北京山区不同植被恢复类型土壤质量综合评价

[目的]综合评价北京山区不同植被恢复类型土壤质量,并进一步确定影响土壤质量的关键因素,为该地区植被恢复与重建提供数据支撑。[方法]以立地条件相近的侧柏纯林、油松纯林、侧柏油松混交林、侧柏针阔混交林、油松针阔混交林、落叶阔叶混交林和无林地(对照)为研究对象,测定14个土壤理化指标作为土壤质量评价的总数据集(TDS),采用主成分分析法(PCA)和Pearson相关性分析建立土壤质量最小数据集(MDS),利用线性(L)和非线性(NL)2种评分方法计算土壤质量指数(SQI)和一般线性模型(GLM)确定影响土壤质量的关键因素。[结果]植被恢复后相较于无林地,土壤容重、砂粒含量下降,而有机质、全氮、全钾、速效氮、速效钾等土壤养分含量增加。筛选出的研究区土壤质量评价MDS指标为全氮、砂粒、全钾、pH、有效含水量。4种方法(SQI-LT、SQI-NLT、SQI-LM、SQI-NLM)下,不同植被恢复类型的SQI值排序均为落叶阔叶混交林>侧柏针阔混交林>油松纯林>油松针阔混交林>侧柏油松混交林>侧柏纯林>无林地,植被恢复后土壤质量显著提升。SQI-NLM的土壤质量评价方法在北京山区具有更好的适用性。相较于无林地,其他植被恢复类型的SQI-NLM分别提高64%,48%,45%,36%,33%,27%。GLM模型解释了土壤质量指数总变异的85.24%,植被类型对土壤质量指数的解释比例最大(45.09%)。[结论]选择适宜的植被恢复类型是改善区域土壤质量的关键。未来实施植被恢复时,树种选择上优先考虑阔叶树种。造林配置方式的选择应取决于树种而定,如侧柏纯林中引入本土阔叶树种形成侧柏针阔混交林或选择油松纯林是最佳造林模式。

基于机器学习模型的高植被覆盖区浅层滑坡预测

为探究高植被覆盖区浅层滑坡的影响因素并构建最优的滑坡预测模型,该研究以华蓥市山区林地为研究对象,考虑了蓄积量、林分密度、平均树龄、林分类型和红绿植被指数(green-red vegetation index,GRVI)等植被因子,并结合地形地质因素,经过Boruta重要性分析以及共线性诊断,利用Logistic回归模型、广义相加模型、随机森林模型、支持向量机模型和人工神经网络模型等5种机器学习模型构建华蓥市山区林地浅层滑坡预测模型,并结合历史滑坡点检验,提出华蓥市山区林地浅层滑坡的最佳预测模型及高易发性区域的植被特征。结果表明:1)工程地质岩组、距河流距离、距断层距离、林分类型、平均树龄和蓄积量是影响浅层滑坡的主要因子;2)不同因子组合对模型精度有极大的影响,考虑蓄积量、林分密度、平均树龄等植被因子有利于提高模型的预测精度;3)在5种模型中,预测精度最高的模型为随机森林模型,精度可达到95.05%;4)研究区高易发性及以上区域的面积为25.31 km^(2),占研究区总面积的14.79%,低密度(1000~1500株/hm^(2))、高蓄积量(>80 m3/hm^(2))和高树龄(>30 a)是浅层滑坡发生的主要植被特征。该研究结果可为中国高植被覆盖区极端暴雨型滑坡的预警与防控提供科学决策和技术支撑。

