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高黎贡山南段昆虫病原真菌物种多样性及影响因素
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作者 陈自宏 张翼飞 +2 位作者 陈凯 陈见影 徐玲 《生物多样性》 北大核心 2025年第1期43-56,共14页
高黎贡山南段立体气候明显、生境复杂多样,生物多样性较高,但目前对其昆虫病原真菌资源的关注较少。为了解高黎贡山南段昆虫病原真菌的物种多样性及分布格局,本研究在该区域不同海拔生境中进行了昆虫病原真菌资源的调查。于2019–2021... 高黎贡山南段立体气候明显、生境复杂多样,生物多样性较高,但目前对其昆虫病原真菌资源的关注较少。为了解高黎贡山南段昆虫病原真菌的物种多样性及分布格局,本研究在该区域不同海拔生境中进行了昆虫病原真菌资源的调查。于2019–2021年在该区域沿海拔(700–3,100 m)梯度每上升100 m设置样地,采集土样和受感染昆虫标本,分离昆虫病原真菌菌株和鉴定物种;将样区分为5个海拔段(Ⅰ–Ⅴ),用α多样性分析昆虫病原真菌的物种多样性和分布特征,用β多样性分析其群落结构,通过Pearson相关性和冗余分析(redundancyanalysis,RDA)分析生境生态因子对其物种多样性的影响。结果表明,从高黎贡山南段共获得昆虫病原真菌菌株2,175株,隶属于5科20属78种,其中从土壤样品中获得24种1,331株昆虫病原真菌,从昆虫样品中获得66种844株昆虫病原真菌。中海拔段Ⅲ(中山湿性常绿阔叶林)中昆虫病原真菌物种丰富度(49种)和菌株数(766株)最高;中海拔段Ⅱ(亚热带雨林)和Ⅲ的Shannon-Wiener多样性指数(分别为2.686和2.677)和Simpson多样性指数(分别为0.884和0.876)最高;高海拔段V的Simpson优势度指数(0.615)最高;低海拔段Ⅰ(干热河谷)的Pielou均匀度指数(0.790)最高。海拔对两种来源(土壤和昆虫)的昆虫病原真菌物种多样性均有显著影响;来自土壤的昆虫病原真菌受土壤温度的影响较大,而来自昆虫的昆虫病原真菌受空气湿度的影响较大;土壤pH值对该区域昆虫病原真菌多样性的影响较小。研究结果表明,高黎贡山南段的昆虫病原真菌资源丰富,广泛分布于各海拔段。 展开更多
关键词 高黎贡山 昆虫病原真菌 海拔段 物种多样性 生态因素
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Chaetarthria chenjuni Jia & Yang, sp. nov.(Coleoptera: Hydrophilidae), a new species from China and additional faunistic records
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作者 Fenglong Jia Zhenming Yang +2 位作者 Lu Jiang kai chen Shujiao Jiang 《Zoological Systematics》 CSCD 2020年第2期146-149,共4页
A new species of Chaetarthria Stephens,1835,is described from China,namely Chaetarthria chenjuni Jia&Yang,sp.nov.from Hainan,Guangdong and Guangxi Provinces,China.It is unique in the C.indica group by having the d... A new species of Chaetarthria Stephens,1835,is described from China,namely Chaetarthria chenjuni Jia&Yang,sp.nov.from Hainan,Guangdong and Guangxi Provinces,China.It is unique in the C.indica group by having the distinct punctures,as strong as those of puncture series,on the elytra.The broad median lobe of aedeagus has a round apex,which can be used to separate it easily from other known species occurring in the Oriental Region. 展开更多
关键词 Chaetarthria HYDROPHILIDAE COLEOPTERA FAUNA China
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跨境电商改革何以影响供应链效率——来自综试区政策的经验证据 被引量:3
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作者 罗奇 陈凯 +1 位作者 张学思 何小钢 《经济学报》 2025年第1期190-208,共19页
作为承载“互联网+外贸”的贸易新业态,跨境电商在提升供应链效率、保障供应链安全方面的重要性日益凸显。本文将跨境电商综合试验区政策作为准自然实验,采用2008—2021年中国上市企业数据和渐进双重差分方法,基于存货视角系统考察了跨... 作为承载“互联网+外贸”的贸易新业态,跨境电商在提升供应链效率、保障供应链安全方面的重要性日益凸显。本文将跨境电商综合试验区政策作为准自然实验,采用2008—2021年中国上市企业数据和渐进双重差分方法,基于存货视角系统考察了跨境电商改革对供应链效率的影响。研究发现:跨境电商改革能够显著提高企业存货周转率,进而提升供应链效率,该结论在考虑一系列可能干扰估计结果的因素后仍然成立;跨境电商改革提升供应链效率的作用渠道主要包括助力企业拓展海外市场、降低需求不确定性以及推动制造业与服务业融合;此外,地区信息基础设施建设和制度环境改善进一步强化了跨境电商改革对供应链效率的提升作用。在当前中国大力建设跨境电商综合试验区背景下,本文研究结论对于如何提升供应链现代化水平提供了政策启示。 展开更多
关键词 跨境电商 供应链效率 存货周转率 上市企业
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Deciphering environmental factors influencing phytoplankton community structure in a polluted urban river 被引量:3
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作者 Xiaxia Li kai chen +7 位作者 Chao Wang Tianyu Zhuo Hongtao Li Yong Wu Xiaohui Lei Ming Li Bin chen Beibei Chai 《Journal of Environmental Sciences》 2025年第2期375-386,共12页
