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"Song-Zhan, Chen"
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A Universal Energy Relation between synchrotron and Synchrotron Self-Compton radiation in GRBs and Blazars
2024
The recent and brightest GRB 221009A observed by LHAASO marked the first detection of the onset of TeV afterglow, with a total of 7 GRBs exhibiting very high energy (VHE) afterglow radiation. However, consensus on VHE radiation of GRBs is still lacking. Multi-wavelength studies are currently a primary research method for investigating high-energy \\(\\gamma\\)-ray astronomy. The limited sample of VHE GRBs, combined with their transient nature, hinders the progress of physical studies of GRBs. This paper aims to obtain useful information for GRB research through the properties of blazars, which share significant similarities with GRBs. By fitting high-quality and simultaneous multiwavelength spectral energy distributions with a one-zone leptonic model, the study explores the similarity of radiation properties of blazars and GRBs. A tight correlation between synchrotron and synchrotron self-Compton (SSC) emission luminosities suggests that blazars and GRBs share similar radiation mechanisms, to be specific, synchrotron radiation produces the observed X-ray photons, which also serve as targets for electrons in the SSC process. We hope that ground-based experiments can observe more GRBs in sub-TeV to confirm these findings.
Expectation on probing the origin of the cosmic ray knee with the LHAASO experiment
2018
The cosmic-ray (CR) knee and the compositions contain abundant information for probing the CR's origin, acceleration and propagation mechanisms, as well as the frontier of the fundamental physics. Realizing that major proposals toward the knee's shape can be divided into two categories: the rigidity-dependent (also Z-dependent) knee and the mass-dependent (also A-dependent) knee, where the former one relates to the acceleration or the propagation mechanisms, and the other one is often associated with the new physics, it is essential to precisely measure the individual compositions. Benefit from the high altitude and hybrid detection methods, the LHAASO experiment has the ability in determining the individual component and brings us an opportunity in discriminating these two models. We test this expected ability of LHAASO from 100 TeV to 10 PeV with 3-year observation. And find the dominant component at the knee is essential to this issue, while much heavier nuclei occupying the knee leads to higher significance. In the analysis, the He-dominant knee under the A-dependent case can be recognized at the significance about 6.6 \\(\\sigma\\), while the P-dominant knee under the Z-dependent case will be classified with 2 \\(\\sigma\\) significance.
Dihydroartemisinin promotes angiogenesis during the early embryonic development of zebrafish
by
Qian BA Juan DUAN Jia-qiang TIAN Zi-liang WANG Tao CHEN Xiao-guang LI Pei-zhan CHEN Song-jie WU Li XlANG Jing-quan LI Rui-ai CHU Hui WANG
in
Animals
,
Animals, Genetically Modified
,
Artemisia - toxicity
2013
Aim: To investigate the embryotoxicity of dihydroartemisinin (DHA), the main active metabolite of artemisinin, in zebrafish, and explore the corresponding mechanisms. Methods: The embryos of wild type and TG (flkl:GFP) transgenic zebrafish were exposed to DHA. Developmental phenotypes of the embryos were observed. Development of blood vessels was directly observed in living embryos of TG (flkl:GFP) transgenic zebrafish under fluorescence microscope. The expression of angiogenesis marker genes vegfa, ilk1, and fit1 in the embryos was detected using real-time PCR and RNA in situ hybridization assays. Results: Exposure to DHA (1-10 mg/L) dose-dependently caused abnormal zebrafish embryonic phenotypes in the early developmental stage. Furthermore, exposure to DHA (10 mg/L) resulted in more pronounced embryonic angiogenesis in TG (flkl:GFP) zebrafish line. Exposure to DHA (10 mg/L) significantly increased the mRNA expression of veEfa, flkl, and fit1 in the embryos. Knockdown of the ilk1 protein partially blocked the effects of DHA on embryogenesis. Conclusion: DHA causes abnormal embryonic phenotypes and promotes angiogenesis in zebrafish early embryonic development, demonstrating the potential embryotoxicity of DHA.
Journal Article
A Universal Energy Relation between synchrotron and Synchrotron Self-Compton radiation in GRBs and Blazars
2024
The recent and brightest GRB 221009A observed by LHAASO marked the first detection of the onset of TeV afterglow, with a total of 7 GRBs exhibiting very high energy (VHE) afterglow radiation. However, consensus on VHE radiation of GRBs is still lacking. Multi-wavelength studies are currently a primary research method for investigating high-energy \\(\\gamma\\)-ray astronomy. The limited sample of VHE GRBs, combined with their transient nature, hinders the progress of physical studies of GRBs. This paper aims to obtain useful information for GRB research through the properties of blazars, which share significant similarities with GRBs. By fitting high-quality and simultaneous multiwavelength spectral energy distributions with a one-zone leptonic model, the study explores the similarity of radiation properties of blazars and GRBs. A tight correlation between synchrotron and synchrotron self-Compton (SSC) emission luminosities suggests that blazars and GRBs share similar radiation mechanisms, to be specific, synchrotron radiation produces the observed X-ray photons, which also serve as targets for electrons in the SSC process. We hope that ground-based experiments can observe more GRBs in sub-TeV to confirm these findings.
