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Science communication is commonly framed as a battle with ignorance and the field of radiological protection is not exempt from this tendency. By correcting deficits in the public's understanding of science, the expert is often imagined to be able to convince the public of its objective safety ('anzen'), thereby inspiring a sense of calm ('anshin'). In the wake of the 2011 Fukushima Daiichi disaster, however, the International Commission on Radiological Protection has sought to break with this tradition by organising a series of participatory seminars in which experts engage those affected by the disaster as equals. Drawing on ethnographic fieldwork, this article suggests that the Dialogue seminars can be best understood using the metaphor of therapy; using it to describe the premise, form, and objectives of the Dialogues with a view to identifying good practice for future radiological protection scenarios. [ABSTRACT FROM AUTHOR]

An investigation has been carried out of the effects of tool probe shape and size on the formation of surface composite by uniformly distributing SiC particles into a surface layer of an A1050-H24 aluminium plate through friction stir processing (FSP). Tool probes of three different diameters (3, 5 and 7 mm) and four different shapes (circular with threads, circular without threads, square and triangular) have been used to fabricate the surface layers at rotation speeds of 1500–2250 rev min–1 and a travelling speed of 1·66 mm s–1. The SiC particles were packed into a groove of 3 mm width and 1·5 mm depth cut on the aluminium plate and covered by an aluminium sheet of 2 mm thickness. A rotating tool was plunged into the plate through the cover sheet so that the tip of the probe reached beyond the bottom of the groove. As a result, it was found that the square probe dispersed the SiC particles homogeneously in the nugget zone compared with other probe shapes regardless of the rotation speeds. Furthermore, the distributed particles and also the aluminium matrix grain size became finer by the use of square probe than those of the other shapes. On the other hand, the wear rates of the square and triangular probes were higher than that of circular shape. The worn iron debris from the tool reacted with aluminium matrix and form fine iron aluminides compound dispersed in the nugget zone. The probe size had limited effects on the homogeneity of the SiC particles distribution in the nugget zone; the distribution of SiC particles obtained by triple FSP passes was less homogeneous when the probe size was smaller. Microhardness of the nugget zone was homogeneously increased to a level as high as 60 HV with tool of square probe shape after three passes to be compared with 23 HV of the aluminium matrix beside the nugget zone. [ABSTRACT FROM AUTHOR]

A Platinum (Pt) on pure ceria (CeO2) particles supported by carbon black (CB) was synthesised. The electrochemical activity of methanol oxidation reaction on synthesised Pt–CeO2/CB anodes was investigated. To develop this anode, the influence of surface area of CeO2 particles in Pt–CeO2/CB on anode properties was examined. The anode properties (i.e. onset potential and peak current density) were improved using fine CeO2 particles with high surface area. This indicates that higher activity on surface of CeO2 improves the anode properties. The anode properties on Pt high surface area CeO2/CB was better than that on Pt–Tin oxide(SnO2)/CB or Pt–Ru/carbon. The authors suggest that the rate determining steps of methanol oxidation reaction on Pt–CeO2/CB and other anodes such as Pt–SnO2/CB and Pt–Ru/carbon are different which accounts for the difference in performance. Therefore, it is concluded that a design of active surface of CeO2 is a key for development of Pt–CeO2/CB anode in polymer membrane fuel cells. [ABSTRACT FROM AUTHOR]

The effects of shielding gas composition on the properties and microstructure of single pass weld metals produced by GMA (gas metal arc) groove welding of 950 MPa class steel plates have been investigated. The shielding gas employed was a mixture of argon (Ar) and carbon dioxide (CO2) (0–25%), and the weld heat input was ∼3 kJ mm. With increasing CO2 content, the hardness of the weld metal decreased from 380 HV to 280 HV, and the absorbed energy of the Charpy impact test decreased from 130 J to 90 J. The microstructures of the weld metal, consisting primarily of low carbon martensite and carbide free bainite, became more bainitic as the CO2 content of the shielding gas was increased. It was also found that the MA constituent, embrittling microstructure, was formed in the granular bainitic area, the volume fraction of which increased with the CO2 content of the shielding gas. [ABSTRACT FROM AUTHOR]

Studies the microcirculation of brain tumors using perfusion imaging. Descriptional of the imaging technique; Differentiation of various types of tumors using perfusion imaging.

