Modified inverse square sensitometry for the determination of the characteristic curve of radiographic screen/film systems.

To determine the characteristic curve of the radiographic screen/film systems in a short focal spot-film distance, the inverse square sensitometric method was modified by changing the radiation intensity with two kinds of filters. The characteristic curves obtained in the two exposure series with these two kinds of filters were overlapped to obtain a complete one. The characteristic curve thus obtained was almost the same as the one obtained by the original inverse square sensitometric method. The accuracy of the characteristic curves obtained by the modified method was well-reflected in the clinical radiographs.</p

New Stepwedge for Bootstrap Sensitometry in Medical Radiography

A new stepwedge has been developed for bootstrap sensitometry, which is used for determining the characteristic curve of radiographic screen/film systems. Since each step of the stepwedge is separated by the lead septum, flare generated under one step will not penetrate the region of another step. The metal of the stepwedge can be changed with various materials. Characteristic curves obtained with new stepwedge bootstrap (NSB) and conventional stepwedge bootstrap (CSB) techniques were compared with those obtained for screen/film systems with inverse sqare sensitometry. The inverse square method was used as the reference standard for accuracy. The NSB method provided characteristic curves that agreed well with those obtained using the inverse square method. The slope of the curve in the CSB method was lower than that in the inverse square or NBS method, because of scatter radiation. The shape of the characteristic curve from the NSB method did not vary with the materials of step metals (aluminum and copper). The cumulative error involved when using the bootstrap method is also discussed

Syntheses of wasabi phytoalexin (methyl 1-methoxyindole-3-carboxylate) and its 5-iodo derivative, and their nucleophilic substitution reactions

金沢大学大学院自然科学研究科生理活性物質科学金沢大学薬学部A simple synthetic method for methyl 1-methoxyindole-3-carboxylate, a phytoalexin isolated from Wasabia japonica, syn. Eutrema wasabi, and its 5-iodo derivative is reported. They underwent nucleophilic substitution reactions selectively at the 2-position

Syntheses of (±)-clavicipitic acid and its derivatives

金沢大学大学院自然科学研究科生理活性物質科学金沢大学薬学

Genomic organization and promoter function of the mouse uncoupling protein 2 (UCP2) gene1The nucleotide sequences reported in this paper will appear in the DDBJ, and GenBank/EMBL Data Bank with accession number AB012159.1

AbstractWe cloned and characterized the mouse uncoupling protein 2 (UCP2) gene and its promoter region. The gene spans approximately 6.3 kb and contains eight exons and seven introns. Two short exons are located in the 5′ untranslated region, and each of the remaining exons encodes one of the transmembrane domains. 3′-RACE analysis showed that a polyadenylation signal 257 bp downstream from the stop codon was functional. Primer extension analysis indicated a single transcriptional start site 369 bp upstream from the translational start site. The promoter region lacks both TATA and CAAT boxes but is GC-rich. A construct containing 1250 bp of the promoter region showed significant activity in all 6 cell lines examined, and the region between −160 and −678 bp exhibited strong positive regulatory activity. These features of the UCP2 gene are different from those of the UCP1 gene and may contribute to its ubiquitous expression

Phase segregated Cu₂₋ₓSe/Ni₃Se₄ bimetallic selenide nanocrystals formed through the cation exchange reaction for active water oxidation precatalysts

Control over the composition and nanostructure of solid electrocatalysts is quite important for drastic improvement of their performance. The cation exchange reaction of nanocrystals (NCs) has been reported as the way to provide metastable crystal structures and complicated functional nanostructures that are not accessible by conventional synthetic methods. Herein we demonstrate the cation exchange-derived formation of metastable spinel Ni₃Se₄NCs (sp-Ni₃Se₄) and phase segregated berzelianite Cu₂₋ₓSe (ber-Cu₂₋ₓSe)/sp-Ni₃Se₄ heterostructured NCs as active oxygen evolution reaction (OER) catalysts. A rare sp-Ni₃Se₄ phase was formed by cation exchange of ber-Cu₂₋ₓSe NCs with Ni²⁺ ions, because both phases have the face-centered cubic (fcc) Se anion sublattice. Tuning the Ni : Cu molar ratio leads to the formation of Janus-type ber-Cu₂₋ₓSe/sp-Ni₃Se₄ heterostructured NCs. The NCs of sp-Ni₃Se₄ and ber-Cu₂₋ₓSe/sp-Ni₃Se₄ heterostructures exhibited high catalytic activities in the OER with small overpotentials of 250 and 230 mV at 10 mA cm⁻² in 0.1 M KOH, respectively. They were electrochemically oxidized during the OER to give hydroxides as the real active species. We anticipate that the cation exchange reaction could have enormous potential for the creation of novel heterostructured NCs showing superior catalytic performance