Spectroscopy of Pionic Atoms in ^{122}Sn(d,^{3}He) Reaction and Angular Dependence of the Formation Cross Sections

We observed the atomic 1s and 2p states of π^{-} bound to ^{121}Sn nuclei as distinct peak structures in the missing mass spectra of the ^{122}Sn(d,^{3}He) nuclear reaction. A very intense deuteron beam and a spectrometer with a large angular acceptance let us achieve a potential of discovery, which includes the capability of determining the angle-dependent cross sections with high statistics. The 2p state in a Sn nucleus was observed for the first time. The binding energies and widths of the pionic states are determined and found to be consistent with previous experimental results of other Sn isotopes. The spectrum is measured at finite reaction angles for the first time. The formation cross sections at the reaction angles between 0° and 2° are determined. The observed reaction-angle dependence of each state is reproduced by theoretical calculations. However, the quantitative comparison with our high-precision data reveals a significant discrepancy between the measured and calculated formation cross sections of the pionic 1s state.

Magnetic-field-induced phase separation via spinodal decomposition in epitaxial manganese ferrite thin films

In this study, we report about the occurrence of phase separation through spinodal decomposition (SD) in spinel manganese ferrite (Mn ferrite) thin films grown by Dynamic Aurora pulsed laser deposition. The driving force behind this SD in Mn ferrite films is considered to be an ion-impingement-enhanced diffusion that is induced by the application of magnetic field during film growth. The phase separation to Mn-rich and Fe-rich phases in Mn ferrite films is confirmed from the Bragg's peak splitting and the appearance of the patterned checkerboard-like domain in the surface. In the cross-sectional microstructure analysis, the distribution of Mn and Fe-signals alternately changes along the lateral (x and y) directions, while it is almost homogeneous in the z-direction. The result suggests that columnar-type phase separation occurs by the up-hill diffusion only along the in-plane directions. The propagation of a quasi-sinusoidal compositional wave in the lateral directions is confirmed from spatially resolved chemical composition analysis, which strongly demonstrates the occurrence of phase separation via SD. It is also found that the composition of Mn-rich and Fe-rich phases in phase-separated Mn ferrite thin films deposited at higher growth temperature and in situ magnetic field does not depend on the corresponding average film composition.

Comparing the risk of hepatitis B virus reactivation between direct-acting antiviral therapies and interferon-based therapies for hepatitis C

Hepatitis B virus (HBV) reactivation has been reported during antihepatitis C treatment in patients with hepatitis C virus (HCV) and HBV co-infection. We aimed to evaluate the frequency and risk factors of HBV reactivation during anti-HCV therapy and compared those between interferon (IFN)-free direct-acting antiviral (DAA) therapies and IFN-based therapies. Three hundred and twenty-two patients with HCV infection receiving anti-HCV therapy were retrospectively screened. The baseline HBV infection statuses of all eligible patients and the HBV-DNA level of all patients with current or previous HBV infection were examined at the end of treatment. In patients with baseline anti-HBs positivity, changes in anti-HBs titre were evaluated. Of 287 patients who met the inclusion criteria, 157 had current (n=4) or previous (n=153) HBV infection; 85 were treated with IFN-free DAA therapies and 72 were treated with IFN-based therapies. Six patients experienced HBV reactivation (n=2) or HBV reappearance (n=4) after IFN-free DAA therapies, while no patient developed HBV reactivation after IFN-based therapies. The risk factors of HBV reactivation or reappearance were DAA therapies and a reduction in anti-HBs titre to <12 mIU mL^-1 by the end of treatment. The decline changes of anti-HBs titre were significantly higher in patients treated with DAA therapies. Although HBV reactivation hepatitis was not observed, three of four patients with HBV reactivation or reappearance after achieving HCV eradication had viremia 8 weeks after completion of therapy. A significant proportion of patients develop HBV reactivation or reappearance without hepatitis after IFN-free DAA therapies. Low levels of anti-HBs and their decrease to <12 mIU mL^-1 after treatment are significant risk factors for HBV reactivation or reappearance.

