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Generally, reactivation of hepatitis B virus (HBV) infection is induced by the administration of immunosuppressants or anticancer agents, but reactivation without such drugs has rarely been reported. Here we report an elder case with spontaneous reactivation of HBV replication accompanied by hepatitis B surface antigen (HBsAg) mutations. A 69-year-old man with a history of diabetes mellitus and chronic kidney disease (CKD) was found to be positive for HBsAg (0.072 IU/ml) in June 2018. In May 2019, marked hepatic dysfunction and increased HBsAg (2533.2 IU/ml) were observed when he visited the hospital due to diarrhea and worsening of CKD. At that time, hepatitis B surface antibody (HBsAb) was positive (268.9 mIU/ml) and HBV DNA was 6.0 log IU/ml. After treatment with entecavir, HBV DNA and HBsAg rapidly decreased. Full-genome HBV sequence analysis revealed that the patient was infected with HBV of subgenotype B1 and it had an "a" determinant mutation M133L in the S gene coding HBsAg. Notably, both HBsAg and HBsAb were positive at the time of HBV reactivation, suggesting that the HBV with these mutations escaped from neutralization by HBsAb. This case suggests that immune escape mutations could play an important role in spontaneous HBV reactivation.

The association of Helicobacter pylori infection with aspirin-induced gastropathy is controversial. H. pylori infection exerts diverse effects on gastric acid secretion. In this study, the interaction between H. pylori infection and aspirin was investigated with reference to the individual gastric acid secretion level in H. pylori-positive subjects.Ninety-three (81 men, mean age: 70 years) long-term low-dose aspirin takers were prospectively enrolled. H. pylori infection was evaluated by serum IgG antibody determination, and gastrin-stimulated acid output was assessed with the endoscopic gastrin test. H. pylori-positive aspirin-takers were classified into 2 subgroups (hyposecretors and non-hyposecretors). The grade of gastric mucosal injury was assessed endoscopically according to the modified Lanza score; intensive aspirin-induced gastropathy was defined as a modified Lanza score of ≥4. Multiple logistic regression analyses were used to adjust for potential confounders.With H. pylori-negative patients taken as the reference, H. pylori infection was found to be positively associated with intensive gastropathy among non-hyposecretors, with an odds ratio (OR) (95 % confidence interval [CI]) of 4.2 (1.1-17.1), while the infection was negatively associated with gastropathy among hyposecretors, with an OR (95 % CI) of 0.3 (0.08-0.9). Aspirin-induced gastropathy occurred preferentially in the antrum among H. pylori-positive non-hyposecretors, while it affected the fundus among H. pylori-positive hyposecretors.The effect of H. pylori infection on the aspirin-induced gastropathy was biphasic depending on the individual gastric acid secretion level. In the presence of sufficient amounts of gastric acid, H. pylori infection and aspirin could synergistically damage gastric mucosal integrity, while in the absence of sufficient amounts of gastric acid, the synergistic effect could be completely counteracted and the infection could even suppress the aspirin-induced gastropathy.

Woodceramic thin films were prepared onto alumina sheet and glass slide substrates by conventional radio frequency sputtering in an argon plasma. A woodceramic disk, 100 mm in diameter, sintered at 850°C was used as a target. The deposition rate was about 90 nm/h for 200 W input power. Remarkable differences were observed in the characteristics of films depending on the substrate temperature. Films prepared below 100°C had insulating properties, ρ > 106 Ω cm, and had transmission in the visible region (λ > 600 nm), and had smooth surfaces. Increasing the substrate temperature causes sharp a decrease in the film resistivity and the growth of grain was 3–5 μm. The film prepared at 300°C had semiconductor characteristics with an energy gap of about 0.05 eV.

Wood and bamboo ceramics are newly developed porous carbon materials from wood and bamboo impregnated with resin, and they possess some special properties and can be expected to be used as electromagnetic materials, absorbents, catalyst carrier materials, etc. In this work, the graphitization behavior of wood and bamboo ceramics was investigated by X-ray diffraction. Experimental results show that the d002 spacing of the bamboo carbon, wood and bamboo ceramics decreased and the apparent graphite crystallite size Lc(002) increased with the increase of graphitization temperature. However, even after heat treatment at 3273 K, the d002 and Lc(002) value was only about 0.341 and 9 nm, respectively. These results indicate that all of the bamboo carbon, wood and bamboo ceramics investigated are typical non-graphitizable carbon or hard carbon.