Double tracer autoradiography of bone tumor using 3H-thymidine and radionuclides for diagnostic purpose

Whole body distribution and accumulation of radionuclide for diagnostic purpose such as 99mTc-MDP (methylene diphosphonate), 67Ga-citrate (67Ga) and 201Tl-chloride (201Tl) in implanted osteosarcoma of human origin were evaluated by macroautoradiography of Balb/c nude mouse. 3H-thymidine of which uptake has a close relation to growth pattern of tumors was used for a partner of target nuclide in double tracer technique to examine the distribution characteristics. Separated distribution pattern of coupled nuclides was imaged by a difference both of half life and energy of radiation between radionuclides. The distribution pattern of each target nuclide and 3H-thymidine were compared to clarify distribution characteristics respectively in specimen. 67Ga and 201Tl were taken around the tumor and the mode of their distribution was identical to that of 3H-thymidine. Uptake of 67Ga in tumor was much higher. 99mTc-MDP accumulated in the central zone of the tumor and its pattern was quite different from that of 3H-thymidine. From above result it was demonstrated that the accumulation mechanism of 67Ga, 201Tl and 99mTc-MDP are quite different in the tumor each other. So we concluded that our method of double tracer technique was useful for evaluation of distribution pattern of radionuclides for diagnostic purpose.     

Photoluminescence excitation spectroscopy of GaP1−xNx alloys: conduction-band-edge formation by nitrogen incorporation

We have investigated the conduction-band-edge formation in GaP_1−xN_x alloys by nitrogen incorporation into GaP using photoluminescence excitation (PLE) spectroscopy. The PLE spectra of GaP_1−xN_x alloys with various nitrogen concentrations show that the absorption edge shifts to lower energies with increasing nitrogen concentration. From the nitrogen concentration dependence of the absorption edge energy we found that the conduction-band-edge formation in GaP_1−xN_x alloys originates from the formation of the A line.     

Preparation of ketones by direct reaction of grignard reagents with acid chlorides in tetrahydrofuran

Grignard reagents react with acid chlorides in tetrahydrofuran at low temperature to produce ketones in excellent yields. The results reported here strongly indicate the importance of the solvent in Grignard reagent chemistry.     

Cooperative cascade emission

An experimental and theoretical study has been performed on the generating process of a cascade emission in a sample three-level system where the ground and the highest excited levels have been initially brought into a coherent superposition state by two-proton excitation. Experimentally the forward and the backward emissions of the upper and the lower transitions of the cascade were observed in Li, and each of the emission lines showed a characteristic growth. In the theoretical analysis it is found that a dephasing in the prepared superposition state is required for the cascade emission as a coupled three level superradiance to grow. Using the concepts of delay time, threshold, lifetime, etc. of the cooperative cascade emission, the general behavior of the experimental results is explained.     

Determination of the spatial distribution of abnormal EEG and MEG from current dipole in inhomogeneous volume conductor

Summary The electrical conductivity of brain lesions varies with pathological situations such as edema and calcification. The effect of the tissue inhomogeneities of brain lesions on spatial distributions of electrical potentials and magnetic fields over the surface of the head was studied by means of a computer simulation. Paper presented at the ?IV International Workshop on Biomagnetism?, held in Rome, September 14–16, 1982.     

Relations for supermatrices in hartree-fock-roothaan equation

Relations have been proved by which the double summations over symmetry subspecies appearing in J- and K- supermatrices of the Hartree-Fock-Roothaan equation are reduced to a single summation.     

Combustion synthesis of high-quality diamond film suitable for application in electronic devices

The purpose of this research is to elucidate the electrical characteristics of a diamond film synthesized by combustion flame and synthesize a diamond film suitable for application in electronic devices. When the film contains amorphous carbon, the dielectric loss increases, i.e., the electrical characteristics of the diamond film are degraded. We employed three methods to decrease the amorphous carbon in the diamond film—the detection of the optimal equivalence ratio, addition of hydrogen into synthesizing gas, and heat treatment (annealing) of the diamond film. All these methods can decrease the amount of amorphous carbon effectively, thus systematically changing the factors influencing the optimal synthesis for improving the electric characteristics of the film. We have successfully developed a method for preparing a high-quality diamond film with excellent electrical characteristics that has no dielectric loss in the wide frequency range (10²–10⁸ Hz).     

EPR and ENDOR studies of the distal site coordination of shark heart myoglobin

The coordination of small molecules and ions at the sixth position of ferric myoglobins (Mb) from the heart muscle of two species of shark,Lamna ditropis (LD) andPrionace glauca (PG), was studied in frozen solution by electron paramagnetic resonance (EPR) and electron-nuclear double resonance (ENDOR) spectroscopy. The results were compared with those of horse heart Mb (EQMb). From our preliminary studies of the absorption spectra and partial amino acid sequences of PGMb and LDMb, we expected PGMb to have glutamine (Gln E7) in place of the distal His E7 that is highly conserved in most animals and present in LDMb. Here, we have used proton ENDOR to show that a water molecule coordinates to the ferric ion in both LDMb and PGMb at pH 6.3. The observed proton hyperfine coupling constant of the coordinating water molecule of PGMb is smaller than those of LDMb and EQMb, which suggests weaker coordination of the water molecule in PGMb, consistent with the absent distal His (E7). Coordination of several exogenous ligands at the distal site was examined by EPR. PGMb showed a coordination behavior different from that of LDMb and EQMb for 1-methylimidazole, 4-methylimidazole and SCN^?, suggesting that its distal site is less sterically hindered. On the basis of the ENDOR and EPR results, we assigned the distal residues of PGMb and LDMb as Gln and His, respectively.     

Radial transport characteristics of fast ions due to energetic-particle modes inside the last closed-flux surface in the compact helical system

The internal behavior of fast ions interacting with magnetohydrodynamic bursts excited by energetic ions has been experimentally investigated in the compact helical system. The resonant convective oscillation of fast ions was identified inside the last closed-flux surface during an energetic-particle mode (EPM) burst. The phase difference between the fast-ion oscillation and the EPM, indicating the coupling strength between them, remains a certain value during the EPM burst and drives an anomalous transport of fast ions.