Tuojiang River Basin is a first-class tributary of the upper reaches of the Yangtze River—which is the longest river in China.As phytoplankton are sensitive indicators of trophic changes inwater bodies,characterizing... Tuojiang River Basin is a first-class tributary of the upper reaches of the Yangtze River—which is the longest river in China.As phytoplankton are sensitive indicators of trophic changes inwater bodies,characterizing phytoplankton communities and their growth influencing factors in polluted urban rivers can provide new ideas for pollution control.Here,we used direct microscopic count and environmental DNA(eDNA)metabarcoding methods to investigate phytoplankton community structure in Tuojiang River Basin(Chengdu,Sichuan Province,China).The association between phytoplankton community structure and water environmental factors was evaluated by Mantel analysis.Additional environmental monitoring data were used to pinpoint major factors that influenced phytoplankton growth based on structural equation modeling.At the phylum level,the dominant phytoplankton taxa identified by the conventional microscopic method mainly belonged to Bacillariophyta,Chlorophyta,and Cyanophyta,in contrast with Chlorophyta,Dinophyceae,and Bacillariophyta identified by eDNA metabarcoding.Inα-diversity analysis,eDNA metabarcoding detected greater species diversity and achieved higher precision than the microscopic method.Phytoplankton growth was largely limited by phosphorus based on the nitrogen-to-phosphorus ratios>16:1 in all water samples.Redundancy analysis and structural equation modeling also confirmed that the nitrogen-to-phosphorus ratio was the principal factor influencing phytoplankton growth.The results could be useful for implementing comprehensive management of the river basin environment.It is recommended to control the discharge of point-and surface-source pollutants and the concentration of dissolved oxygen in areas with excessive nutrients(e.g.,Jianyang-Ziyang).Algae monitoring techniques and removal strategies should be improved in 201 Hospital,Hongrihe Bridge and Colmar Town areas. 展开更多
关键词 Environmental DNA Microscopic count Phytoplankton growth Structural equation modeling Tuojiang River Basin
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Buqi-Tongluo Decoction inhibits osteoclastogenesis and alleviates bone loss in ovariectomized rats by attenuating NFATc1,MAPK,NF-κB signaling 被引量:1
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作者 Yongxian Li Jinbo Yuan +29 位作者 Wei Deng Haishan Li Yuewei Lin Jiamin Yang kai chen Heng Qiu Ziyi Wang Vincent Kuek Dongping Wang Zhen Zhang Bin Mai Yang Shao PanKang Qiuli Qin Jinglan Li Huizhi Guo Yanhuai Ma Danqing Guo Guoye Mo YijingFang Renxiang Tan chenguang Zhan Teng Liu Guoning Gu kai Yuan Yongchao Tang DeLiang Liangliang Xu Jiake Xu Shuncong Zhang 《Chinese Journal of Natural Medicines》 2025年第1期90-101,共12页
Osteoporosis is a prevalent skeletal condition characterized by reduced bone mass and strength,leading to increased fragility.Buqi-Tongluo(BQTL)decoction,a traditional Chinese medicine(TCM)prescription,has yet to be f... Osteoporosis is a prevalent skeletal condition characterized by reduced bone mass and strength,leading to increased fragility.Buqi-Tongluo(BQTL)decoction,a traditional Chinese medicine(TCM)prescription,has yet to be fully evaluated for its potential in treating bone diseases such as osteoporosis.To investigate the mechanism by which BQTL decoction inhibits osteoclast differentiation in vitro and validate these findings through in vivo experiments.We employed MTS assays to assess the potential proliferative or toxic effects of BQTL on bone marrow macrophages(BMMs)at various concentrations.TRAc P experiments were conducted to examine BQTL's impact on osteoclast differentiation.RT-PCR and Western blot analyses were utilized to evaluate the relative expression levels of osteoclast-specific genes and proteins under BQTL stimulation.Finally,in vivo experiments were performed using an osteoporosis model to further validate the in vitro findings.This study revealed that BQTL suppressed receptor activator of NF-κB ligand(RANKL)-induced osteoclastogenesis and osteoclast resorption activity in vitro in a dose-dependent manner without observable cytotoxicity.The inhibitory effects of BQTL on osteoclast formation and function were attributed to the downregulation of NFATc1 and c-fos activity,primarily through attenuation of the MAPK,NF-κB,and Calcineurin signaling pathways.BQTL's inhibitory capacity was further examined in vivo using an ovariectomized(OVX)rat model,demonstrating a strong protective effect against bone loss.BQTL may serve as an effective therapeutic TCM for the treatment of postmenopausal osteoporosis and the alleviation of bone loss induced by estrogen deficiency and related conditions. 展开更多
