42 research outputs found
Interaction Between Air Plasma-Produced Aqueous 1O2 and the Spin Trap DMPO in Electron Spin Resonance
A series of electron spin resonance (ESR) experiments is done to quantitatively measure the concentrations of aqueous 1O2 and OH produced by a surface micro-discharge air plasma device. 1O2 is tested to be existed in the plasma treated solution by using the spin trap of TEMP. However, the unexpected DMPOX spectrum is observed in measuringOH by the spin trap of 5,5-Dimethyl-1-Pyrroline-N-Oxide (DMPO). With more chemical scavenger experiments, it is found that removal of aqueous 1O2 leads to the disappearance of DMPOX in ESR. Therefore, the generation of DMPOX is directly related to the oxidation of DMPO by plasma-produced aqueous 1O2. This oxidation process and interactions between DMPO and chemical scavengers used in experiments can all be well explained by a proposed reaction mechanism. The revelation of interactions between aqueous 1O2 and the spin trap DMPO shows that the observation of spectra of DMPOX in the ESR measurement can be regarded as a marker of high concentrations of plasma-produced 1O2 in liquid. These results also prove the existence of interactions between spin traps and non-targeted plasma-produced reactive species in ESR experiments. Also, these results have offered a better understanding of the use of spin traps such as DMPO in the plasma-induced highly oxidative aqueous environment. Published by AIP Publishing
Motor expertise modulates unconscious rather than conscious executive control
Background Executive control, the ability to regulate the execution of a goal-directed task, is an important element in an athlete’s skill set. Although previous studies have shown that executive control in athletes is better than that in non-athletes, those studies were mainly confined to conscious executive control. Many recent studies have suggested that executive control can be triggered by the presentation of visual stimuli without participant’s conscious awareness. However, few studies have examined unconscious executive control in sports. Thus, the present study investigated whether, similar to conscious executive control, unconscious executive control in table tennis athletes is superior to that in non-athletes. Methods In total, 42 age-matched undergraduate students were recruited for this study; 22 nonathletic students lacking practical athletic experience comprised one group, and 20 table tennis athletes with many years of training in this sport comprised a second group. Each participant first completed an unconscious response priming task, the unconscious processing of visual-spatial information, and then completed a conscious version of this same response priming task. Results Table tennis athletes showed a significant response priming effect, whereas non-athletes did not, when participants were unable to consciously perceive the visual-spatial priming stimuli. In addition, the number of years the table tennis athletes had trained in this sport (a measure of their motor expertise) was positively correlated with the strength of the unconscious response priming effect. However, both table tennis athletes and non-athletes showed a response priming effect when the primes were unmasked and the participants were able to consciously perceive the visual-spatial priming stimuli. Conclusion Our results suggest that motor expertise modulates unconscious, rather than conscious, executive control and that motor expertise is positively correlated with unconscious executive control in table tennis athletes
Donor Platelet Plasma Components Inactivate Sensitive and Multidrug Resistant Acinetobacter Baumannii Isolates
Acinetobacter baumannii is an environmentally resilient healthcare-associated opportunistic pathogen responsible for infections at many body sites. In the last 10 years, clinical strains resistant to many or all commonly used antibiotics have emerged globally. With few antimicrobial agents in the pharmaceutical pipeline, new and alternative agents are essential. Platelets secrete a large number of proteins, including proteins with antimicrobial activity. In a previous study, we demonstrated that donor platelet supernatants and plasma significantly inhibited the growth of a reference strain of A. baumannii in broth and on skin. This inhibition appeared to be unrelated to the platelet activation state. In this study, we demonstrate that this growth inhibition extends to clinical multidrug resistant isolates. We also demonstrate that there is no relationship between this activity and selected platelet-derived antimicrobial proteins. Instead, the donor plasma components complement and alpha-2 macroglobulin are implicated
Gene Electro Transfer of Plasmid Encoding Vascular Endothelial Growth Factor for Enhanced Expression and Perfusion in the Ischemic Swine Heart
Myocardial ischemia can damage heart muscle and reduce the heart\u27s pumping efficiency. This study used an ischemic swine heart model to investigate the potential for gene electro transfer of a plasmid encoding vascular endothelial growth factor for improving perfusion and, thus, for reducing cardiomyopathy following acute coronary syndrome. Plasmid expression was significantly greater in gene electro transfer treated tissue compared to injection of plasmid encoding vascular endothelial growth factor alone. Higher gene expression was also seen in ischemic versus non-ischemic groups with parameters 20 Volts (