Correlation between the Expression of P-Glycoprotein and Multidrug-Resistant Phenotype in Transitional Cell Carcinoma of the Urinary Tract

The expression of a multidrug-resistant (MDR) gene product, P-glycoprotein, was examined immunohistochemically in 41 transitional cell carcinomas (TCCs) of the urinary tract. In 23 of these, chemosensitivity to adriamycin (ADM) and vinblastine (VBL) was also assessed by a microtiter succinate dehydrogenase inhibition test and the correlation between the expression of P-glycoprotein and MDR phenotype was investigated. P-glycoprotein was detected in 13 (72.2%) of the 18 untreated TCCs of the upper urinary tract (UUT), 6 (31.6%) of the 19 untreated TCCs of the bladder, and all of the 4 TCCs treated with M-VAC chemotherapy, respectively. Fourteen (87.5%) of the 16 TCCs with a positive expression of P-glycoprotein were resistant to ADM and VBL, whereas all of the 4 TCCs sensitive to both drugs were negative in the expression of P-glycoprotein. The succinate dehydrogenase activity of TCCs with a positive expression of P-glycoprotein was significantly higher than that of TCCs with a negative expression of P-glycoprotein (P < 0.05). Thus, there was a good correlation between the expression of P-glycoprotein and MDR phenotype in the chemosensitivity test. These results suggest that intrinsic MDR exists in some TCCs of the urinary tract, particularly UUT, and that the immunohistochemical investigation of P-glycoprotein may be useful for predicting the MDR phenotype in TCCs of the urinary tract.

Domain-wall conduction in ferroelectric BiFeO3 controlled by accumulation of charged defects

Mobile charged defects, accumulated in the domain-wall region to screen polarization charges, have been proposed as the origin of the electrical conductivity at domain walls in ferroelectric materials. Despite theoretical and experimental efforts, this scenario has not been directly confirmed, leaving a gap in the understanding of the intriguing electrical properties of domain walls. Here, we provide atomic-scale chemical and structural analyses showing the accumulation of charged defects at domain walls in BiFeO₃. The defects were identified as Fe⁴⁺ cations and bismuth vacancies, revealing p-type hopping conduction at domain walls caused by the presence of electron holes associated with Fe⁴⁺. In agreement with the p-type behaviour, we further show that the local domain-wall conductivity can be tailored by controlling the atmosphere during high-temperature annealing. This work has possible implications for engineering local conductivity in ferroelectrics and for devices based on domain walls.

Impact of inadequate initial antimicrobial therapy on mortality in patients with bacteraemic cholangitis: a retrospective cohort study

OBJECTIVES

Acute cholangitis is a common cause of bacteraemia resulting in severe sepsis or septic shock. The impact of the appropriate initial antimicrobial therapy on short-term mortality in bacteraemic cholangitis has not been well investigated.

METHODS

We conducted a retrospective cohort study of patients with bacteraemic cholangitis at two large tertiary care centres in Tokyo, Japan between 2009 and 2015. We determined the factors associated with 30-day all-cause mortality from the date of drawing the first positive blood culture, using a multivariate logistic regression analysis.

RESULTS

We identified 573 patients with bacteraemic cholangitis (median age, 77 years; male, 58.3%). The 30-day all-cause mortality rate was 6.6% (38/573). Inadequate initial antimicrobial therapy occurred in 133 (23.2%) patients. Factors associated with 30-day all-cause mortality included the Charlson co-morbidity index score >3 (adjusted odds ratio (aOR) 4.12; 95% CI 1.18-14.38), jaundice (total bilirubin >2.5 mg/dL) (aOR 3.39; 95% CI 1.46-7.89), septic shock within 48 h of the first positive blood culture (aOR 3.34; 95% CI 1.42-7.89), biliary obstruction due to hepatobiliary malignancy (aOR 8.00; 95% CI 2.92-21.97), and inadequate initial antimicrobial therapy (aOR 2.78; 95% CI 1.27-6.11).

CONCLUSIONS

Inadequate initial antimicrobial therapy was an important, modifiable determinant of survival.