Count rate characteristics and count loss correction of Positologica II: a whole body positron emission tomograph

This paper describes evaluation and correction of count rate characteristics of POSITOLOGICA II, a multi-slice whole body positron emission tomography system. The present study was performed using three phantoms; a 5 cm inner diameter, water-filled lucite cylinder, a 20 cm inner diameter, water-filled lucite cylinder and a chest phantom. After injection of high activity (about 1.85 GBq (50 mCi] of 13N ammonia into each phantom, rates of true coincidence, random coincidence and single photon detections were measured during decay of the isotope through more than two orders of magnitude of activity. At very high levels of activity, count rate characteristics of the system were saturated and limited to 660 kcps of total coincidence rate, which was the sum of rates in on-time and off-time windows, by the FIFO (first-in first-out) output frequency. Below those levels of activity the relationship between count loss and true coincidence rate was not unique but depended on the phantom configurations, suggesting that count loss correction using the above relationship was inadequate for quantitative study. However, the relationship between count loss and single rate was almost independent of the phantom configurations. Thus in conclusion count loss could be corrected using single rate for POSITOLOGICA II. A practical method of count loss correction was also proposed.     

Determination of arsenite, arsenate and monomethylarsonic acid in aqueous samples by gas chromatography of their 2,3-dimercaptopropanol (bal) complexes

Procedures are described for the determination of arsenite, arsenate and monomethylarsonic acid in aqueous samples. The arsenicals (after reduction of arsenic to the tervalent state) readily react with 2,3-dimercaptopropanol (BAL) to yield their BAL complexes. The products are extracted with benzene and introduced into a gas Chromatograph equipped with a flame-photometric detector for sulphur. One aliquot of sample is treated with stannous chloride solution and potassium iodide solution to reduce arsenate and monomethylarsonic acid, then BAL is added and the complexes are extracted with benzene. The extract is analysed for total inorganic As plus monomethylarsonic acid. Magnesia mixture and phosphate solution are added to another aliquot to remove arsenate by co-precipitation with magnesium ammonium phosphate. The precipitate is filtered off and arsenite determined in the filtrate. The detection limits are 0.02 ng of As for arsenate and arsenite and 0.04 ng of As for monomethylarsonic acid.     

A new oleanene glucuronide obtained from the aerial parts of Melilotus officinalis

A new oleanene glucuronide called melilotus-saponin O2 (1) was isolated together with three known ones (soyasaponin I, astragaloside VIII, wistariasaponin D) from the aerial parts of Melilotus officinalis (L.) Pallas (Leguminosae). The structure of 1 was determined to be 3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-xylopyranosyl- (1-->2)-beta-D-glucuronopyranosyl melilotigenin by spectroscopic and chemical methods.     

CuX2-mediated [4+2] benzannulation as a new synthetic tool for stereoselective construction of haloaromatic compounds

The CuX₂-mediated reaction of enynal units, including ortho-alkynylbenzaldehydes, with alkynes gives a variety of haloaromatic compounds stereoselectively in good to high yields. 2,2′-Binaphthyl skeletons are also readily prepared by the reaction of ortho-alkynylbenzaldehydes and diynes. The method was applied to the synthesis of poly-substituted tetracene derivatives.     

Au nanodot lattices with well‐controlled size and density for thin organic solar cells

Size, shape, and density‐controlled metal nanostructure, Au nanodot lattices fabricated by electron beam lithography, were embedded in thin organic solar cell consisting of PC₇₁BM:PCPDTBT. The effects of their size and density on device performance were examined. Even though dipole res‐onances of Au nanodots were consistent with the absorption range of the active materials, there were no improvements in device performance under any sizes and densities. In addition, under high volume density of Au nanodots to PEDOT:PSS layer, the device performance was deteriorated. These results indicated that not only size and density but also other factors which determine light scattering characteristics greatly affect the device performance of solar cells. (© 2015 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim)     

Raman sum rule and the relation to the infrared sum rule in La2-xSrxCuO4

Electronic Raman scattering has no sum rule in no and weak correlation, but the existence of sum rule has been proposed in strong correlation. The present Raman scattering disclosed that the first moment of the Raman susceptibility is proportional to the generalized moment of the optical conductivity in the metallic phase. The present experiment disclosed that a large amount of electronic states are incoherent states. The incoherent states are the relevant states for the superconductivity, because the gap opens in the incoherent states as well as the coherent states.     

A new synthesis of 2-sulfanyl allylic alcohols and alpha-sulfanyl ketones from carbonyl compounds and 1-chloroalkyl p-tolyl sulfoxides with carbon-carbon bond-formation

Reaction of lithium alpha-sulfinyl carbanions of 1-chloroalkyl p-tolyl sulfoxides with ketones or aldehydes at low temperature gave adducts in almost quantitative yields. Treatment of the adducts derived from ketones with trifluoroacetic anhydride (TFAA) in the presence of NaI in acetone gave alpha-sulfanyl allylic alcohols in good to quantitative yields. On the other hand, treatment of the adducts derived from aldehydes with TFAA and NaI resulted in the formation of alpha-sulfanyl ketones and/or alpha-sulfanyl allylic alcohols. These reactions offer a good method for the synthesis of the above-mentioned compounds from ketones and aldehydes with carbon-carbon bond-formation in two steps and in good yields.     

Metabolism of tomato steroidal glycosides in humans

Pregnane glycosides have been isolated in small amounts, along with the major components furostanol and spirostanol glycosides, from Dioscoreaceae, Taccaceae, and Solanaceae, suggesting that pregnane glycosides might be biosynthesized from furostanol and spirostanol glycosides. Recently, commercial natural foods composed of diosgenin have been used for the treatment of diseases such as osteoporosis and premenstrual syndrome in women. It is anticipated that diosgenin would be metabolized into a type of steroidal hormone, for instance progesterone, however, this metabolism has not been confirmed. Therefore, we have examined the metabolites in the urine of subjects who ingested tomatoes, which contain a considerable amount of the steroidal glycoside esculeoside A. The occurrence of steroidal hormones in the metabolites has been recognized. It has been proven that when a steroidal glycoside is administered, it is partly metabolized into a type of steroidal hormone exhibiting various physiological activities.     

A cyclic glucosyl ceramide acceptor as a versatile building block for complex ganglioside synthesis

A cyclic glucosyl ceramide (GlcCer) acceptor has been developed as a versatile building block for the synthesis of complex ganglioside. A macrocyclic GlcCer acceptor, which was the product of intramolecular glycosylation between glucose and ceramide, exhibited high reactivity during the coupling reactions with a variety of complex oligosaccharyl donors, thereby furnishing the corresponding ganglioside frameworks in high yields.