HIV阳性与HIV阴性猴痘患者临床特征分析

目的分析人HIV阳性与HIV阴性猴痘患者的临床和影像特征,为临床诊疗提供参考。方法回顾性分析2023年6月1日至11月30日首都医科大学附属北京佑安医院收治住院的36例确诊猴痘患者的临床和影像资料,按照是否合并HIV感染分为HIV阳性组和HIV阴性组。观察比较两组人群临床和影像特征。结果36例猴痘患者均为男性且为男男性行为者(men who have sex with men,MSM),平均年龄(31.5±6.4)岁;HIV阳性组28例,HIV阴性组8例。主要表现为皮疹、发热、淋巴结肿大。皮疹的首发部位(24例,66.7%)和最主要的分布部位(30例,83.3%)均为生殖器和肛门,以丘疹和脓疱疹为主。合并其他性传播性疾病14例(38.9%,14/36);合并细菌感染21例(58.3%,21/36),主要为皮肤软组织感染和肛周感染。影像检查结果异常者均为HIV阳性组患者。4例(11.1%,4/36)肺炎CT表现以磨玻璃影、实变、多发结节为主;2例并发肠梗阻,影像表现以胃肠道扩张为主,2例直肠炎表现为直肠壁增厚,肠腔狭窄。两组患者的流行病学资料、临床特征、皮疹分布及性质和实验室检查结果比较差异均无统计学意义(P>0.05)。结论36例猴痘患者以青壮年MSM人群为主,且多为HIV感染者;生殖器和肛周是皮疹首发和最多发部位,溃疡样皮疹仅见于HIV感染者;轻症患者预后良好,重症患者可合并细菌性感染、肠梗阻和直肠炎。并发肺炎者CT主要表现为实变和磨玻璃影,并可见两肺多发、随机分布的实性结节。

不同类型侧柏人工林下优势草本生态位及种间关系研究

探究北京山区不同类型侧柏人工林下优势草本的生态位和种间关联性,为京津风沙源工程人工林营造与管理提供参考,本研究以侧柏(Platycladus orientalis)纯林(C1)、侧柏-油松(Pinus tabuliformis)混交林(C2)和侧柏-黄栌(Cotinus coggygria var.cinereus)混交林(C3)为研究对象,对不同类型林下优势草本生态位宽度、生态位重叠度、总体关联性和种间联结性进行研究。结果表明:生态位宽度排序与重要值排序无显著定性关系;茜草(Rubia cordifolia)是3种林分类型共有的优势草本,与其他草本的生态位重叠程度大于0.90;总体关联性检验表明,C2为显著正关联,C3为显著负关联,C1为不显著正关联;此外,C2林下优势草本种间正联结性强,而C3林下优势草本种间负联结强。黄花蒿(Artemisia annua)-唐松草(Thalictrum aquilegiifolium var.sibiricum)、茜草-萝藦(Cynanchum rostellatum)等种对联结性强、生态位重叠值大,在北京山区侧柏人工林下具有较强的生境适应性。

藏东-川西生态维护水源涵养区产水量驱动机制

藏东-川西生态维护水源涵养区位于西南高山峡谷区北部,是中国典型的生态脆弱区,生态系统抗干扰能力差,对气候变化的反应敏感。产水量是生态系统服务中的一项重要功能,研究产水量空间分布特征及其影响因子对该地区水资源保护、涵养,开发和利用有重要意义。基于2000—2020年地表覆盖产品、气候、基岩深度、土壤和地形等数据,运用InVEST模型Annual Water Yield模块模拟了藏东-川西地区产水量;结合地理探测器(GDM)分析了造成产水量空间分异的各因子的解释能力;对q>0.1的因子引入多尺度地理加权回归(MGWR)分析它们对研究区不同地理位置产水量的影响程度,并运用Theil-Sen趋势分析、Mann-Kendall显著性检验得到了产水量及其主导因素时空变化特征;同时利用Hurst指数预测了未来短期内产水量上升或下降趋势和评估了研究时段内产水量在不同空间位置的波动水平。结果表明:1)降水量和产水量空间分布在研究区内呈现“东西高,中部低”的分布格局,岷江流域降水量为最大,金沙江流域蒸散水平最高,怒江流域产水量领先其余三个流域;2)除降水量和蒸散发外,藏东-川西地区产水量主要影响因子有气候因子(年均湿度和年均风速)、地形因子(高程)、土壤类型、植被因子(归一化植被指数和净初级生产力)与社会因子(地表覆盖类型和人类活动强度指数);其中降水量、蒸散发、高程、归一化植被指数、净初级生产力和地表覆盖类型是产水量的主导影响因素。3)降水、高程与人类活动强度指数对产水服务的影响有较强的正向作用,而蒸散发、归一化植被指数和净初级生产力展现出较强的负向作用。4)研究区南部区域产水量波动水平高。在未来短期内,研究区95.30%的区域有下降趋势。5)藏东-川西地区不应将盲目提升人工植被覆盖度作为提高产水量首要方案,应注意对天然林的保护和预防石漠化。

