Noether-Mei Symmetry of Mechanical System in Phase Space

In this paper, a new kind of symmetry and its conserved quantities of a mechanical system in phase space are studied. The definition of this new symmetry, i.e., a Noether-Mei symmetry, is presented, and the criterion of this symmetry is also given. The Noether conserved quantity and the Mei conserved quantity deduced from the Noether-Mei symmetry of the system are obtained. Finally, two examples are given to illustrate the application of the results.     

Detoxified pneumolysin derivative ΔA146Ply inhibits autophagy and induces apoptosis in acute myeloid leukemia cells by activating mTOR signaling

Leukemia is caused by the malignant clonal expansion of hematopoietic stem cells, and in adults, the most common type of leukemia is acute myeloid leukemia (AML). Autophagy inhibitors are often used in preclinical and clinical models in leukemia therapy. However, clinically available autophagy inhibitors and their efficacy are very limited. More effective and safer autophagy inhibitors are urgently needed for leukemia therapy. In a previous study, we showed that ΔA146Ply, a mutant of pneumolysin that lacks hemolytic activity, inhibited autophagy of triple-negative breast cancer cells by activating mannose receptor (MR) and toll-like receptor 4 (TLR4) and that tumor-bearing mice tolerated ΔA146Ply well. Whether this agent affects AML cells expressing TLR4 and MR and the related mechanisms remain to be determined. In this study, we found that ΔA146Ply inhibited autophagy and induced apoptosis in AML cells. A mechanistic study showed that ΔA146Ply inhibited autophagy by activating mammalian target of rapamycin signaling and induced apoptosis by inhibiting autophagy. ΔA146Ply also inhibited autophagy and induced apoptosis in a mouse model of AML. Furthermore, the combination of ΔA146Ply and chloroquine synergistically inhibited autophagy and induced apoptosis in vitro and in vivo. Overall, this study provides an alternative effective autophagy inhibitor that may be used for leukemia therapy.Subject terms: Translational research, Acute myeloid leukaemia     

Removal of Carbamazepine in Aqueous Solution by CoS2/Fe2+/PMS Process

Carbamazepine (CBZ), as a typical pharmaceutical and personal care product (PPCP), cannot be efficiently removed by the conventional drinking water and wastewater treatment process. In this work, the CoS₂/Fe²⁺/PMS process was applied for efficient elimination of CBZ. The CBZ removal efficiency of CoS₂/Fe²⁺/PMS was 2.5 times and 23 times higher than that of CoS₂/PMS and Fe²⁺/PMS, respectively. The intensity of DMPO-HO• and DMPO-SO4•− followed the order of Fe²⁺/PMS < CoS₂/PMS < CoS₂/Fe²⁺/PMS, also suggesting the CoS₂/Fe²⁺/PMS process has the highest oxidation activity. The effects of reaction conditions (e.g., CoS₂ dosage, Fe²⁺ concentration, PMS concentration, initial CBZ concentration, pH, temperature) and water quality parameters (e.g., SO42−, NO3−, H2PO4−, Cl−, NH4+, humic acid) on the degradation of CBZ were also studied. Response surface methodology analysis was carried out to obtain the best conditions for the removal of CBZ, which are: Fe²⁺ = 70 µmol/L, PMS = 240 µmol/L, CoS₂ = 0.59 g/L. The sustainability test demonstrated that the repeated use of CoS₂ for 8 successive cycles resulted in little function decrease (<10%). These findings suggest that CoS₂/Fe²⁺/PMS may be a promising method for advanced treatment of tailwater from sewage treatment plant.     

耦合FE/WB法在声分析中的应用

简要描叙FE法(finite element method)和WB法(wave based method)的理论背景以及耦合FE/WB法的数学基础.耦合FE/WB法利用两者的优势——FE法的广泛应用和WB法的高收敛特性,将FE模型中较大且几何简单的部分采用WB法代替.耦合模型具有相对较少的自由度.对于较高的频率还可以进行细分得到更高的计算精度,并利用模态缩减法进一步减少自由度数.数值算例结果表明,该耦合方法有潜力覆盖中频段的声分析.     

