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BackgroundCOVID-19 epidemic has lasted for nearly 3 years, and revolutionized social life. In the study, in-depth interviews were conducted with Chinese undergraduate students to explore their understanding and experience of meaning in life. Meaning of life is interpreted from four aspects: life goals, life value, life enthusiasm, and life freedom. These four aspects are independent yet interrelated. Based on the free grasp of life, individuals explore and pursue the true meaning of life goals, acquire life value in evaluating the completion of life goals, and subsequently experience enthusiasm for life. Life enthusiasm and the perception of life value can help individuals to further understand and possess their meaning of life.Materials and methodsThe present study adopts the qualitative method to understand the experience of meaning in life among Chinese undergraduate students. Semi-structured interviews were conducted, and six people participated the study. The Grounded Theory was adopted to analyze the qualitative data.Results(1) Chinese undergraduates had clear life goals and obtained a certain sense of achievement and satisfaction when striving for these goals. (2) The life value of Chinese undergraduates was mainly to their families, but there was also a willingness to make due contributions to the country and society. (3) Chinese undergraduates’ feelings about life were polarized, but they all expressed the view of “living in the moment and cherishing the present.” (4) Chinese undergraduate students see life freedom as freedom of choice and generally believed that COVID-19 did not restrict their lives very much. (5) Chinese undergraduate students gained a deeper understanding of meaning in life after this major public health emergency.

Lesion mimic mutants (LMMs) are plants that spontaneously form lesions without pathogen infection or external stimulus and exhibit resistance to pathogens. Here, a rice LMM was created by ethyl methane sulfonate mutagenesis, named as hpil (hydrogen peroxide induced lesion). Diaminobenzidine and trypan blue staining showed that large amounts of H2O2 were produced and cell death was occurred at and around the parts of lesion mimic in the rice leaves. The phenotype of hpil is controlled by a single recessive gene, localized at a 2 Mb interval on chromosome 2. The data suggested that hpil is a novel LMM with enhanced bacterial and fungal disease resistance, and multiple pathogenesis-related proteins (PRs) were up-regulated. The proteomes of leaves at three positions (different degrees of lesion mimic severity) were characterized in hpil compared with its wild type plant. Differentially expressed proteins were detected by two dimensional difference gel electrophoresis and 274 proteins were identified by MALDI TOF/TOF™. These proteins were related to metabolic process, cellular process and response to stimulus, with mostly down-regulated in hpil leaves. Many of these proteins were related to the Calvin cycle, photosynthetic electron transport chain, glycolysis/gluconeogenesis and phosphonates pathways. Some resistance-related proteins including 14-3-3 proteins, OsPR10 and antioxidases such as peroxidase, superoxide dismutase and ascorbate peroxidase were up-regulated in leaves with lesion mimic. These results provide the foundation for cloning of the target gene and shed light on the mechanism involved in autoimmunity of rice.

This paper constructs an economic dispatch model of an integrated energy system including grid, wind power, photovoltaic and energy storage devices based on combined cooling, heating and power system, and optimizes the dispatch model based on improved krill swarm optimization algorithm with the system integrated cost as the objective function, taking into account the electric power balance constraint, cooling and heating load balance constraint and each micro-source output constraint. The simulation results show that the improved krill swarm algorithm can reduce the daily integrated cost by $124.1 and $50.3 respectively, which can save 9.5% and 3.9% of the daily integrated cost compared with the conventional krill swarm algorithm and the artificial bee colony algorithm. The constructed integrated energy system model can effectively improve the energy utilization and economic efficiency of the system.

Introduction and objectives: Pulmonary vein isolation (PVI) technique has become the cornerstone of atrial fibrillation (AF) catheter ablation. The objective of this study was to assess the efficacy and safety of extended antrum ablation based on electrophysiological substrate mapping plus PVI in AF patients who underwent cryoballoon ablation. Methods: In this observational study, a total of 121 paroxysmal AF patients and 80 persistent AF patients who did not achieve the procedure endpoint after cryoballoon ablation received extra extended antrum ablation (EAA) based on electrophysiological substrate mapping via radiofrequency ablation (EAA group). As a control group (PVI group), among paroxysmal AF and persistent AF patients, we conducted a propensity score-matched cohort, in whom only PVI was completed. Results: The average follow-up time was 15.27±7.34 months. Compared with PVI group, paroxysmal AF patients in the EAA group had a significantly higher rate of AF-free survival (90.1% vs. 80.2%, p=0.027) and AF, atrial flutter, or atrial tachycardia (AFLAT) -free rate survival (89.3% vs. 79.3%, p=0.031). Persistent AF patients in the EAA group also had a significantly higher rate of AF-free survival (90.0% vs. 75.0%, p=0.016) and AFLAT-free survival (88.8% vs. 75.0%, p=0.029) than PVI group. Complication rates did not significantly differ between both groups, in either paroxysmal AF or persistent AF patients. Conclusion: Our findings demonstrate that extra extended antrum ablation based on electrophysiological substrate mapping is effective and safe. Moreover, the strategy can improve the outcome of AF cryoablation. Resumo: Introdução e objetivos: A técnica de isolamento das veias pulmonares (IVP) tornou-se a pedra angular da ablação por cateter da fibrilhação auricular (FA). O objetivo deste estudo consistiu em avaliar a eficácia e a segurança da ablação antral alargada com base no mapeamento do substrato eletrofisiológico, para lá do IVP em doentes com FA, submetidos a crioablação. Métodos: Neste estudo observacional, 121 doentes com FA paroxística e 80 doentes com FA persistente que não alcançaram o objetivo do procedimento após a crioablação foram submetidos a ablação antral alargada com base no mapeamento do substrato eletrofisiológico, através de ablação por radiofrequência (grupo de Ablação Antral Alargada, grupo AAA). Como grupo controlo (grupo do Isolamento das Veias Pulmonares, grupo IVP), em doentes com FA paroxística e com FA persistente, realizámos um score de propensão agrupado, no qual só foi efetuado o IVP. Resultados: O tempo médio de seguimento foi 15,27±7,34 meses. Quando comparados com o grupo IVP, os doentes com FA paroxística no grupo AAA apresentaram uma taxa significativamente mais elevada de sobrevivência livre de FA (90,1% versus 80,2%, p=0,027) e de sobrevivência livre de AFLAT (FA, flutter auricular ou taquicardia auricular) (89,3% versus 79,3%, p=0,031). Os doentes com FA persistente no grupo AAA também apresentaram uma taxa significativamente mais elevada de sobrevivência livre de FA (90,0% versus 75,0%, p=0,016) e de sobrevivência livre de AFLAT (88,8% versus 75,0%, p=0,29) do que no grupo de IVP. As taxas de complicações não diferiram significativamente entre dois grupos, tanto nos doentes com FA paroxística como nos com FA persistente. Conclusão: Os nossos resultados demonstraram que a ablação antral alargada com base no mapeamento de substrato eletrofisiológico é eficaz e segura. Além disso, a estratégia pode melhorar os resultados da FA por crioablação.