Pressure-Induced Dehydration and Reversible Recrystallization of Dihydrogen-Bonded Sodium Borohydride Dihydrate NaBH·2HO.

Sodium borohydride dihydrate (NaBH·2HO) forms through dihydrogen bonding between the hydridic hydrogen of the BH ion and the protonic hydrogen of the water molecule. High-pressure structural changes in NaBH·2HO, observed up to 11 GPa through X-ray diffraction and Raman scattering spectroscopy, were analyzed to assess the influence of dihydrogen bonds on its crystal structure. At approximately 4.

Historical reconstruction of PFAS discharge into the Cooum River - Before and after the great Chennai flood in 2015.

Despite widespread research on PFAS, less is known in developing countries like India. PFAS levels in sediment core samples from the Cooum River of Chennai City (India) in 2014 and 2016 were estimated to evaluate the effect of the major flood event in 2015. Among 22 target PFAS in this study, 11 and 12 of them were detected in the 2014 and 2016 samples, respectively.

Development of an Integrating Sphere-Based Wide-Range Light Source System for the Linearity Evaluation of a Photodetector Used in Radiation Detection and Bioanalysis Instruments.

We developed a compact wide-range light source system for evaluating the linearity of photomultiplier tube (PMT) output. This system utilizes two integrating spheres equipped with a continuously variable slit and output aperture to modulate a stabilized light-emitting diode light source, producing an output light range as wide as seven orders of magnitude. To verify the wide linearity range of the integrating sphere system, three silicon photodiodes coupled with electric current readers monitored the light intensity and simultaneously confirmed each other's linearity.

Evaluation of the reagents and analytical behaviors of water-soluble phenylarsenic compounds via LC-MS/MS and HPLC-ICP-MS.

A phenylarsenic compounds, which contain arsenic (As), are chemical warfare agents; therefore, they are detected only in specific areas. Phenylarsenic compounds have gained significant research interest owing to their historical background, toxicology, and potential risks to human metabolism. However, research progress in this field has been limited because of the lack of standard materials, which ensure the chemical species and its concentration, required for analysis.

Measurement of trace I in natural water with ozone reaction for effective separation of spectral interferences.

Tandem quadrupole inductively coupled plasma mass spectrometry has the potential capability to measure I at extremely low concentration if spectral interferences from Xe and IH can be eliminated effectively. Ozone was introduced as the reaction gas, resulting significantly improved reactions of (I→IO) and (I→IO ), and permitted the highly sensitive measurement of I as IO and IO , helping eliminate spectral interferences related to Xe and IH . In isotopic ratio (I/I) analysis by measuring (I→IO )/(I→IO ), a blank ratio of 6.

Correction: Establishment and characterization of noro-VLP measurement by digital ELISA.

Correction for 'Establishment and characterization of noro-VLP measurement by digital ELISA' by Takema Hasegawa , , 2024, , 7089-7094, https://doi.org/10.1039/D4AY01012D.

Reversible Sliding Motion by Hole-Injection in Ammonium-Linked Ferrocene, Electronically Decoupled from Noble Metal Substrate by Crown-Ether Template Layer.

Artificial molecular machines, especially when based on wheel-and-axle complexes, can generate mechanical motions in response to external stimuli. Ferrocene (Fc) is a key component, but it decomposes at 300 K on metal surfaces. Here, a novel method is presented to construct and control the molecular complex composed of ammonium-linked ferrocene (Fc-amm) and tetrabrominated crown ether (BrCR) on a Cu(111) surface.

Mechanistic Insights into Oxygen-Independent DNA Photodegradation by Pheophorbide a: Implications for Future Photodynamic Therapy Applications.

This study explores the unique properties of Pheophorbide a (Phed a) in the photodegradation of G-quadruplex DNA under anoxic conditions, emphasizing its potential for photodynamic therapy (PDT) in hypoxic tumor environments. We used electron spin resonance (ESR), circular dichroism (CD), and nuclear magnetic resonance (NMR) spectroscopies to assess the radical generation and DNA interaction capabilities of Phed a compared to Pyropheophorbide a (Pyro a) under both oxygenated and anoxic conditions. Our results reveal that Phed a effectively degrades G-quadruplex DNA in the absence of oxygen, whereas Pyro a does not.

Characterization of acrylic phantom for use in quality assurance of BNCT beam output procedure.

The accelerator-based boron neutron capture therapy (BNCT) system has been approved for specific cases covered by health insurance, and clinical trials for new cases in Japan are currently being conducted on other systems. Owing to the progress of accelerator-based BNCT, the operation of medical physics must be rendered more efficient. A water phantom is used for the quality assurance (QA) of the BNCT beam output procedure; however, a solid phantom is preferred for routine QA because of its ease of use.

Quantification of uncertainties in reference and relative dose measurements, dose calculations, and patient setup in modern external beam radiotherapy.

Uncertainties in the steps of external beam radiotherapy (EBRT) affect patient outcomes. However, few studies have investigated major contributors to these uncertainties. This study investigated factors contributing to reducing uncertainty in delivering a dose to a target volume.

Evaluation of an ionization chamber characteristics for 222Rn calibration.

The National Metrology Institute of Japan plan to use an inner-through-type ionization chamber (IC) as a working standard to calibrate radon monitors. Novel methods to calibrate the IC were described, and the calibration factor, CF [Bq m -3 A-1], of the IC with its expanded uncertainty (k = 2) was evaluated to be (2.0 ± 0.