西南高山峡谷区水力侵蚀时空变化及其驱动力

[目的]确定西南高山峡谷区水力侵蚀的空间分布及其时空变化特征,探究区域水力侵蚀的驱动机制,并为区域水土流失治理提供对策。[方法]基于GIS和RUSLE模型,利用Sen趋势分析和Mann-Kendall显著性检验法、随机森林回归对西南高山峡谷区水力侵蚀的时空演变特征以及驱动力进行分析。[结果](1)西南高山峡谷区水力侵蚀微度和轻度侵蚀占比78.05%以上。(2)整体上,2000—2020年水力侵蚀量变化范围为4.606 3×10^(8)~1.487 4×10^(9) t,多年均值为7.966 4×10^(8) t。降雨侵蚀力因子变化范围为125.11~249.93 MJ·mm/(hm^(2)·h·a),多年均值为186.71 MJ·mm/(hm^(2)·h·a)。植被覆盖与管理因子变化范围为0.37~0.70,多年均值为0.48。(3)整体上坡度坡长因子对西南高山峡谷区水力侵蚀空间分异的解释程度最高,达到41%,其次是植被覆盖与管理因子,达到24%,其余是降雨侵蚀力因子>土壤可蚀性因子>水土保持措施因子,分别达到16%,12%,8%,且各因子对水力侵蚀空间分异的解释程度随着水土保持分区的不同而出现差异。[结论]西南高山峡谷区侵蚀严重的区域主要分布于藏东—川西高山峡谷生态维护水源涵养区南部,藏东南高寒高山峡谷生态维护区西北部、东部。坡度坡长因子及植被覆盖管理因子是西南高山峡谷区水力侵蚀空间分布的主要驱动因素。藏东—川西高山峡谷生态维护水源涵养区、藏东南高寒高山峡谷生态维护区和滇西北高山峡谷生态维护区,建议改善此区域植被覆盖,提高土壤抵抗侵蚀能力;滇北—川西南高山峡谷蓄水保土区建议在改善植被覆盖的基础上,在生态脆弱的区域布置适当水土保持措施。

磁共振质子密度脂肪分数在非酒精性脂肪性肝病诊断中的应用现状

非酒精性脂肪性肝病(non-alcoholic fatty liver disease,NAFLD)已成为我国乃至全球慢性肝病的主要病因,包括非酒精性脂肪肝(non-alcoholic fatty liver,NAFL)、非酒精性脂肪性肝炎(non-alcoholic steatohepatitis,NASH)和肝硬化,最终发展为肝细胞癌(hepatocellular carcinoma,HCC)。早期诊断NAFLD对预防肝脏相关疾病的进展及相关并发症有重要的临床意义。肝脏脂肪变性作为NAFLD的一个基本组织学特征,准确评估和量化肝脏脂肪尤为重要,磁共振测量的质子密度脂肪分数作为无创性定量诊断肝脏脂肪的影像学方法,可以帮助临床医师及时诊断及治疗。本文对质子密度脂肪分数在NAFLD诊断中的研究进展作一综述。

