Driving frequency dependency of gas species in the bubble formation for aqua-plasma generation

Effects of voltage driving frequency on the gas composition, electrical and optical emission properties of aqua-plasmas generated in electrolyte solution, are investigated and the experiment was carried out in the range of 10 Hz–50 kHz. In the range of 10–300 Hz, H₂ dominated bubbles are generated and it is attributed to electrolysis. With increasing frequency, the gas composition inside the bubble changes to the H₂O which can be determined from the observation of atomic H to OH(A-X) transition from the optical measurements of aqua-plasma. In higher frequency than 2 kHz, the boiling on the electrode dominates to the formation of the bubble. Consequently, the radicals and plasma properties are varied with the driving frequency.     

Transfer of functional memory devices to any substrate

Electronic devices on unconventional substrates are attractive beyond the conventional solid‐state rigid electronic system or even flexible electronics. Here, by use of the transfer printing technique, we report the memory devices onto a range of unconventional substrates, including paper, an insect (cicada), glass, polyethersulphone, polyimide, double‐sided tape, Al foil, fabric, a mask, a leather wallet, a name card, a banknote, a latex glove, and a squeezed plastic bottle. The device can be possibly realized on any substrate. The memory structure used in this work is non‐volatile resistive random access memory (RRAM). Constraints imposed by process compatibility between the substrates and device materials are completely eliminated by the use of the transfer printing techniques. It is confirmed that the electrical characteristics of the RRAM devices do not degrade during the transfer process. Stable resistive switching properties, reliable endurance levels, and good retention characteristics are demonstrated. The mechanical stability is also analysed and an encapsulation protection layer on top of the memory devices is suggested for long‐term reliability. The possibility of the realization of integrated electronic systems onto various substrates will enable the versatile use of these electronics anywhere and anytime in many different environments.

     

Moderate deviations for marked Hawkes processes

We consider a linear Hawkes process with random marks. Some limit theorems have been studied by Karabash and Zhu [Stoch. Models, 31, 433–451 (2015)]. In this paper, we obtain a moderate deviation principle for marked Hawkes processes.     

The impact of information technology on organizational efficiency in public services: a DEA-based DT approach

This study attempts to examine the impact of information technology (IT) on organizational efficiency in public services. We propose a new approach to providing the directions of IT investments to improve organizational efficiency. The proposed approach is based on the integrated form of data envelopment analysis (DEA) and decision tree (DT), and composed of two steps. First, DEA is conducted to measure organizational efficiency with the selected inputs and outputs. Second, DT is built based on efficiency scores obtained from DEA and IT factors, as a target variable and predictor variables, respectively. In doing so, we can identify the relative impact of IT investments on organizational efficiency and set priorities to the IT investments to improve efficiency from a view point of each organization. A case study on the Korean local governments is presented to illustrate the usefulness of the proposed approach.     

Organic glass-forming materials: 1,3,5-tris(naphthyl)benzene derivatives

The organic glass-forming materials 1,3-bis(1-naphthyl)-5-(2-naphthyl)benzene (2) and its partially deuterated analogue, 1,3-bis(1-naphthyl-d(7))-5-(2-naphthyl)benzene (2-d(14)), have been synthesized on a gram scale using Suzuki coupling reactions. Detailed spectroscopic studies afford complete NMR assignments (1H, 2H, 13C) for both compounds. Modest energy barriers for the interconversion of atropisomers (ca. 15 kcal/mol) result in a propensity for these materials to form supercooled liquids and glasses, rather than undergoing crystallization. The preparation of these materials enables detailed studies of physical properties of organic glasses and molecular diffusion in condensed phases.     