Use of calcite for evaluation of spectral resolution of Raman spectrometers.

Raman microscopes are widely used in various fields and their spectral resolutions differ greatly depending on the system and optical components. Thus, it is important to evaluate the spectral resolution of Raman systems under measurement conditions. Although both atomic emission lines and calcites have been used for the evaluation of spectral resolution and described in some guidelines, calcite is preferable because it contains information on laser width.

Wind velocity and dispersion/advection-diffusion of artificial droplets and droplet nuclei in a domed all-weather multi-purpose stadium.

To evaluate the COVID-19 infection risk and the effectiveness of countermeasures at mass-gathering events, we measured the dispersion and advective diffusion of artificial droplets and artificial droplet nuclei at the Tokyo Dome, Japan (capacity 55,000 people). We also measured and evaluated the effectiveness of wearing masks and increasing the space between seating areas. If people were seated facing forward, artificial droplets did not reach the mouths of surrounding people, suggesting low risk of droplet transmission.

Advancing Native Mass Spectrometry Toward Cellular Biology.

Protein structure, including various post-translational modifications and higher-order structures, regulates diverse biological functions. Native mass spectrometry (native MS) is a powerful analytical technique used to determine the masses of biomolecules, such as proteins and their complexes, while preserving their native folding in solution. This method provides structural information on the composition of monomers or complexes and the stoichiometry of subunits within each complex, significantly contributing to protein structural analysis.

Structural Phase Transitions of MgNiH Induced by NiH Molecular Ion Distortion and Metal Lattice Deformation under High Pressures.

Experimental observations indicate that pressure treatments transform the monoclinic and orthorhombic low-temperature phases of MgNiH into an unresolved pseudocubic phase even at room temperatures, resembling the temperature-induced phase transformation of the material. This pressure-induced phase transformation is anticipated to involve deformations of the tetrahedrally bonded NiH molecular ion and the metal lattice. However, the precise mechanism underlying this transformation remains unclear.

Establishment and characterization of noro-VLP measurement by digital ELISA.

Highly sensitive viral analytical techniques are essential tools for preventing the spread of infections. In this study, we established a digital enzyme-linked immunosorbent assay (ELISA) system to quantify norovirus proteins with high sensitivity. We used norovirus-like particles (noro-VLPs) as a surrogate for norovirus and constructed two digital ELISA systems using two different antibody pairs.

A reliable quantification of organophosphorus pesticides in brown rice samples for proficiency testing using Japanese official analytical method, QuEChERS, and modified QuEChERS combined with isotope dilution mass spectrometry.

The objective of the present study is to provide reliable concentration values as assigned values for target pesticides in brown rice samples used in proficiency testing (PT) organized by the Hatano Research Institute (HRI). The test samples for PT were prepared by immersing brown rice in the pesticide solution and using a spray dryer by the HRI. Homogeneity and stability assessments were performed for PT samples, and the relative uncertainties due to inhomogeneity and instability were 0.

Ozone reaction induced multiple ionic species for internal-cross-checkable determination of aluminium by tandem quadrupole inductively coupled plasma mass spectrometry.

Background: Aluminium is a mono-isotope element and can be determined by inductively coupled plasma mass spectrometry (ICP-MS). The measurement of aluminium by ICP-MS suffers potential spectral interferences from multiple elements, which make it challenging to ensure the reliability of the results. Fortunately, the availability of tandem quadrupole ICP-MS (i.

Inversion of the temperature dependence of thermal conductivity of hcp iron under high pressure.

Investigating how the thermal transport properties of iron change under extremely high pressure and temperature conditions, such as those found in the Earth's core, is a major experimental challenge. Over the past decade, there has been a great deal of discussion and debate surrounding the thermal conductivity of the iron-based Earth's core and its thermal evolution. One reason for this may be the variability in the experimentally obtained thermal conductivity of iron at high pressures and temperatures.

Determination of Calcium Isotopes Using Inductive Coupled Plasma-Tandem Mass Spectrometry with Ozone-Induced Oxidation.

In this study, we propose a new method for determination of calcium (Ca) isotopes using inductive coupled plasma-tandem mass spectrometry (ICP-MS/MS). The most abundant isotope of Ca, Ca, has a spectrum identical with that of argon (Ar), which is often used as the carrier gas in ICP-MS analysis. The detection capability for Ca is thus significantly reduced in the presence of Ar.

Optical-stimulated luminescence properties of undoped and Eu-doped LiCl transparent ceramics synthesized by spark plasma sintering method.

The undoped and Eu-doped LiCl transparent ceramics were synthesized, and their photoluminescence (PL) and optical stimulated luminescence (OSL) properties were evaluated. The PL properties of the undoped sample revealed as emission band due to a defect center. Additionally, the Eu-doped samples exhibited an emission band due to the 5d-4f transitions of Eu ions.

Magnification calibration of X-ray 3D microscopy using micro-line structures.

X-ray microscopy using computed tomography (CT) is an excellent three-dimensional imaging instrument. Three-dimensional X-ray microscopy (3DXRM) is a nondestructive imaging technique used to inspect internal and external structures in units of submicrometers or less. The 3DXRM, although attractive, is mostly used as an observation instrument and is limited as a measurement system in quantitative evaluation and quality control.