A feasibility investigation has been carried out of the formation of surface composite by uniformly distributing SiC particles 125 µm in size into a surface layer of an A 1050-H24 Al plate through friction stir processing (FSP). The SiC particle was filled into a groove cut on the Al plate, covered by an Al sheet 2 mm thick, and a rotating tool was penetrated from the cover sheet so that the probe tip reached a depth beyond the groove bottom. The effects of process parameters (rotation speed and travelling speed) and applying multiple passes on the distribution of SiC particle in the nugget zone were investigated. The effects of groove size and its position relative to the tool probe were also investigated. Applying multiple passes had a great effect on the homogeneity of the SiC particle distribution. At rotation speeds of 2000–3000 rev min-1, the SiC particles tended to cluster in some places in the nugget zone. By decreasing the rotation speed to 1000–1500 rev min-1, the SiC particle was distributed in almost all the nugget zone area when the groove was 2–3 mm wide and 15 mm deep. On the other hand, the stirring action of FSP was insufficient to distribute homogenously the SiC particles when the groove size was increased to 3×2 mm. By shifting the groove position towards the advancing side of the tool probe, the distribution of the SiC particles in the nugget zone became better. The defect free nugget zone with homogenously distributed SiC particles was obtained in a sample produced by FSP at rotation speeds of 1500 rev min-1 for the first pass and 1250 rev min-1 for the second and third passes. Microhardness of the nugget zone was increased to a level as high as 55 HV when the groove size was 3×15 mm. The effect of the rotation speed on the particles dispersion was discussed with particular reference to the vertical material flow in the nugget zone. [ABSTRACT FROM AUTHOR]

A shielding gas composition-controlled (SGC) welding process has been developed in which shielding gas composition changes periodically. This welding process has been successfully developed on the basis of computer simulation. A simulation model incorporating periodic change of shielding gas composition has been proposed and verified by welding experiments and observation of wire tip behaviour. In order to change shielding gas composition effectively, CO2 gas is locally and periodically introduced into Ar + 2%O2 shielding gas. As a result, CO2 and MIG arcs occur periodically during welding and the arc pole strongly oscillates over the groove wall. Oscillation control of the arc pole can be achieved by this shielding gas composition-controlled method. This newly developed welding system makes it possible to perform stable welding in narrow V-grooves and excellent welding joints are obtained with good fusion. [ABSTRACT FROM AUTHOR]

Purpose: To test the hypothesis that the simple assessment of signal intensity on T2-weighted MR images is predictive of the effect of hormonal treatment with gonadotropin-releasing hormone (GnRH) analogue.Material and Methods: The correlation between T2-weighted MR imaging of uterine leiomyomas and histologic findings was evaluated using 85 leiomyomas from 62 females who underwent myomectomy or hysterectomy. We also correlated the pretreatment MR images features obtained in 110 women with 143 leiomyomas with the effect of GnRH analogue treatment. The size (length x width x depth) of the leiomyoma was evaluated before and at 6 months after treatment by ultrasound.Results: The proportion of leiomyoma cell fascicles and that of extracellular matrix affected signal intensities of uterine leiomyomas on T2-weighted MR images. The amount of extracellular matrix was predominant in hypointense leiomyomas on T2-weighted images, while diffuse intermediate signal leiomyomas were predominantly composed of leiomyoma cell fascicles. Marked degenerative changes were noted in leiomyomas with heterogenous hyperintensity. The homogeneously intermediate signal intensity leiomyomas showed significant size reduction after treatment (size ratio; posttreatment volume/pretreatment volume 0.29+/-0.11). The size ratio for the hypointense tumors was 0.82+/-0.14, and 0.82+/-0.18 for the heterogeneously hyperintense tumors. There was a significant difference in the response to treatment between the homogeneously intermediate signal intensity leiomyomas and the hypointense or heterogeneously hyperintense leiomyomas (both p<0.01).Conclusion: Signal intensity on T2-weighted MR images depends on the amount of leiomyoma cell fascicles and extracellular matrix. Simple assessment of the MR signal intensity is useful in predicting the effect of GnRH analogue on uterine leiomyomas. [ABSTRACT FROM AUTHOR]

