Interaction of H2+ molecular beam with thin layer graphene foils

The interaction of MeV H2^+ molecular ions with thin layer graphene and graphite foils was studied by using a highresolution electrostatic analyzer.A large number of fragment protons were observed at zero degree(along the beam direction) when the H2^+ beam was passing through the monolayer graphene foil, which indicates that the electron of the H2^+ molecular ions can be stripped easily even by the monolayer graphene foil.More trailing than leading protons were found in the energy spectrum, which means significant wake effect was observed in the monolayer graphene foil.The ratio of the numbers of trailing protons over leading protons first increased with the thickness for the much thinner graphene foils, and then decreased with the thickness for the much thicker graphite foils, which indicates that the bending effect of the wake field on the trailing proton varied with the foil thickness.

Interaction of supersonic molecular beam with low-temperature plasma

The interaction between the supersonic molecular beam(SMB)and the low-temperature plasma is a critical issue for the diagnosis and fueling in the Tokamak device.In this work,the interaction process between the argon SMB and the argon plasma is studied by a high-speed camera based on the Linear Experimental Advanced Device(LEAD)in Southwestern Institute of Physics,China.It is found that the high-density SMB can extinct the plasma temporarily and change the distribution of the plasma density significantly,while the low-density SMB can hardly affect the distribution of plasma density.This can be used as an effective diagnostic technique to study the evolution of plasma density in the interaction between the SMB and plasma.Moreover,the related simulation based on this experiment is carried out to better understand the evolution of electron density and ion density in the interaction.The simulation results can be used to analyze and explain the experimental results well.

Interaction between human telomeric G-quadruplexes characterized by single molecule magnetic tweezers

Human telomeric G-quadruplex plays a crucial role in regulating the genome stability. Despite extensive studies on structures and kinetics of monomeric G-quadruplex, the interaction between G-quadruplexes is still in debate. In this work,we employ magnetic tweezers to investigate the folding and unfolding kinetics of two contiguous G-quadruplexes in 100-mM K~＋buffer. The interaction between G-quadruplexes and the consequent effect on the kinetics of G-quadruplex are revealed. The linker sequence between G-quadruplexes is further found to play an important role in the interaction between two G-quadruplexes. Our results provide a high-resolution insight into kinetics of multimeric G-quadruplexes and genome stability.

High-Performanceα-Diimine Nickel Complexes for Facile Access of PE Elastomers with Exceptional Material Properties

For practicable elastomeric polyethylene,achieving high catalyst thermal stability and activity,along with precise control of polymer properties such as branching density,molecular weights,and distribution,is crucial but challenging.In this study,two sets of symmetricalα-diimine nickel complexes,each comprising four nickel bromide or chloride complexes,were synthesized and investigated their performance for ethylene polymerization under various reaction conditions.Upon activation with either Et2AlCl or MMAO cocatalysts,these complexes displayed not only high activity but also generated high molecular weight polyethylenes with controlled polydispersity and a substantial number of branches.The catalyst with the least steric hindrance displayed the remarkable high activity(up to 1.2×10^(7) g·mol^(-1)·h^(-1)).Notably,nickel bromides demonstrated higher activity compared to their chloride counterparts.The investigation into the effect of reaction temperature on catalytic performance revealed that NiBrMe-MMAO system displayed high thermal stability(activity up to 2.51×10^(6) g·mol^(-1)·h^(-1) at 100℃)and consistently yielded high polymer molecular weights with narrow polydispersity over a broad temperature range of 30-100℃.Of significant note,mechanical analysis of the resulting polyethylene demonstrated excellent ultimate tensile strength and high strain at break.Particularly,the polyethylene sample prepared at 100℃exhibited ultimate tensile strength up to 10 MPa with 1863%maximum strain at break and a strain recovery of up to 54.9%after ten cycles at a fixed strain of 300%,indicating excellent material properties of prepared thermoplastic polyethylene elastomers(TPE).

Novel mutation in ODF2 causes multiple morphological abnormalities of the sperm flagella in an infertile male

Numerous genes have been associated with multiple morphological abnormalities of the sperm flagella(MMAF),which cause severe asthenozoospermia and lead to male infertility,while the causes of approximately 50%of MMAF cases remain unclear.To reveal the genetic causes of MMAF in an infertile patient,whole-exome sequencing was performed to screen for pathogenic genes,and electron microscope was used to reveal the sperm flagellar ultrastructure.A novel heterozygous missense mutation in the outer dense fiber protein 2(ODF2)gene was detected,which was inherited from the patient’s mother and predicted to be potentially damaging.Transmission electron microscopy revealed that the outer dense fibers were defective in the patient’s sperm tail,which was similar to that of the reported heterozygous Odf2 mutation mouse.Immunostaining of ODF2 showed severe ODF2 expression defects in the patient’s sperm.Therefore,it was concluded that the heterozygous mutation in ODF2 caused MMAF in this case.To evaluate the possibility of assisted reproductive technology(ART)treatment for this patient,intracytoplasmic sperm injection(ICSI)was performed,with the help of a hypo-osmotic swelling test and laser-assisted immotile sperm selection(LAISS)for available sperm screening,and artificial oocyte activation with ionomycin was applied to improve the fertilization rate.Four ICSI cycles were performed,and live birth was achieved in the LAISS-applied cycle,suggesting that LAISS would be valuable in ART treatment for MMAF.

Effect of holistic stratification acupotomy on lower limb function,MMP1 and MMP13 in bursal fluid of patients with knee osteoarthritis:A randomized clinical trail

Objective:To observe the differences in clinical effect on knee osteoarthritis(KOA)between the holistic stratification acupotomy and the joint injection with sodium hyaluronate so as to provide a safe and effective treatment for KOA.Methods:A total of 100 KOA patients were randomly divided into an acupotomy group and a sodium hyaluronate group,50 patients in each one.In the acupotomy group,the holistic stratification acupotomy was adopted.In the sodium hyaluronate group,sodium hyaluronate injection was applied in the joints.The index of Western Ontario and McMaster University(WOMAC)and the expressions of MMP1 and MMP13 in bursal fluid of the patients were compared before and after treatment in the patients between two groups before and after treatment,and the clinical therapeutic effect was observed.Results:After treatment,WOMAC score of each dimension and the concentrations of MMP1 and MMP13 in bursal fluid of the patients of either group were all lower than those before treatment(all P<0.05).After treatment,WOMAC score of each dimension and the concentrations of MMP1 and MMP13 in bursal fluid in the acupotomy group were lower than the sodium hyaluronate group(all P<0.05).The total effective rate in the acupotomy group was higher than that of the sodium hyaluronate group(P<0.05).Conclusion:Both the holistic stratification acupotomy and the joint injection with sodium hyaluronate are effective on KOA in this trial.However,the therapeutic effect of holistic stratification acupotomy is remarkable,which is probably related to the improvements in inflammatory response.