关键词 OSTEOPOROSIS Estrogen deficiency OSTEOCLAST Buqi-Tongluo NFATc1 MAPK NF-ΚB
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Non-explosive directional fracturing blasting using coal-based solid waste expanding agent 被引量:1
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作者 Quan Zhang Manchao He +7 位作者 Jiong Wang Shan Guo Chao Wang chenjie Hong kai chen Rongzhou Yang Xuepeng Zhang Jianwei Yang 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第6期3691-3710,共20页
Aiming at mitigating the high risks associated with conventional explosive blasting,this study developed a safe directional fracturing technique,i.e.instantaneous expansion with a single fracture(IESF),using a coal-ba... Aiming at mitigating the high risks associated with conventional explosive blasting,this study developed a safe directional fracturing technique,i.e.instantaneous expansion with a single fracture(IESF),using a coal-based solid waste expanding agent.First,the mechanism of directional fracturing blasting by the IESF was analyzed,and the criterion of directional crack initiation was established.On this basis,laboratory experiments and numerical simulations were conducted to systematically evaluate the directional fracturing blasting performance of the IESF.The results indicate that the IESF presents an excellent directional fracturing effect,with average surface undulation differences ranging from 8.1 mm to 22.7 mm on the fracture surfaces.Moreover,during concrete fracturing tests,the stresses and strains in the fracturing direction are measured to be 2.16-3.71 times and 8 times larger than those in the nonfracturing direction,respectively.Finally,the IESF technique was implemented for no-pillar mining with gob-side entry retaining through roof cutting and pressure relief in an underground coal mine.The IESF technique effectively created directional cracks in the roof without causing severe roadway deformation,achieving an average cutting rate and maximum roadway deformation of 94%and 197 mm,respectively.These on-site test results verified its excellent directional rock fracturing performance.The IESF technique,which is safe,efficient,and green,has considerable application prospects in the field of rock mechanics and engineering. 展开更多
关键词 Coal-based solid waste expanding agent Directional fracturing blasting Non-explosive Crack initiation Stress-strain-damage evolution
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调查失业率与奥肯定律再检验——兼谈自然失业率与青年失业问题 被引量:1
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作者 陈恺 申广军 谭韦珊 《经济学报》 2025年第1期19-37,共19页
以往研究发现奥肯定律在中国失效,其重要原因可能是失业率的统计质量。本文使用国家统计局近年来开始发布的城镇调查失业率数据重新验证奥肯定律在中国的有效性。研究表明,采用调查失业率后,奥肯定律在我国成立,且这一结论对不同的替代... 以往研究发现奥肯定律在中国失效,其重要原因可能是失业率的统计质量。本文使用国家统计局近年来开始发布的城镇调查失业率数据重新验证奥肯定律在中国的有效性。研究表明,采用调查失业率后,奥肯定律在我国成立,且这一结论对不同的替代指标和模型设定均稳健。以奥肯定律为理论基础,本文使用状态空间模型和Kalman滤波方法估计得到我国2017年1月至2023年5月的动态自然失业率。对青年劳动力群体的分析显示,2020年后青年调查失业率不断攀升的根源在于自然失业率居高不下。本文研究结论有助于理解我国劳动力市场的结构性特征,更好地实现“稳就业”的政策目标。 展开更多
关键词 调查失业率 奥肯定律 动态自然失业率 青年失业
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Complete response of gallbladder cancer treated with gemcitabine and cisplatin chemotherapy combined with durvalumab:A case report and review of literature