Probiotics are live microorganisms ingested for the purpose of conferring a health benefit on the host. Development of new probiotics includes the need for safety evaluations that should consider factors such as pathogenicity, infectivity, virulence factors, toxicity, and metabolic activity. Clostridium butyricum MIYAIRI 588® (CBM 588®), an anaerobic spore-forming bacterium, has been developed as a probiotic for use by humans and food animals. Safety studies of this probiotic strain have been conducted and include assessment of antimicrobial sensitivity, documentation of the lack of Clostridium toxin genes, and evaluation of CBM 588® on reproductive and developmental toxicity in a rodent model. With the exception of aminoglycosides, to which anaerobes are intrinsically resistant, CBM 588® showed sensitivity to all antibiotic classes important in human and animal therapeutics. In addition, analysis of the CBM 588® genome established the absence of genes for encoding for α, β, or ε toxins and botulin neurotoxins types A, B, E, or F. There were no deleterious reproductive and developmental effects observed in mice associated with the administration of CBM 588®. These data provide further support for the safety of CBM 588® for use as a probiotic in animals and humans. [ABSTRACT FROM AUTHOR]

Abstract Purpose: To evaluate MR findings at subacute and chronic stages after neonatal periventricular-intraventricular hemorrhage (PIVH), and to determine the clinical significance of follow-up MR. Material and Methods: Twenty-six children (estimated gestational age, 23–39 weeks; mean 29 weeks) with a history of previous PIVH underwent MR examination during their subacute and chronic clinical courses. PIVHs were initially detected with ultrasound examination in all cases. PIVH was divided into three grades (mild, moderate, and severe) according to the findings at the initial US studies, which were correlated to the MR findings. Results: Abnormal signal intensities related to hemorrhage were demonstrated in 10 of 21 patients (47.6%) on initial MR studies; the very low signal intensities on T2-weighted images found on the periventricular wall with a linear or a spotty shape had disappeared at one year after the initial US. The children with ventriculomegaly and periventricular leukomalacia (PVL) were increased in number on the follow-up studies. Conclusion: MR imaging provided valuable information about the consequences of neonatal PIVH such as developments of ventriculomegaly or PVL. It is noteworthy that hemorrhagic lesions could not be detected in half of the cases at the subacute or chronic stage of PIVH. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the MR dynamic patterns of neurohypophyseal germ cell tumors (GCTs) for differential diagnosis of infundibular diseases affecting young people.Material and Methods: Eleven patients with neurohypophyseal GCTs underwent dynamic MR studies with Tl-weighted spin-echo (SE) or turbo SE techniques. Other infundibular lesions, including adenohypophysitis (n=3), Langerhans' cell histiocytosis (LCH, n=2), and 1 hemangioblastoma from von Hippel-Lindau disease, were also evaluated. Serial images were obtained every 15 s (turbo SE) or 30 s (SE technique) for 240 s after rapid injection of contrast medium. The dynamic patterns were analyzed quantitatively with the contrast medium enhancement ratio.Results: On dynamic MR images, GCTs typically showed a gradual enhancement increase with a peak between 105 s and 180 s, while two showed a relatively rapid increase. LCH and hemangioblastoma showed a dynamic pattern similar to GCTs, while adenohypophysitis demonstrated a sharp rise and a steeper wash-out with an obvious peak before 90 s.Conclusion: Typical dynamic pattern of GCTs was the gradual enhancement increase without wash-out. Dynamic MR imaging can distinguish GCTs from adenohypophysitis, but is not useful for differentiation from LCH. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the detectability of hypervascular hepatocellular carcinomas (HCCs) in chronic liver damage with helical CT arterial portography (CTAP) and CT hepatic arteriography (CTHA).Material and Methods: Thirty-nine HCC patients who underwent CTAP and CTHA were studied. Diagnostic abilities of CTAP alone, CTHA alone, or combined CTAP and CTHA were evaluated by receiver operating characteristic (ROC) analysis. Fifty-three images with 53 HCC nodules were evaluated. Tumor size ranged from 5 to 90 mm (mean 22.8 mm). Sensitivities and specificities for all techniques were calculated.Results: ROC analysis showed the diagnostic ability significantly better with combined CTAP and CTHA (mean area under the ROC curve (Az)=0.95), or CTHA alone (Az=0.93) than CTAP alone (Az=0.87) (p<0.01). Combined CTAP and CTHA showed the best sensitivity (95.0%), followed by CTHA alone (88.1%) and CTAP alone (85.5%). The specificities of all three imaging techniques were relatively low (54.1% for combined CTAP and CTHA, 71.1% for CTHA alone, and 54.1% for CTAP alone) because of perfusion abnormalities of the liver parenchyma.Conclusion: The combination of CTAP and CTHA is superior to CTAP alone for detection of hypervascular HCCs. However, its specificity was relatively low in chronic liver damage. [ABSTRACT FROM AUTHOR]

