“Triple Observation Method (TOM)” to Discriminate Optically Autofluorescence from Porphyrins Versus that from Copper-Metallothioneins

We propose a conclusive difference observed between the excitation conditions required to observe porphyrins and copper-metallothioneins in cells and/or tissues using an ordinary fluorescence microscope. We have emphasized the importance of examining the spectral properties of the emissions to avoid any serious mistakes such as confusing porphyrins with copper-metallothioneins in the liver and kidneys. However, microspectrophotometry is not a conventional method for either histochemical, cytochemical, or pathological studies because microspectrophotometers are both expensive and difficult to operate. Therefore, we demonstrate a simple comparative method using ordinary excitation filter arrangements. When using our technique, it becomes possible to optically discriminate more accurately between the autofluorescence properties arising from porphyrins and those arising from copper-metallothioneins. We would like to name our simple technique “Triple Observation Method (TOM)”.     

Thermal neutron cross section and resonance integral of the reaction of135Cs(n,γ)136Cs: Fundamental data for the transmutation of nuclear waste

To determine the cross sections of the¹³⁵Cs(n,γ)¹³⁶Cs reaction, a sample of¹³⁵Cs included in a “standardized solution” of¹³⁷Cs was used as a target and irradiated in a reactor. The ratio of the atom number of¹³⁵Cs to that of¹³⁷Cs was determined to be 0.89±0.03 with a quadrupole mass spectrometer. The thermal cross section and the resonance integral measured in this study were determined to be 8.3±0.3 and 38.1±2.6 b respectively.     

Beyond Reduction Cocatalysts: Critical Role of Metal Cocatalysts in Photocatalytic Oxidation of Methane with Water**

Environmentally sustainable and selective conversion of methane to valuable chemicals under ambient conditions is pivotal for the development of next-generation photocatalytic technology. However, due to the lack of microscopic knowledge about non-thermal methane conversion, controlling and modulating photocatalytic oxidation processes driven by photogenerated holes remain a challenge. Here, we report novel function of metal cocatalysts to accept photogenerated holes and dominate selectivity of methane oxidation, which is clearly beyond the conventional concept in photocatalysis that the metal cocatalysts loaded on the surfaces of semiconductor photocatalysts mostly capture photogenerated electrons and dominate reduction reactions exclusively. The novel photocatalytic role of metal cocatalysts was verified by operando molecular spectroscopy combined with real-time mass spectrometry for metal-loaded Ga₂O₃ model photocatalysts under methane and water vapor at ambient temperature and pressure. Our concept of metal cocatalysts that work as active sites for both photocatalytic oxidation and reduction provides a new understanding of photocatalysis and a solid basis for controlling non-thermal redox reactions by metal-cocatalyst engineering.     

Apodized phase contrast microscopy for bright high contrast reveals motion of organelles

Optical Review - We have developed a high magnification objective lens performed with apodized phase contrast microscopy for bright high contrast, aiming to image finer intact intracellular...