[en] Major active faults generally consist of systems of a number of fractures with various dimensions, and contain a lot of ground water. Rn gas, moving with underground water, tends to accumulate along faults and emit γ-ray while it decays down to Pb through Bi. Therefore, it has been shown by a number of works that γ-ray intensity is generally high near the core of the major active fault and the γ-ray survey is one of the effective methods to look for the core of the major active fault. However, around the area near the tips of faults, a number of complicated sub-fault systems and the corresponding complicated geological structures are often seen and it has not been investigated well about what can be the relationship between the intensity distribution of γ-ray and the fault systems. In order to investigate the relationship in an area near the tips of major faults well, therefore, we carried out the γ-ray survey at about 1,100 sites in an area of about 2 km x 2 km that has the tips of the two major right lateral faults with significant thrusting components. We also investigated the lineaments by using the topographic map published in 1895 when artificial construction was seldom seen in the area and we can easily see the natural topography. In addition, we carried out the γ-ray survey in an area far from the fault tip to compare with the results in the area with the fault tips. Then: (1) we reconfirmed that in the case of the middle of the major active fault, γ-ray intensity is high in the limited area just adjacent to the core of the fault. (2) However, we found that in the case of the tip of the major active fault, high γ-ray intensity is seen in much wider area with clear lineaments that is inferred to be developed associated with the movement of the major faults. (author)

[en] Purpose: To use digitally reconstructed radiography (DRR) and digitally compressed portal images in distant consultation using a telecommunications network, the verification performance of DRR and digitally compressed portal images on the image console was investigated. Methods and Materials: A human thoracic phantom was scanned with computed tomography (CT). Radiotherapy was planned at 5 different anatomic locations. A digitally reconstructed radiograph was made; verification films of the phantom were then taken with 6-MV X-rays. The treatment center was intentionally dislocated. Fifty sets of DRR and portal images were seen by 7 doctors on a conventional view-box (view-box method) to judge whether the treatment center was dislocated. These image sets were digitalized by a film scanner, compressed to 1/10 Joint Photographic Experts Group (JPEG) format, and compared on an image console by the same physicians (image-console method). The verification performance of the image console method was compared with that of the view-box method by means of receiver operating characteristic (ROC) analysis. Clinically, 159 portal-image-sets were verified with the image-console method and the appropriateness of the decision was later assessed by the view-box method. Results: The accuracy of the treatment verification was estimated to be 88.8% by the conventional view-box method and 88.3% by the image-console method. There was no statistically significant difference in the verification performances of the conventional method (Az=0.86±0.02) and the image console method (Az=0.84±0.07). Frequent digital image-processing modification was positively related to the accuracy of verification. Clinically, there were 3 (1.8%) major corrections, 31 (19.5%) minor corrections, and 123 cases with no correction. No further correction was called for by the re-evaluation using the view-box method. Conclusion: The verification performance of DRR and digitally compressed portal images on the image console was as accurate as the conventional method. Distant consultation using DRR and portal images through telecommunication is usable in clinical practice

[en] Hepatic blood flow and portal shunts were clinically studied with Tc-99m per-rectal portal scintigraphy in 51 patients with liver cirrhosis. RI time-activity curves of the liver and heart were used to define 3 patterns: type I = RI activity was more intense in the liver than in the heart, type II = more intense in the liver at one min and that in the heart at 15 min, or type III = less intense in the liver than in the heart. Four (8 %) of the patients had type 1, 22 (43 %) type II, and 25 (49 %) type III. Esophageal varices and splenomegaly were significantly associated with type III (p < 0.01). Regarding laboratory findings indicative of the impairment of liver function, there was no significant difference among the three types of RI activity. Indocyamine green tolerance test showed significantly higher R15 in the group with type III than in the other two groups (p < 0.05). Three other patients with idiopathic portal hypertension without liver function disturbance had type III. Per-rectal portal scintigraphy will be of help as a noninvasive tool for reflecting not only portal shunts but also hepatic blood flow and for predicting the severity of liver cirrhosis. (Namekawa, K.)

[en] Herein we present our research on synthesis of silver nanoparticles (AgNPs) on cellulose nanofibers (CN) by a facile procedure using dopamine hydrochloride (Dopa), as reducing agent. The CN were produced by deacetylation of electrospun cellulose acetate (CA) nanofibers. The CN were then treated with 2 mg/mL of Dopa in 1 M Tris HCl buffer (pH 8.5) followed by soaking in 150 mM AgNO₃ solution for generation of AgNPs. The samples were characterized with SEM, XRD, FESEM, EDX, XPS, TEM, FTIR analysis and antibacterial assays. Synthesis of AgNPs was confirmed by XRD, XPS and TEM analysis. The TEM images demonstrated CNAgNP samples well decorated with AgNPs. Sizes of the spherical AgNPs, calculated by Debye–Scherrer method, were 20 nm. Antibacterial test results confirmed excellent bacterial growth inhibition properties of CNAgNP on agar plates and in liquid medium against E. coli and S. aureus strains. The relative cell viability (CFU/mL) test results demonstrated excellent bactericidal potential of the CNAgNP samples against the tested strains. The CNAgNP prepared by an environmentally benign process would thus be a promising nano-biocomposite for antibacterial applications.