The Pontryagin Class for Pre-Courant Algebroids

In this paper, we show that the Jacobiator $J$ of a pre-Courant algebroid is closed naturally. The corresponding equivalence class $[J^\flat]$ is defined as the Pontryagin class, which is the obstruction of a pre-Courant algebroid to be deformed into a Courant algebroid. We construct a Leibniz 2-algebra and a Lie 2-algebra associated to a pre-Courant algebroid and prove that these algebraic structures are isomorphic under deformations. Finally, we introduce the twisted action of a Lie algebra on a manifold to give more examples of pre-Courant algebroids, which include the Cartan geometry.Comment: 26 page

Tunable hysteresis effect for perovskite solar cells

Perovskite solar cells (PSCs) usually suffer from a hysteresis effect in current–voltage measurements, which leads to an inaccurate estimation of the device e fficiency. Although ion migration, charge trapping/ detrapping, and accumulation have been proposed as a b asis for the hysteresis, the origin of the hysteresis has not been apparently unraveled. Herein we reporte d a tunable hysteresis effect based uniquely on open- circuit voltage variations in printable mesos copic PSCs with a simplified triple-layer TiO 2 /ZrO 2 /carbon architecture. The electrons are collected by the compact TiO 2 /mesoporous TiO 2 (c-TiO 2 /mp-TiO 2 )bilayer, and the holes are collected by the carbon layer. By adj usting the spray deposition cycles for the c-TiO 2 layer andUV-ozonetreatment,weachievedhysteresis-norm al, hysteresis-free, and hysteresis-inverted PSCs. Such unique trends of tunable hysteresis are anal yzed by considering the polarization of the TiO 2 /perovskite interface, which can accumulate positive charges reversibly. Successfully tuning of the hysteresis effect clarifies the critical importance of the c-TiO 2 /perovskite interface in controlling the hysteretic trends observed, providing important insights towards the understanding of this rapidly developing photovoltaic technology

Mets-IR as a predictor of cardiovascular events in the middle-aged and elderly population and mediator role of blood lipids

BackgroundCardiovascular disease (CVD) is a global health concern, with a significant impact on morbidity and mortality rates. Using fasting glucose, fasting triglycerides, body mass index (BMI), and high-density lipoprotein cholesterol (HDL-C), the metabolic score of insulin resistance (Mets-IR), a novel index created by Mexican researchers to assess insulin sensitivity, is a more precise way to measure insulin sensitivity. This study aimes to explore the association between Mets-IR and CVD, as well as investigate the potential mediating role of of low-density lipoprotein cholesterol (LDL-C).MethodsThe study’s data came from the 2011 and 2018 China Health and Retirement Longitudinal Studies (CHARLS). We used three logistic regression models to account for the potential effects of ten factors on cardiovascular disease/stroke/heart disease. Moreover, We performed mediation analyses to evaluate the role of LDL-C in the association between Mets-IR and incident CVD.ResultsThis study comprised 4,540 participants, of whom 494 (10.88%) were found to develop disease (CVD). Each interquartile range (IQR) increased in Mets-IR raised the risk of developing CVD by 38% (OR=1.38; 95% CI, 1.21-1.56) and there was a linear dose-response relationship between Mets-IR and the risk of new-onset cardiovascular disease, stroke, and heart disease (Poverall<0.05, Pnon-linear>0.05). Approximately 5% (indirect effect/total effect) of the significant association of Mets-IR with stroke was mediated by LDL-C, respectively. With the addition of Mets-IR to the base model, the continuous net reclassification improvement and integrated discrimination improvement for predicting cardiovascular disease increased by 0.175 (P <0.001) and 0.006 (P <0.001), respectively.Conclusionets-IR is associated with an increased risk of cardiovascular disease/stroke/cardiac issues, with LDL-C mediating these relationships. Improving insulin sensitivity and lipid regulation may be essential and effective preventive measures for cardiovascular events

Egg-Derived Folic Acid Protects against Lipopolysaccharide-Induced Oxidative Stress in Pregnant Mice and Neural Tube Defects in Fetal Mice

This study compared the effects of chemically synthesized folic acid and natural folic acid derived from duck egg yolk on health outcomes in pregnant mice induced by lipopolysaccharide (LPS) and their protective effects against neural tube defects in fetal mice. By observing the growth and appearance of fetal mice as well as assessing folate digestion and absorption in pregnant mice, redox homeostasis, and placental health, differences in the absorption of folates from different sources and their effects on oxidative stress levels in pregnant mice were explored. Evaluation of neural tube development in fetal mice, neural tube-related protein expression, antioxidant levels and inflammatory cytokine expression was conducted to analyze the potential of folate sources in preventing fetal neural tube defects and regulating inflammation levels in the body. The results demonstrated that both synthetic and egg-derived folic acids effectively improved the placental health of pregnant mice, with the latter being more effective in reducing LPS-induced damage in a dose-dependent manner. Egg-derived folate regulated the development of neural tube cells in fetal mice in a positive feedback manner, balanced the levels of superoxide dismutase, catalase, and glutathione peroxidase in the brain of fetal mice, and maintained the relative mRNA expression levels of IL-6, IL-1β, MCP-1, iNOS, and TNF-α in a healthy balance. High-dose egg-derived folate significantly increased the expression of neural cell adhesion molecule 1 (NCAM1), a protein associated with promoting neural tube development, demonstrating good potential for preventing neural tube defects and inhibit inflammation. These results underscore the importance of egg-derived folate for preventing neural tube defects and regulating inflammation in the body, providing a new theoretical and practical basis for developing the health benefits of food-derived folate

