Spectral inclusion property for a class of block operator matrices

The numerical range and the quadratic numerical range is used to study the spectrum of a class of block operator matrices. We show that the approximate point spectrum is contained in the closure of the quadratic numerical range. In particular, the spectral enclosures yield a spectral gap. It is shown that these spectral bounds are tighter than classical numerical range bounds

The Regulation of Leptin, Leptin Receptor and Pro-opiomelanocortin Expression by N-3 PUFAs in Diet-Induced Obese Mice Is Not Related to the Methylation of Their Promoters

<p>Abstract</p> <p>Background</p> <p>The expression of leptin is increased in obesity and inhibited by n-3 polyunsaturated fatty acids (n-3 PUFAs), but the underlying molecular mechanisms have not been firmly established.</p> <p>Methods</p> <p>In this study, we investigated the effects of dietary n-3 PUFAs on the methylation of CpG islands in the promoter regions of the leptin, leptin-R and POMC genes, as well as the effects of n-3 PUFA status in early life on the modification of the promoters of these three genes. Male C57 BL/6J mice were fed a high-fat diet with one of four different fat types: sunflower oil (n-3 PUFA deficient), soy oil, fish oil, or a mixture of soy and fish oil (soy:fish oil = 1:1). Two low-fat diets with sunflower oil or soy oil served as controls. Female mice were fed two breeding diets, sunflower oil or a mixture of soy and fish oil (soy:fish oil = 1:1), during pregnancy and lactation to breed new pups.</p> <p>Results</p> <p>Compared to mice fed the control diets, the expression of leptin in fat tissue and leptin-R and POMC in the hypothalamus was higher in the diet-induced obesity (DIO) mice, and the n-3 PUFAs in the diets reversed these elevated expression levels. The mean methylation levels of CpG sites in the promoter regions of the leptin and POMC genes showed no difference between the DIO and the control diet groups nor between the n-3 PUFA-containing and -deficient diet groups. For the CpG sites in the promoter regions of leptin-R, no methylation was found in any of the DIO or control groups. Feeding mice with the n-3 PUFA diet during pregnancy and lactation did not affect CpG methylation in the leptin or POMC promoters.</p> <p>Conclusions</p> <p>Our findings indicate that promoter DNA methylation may not be related to the expression of leptin, leptin-R or its related hypothalamic satiety regulator POMC.</p

Analysis of Demographic Characteristics and Psychological Factors of Opioid Addicts in Zhengzhou Area

Objective: To explore the demographic characteristics and psychological factors of patients with opioid addiction. Methods: A random number method was used to select 200 opioid-addicted patients admitted to the 7th People’s Hospital of Zhengzhou from January 2019 to February 2020. Demographic characteristics and psychosocial factors were analyzed. Result: The proportion of opioid addicts aged 21 ~ 30 was the highest; the proportion of men was significantly higher; the proportion of people who is between jobs/unemployed is the highest; the proportion of junior middle school was the highest, and the proportion of unmarried was relatively high; the proportion of opioid addicts with ignorance/curiosity for the cause of first addiction was the highest; the use of suction is snorting, accounting for the highest proportion. According to the analysis of relevant social and psychological factors, the proportion of single parent family group is the highest, the proportion of parent tension is the highest, and the proportion of bad life coping style is relatively high. At the same time, dependent psychology occupies the highest proportion in psychological factors of relapse patients. Conclusion: By analyzing the demographic characteristics of opioid addicts and the psychosocial factors of their addiction, we can strengthen prevention and management for specific groups to reduce the new addition and relapse of opioid addicts

Toward Electrically Pumped Organic Lasers: A Review and Outlook on Material Developments and Resonator Architectures

Organic lasers have undergone decades of development. A myriad of materials with excellent optical gain properties, including small molecules, dendrimers, and polymers, have been demonstrated. Various resonator geometries have also been applied. While sharing the advantages of the solution processability and mechanical flexibility features of organic materials, organic optical gain media also offer interesting optical properties, such as emission tunability through chemical functionalization and inherent large optical gain coefficients. They offer prospects for different applications in the fields of bioimaging, medicine, chemo‐ and biosensing, anticounterfeit applications, or displays. However, the realization of electrically pumped organic lasers still remains a challenge due to the inherent drawbacks of organic semiconductors, e.g., modest carrier mobility, long‐lived excited‐state absorption, and extra losses which originate in the device (e.g., absorption from metal electrodes). Herein, the past developments of organic lasers are discussed, highlighting the importance of materials and cavities with regard to the goal of electrically pumped organic lasers. The latest progress and the possible ways to address the challenge are discussed