Radiocarbon dating of an ancient Japanese document “Minamoto no Yoritomo Sodehan Migyosho” by accelerator mass spectrometry

We measured radiocarbon age of an ancient document “Minamoto no Yoritomo Sodehan Migyosho”. The content tells that it was issued in 1189 by “Minamoto no Yoritomo” known as the virtually first shogun in Japan to grant “Matsugi” family the privilege of controlling craftsmen of foundry industry. Paleographical views, however, suggested that it can be a counterfeit. The radiocarbon dating clarified that the document was written not in the 12th but after the 16th century.     

Enzyme-less amperometric biosensor for l-ascorbate using poly-l-histidine-copper complex as an alternative biocatalyst

A poly-l-histidine(PLH)-copper(II) complex can be used as an alternative biocatalyst in an O(2) detection-type amperometric enzyme-less l-ascorbate (AsA) sensor. The PLH-Cu(II) membrane was simply prepared by entrapping the PLH in polyacrylamide gel and subsequent treatment of the gel with CuCl(2) solution. This enzyme-less biosensor can be used over a relatively wide pH region from 4 to 11 and enables precise determination of AsA (RSD less than 3%, n=10) at pH 7.0. The fundamental performance characteristics (sensitivity, response time, and linear range) of this PLH-Cu(II)-based sensor is comparable to those of a native ascorbate oxidase-based sensor. Unfortunately, the selectivity is inherently rather low and, as a result, the response was degraded in the presence of higher concentrations (more than mM order) of quinones. However, reducing sugars caused no interference and the sensor could be used to detect AsA in some fruits and drinks. This enzyme-less sensor has excellent stability for at least 3 months of repeated analysis (more than 300 samples) without loss of ordinal activity.     

A novel transformation of a 1 : 1 : 1 racemic complex of 2,2'-dihydroxy-1,1'-binaphthyl, Me4N+ Cl- and MeOH into a conglomerate in the solid state by heating or contact with MeOH vapour

The title racemate-to-conglomerate transformation which occurs in the solid state on heating or contact with MeOH vapour has been studied by IR and DTA spectral measurements, microscopic observation, and by X-ray structural and X-ray powder diffraction analysis.     

5-Fluorouracil derivatives. XX. Synthesis and antitumor activity of 5'-O-unsaturated acyl-5-fluorouridines

Various kinds of 5'-O-unsaturated acyl 5-fluorouridines were synthesized to obtain 5-fluorouridine derivatives with low toxicity and high antitumor activity. Antitumor activity of the compounds against L-1210 leukemia in mice was examined, and the 5'-O-4-pentenoyl derivative showed the highest antitumor activity.     

Rapid determination of sulphonamides in milk using liquid chromatographic separation and fluorescamine derivatization.

A simple and selective method is presented for the multiple residue determination of eight sulphonamides in consumers' milk. The drugs are sulphisomidine (ID), sulphadiazine (DZ), sulphamerazine, sulphadimidine, sulphamonomethoxine, sulphamethoxazole, sulphadimethoxine and sulphaquinoxaline (SQ). The milk sample was deproteinized with the same volume of 2 M hydrochloric acid and filtered. A 1-ml volume of the filtrate was mixed with 1 ml each of 1.25 M sodium acetate solution and a buffer (pH 3.0) for derivatization with 0.6 ml of 0.02% fluorescamine solution in acetone. A high-performance liquid chromatographic analysis was carried out on a C18 column with a mobile phase of acetonitrile-2% acetic acid (3:5) at 55 degrees C using a fluorescence detector at an excitation wavelength of 405 nm and an emission wavelength of 495 nm. Average recoveries at fortification levels of 2, 5 and 10 ng/ml were 114%, 109% and 106%, respectively. Relative standard deviations were 1-4% at 10 ng/ml for ID, 5 ng/ml for DZ and SQ and 2.5 ng/ml for the other five sulphonamides. The method was applied to 25 milk samples and all appeared to be free from the drugs.     

