The recently deployed Transition Region Explorer(TREx)-RGB(red-green-blue)all-sky imager(ASI)is designed to capture“true color”images of the aurora and airglow.Because the 557.7 nm green line is usually the brightes...The recently deployed Transition Region Explorer(TREx)-RGB(red-green-blue)all-sky imager(ASI)is designed to capture“true color”images of the aurora and airglow.Because the 557.7 nm green line is usually the brightest emission line in visible auroras,the green channel of a TREx-RGB camera is usually dominated by the 557.7 nm emission.Under this rationale,the TREx mission does not include a specific 557.7 nm imager and is designed to use the RGB green-channel data as a proxy for the 557.7 nm aurora.In this study,we present an initial effort to establish the conversion ratio or formula linking the RGB green-channel data to the absolute intensity of 557.7 nm auroras,which is crucial for quantitative uses of the RGB data.We illustrate two approaches:(1)through a comparison with the collocated measurement of green-line auroras from the TREx spectrograph,and(2)through a comparison with the modeled green-line intensity according to realistic electron precipitation flux measurements from low-Earth-orbit satellites,with the aid of an auroral transport model.We demonstrate the procedures and provide initial results for the TREx-RGB ASIs at the Rabbit Lake and Lucky Lake stations.The RGB response is found to be nonlinear.Empirical conversion ratios or formulas between RGB green-channel data and the green-line auroral intensity are given and can be applied immediately by TREx-RGB data users.The methodology established in this study will also be applicable to the upcoming SMILE ASI mission,which will adopt a similar RGB camera system in its deployment.展开更多
目的探讨伴白质脑病和系统性损害的视网膜血管病(retinal vasculopathy with cerebral leukoencephalopathy and systemic manifestations,RVCL-S)家系的临床、组织病理及分子遗传学特点。方法回顾性分析RVCL-S家系的临床资料并绘制家系...目的探讨伴白质脑病和系统性损害的视网膜血管病(retinal vasculopathy with cerebral leukoencephalopathy and systemic manifestations,RVCL-S)家系的临床、组织病理及分子遗传学特点。方法回顾性分析RVCL-S家系的临床资料并绘制家系图,总结其临床表现、影像学、组织病理及分子遗传学特点。结果家系1:男性发病3例,年龄分别为10岁、29岁和40岁。家系2:男性发病1例,年龄为32岁。2家系患者均表现为视网膜血管病、白质脑病及多系统损害,后者包括肝、肾、消化道受累等;2家系无症状携带者4例。家系1-Ⅱ2颅脑CT示左侧侧脑室后角旁片状低密度,伴颅内多发高密度钙化,颅脑MRI平扫示侧脑室旁病变;家系1-Ⅱ5颅脑MRI平扫及增强示额颞叶皮层病变伴周围水肿及占位效应,环形强化明显。家系2-Ⅱ1颅脑MRI平扫及增强先后出现右侧及左侧额叶病变,伴周围水肿及强化,占位效应明显。家系1-Ⅱ5病变脑组织手术病理示内皮细胞增生性病变;家系2-Ⅱ1脑病变2次手术病理均符合“脑梗死”样表现;小肠壁内小血管示内皮细胞增生性病变。家系1-Ⅱ2存在TREX1 D272Rfs杂合突变,其2女1子均为无症状突变携带者。家系2-Ⅱ1基因存在TREX1 S246Ifs杂合突变,其父亲、母亲均未发现该突变,其子为无症状突变携带者。结论RVCL-S临床主要表现为视网膜血管病、神经系统受累及多系统损害。影像学见颅内病变可呈占位性,伴周围水肿及强化;病理特点为小血管内皮细胞增生及管腔狭窄。基因结果证实存在TREX1基因突变。展开更多
生物体中遗传信息的传递遵循中心法则,即从基因组DNA传递到RNA,再进一步传递到蛋白质。作为遗传信息传递的中间一环,RNA需要在细胞核中生成,并进一步被转运到细胞质中,其中涉及的RNA出核转运过程则是保证遗传信息精确传递的重要步骤,并...生物体中遗传信息的传递遵循中心法则,即从基因组DNA传递到RNA,再进一步传递到蛋白质。作为遗传信息传递的中间一环,RNA需要在细胞核中生成,并进一步被转运到细胞质中,其中涉及的RNA出核转运过程则是保证遗传信息精确传递的重要步骤,并参与了基因表达的精确调控过程。绝大多数的mRNA通常在细胞核内包装形成mRNP,并在TREX复合体(transcription-export complex,TREX)和出核因子NXF1(nuclear RNA export factor 1)的帮助下转运出核。另有一小部分的mRNA则以CRM1(chromosome region maintenance protein 1)依赖的方式进行出核转运。大量研究表明,mRNA出核过程不仅与上游的转录和加工相偶联,而且能够反向调控上游步骤。此外,细胞核中RNA的出核机器与降解机器相互竞争,共同决定新生RNA的核内命运。尤为重要的是,当mRNA出核受阻时,在细胞和个体层面上会产生不同程度的生理或病理缺陷。最新的研究表明,除mRNA以外,circRNA和lncRNA等其他RNA分子也被认为能够转运出核并翻译产生蛋白质,参与各类生物学过程的调控,其出核过程则涉及一些新的受体因子和调控蛋白。本文将结合最新的研究进展,对已知RNA出核转运通路的相关具体过程和调控机制进行总结,并对领域内后续研究的重难点进行讨论和展望。展开更多
