Optimal mean-variance reinsurance with common shock dependence

We consider the optimal proportional reinsurance problem for an insurer with two dependent classes of insurance business, where the two claim number processes are correlated through a common shock component. Using the technique of stochastic linear–quadratic control theory and the Hamilton–Jacobi–Bellman equation, we derive the explicit expressions for the optimal reinsurance strategies and value function, and present the verification theorem within the framework of the viscosity solution. Furthermore, we extend the results in the linear–quadratic setting to the mean–variance problem, and obtain an efficient strategy and frontier. Some numerical examples are given to show the impact of model parameters on the efficient frontier. doi:10.1017/S144618111600016

Emotion, analytic thinking and susceptibility to misinformation during the COVID-19 outbreak

Misinformation has become prevalent since the beginning of the COVID-19 pandemic. To understand why people believe and share misinformation, we conducted a nationwide survey during the COVID-19 outbreak in China. We found the indirect effects of COVID-19 risk on people&#39;s information accuracy judgment and associated information sharing intention through people&#39;s emotional states. People faced with a higher level of COVID-19 risk (measured by a 7-day moving average of daily new deaths or new cases) experienced weaker positive and stronger negative emotions, and heightened emotionality (both the positive and negative emotions) was associated with increased belief in and greater likelihood to share the COVID-19 information regardless of veracity. We also found that only the negative emotion mediated the relation between the COVID-19 risk and the truth discernment regarding accuracy judgment. However, the mediating effect of negative emotion disappeared among people with high analytic thinking ability. These findings suggest that the analytic thinking ability could moderate the destructive relationship between negative emotion and accuracy discernment. Based on a large sample, our findings provide actionable insights for the policymakers to respond to the spread of misinformation appropriately and promptly during the pandemic.</p

Mechanism of Hydrogen Absorption in 1:7 Sm-Co Phase With Higher Fe Content

Hydrogen absorption (HA) capacity of Sm(CobalFexCu0.053Zr0.02)(7.84) (x = 0.2, 0.3, 0.4, 0.5) as-cast alloys was improved through increasing Fe content and its mechanism was symmetrically analyzed. X-ray diffraction analysis indicates that the main phase of all as-cast alloys was 1: 7 phase. Due to lower electronegativity of Fe than that of Co, activation energy of chemical adsorption for 1: 7 phase was reduced with increasing Fe content. Due to larger atomic radius of Fe than that of Co, lattice parameters and lattice gaps of 1: 7 phases were enlarged with increasing Fe content, and diffusion barrier of H atoms was lowered resulting from increasing lattice parameters and sizes of lattice gaps. These all strengthened the HA capacity of 1: 7 phase. Two principles are mentioned to provide theoretical guidance for strengthening HA capacity by adding other elements

Table1_Detection of ROS1 gene fusions using next-generation sequencing for patients with malignancy in China.docx

Objective: This study aimed to identify ROS1 fusion partners in Chinese patients with solid tumors.Methods: Next-generation sequencing (NGS) analysis was used to detect ROS1 rearrangement in 45,438 Chinese patients with solid tumors between 2015 and 2020, and the clinical characteristics and genetic features of gene fusion were evaluated. H&E staining of the excised tumor tissues was conducted. Samples with a tumor cell content ≥ 20% were included for subsequent DNA extraction and sequencing analysis.Results: A total of 92 patients with ROS1 rearrangements were identified using next-generation sequencing, and the most common histological type lung cancer. From the 92 ROS1 fusion cases, 24 ROS1 fusion partners had been identified, including 14 novel partners and 10 reported partners. Of these, CD74, EZR, SDC4, and TPM3 were the four most frequently occurring partners. Fourteen novel ROS1 fusion partners were detected in 16 patients, including DCBLD1-ROS1, FRK-ROS1, and VGLL2-ROS1. In many patients, the ROS1 breakpoint was located between exons 32 and 34.Conclusion: This study describes 14 novel ROS1 fusion partners based on the largest ROS1 fusion cohort, and the ROS1 breakpoint was mostly located between exons 32 and 34. Additionally, next-generation sequencing is an optional method for identifying novel ROS1 fusions.</p

Organocatalytic Discrimination of Non-Directing Aryl and Heteroaryl Groups: Enantioselective Synthesis of Bioactive Indole-Containing Triarylmethanes

Despite the enormous developments of asymmetric catalysis, the basis for asymmetric induction is largely limited to spatial interaction between substrate and catalyst. Consequently, asymmetric discrimination between two sterically similar groups remains a challenge. This is particularly formidable for enantiodifferentiation between aryl and heteroaryl groups without a directing group or electronic manipulation. Here we address this challenge by a robust organocatalytic system leading to excellent enantioselection between aryl and heteroaryl groups. With the versatile 2-indole imine methide as platform, an excellent combination of a superb chiral phosphoric acid and the optimal hydride source provided efficient access to a range of highly enantioenriched indole-containing triarylmethanes. Control experiments and kinetic studies provided important insights into the mechanism. DFT calculations also indicated that, while hydrogen bonding is important for activation, the key interaction for discrimination of the two aryl groups is mainly π-π stacking. Preliminary biological studies also demonstrated the great potential of these triarylmethanes for anticancer and antiviral drug development

Gene silencing of Toll-like receptor 2 inhibits proliferation of human liver cancer cells and secretion of inflammatory cytokines.