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作者 kai chen Xu Feng +3 位作者 Yuan Shi Xin-Lin Li Zheng-Rong Shi Xiang Lan 《World Journal of Gastrointestinal Oncology》 SCIE 2025年第1期226-232,共7页
BACKGROUND Gallbladder cancer(GBC)is the most common and aggressive subtype of biliary tract cancer(BTC)and has a poor prognosis.A newly developed regimen of gemcitabine,cisplatin,and durvalumab shows promise for the ... BACKGROUND Gallbladder cancer(GBC)is the most common and aggressive subtype of biliary tract cancer(BTC)and has a poor prognosis.A newly developed regimen of gemcitabine,cisplatin,and durvalumab shows promise for the treatment of advanced BTC.However,the efficacy of this treatment for GBC remains unclear.CASE SUMMARY In this report,we present a case in which the triple-drug regimen exhibited marked effectiveness in treating locally advanced GBC,thus leading to a long-term survival benefit.A 68-year-old man was diagnosed with locally advanced GBC,which rendered him ineligible for curative surgery.Following three cycles of therapy,a partial response was observed.After one year of combined therapy,a clinical complete response was successfully achieved.Subsequent maintenance therapy with durvalumab monotherapy resulted in a disease-free survival of 9 months for the patient.The patient experienced tolerable toxicities of reversible grade 2 nausea and fatigue.Tolerable adverse events were observed in the patient throughout the entirety of the treatment.CONCLUSION The combination of gemcitabine and cisplatin chemotherapy with durvalumab was proven to be an effective treatment approach for advanced GBC,with manageable adverse events.Further research is warranted to substantiate the effectiveness of the combined regimen in the context of GBC. 展开更多
关键词 Gallbladder cancer CHEMOTHERAPY IMMUNOTHERAPY Durvalumab Complete response Case report
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光学离焦技术控制近视的研究进展 被引量:31
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作者 陈楠 薛劲松 +6 位作者 蔡江怀 蒋沁 陈凯 颜智鹏 许薇 李新华 杨卫华 《国际眼科杂志》 CAS 北大核心 2022年第2期260-264,共5页
近视是一种常见的眼病,近年来,近视的发生率在全球范围内呈逐年上升趋势,高度近视会增加视力丧失的风险,近视的并发症可引起巨大的经济和社会效益损失。因此,实施控制近视的有效措施至关重要且迫在眉睫。人们对近视的发病机制研究表明,... 近视是一种常见的眼病,近年来,近视的发生率在全球范围内呈逐年上升趋势,高度近视会增加视力丧失的风险,近视的并发症可引起巨大的经济和社会效益损失。因此,实施控制近视的有效措施至关重要且迫在眉睫。人们对近视的发病机制研究表明,周围远视离焦引起眼球轴向伸长不受控制可能是近视发展的机制之一,由此引申的各种光学策略尤其是光学离焦技术控制近视日益成为近视管理主流临床实践的一部分。本文从光学离焦控制近视的原理、离焦性近视动物实验研究、不同光学离焦技术控制近视的最新临床应用等方面进行综述,总结了使用渐进多焦眼镜、周边离焦框架眼镜、多点近视离焦框架眼镜、角膜塑形镜及多焦点软性角膜接触镜控制近视的临床研究结果,拟为延缓近视进展的治疗方案设计提供新的选择。 展开更多
关键词 近视 光学离焦 框架眼镜 角膜接触镜 控制近视
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滇西太保山森林公园子囊菌门虫生真菌物种多样性及其消长动态 被引量:7
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作者 陈自宏 王元兵 +3 位作者 代永东 陈凯 徐玲 何謦成 《生物多样性》 CAS CSCD 北大核心 2019年第9期993-1001,共9页
云南及青藏高原存在着丰富的虫生真菌资源。本文选择云南省保山市省级城市森林公园太保山森林公园为研究区域,对子囊菌门虫生真菌物种多样性及其季节消长动态开展了系统研究。在2016年每月采集土样和罹病昆虫,分离虫生真菌菌株,采用多基... 云南及青藏高原存在着丰富的虫生真菌资源。本文选择云南省保山市省级城市森林公园太保山森林公园为研究区域,对子囊菌门虫生真菌物种多样性及其季节消长动态开展了系统研究。在2016年每月采集土样和罹病昆虫,分离虫生真菌菌株,采用多基因(nrSSU,nrLSU,EF-1α,RPB1和RPB2)系统发育分析进行物种鉴定,通过α多样性分析来研究虫生真菌的数量特征和种群消长动态。太保山森林公园子囊菌门虫生真菌全年均有分布,共获得395个菌株,包括3科9属24种;优势属为虫草属(Cordyceps)(6个种199个菌株),白僵菌属(Beauveria)(5个种80个菌株),优势种依次为Akanthomyces sp.、Cordyceps tenuipes、C.cicadae、C.fumosorosea和Beauveria bassiana。7月菌株检出率最高(85株,占总数的21.4%),8月物种丰富度(15种)和多样性指数(2.35)最高。在5个优势种中,只有Cordyceps cicadae受季节变化影响较大,集中分布于5–9月,7月分布最丰富(35株,占该月菌株总数的41.2%);其他4个种一年大部分时间(11或12个月)都能检测到。结果表明,太保山森林公园子囊菌门虫生真菌资源丰富,多数优势种对季节变化适应能力较强。 展开更多
关键词 太保山森林公园 虫生真菌 物种多样性 优势属种 消长动态
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激光光凝联合雷珠单抗治疗糖尿病性黄斑水肿 被引量:18
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作者 陈凯 周洪伟 《国际眼科杂志》 CAS 北大核心 2019年第9期1598-1601,共4页