Classifying the Cosmic-Ray Proton and Light Groups on the LHAASO-KM2A Experiment with the Graph Neural Network
2019
Precise measurement about the cosmic-ray (CR) component knee is essential for revealing the mistery of CR's acceleration and propagation mechanism, as well as exploring the new physics. However, classification about the CR components is a tough task especially for the groups with the atomic number close to each other. Realizing that the deep learning has achieved a remarkable breakthrough in many fields, we seek for leveraging this technology to improve the classification performance about the CR Proton and Light groups on the LHAASO-KM2A experiment. In this work, we propose a fused Graph Neural Network model in combination of the KM2A arrays, in which the activated detectors are structured into graphs. We find that the signal and background can be effectively discriminated in this model, and its performance outperforms both the traditional physics-based method and the CNN-based model across the whole energy range.
Synthesis of insecticidal sucrose esters
2006
Some synthetic sucrose esters (SE) are a relatively new class of insecticidal compounds produced by reacting sugars with fatty acids, which are safe for the environment. Especially, sucrose esters composed of C^sub 6^-C^sub 12^ fatty acids have desirable insecticidal properties against many soft-bodied arthropod pests. In our study, sucrose octanoate which has the highest activity against a range of arthropod species was synthesized by a trans-esterification method and proved its insecticidal property. Under the condition of a homogeneous liquid, sucrose octanoate was prepared by reacting ethyl octanoate with sucrose at reduced pressure; the yield was 79.11%. Sucrose octanoate synthesized was identified and its property analyzed by IR, TLC and spectrophotometric analysis. It was shown that the ratio of monoester to polyester in sucrose octanoate was 1.48:1. The insecticidal activity of the synthetic sucrose octanoate was evaluated at a concentration of 4 and 8 mg·mL^sup -1^. The mortality of first-instar larvae of Lymantria dispar from its contact toxicity was 72.5% after 36 hours, the revision insect reduced rate of Aphis glycines reached above 80% at 4 and 8 mg·mL^sup -1^ after being treated for 5 days. Since the SE products are nontoxic to humans and higher animals, fully biodegradable and hydrolyzed to readily metabolizable sucrose and fatty acid, they are not harmful to crops and appear to be good insecticide candidates.[PUBLICATION ABSTRACT]
Journal Article
Ischemic stroke susceptibility gene in a Northern Han Chinese population
by
Haiping Wang Shujuan Shi Wenjing Yan Yan Song Jingjing Zhan Chen Zhang Haiji Wang
in
Apolipoproteins
,
Arteriosclerosis
,
Atherosclerosis
2013
Interleukin-18 gene promoter polymorphisms are potential risk factors for ischemic cerebrovascular disease, and the –607C allele may increase ischemic stroke risk in the Han Chinese population. In the present study, we recruited 291 patients with ischemic cerebrovascular disease from the Affiliated Hospital of Qingdao University Medical College, China, and 226 healthy controls. Both patients and controls were from the Han population in northern China. Immunoresonance scattering assays detected increased serum amyloid A protein, C-reactive protein, and interleukin-18 levels in ischemic cerebrovascular disease patients compared with healthy controls. Analysis of the –607C/A (rs1946518) polymorphism in the interleukin-18 gene promoter showed ischemic cerebrovascular disease patients exhibited increased frequencies of the CC genotype and C alleles than healthy controls. Genotype and allele frequencies of the interleukin-18 –137G/C (rs187238) polymorphism and the –13T/C (rs11024595) polymorphism in the 5'-flanking region of serum amyloid A, showed no significant difference between the two groups. Multivariate logistic regression analysis on the interleukin-18 promoter A/C genetic locus, for correction of age, gender, history of smoking, hypertension, diabetes mellitus, hypercholesteremia, and an ischemic stroke family history, showed ischemic cerebrovascular disease risk in individuals without the A allele (C homozygotes) was 2.2-fold greater than in A allele carriers. Overall, our findings suggest that the –13T/C (rs11024595) polymorphism in the 5′-flanking region of serum amyloid A has no correlation with ischemic cerebrovascular disease, but the C allele of the –607C/A (rs1946518) polymorphism in the interleukin-18 promoter is a high-risk factor for ischemic cerebrovascular disease in the Han population of northern China. In addition, the A allele is likely a protective gene for ischemic cerebrovascular disease.
