New Formulas for Evaluation of Cyclohexanol Solidification on Substrates with Surface Nanostructures.

In semiconductor manufacturing, the sublimation drying process is crucial but poorly understood-particularly regarding the solidification of agents such as cyclohexanol on Si substrates. This knowledge gap results in inconsistent film properties and risks such as structural collapse. To address this critical gap in knowledge, the present study focused on an in-depth examination of the nucleation behavior exhibited by cyclohexanol during its cooling and solidification on Si substrates. Using a digital camera (GoPro10), the solidification process in experiments was recorded for a range of cooling rates and using substrates with distinct surface patterns. To evaluate temporal changes in crystal nucleation, video images were visually checked, and the temporal changes in the number of nuclei were examined. For a more quantitative analysis, the least-squares method was successfully employed to correlate mathematical equations to time-dependent nucleation data. Interestingly, the outcomes revealed significant correlations between the nucleation rate, cooling rate, and substrate pattern. In summary, this research offers a robust experimental framework for understanding the complex solidification behavior of cyclohexanol on Si substrates. The study contributes both qualitative and quantitative analyses, enriching our understanding of the variables that govern the solidification process, which has significant implications for enhancing the overall reliability and efficiency of semiconductor manufacturing.

Mesoporous hydrogel electrodes with flexible frameworks exhibiting enhanced mass transport for the oxygen evolution reaction.

Mesoporous hydrogel electrodes with unique flexible mesopores surrounded by CoOOH nanosheets were prepared via the electrochemical deposition of hybrid cobalt hydroxide nanosheets, exhibiting high oxygen evolution reaction activity at a high current density owing to the enhanced mass transport of oxygen molecules.

Kinetics formulation for Two-Dimensional Growth Behavior of Water/Ice Interface on Si Substrate.

Sublimation drying is used in the drying process of semiconductor device manufacturing. However, the solidification behavior mechanics of sublimation agents on substrates has not been clarified. Therefore, the properties of solidified films within substrate surfaces can become nonuniform, leading to their collapse. This study aimed to analyze the interface growth behavior during the cooling and solidification of a water/ice system as a basic case and to clarify the dynamic mechanism of the solidification behavior of liquid films on Si substrates. The solidification behavior of a water/ice system on Si substrates was captured on a video at different cooling rates. The recorded video was subjected to a digital image analysis to examine the crystal morphology and quantify the interface growth rate. The least-squares method with kinetic formulas was used to evaluate the feasibility of fitting the temperature variation to the interface growth rate. A visual examination of the morphology of interfacial growth revealed that it can be classified into four morphologies. The proposed kinetic equation describes the experimental results regarding the temperature dependence of the interfacial growth rate. Through image analysis, the interface growth rate of water and ice was quantified, and an evaluation formula was proposed.

Principles of Self-Repairing Ability of Tripodal Ligand-Stabilized Hybrid Cobalt Hydroxide Nanosheets for Alkaline Water Electrolysis.

Self-repairing catalysts are promising new materials for achieving long lifetime of alkaline water electrolyzers powered by renewable energy. Catalytic nanoparticles dispersed in an electrolyte were deposited on the anode to repair a catalyst layer by electrolysis. A hybrid cobalt hydroxide nanosheet modified with tris(hydroxymethyl)aminomethane on the surface (Co-ns) was used as a catalyst. Assuming a pseudo-first-order process, the rate constant of an electrochemical deposition was linearly correlated with the electrode potential during electrolysis. Thus, it is expected that the repair of the catalyst is automatically controlled by changes in the oxygen evolution reaction (OER) overpotential. The essential step of the electrochemical deposition was the anodic oxidation of Co2+ to Co3+ . Surface modification of Co-ns protects Co2+ against the autooxidation of Co2+ caused by the dissolved oxygen. The redox properties and organic modification of Co-ns make them well-suited for the self-repairing of anode catalysts.

Magnetization Precession at Sub-Terahertz Frequencies in Polycrystalline Cu2 Sb-Type (Mn-Cr)AlGe Ultrathin Films.

A ferromagnetic metal nanolayer with a large perpendicular magnetic anisotropy, small saturation magnetization, and small magnetic damping constant is a crucial requirement for high-speed spintronic devices. Fabrication of these devices on Si/SiO2 amorphous substrates with polycrystalline structure is also strongly desired for the mass production industry. This study involves the investigation of sub-terahertz (THz) magnetization precessional motion in a newly developed material system consisting of Cu2 Sb-type MnAlGe and (Mn-Cr)AlGe films by means of an all-optical pump-probe method. These materials exhibit large perpendicular magnetic anisotropy in regions of a few nanometers in size. The pseudo-2D crystal structures are clearly observed in the high-resolution transmission electron microscopy (TEM) images for the film samples grown on thermally oxidized silicon substrates. The TEM images also show a partial substitution of Cr atoms for the Mn sites in MnAlGe. A magnetization precession frequency of 0.164 THz with a relatively small effective magnetic damping constant of 0.012 is obtained for (Mn-Cr)AlGe. Theoretical calculation infers that the modification of the total density of states by Cr substitution decreases the intrinsic magnetic damping constant of (Mn-Cr)AlGe.