目的:比较激光光凝与激光光凝联合雷珠单抗治疗糖尿病性黄斑水肿的疗效。方法:随机对照研究。纳入糖尿病性黄斑水肿患者134例180眼,随机分为试验组和对照组。两组患者年龄、性别、病程、BCVA、IOP、CMT均无差异(P>0.05)。试验组接受... 目的:比较激光光凝与激光光凝联合雷珠单抗治疗糖尿病性黄斑水肿的疗效。方法:随机对照研究。纳入糖尿病性黄斑水肿患者134例180眼,随机分为试验组和对照组。两组患者年龄、性别、病程、BCVA、IOP、CMT均无差异(P>0.05)。试验组接受黄斑格栅光凝联合玻璃体腔注射雷珠单抗,对照组接受黄斑格栅光凝。治疗后1wk,3mo测量两组BCVA、IOP、CMT并进行比较。结果:治疗前、治疗后1wk,3mo,两组IOP比较均无差异(P>0.05)。治疗1wk,3mo,试验组CMT均低于对照组(t=-7.83、-8.80,均P<0.05)。治疗1wk,3mo,试验组BCVA均优于对照组(t=-3.76、-4.09,均P<0.05),治疗1wk试验组BCVA即显著提高(t=1.97,P<0.05)。试验组复发率低于对照组(χ^2=4.59,P=0.032)。两组早期高眼压发生率无差异(χ^2=0.03,P=0.87)。均未出现视网膜脱离、眼内炎。结论:激光光凝联合雷珠单抗比单用激光光凝显著降低术后CMT,并较早提高BCVA,降低复发率。 展开更多
关键词 激光光凝 雷珠单抗 糖尿病性黄斑水肿 最佳矫正视力 眼压 黄斑中心凹厚度
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Characterization of zebrafish alas2 reporter for study on erythropoiesis,blood flow,and erythroid disease
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作者 Wenjuan Zhang Shuang Wu +6 位作者 Yaxin Li Mengye Cao Biao Cao Dantong Li kai chen Jian Zhao Weijun Pan 《Journal of Genetics and Genomics》 2025年第7期958-961,共4页
Erythroid cells, the predominant circulating blood cells, are essential for oxygen and carbon dioxide transport (Obeagu, 2024).Their production, erythropoiesis, involves the coordinated synthesis of globin chains and ... Erythroid cells, the predominant circulating blood cells, are essential for oxygen and carbon dioxide transport (Obeagu, 2024).Their production, erythropoiesis, involves the coordinated synthesis of globin chains and heme molecules to assemble hemoglobin(Zhang et al., 2021). The erythroid-specific enzyme δ-aminolevulinate synthase 2 (ALAS2) is a key rate-limiting factor in heme biosynthesis,with its expression increasing in late-stage erythropoiesis to meet heme demands (Sadlon et al., 1999). Zebrafish (Danio rerio) is a well-established model for studying erythropoiesis due to its genetic tractability and optical transparency (Zhang and Hamza, 2019;Zhang et al., 2021). The Tol2-mediated Gal4-UAS system has been widely applied for gene and enhancer trapping in zebrafish (Asakawa and Kawakami, 2009). However, reliable Gal4 enhancer-trap lines for erythropoiesis remain limited. Here, we report a transgenic zebrafish line with erythroid-specific Gal4FF expression under the control of the endogenous alas2 promoter, offering a more precise erythroblast labeling than the gata1a reporter line. This model provides a valuable tool for erythroid-specific investigations of blood flow dynamics and gene function. 展开更多
关键词 carbon dioxide heme molecules blood flow alas reporter circulating blood cellsare erythroid cellsthe ZEBRAFISH ERYTHROPOIESIS
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Control upconversion decay dynamics from perspective of collective response
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作者 Yingdong Han Yutong Pan +7 位作者 Tong Wei Yu Ma Xingxing Zhang Lei Jiang kai chen Liwei Wu Jiao Cui Chao Gao 《Journal of Rare Earths》 2025年第1期57-63,I0003,共8页
Very recently,upconversion luminescence(UCL)lifetime,as a powerful optical dimension,has attracted tremendous research interest due to its advantages of high information capacity and high photophysical stability.With ... Very recently,upconversion luminescence(UCL)lifetime,as a powerful optical dimension,has attracted tremendous research interest due to its advantages of high information capacity and high photophysical stability.With the implementation and emergence of endlessly fascinating UCL features,it is particularly meaningful to understand the photophysical mechanisms inside UCL materials to enable rational subdivision-level structure design,which is however currently far from sufficient.In this work,we take an ordinary upconversion nanoparticle as an example to prove that the UCL decay curves and corresponding lifetimes are indeed a collective response of