Valorization of Glycerol through Plasma-Induced Transformation into Formic Acid.

To cope with climate change issues, a significant shift is required in worldwide energy sources. Hydrogen and bioenergy are being considered as alternatives toward a carbon neutral society, making formic acid - a hydrogen carrying product of glycerol - of interest for the valorization of glycerol. Here we investigate the plasma-induced transformation of glycerol in an aqueous nanosecond repetitively pulsed discharge reactor. We found that the water content in the aqueous mixture fulfilled a crucial role in both the gas phase (as a source of OH radicals) and the liquid phase (as a promotor of the dissolved OH radical's mobility and reactivity). The formic acid produced was linearly proportional to the specific input energy, and the most cost-effective production of formic acid was found with 10 % v/v glycerol in the aqueous mixture. A plausible reaction pathway was proposed, consisting of the OH radical-driven dehydrogenation and dehydration of glycerol. The results provide a fundamental understanding of plasma-induced transformation of glycerol to formic acid and insights for future practical applications.

Kinetic Study for Plasma Assisted Cracking of NH3: Approaches and Challenges.

Ammonia is considered as one of the promising hydrogen carriers toward a sustainable world. Plasma assisted decomposition of NH3 could provide cost- and energy-effective, low-temperature, on-demand (partial) cracking of NH3 into H2. Here, we presented a temperature-dependent plasma-chemical kinetic study to investigate the role of both electron-induced reactions and thermally induced reactions on the decomposition of NH3. We employed a plasma-chemical kinetic model (KAUSTKin), developed a plasma-chemical reaction mechanism for the numerical analysis, and introduced a temperature-controlled dielectric barrier discharge reactor for the experimental investigation using 1 mol % NH3 diluted in N2. As a result, we observed the plasma significantly lowered the cracking temperature and found that the plasma-chemical mechanism should be further improved to better predict the experiment. The commonly used rates for the key NH3 pyrolysis reaction (NH3 + M ↔ NH2 + H + M) significantly overpredicted the recombination rate at temperatures below 600 K. Furthermore, the other identified shortcomings in the available data are (i) thermal hydrazine chemistry, (ii) electron-scattering cross-section data of NxHy, (iii) electron-impact dissociation of N2, and (iv) dissociative quenching of excited states of N2. We believe that the present study will spark fundamental interest to address these shortcomings and contribute to technical advancements in plasma assisted NH3 cracking technology.

Stimuli-Responsive Adaptive Nanotoxin to Directly Penetrate the Cellular Membrane by Molecular Folding and Unfolding.

Biological nanomachines, including proteins and nucleic acids whose function is activated by conformational changes, are involved in every biological process, in which their dynamic and responsive behaviors are controlled by supramolecular recognition. The development of artificial nanomachines that mimic the biological functions for potential application as therapeutics is emerging; however, it is still limited to the lower hierarchical level of the molecular components. In this work, we report a synthetic machinery nanostructure in which actuatable molecular components are integrated into a hierarchical nanomaterial in response to external stimuli to regulate biological functions. Two nanometers core-sized gold nanoparticles are covered with ligand layers as actuatable components, whose folding/unfolding motional response to the cellular environment enables the direct penetration of the nanoparticles across the cellular membrane to disrupt intracellular organelles. Furthermore, the pH-responsive conformational movements of the molecular components can induce the apoptosis of cancer cells. This strategy based on the mechanical motion of molecular components on a hierarchical nanocluster would be useful to design biomimetic nanotoxins.

Association Between Hearing Loss and Postural Instability in Older Korean Adults.

Importance: Hearing loss is one of the most frequently occurring sensory disabilities worldwide. The association between hearing loss and postural instability in an older population remains to be studied. Objective: To determine whether the odds of postural instability increase with the degree of hearing loss and to suggest criteria for hearing rehabilitation for postural instability. Design, Setting, and Participants: This cross-sectional population-based study of 3864 participants 40 years and older with hearing loss used data from 2010 through 2012 in the fifth edition of the Korea National Health and Nutrition Examination Survey, a nationwide survey of South Korea. Pure tone audiometry was performed on both the left and right sides and each hearing grade of each side was classified into 1 of 3 subcategories: normal hearing, mild hearing loss, or moderate hearing loss (moderate hearing loss or worse). Postural instability was defined as the failure to remain standing on a foam pad surface with feet 10 cm apart with arms folded and hands cupping the elbows and eyes closed. A binomial logistic regression model was used to assess the association between hearing loss and postural instability. Data were analyzed from August 18, 2019, to September 2, 2019. Exposures: Age-related hearing loss defined as a threshold of 26 dB or more. Main Outcomes and Measures: The degree of hearing loss and postural instability. Results: Of the 3864 participants included in the study, the mean (SD) age was 57.8 (11.3) years and 2135 (55.2%) were women. Female sex was associated with higher odds of postural instability compared with male sex (odds ratio [OR], 1.65; 95% CI, 1.12-2.42, adjusted for age and hearing status), and the odds of postural instability increased with every 1 year increase in age (OR, 1.13; 95% CI, 1.10-1.16, adjusted for sex and hearing status). Unilateral or bilateral mild hearing loss was not associated with an increase in the odds of postural instability, but moderate hearing loss present on at least 1 side was associated with an increase in the odds of postural instability: unilateral moderate hearing loss group (OR, 2.71; 95% CI, 1.12-6.10, adjusted for age and sex), one mild and the other moderate hearing loss group (OR, 2.18; 95% CI, 1.16-4.09, adjusted for age and sex), and bilateral moderate hearing loss group (OR, 2.34; 95% CI, 1.27-4.33, adjusted for age and sex). Conclusions and Relevance: Aging, female sex, and having hearing loss were associated with postural instability in this analysis. Moderate or worse hearing loss present on at least 1 side was associated with increased odds of postural instability. Future research in this area is warranted to identify more precise interrelationships and preventive measures.

Postural instability according to virtual reality program.

Background: The popularity of virtual reality (VR) grew rapidly. Short guidelines with a lack of emphasis on safe use appears prior to usage. It is necessary for the user to realize how much potentially dangerous VR is. Aims/objectives: The aim of this study is to investigate the effect of VR on balance in normal people. Materials and methods: Mean equilibrium score (MES) of 15 adults who have normal sense of balance were obtained by using the sensory organization test (SOT). Conditions 1 and 2 were performed. Multiple VR programs were classified as three levels (Easy, Average, and Challenging) by the visual analog scale. Further SOT tests were performed during watching VR programs. MES of each test was used for statistical analysis. Results: MES of condition 1 was significantly higher than condition 2. Although there was no statistical difference between Eye open and Easy program (p = .097), MES of average and Challenging programs showed significantly decreased scores compared to Eye open. In addition, MES of Average and Challenging programs were significantly decreased than that of Easy program. Conclusions and significance: VR can cause postural imbalance to users. It is necessary to establish quantifiable and objective methods to measure imbalance caused by VR use.