基于最大熵模型的华蓥山林地浅表层滑坡风险析因

【目的】确定环境变量对林地浅表层滑坡风险预测的相对贡献率,明确影响浅表层滑坡风险的关键植被因素及其减灾区间,探明植被因素与非植被因素对浅表层滑坡风险的耦合效应,为林地浅表层滑坡风险评价和减灾决策制定提供科学依据。【方法】以华蓥山林地为研究对象,选取17个浅表层滑坡影响因子,采用最大熵模型进行林地浅表层滑坡风险模拟,输出各因子对林地浅表层滑坡风险预测的相对贡献率,对比分析考虑或不考虑植被因素条件下林地浅表层滑坡风险对各因子的响应变化。【结果】1)模型精度受试者工作特征曲线检验结果显示,不考虑植被因素的情况下,模型模拟精度为0.887,达到很准确的精度水平;考虑植被因素的情况下,模型模拟精度提升3.1%,为0.915,达到极准确的精度水平。2)工程地质岩组、蓄积量、距断层距离、地形起伏度、高程、绿色比值植被指数、平面曲率和林分类型8个因子对浅表层滑坡风险预测的累计贡献率达80%,其中植被因素对林地浅表层滑坡风险预测具有重要作用,主要体现在蓄积量、植被覆盖度和林分类型3方面。3)植被因素的存在造成浅表层滑坡风险对平面曲率、坡向、高程变异系数、坡度变率和坡面曲率5个变量的响应发生变化:对平面曲率、高程变异系数和剖面曲率所产生的浅表层滑坡风险起削弱作用,削减幅度分别为4.9%、5.9%和8.1%;对坡度变率所产生的浅表层滑坡风险起加剧作用,加剧幅度为10.9%;对坡向所产生的浅表层滑坡风险具有正反2方面作用,加剧和削减幅度分别为12.8%和6.4%。【结论】MaxEnt模型用于林地浅表层滑坡风险模拟具有较高模拟精度,能够直观表达浅表层滑坡风险对各影响因子的响应;利用MaxEnt模型预测林地浅表层滑坡风险时,除了地质、地形、地貌、土壤等常规影响因素外,植被因素也是关键环境变量,其对模拟精度具有重要贡献;植被因素的存在整体上不改变浅表层滑坡风险对其他影响因子的响应趋势,但对于某些非植被因素的极端值所产生的浅表层滑坡风险具有重要影响,呈现出耦合效应,既可能加剧也可能削弱浅表层滑坡风险。

Hydrophobic CHA-ZIFs with a junctional trap between cha and d6r cages for adsorption of 2,3-butanediol in aqueous solution

The adsorption and separation of diols from dilute aqueous solution using hydrophobic materials is very challenging due to the strong diol-water hydrogen-bonding interactions. Herein, we screened hydrophobic zeolitic imidazolate frameworks(ZIFs) with chabazite(CHA) topology for separation of 2,3-butanediol(2,3-BDO) and 1,3-propanediol(1,3-PDO), which had junctional and hydrophobic traps matching the two end methyl groups of the 2,3-BDO molecule. Based on CHA-ZIFs with the same small-sized ligand 2-methylimidazole(mIm) and different large-sized ligand benzimidazole derivatives(RbIm),CHA-ZIFs with larger surface areas were obtained by the addition of excess small-sized ligand mIm in the synthesis process. We showed that all of the hydrophobic CHA-ZIFs preferentially adsorbed 2,3-BDO over 1,3-PDO by static batch adsorption and dynamic column adsorption experiments. But ZIF-301 and ZIF-300 with halogen groups exhibited better adsorptive separation performance for 2,3-BDO/1,3-PDO than ZIF-302 with methyl groups. For a typical ZIF-301, its adsorption capacity for 2,3-BDO was 116.4 mg·g^(-1)and selectivity for 2,3-BDO/1,3-PDO was 3.8 in dynamic column adsorption of the binary-component system(2,3-BDO/1,3-PDO: 50 g·L^(-1)/50 g·L^(-1)). Computational simulations revealed that 2,3-BDO preferentially adsorbed in a trap at the junction between the cha and d6r cages of CHA-ZIFs,meaning the strong host-guest interactions. Therefore, the hydrophobic CHA-ZIFs with a junctional trap were promising candidate materials for adsorbing 2,3-BDO, which also provided a new perspective for separating diols in dilute aqueous solutions.

