Effects of Boride Orientation and Si Content on High-Temperature Oxidation Resistance of Directionally Solidified Fe–B Alloys

In this work, the as-cast directionally solidified (DS) Fe–B alloys with various Si contents and different boride orientation were designed and fabricated, and the as-cast microstructures and static oxidation behaviors of the DS Fe–B alloys were investigated extensively. The as-cast microstructure of the DS Fe–B alloys consists of the well-oriented Fe₂B columnar grains and α-Fe, which are strongly refined by Si addition. The oxidation interface of the scales in the DS Fe–B alloy with 3.50 wt.% Si demonstrates an obvious saw-tooth shaped structure and is embedded into the alternating distributed columnar layer structures of the DS Fe–B alloy with oriented Fe₂B and α-Fe matrix, which is beneficial to improve the anti-peeling performance of the oxide film compared with lower amounts of Si addition in DS Fe–B alloys with oriented Fe₂B [002] orientation parallel to the oxidation direction (i.e., oxidation diffusion direction, labeled as Fe₂B_// sample). In the DS Fe–B alloys with oriented Fe₂B [002] orientation vertical to the oxidation direction (i.e., labeled as Fe₂B_⊥ sample), due to the blocking and barrier effect of laminated-structure boride, Si is mainly enriched in the lower part of the oxide film to form a dense SiO₂ thin layer adhered to layered boride. As a result, the internal SiO₂ thin layer plays an obstructed and shielded role in oxidation of the substrate, which hinders the further internal diffusion of oxygen ions and improves the anti-oxidation performance of the Fe₂B_⊥ sample, making the average anti-oxidation performance better than that of the Fe₂B_// sample.     

Hepatitis B among University Population: Prevalence,Associated Risk Factors,Knowledge Assessment,and Treatment Management

Background: Very few studies have been reported on hepatitis B in the State of Azad Jammu and Kashmir, Pakistan, and none of them are specific to the prevalence and causes of hepatitis B spread among educational institutes. This study aimed to estimate the prevalence of hepatitis B infection and its associated risk factors among the University of AJ and K population. Methods: An observational, cross-sectional, and analytical study was conducted with 7015 students and employees. Hepatitis B was detected by rapid immunochromatographic tests (ICTs), enzyme-linked immunosorbent assay (ELISA), and real-time quantitative PCR. A questionnaire and interview method was used to assess the disease knowledge and associated risk factors with hepatitis B through Chi-square, Fisher’s exact test, and paired t-test. Results: Of the participants, 150 (2.13%) were found positive for the hepatitis B surface antigen (57.3% male and 42.7% female). Only 0.3% participants were found fully vaccinated against the hepatitis B virus. Among ethnic groups, the Syed tribe was found more prevalent for hepatitis B infection (40.6%), while use of contaminated mourning blades (95% CI: p = 0.0001) was found as an overlooked risk factor. Hepatitis preventive awareness sessions were found to be very significant (p = 0.0001). Conclusions: The study showed that an overlooked risk factor is playing a key role in the spread of HBV in a tribe living worldwide, which must be addressed globally to eradicate hepatitis B. In Pakistan, a country-wide annual HBV vaccination program should be launched to control hepatitis B.     

Vaccination Decreases the Infectious Viral Load of Delta Variant SARS-CoV-2 in Asymptomatic Patients

The Delta variant of SARS-CoV-2 has caused many breakthrough infections in fully vaccinated individuals. While vaccine status did not generally impact the number of viral RNA genome copies in nasopharyngeal swabs of breakthrough patients, as measured by Ct values, it has been previously found to decrease the infectious viral load in symptomatic patients. We quantified the viral RNA, infectious virus, and anti-spike IgA in nasopharyngeal swabs collected from individuals asymptomatically infected with the Delta variant of SARS-CoV-2. Vaccination decreased the infectious viral load, but not the amount of viral RNA. Furthermore, vaccinees with asymptomatic infections had significantly higher levels of anti-spike IgA in their nasal secretions compared to unvaccinated individuals with asymptomatic infections. Thus, vaccination may decrease the transmission risk of Delta, and perhaps other variants, despite not affecting the amount of viral RNA measured in nasopharyngeal swabs.     

Evaluation of the Hepatocellular Carcinoma Predictive Scores PAGE-B and mPAGE-B among Brazilian Patients with Chronic Hepatitis B Virus Infection

Hepatitis B virus (HBV) is intrinsically oncogenic and related to hepatocellular carcinoma (HCC). Predictive scores of HCC have been developed but have been poorly studied in admixed populations. Therefore, we aimed to evaluate the performance of PAGE-B and mPAGE-B scores for HCC prediction in HBV Brazilian patients and factors related to HCC occurrence. This is a retrospective study that evaluated patients followed at a tertiary university center. A total of 224 patients were included, with a median follow-up period of 9 years. The mean age at HBV diagnosis was 38.71 ± 14.19 years, predominantly males (66.1%). The cumulative incidence of HCC at 3, 5, and 7 years was 0.993%, 2.70%, and 5.25%, respectively, being related in the univariate logistic regression analysis to male sex (p = 0.0461), older age (p = 0.0001), cirrhosis at HBV diagnosis (p < 0.0001), and higher values of PAGE-B and mPAGE-B scores (p = 0.0002 and p < 0.0001, respectively). Older age, male sex, and cirrhosis at HBV diagnosis were independently associated with HCC occurrence. The AUROCs of PAGE-B and mPAGE-B were 0.7906 and 0.7904, respectively, with no differences between them (p = 0.9767). In conclusion, both PAGE-B and mPAGE-B showed a correct prediction of HCC above 70% in this cohort.     

