分类: 核科学技术 >> 粒子加速器 提交时间: 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要: In order to do alignment between the timing signal and the synchrotron X-ray pulse on the sample spot in the time domain, measuring time structure of the storage ring on the sample spot inside the experimental hutch is a foundational step during the time-resolved experiments using the pulsed synchrotron X-rays with the time structure defined by the storage ring. In this work, the method of time-resolved X-ray excited optical luminescence (TRXEOL) was designed and implemented to do the measurement. It is based on the principle of time-correlated single photon counting techniques. The measurement system consists of a spectrometer with a detector of photomultiplier tube, a timing system, a set of nuclear instrument modules and a luminescent material of zinc oxide. The measurement was performed on the X-ray absorbed fine structure spectrum beamline at Shanghai Synchrotron Radiation Facility. The results show that this method can be used to measure the time structure of the storage ring with a precision of less than 1 ns. The measurement system can also be used for the time-resolved research for the optical luminescent materials.
分类: 计算机科学 >> 计算机科学的集成理论 提交时间: 2022-11-29 合作期刊: 《数据智能(英文)》
摘要: For many government departments, uncertainty aversion is a source of barriers in the advancement of data openness. A more active response to potential risks is needed and necessitates an in-depth examination of risks related to open government data (OGD). With a cross-case study in which three cases from the United Kingdom, the United States and China are examined, this study identifies potential risks that might emerge at different stages of the lifecycle of OGD programs and constructs a taxonomy model for them. The taxonomy model distinguishes the risks from OGD from the risks to OGD, which can help government departments make better responses. Finally, risk response strategies are suggested based on the research results.
分类: 生物学 >> 生物物理学 >> 生物物理、生物化学与分子生物学 提交时间: 2016-05-15
摘要: Multicellular organisms have multiple homologs of the yeast ATG8 gene, but the differential roles of these homologs in autophagy during development remain largely unknown. Here we investigated structure/function relationships in the two C. elegans Atg8 homologs, LGG-1 and LGG-2. lgg-1 is essential for degradation of protein aggregates, while lgg-2 has cargo-specific and developmental-stage-specific roles in aggregate degradation. Crystallography revealed that the N-terminal tails of LGG-1 and LGG-2 adopt the closed and open form, respectively. LGG-1 and LGG-2 interact differentially with autophagy substrates and Atg proteins, many of which carry a LIR motif. LGG-1 and LGG-2 have structurally distinct substrate binding pockets that prefer different residues in the interacting LIR motif, thus influencing binding specificity. Lipidated LGG-1 and LGG-2 possess distinct membrane tethering and fusion activities, which may result from the N-terminal differences. Our study reveals the differential function of two ATG8 homologs in autophagy during C. elegans development.