Investigation of Projectile Impact Behaviors of Graphene Aerogel Using Molecular Dynamics Simulations

Graphene aerogel(GA),as a novel solid material,has shown great potential in engineering applications due to its unique mechanical properties.In this study,the mechanical performance of GA under high-velocity projectile impacts is thoroughly investigated using full-atomic molecular dynamics(MD)simulations.The study results show that the porous structure and density are key factors determining the mechanical response of GA under impact loading.Specifically,the impact-induced penetration of the projectile leads to the collapse of the pore structure,causing stretching and subsequent rupture of covalent bonds in graphene sheets.Moreover,the effects of temperature on the mechanical performance of GA have been proven to be minimal,thereby highlighting the mechanical stability of GA over a wide range of temperatures.Finally,the energy absorption density(EAD)and energy absorption efficiency(EAE)metrics are adopted to assess the energy absorption capacity of GA during projectile penetration.The research findings of this work demonstrate the significant potential of GA for energy absorption applications.

Optimization of Open-cast Mining Procedure Based on RSR Method

To explore the optimal evaluation mechanism of open-cast mining procedure,this paper takes the actual operation status of Huolinhe No.1 Open-cast Mine as the research basis,and makes a deep analysis of the four representative mining procedures proposed by this mine.A detailed and comprehensive evaluation system is constructed using rank-sum ratio(RSR)method.The system covers 17 key indicators and aims to evaluate the advantages and disadvantages of each scheme in an all-round and multi-angle manner.Through the calculation and analysis by RSR method,the comprehensive evaluation of the four types of mining procedure schemes is carried out,and finally the secondary river improvement project is determined as the optimal mining implementation scheme,and the joint mining scheme of the south and north areas is the alternative strategy.The research results of this paper are objective,clear and definite,can not only reveal the effectiveness and feasibility of RSR method in solving the problem of open-cast mining procedure optimization,but also provide a strong technical support and decision-making basis for the future production development of Huolinhe No.1 Open-cast Mine.Thus,this study is expected to further promote the scientific and refined process of mining operations.

The effect of gas additives on reactive species and bacterial inactivation by a helium plasma jet

In this paper,the influences of gas doping(O2,N2,Air)on the concentrations of reactive species and bactericidal effects induced by a He plasma jet are studied.Firstly,results show that gas doping causes an increase in voltage and a decrease in current compared with the pure He discharge under the same discharge power,which might be attributed to the different chemical characteristics of O2 and N2 and verified by the changes in the gaseous reactive species shown in the optical emission spectroscopy(OES)and Fourier transform infrared(FTIR)spectroscopy.Secondly,the concentrations of aqueous reactive oxygen species(ROS)and reactive nitrogen species(RNS)are tightly related to the addition of O2 and N2 into the working gas.The concentrations of aqueous NO-2 and NO-3 significantly increase while the concentrations of aqueous ROS decrease with the admixture of N2.The addition of O2 has little effect on the concentrations of NO-2 and NO-3 and pH values;however,the addition of O2 increases the concentration of O-2 and deceases the concentrations of H2O2 and OH.Finally,the results of bactericidal experiments demonstrate that the inactivation efficiency of the four types of plasma jets is He+O2>He+Air>He>He+N2,which is in accordance with the changing trend of the concentration of aqueous O.-2 Simultaneously to the better understanding of the formation and removal mechanisms of reactive species in the plasma–liquid interaction,these results also prove the effectiveness of regulating the concentrations of aqueous reactive species and the bacteria inactivation effects by gas doping.

Integrated proteomic profiling identifies amino acids selectively cytotoxic to pancreatic cancer cells

Pancreatic adenocarcinoma(PDAC)is one of the most deadly cancers,characterized by extremely limited therapeutic options and a poor prognosis,as it is often diagnosed during late disease stages.Innovative and selective treatments are urgently needed,since current therapies have limited efficacy and significant side effects.Through proteomics analysis of extracellular vesicles,we discovered an imbalanced distribution of amino acids secreted by PDAC tumor cells.Our findings revealed that PDAC cells preferentially excrete proteins with certain preferential amino acids,including isoleucine and histidine,via extracellular vesicles.These amino acids are associated with disease progression and can be targeted to elicit selective toxicity to PDAC tumor cells.Both in vitro and in vivo experiments demonstrated that supplementation with these specific amino acids effectively eradicated PDAC cells.Mechanistically,we also identified XRN1 as a potential target for these amino acids.The high selectivity of this treatment method allows for specific targeting of tumor metabolism with very low toxicity to normal tissues.Furthermore,we found this treatment approach is easy-to-administer and with sustained tumor-killing effects.Together,our findings reveal that exocytosed amino acids may serve as therapeutic targets for designing treatments of intractable PDAC and potentially offer alternative treatments for other types of cancers.

Human mesenchymal stromal cells enhance the immunomodulatory function of CD8＋CD28- regulatory T cells

One important aspect of mesenchymal stromal cells （MSCs）-mediated immunomodulation is the recruitment and induction of regulatory T （Treg） cells. However, we do not yet know whether MSCs have similar effects on the other subsets of Treg cells. Herein, we studied the effects of MSCs on CD8＋CD28- Treg cells and found that the MSCs could not only increase the proportion of CD8＋CD28- T cells, but also enhance CD8＋CD28-T cells＇ ability of hampering naive CD4＋ T-cell proliferation and activation, decreasing the production of IFN-γ by activated CD4＋ T cells and inducing the apoptosis of activated CD4＋ T cells. Mechanistically, the MSCs affected the functions of the CD8＋CD28- T cells partially through moderate upregulating the expression of IL-10 and FasL. The MSCs had no distinct effect on the shift from CD8＋CD28＋ T cells to CD8＋CD28- T cells, but did increase the proportion of CD8＋CD28- T cells by reducing their rate of apoptosis. In summary, this study shows that MSCs can enhance the regulatory function of CD8＋CD28- Treg cells, shedding new light on MSCs-mediated immune regulation.