Coupled effects of climate change and human activities on vegetation dynamics in the Southwestern Alpine Canyon Region of China

The driving effects of climate change and human activities on vegetation change have always been a focal point of research.However,the coupling mechanisms of these driving factors across different temporal and spatial scales remain controversial.The Southwestern Alpine Canyon Region of China(SACR),as an ecologically fragile area,is highly sensitive to the impacts of climate change and human activities.This study constructed a vegetation cover dataset for the SACR based on the Enhanced Vegetation Index(EVI)from 2000 to 2020.Spatial autocorrelation,Theil-Sen trend,and Mann-Kendall tests were used to analyze the spatiotemporal characteristics of vegetation cover changes.The main drivers of spatial heterogeneity in vegetation cover were identified using the optimal parameter geographic detector,and an improved residual analysis model was employed to quantify the relative contributions of climate change and human activities to interannual vegetation cover changes.The main findings are as follows:Spatially,vegetation cover exceeds 60%in most areas,especially in the southern part of the study area.However,the border area between Linzhi and Changdu exhibits lower vegetation cover.Climate factors are the primary drivers of spatial heterogeneity in vegetation cover,with temperature having the most significant influence,as indicated by its q-value,which far exceeds that of other factors.Additionally,the interaction q-value between the two factors significantly increases,showing a relationship of bivariate enhancement and nonlinear enhancement.In terms of temporal changes,vegetation cover shows an overall improving trend from 2000 to 2020,with significant increases observed in 68.93%of the study area.Among these,human activities are the main factors driving vegetation cover change,with a relative contribution rate of 41.31%,while climate change and residual factors contribute 35.66%and 23.53%,respectively.By thoroughly exploring the coupled mechanisms of vegetation change,this study provides important references for the sustainable management and conservation of the vegetation ecosystem in the SACR.

Recent advances in living cell nucleic acid probes based on nanomaterials for early cancer diagnosis

The early diagnosis of cancer is vital for effective treatment and improved prognosis. Tumor biomarkers, which can be used for the early diagnosis, treatment, and prognostic evaluation of cancer, have emerged as a topic of intense research interest in recent years. Nucleic acid, as a type of tumor biomarker, contains vital genetic information, which is of great significance for the occurrence and development of cancer. Currently, living cell nucleic acid probes, which enable the in situ imaging and dynamic monitoring of nucleic acids, have become a rapidly developing field. This review focuses on living cell nucleic acid probes that can be used for the early diagnosis of tumors. We describe the fundamental design of the probe in terms of three units and focus on the roles of different nanomaterials in probe delivery.

北京山区针阔混交林地土壤有机碳含量的影响因素研究

探究生物因子和非生物因子与土壤有机碳含量的关系,解析影响土壤有机碳含量变异的主导因素,可为生态系统碳平衡协调发展提供理论依据。以北京山区针阔混交林为研究对象,基于64个样地的实测数据,采用结构方程模型筛选出影响土层(0-10、10-20、20-30 cm)有机碳含量的主导因素,并结合结构方程模型探究了各因子对土壤有机碳含量的直接和间接影响。结果表明,(1)林龄、根系生物量、凋落物质量、土壤全氮和土壤容重对0-10 cm的土壤有机碳含量的影响极显著(P<0.01),植物多样性对0-10 cm的土壤有机碳含量影响显著(P<0.05);直接效应依次为土壤全氮(0.73)>根系生物量(0.59)>凋落物质量(0.56)>林龄(0.47)>土壤容重(-0.44)>物种香农维纳指数(0.21),间接效应依次为林龄(0.31)>根系生物量(0.29)>凋落物质量(0.27)>物种香农维纳指数(0.11)。(2)海拔、土壤全氮和土壤容重对10-20 cm的土壤有机碳含量影响极显著(P<0.01),根系生物量、林龄对10-20 cm的土壤有机碳含量影响显著(P<0.05);直接效应依次为土壤全氮(0.69)>土壤容重(-0.53)>海拔(0.32)>根系生物量(0.27)>林龄(0.24),间接效应依次为海拔(0.23)>林龄(0.14)>根系生物量(0.09)。(3)海拔、土壤全氮和土壤容重对20-30 cm的土壤有机碳含量影响极显著(P<0.01),pH值对20-30 cm的土壤有机碳含量影响显著(P<0.05);直接效应依次为土壤全氮(0.59)>土壤容重(-0.47)>海拔(0.43)>pH值(-0.15),间接效应依次为海拔(0.14)>pH值(-0.04)。综上,土壤全氮和土壤容重主要通过直接作用影响土壤有机碳含量,而根系生物量、凋落物质量、林龄、植物多样性、土壤pH值对土壤有机碳含量不仅存在直接影响,而且还通过其他因子的作用而产生间接影响。

