Photothermally carbonized natural kelp for hydrovoltaic power generation.

We have developed an eco-friendly and efficient method for hydrovoltaic power generation through carbonizing natural kelp, a hydrogel with abundant cations. Under ambient conditions, a CO2 laser beam was focused on the top surface of dried kelp, photothermally converting it into porous graphitic carbon (PGC) and reducing dissociable cations by thermal evaporation. Owing to the preservation of the bottom surface, this photothermal process yielded a PGC-hydrogel membrane (PHM) featuring a cation concentration gradient. With the introduction of deionized water to the intact region, the kelp hydrogel retained a considerable volume of water, creating a moist environment for the PGC. The cation concentration gradient facilitated a continuous migration of cations between the PGC and unaltered kelp, generating a voltage of 0.34 V and a current density of 49 µA/cm2. We demonstrated its practical applicability by turning on three light-emitting diodes using an array of eight PHMs.

Energy-Based Unified Models for Predicting the Fatigue Life Behaviors of Austenitic Steels and Welded Joints in Ultra-Supercritical Power Plants.

The development of a cost-effective and accurate model for predicting the fatigue life of materials is essential for designing thermal power plants and assessing their structural reliability under operational conditions. This paper reports a novel energy-based approach for developing unified models that predict the fatigue life of boiler tube materials in ultra-supercritical (USC) power plants. The proposed method combines the Masing behavior with a cyclic stress-strain relationship and existing stress-based or strain-based fatigue life prediction models. Notably, the developed models conform to the structure of the modified Morrow model, which incorporates material toughness (a temperature compensation parameter) into the Morrow model to account for the effects of temperature. A significant advantage of this approach is that it eliminates the need for tensile tests, which are otherwise essential for assessing material toughness in the modified Morrow model. Instead, all material constants in our models are derived solely from fatigue test results. We validate our models using fatigue data from three promising USC boiler tube materials-Super304H, TP310HCbN, and TP347H-and their welded joints at operating temperatures of 500, 600, and 700 °C. The results demonstrate that approximately 91% of the fatigue data for all six materials fall within a 2.5× scatter band of the model's predictions, indicating a high level of accuracy and broad applicability across various USC boiler tube materials and their welded joints, which is equivalent to the performance of the modified Morrow model.

Enhancing Si3N4 Selectivity over SiO2 in Low-RF Power NF3-O2 Reactive Ion Etching: The Effect of NO Surface Reaction.

Highly selective etching of silicon nitride (Si3N4) and silicon dioxide (SiO2) has received considerable attention from the semiconductor community owing to its precise patterning and cost efficiency. We investigated the etching selectivity of Si3N4 and SiO2 in an NF3/O2 radio-frequency glow discharge. The etch rate linearly depended on the source and bias powers, whereas the etch selectivity was affected by the power and ratio of the gas mixture. We found that the selectivity can be controlled by lowering the power with a suitable gas ratio, which affects the surface reaction during the etching process. X-ray photoelectron spectroscopy of the Si3N4 and QMS measurements support the effect of surface reaction on the selectivity change by surface oxidation and nitrogen reduction with the increasing flow of O2. We suggest that the creation of SiOxNy bonds on the surface by NO oxidation is the key mechanism to change the etch selectivity of Si3N4 over SiO2.

Development of the Tele-Measurement of Plasma Uniformity via Surface Wave Information (TUSI) Probe for Non-Invasive In-Situ Monitoring of Electron Density Uniformity in Plasma Display Fabrication Process.

The importance of monitoring the electron density uniformity of plasma has attracted significant attention in material processing, with the goal of improving production yield. This paper presents a non-invasive microwave probe for in-situ monitoring electron density uniformity, called the Tele-measurement of plasma Uniformity via Surface wave Information (TUSI) probe. The TUSI probe consists of eight non-invasive antennae and each antenna estimates electron density above the antenna by measuring the surface wave resonance frequency in a reflection microwave frequency spectrum (S11). The estimated densities provide electron density uniformity. For demonstration, we compared it with the precise microwave probe and results revealed that the TUSI probe can monitor plasma uniformity. Furthermore, we demonstrated the operation of the TUSI probe beneath a quartz or wafer. In conclusion, the demonstration results indicated that the TUSI probe can be used as an instrument for a non-invasive in-situ method for measuring electron density uniformity.

