Exciton-relaxation dynamics in lead halides

We survey recent comprehensive studies of exciton relaxation in the crystals of lead halides. The luminescence and electron-spin-resonance studies have revealed that excitons in lead bromide spontaneously dissociate and both electrons and holes get self-trapped individually. Similar relaxation has been also clarified in lead chloride. The electron-hole separation is ascribed to repulsive correlation via acoustic phonons. Besides, on the basis of the temperature profiles of self-trapped states, we discuss the origin of luminescence components which are mainly induced under one-photon excitation into the exciton band in lead fluoride, lead chloride, and lead bromide.Comment: REVTeX, 5 pages, 5 figure

Self-trapped electrons and holes in PbBr2_2 crystals

We have directly observed self-trapped electrons and holes in PbBr$_{2}$ crystals with electron-spin-resonance (ESR) technique. The self-trapped states are induced below 8 K by two-photon interband excitation with pulsed 120-fs-width laser light at 3.10 eV. Spin-Hamiltonian analyses of the ESR signals have revealed that the self-trapping electron centers are the dimer molecules of Pb$_2$$^{3+}$ along the crystallographic a axis and the self-trapping hole centers are those of Br$_2$$^-$ with two possible configurations in the unit cell of the crystal. Thermal stability of the self-trapped electrons and holes suggests that both of them are related to the blue-green luminescence band at 2.55 eV coming from recombination of spatially separated electron-hole pairs.Comment: 8 pages (7 figures, 2 tables), ReVTEX; revised the text and figures 1, 4, and

Psychophysical evaluation of calibration curve for diagnostic LCD monitor

金沢大学大学院医学系研究科量子医療技術学Purpose. In 1998, Digital Imaging Communications in Medicine (DICOM) proposed a calibration tool, the grayscale standard display function (GSDF), to obtain output consistency of radiographs. To our knowledge, there have been no previous reports of investigating the relation between perceptual linearity and detectability on a calibration curve. Materials and methods. To determine a suitable calibration curve for diagnostic liquid crystal display (LCD) monitors, the GSDF and Commission Internationale de l\u27Eclairage (CIE) curves were compared using psychophysical gradient δ and receiver operating characteristic (ROC) analysis for clinical images. Results. We succeeded in expressing visually recognized contrast directly using δ instead of the just noticeable difference (JND) index of the DICOM standard. As a result, we found that the visually recognized contrast at low luminance areas on the LCD monitor calibrated by the CIE curve is higher than that calibrated by the GSDF curve. On the ROC analysis, there was no significant difference in tumor detectability between GSDF and CIE curves for clinical thoracic images. However, the area parameter Az of the CIE curve is superior to that of the GSDF curve. The detectability of tumor shadows in the thoracic region on clinical images using the CIE curve was superior to that using the GSDF curve owing to the high absolute value of δ in the low luminance range. Conclusion. We conclude that the CIE curve is the most suitable tool for calibrating diagnostic LCD monitors, rather than the GSDF curve. © Japan Radiological Society 2006

Self-trapped states and the related luminescence in PbCl2_2 crystals

We have comprehensively investigated localized states of photoinduced electron-hole pairs with electron-spin-resonance technique and photoluminescence (PL) in a wide temperature range of 5-200 K. At low temperatures below 70 K, holes localize on Pb$^{2+}$ ions and form self-trapping hole centers of Pb$^{3+}$. The holes transfer to other trapping centers above 70 K. On the other hand, electrons localize on two Pb$^{2+}$ ions at higher than 50 K and form self-trapping electron centers of Pb$_2$$^{3+}$. From the thermal stability of the localized states and PL, we clarify that blue-green PL band at 2.50 eV is closely related to the self-trapped holes.Comment: 8 pages (10 figures), ReVTEX; removal of one figure, Fig. 3 in the version

Impact of functional studies on exome sequence variant interpretation in early-onset cardiac conduction system diseases

Aims The genetic cause of cardiac conduction system disease (CCSD) has not been fully elucidated. Whole-exome sequencing (WES) can detect various genetic variants; however, the identification of pathogenic variants remains a challenge. We aimed to identify pathogenic or likely pathogenic variants in CCSD patients by using WES and 2015 American College of Medical Genetics and Genomics (ACMG) standards and guidelines as well as evaluating the usefulness of functional studies for determining them. Methods and Results We performed WES of 23 probands diagnosed with early-onset (<65 years) CCSD and analyzed 117 genes linked to arrhythmogenic diseases or cardiomyopathies. We focused on rare variants (minor allele frequency < 0.1%) that were absent from population databases. Five probands had protein truncating variants in EMD and LMNA which were classified as “pathogenic” by 2015 ACMG standards and guidelines. To evaluate the functional changes brought about by these variants, we generated a knock-out zebrafish with CRISPR-mediated insertions or deletions of the EMD or LMNA homologs in zebrafish. The mean heart rate and conduction velocities in the CRISPR/Cas9-injected embryos and F2 generation embryos with homozygous deletions were significantly decreased. Twenty-one variants of uncertain significance were identified in 11 probands. Cellular electrophysiological study and in vivo zebrafish cardiac assay showed that 2 variants in KCNH2 and SCN5A, 4 variants in SCN10A, and 1 variant in MYH6 damaged each gene, which resulted in the change of the clinical significance of them from “Uncertain significance” to “Likely pathogenic” in 6 probands. Conclusions Of 23 CCSD probands, we successfully identified pathogenic or likely pathogenic variants in 11 probands (48%). Functional analyses of a cellular electrophysiological study and in vivo zebrafish cardiac assay might be useful for determining the pathogenicity of rare variants in patients with CCSD. SCN10A may be one of the major genes responsible for CCSD. Translational Perspective Whole-exome sequencing (WES) may be helpful in determining the causes of cardiac conduction system disease (CCSD), however, the identification of pathogenic variants remains a challenge. We performed WES of 23 probands diagnosed with early-onset CCSD, and identified 12 pathogenic or likely pathogenic variants in 11 of these probands (48%) according to the 2015 ACMG standards and guidelines. In this context, functional analyses of a cellular electrophysiological study and in vivo zebrafish cardiac assay might be useful for determining the pathogenicity of rare variants, and SCN10A may be one of the major development factors in CCSD