AbstractPurpose: To evaluate MR cholangiopancreatography (MRCP) findings of intraductal papillary tumors of the pancreas and correlate them with histopathology. Material and Methods: Seventeen patients with intraductal papillary tumor of the pancreas underwent MRCP before surgery. MRCP findings were correlated to histopathology with regard to the presence of septa and excrescent nodules in the cystic lesion, communication between the cystic lesion and the main pancreatic duct (MPD), degree of dilatation of MPD, and dilatation of the common bile duct (CBD). Results: MRCP demonstrated septa in 17 cases (100%), excrescent nodules in 8 cases (47.1%), communication between the intraductal papillary tumor and the MPD in 14 cases (82.3%), dilatation of MPD over 50% in 6 cases (35.3%), and dilatation of CBD in 3 cases (17.6%). These findings showed excellent correlation with histopathology. The septum on MRCP corresponded with a layer of connective tissue with pancreatic duct epithelium. Excrescent nodules in the carcinomas consisted not only of malignant cells, but also of dysplasia and adenoma. Excrescent nodules in adenomas were consistent not only with minimal papillary growth of adenoma, but also with proliferation of fibrosis, and hematoma and organized fibrin with minimal fibrosis. Pancreatic tissue was affected by chronic pancreatitis in all cases. Cases with dilatation of CBD on MRCP were due to microscopic invasion by the carcinoma. Conclusion: MRCP appearances of intraductal papillary tumors are well correlated with the findings at histopathology. [ABSTRACT FROM AUTHOR]

AbstractObjective: To assess the usefulness of a postcontrast 3-D Fourier transform (3DFT) gradient-echo (GRE) technique in dural sinus invasion and extension of extraaxial intracranial tumors in comparison with a conventional spin-echo (SE) technique. Material and Methods: Fourteen consecutive patients with 15 extra-axial tumors in contiguity with the dural sinus, including 14 meningiomas and 1 adenoid cystic carcinoma, underwent postcontrast T1-weighted SE and GRE MR studies. Detectability of dural sinus invasion and extension was evaluated using two sequences by two neuroradiologists in a blinded manner and compared with surgical results. Quantitative analysis was also performed to calculate the contrast-to-noise ratio (CNR) between lesion and dural sinus on SE and GRE images. The data were analyzed statistically using a matched paired t-test. Results: In the qualitative evaluation, the detectability of dural sinus invasion in 3DFT-GRE images was superior to that using SE images. The mean CNR for all lesions was 3.86 on SE images and 5.63 on 3DFT-GRE images (p=0.03). Conclusion: For evaluation of dural sinus invasion and the extension of extra-axial tumors, postcontrast 3DFT-GRE MR images were superior to conventional SE images. [ABSTRACT FROM AUTHOR]