the entire UCL system to excitations,that exhibits correlated,yet quite different properties from individual ions.A specially developed theoretical random walk model combined with an experimental lifetime control for Yb^(3+)/Er^(3+)UCL demonstrates that ene rgy diffusion principally alters the decay rate.Moreover,the different extent of the influence of energy diffusion on the emissions of ^(2)H_(11/2)/^(4)S_(3/2)(green)and ^(4)F_(9/2)(red)leads to an extremely uncommon crossover comparison of decay rates.This work provides new ideas for understanding decay dynamics and practical UCL lifetime manipulation methods. 展开更多
关键词 UPCONVERSION LIFETIME Collective response Decaycurves Random walk model Rare earths
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A rock damage model considering shear failure by modified logistic growth theory
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作者 kai chen Roberto Cudmani Andres Peña 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第3期1321-1355,共35页
Localized rock failures,like cracks or shear bands,demand specific attention in modeling for solids and structures.This is due to the uncertainty of conventional continuum-based mechanical models when localized inelas... Localized rock failures,like cracks or shear bands,demand specific attention in modeling for solids and structures.This is due to the uncertainty of conventional continuum-based mechanical models when localized inelastic deformation has emerged.In such scenarios,as macroscopic inelastic reactions are primarily influenced by deformation and microstructural alterations within the localized area,internal variables that signify these microstructural changes should be established within this zone.Thus,localized deformation characteristics of rocks are studied here by the preset angle shear experiment.A method based on shear displacement and shear stress differences is proposed to identify the compaction,yielding,and residual points for enhancing the model's effectiveness and minimizing subjective influences.Next,a mechanical model for the localized shear band is depicted as an elasto-plastic model outlining the stress-displacement relation across both sides of the shear band.Incorporating damage theory and an elasto-plastic model,a proposed damage model is introduced to replicate shear stressdisplacement responses and localized damage evolution in intact rocks experiencing shear failure.Subsequently,a novel nonlinear mathematical model based on modified logistic growth theory is proposed for depicting the shear band's damage evolution pattern.Thereafter,an innovative damage model is proposed to effectively encompass diverse rock material behaviors,including elasticity,plasticity,and softening behaviors.Ultimately,the effects of the preset angles,temperature,normal stresses and the residual shear strength are carefully discussed.This discovery enhances rock research in the proposed damage model,particularly regarding shear failure mode. 展开更多
关键词 Damage model Shear failure LOCALIZATION Shear band Modified growth theory Damage evolution
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Reassessing the phylogenetic relationships of Pseudosorghum and Saccharinae(Poaceae)using plastome and nuclear ribosomal sequences
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作者 kai chen Yan-Chun Liu +5 位作者 Yue Huang Xu-Kun Wu Hai-Ying Ma Hua Peng De-Zhu Li Peng-Fei Ma 《Plant Diversity》 2025年第3期382-393,共12页