Cutoff Values of Serum IgG4 and Histopathological IgG4+ Plasma Cells for Diagnosis of Patients with IgG4-Related Disease

IgG4-related disease is a new disease classification established in Japan in the 21st century. Patients with IgG4-related disease display hyper-IgG4-gammaglobulinemia, massive infiltration of IgG4+ plasma cells into tissue, and good response to glucocorticoids. Since IgG4 overexpression is also observed in other disorders, it is necessary to diagnose IgG4-related disease carefully and correctly. We therefore sought to determine cutoff values for serum IgG4 and IgG4/IgG and for IgG4+/IgG+ plasma cells in tissue diagnostic of IgG4-related disease. Patients and Methods. We retrospectively analyzed serum IgG4 concentrations and IgG4/IgG ratio and IgG4+/IgG+ plasma cell ratio in tissues of 132 patients with IgG4-related disease and 48 patients with other disorders. Result. Serum IgG4 >135  mg/dl demonstrated a sensitivity of 97.0% and a specificity of 79.6% in diagnosing IgG4-related disease, and serum IgG4/IgG ratios >8% had a sensitivity and specificity of 95.5% and 87.5%, respectively. IgG4+cell/IgG+ cell ratio in tissues >40% had a sensitivity and specificity of 94.4% and 85.7%, respectively. However, the number of IgG4+ cells was reduced in severely fibrotic parts of tissues. Conclusion. Although a recent unanimous consensus of all relevant researchers in Japan recently established the diagnostic criteria for IgG4-related disease, findings such as ours indicate that further discussion is needed

理科教材の試作とその学習効果の測定 : 第1報告:「わゴム」による「てこ」の学習

In the teaching of the principle of levers and pulleys, weights and balances have been used as conventional teaching aids. We have found, however, that we can use rubber bands instead of weights for this purpose, and have devised a simple experimental board using ordinary rubber rings and a scale by means of which pupils can perform various kinds of force experiments. (Fig. 2.7 ) By replacing weights with rubber bands we have found that this board is of advantage in presenting illustrative examples of force which an ordinary weight-balance apparatus fails to present. For instance, a lever model with its fulcrum at one end can be eaily made, and even the magnitude of the force exerted at the fulcrum can be shown by the number of stretched rubber bands. (Fig. 2.6 ) Besides being economical and easy to handle children soon get familiar with the apparatus because of their play experiences with rubber bands. It is to be noted that in the learning of force by our device, force is regarded as a dynamic tension produced by the expansion of rubber, rather than as a static gravitational force exerted. by the suspended weights. Thus we have introduced a new learning situation. The purpose of the present study was to attempt to construct and evaluate a more effective apparatus for the teaching of force and quilibrium. We have been also concerned with the sequence of the study in close relation to children\u27s understanding of force through their everyday activities. A preliminary study was made of 147 pupils (4th and 6th grades) at an elementary school. The procedures of the experiment and evaluation test were revised on the basis of an analysis of the findings in the preliminary study, and a later, full-scale experiment (using a "before-after" design) was made of 328 fourth-grade pupils of two different schools, each divided into four classes. In each school, two classes studied the principle of the lever with the rubber band apparatus, one being conducted mainly through teacher\u27s demonstration experiments and the other through pupils\u27 group experiments. The other two classes were used as control groups to cover the same subject using conventional apparatus (weights and balances). Several tests were given to examine the homogeneity of the four classes, and it was found that there were no significant differences among the classes. The findings obtained from the tests and the problems suggesting further investigation are summarized as follows: 1) The analysis of the before and after tests revealed that there was no significant difference in the effectiveness of learning between the "rubber band" groups and the "weight" groups, although there was a difference in the amount of learning between the two schools. This means that our teaching device was as effective as the conventional weight-balance apparatus. The precise functional difference in effectiveness of the two different approaches is still to be investigated further through continuing studies having more detailed design. 2) A correlation analysis, especially devised for this study, showed that there was a considerable amount of individual difference in the gains between before and after tests. The scores of the before test were negatively correlated with the gains. This means that the lower ability group in the before test made greater gains through this experiment. 3) An item analysis for the paired problems, one using rubber bands and the other with weights, indicated that these two types of learning were transferable, because both the "weight" and the "rubber band" groups equally gained on the problems using the material (rubber band or weight) which they did not actually use in the class