Observation of prior light emission before arcing development in a low-temperature plasma with multiple snapshot analysis.

Arcing is a ubiquitous phenomenon and a crucial issue in high-voltage applied systems, especially low-temperature plasma (LTP) engineering. Although arcing in LTPs has attracted interest due to the severe damage it can cause, its underlying mechanism has yet to be fully understood. To elucidate the arcing mechanism, this study investigated various signals conventionally used to analyze arcing such as light emission, arcing current and voltage, and background plasma potential. As a result, we found that light emission occurs as early as 0.56 µs before arcing current initiation, which is a significant indicator of the explosive development of arcing as well as other signals. We introduce an arcing inducing probe (AIP) designed to localize arcing on the tip edge along with multiple snapshot analysis since arcing occurs randomly in space and time. Analysis reveals that the prior light emission consists of sheath and tip glows from the whole AIP sheath and the AIP tip edge, respectively. Formation mechanisms of these emissions based on multiple snapshot image analysis are discussed. This light emission before arcing current initiation provides a significant clue to understanding the arcing formation mechanism and represents a new indicator for forecasting arcing in LTPs.

Head and Neck Cancer Cell Death due to Mitochondrial Damage Induced by Reactive Oxygen Species from Nonthermal Plasma-Activated Media: Based on Transcriptomic Analysis.

Mitochondrial targeted therapy is a next-generation therapeutic approach for cancer that is refractory to conventional treatments. Mitochondrial damage caused by the excessive accumulation of reactive oxygen species (ROS) is a principle of mitochondrial targeted therapy. ROS in nonthermal plasma-activated media (NTPAM) are known to mediate anticancer effects in various cancers including head and neck cancer (HNC). However, the signaling mechanism of HNC cell death via NTPAM-induced ROS has not been fully elucidated. This study evaluated the anticancer effects of NTPAM in HNC and investigated the mechanism using transcriptomic analysis. The viability of HNC cells decreased after NTPAM treatment due to enhanced apoptosis. A human fibroblast cell line and three HNC cell lines were profiled by RNA sequencing. In total, 1 610 differentially expressed genes were identified. Pathway analysis showed that activating transcription factor 4 (ATF4) and C/EBP homologous protein (CHOP) were upstream regulators. Mitochondrial damage was induced by NTPAM, which was associated with enhancements of mitochondrial ROS (mtROS) and ATF4/CHOP regulation. These results suggest that NTPAM induces HNC cell death through the upregulation of ATF4/CHOP activity by damaging mitochondria via excessive mtROS accumulation, similar to mitochondrial targeted therapy.

EGR1/GADD45α Activation by ROS of Non-Thermal Plasma Mediates Cell Death in Thyroid Carcinoma.

(1) Background: Nonthermal plasma (NTP) induces cell death in various types of cancer cells, providing a promising alternative treatment strategy. Although recent studies have identified new mechanisms of NTP in several cancers, the molecular mechanisms underlying its therapeutic effect on thyroid cancer (THCA) have not been elucidated. (2) Methods: To investigate the mechanism of NTP-induced cell death, THCA cell lines were treated with NTP-activated medium -(NTPAM), and gene expression profiles were evaluated using RNA sequencing. (3) Results: NTPAM upregulated the gene expression of early growth response 1 (EGR1). NTPAM-induced THCA cell death was enhanced by EGR1 overexpression, whereas EGR1 small interfering RNA had the opposite effect. NTPAM-derived reactive oxygen species (ROS) affected EGR1 expression and apoptotic cell death in THCA. NTPAM also induced the gene expression of growth arrest and regulation of DNA damage-inducible 45α (GADD45A) gene, and EGR1 regulated GADD45A through direct binding to its promoter. In xenograft in vivo tumor models, NTPAM inhibited tumor progression of THCA by increasing EGR1 levels. (4) Conclusions: Our findings suggest that NTPAM induces apoptotic cell death in THCA through a novel mechanism by which NTPAM-induced ROS activates EGR1/GADD45α signaling. Furthermore, our data provide evidence that the regulation of the EGR1/GADD45α axis can be a novel strategy for the treatment of THCA.

