Optical transitions between Landau levels: AA-stacked bilayer graphene

The low-frequency optical excitations of AA-stacked bilayer graphene are investigated by the tight-binding model. Two groups of asymmetric LLs lead to two kinds of absorption peaks resulting from only intragroup excitations. Each absorption peak obeys a single selection rule similar to that of monolayer graphene. The excitation channel of each peak is changed as the field strength approaches a critical strength. This alteration of the excitation channel is strongly related to the setting of the Fermi level. The peculiar optical properties can be attributed to the characteristics of the LL wave functions of the two LL groups. A detailed comparison of optical properties between AA-stacked and AB-stacked bilayer graphenes is also offered. The compared results demonstrate that the optical properties are strongly dominated by the stacking symmetry. Furthermore, the presented results may be used to discriminate AABG from MG, which can be hardly done by STM

The Impact of Individual Characteristics, Personality Traits, Perceived Risk on Young People's Intention to Participate in Overseas Working Holiday

AbstractThis paper analyzes whether individual characteristics, personality traits, and perceived risk will affect young people's intention to participate in overseas working holiday, and taking the three countries of Australia, the United States, and the United Kingdom as examples. The sample consists of young people and students at numerous universities and colleges, with ages ranging from 18 to 31. A total of 350 questionnaires were issued, and 204 valid questionnaires were recovered, with a return rate of 58.2%. Multiple regression was used to test hypotheses. The research results indicate that the factors influencing young people's intention to take working holiday in different countries were not entirely the same. It is found that age, work experience, neuroticism, extroversion, openness to experience, agreeableness, environmental and social risk, and agent and workplace risk may influence intention to participate in overseas working holiday. The research implications and recommendations are also presented

Association of Antihistamine Use with Increased Risk of Esophageal Squamous Cell Carcinoma: A Nationwide, Long-Term Follow-Up Study Using Propensity Score Matching

Esophageal cancer is a common and aggressive cancer, with a five-year survival rate of approximately 20%. Therefore, identifying safe and effective medications that can reduce the risk of esophageal cancer is of great importance. Objective: To examine the association between H1-antihistamines (AHs) use and the incidence of esophageal squamous cell carcinoma (ESCC) in a head-to-head propensity score matching (PSM) comparative study. Design: Retrospective cohort study. Setting: Nationwide population-based study in Taiwan. Participants: 1289,526 adults from the National Health Insurance Research Database from 2008 to 2018. Exposures: AH use. Main Outcomes and Measures: Incidence rates (IRs), incidence rate ratios (IRRs), and adjusted hazard ratios (aHRs) of ESCC in AH users compared with nonusers. Results: AH users had a significantly higher IR of ESCC than nonusers (1.47 vs. 1.36 per 100,000 person-years). The IRR (95% CI) for ESCC was 1.18 (1.08–1.28) in AH users compared with nonusers. After adjustment for age, sex, income levels, urbanization, cigarettes smoking, alcoholic related diseases, comorbidities, medication use, and Charlson Comorbidity Index scores, the aHR (95% CI) for ESCC was 1.22 (1.12–1.33) in AH users compared with nonusers. A dose–response relationship was also observed, with aHRs for AH use at 28–182, 183–488, 489–1043, and >1043 cumulative defined daily doses (cDDDs) of 1.12, 1.20, 1.25, and 1.37, respectively, compared with <28 cDDDs. Conclusions and Relevance: Our study found a significant association between AH use and the increased risk of ESCC, with a dose–response relationship. This study suggests that AH use may increase the risk of ESCC, especially at high doses, and highlights the importance of caution when prescribing AHs

In Vivo Validation of Diffuse Optical Imaging with a Dual-Direction Measuring Module of Parallel-Plate Architecture for Breast Tumor Detection

We demonstrate a working prototype of an optical breast imaging system involving parallel-plate architecture and a dual-direction scanning scheme designed in combination with a mammography machine; this system was validated in a pilot study to demonstrate its application in imaging healthy and malignant breasts in a clinical environment. The components and modules of the self-developed imaging system are demonstrated and explained, including its measuring architecture, scanning mechanism, and system calibration, and the reconstruction algorithm is presented. Additionally, the evaluation of feature indices that succinctly demonstrate the corresponding transmission measurements may provide insight into the existence of malignant tissue. Moreover, five cases are presented including one subject without disease (a control measure), one benign case, one suspected case, one invasive ductal carcinoma, and one positive case without follow-up treatment. A region-of-interest analysis demonstrated significant differences in absorption between healthy and malignant breasts, revealing the average contrast between the abnormalities and background tissue to exceed 1.4. Except for ringing artifacts, the average scattering property of the structure densities was 0.65&ndash;0.85 mm&minus;1

The Role of Sirtuin 1 in Palmitic Acid-Induced Endoplasmic Reticulum Stress in Cardiac Myoblasts

Background: Lipotoxicity causes endoplasmic reticulum (ER) stress, leading to cell apoptosis. Sirtuin 1 (Sirt1) regulates gene transcription and cellular metabolism. In this study, we investigated the role of Sirt1 in palmitate-induced ER stress. Methods: Both H9c2 myoblasts and heart-specific Sirt1 knockout mice fed a palmitate-enriched high-fat diet were used. Results: The high-fat diet induced C/EBP homologous protein (CHOP) and activating transcription factor 4 (ATF4) expression in both Sirt1 knockout mice and controls. The Sirt1 knockout mice showed higher CHOP and ATF4 expression compared to those in the control. Palmitic acid (PA) induced ATF4 and CHOP expression in H9c2 cells. PA-treated H9c2 cells showed decreased cytosolic NAD+/NADH alongside reduced Sirt1&prime;s activity. The H9c2 cells showed increased ATF4 and CHOP expression when transfected with plasmid encoding dominant negative mutant Sirt1. Sirt1 activator SRT1720 did not affect CHOP and ATF4 expression. Although SRT1720 enhanced the nuclear translocation of ATF4, the extent of the binding of ATF4 to the CHOP promoter did not increase in PA treated-H9c2 cells. Conclusion: PA-induced ER stress is mediated through the upregulation of ATF4 and CHOP. Cytosolic NAD+ concentration is diminished by PA-induced ER stress, leading to decreased Sirt1 activity. The Sirt1 activator SRT1720 promotes the nuclear translocation of ATF4 in PA-treated H9c2 cells