近年来,随着宇宙线探测技术的不断提高,各空间探测实验对宇宙线粒子进行了高精度测量.其中,在宇宙线原初粒子和次级粒子能谱中,均发现在几百GV处存在能谱变硬特征.特别是,阿尔法磁谱仪2(Alpha Magnetic Spectrometer 2,AMS-2)实验发现...近年来,随着宇宙线探测技术的不断提高,各空间探测实验对宇宙线粒子进行了高精度测量.其中,在宇宙线原初粒子和次级粒子能谱中,均发现在几百GV处存在能谱变硬特征.特别是,阿尔法磁谱仪2(Alpha Magnetic Spectrometer 2,AMS-2)实验发现次级粒子相较原初粒子能谱变硬程度更为显著.目前,导致这一现象的原因还尚未有定论.论文利用AMS-2、反物质探测和轻核天体物理载荷(Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics,PAMELA)、先进成分探测器(Advanced Composition Explorer,ACE)中的宇宙线同位素光谱仪(Cosmic Ray Isotope Spectrometer,CRIS)(ACE-CRIS)以及旅行者1号(Voyager-1)探测器的最新实验数据对这一问题进行了研究.数据包括质子(p)和碳核(C)两种类型的原初粒子能谱以及锂碳比(Li/C)、铍碳比(Be/C)和硼碳比(B/C)3种类型的次级粒子原初粒子能谱比.论文分别假定高能区变硬现象是由发射谱拐折或是扩散拐折两种不同因素所导致,在此基础上对扩散-重加速(diffusionreacceleration,DR)以及扩散-对流(diffusion-convection,DC)两种不同的模型框架进行分析.在各模型框架下,计算结果显示:在低-中能区,各模型扩散指数δ_(L)的最佳估算值在0.41-0.48之间.其中,DR模型所需的δ_(L)值要比DC模型低0.06左右,这说明相较于对流,重加速机制会导致(Li,Be,B)/C在1至几百GeV/n之间的形状变陡.因此,拟合同样的(Li,Be,B)/C数据,DR模型所需的扩散指数更小.在高能区,结合暗物质探测卫星实验(the Dark Matter Particle Explorer,DAMPE)测量的B/C数据,我们发现相较于注入谱的高能拐折效应,DAMPE观测到的B/C高能区硬化现象更倾向于用扩散指数的变化来解释.不管是DR还是DC模型,得到的扩散指数拐折参数△δ都约为-0.19.展开更多
Background Recent studies have shown that interleukin-3 receptor α （CD123） is highly expressed on leukemia stem cells of patients with acute myeloid leukemia, and is correlated with tumor load and poor prognosis.Th...Background Recent studies have shown that interleukin-3 receptor α （CD123） is highly expressed on leukemia stem cells of patients with acute myeloid leukemia, and is correlated with tumor load and poor prognosis.The expression of CD123 may also be high in patients with myelodysplastic syndrome （MDS）.In this study, the expression and clinical significance of CD123 and granulocyte colony stimulating factor （G-CSF） receptor （CD114） on the bone marrow cells of patients with MDS were investigated to explore the molecular marker of the malignant clone of MDS.Methods Forty-two patients with MDS, who were diagnosed in the Hematological Department of General Hospital of Tianjin Medical University from 2008 to 2009, and twelve normal controls were enrolled in this study.Fluorescence activiated cell sorter （FACS） was used to measure the expression of CD123 on CD34＋CD38- cells and CD114 on CD34＋cells of the bone marrow of these patients and controls and the clinical significance was analyzed.The expression of CD114 on CD123＋CD34＋CD38- cells was further measured to explore the molecular marker of the malignant clone in MDS.Results MDS patients displayed significantly higher proportion of CD34＋CD38-/CD34＋ （（14.03±5.27）%） than normal controls （（7.70±4.36）%, P 〈0.05）.The expression rate of CD123＋CD34＋CD38-/CD34＋CD38- was significantly higher in MDS patients （（48.39±28.15）%） than that in normal controls （（8.75±11.71）%, P 〈0.01）.The expression level of CD123 was significantly correlated with the proportion of bone marrow blasts （r=0.457, P 〈0.05）.The expression rate of CD114＋CD34＋/CD34＋ was lower in MDS patients （（33.05±21.71）%） than that in normal controls （（38.99±19.07）%） but was not statistically significant （P 〉0.05）.The expression of CD114 on CD123＋CD34＋CD38- cells （（34.82±29.58）%） was significantly lower than that on CD123-CD34＋CD38- cells （（53.48±27.41）%） of M DS patients （P 〈0.05）.Conclusions MDS patients displayed higher proportion of CD34＋CD38-/CD34＋ than normal controls.CD123 was highly expressed in the bone marrow of the patients with MDS, significantly correlated with the proportion of bone marrow blasts, and thus might be the marker of MDS malignant clone.CD123＋CD34＋CD38- cells exhibited lower expression of G-CSF receptors, which might partly explain why MDS clone responds worse to G-CSF in vitro and in vivo.展开更多