Short-term effect of a smartphone application on the mental health of university students: A pilot study using a user-centered design self-monitoring application for mental health.

BACKGROUND: Despite the widespread recognition of the importance of mental health in young people, only a small proportion of young people with a mental disorder, including university students, receive mental health care. OBJECTIVE: We developed a smartphone application (Mental App) for the university students and examined the effects of the app on their mental health. METHODS: The app was designed according to a questionnaire survey conducted before this study. The Mental App was installed on the students' smartphone and the psychological tests (the Link Stigma Scale, the Center for Epidemiologic Studies Depression Scale, and the 12-item General Health Questionnaire) were performed on the same day. After using the App for two weeks, the students completed a questionnaire survey and underwent the same psychological tests. We compared the results between the app user and non-user group. RESULTS: A total of 68 students participated, of which 57 students completed the study (app user group, n = 28; control group, n = 29). The mean number of days spent using the app was 5.66 ± 3.16 (mean ± SD). The mean total screen time of the app was 9:03 ± 06:41(min:sec). The mean number of total actions (screen taps or swipes) was 161.91 ± 107.34. There were no significant between-group differences in the ΔLink Stigma Scale score (-0.11 ± 4.28 vs. -0.59 ± 3.30, p = 0.496) or the ΔCenter for Epidemiologic Studies Depression Scale score (-4.39 ± 7.13 vs. -2.07 ± 8.78, p = 0.143). There was a significant between-group difference in the ΔGeneral Health Questionnaire score (-2.21± 2.23 vs. -0.17 ± 2.69, p = 0.007). CONCLUSIONS: This non-randomized controlled pilot study indicates that the app we developed, may provide effective mental health care for university students, even in the short-term. Trial registration: UMIN000040332.

Crystal structure of {2-methyl-2-[(pyridin-2-yl-meth-yl)amino]-propan-1-ol-κ3 N,N',O}bis-(nitrato-κO)copper(II) from synchrotron data.

The title compound, [Cu(NO3)2(C10H16N2O)], has been synthesized and characterized by synchrotron single-crystal diffraction at 100 K. The CuII ion has a distorted square-pyramidal coordination geometry with two N and one O atoms of the C10H16N2O ligand and one nitrate anion in the equatorial plane and another nitrate anion at the axial position. The equatorial Cu-N and Cu-O bond lengths are in the range 1.9608 (14)-2.0861 (15) Å, which are shorter than the axial Cu-Onitrate bond length [2.1259 (16) Å]. In the crystal, mol-ecules are linked via inter-molecular N-H⋯O and O-H⋯O hydrogen bonds, forming a sheet structure parallel to the bc plane. The sheets are further linked through a face-to-face π-π inter-action [centroid-centroid distance = 3.994 (1) Å]. Weak inter-molecular C-H⋯O inter-actions are also observed in the sheet and between adjacent sheets.

Crystal structure of di-chlorido-{2-methyl-2-[(pyridin-2-ylmeth-yl)amino]-propan-1-ol-κ3N,N',O}copper(II) from synchrotron data.

The title compound, [CuCl2(C10H16N2O)], has been synthesized and characterized by synchrotron single-crystal X-ray diffraction and FT-IR spectroscopy. The 2-methyl-2-[(pyridin-2-ylmeth-yl)amino]-propan-1-ol (mpmapOH) ligand, including pyridine, amine and hy-droxy groups, was synthesized by the reaction of 2-amino-2-methyl-propan-1-ol with pyridine-2-carbaldehyde and was characterized by NMR spectroscopy. In its CuII complex, the metal ion has a distorted square-pyramidal coordination geometry with two N and one O atom of the mpmapOH ligand and one chloride anion in the equatorial plane, and the second chloride in an axial position. The bond lengths involving the CuII ion range from 1.9881 (10) to 2.0409 (9) for the Cu-N and Cu-O bonds, and from 2.2448 (5) to 2.5014 (6) Šfor the equatorial and axial Cu-Cl bonds, respectively. Inter-molecular hydrogen bonds (N-H⋯Cl and O-H⋯Cl) and face-to-face π-π inter-actions stabilize the mol-ecular structure and give rise to a two-dimensional supra-molecular structure extending parallel to (101).