Avian Reovirus σB Interacts with Caveolin-1 in Lipid Rafts during Dynamin-Dependent Caveolae-Mediated Endocytosis

Caveolin-1 (Cav-1) is the basic component of caveolae, a specialized form of lipid raft that plays an essential role in endocytic viral entry. However, the evidence of direct involvement of caveolae and Cav-1 in avian reovirus (ARV) entry remains insufficient. In this study, the membrane lipid rafts were isolated as detergent-resistant microdomains (DRMs) by sucrose gradient centrifugation, and the capsid protein σB of ARV was found to associate with Cav-1 in DRMs fractions. Additionally, the interaction between ARV σB protein and Cav-1 was demonstrated by immunofluorescence co-localization and co-immunoprecipitation assays. Furthermore, we found that the internalization of ARV is sensitive to caveolae and dynamin inhibitors, while it is insensitive to clathrin inhibitors. In conclusion, these results indicate that the ARV σB protein interacts with Cav-1 during dynamin-dependent caveolae-mediated endocytosis for the entry of ARV.     

Impact of Hepatitis B Virus Infection,Non-alcoholic Fatty Liver Disease,and Hepatitis C Virus Co-infection on Liver-Related Death among People Tested for Hepatitis B Virus in British Columbia: Results from a Large Longitudinal Population-Based Cohort Study

Data on the contribution of hepatitis B virus (HBV) infection and related comorbidities to liver-related mortality in Canada are limited. We assessed the concurrent impact of HBV infection, non-alcoholic fatty liver disease (NAFLD), and hepatitis C virus (HCV) coinfection on liver-related deaths in British Columbia (BC), Canada. We used data from the BC Hepatitis Testers Cohort (BC-HTC). We used Fine–Gray multivariable sub-distributional hazards models to assess the effect of HBV, NAFLD, and HCV coinfection on liver-related mortality, while adjusting for confounders and competing mortality risks. The liver-related mortality rate was higher among people with HBV infection than those without (2.57 per 1000 PYs (95%CI: 2.46, 2.69) vs. 0.62 per 1000 PYs (95%CI: 0.61, 0.64), respectively). Compared with the HBV negative groups, HBV infection was associated with increased liver-related mortality risk in almost all of the subgroups: HBV mono-infection (adjusted subdistribution hazards ratio (asHR) of 3.35, 95% CI 3.16, 3.55), NAFLD with HBV infection, (asHR 12.5, 95% CI 7.08, 22.07), and HBV/HCV coinfection (asHR 8.4, 95% CI 7.62, 9.26). HBV infection is associated with a higher risk of liver-related mortality, and has a greater relative impact on people with NAFLD and those with HCV coinfection. The diagnosis and treatment of viral and fatty liver disease are required to mitigate liver-related morbidity and mortality.     

Re-Entry Evaluation of Chinese Blood Donors with Unconfirmed Hepatitis B Screening Results

The hepatitis B virus (HBV) remains a high priority for Chinese blood banks due to the high prevalence of infection. HBV blood safety has been significantly improved by the implementation of highly sensitive and specific serological and molecular HBV screening assays. The multiplication of viral markers tested and the ever-increasing analytical sensitivity of the tests can make the interpretation of the results difficult. False-positive or indeterminate results may lead to permanent donor deferrals and conflicts between donors and blood banks. To avoid blood shortages, blood services aim to limit unnecessary donor losses by developing procedures for the re-entry of donors temporarily deferred due to an unconfirmed HBV reactivity. The development of such procedures based on donor follow-up and HBV confirmation remains limited. A review of the scarce data available revealed considerable heterogeneity in testing methods and re-entry algorithms, limited validation studies, and a lack of accurate assessment of the residual infectious risk potentially associated with donor re-entry. In conclusion, systematic and widely validated confirmatory testing and prolonged follow-up are essential for safe re-entry of temporary deferred donors. Standardization of HBV testing methods and the establishment of dedicated expert laboratories are needed because of the complexity of HBV infection in blood donors.     

Host Cell Entry and Neutralization Sensitivity of SARS-CoV-2 Lineages B.1.620 and R.1

The spike (S) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) facilitates viral entry into host cells and is the key target for neutralizing antibodies. The SARS-CoV-2 lineage B.1.620 carries fifteen mutations in the S protein and is spread in Africa, the US and Europe, while lineage R.1 harbors four mutations in S and infections were observed in several countries, particularly Japan and the US. However, the impact of the mutations in B.1.620 and R.1 S proteins on antibody-mediated neutralization and host cell entry are largely unknown. Here, we report that these mutations are compatible with robust ACE2 binding and entry into cell lines, and they markedly reduce neutralization by vaccine-induced antibodies. Our results reveal evasion of neutralizing antibodies by B.1.620 and R.1, which might have contributed to the spread of these lineages.