Degradation and inactivation efficacy of ozone water for antineoplastic drugs in hospital settings.

PURPOSE: Occupational exposure to antineoplastic drugs in hospital settings is recognized to be hazardous, and as such environmental decontamination including degradation and inactivation of such drugs is recommended. To data, although various agents such as oxidants have been reported to be useful for decontamination, simpler, safer, and more convenient methods are required. In this study, the degradation and inactivation efficacy of ozone water, which has newly been introduced for decontamination of antineoplastic drugs in spills, was investigated for formulations of gemcitabine, irinotecan, and paclitaxel. METHODS: Antineoplastic formulations (medicinal ingredient: ∼1.5 µmol) were mixed with 50 mL of ozone water (>4 mg/L). The reactions were monitored by high-performance liquid chromatography, and the degradation mixtures were analyzed by 1H nuclear magnetic resonance spectroscopy in order to obtain the structural information of the degradation products. The formulations of gemcitabine and irinotecan and those degradation mixtures were evaluated for their mutagenicity using the Ames test and cytotoxicity against human cancer cells. RESULTS: gemcitabine and irinotecan were found to be readily degraded by the ozone treatment, and their active sites were suggested to be degraded. In contrast, paclitaxel was hard to be decomposed, possibly owing to the consumption of ozone by the polyoxyethylene castor oil added as a pharmaceutical additive of the formulation. No significant mutagenic changes of Salmonella typhimurium strains used for the Ames test were observed for the samples within the concentration ranges examined. The ozone treatment showed obvious increases in cell viability for gemcitabine formulation, and mild increases for irinotecan formulation. CONCLUSIONS: Ozone water was shown to be effective as a decomposition agent for the antineoplastic drug formulations examined, although the efficacy depends on the chemical structures of the drugs and the pharmaceutical additives. It was also suggested that ozone treatment has a tendency to decrease the toxicity of the antineoplastic drug formulations. As such, further studies are required in order to clarify the effects and application limitations of ozone water.

A growing aneurysm of the posterior inferior cerebellar artery complicated with cerebellar infarction: A case report.

INTRODUCTION AND IMPORTANCE: Hereby we describe an instructive patient with cerebellar infarction and a growing aneurysm at the posterior inferior cerebellar artery (PICA), which was not a true cause of infarction. CASE PRESENTATION: A 50-year-old female presented with dizziness and posterior neck pain at our hospital (Mitaka city, Tokyo, Japan). Diffusion weighted magnetic resonance (MR) images showed cerebellar infarction in the left PICA territory and MR angiography study showed an aneurysm at the origin of the left PICA, which grew in 2 weeks. Since we considered cerebellar infarction was caused by thrombosis from the aneurysm, trapping of the PICA and occipital artery-PICA bypass was performed to prevent recurrent cerebellar infarction and rupture of the aneurysm by neurosurgeons. During the operation, dissection was observed at the distal PICA, which was diagnosed to be the true cause of cerebellar infarction. By the follow-up for 12 months at an outpatient, there was no recurrence of cerebral infarction. CLINICAL DISCUSSION: A specimen of the artery showing the findings of dissection was not obtained, and the pathological diagnosis could not be made. It would be controversial whether a surgical procedure presented here was the most optimal. CONCLUSION: This is a first reported case of growing aneurysms and cerebral infarction due to arterial dissection. Even if cerebral infarction is accompanied by growing aneurysms, arterial dissection should be included in the differential diagnoses of a cause of infarction. Posterior cervical pain can be a clue for early appropriate diagnosis in such a case.

Alkali and Alkaline Earth Metal Ions Complexes with a Partial Peptide of the Selectivity Filter in K+ Channels Studied by a Cold Ion Trap Infrared Spectroscopy.

The front cover artwork is provided by Takashi Tsujino (Science Graphics Co., Ltd.) . The image shows the efficacy of a bottom-up approach to ion selectivity of K+ channels. The GYG-K+ complex, which replicates the local portion of K+ channels, has three conformations with an equivalent distribution. Read the full text of the Article at 10.1002/cphc.202000033.

