Validation of radiative transfer computation with Monte Carlo method for ultra-relativistic background flow

We developed a three-dimensional radiative transfer code for an ultra-relativistic background flow-field by using the Monte Carlo (MC) method in the context of gamma-ray burst (GRB) emission. For obtaining reliable simulation results in the coupled computation of MC radiation transport with relativistic hydrodynamics which can reproduce GRB emission, we validated radiative transfer computation in the ultra-relativistic regime and assessed the appropriate simulation conditions. The radiative transfer code was validated through two test calculations: (1) computing in different inertial frames and (2) computing in flow-fields with discontinuous and smeared shock fronts. The simulation results of the angular distribution and spectrum were compared among three different inertial frames and in good agreement with each other. If the time duration for updating the flow-field was sufficiently small to resolve a mean free path of a photon into ten steps, the results were thoroughly converged. The spectrum computed in the flow-field with a discontinuous shock front obeyed a power-law in frequency whose index was positive in the range from 1 to 10 MeV. The number of photons in the high-energy side decreased with the smeared shock front because the photons were less scattered immediately behind the shock wave due to the small electron number density. The large optical depth near the shock front was needed for obtaining high-energy photons through bulk Compton scattering. Even one-dimensional structure of the shock wave could affect the results of radiation transport computation. Although we examined the effect of the shock structure on the emitted spectrum with a large number of cells, it is hard to employ so many computational cells per dimension in multi-dimensional simulations. Therefore, a further investigation with a smaller number of cells is required for obtaining realistic high-energy photons with multi-dimensional computations

<ORIGINAL>Microradiography in the differentiation and definite diagnosis of odontomas

The present study evaluated the usefulness of microradiography in differentiny and making a definite diagnosis of odontomas. A surgically removed odontoma from a 14-year-old girl was used here. The specimen was sectioned at approximately 100μm thickness and ground to 50μm. Microradiographic images were obtained using soft X-ray equipment (Sofron, Japan) under the conditions of : tube voltage, 10kVp ; tube current, 5mA ; FSD 7.5cm ; and exposure time, 20min. The images were evaluated by comparing to images obtained by histological procedures. The results showed that the microradiographic images had almost the same resolution as that of the microscopic images

Effects of indole-3-carbinol and phenethyl isothiocyanate on bile and pancreatic juice excretion in rats

Bile and pancreatic juice contain a number of parameters for cancer chemoprevention. Indole-3-carbinol (I3C) and phenethyl isothiocyanate (PEITC), which are hydrolytic products of brassica plants, have been established to be anti-cancer agents. Here, we developed a method for the continuous and selective sampling of bile and pancreatic juice, and the effects of I3C and PEITC on bile and pancreatic excretion and γ-glutamyl transpeptidase (γ-GTP) activity in the samples were investigated. Male Fisher 344 rats (eight weeks of age) were challenged intragastrically with I3C (150 mg/kg) or PEITC (160 mg/kg) for five days. Twenty-four hours after the final administration, cannulation was undertaken into the rats’ bile and pancreatic ducts, and the bile and pancreatic juice were separately collected for 48 h. In this rat model, bile was stably excreted, and the bile and pancreatic excretion of the control rats was 21.9±1.4 ml/48 h and 12.8±1.7 ml/48 h, respectively. Bile excretion for the first 24 h significantly increased in the I3C- or PEITC-treated rats compared with the control rats. In the case of pancreatic juice, excretion during the first 24 h significantly increased in the PEITC-treated rats. In bile, γ-GTP activity was significantly increased for the first 24 h in the I3C- and PEITC-treated rats, but no difference was observed in the pancreatic juice. Increases of bile excretion and γ-GTP activity in bile might be a factor involved in the anti-cancer effect of I3C and PEITC. Our rat model described here is a useful tool for the study of cancer chemoprevention

The Diagnosis of Hypovascular Hepatic Lesions Showing Hypo-intensity in the Hepatobiliary Phase of Gd-EOB- DTPA-enhanced MR Imaging in High-risk Patients for Hepatocellular Carcinoma

The aim of this study was to evaluate the histologic diagnosis of hypovascular hepatic lesions showing hypointensity on hepatobiliary phase images of gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced MRI (EOB-MRI). In 38 patients with hepatocellular carcinoma (HCC) after curative treatments and 18 patients with liver cirrhosis, 105 hypovascular nodules that were hypointense at the hepatobiliary phase of EOB-MRI were biopsied and the clinical usefulness of these EOB-MRI findings for the diagnosis of HCC was examined. Of the 105 nodules (median diameter＝12mm), 78 (74.3%), 11 (10.5%), and 16 (15.2%) were diagnosed as HCC, dysplastic, and non-neoplastic, respectively. The positive predictive value (PPV) of hypointensity at the hepatobiliary phase of EOB-MRI for the diagnosis of HCC increased to 77-90% when combined with the following factors: washout appearance on the delayed phase of triple-phase CT, hyperintensity in diffusion-weighted image of MRI, or the appearance of a hypoechoic part in ultrasonography. PPV increased to 100% when all 3 factors were positive. A relatively large proportion of hypovascular lesions that showed hypo-intensity in the hepatobiliary phase were confirmed to be HCC, and the accuracy of HCC increased when combined with other imaging findings

Risk factors of first bite syndrome

Objective : First bite syndrome is a complication of surgical resection of parapharyngeal space tumors and the development of cramping pain in the parotid region with the first bite of a meal. The present study aimed to identify the potential risk factors for the development of first bite syndrome. Methods : We retrospectively reviewed 30 consecutive patients with parapharyngeal space tumors who had been surgically treated between August 2003 and December 2015 at our department. Results : The tumor site (prestyloid or retrostyloid) and surgical approach (transcervical-parotid, transparotid, or transcervical) were not correlated with the development of first bite syndrome. Ligation and mobilization of the external carotid artery was significantly correlated with the development of first bite syndrome. Moreover, patients with complete resection of the parotid gland did not experience first bite syndrome. Discussion : The present findings suggest that concomitant surgical settings of 1) sympathetic denervation of the parotid gland with ligation of the external carotid artery or injury of the sympathetic nerve plexus around the external carotid artery during its mobilization, and 2) residual parotid gland tissue are risk factors for the development of first bite syndrome after surgical resection of parapharyngeal space tumors

Vegetacija in ekologija barij v Sloveniji

We confirmed infection of 2 patients with Borrelia miyamotoi in Japan by retrospective surveillance of Lyme disease patients and detection of B. miyamotoi DNA in serum samples. One patient also showed seroconversion for antibody against recombinant glycerophosphodiester phosphodiesterase of B. miyamotoi. Indigenous relapsing fever should be considered a health concern in Japan