BACKGROUND: Toll-like receptors (TLRs) are key factors in the innate immune system and initiate the inflammatory response to foreign pathogens such as bacteria, fungi and viruses. In the microenvironment of tumorigenesis, TLRs can promote inflammation and cell survival. Toll-like receptor 2/6 (TLR2/6) signaling in tumor cells is regarded as one of the mechanisms of chronic inflammation but it can also mediate tumor cell immune escape and tumor progression. However, the expression of TLR2 and its biological function in the development and progression of hepatocarcinoma have not been investigated. This study aimed to determine the expression of TLRs 1-10 in the established human hepatocellular carcinoma cell line BLE-7402, to investigate the biological effect of TLR2 on cell growth and survival. METHODS: TLR expression in BLE-7402 cells was assayed by RT-PCR, real-time PCR and flow cytometry (FCM). To further investigate the function of TLR2 in hepatocarcinoma growth, BLE-7402 cells were transfected with recombinant plasmids expressing one of three forms of TLR2 siRNA (sh-TLR2 RNAi(A, B and C)). TLR2 knockdown was confirmed using RT-PCR, real-time PCR and fluorescence microscopy. Tumor cell proliferation was monitored by MTT assay and secreted cytokines in the supernatant of transfected cells were measured by bead-based FCM, the function of TLR2 siRNA was also investigated in vivo. RESULTS: The BLE-7402 cell line expressed TLRs 2 to 10 at both mRNA and protein levels. TLR2 was the most highly expressed TLR. While all the three siRNAs inhibited TLR2 mRNA and protein expression, sh-TLR2 RNAi(B) had the strongest knockdown effect. TLR2 knockdown with sh-TLR2 RNAi(B) reduced cell proliferation. Furthermore, secretion of IL-6 and IL-8 was also reduced. The result showed a drastic reduction in tumor volume in mice treated with sh-TLR2 RNAi(B). DISCUSSION: These results suggest that TLR2 knockdown inhibit proliferation of cultured hepatocarcinoma cells and decrease the secretion of cytokines. It is suggested that TLR2 silencing may worth further investigations for siRNA based gene therapy in treatment of hepatocarcinoma

Effects of Fortunella margarita fruit extract on metabolic disorders in high-fat diet-induced obese C57BL/6 mice.

INTRODUCTION: Obesity is a nutritional disorder associated with many health problems such as dyslipidemia, type 2 diabetes and cardiovascular diseases. In the present study, we investigated the anti-metabolic disorder effects of kumquat (Fortunella margarita Swingle) fruit extract (FME) on high-fat diet-induced C57BL/6 obese mice. METHODS: The kumquat fruit was extracted with ethanol and the main flavonoids of this extract were analyzed by HPLC. For the preventive experiment, female C57BL/6 mice were fed with a normal diet (Chow), high-fat diet (HF), and high-fat diet with 1% (w/w) extract of kumquat (HF+FME) for 8 weeks. For the therapeutic experiment, female C57BL/6 mice were fed with high-fat diet for 3 months to induce obesity. Then the obese mice were divided into two groups randomly, and fed with HF or HF+FME for another 2 weeks. Body weight and daily food intake amounts were recorded. Fasting blood glucose, glucose tolerance test, insulin tolerance test, serum and liver lipid levels were assayed and the white adipose tissues were imaged. The gene expression in mice liver and brown adipose tissues were analyzed with a quantitative PCR assay. RESULTS: In the preventive treatment, FME controlled the body weight gain and the size of white adipocytes, lowered the fasting blood glucose, serum total cholesterol (TC), serum low density lipoprotein cholesterol (LDL-c) levels as well as liver lipid contents in high-fat diet-fed C57BL/6 mice. In the therapeutic treatment, FME decreased the serum triglyceride (TG), serum TC, serum LDL-c, fasting blood glucose levels and liver lipid contents, improved glucose tolerance and insulin tolerance. Compared with the HF group, FME significantly increased the mRNA expression of PPARα and its target genes. CONCLUSION: Our study suggests that FME may be a potential dietary supplement for preventing and ameliorating the obesity and obesity-related metabolic disturbances