An interpolation matched interface and boundary method for elliptic interface problems

AbstractAn interpolation matched interface and boundary (IMIB) method with second-order accuracy is developed for elliptic interface problems on Cartesian grids, based on original MIB method proposed by Zhou et al. [Y. Zhou, G. Wei, On the fictious-domain and interpolation formulations of the matched interface and boundary method, J. Comput. Phys. 219 (2006) 228–246]. Explicit and symmetric finite difference formulas at irregular grid points are derived by virtue of the level set function. The difference scheme using IMIB method is shown to satisfy the discrete maximum principle for a certain class of problems. Rigorous error analyses are given for the IMIB method applied to one-dimensional (1D) problems with piecewise constant coefficients and two-dimensional (2D) problems with singular sources. Comparison functions are constructed to obtain a sharp error bound for 1D approximate solutions. Furthermore, we compare the ghost fluid method (GFM), immersed interface method (IIM), MIB and IMIB methods for 1D problems. Finally, numerical examples are provided to show the efficiency and robustness of the proposed method

EFFECT OF DUAL-TRACK INTERACTIVE NURSING INTERVENTION MODEL ON ANXIETY AND DEPRESSION IN PATIENTS WITH CORONARY HEART DISEASE

Background: Elderly patients with coronary heart disease often suffer adverse psychological reactions, such as anxiety and depression. The dual-track interactive nursing model is a nursing intervention aimed to provide specific and community nursing. For patients with chronic diseases, this model can improve the patients’ self-management and rehabilitation. The effect of this model on the mental health of patients with chronic diseases has been unanimously recognized by researchers. In this study, a dual-track interactive nursing model intervention was conducted on the anxiety and depression in elderly patients with coronary heart disease to verify the psychological effect of the model. Subjects and methods: From June 2018 to June 2019, 136 elderly patients with coronary heart disease (mean age of 63.5±8.26 years) from three communities in Changsha, Hunan Province, China were selected as subjects. A total of 53 and 50 patients were identified in the intervention and the control groups, respectively. The control group underwent routine longitudinal referral, whereas the intervention group was subjected to a two-track interactive nursing model intervention. The Short Form-36 Health Survey (SF-36) and related questionnaires were used to monitor and compare the two groups before and after the intervention and employed for scoring and comparative analysis. Results: After the intervention, the mental health scores of the intervention group in total score, somatization, obsessive–compulsive symptoms, interpersonal sensitivity, depression, anxiety, hostility, and paranoia are significantly lower than those of the control group (P<0.05). The intervention group has scored significantly higher in coping style but significantly lower in negative coping than the control group (P<0.05). Conclusions: The application of the dual-track interactive nursing model intervention in the management of patients with coronary heart disease can improve the self-management and the mental health of patients with coronary heart disease

A study of association between expression of hOGG1, VDAC1, HK-2 and cervical carcinoma

<p>Abstract</p> <p>Background</p> <p>Human 8-oguanine glycosylase 1(hOGG1), voltage-dependent anion channel 1(VDAC1), hexokinase 2(HK-2), represented the process of oxidative DNA damage, cell apoptosis and glycolysis, respectively. This study aims to explore the association between expression of hOGG1, VDAC1, HK-2 and cervical carcinoma.</p> <p>Methods</p> <p>A case-control study was conducted. 65 cervical biopsy samples consist of 20 control and 45 cases. The expression of hOGG1, VDAC1 and HK-2 were examined with immunohistochemistry(IHC), immunolabeling was evaluated with stereological cell counts.</p> <p>Results</p> <p>The data showed that the positive proportion of hOGG1 and HK-2 in the case group was higher than that of the control group (P < 0.05). Further, there was an increasing trend for the positive proportion and expression degree of hOGG1 and HK-2 from Control, Mild cervical carcinoma (MCC), Intermediate cervical carcinoma(ICC) to Severe cervical carcinoma(SCC) in order (P < 0.05). To VDAC1, the significant result was not obtained.</p> <p>Conclusions</p> <p>The results suggested that there was a close association between expression of hOGG1, HK-2 and cervical cancer. hOGG1 and HK-2 might play a key role at the early stage of cervical cancer, and the findings of hOGG1 and HK-2 should be considered as a significant biomarker at the early stage of cervical cancer.</p

Contamination and mobile colistin resistance gene analysis for Salmonella isolated from retail chickens in Ji'nan

ObjectiveTo investigate the contamination of Salmonella in retail chickens in Ji’nan city from 2020 to 2021， and to explore the prevalence of the mobile colistin resistance gene （mcr） among these Salmonella isolates.MethodsFrom December 2020 to November 2021， 260 retail chicken samples were collected in Ji’nan City， and Salmonella was isolated and confirmed according to GB 4789.4—2016 “National food standard - Food microbiological examination： Salmonella”. Serotype identification and mcr gene screening were performed for all Salmonella isolates by polymerase chain reaction （PCR）. The drug resistance of mcr gene-positive strains was tested by micro-broth dilution method.ResultsA total of 61 in 260 retail chicken samples were positive for Salmonella detection with the contamination rate of 23.46% （61/260）. The highest contamination rate was 53.33% （32/60） for samples collected in autumn. One hundred and three Salmonella strains were isolated， 56 of which were Salmonella Enteritidis， accounting for 54.37% （56/103）. Two Salmonella Indiana， isolated from two separate chicken wing samples collected from different regions， were positive for mcr-1 gene， with a positive rate of 1.94% （2/103）. Antimicrobial susceptibility testing revealed that both of the two mcr-1-harboring Salmonella Indiana were multi-drug resistant， and one of them was concurrently resistant to all 12 categories of tested drugs， including carbapenems and polymyxins.ConclusionThere was a certain degree of Salmonella contamination in retail chickens in Jinan from 2020 to 2021， and the contamination rate of the samples collected in autumn was higher than in any other seasons. Salmonella Enteritidis was the predominant serotype. It should be of concern that a Salmonella isolate carried mcr-1 gene with severe multidrug resistance to both colistin and carbapenems， indicating that the surveillance for Salmonella in the whole chain of chicken production should be strengthened continuously， to provide important basic data for the prevention and control of foodborne diseases

Template Synthesis of Carbon Nanofibers Containing Linear Mesocage Arrays

Carbon nanofibers containing linear mesocage arrays were prepared via evaporation induced self-assembly method within AAO template with an average channel diameter of about 25 nm. The TEM results show that the mesocages have an elongated shape in the transversal direction. The results of N2 adsorption–desorption analysis indicate that the sample possesses a cage-like mesoporous structure and the average mesopore size of the sample is about 18 nm