Antioxidant activities of kombucha prepared from three different substrates and changes in content of probiotics during storage
Study on Maneuvering Target On-axis Tracking Algorithm of Modified Current Statistical Model
Aiming at the model adaptability and the filter precision on the maneuvering target on-axis tracking, The paper put forward a filter algorithm based on modified current statistical model. The algorithm can enhance the model adaptability to the weak and non-maneuvering maneuvering target. The method uses Unscented Kalman Filter to obtain the importance density function of each particle, improves the Particle Filter estimation performance.By applying the proposed algorithm to the on-axis tracking system, the simulation results demonstrate that algorithm can effectively improve filter performance and tracking precision
Effect of Heat Treatment Temperature on Martensitic Transformation and Superelasticity of the Ti49Ni51 Shape Memory Alloy
The martensitic transformation and superelasticity of Ti49Ni51 shape memory alloy heat-treatment at different temperatures were investigated. The experimental results show that the microstructures of as-cast and heat-treated (723 K) Ni-rich Ti49Ni51 samples prepared by rapidly-solidified technology are composed of B2 TiNi phase, and Ti3Ni4 and Ti2Ni phases; the microstructures of heat-treated Ti49Ni51 samples at 773 and 823 K are composed of B2 TiNi phase, and of B2 TiNi and Ti2Ni phases, respectively. The martensitic transformation of as-cast Ti49Ni51 alloy is three-stage, A→R→M1 and R→M2 transformation during cooling, and two-stage, M→R→A transformation during heating. The transformations of the heat-treated Ti49Ni51 samples at 723 and 823 K are the A↔R↔M/A↔M transformation during cooling/heating, respectively. For the heat-treated alloy at 773 K, the transformations are the A→R/M→R→A during cooling/heating, respectively. For the heat-treated alloy at 773 K, only a small thermal hysteresis is suitable for sensor devices. The stable σmax values of 723 and 773 K heat-treated samples with a large Wd value exhibit high safety in application. The 773 and 823 K heat-treated samples have large stable strain–energy densities, and are a good superelastic alloy. The experimental data obtained provide a valuable reference for the industrial application of rapidly-solidified casting and heat-treated Ti49Ni51 alloy
Effects of Physical Activity Level on Attentional Networks in Young Adults
Although physical activity is associated with better attentional functioning in elderly populations or in specific clinical populations, the association between physical activity level and attention has been less studied in young adult populations. Thus, the purpose of this study was to investigate whether the positive effects of physical activity on attentional networks extend to young adults. In total, 57 college students were recruited and assigned to one of three groups of physical activity levels (high, moderate, and low) based on their self-reported exercise. Each participant completed the Attention Network Test to evaluate the efficiency of three components of attention: alerting, orienting, and executive control. Compared with the low physical activity group, both the high and moderate physical activity groups exhibited better executive control. In addition, the efficiency of the executive control network was positively correlated with physical activity. By contrast, no statistically significant differences were detected among these three groups for the functioning of the alerting or orienting networks. These findings suggested that physical activity had a positive effect on attention in young adults, with the benefit primarily observed for the executive control component rather than for the alerting and orienting components of attention
An Analytical Solution for Unsteady Aerodynamic Forces on Streamlined Box Girders with Coupled Vibration
This paper is a contribution to analyzing the aerodynamic forces on a streamlined box girder (SBG) with coupled vibration in a potential flow. The key enabling step was to assume that the normal velocity of the airflow at an arbitrary point on the surface of the SBG was equal to the normal velocity of the surface motion. The aerodynamic drag force, lift force, and pitching moment were expressed as functions of the motion state of the SBG and the SBG’s shape-related parameters. To investigate the applicability of this force model, the analytical solution at various angles of attack was compared with a numerical simulation in a viscous flow. The results imply that the amplitude of the analytical lift force and pitching moment agree well with the numerical results under the angles of attack of 0° and ±3°. Furthermore, the analytical drag force effectively predicts the second-order phenomenon resulting from the multiplication of the vertical and torsional vibration velocities. As a consequence, the present analytical solution provides an effective method for analyzing the aerodynamic forces acting on SBGs with coupled vibration