Some quantum chemical aspects of solvent effects on NMR parameters

The non-bonded interactions which occur between solute and solvent molecules are discussed and the various models which describe the interactions are presented. The models are employed, within a quantum chemical framework, to estimate the extent of medium effects on chemical shifts and spin-spin couplings. Comparison between the calculated and available experimental data is provided for some first row nuclei.     

The six bidecomposable graphs

A graph G is said to be decomposable if G can be decomposed into a cartesian product of two nontrivial graphs. G is bidecomposable if not only G but also its complement G is decomposable. We prove that there are only six bidecomposable graphs; 2K(2), C₄, Q ₃, K(2) ×(K(2) + K(2)) , K(3) × K(3).     

Determination of iron(III) and aluminum in solution with a piezoelectric quartz crystal coated with silicone oil

The frequency of the crystal connected to an integrated circuit oscillator changed on absorption of iron(III) or aluminum ar pH 3.8–5.8 and 5.0–6.0, respectively. Absorption of iron(III) at pH ≥ 5.0 was prevented by addition of excess of sulfate. Iron(III) was determined at pH 4.7; 5–100 μM solutions of both species may be determined with a r.s.d, of ≤3%.     

Mechanism of 67Ga uptake by an experimental abscess--permeability of plasma from blood vessels in abscessed tissue

In the previous paper, we reported that 67Ga was accumulated in abscess and uptake rate of 67Ga in abscess increased with time after the injection of 67Ga-citrate. The present study was undertaken to elucidate the influence of blood flow on the accumulation of 67Ga in abscess. Five days after subcutaneous injection of 0.2 ml of turpentine to the rats, 131I-human serum albumin (HSA) was injected intravenously to the rats. At an appropriate time after the injection (10 min to 6 days), uptake rates of 131I-HSA in abscess and normal tissues were measured. Similarly, 51Cr-red blood cells (RBC) were injected intravenously to the above rats and the uptake rates of 51Cr-RBC were also measured. One, three, and 24 hours after injection of 131I-HSA, the uptake rates of 131I-HSA in abscess were 1.32 %dose/g, 1.84 %dose/g, and 0.82 %dose/g, respectively. However, the uptake rates of 51Cr-RBC in abscess was very small, and the value was 0.14 %dose/g at 24 hours after the injection. In the case of abscess, blood in the tissue fluid was very little, but the permeability of 131I-HSA from the blood vessel in the tissue was much larger than that of normal tissues. From these facts, it was deduced that the accelerated permeability caused the abscess accumulation of 67Ga.     

A simple preparation of 1,3,5-triazine derivatives from 4-pyridones

The reaction of 4-pyridone or 4-quinolone with methyl or benzyl isocyanate in the presence of triethylamine or 1,1,3,3-tetramethylguanidine base gave the corresponding 1,3,5-triazine derivative (e. g., II) in a good yield via stepwise additions.