2000—2019年西南高山峡谷区植被变化对气候变化和人类活动的响应

为了探究中国典型生态环境脆弱区——西南高山峡谷区植被变化对气候变化和人类活动的响应规律,量化气候变化和人类活动的相对贡献,该研究基于2000—2019年归一化差异植被指数(normalized difference vegetation index,NDVI)数据集,采用Theil-Sen趋势分析、Mann-Kendall显著性检验和Hurst指数分析了NDVI时空变化特征及未来变化趋势;在此基础上结合气象因子数据集,采用相关性分析和残差分析探讨了NDVI对气候变化和人类活动的响应。结果表明:1)时间尺度上,2000—2019年NDVI总体表现为波动上升趋势,增长速率为0.0046/a。空间尺度上,NDVI呈上升趋势区域面积占研究区总面积85.59%,植被恢复效果明显,且未来NDVI变化还将以上升趋势为主。2)在区域气候暖干化的背景下,NDVI对不同气候因子的响应有所差异,总体上NDVI与气温和太阳辐射呈正相关,而与降雨量呈负相关,气温对NDVI变化的影响力要强于太阳辐射和降雨量,是影响NDVI变化的主要气候因子。3)85.10%区域面积的植被变化受人类活动和气候变化的共同影响,其中人类活动是植被变化的主要驱动因素,气候变化为次要驱动因素,相对贡献率分别为68.67%和31.33%。该研究结果可为西南高山峡谷区未来生态环境建设提供科学依据,助力区域绿色可持续发展目标的实现。

南渡江流域降雨侵蚀力时空分布与变化趋势研究

降雨侵蚀力是表征降雨侵蚀强度的重要指标,对研究区域水土流失潜在风险以及土壤侵蚀模型预测具有重要意义。为分析南渡江流域降雨侵蚀力时空变化趋势,基于日降雨侵蚀力模型,利用流域及其周边13个气象站1971—2020年逐日降雨数据,采用Mann-Kendall非参数趋势/突变检验、小波分析和反距离加权插值等方法在不同时空尺度上对降雨侵蚀力进行研究,从而确定降雨侵蚀力的时间和空间变化趋势。结果表明,南渡江流域1971—2020年年均降雨侵蚀力范围为1184133~2369214 MJ·mm·hm-2·h-1,均值为1649767 MJ·mm·hm-2·h-1,年际变化整体呈现波动上升趋势,年降雨侵蚀力存在周期性变化,未发生显著性突变;降雨侵蚀力年内分布集中在7—9月,因此需加强期间水土流失防治工作。季节的年际变化除春季降雨侵蚀力呈现下降趋势外,夏季、秋季和冬季均呈上升趋势;降雨侵蚀力空间分布呈现从南向北逐渐降低的趋势,各气象站变异系数范围为024~043,由北向南逐步递减,具有较高的区域变异性;南渡江流域降雨侵蚀力与侵蚀性降雨量相关性最高,其后依次为海拔和纬度。研究成果可为南渡江流域及其典型侵蚀区水土保持和环境治理提供科学参考。