Bisphosphonate enhances TRAIL sensitivity to human osteosarcoma cells via death receptor 5 upregulation

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), a member of the TNF superfamily of cytokines, is one of the most promising candidates for cancer therapeutics. However, many osteosarcomas are resistant to TRAIL. Bisphosphonates are very effective in the treatment of bone problems associated with malignancies; the antitumor effects are due to the inhibition of protein prenylation that is essential for cell function and survival. The purpose of this study was to determine the effects of bisphosphonates on TRAIL-resistant MG 63 human osteosarcoma cells. The cells showed no response to TRAIL alone; however, pre-treatment with bisphosphonates significantly increased TRAIL-mediated apoptosis and cellular activation of caspase-3. Bisphosphonates significantly induced mRNA and protein expression of the TRAIL receptor, DR5. Bisphosphonates induced protein unprenylation in MG 63 cells; in addition, co-treatment with TRAIL also significantly increased protein unprenylation. Blocking of protein unprenylation using geranylgeraniol attenuated the cellular responses, including cell apoptosis and protein unprenylation induced by bisphosphonates and TRAIL. This is the first study to demonstrate that bisphosphonates markedly enhanced TRAIL-induced apoptosis in human osteosarcoma cells. These findings suggest that bisphosphonates may be a new and effective anticancer treatment with TRAIL proteins for TRAIL-resistant cancer cells.     

Infrared spectrum of matrix isolated selenoformaldehyde, CH2Se, and CD2Se

Thermolysis of highly diluted (CH2Se)3 or (CD2Se)3 in a flow of argon with subsequent quenching of the products in an matrix at 15 K yields monomeric CH2Se and CD2Se, respectively. Six fundamental vibrations upsilon1 = 2972.5, upsilon2 = 1413.3, upsilon3 = 854.2, upsilon4 = 916.4, upsilon 5 = 3052.9, and upsilon 6 = 913.2 cm(-1) and two combination bands have been observed for CH2Se as well as three fundamentals of CD2Se. The vibrational wavenumbers are compared with those of CH2O and CH2S. Matrix isolated selenoformaldehyde decomposes slowly by UV photolysis to yield the CSe molecule.     

Decreased expression of DNA repair proteins Ku70 and Mre11 is associated with aging and may contribute to the cellular senescence

The gradual loss of telomeric DNA can contribute to replicative senescence and thus, having longer telomeric DNA is generally considered to provide a longer lifespan. Maintenance and stabilization of telomeric DNA is assisted by binding of multiple DNA-binding proteins, including those involved in double strand break (DSB) repair. We reasoned that declining DSB repair capacity and increased telomere shortening in aged individuals may be associated with decreased expression of DSB repair proteins capable of telomere binding. Our data presented here show that among the DSB repair proteins tested, only the expression of Ku70 and Mre11 showed statistically significant age-dependent changes in human lymphocytes. Furthermore, we found that expressions of Ku70 and Mre11 are statistically correlated, which indicate that the function of Ku70 and Mre11 may be related. All the other DSB repair proteins tested, Sir2, TRF1 and Ku80, did not show any significant differences upon aging. In line with these data, people who live in the regional community (longevity group), which was found to have statistically longer average life span than the rest area, shows higher level of Ku70 expression than those living in the neighboring control community. Taken together, our data show, for the first time, that Ku70 and Mre11 may represent new biomarkers for aging and further suggest that maintenance of higher expression of Ku70 and Mre11 may be responsible for keeping longer life span observed in the longevity group.     

Composite thermal conductivity in a large heterogeneous porous methane hydrate sample

By employing inverse modeling to analyze the laboratory data, we determined the composite thermal conductivity (k(theta), W/m/K) of a porous methane hydrate sample ranged between 0.25 and 0.58 W/m/K as a function of density. The calculated composite thermal diffusivities of porous hydrate sample ranged between 2.59 x 10(-7) m(2)/s and 3.71 x 10(-7) m(2)/s. The laboratory study involved a large heterogeneous sample (composed of hydrate, water, and methane gas). The measurements were conducted isobarically at 4.98 MPa over a temperature range of 277.3-279.1 K. Pressure and temperature were monitored at multiple locations in the sample. X-ray computed tomography (CT) was used to visualize and quantify the density changes that occurred during hydrate formation from granular ice. CT images showed that methane hydrate formed from granular ice was heterogeneous and provided an estimate of the sample density variation in the radial direction. This facilitated quantifying the density effect on composite thermal conductivity. This study showed that the sample heterogeneity should be considered in thermal conductivity measurements of hydrate systems. Mixing models (i.e., arithmetic, harmonic, geometric mean, and square root models) were compared to the estimated composite thermal conductivity determined by inverse modeling. The results of the arithmetic mean model showed the best agreement with the estimated composite thermal conductivity.