Crystal structure of trans-(1,8-dibutyl-1,3,6,8,10,13-hexa-aza-cyclo-tetra-decane-κ(4) N (3),N (6),N (10),N (13))bis-(isonicotinato-κO)nickel(II) determined from synchrotron data.

The title compound, [Ni(C6H4NO2)2(C16H38N6)], was prepared through self-assembly of a nickel(II) aza-macrocyclic complex with isonicotinic acid. The Ni(II) atom is located on an inversion center and exhibits a distorted octa-hedral N4O2 coordination environment, with the four secondary N atoms of the aza-macrocyclic ligand in the equatorial plane [average Ni-Neq = 2.064 (11) Å] and two O atoms of monodentate isonicotinate anions in axial positions [Ni-Oax = 2.137 (1) Å]. Intra-molecular N-H⋯O hydrogen bonds between one of the secondary amine N atoms of the aza-macrocyclic ligand and the non-coordinating carboxyl-ate O atom of the anion stabilize the mol-ecular structure. Inter-molecular N-H⋯N hydrogen bonds, as well as π-π inter-actions between neighbouring pyridine rings, give rise to the formations of supra-molecular ribbons extending parallel to [001].

Crystal structure of trans-(1,8-dibutyl-1,3,6,8,10,13-hexa-aza-cyclo-tetra-decane-κ(4) N (3),N (6),N (10),N (13))bis-(thio-cyanato-κN)nickel(II) from synchrotron data.

The crystal structure of the title compound, [Ni(NCS)2(C16H38N6)], has been determined from synchrotron data. The asymmetric unit consists of two halves of the complex mol-ecules which have their Ni(II) atoms located on inversion centres. The Ni(II) ions show a tetra-gonally distorted octa-hedral coordination geometry, with four secondary amine N atoms of the aza-macrocyclic ligand in the equatorial plane and two N atoms of the thio-cyanate anions in the axial positions. The average equatorial Ni-N bond length [2.070 (5) Å] is shorter than the average axial Ni-N bond length [2.107 (18) Å]. Only half of the macrocyclic ligand N-H groups are involved in hydrogen bonding. The complex mol-ecules are connected via inter-molecular N-H⋯S hydrogen bonds into two symmetry-independent one-dimensional polymeric structures extending along the b-axis direction. One of the n-butyl substituents of the macrocycle exhibits conformational disorder with a refined occupancy ratio of 0.630:0.370.

Crystal structure of trans-(1,8-dibutyl-1,3,6,8,10,13-hexa-aza-cyclo-tetra-decane-κ(4) N (3),N (6),N (10),N (13))bis-(perchlorato-κO)copper(II) from synchrotron data.

The structure of the title compound, [Cu(ClO4)2(C16H38N6)] has been determined from synchrotron data, λ = 0.62988 Å. The asymmetric unit comprises one half of the Cu(II) complex as the Cu(II) cation lies on an inversion center. It is coordinated by the four secondary N atoms of the macrocyclic ligand and the mutually trans O atoms of the two perchlorate ions in a tetra-gonally distorted octa-hedral geometry. The average equatorial Cu-N bond length is significantly shorter than the average axial Cu-O bond length [2.010 (4) and 2.569 (1) Å, respectively]. Intra-molecular N-H⋯O hydrogen bonds between the macrocyclic ligand and uncoordinating O atoms of the perchlorate ligand stabilize the mol-ecular structure. In the crystal structure, an extensive series of inter-molecular N-H⋯O and C-H⋯O hydrogen bonds generate a three-dimensional network.

Crystal structure of trans-(1,8-dibutyl-1,3,6,8,10,13-hexa-aza-cyclo-tetra-decane-κ(4) N (3),N (6),N (10),N (13))bis-(5-methyltetra-zolato-κN)nickel(II) from synchrotron data.