Alkali and Alkaline Earth Metal Ions Complexes with a Partial Peptide of the Selectivity Filter in K+ Channels Studied by a Cold Ion Trap Infrared Spectroscopy.

The infrared (IR) spectra of alkali and alkaline earth metal ion complexes with the Ac-Tyr-NHMe (GYG) peptide have been measured by laser photodissociation in a cold ion trap coupled with an electrospray mass spectrometer. The GYG peptide corresponds to a portion of the ion selectivity filter in the KcsA K+ channel that allows K+ to pass, but blocks Na+ even though it has a smaller ionic radius than K+ . This current study extends a previous investigation on Na+ and K+ to the entire set of alkali metaI ions and alkaline earth dications. IR-IR hole-burning (IR2 dip) spectroscopy has established the coexistence of several conformers of the GYG-metal ion complexes. The structures of the conformers were assigned by comparison between the isomer-selected IR spectra and theoretical IR spectra obtained from quantum chemical calculations. It was found that the structure of the dominant conformer correlates with the ability of the ion to permeate through the K+ channel.

Ion-peptide interactions between alkali metal ions and a termini-protected dipeptide: modeling a portion of the selectivity filter in K+ channels.

Potassium channels have the unique ability to allow the selective passage of potassium ions at near diffusion-free rates while inhibiting the passage of more abundant sodium ions. Local interactions between chemical functional groups and the ions are responsible for both selectivity and transport. As an initial step in characterizing these interactions, the structures of Na+ and K+ complexed to the Ac-Tyr-NHMe peptide have been determined from infrared laser spectroscopy and supporting ab initio calculations. Ac-Tyr-NHMe, a termini-protected peptide sequence, replicates the GYG portion of one of the four peptide chains comprising the selectivity filter of a K+ channel. This peptide contains two carbonyl groups, among the eight C[double bond, length as m-dash]O groups forming the S1 binding site of the selectivity filter. Three conformations have been identified for both ions by laser IR-IR double resonance methods. Two conformations have the ion bound to the two C[double bond, length as m-dash]O groups. The third conformation has, in addition, a cation-π interaction with the aromatic ring of tyrosine, i.e. tridentate binding. The relative contributions of the three conformers are approximately the same for K+Ac-Tyr-NHMe, while the tridentate conformer is preferred for Na+Ac-Tyr-NHMe. These differences will be discussed in the context of ion mobility and selectivity.

Modulation of magnetization dynamics in an epitaxial Heusler ferromagnet due to pure spin current in a laterally configured structure.

Using a laterally configured structure, we demonstrate modulation of the magnetization dynamics of an epitaxial Heusler ferromagnet, Fe3Si, by nonlocally injecting pure spin currents. From the ferromagnetic resonance signals, the effective Gilbert damping constant ([Formula: see text]) of the epitaxial Fe3Si nanomagnet is estimated to be ∼0.003 at room temperature. By using the lateral and nonlocal spin injection, the [Formula: see text] value of the epitaxial Fe3Si nanomagnet can be modulated from 0.0034 to 0.0024. This study will open a way for control of the magnetization dynamics of high-performance ferromagnetic Heusler alloys due to pure spin currents even in laterally configured structures.

Ultraviolet optical vortex generation using a pair of ß-BaB2O4 crystals with inverted orientations.

Picosecond pulsed frequency-doubled optical vortices were generated using a pair of ß-BaB2O4 crystals with their c axes inverted. This arrangement produced high-quality ultraviolet vortex output with low spatial separation of the phase singularity at a conversion efficiency of ∼40%. We also discuss the theoretical spatial form and beam propagation of the ultraviolet vortex output.

Fructo-oligosaccharide-Induced Transient Increases in Cecal Immunoglobulin A Concentrations in Rats Are Associated with Mucosal Inflammation in Response to Increased Gut Permeability.