Synthesis of 4,5-diaminopyrrolo[1,2-a]quinoline derivatives by annulation of N,N-dialkyl[2-(pyrrol-1-yl)benzylidene]ammonium salts in the presence of an isocyanide

A facile synthetic method for 4,5-diaminopyrrolo[1,2-a]quinoline derivatives has been developed. Treatment of 2-(pyrrol-1-yl)benzaldehydes with secondary amine hydrochloride/NaI/TMSCl/Et₃N in the presence of an isocyano compound leads to the formation of 4-alkyl(or aryl)amino-5-dialkylaminopyrrolo[1,2-a]quinolines.     

Myoglobin-CO substate structures and dynamics: multidimensional vibrational echoes and molecular dynamics simulations

Spectrally resolved infrared stimulated vibrational echo data were obtained for sperm whale carbonmonoxymyoglobin (MbCO) at 300 K. The measured dephasing dynamics of the CO ligand are in agreement with dephasing dynamics calculated with molecular dynamics (MD) simulations for MbCO with the residue histidine-64 (His64) having its imidazole epsilon nitrogen protonated (N(epsilon)-H). The two conformational substate structures B(epsilon) and R(epsilon) observed in the MD simulations are assigned to the spectroscopic A(1) and A(3) conformational substates of MbCO, respectively, based on the agreement between the experimentally measured and calculated dephasing dynamics for these substates. In the A(1) substate, the N(epsilon)-H proton and N(delta) of His64 are approximately equidistant from the CO ligand, while in the A(3) substate, the N(epsilon)-H of His64 is oriented toward the CO, and the N(delta) is on the surface of the protein. The MD simulations show that dynamics of His64 represent the major source of vibrational dephasing of the CO ligand in the A(3) state on both femtosecond and picosecond time scales. Dephasing in the A(1) state is controlled by His64 on femtosecond time scales, and by the rest of the protein and the water solvent on longer time scales.     

Prospective study to assess the clinical efficacy of bone scintigraphy--some analyses of clinical data

The value of preoperative bone scans in patients with primary breast and prostate cancer was evaluated prospectively. Of 414 patients with breast cancer, clinical stage I is 14, II is 219, IIIA is 59, IIIB is 39 and IV is 14. Of 88 patients with prostate cancer, clinical stage I is 14, II is 15, III is 18 and IV is 41. 11 percent of patients with breast cancer and 54 percent of patients with prostate cancer had bone metastases. Clavicle, ribs, thoracic spine, lumbar spine and pelvis metastasized most frequently. The incidences of bone metastases were 18.4% with Scirrhous carcinoma, 15.4% with Medullary tubular carcinoma and 3.8% with Papillotubular carcinoma. The methodology and results of ROC analysis were described in our other papers. Some results of data analysis were described in this paper.     

XPS study of one-dimensional compounds: TiS3

X-Ray photoelectron spectra of TiS₃ with a one-dimensional structure were measured. TiS₃ may be regarded as Ti⁴⁺(S₂)^2?S^2? with pairs of S atoms (S₂) and isolated S atoms. The spectra of the sulfur core-levels are assigned by comparison with those of TiS₂, where all S atoms are largely separated. The binding energy of the S₂ pairs is found to be 1.4 eV higher than that of the isolated S atoms, which is consistent with the larger negative charge of the isolated atoms. The structures of the valence band of TiS₃ are discussed in terms of a molecular orbital scheme for the S₂ pairs.     

High performance liquid chromatography post-column chemiluminescence determination of sulfonamide residues in milk at low concentration levels using bis[4-nitro-2-(3,6,9-trioxadecyloxycarbonyl)phenyl] oxalate as chemiluminescent reagent

The determination of seven sulfonamides by means of HPLC with chemiluminescence detection is proposed for the first time. The analytes are derivatized with fluorescamine, separated and subsequently they participate in the post-column chemiluminescence (CL) peroxyoxalate system using imidazole as a catalyst. Among the different peroxyoxalates tested, bis[4-nitro-2-(3,6,9-trioxadecyloxycarbonyl)phenyl] oxalate provides higher sensitivities and stabilities, avoiding precipitation problems. A rigorous optimization of the significant variables by means of experimental designs has been developed in order to reconcile the chromatographic conditions with the CL reaction. The method provides detection limits in the low microgl(-1) range and has been satisfactorily applied to the analysis of spiked raw milk samples.