Bioavailability Enhancement of Cepharanthine via Pulmonary Administration in Rats and Its Therapeutic Potential for Pulmonary Fibrosis Associated with COVID-19 Infection

Cepharanthine (CEP) has excellent anti-SARS-CoV-2 properties, indicating its favorable potential for COVID-19 treatment. However, its application is challenged by its poor dissolubility and oral bioavailability. The present study aimed to improve the bioavailability of CEP by optimizing its solubility and through a pulmonary delivery method, which improved its bioavailability by five times when compared to that through the oral delivery method (68.07% vs. 13.15%). An ultra-performance liquid chromatography tandem-mass spectrometry (UPLC-MS/MS) method for quantification of CEP in rat plasma was developed and validated to support the bioavailability and pharmacokinetic studies. In addition, pulmonary fibrosis was recognized as a sequela of COVID-19 infection, warranting further evaluation of the therapeutic potential of CEP on a rat lung fibrosis model. The antifibrotic effect was assessed by analysis of lung index and histopathological examination, detection of transforming growth factor (TGF)-β1, interleukin-6 (IL-6), α-smooth muscle actin (α-SMA), and hydroxyproline level in serum or lung tissues. Our data demonstrated that CEP could significantly alleviate bleomycin (BLM)-induced collagen accumulation and inflammation, thereby exerting protective effects against pulmonary fibrosis. Our results provide evidence supporting the hypothesis that pulmonary delivery CEP may be a promising therapy for pulmonary fibrosis associated with COVID-19 infection.     

A Simple Hydrothermal Method for the Growth of ZnO Crystals

ZnO microstructures have been grown from zinc chloride (ZnCl₂) and ammonia solution at 100 °C for 1 – 24 hours. X‐ray diffraction, scanning electron microscope and field‐emission scanning microscope were utilized to investigate the structural properties and morphology of the ZnO crystals. Structural investigations show that phase‐pure hexagonal structure ZnO has been successfully synthesized, and the hexagonal structure ZnO can be achieved in solutions with an appropriate range of concentrations. Under our experimental conditions, several different morphologies of ZnO structures were obtained, including flower‐like and bar flower‐like. The relationship between the morphology and experimental conditions are discussed.     

（Ti,Al）N薄膜光学性能的研究

研究了（Ｔｉ，Ａｌ）薄膜的光学特性，对其反射和透射光谱作了仔细分析。运用Ｈａｄｌｅｙ方程，算出一定成分（Ｔｉ，Ａｌ）Ｎ膜的折射率ｎ，消光系数ｋ随波长的变化关系。又根据透射曲线，计算出了（Ｔｉ，Ａｌ）Ｎ膜的光隙能。     

基于一维光子晶体超晶格的多通道平顶透射特性

基于一维光子晶体超晶格理论及耦合腔理论,提出了一种具有多个平顶透射峰的超晶格结构.把传统单一材料的耦合腔换成有限周期的光子晶体结构,形成一种超晶格结构.通过使插入的光子晶体的光场有效耦合,能够产生多个平顶透射峰.运用传输矩阵法,研究了该结构的光谱特性以及结构和材料参量对透射峰的位置和半峰全宽的影响.计算结果表明,该结构具有较宽的带隙,并且多个平顶透射峰对称分布,透射率高,误差容忍度好.详细讨论了透射峰确切位置的计算方法,并给出了严格的解析表达式.     

Effects of Organic Acids on the Release of Fruity Esters in Water: An Insight at the Molecular Level

It is well known that organic acids (OAs) could affect the flavour of fruit juices and beverages. However, the molecular mechanism of aroma release is still unclear. In this study, the effects of citric acid (CA), L-(-)-malic acid (MA) and L-lactic acid (LA) on the release of six selected esters and their sensory perception were investigated by means of HS-GC-MS analyses and odour detection threshold determination, respectively. Meanwhile, the density functional theory (DFT) calculation was employed to explore the interaction modes between esters and OAs. HS-GC-MS analyses showed that the concentration and the type of OAs regulated the release of esters. The results were basically consistent with the detection threshold change of those esters. The DFT calculation suggested that the main intermolecular interaction was hydrogen bonds, and several esters could form a ternary ring structure with OAs through hydrogen bonds. The interactions can induce the different release behaviours of esters in OAs water solution. The number of carboxyl functional groups in OAs and the spatial conformation of esters appeared to influence the magnitude of the interaction. The above results demonstrated the mechanism of OAs affecting the release of esters and indicated a possible flavour control way by using different OAs and OA concentrations.     

Superhydrophobic Flexible Supercapacitors Formed by Integrating Hydrogel with Functional Carbon Nanomaterials

Main observation and conclusion With the rapid development of the wearable electronics,the flexible supercapacitor with high energy density has attracted more a...