Background: The mechanism underlying transient increases in immunoglobulin (Ig) A concentrations in the cecal contents of rats fed fructo-oligosaccharide (FOS) is unclear.Objective: This study was designed to test whether increased IgA concentrations represent one aspect of the inflammatory response to increased permeability induced by FOS in the cecum.Methods: Seven-week-old male Wistar rats were fed a fiber-free semipurified diet (FFP) with or without supplemental FOS (60 g/kg diet) for 9 or 58 d [experiment (expt.) 1], 7 d (expt. 2), or 7 or 56 d (expt. 3). In addition to measuring IgA concentrations in cecal content, we assessed gut permeability, inflammatory responses (expt. 1), the number of IgA plasma cells in the cecal lamina propria, polymeric Ig receptor (pIgR) expression in the cecal mucosa (expt. 2), and the condition of the cecal mucus layer (expt. 3).Results: The cecal IgA concentration in the FOS-fed rats was 15-fold higher than that of the rats fed FFP for 9 d (P < 0.05). Gut permeability estimated by urinary chromium-EDTA excretion, bacterial translocation to mesenteric lymph nodes, myeloperoxidase activity, and expression of inflammatory cytokine genes in the cecal mucosa was greater in the FOS-fed rats than in the rats fed FFP for 9 d. These effects were not observed in the rats fed FOS for 58 d (expt. 1). Accompanying the higher cecal IgA concentration, pIgR protein and the number of IgA plasma cells in the cecal mucosa were higher in the FOS-fed rats than in the rats fed FFP for 7 d (expt. 2). Destruction of the mucus layer on the epithelial surface, as evidenced by Alcian blue staining in the cecal sections, was evident in the rats fed FOS for 7 d, but the mucus layer appeared normal in the rats fed FOS for 56 d (expt. 3).Conclusions: These findings suggest that transient increases in cecal IgA concentrations induced by FOS in rats are associated with mucosal inflammation in response to increased gut permeability; these are presumably evoked by disruption of the cecal mucus barrier. The observed responses could contribute to the maturation of the gut immune system.

Highly intense monocycle terahertz vortex generation by utilizing a Tsurupica spiral phase plate.

Optical vortex, possessing an annular intensity profile and an orbital angular momentum (characterized by an integer termed a topological charge) associated with a helical wavefront, has attracted great attention for diverse applications due to its unique properties. In particular for terahertz (THz) frequency range, several approaches for THz vortex generation, including molded phase plates consisting of metal slit antennas, achromatic polarization elements and binary-diffractive optical elements, have been recently proposed, however, they are typically designed for a specific frequency. Here, we demonstrate highly intense broadband monocycle vortex generation near 0.6 THz by utilizing a polymeric Tsurupica spiral phase plate in combination with tilted-pulse-front optical rectification in a prism-cut LiNbO3 crystal. A maximum peak power of 2.3 MW was obtained for THz vortex output with an expected topological charge of 1.15. Furthermore, we applied the highly intense THz vortex beam for studying unique nonlinear behaviors in bilayer graphene towards the development of nonlinear super-resolution THz microscopy and imaging system.

Beam propagation of efficient frequency-doubled optical vortices.

Frequency doubling of optical vortices is demonstrated with an optical-optical efficiency exceeding 70%, using a spiral phase plate at a fundamental vortex energy of 10.6 mJ. Beam propagation of the doubled vortex output is also investigated both experimentally and theoretically. Spatial transforms in the output during propagation are observed.

Hydrogen Peroxide-Induced Oxidative Stress Activates Proteasomal Trypsin-Like Activity in Human U373 Glioma Cells.

Degradation of oxidized or oxidatively modified proteins is an essential part of the cellular antioxidant defense system. 4-Hydroxy-2-nonenal, a major reactive aldehyde formed by lipid peroxidation, causes many types of cellular damage. The major proteolytic system for modified protein degradation is the ubiquitin-proteasome pathway. However, our previous studies using U937 human leukemic cells showed that 4-hydroxy-2-nonenal-modified glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is degraded by cathepsin G. In the present study, U373 human glioma cells were cultured in the presence of hydrogen peroxide (H2O2) to investigate the relationships of proteasome and/or cathepsin G activities and H2O2-induced GAPDH degradation. Treatment of cells with H2O2 for 5 h in culture decreased GAPDH activity as well as its protein concentration in a concentration-dependent manner. Two proteasomal activities (peptidylglutamyl-peptide hydrolase and chymotrypsin-like hydrolase activities) and cathepsin G activity were decreased by H2O2 treatment in a concentration-dependent manner, but proteasomal trypsin-like hydrolase activity increased with cell exposure to high H2O2 concentrations. Among the protease inhibitors examined here, H2O2-induced activation of trypsin-like activity and GAPDH degradation were inhibited by the proteasome inhibitor lactacystin. Furthermore, H2O2-induced activation of trypsin-like activity was also inhibited by another proteasome inhibitor MG-132. These results suggested that proteasomal trypsin-like activity played an important role in eliminating oxidatively modified GAPDH formed in these cells during H2O2 exposure.

Ultraviolet vortex generation using periodically bonded ß-BaB2O4 device.

This paper describes the first demonstration of ultraviolet (266nm) vortex generation using the combination of a frequency-doubled nanosecond green laser, a spiral phase plate, and a periodically bonded ß-BaB2O4 device. For a laser pumping energy of 9.1 mJ, an ultraviolet vortex energy of 1.24 mJ was obtained, corresponding to a conversion efficiency of 13.7%.