基于L-XGB算法的岩爆倾向等级预测模型

为解决岩爆预测复杂性、特殊性、随机性特征导致样本要求高、预测精度低的缺点,基于LOF(局部离群因子检测方法)结合XGBoost(极限梯度提升树)方法,通过网格搜索和曲线搜索拟合内部学习参数,构建L-XGB岩爆趋势预测模型。使用国内外260组岩爆实例数据对模型预测结果进行验证,与XGBoost、随机森林、KNN和支持向量机算法的预测结果进行对比分析研究。研究结果表明:该模型预测率94.2%,为岩爆预测提供了更加合理可靠的预测模型。研究结果可为岩爆预测提供方法以及岩爆的事前风险管理与防治提供理论基础。

The Solar Upper Transition Region Imager(SUTRI)Onboard the SATech-01 Satellite

The Solar Upper Transition Region Imager(SUTRI)onboard the Space Advanced Technology demonstration satellite(SATech-01),which was launched to a Sun-synchronous orbit at a height of~500 km in 2022 July,aims to test the on-orbit performance of our newly developed Sc/Si multi-layer reflecting mirror and the 2k×2k EUV CMOS imaging camera and to take full-disk solar images at the Ne VII 46.5 nm spectral line with a filter width of~3 nm.SUTRI employs a Ritchey-Chrétien optical system with an aperture of 18 cm.The on-orbit observations show that SUTRI images have a field of view of~416×416 and a moderate spatial resolution of~8″without an image stabilization system.The normal cadence of SUTRI images is 30 s and the solar observation time is about16 hr each day because the earth eclipse time accounts for about 1/3 of SATech-01's orbit period.Approximately15 GB data is acquired each day and made available online after processing.SUTRI images are valuable as the Ne VII 46.5 nm line is formed at a temperature regime of~0.5 MK in the solar atmosphere,which has rarely been sampled by existing solar imagers.SUTRI observations will establish connections between structures in the lower solar atmosphere and corona,and advance our understanding of various types of solar activity such as flares,filament eruptions,coronal jets and coronal mass ejections.

艾滋病合并进行性多灶性脑白质病的MRI表现

目的探讨艾滋病合并进行性多灶性脑白质病(PML)的MRI特征,以期提升对其诊断及鉴别诊断的水平。方法回顾分析2015年5月至2022年3月在首都医科大学附属北京佑安医院经病理证实或临床确诊的27例艾滋病合并PML患者资料,总结分析其MRI表现。结果艾滋病合并PML患者共27例,均为男性,平均年龄(38±9)岁。27例患者MRI表现为皮质下多发病灶,其中26例(96.3%)为不对称分布,累及脑皮质者1例(3.7%)。幕上病灶23例(85.19%)、幕下病灶14例(51.85%)、同时受累10例(37.04%)。幕上病灶主要位于顶叶18例(66.67%)、额叶17例(62.96%)、颞叶12例(44.44%)、枕叶6例(22.22%)、胼胝体压部3例(11.11%),幕上受累病例均为多叶受累。幕下病灶,小脑受累8例(29.63%)、脑桥4例(14.81%)、延髓3例(11.11%)和桥臂2例(7.41%)。T2WI上显示为“银河征”或“扇贝征”18例(66.67%),DWI上病灶边缘高信号17例(62.96%);27例均无占位效应;脑萎缩2例(7.41%);MRI增强扫描19例,仅1例(5.26%)强化,呈点状、线样强化。结论艾滋病合并PML以双侧额叶、顶叶、枕叶皮质下多发及不对称的脱髓鞘病变多见,特征性的表现为T2WI上“银河征”,病变的分布范围与脑血管的分布区不一致,DWI上病灶边缘为高信号,无占位效应,增强多无强化。因此,MRI检查结合患者临床病史、体征及实验室检查,可显著提升其诊断的正确率。