AbstractPurpose: To evaluate MR findings in early (T1 and T2 stages) glottic carcinomas and the predictive value of MR imaging for the rate of 5-year local control with radiation therapy. Material and Methods: Eighty-three patients with early glottic carcinomas were prospectively examined with MR at 1.5 T. MR investigation included unenhanced T1-weighted, T2-weighted, dynamic and contrast-enhanced T1-weighted images. Three patients with presumed advanced diseases on MR were initially treated with total laryngectomy and were excluded from the study. The remaining 80 patients were treated with radiation therapy with curative intent. Tumor detectability, size and relationship to the thyroid cartilage were determined on MR images. The MR findings were then correlated with the rate of local control. Results: Forty-eight of 80 lesions (60%) were detected on MR imaging. All detected lesions but 1 demonstrated increased signal on T2-weighted images. The lesions were best delineated on dynamic images (statistically significant). The 5-year local control rate with radiation therapy was 72%. Univariate analysis revealed clinical T stage, MR detectability, tumor size and relationship to the thyroid cartilage as significant predictors. Multivariate analysis revealed that the relationship to the thyroid cartilage was an independent factor. Conclusion: MR provides prognostic information about the results of definitive radiation therapy. To evaluate the tumor extension in lesions detected on precontrast MR images, contrast-enhanced dynamic images should be obtained. [ABSTRACT FROM AUTHOR]

Purpose: To identify features useful for differentiation between malignant and benign breast neoplasms using multivariate analysis of findings by MR imaging.Material and Methods: In a retrospective analysis, 61 patients with 64 breast masses underwent MR imaging and the time-signal intensity curves for precontrast dynamic postcontrast images were quantitatively analyzed. Statistical analysis was performed using a logistic regression model, which was prospectively tested in another 34 patients with suspected breast masses.Results: Univariate analysis revealed that the reliable indicators for malignancy were first the appearance of the tumor border, followed by the washout ratio, internal architecture after contrast enhancement, and peak time. The factors significantly associated with malignancy were irregular tumor border, followed by washout ratio, internal architecture, and peak time. For differentiation between benignity and malignancy, the maximum cut-off point was to be found between 0.47 and 0.51. In a prospective application of this model, 91% of the lesions were accurately discriminated as benign or malignant lesions.Conclusion: Combination of contrast-enhanced dynamic and postcontrast-enhanced MR imaging provided accurate data for the diagnosis of malignant neoplasms of the breast. The model had an accuracy of 91% (sensitivity 90%, specificity 93%). [ABSTRACT FROM AUTHOR]

Purpose: To determine the diagnostic value of MR imaging for tumors of the floor of the mouth and the effects of the tumors on the sublingual and submandibular glands.Material and Methods: Thirty-seven patients with proven squamous cell carcinoma of the floor of the mouth underwent MR imaging, including unenhanced T1-weighted, T2-weighted, dynamic, and contrast-enhanced T1-weighted images. The appearance of the tumor and the sublingual and submandibular glands was assessed qualitatively and quantitatively.Results: All tumors demonstrated replacement of the normal signal intensity in the adjacent sublingual gland. Twenty-one patients (57%) had abnormal signal intensity of the submandibular gland without tumor invasion, presumably secondary to submandibular duct obstruction by the tumor. Unenhanced T1-weighted images provided high contrast between tumor and sublingual gland. Tumors limited within the gland were well detected on unenhanced T1-weighted images. Large tumors extending beyond the gland were well delineated on dynamic images, but no better than on T2-weighted images.Conclusion: At MR imaging for tumor of the floor of the mouth, one must carefully evaluate the appearance of the sublingual and submandibular glands. Contrast-enhanced studies are unnecessary when the tumor is limited within the sublingual gland on precontrast MR images. [ABSTRACT FROM AUTHOR]