基金jointly funded by the Canada Foundation for Innovationthe Alberta Economic Development and Trade organization+1 种基金the University of Calgarysupported by the Canadian Space Agency。
文摘The recently deployed Transition Region Explorer(TREx)-RGB(red-green-blue)all-sky imager(ASI)is designed to capture“true color”images of the aurora and airglow.Because the 557.7 nm green line is usually the brightest emission line in visible auroras,the green channel of a TREx-RGB camera is usually dominated by the 557.7 nm emission.Under this rationale,the TREx mission does not include a specific 557.7 nm imager and is designed to use the RGB green-channel data as a proxy for the 557.7 nm aurora.In this study,we present an initial effort to establish the conversion ratio or formula linking the RGB green-channel data to the absolute intensity of 557.7 nm auroras,which is crucial for quantitative uses of the RGB data.We illustrate two approaches:(1)through a comparison with the collocated measurement of green-line auroras from the TREx spectrograph,and(2)through a comparison with the modeled green-line intensity according to realistic electron precipitation flux measurements from low-Earth-orbit satellites,with the aid of an auroral transport model.We demonstrate the procedures and provide initial results for the TREx-RGB ASIs at the Rabbit Lake and Lucky Lake stations.The RGB response is found to be nonlinear.Empirical conversion ratios or formulas between RGB green-channel data and the green-line auroral intensity are given and can be applied immediately by TREx-RGB data users.The methodology established in this study will also be applicable to the upcoming SMILE ASI mission,which will adopt a similar RGB camera system in its deployment.
文摘目的探讨伴白质脑病和系统性损害的视网膜血管病(retinal vasculopathy with cerebral leukoencephalopathy and systemic manifestations,RVCL-S)家系的临床、组织病理及分子遗传学特点。方法回顾性分析RVCL-S家系的临床资料并绘制家系图,总结其临床表现、影像学、组织病理及分子遗传学特点。结果家系1:男性发病3例,年龄分别为10岁、29岁和40岁。家系2:男性发病1例,年龄为32岁。2家系患者均表现为视网膜血管病、白质脑病及多系统损害,后者包括肝、肾、消化道受累等;2家系无症状携带者4例。家系1-Ⅱ2颅脑CT示左侧侧脑室后角旁片状低密度,伴颅内多发高密度钙化,颅脑MRI平扫示侧脑室旁病变;家系1-Ⅱ5颅脑MRI平扫及增强示额颞叶皮层病变伴周围水肿及占位效应,环形强化明显。家系2-Ⅱ1颅脑MRI平扫及增强先后出现右侧及左侧额叶病变,伴周围水肿及强化,占位效应明显。家系1-Ⅱ5病变脑组织手术病理示内皮细胞增生性病变;家系2-Ⅱ1脑病变2次手术病理均符合“脑梗死”样表现;小肠壁内小血管示内皮细胞增生性病变。家系1-Ⅱ2存在TREX1 D272Rfs杂合突变,其2女1子均为无症状突变携带者。家系2-Ⅱ1基因存在TREX1 S246Ifs杂合突变,其父亲、母亲均未发现该突变,其子为无症状突变携带者。结论RVCL-S临床主要表现为视网膜血管病、神经系统受累及多系统损害。影像学见颅内病变可呈占位性,伴周围水肿及强化;病理特点为小血管内皮细胞增生及管腔狭窄。基因结果证实存在TREX1基因突变。
文摘生物体中遗传信息的传递遵循中心法则,即从基因组DNA传递到RNA,再进一步传递到蛋白质。作为遗传信息传递的中间一环,RNA需要在细胞核中生成,并进一步被转运到细胞质中,其中涉及的RNA出核转运过程则是保证遗传信息精确传递的重要步骤,并参与了基因表达的精确调控过程。绝大多数的mRNA通常在细胞核内包装形成mRNP,并在TREX复合体(transcription-export complex,TREX)和出核因子NXF1(nuclear RNA export factor 1)的帮助下转运出核。另有一小部分的mRNA则以CRM1(chromosome region maintenance protein 1)依赖的方式进行出核转运。大量研究表明,mRNA出核过程不仅与上游的转录和加工相偶联,而且能够反向调控上游步骤。此外,细胞核中RNA的出核机器与降解机器相互竞争,共同决定新生RNA的核内命运。尤为重要的是,当mRNA出核受阻时,在细胞和个体层面上会产生不同程度的生理或病理缺陷。最新的研究表明,除mRNA以外,circRNA和lncRNA等其他RNA分子也被认为能够转运出核并翻译产生蛋白质,参与各类生物学过程的调控,其出核过程则涉及一些新的受体因子和调控蛋白。本文将结合最新的研究进展,对已知RNA出核转运通路的相关具体过程和调控机制进行总结,并对领域内后续研究的重难点进行讨论和展望。
