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This study examined the local structural properties of Pt nanoparticles on SiO, TiO-SiO, and ZrO-SiO supports to better understand the impact of oxide-support type on the performance of Pt-based catalysts. In situ X-ray absorption fine structure (XAFS) measurements were taken for the Pt L-edge in a temperature range from 300 to 700 K in He, H, and O gas environments. The XAFS measurements demonstrated that Pt atoms were highly dispersed on TiO-SiO and ZrO-SiO forming pancake-shaped nanoparticles, whereas Pt atoms formed larger particles of hemispherical shapes on SiO supports. Contrary to the SiO case, the coordination numbers for Pt, Ti, and Zr around Pt atoms on the TiO-SiO and ZrO-SiO supports were nearly constant from 300 to 700 K under the different gas environments. These results are consistent with the improvements in thermal stability of Pt nanoparticles achieved by incorporating TiO or ZrO on the surface of SiO supports. XAFS analysis further indicated that the enhanced dispersion and stability of Pt were a consequence of the strong metal support interaction via Pt-Ti and Pt-Zr bonds. Graphical Abstract: From XANES measurements, oxygen coordination numbers of a Pt atom on different supports of (a) SiO, (b) TiO-SiO, and (c) ZrO-SiO were determined. As temperature increases, oxygen coordination numbers gradually decreased in a He gas, whereas it is dramatically decreases in an H gas.[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a potentially useful anticancer agent with exquisite selectivity for cancer cells. Unfortunately, many cancers show or acquire resistance to TRAIL. In this study we report that TRAIL activates a TGF-β-activated kinase 1 → mitogen-activated protein kinase (MAPK) kinase 3 (MKK3)/MKK6 → p38 pathway in prostate cancer cells that transcriptionally upregulates expression of the antiapoptotic BCL-2 family member MCL-1. TRAIL alone triggered robust formation of the ‘death-inducing signaling complex’ (DISC), activation of the initiator caspase-8, and truncation of the BH3-only protein BID (tBID). Nevertheless, simultaneous disruption of the p38 MAPK pathway was required to suppress MCL-1 expression, thereby allowing tBID to activate the proapoptotic BCL-2 family member BAK and stimulate mitochondrial outer membrane permeabilization (MOMP). Release of the inhibitor-of-apoptosis (IAP) antagonist, Smac/DIABLO, from the intermembrane space was sufficient to promote TRAIL-induced apoptosis, whereas release of cytochrome c and activation of the apoptosome was dispensable. Even after MOMP, however, mitochondrial-generated reactive oxygen species (ROS) activated a secondary signaling pathway, involving c-Jun N-terminal kinases (JNKs), that similarly upregulated MCL-1 expression and partially rescued some cells from death. Thus, stress kinases activated at distinct steps, before and after mitochondrial injury, mediate TRAIL resistance through maintenance of MCL-1 expression. [ABSTRACT FROM AUTHOR]

The article cites a study conducted to determine concentrations, distribution and sources of polycyclic aromatic hydrocarbons (PAHs) in Saemangeum reclaimed tidal lands of western seacoast, Korea, which is currently under construction. Levels of PAHs in the reclaimed tidal lands can help the environmental risk assessment of those areas in many ways. Researchers stated that PAH with three and more rings tend to be strongly adsorbed to the soil. Strong sorption coupled with very low water solubility and very low vapor pressures make leaching and volatilization insignificant pathway of PAH dissipation.

The annual modulation signal observed by the DAMA experiment is a long-standing question in the community of dark matter direct detection. This necessitates an independent verification of its existence using the same detection technique. The COSINE-100 experiment has been operating with 106 kg of low-background NaI(Tl) detectors providing interesting checks on the DAMA signal. However, due to higher backgrounds in the NaI(Tl) crystals used in COSINE-100 relative to those used for DAMA, it was difficult to reach final conclusions. Since the start of COSINE-100 data taking in 2016, we also have initiated a program to develop ultra-pure NaI(Tl) crystals for COSINE-200, the next phase of the experiment. The program includes efforts of raw powder purification, ultra-pure NaI(Tl) crystal growth, and detector assembly techniques. After extensive research and development of NaI(Tl) crystal growth, we have successfully grown a few small-size (0.61–0.78 kg) thallium-doped crystals with high radio-purity. A high light yield has been achieved by improvements of our detector assembly technique. Here we report the ultra-pure NaI(Tl) detector developments at the Institute for Basic Science, Korea. The technique developed here will be applied to the production of NaI(Tl) detectors for the COSINE-200 experiment. [ABSTRACT FROM AUTHOR]