Reversible cationic-anionic redox in disordered rocksalt cathodes enabled by fluorination-induced integrated structure design

Cation-disordered rocksalt oxides(DRX)have been identified as promising cathode materials for high energy density applications owing to their variable elemental composition and cationic-anionic redox activity.However,their practical implementation has been impeded by unwanted phenomena such as irrepressible transition metal migration/dissolution and O_(2)/CO_(2)evolution,which arise due to parasitic reactions and densification-degradation mechanisms during extended cycling.To address these issues,a micron-sized DRX cathode Li_(1.2)Ni_(1/3)Ti_(1/3)W_(2/15)O_(1.85)F_(0.15)(SLNTWOF)with F substitution and ultrathin LiF coating layer is developed by alcohols assisted sol-gel method.Within this fluorination-induced integrated structure design(FISD)strategy,in-situ F substitution modifies the activity/reversibility of the cationic-anionic redox reaction,while the ultrathin LiF coating and single-crystal structure synergistically mitigate the cathode/electrolyte parasitic reaction and densification-degradation mechanism.Attributed to the multiple modifications and size effect in the FISD strategy,the SLNTWOF sample exhibits reversible cationic-anionic redox chemistry with a meliorated reversible capacity of 290.3 mA h g^(-1)at 0.05C(1C=200 mA g^(-1)),improved cycling stability of 78.5%capacity retention after 50 cycles at 0.5 C,and modified rate capability of 102.8 mA h g^(-1)at 2 C.This work reveals that the synergistic effects between bulk structure modification,surface regulation,and engineering particle size can effectively modulate the distribution and evolution of cationic-anionic redox activities in DRX cathodes.

Design,Fabrication and Assembly of the Solar Upper Transition Region Imager(SUTRI)

The Solar Upper Transition Region Imager(SUTRI)focuses on the solar transition region to achieve dynamic imaging observation of the upper transition region.In this paper,we report the optical system design,mechanical design,ultrasmooth mirror manufacture and measurement,EUV multilayer film coating,prelaunch installation and calibration for the SUTRI payload at IPOE,Tongji University.Finally,the SUTRI carried by the SATech-01 satellite was successfully set to launch.All functions of this telescope were normal,and the observation results obtained in orbit were consistent with the design.

Huangqi Guizhi Wuwu Decoction suppresses inflammation and bone destruction in collagen-induced arthritis mice

Objective: Rheumatoid arthritis(RA) is a chronic inflammatory and destructive arthritis, characterized by inflammatory infiltration and bone destruction. Huangqi Guizhi Wuwu Decoction(HGWD) is traditional Chinese medicine, which has been applied in the treatment of RA in clinical. The aim of this study was to investigate the therapeutic effect of HGWD on collagen-induced arthritis(CIA) mouse model.Methods: DBA/1J female mice were used to establish the collagen-induced arthritis(CIA) model. HGWD was administered intragastrically once a day for four weeks starting on the 22nd day after the first immunization. The body weight, hind paw thickness and clinical score were measured every five days. Gait analysis, histopathological staining, enzyme-linked immunosorbent assay(ELISA), ultrasound imaging and micro-computed tomography imaging were performed to determine the effects of HGWD treatment on inflammation and bone structure in this model. Moreover, Real-time PCR and Western blot analysis were used to detect inflammatory factors m RNA and protein levels after HGWD intervention in RAW264.7 cells.Results: HGWD attenuated symptoms of arthritis, suppressed inflammatory synovium area and the serum levels of inflammatory factors, inhibited joint space enlargement in the knee and ankle joints,reduced numbers of osteoclasts, protected bone destruction, as well as improved motor function.HGWD decreased the expression of m RNA for inflammatory factors and the protein expression levels of p-NF-ΚB and IL-17.Conclusion: These results suggested that HGWD suppresses inflammation, attenuates bone erosion and maintains motor function in collagen-induced arthritis mice.