UPLC-HRMSⁿ 结合高能诱导裂解快速鉴定麦冬中高异黄酮类成分

应用UPLC-LTQ-Orbitrap法快速鉴定麦冬药材中高异黄酮类化合物,考察不同高能诱导裂解(HCD)能量下高异黄酮的裂解情况,优选特征碎片离子对进行鉴定,并探索麦冬中高异黄酮类成分的裂解规律。应用该方法在麦冬提取物中鉴定出68个高异黄酮类成分,其中包括26个高异黄酮成分,31个高异黄烷酮成分,11个高异黄酮糖苷类成分。结果表明,HCD模式能够提供丰富稳定的裂解碎片离子信息,结合UPLC-LTQ-Orbitrap技术能够快速准确地鉴定复杂组分中高异黄酮类成分,可为中药系列成分研究提供有价值的方法参考。Radix Ophiopogon,a kind of traditional Chinese medicine,is the root of Liliaceae Ophiopogon japonicus(Thunb.)Ker Gaw l.Modern research demonstrates that Ophiopogon japonicas can be used as a folk food medicine in free radical scavenging,reducing blood sugar,sedative hypnotic and anti-myocardial ischemia and arrhythmia,and so on.The major chemical compounds of this plant are mainly homoisoflavonoids,steroidal saponins and polysaccharides. According to the relevant reports,thehomoisoflavonoids is a kind of specific compounds in Ophiopogon japonicus.However,due to the large number of different types of homoisoflavonoids in the herbal medicine,the structures are too similar to be distinguished from each other.Meanwhile,the differences of their relative contents in Ophiopogon japonicas are great.In this paper,the rapid separation ability of UPLC-LTQ-Orbitrap and the higher energy collision induced dissociation mode(HCD mode)were used to acquire high resolution fragment ion information and studied on the fragmentation patterns of homoisoflavonoids.The chromatographic separation of Ophiopogon japonicus extract was used Waters Acuqity UPLCTMBEH C18 column,mobile phase was 0.05%formic acid in water and acetonitrile system,and the chromatographic conditions for the rapid separation were optimized.To avoid interference with other components and obtain the tandem mass spectrometry high content and low content data,a method based on parent ions detection list in the negative ion mode detection was established.Furthermore,the established method was helpful in investigating the dissociation pathways of homoisoflavonoids in different HCD cleavage energy and confirming the characteristic fragment ions for the identification.Meanwhile,68 constituents attributed to homoisoflavonoids in Ophiopogon japonicas are finally identified,including 26 homoisoflavonoids,31homoisoflavanones,and 11 homoisoflavonoids glycosides.The results indicate that the HCD model can provide abundant and stable information of fragment ions,which can be adopted to quickly and accurately clarify the homoisoflavonoids in complex system.This study can provide an effective analytical method to explore the material basis of sequential constituents in traditional Chinese medicines

Expert consensus on multimodal MRI sequence parameters and scanning protocols for studies of brain and cognitive development in school‑aged children

当代多模态MRI技术的迅速发展，为精准刻画儿童青少年脑发育规律与个体差异、揭示 脑发育异常疾病的神经机制，提供了重要影像研究工具，带来了儿童脑发育影像学这一脑科学前沿方 向。然而，面向学龄儿童（6~18 岁）的高质量多模态 MRI 脑影像序列参数设置与扫描采集极具挑战 性，严重阻碍了国内脑发育相关影像研究的开展与推广。为此，国内相关领域的多家权威机构和专家 团队，依托科技部科技创新2030&ldquo; 脑科学与类脑研究&rdquo;重大项目&ldquo;中国学龄儿童脑智队列&rdquo;计划，通过 调研全国 30余家机构 MRI设备现况，以及国际大型儿童脑发育队列研究序列参数的优缺点，共同制 订了《面向学龄儿童脑智发育研究的多模态MRI脑影像序列参数与扫描规范专家共识》，以期规范国 内不同规模、不同类型队列相关脑发育影像研究中的序列参数设计与扫描操作，提升儿童脑影像扫描成功率与影像质量，以及结果可比性与稳定性，推动我国儿童脑智发育基础与临床研究的整体进步。</p

Measurement of integrated luminosity of data collected at 3.773 GeV by BESIII from 2021 to 2024

We present a measurement of the integrated luminosity e+e- of collision data collected by the BESIII detector at the BEPCII collider at a center-of-mass energy of Ecm = 3.773 GeV. The integrated luminosities of the datasets taken from December 2021 to June 2022, from November 2022 to June 2023, and from October 2023 to February 2024 were determined to be 4.995±0.019 fb-1, 8.157±0.031 fb-1, and 4.191±0.016 fb-1, respectively, by analyzing large angle Bhabha scattering events. The uncertainties are dominated by systematic effects, and the statistical uncertainties are negligible. Our results provide essential input for future analyses and precision measurements

Determination of the number of ψ(3686) events taken at BESIII

The number of ψ(3686) events collected by the BESIII detector during the 2021 run period is determined to be (2259.3±11.1)×106 by counting inclusive ψ(3686) hadronic events. The uncertainty is systematic and the statistical uncertainty is negligible. Meanwhile, the numbers of ψ(3686) events collected during the 2009 and 2012 run periods are updated to be (107.7±0.6)×106 and (345.4±2.6)×106, respectively. Both numbers are consistent with the previous measurements within one standard deviation. The total number of ψ(3686) events in the three data samples is (2712.4±14.3)×10^