Journal Article
The Large High Altitude Air Shower Observatory (LHAASO) Science Book (2021 Edition)
2022
Since the science white paper of the Large High Altitude Air Shower Observatory (LHAASO) published on arXiv in 2019 [e-Print: 1905.02773 (astro-ph.HE)], LHAASO has completed the transition from a project to an operational gamma-ray astronomical observatory LHAASO is a new generation multi-component facility located in Daocheng, Sichuan province of China, at an altitude of 4410 meters. It aims at measuring with unprecedented sensitivity the spectrum, composition, and anisotropy of cosmic rays in the energy range between 10\\(^{12}\\) and 10\\(^{18}\\)~eV, and acting simultaneously as a wide aperture (one stereoradiant) continuously operating gamma-ray telescope in the energy range between 10\\(^{11}\\) and \\(10^{15}\\)~eV with the designed sensitivity of 1.3\\% of the Crab Unit (CU) above 100 TeV. LHAASO's capability of measuring simultaneously different shower components (electrons, muons, and Cherenkov/fluorescence light), will allow it to investigate the origin, acceleration, and propagation of CR through measurement of the energy spectrum, elemental composition, and anisotropy with unprecedented resolution. The remarkable sensitivity of LHAASO will play a key role in CR physics and gamma-ray astronomy for a general and comprehensive exploration of the high energy universe and will allow important studies of fundamental physics (such as indirect dark matter search, Lorentz invariance violation, quantum gravity) and solar and heliospheric physics. The LHAASO Collaboration organized an editorial working group and finished all editorial work of this science book, to summarize the instrumental features and outline the prospects of scientific researches with the LHAASO experiment.
A state-of-the-art review on LSD1 and its inhibitors in breast cancer: Molecular mechanisms and therapeutic significance
by
Ding, Li-Jian
,
Xu, Zhan-Song
,
Shi, Zhen-Yuan
in
Breast cancer
,
Cancer therapies
,
Chemotherapy
2022
Breast cancer (BC) is a kind of malignant cancer in women, and it has become the most diagnosed cancer worldwide since 2020. Histone methylation is a common biological epigenetic modification mediating varieties of physiological and pathological processes. Lysine-specific demethylase 1 (LSD1), a first identified histone demethylase, mediates the removal of methyl groups from histones H3K4me1/2 and H3K9me1/2 and plays a crucial role in varieties of cancer progression. It is also specifically amplified in breast cancer and contributes to BC tumorigenesis and drug resistance via both demethylase and non-demethylase manners. This review will provide insight into the overview structure of LSD1, summarize its action mechanisms in BC, describe the therapeutic potential of LSD1 inhibitors in BC, and prospect the current opportunities and challenges of targeting LSD1 for BC therapy.
Journal Article
The Instant and Sustained Effect of Electroacupuncture in Postgraduate Students with Depression: An fMRI Study
2021
This study was a primary study to evaluate the instant and sustained effect of electroacupuncture (EA) at GV20 (Baihui) in postgraduate students with mild depression by using a special flexible head coil.
A total of 20 postgraduate students with mild depression underwent EA stimulation at GV20 and 3 phases of resting-state functional magnetic resonance imaging (rs-fMRI) scanning. Phase I: Preparation (before needle insertion); Phase II: during EA; Phase III: 15 minutes after needle removal. The Rs-fMRI data were processed using DPABI and SPSS 25.
1) ReHo values showed significantly differences in the right posterior cingulate cortex, right calcarine gyrus, right angular gyrus, right precuneus, right cuneus, and bilateral postcentral gyri among Phase I, Phase II and Phase III; 2) Relative to the Phase I, increased brain activity in the Phase II was observed in the bilateral postcentral gyri, right calcarine gyrus, right cuneus. Compared with the Phase II, decreased brain activity in the Phase III was observed in the right precuneus, right posterior cingulate cortex, right angular gyrus. Relative to the Phase I, Significantly increased brain activity in the Phase III was observed in the right calcarine gyrus, right cuneus, and bilateral postcentral gyri. While decreased ReHo values were found in the right posterior cingulate cortex, right angular gyrus, right precuneus; and 3) Correlation analysis showed that the ReHo values of multiple brain regions in Phase I and Phase III were significantly correlated with the VAS and HRSD-17 scores.
This study focuses on the instant and sustained effect in postgraduate students with depression. Our study showed that instant effect produced by EA stimulation at GV20 firstly induced changes in somatosensory and visual area, and then, sustained effect (Phase III) have a higher intensity and more extensive than instant effects. Meanwhile, we provide a visualization way to study the instant effects of head acupoints by using a flexible head coil.
Journal Article