Electron-ion collider in China Anderle, Daniele P.; Bertone, Valerio; Cao, Xu ...
Frontiers of physics,
12/2021, Letnik:
16, Številka:
6
Journal Article
Recenzirano
Odprti dostop
Lepton scattering is an established ideal tool for studying inner structure of small particles such as nucleons as well as nuclei. As a future high energy nuclear physics project, an Electron-ion ...collider in China (EicC) has been proposed. It will be constructed based on an upgraded heavy-ion accelerator, High Intensity heavy-ion Accelerator Facility (HIAF) which is currently under construction, together with a new electron ring. The proposed collider will provide highly polarized electrons (with a po- larization of 80%) and protons (with a polarization of 70%) with variable center of mass energies from 15 to 20 GeV and the luminosity of (2-3)×10 33 cm −2*s −1. Polarized deuterons and Helium-3, as well as unpolarized ion beams from Carbon to Uranium, will be also available at the EicC.
The main foci of the EicC will be precision measurements of the structure of the nucleon in the sea quark region, including 3D tomography of nucleon; the partonic structure of nuclei and the parton interaction with the nuclear environment; the exotic states, especially those with heavy flavor quark contents. In addition, issues fundamental to understanding the origin of mass could be addressed by measurements of heavy quarkonia near-threshold production at the EicC. In order to achieve the above-mentioned physics goals, a hermetical detector system will be constructed with cutting-edge technologies.
This document is the result of collective contributions and valuable inputs from experts across the globe. The EicC physics program complements the ongoing scientific programs at the Jefferson Laboratory and the future EIC project in the United States. The success of this project will also advance both nuclear and particle physics as well as accelerator and detector technology in China.
Cyclin-dependent kinase 2 (CDK2) is a member of serine/threonine protein kinases, which initiates the principal transitions of the eukaryotic cell cycle and is a promising target for cancer therapy. ...The present study was designed to inhibit cdk2 gene expression to induce cell cycle arrest and cell proliferation suppression. Here, we constructed a series of RNA interference (RNAi) plasmids which can successfully express small interference RNA (siRNA) in the transfected human cells. The results showed that the RNAi plasmids containing the coding sequences for siRNAs down-regulated the cdk2 gene expression in human cancer cells at the mRNA and the protein levels. Furthermore, we found that the cell cycle was arrested at G0G1 phases and the cell proliferation was inhibited by different siRNAs. These results demonstrate that suppression of CDK2 activity by RNAi may be an effective strategy for gene therapy in human cancers.
Electron-Ion Collider in China Anderle, Daniele P; Bertone, Valerio; Cao, Xu ...
arXiv.org,
02/2021
Paper, Journal Article
Odprti dostop
Lepton scattering is an established ideal tool for studying inner structure of small particles such as nucleons as well as nuclei. As a future high energy nuclear physics project, an Electron-ion ...collider in China (EicC) has been proposed. It will be constructed based on an upgraded heavy-ion accelerator, High Intensity heavy-ion Accelerator Facility (HIAF) which is currently under construction, together with a new electron ring. The proposed collider will provide highly polarized electrons (with a polarization of \(\sim\)80%) and protons (with a polarization of \(\sim\)70%) with variable center of mass energies from 15 to 20 GeV and the luminosity of (2-3) \(\times\) 10\(^{33}\) cm\(^{-2}\) s\(^{-1}\). Polarized deuterons and Helium-3, as well as unpolarized ion beams from Carbon to Uranium, will be also available at the EicC. The main foci of the EicC will be precision measurements of the structure of the nucleon in the sea quark region, including 3D tomography of nucleon; the partonic structure of nuclei and the parton interaction with the nuclear environment; the exotic states, especially those with heavy flavor quark contents. In addition, issues fundamental to understanding the origin of mass could be addressed by measurements of heavy quarkonia near-threshold production at the EicC. In order to achieve the above-mentioned physics goals, a hermetical detector system will be constructed with cutting-edge technologies. This document is the result of collective contributions and valuable inputs from experts across the globe. The EicC physics program complements the ongoing scientific programs at the Jefferson Laboratory and the future EIC project in the United States. The success of this project will also advance both nuclear and particle physics as well as accelerator and detector technology in China.
Within five different approaches to parton propagation and energy loss in dense matter, a phenomenological study of experimental data on suppression of large \(p_T\) single inclusive hadrons in ...heavy-ion collisions at both RHIC and LHC was carried out. The evolution of bulk medium used in the study for parton propagation was given by 2+1D or 3+1D hydrodynamic models which are also constrained by experimental data on bulk hadron spectra. Values for the jet transport parameter \(\hat q\) at the center of the most central heavy-ion collisions are extracted or calculated within each model, with parameters for the medium properties that are constrained by experimental data on the hadron suppression factor \(R_{AA}\). For a quark with initial energy of 10 GeV we find that \(\hat q\approx 1.2 \pm 0.3\) GeV\(^2\)/fm at an initial time \(\tau_0=0.6\) fm/\(c\) in Au+Au collisions at \(\sqrt{s}=200\) GeV/n and \(\hat q\approx 1.9 \pm 0.7 \) GeV\(^2\)/fm in Pb+Pb collisions at \(\sqrt{s}=2.76 \) TeV/n. Compared to earlier studies, these represent significant convergence on values of the extracted jet transport parameter, reflecting recent advances in theory and the availability of new experiment data from the LHC.