The structure of the title compound, [Ni(C2H3N4)2(C16H38N6)], has been characterized from synchrotron radiation. The asymmetric unit consists of one half of the Ni(II) complex mol-ecule, which is related to the other half-mol-ecule by an inversion center. The Ni(II) ion is coordinated by four secondary N atoms of the macrocyclic ligand in a square-planar fashion in the equatorial plane and by two N atoms of the 5-methyltetra-zolate anions in axial positions, resulting in a tetra-gonally distorted octa-hedral geometry. The average equatorial Ni-N bond length [2.060 (8) Å] is shorter than the axial Ni-N bond length [2.2183 (11) Å]. An intra-molecular N-H⋯N hydrogen bond between the secondary amine N atom of the macrocyclic ligand and the non-coordinating N atom of the 5-methyltetra-zolate ion stabilizes the mol-ecular structure. Moreover, an inter-molecular N-H⋯N hydrogen bond between the macrocyclic ligand and 5-methyltetra-zolate group gives rise to a supra-molecular sheet structure parallel to the bc plane.

Crystal structure of trans-(1,8-dibutyl-1,3,6,8,10,13-hexa-aza-cyclo-tetra-decane-κ(4) N (3),N (6),N (10),N (13))bis-(isonicotinato-κO)copper(II) from synchrotron data.

The title compound, [Cu(C6H4NO2)2(C16H38N6)] has been synthesized and characterized by structure analysis based on synchrotron data and by FT-IR spectroscopy. The asymmetric unit consists of half of the Cu(II) complex, the other half being completed by inversion symmetry. The Cu(II) ion has a tetra-gonally distorted octa-hedral coordination sphere with four secondary N atoms of the aza-macrocyclic ligand in the equatorial plane [Cu-Neq = 2.018 (12) Å] and two O atoms of the isonicotinate anions at the axial positions [Cu-Oax = 2.4100 (11) Å]. Intra-molecular N-H⋯O hydrogen bonds between one of the secondary amine N-H groups of the aza-macrocyclic ligand and the non-coordinating O atom of the isonicotinate ions stabilize the mol-ecular structure. Inter-molecular N-H⋯N hydrogen bonds between the other macrocyclic N-H group and the pyridine N atom of an adjacent isonicotinate anion as well as π-π inter-actions [centroid-to-centroid distance 3.711 (2) Å] lead to the formation of rods parallel to [001].

Crystal structure of di-chlorido-{2-[(2-hy-droxyeth-yl)(pyridin-2-ylmeth-yl)amino]-ethano-lato-κ(4) N,N',O,O'}iron(III) dihydrate from synchrotron data.

In the title compound, [Fe(C10H15N2O2)Cl2]·2H2O, the Fe(III) ion is coordinated by two N and two O atoms of the tetra-dentate 2-{(2-hy-droxy-eth-yl)(pyridin-2-ylmeth-yl)amino}-ethano-late ligand and by two chloride anions, resulting in a distorted octa-hedral coordination sphere. The average Fe-X (X = ligand N and O atoms) and Fe-Cl bond lengths are 2.10 and 2.32 Å, respectively. In the crystal, duplex O-H⋯O hydrogen bonds between the hydroxyl and eth-oxy groups of two neighbouring complexes give rise to a dimeric unit. The dimers are connected to the lattice water mol-ecules (one of which is equally disordered over two sets of sites) through O-H⋯Cl hydrogen bonds, forming undulating sheets parallel to (010). Weak C-H⋯Cl hydrogen bonds are also observed.

Cutoff probe using Fourier analysis for electron density measurement.

This paper proposes a new method for cutoff probe using a nanosecond impulse generator and an oscilloscope, instead of a network analyzer. The nanosecond impulse generator supplies a radiating signal of broadband frequency spectrum simultaneously without frequency sweeping, while frequency sweeping method is used by a network analyzer in a previous method. The transmission spectrum (S21) was obtained through a Fourier analysis of the transmitted impulse signal detected by the oscilloscope and was used to measure the electron density. The results showed that the transmission frequency spectrum and the electron density obtained with a new method are very close to those obtained with a previous method using a network analyzer. And also, only 15 ns long signal was necessary for spectrum reconstruction. These results were also compared to the Langmuir probe's measurements with satisfactory results. This method is expected to provide not only fast measurement of absolute electron density, but also function in other diagnostic situations where a network analyzer would be used (a hairpin probe and an impedance probe) by replacing the network analyzer with a nanosecond impulse generator and an oscilloscope.