundation of China [No. 31101324]Natural Science Foundation of Shaanxi Province, China [No. 2015JM3097]Technology Transfer Promotion Project of Xi’an, Shaanxi Province, China [No.CXY1434(5)]Fundamental Research Funds for the Central Universities of China [Nos. GK201302039, GK201404006

Preparation and Characterization of PMMA and its Derivative via RAFT Technique in the Presence of Disulfide as a Source of Chain Transfer Agent

Poly(methyl methacrylate) (PMMA) were synthesized by using chain transfer agents(CTA), S-1-Dodecyl-S′-(α,α′-dimethyl-α-acetic acid) trithiocarbonate (MTTCD), S,S′-bis (2-hydroxyethyl-2′-dimethylacrylate) trithiocarbonate (BDATC), 2-cyanoprop-2-yl dithiobenzoate (CPDB) respectively, through the reversible addition fragmentation chain transfer (RAFT) polymerization under a range of synthesis conditions. The results indicated that the structure of the end-group of RAFT agents had significant effects on the ability to control polymerization. Compared with MTTCD and CPDB, BDATC can provide better control over the relative molecular mass, distribution and polymerization of PMMA. The derived well-controlled block copolymer PMMA-b-PDMAEMA and PMMA-b-PDMAEA were also successfully prepared by using N, N-dimethylaminoethy acrylate (DMAEA) or N, N-dimethylaminoethyl methacrylate (DMAEMA) as the second monomer. The chemical composition and structure of the products were characterized by FTIR, 1HNMR, XRD and DSC. CO2 and N2 permeation performance of the PMMA-b-PDMAEA/PS composite membranes were tested at different pressure. The results showed that the resulted composited membrane had a CO2 permeation rate of 3.68×10-5cm3 (STP) cm-2s-1cmHg-1, a N2 permeation rate of 1.78×10-7 cm3 (STP) cm-2s-1cmHg-1 and an ideal CO2/ N2 selectivity of 206.6 at a feed gas pressure of 7.6 cmHg and 30 oC

Di-μ-sulfato-bis­[diaqua­(1H-imidazo[4,5-f][1,10]phenanthroline)iron(II)] dihydrate

The title dinuclear FeII complex, [Fe2(SO4)2(C13H8N4)2(H2O)4]·2H2O, is centrosymmetric. Two sulfate anions bridge two FeII cations to form the binuclear complex. Each FeII cation is coordinated by two N atoms from a 1H-imidazo[4,5-f][1,10]phenanthroline (IP) ligand, two O atoms from two sulfate anions and two water mol­ecules in a distorted octa­hedral geometry. Extensive O—H⋯O, N—H⋯O and O—H⋯N hydrogen bonding is present in the crystal structure. Weak π–π stacking is observed between parallel IP ring systems, the face-to-face separation being 3.428 (14) Å

Effects of painful stimulation and acupuncture on attention networks in healthy subjects

Pain is a subjective sensory and emotional experience, and it has been reported that many different brain regions are regulated by pain, and that pain can impact attention. Acupuncture is an important treatment component of Chinese traditional medicine, and has been used for thousands of years to treat a wide variety of conditions. Although several studies have shown that acupuncture improves consciousness, the precise impact of both acupuncture and painful stimulation on attention is unclear. Are all of the attention networks modulated, or do these stimuli act on a specific network? Is the effect of painful stimulation similar to that of acupuncture? We administered the attention network test to 30 participants (15 males) to investigate the relative efficiencies of three independent attention networks (alerting, orienting, and executive control networks) under three conditions: baseline, after painful stimulation, and after acupuncture. The degree of pain experienced was assessed on a horizontally oriented visual analogue scale. The results showed that painful stimulation and acupuncture had similar effects on the orienting and executive control networks; however, there was a significantly different effect between the three conditions on the alerting network. In conclusion, (1) painful stimulation can selectively impact attention; (2) acupuncture can also selectively impact attention; i.e., both have selective influences on the alerting and executive control networks, but not on the orienting network; (3) the effects of acupuncture and painful stimulation are not identical. The mechanisms by which painful stimulation and acupuncture influence attention warrant further research

Dorsal Striatum Dopamine Levels Fluctuate Across the Sleep–Wake Cycle and Respond to Salient Stimuli in Mice

Dopamine is involved in numerous neurological processes, and its deficiency has been implicated in Parkinson’s disease, whose patients suffer from severe sleep disorders. Destruction of nigrostriatal dopaminergic neurons or dorsal striatum disrupts the sleep–wake cycle. However, whether striatal dopamine levels correlate with vigilance states still remains to be elucidated. Here, we employed an intensity-based genetically encoded dopamine indicator, dLight1.1, to track striatal dopamine levels across the spontaneous sleep–wake cycle and the dopaminergic response to external stimuli. We found that the striatal dLight1.1 signal was at its highest during wakefulness, lower during non-rapid eye movement (non-REM or NREM) sleep, and lowest during REM sleep. Moreover, the striatal dLight1.1 signal increased significantly during NREM sleep-to-wake transitions, while it decreased during wake-to-NREM sleep transitions. Furthermore, different external stimuli, such as sudden door-opening of the home cage or cage-change to a new environment, caused striatal dopamine release, whereas an unexpected auditory tone did not. Finally, despite both modafinil and caffeine being wake-promoting agents that increased wakefulness, modafinil increased striatal dopamine levels while caffeine did not. Taken together, our findings demonstrated that striatal dopamine levels correlated with the spontaneous sleep–wake cycle and responded to specific external stimuli as well as the stimulant modafinil