Evolution of graphene nanosheets (GNSs) during mechanical milling process was investigated to fabricate GNSs/Al nanocomposite by routes combined of pressure infiltration and hot extrusion. The ...structural integrity and dispersion homogeneity of GNSs together with the degree of interfacial reaction were systematically discussed. It was revealed that a moderate milling time existed for well dispersion and small quantities of Al4C3 (partial reaction bonding) via mechanical milling technique. A highest tensile strength of 276 MPa was obtained only with 0.3 wt% GNSs, which was 22.5% enhancement over the unreinforced Al matrix with the same preparation process and no decrease in elongation. Meanwhile, compared with reference Al, a great enhancement of electrical conductivity was achieved about 17.4%, which had not been reported previously. This study could provide new insights into the control factors of mechanical milling process for GNSs/Al composite and improve the interfacial bonding condition in situ during ball milling and subsequent densification processes to take full advantage of the extraordinary performance of graphene in metal matrix composites.
Display omitted
Liver-expressed antimicrobial peptide 2 (LEAP-2) is a cationic peptide that plays an important role in a host's innate immune system. We previously demonstrated that mudskipper (
) LEAP-2 (BpLEAP-2) ...induces chemotaxis and activation of monocytes/ macrophages (MO/MФ). However, the molecular mechanism by which BpLEAP-2 regulates MO/MΦ remains unclear. In this study, we used yeast two-hybrid cDNA library screening to identify mudskipper protein(s) that interacted with BpLEAP-2, and characterized a sequence encoding motile sperm domain-containing protein 2 (BpMOSPD2). The interaction between BpLEAP-2 and BpMOSPD2 was subsequently confirmed by co-immunoprecipitation (Co-IP). Sequence analyses revealed that the predicted BpMOSPD2 contained an N-terminal extracellular portion composed of a CRAL-TRIO domain and a motile sperm domain, a C-terminal transmembrane domain, and a short cytoplasmic tail. Phylogenetic tree analysis indicated that BpMOSPD2 grouped tightly with fish MOSPD2 homologs and was most closely related to that of the Nile tilapia (
). The recombinant BpMOSPD2 was produced by prokaryotic expression and the corresponding antibody was prepared for protein concentration determination. RNA interference was used to knockdown
expression in the mudskipper MO/MФ, and the knockdown efficiency was confirmed by quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting. Knockdown of
significantly inhibited BpLEAP-2-induced chemotaxis of mudskipper MO/MФ and BpLEAP-2-induced bacterial killing activity. Furthermore, knockdown of
inhibited the effect of BpLEAP-2 on mRNA expression levels of
,
,
, and
in MO/MФ. In general, BpMOSPD2 directly interacted with BpLEAP-2, and mediated the effects of BpLEAP-2 on chemotaxis and activation of mudskipper MO/MФ. This is the first identification of MOSPD2 as a receptor for LEAP-2.
Astragaloside IV (AS-IV) is one of the main pharmacologically active compounds found in Astragalus membranaceus. AS-IV has protective effects against ischemia–reperfusion injury (IRI), but its ...mechanism of action has not yet been determined. This study aims to investigate the effect of AS-IV on IRI and its effect on the phosphadylinositol 3-kinase (PI3K)/Akt/heme oxygenase (HO-1) signaling pathway through in vitro experiments. Firstly, a cell culture model of myocardiocyte hypoxia–reoxygenation (H/R) injury was replicated. After AS-IV treatment, cell viability, reactive oxygen species (ROS) levels, as well as the content or activity of the cellular factors lactate dehydrogenase (LDH), superoxide dismutase (SOD), malondialdehyde (MDA), interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α), were measured to evaluate the effect of treatment with AS-IV. The effect of AS-IV on HO-1 protein expression and nuclear factor E2-related factor 2 (Nrf2) and Bach1 protein expression was determined by Western blotting. Finally, a reversal of the effect of AS-IV treatment was observed following co-incubation with a PI3K inhibitor. Our results show that AS-IV has good protective effect on H/R injury and has anti-oxidative stress and anti-inflammatory effects. It can regulate the expression of Nrf2 and Bach1 proteins in the nucleus and promote the expression of HO-1 protein, while a PI3K inhibitor can partially reverse the above effects. This study suggests that the PI3K/Akt/HO-1 signaling pathway may be a key signaling pathway for the anti-IRI effect of AS-IV.
PDF