Interfacial energetics reversal strategy for efficient perovskite solar cells

Reducing heterointerface nonradiative recombination is a key challenge for realizing highly efficient perovskite solar cells (PSCs). Motivated by this, a facile strategy is developed via interfacial energetics reversal to functionalize perovskite heterointerface. A surfactant molecule, trichloro[3-(pentafluorophenyl)propyl]silane (TPFS) reverses perovskite surface energetics from intrinsic n-type to p-type, evidently demonstrated by ultraviolet and inverse photoelectron spectroscopies. The reconstructed perovskite surface energetics match well with the upper deposited hole transport layer, realizing an exquisite energy level alignment for accelerating hole extraction across the heterointerface. Meanwhile, TPFS further diminishes surface defect density. As a result, this cooperative strategy leads to greatly minimized nonradiative recombination. PSCs achieve an impressive power conversion efficiency of 25.9% with excellent reproducibility, and a nonradiative recombination-induced qVoc loss of only 57 meV, which is the smallest reported to date in n-i-p structured PSCs

A combined association of obesity, alanine aminotransferase and creatinine with hyperuricemia in youth aged 13–20 years

BackgroundDespite extensive research on hyperuricemia (HUA) in adults, there remains a dearth of studies examining this condition in youth. Consequently, our objective was to investigate the prevalence of HUA among youth in the United States, as well as identify the corresponding risk factors.MethodsThis study employed a nationally representative subsample of 1,051 youth aged 13–20 from the US National Health and Nutrition Examination Survey (NHANES) conducted between January 2017 and March 2020. Univariate and multivariate techniques were utilized to examine the association between HUA and obesity, dietary nutrients, liver and kidney function, glucose and lipid metabolism, inflammation, and other indicators in the adolescent population.ResultsThe study encompassed a cohort of 1,051 youth aged 13–20 years, comprising 538 boys and 513 girls. The overall prevalence of HUA was found to be 7% (74 out of 1,051). Univariate analysis revealed that the HUA group exhibited greater age, body mass index (BMI), waist circumference (WC), hip circumference (HC), and waist-to-hip ratio (WHR). Additionally, the prevalence of obesity was significantly higher in the HUA group compared to the non- HUA group (all p < 0.05). Regarding biochemical indicators, the levels of urea nitrogen, creatinine (Cr), alanine aminotransferase (ALT), glutamic oxalic aminotransferase (AST), gamma-glutamyl transferase (GGT), total cholesterol (TC), triglyceride (TG), and HS C reactive protein (Hs CRP) were found to be significantly higher in the HUA group compared to the non-HUA group (all p < 0.05). Further analysis using binary logistics regression showed that BMI (p = 0.024, OR1.158, 95%CI1.019–1.316), ALT (p = 0.020, OR1.032, 95%CI1.005–1.059), and Cr (p = 0.016, OR1.028, 95%CI1.005–1.051) were identified as risk factors for HUA, after controlling for age, gender, BMI, WC, HC, WHR, ALT, AST, GGT, TG, TC, Cr, Hs CRP, and other indicators. Interestingly, neither univariate nor multivariate analysis found any association between dietary nutrients and the risk of HUA (all p > 0.05).ConclusionHigh BMI remains a major risk factor for HUA in US youth aged 13–20 years, and ALT and Cr levels should be closely monitored along with serum uric acid

Optimized oxygen therapy improves sleep deprivation-induced cardiac dysfunction through gut microbiota

Adequate sleep is of paramount importance for relieving stress and restoring mental vigor. However, the adverse physiological and pathological responses resulting from sleep insufficiency or sleep deprivation (SD) are becoming increasingly prevalent. Currently, the impact of sleep deficiency on gut microbiota and microbiota-associated human diseases, especially cardiac diseases, remains controversial. Here, we employed the following methods: constructed an experimental sleep-deprivation model in mice; conducted 16S rRNA sequencing to investigate the changes in gut microbiota; through fecal microbiota transplantation (FMT) experiments, transplanted fecal microbiota from sleep-deprived mice to other mice; established an environment with a 30% oxygen concentration to explore the therapeutic effects of oxygen therapy on gut microbiota-associated cardiac fibrosis and dysfunction; and utilized transcriptome data to study the underlying mechanisms of oxygen therapy. The results revealed that: sleep-deprived mice exhibited weakness, depression-like behaviors, and dysfunction in multiple organs. Pathogenic cardiac hypertrophy and fibrosis occurred in sleep-deprived mice, accompanied by poor ejection fraction and fractional shortening. 16S rRNA sequencing indicated that sleep deprivation induced pathogenic effects on gut microbiota, and similar phenomena were also observed in mice that received fecal microbiota from sleep-deprived mice in the FMT experiments. The environment with a 30% oxygen concentration effectively alleviated the pathological impacts on cardiac function. Transcriptome data showed that oxygen therapy targeted several hypoxia-dependent pathways and inhibited the production of cardiac collagen. In conclusion, these results demonstrate the significance of sufficient sleep for gut microbiota and may represent a potential therapeutic strategy, where the oxygen environment exerts a protective effect on insomniacs through gut microbiota