文摘近年来,随着宇宙线探测技术的不断提高,各空间探测实验对宇宙线粒子进行了高精度测量.其中,在宇宙线原初粒子和次级粒子能谱中,均发现在几百GV处存在能谱变硬特征.特别是,阿尔法磁谱仪2(Alpha Magnetic Spectrometer 2,AMS-2)实验发现次级粒子相较原初粒子能谱变硬程度更为显著.目前,导致这一现象的原因还尚未有定论.论文利用AMS-2、反物质探测和轻核天体物理载荷(Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics,PAMELA)、先进成分探测器(Advanced Composition Explorer,ACE)中的宇宙线同位素光谱仪(Cosmic Ray Isotope Spectrometer,CRIS)(ACE-CRIS)以及旅行者1号(Voyager-1)探测器的最新实验数据对这一问题进行了研究.数据包括质子(p)和碳核(C)两种类型的原初粒子能谱以及锂碳比(Li/C)、铍碳比(Be/C)和硼碳比(B/C)3种类型的次级粒子原初粒子能谱比.论文分别假定高能区变硬现象是由发射谱拐折或是扩散拐折两种不同因素所导致,在此基础上对扩散-重加速(diffusionreacceleration,DR)以及扩散-对流(diffusion-convection,DC)两种不同的模型框架进行分析.在各模型框架下,计算结果显示:在低-中能区,各模型扩散指数δ_(L)的最佳估算值在0.41-0.48之间.其中,DR模型所需的δ_(L)值要比DC模型低0.06左右,这说明相较于对流,重加速机制会导致(Li,Be,B)/C在1至几百GeV/n之间的形状变陡.因此,拟合同样的(Li,Be,B)/C数据,DR模型所需的扩散指数更小.在高能区,结合暗物质探测卫星实验(the Dark Matter Particle Explorer,DAMPE)测量的B/C数据,我们发现相较于注入谱的高能拐折效应,DAMPE观测到的B/C高能区硬化现象更倾向于用扩散指数的变化来解释.不管是DR还是DC模型,得到的扩散指数拐折参数△δ都约为-0.19.
文摘Background Recent studies have shown that interleukin-3 receptor α （CD123） is highly expressed on leukemia stem cells of patients with acute myeloid leukemia, and is correlated with tumor load and poor prognosis.The expression of CD123 may also be high in patients with myelodysplastic syndrome （MDS）.In this study, the expression and clinical significance of CD123 and granulocyte colony stimulating factor （G-CSF） receptor （CD114） on the bone marrow cells of patients with MDS were investigated to explore the molecular marker of the malignant clone of MDS.Methods Forty-two patients with MDS, who were diagnosed in the Hematological Department of General Hospital of Tianjin Medical University from 2008 to 2009, and twelve normal controls were enrolled in this study.Fluorescence activiated cell sorter （FACS） was used to measure the expression of CD123 on CD34＋CD38- cells and CD114 on CD34＋cells of the bone marrow of these patients and controls and the clinical significance was analyzed.The expression of CD114 on CD123＋CD34＋CD38- cells was further measured to explore the molecular marker of the malignant clone in MDS.Results MDS patients displayed significantly higher proportion of CD34＋CD38-/CD34＋ （（14.03±5.27）%） than normal controls （（7.70±4.36）%, P 〈0.05）.The expression rate of CD123＋CD34＋CD38-/CD34＋CD38- was significantly higher in MDS patients （（48.39±28.15）%） than that in normal controls （（8.75±11.71）%, P 〈0.01）.The expression level of CD123 was significantly correlated with the proportion of bone marrow blasts （r=0.457, P 〈0.05）.The expression rate of CD114＋CD34＋/CD34＋ was lower in MDS patients （（33.05±21.71）%） than that in normal controls （（38.99±19.07）%） but was not statistically significant （P 〉0.05）.The expression of CD114 on CD123＋CD34＋CD38- cells （（34.82±29.58）%） was significantly lower than that on CD123-CD34＋CD38- cells （（53.48±27.41）%） of M DS patients （P 〈0.05）.Conclusions MDS patients displayed higher proportion of CD34＋CD38-/CD34＋ than normal controls.CD123 was highly expressed in the bone marrow of the patients with MDS, significantly correlated with the proportion of bone marrow blasts, and thus might be the marker of MDS malignant clone.CD123＋CD34＋CD38- cells exhibited lower expression of G-CSF receptors, which might partly explain why MDS clone responds worse to G-CSF in vitro and in vivo.