The sugarcane subtribe Saccharinae(Andropogoneae,Poaceae)was established in 1846,but its delimitation has long been debated.Moreover,the relationships among the genera of Saccharinae remain unclear,and there is no con... The sugarcane subtribe Saccharinae(Andropogoneae,Poaceae)was established in 1846,but its delimitation has long been debated.Moreover,the relationships among the genera of Saccharinae remain unclear,and there is no consensus on whether Pseudosorghum,a small genus in tropical Asia with only two species,should be included.Here,we performed phylogenomic analyses using whole plastomes(69 of them newly sequenced)from 132 individuals,representing 65 species in 19 related genera.We also built trees with nuclear ribosomal DNA sequences.Our results justify the inclusion of Pseudosorghum,likely also the Eulalia Clade III,in Saccharinae.Furthermore,both morphological and molecular analyses support merging the two Pseudosorghum species.The backbone relationships of the Saccharinae phylogeny were highly supported with four polyphyletic clades of Miscanthus and the inclusion of Narenga and Tripidium rufipilum in Saccharum.Pseudosorghum is moderately supported as sister to the Miscanthus Clade I,while the remaining Tripidium species could be excluded from the subtribe.Saccharinae is estimated to have originated~3.73 million years ago in East Asia,followed by intercontinental dispersals.Our study provides a comprehensive phylogenetic framework for future taxonomic revisions of this economically important subtribe. 展开更多
关键词 PHYLOGENOMICS Saccharinae Pseudosorghum PLASTOME NRDNA Biogeography
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Microstructural evolution and its influence on the wear resistance of a laser directed energy deposited Ni-based single crystal superalloy
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作者 chenyu Ren kai chen +3 位作者 Jingjing Liang RLakshmi Narayan Upadrasta Ramamurty Jinguo Li 《Journal of Materials Science & Technology》 2025年第2期127-138,共12页
The wear behavior of Ni-based single crystal(NBSC)superalloy SRR99 fabricated by laser-directed energy deposition(LDED)is investigated and compared with that of its cast counterpart.While γ'precipitate size in th... The wear behavior of Ni-based single crystal(NBSC)superalloy SRR99 fabricated by laser-directed energy deposition(LDED)is investigated and compared with that of its cast counterpart.While γ'precipitate size in the latter is>400 nm,that in the former is an order of magnitude lower.Dry sliding wear tests reveal that the wear rate and coefficient of friction of the LDED alloy are 75% and 20%lower than that of its cast counterpart,respectively.Detailed transmission electron microscopy investigation of the wear-tested cast alloy indicates that there is orientation change and formation of nanoscale grains only at the top layer of the worn surface,whereas regions below undergo moderate plastic deformation via dislocation slip.In contrast,the sub-surface of the worn LDED alloy has a graded microstructure,with a composite of NiO/γ-Ni on the top,γ'free nano-grains in the middle,and a highly deformed nanoscale layer at the bottom.The improved wear behavior of the LDED alloy is attributed to its higher dislocation density,finerγ'precipitates,and the formation of this graded microstructure.Finally,a detailed description of mechanisms that lead to the formation of this unique graded microstructure is provided. 展开更多
关键词 In-situ formed gradient nanostructure Enhanced wear resistance Laser-directed energy deposition additive manufacturing Ni-based single crystal superalloys Plastic deformation
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Enhancing CO_(2) reduction efficiency with axial oxygen coordinated Ni-N_(4) active sites on hierarchical pore N-doped carbon
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作者 Xiaoxu Duan Junli Xu +5 位作者 Jiwei Li Congcong Du kai chen Teng Xu Yifei Sun Haifeng Xiong 《Chinese Chemical Letters》 2025年第7期212-216,共5页
The electrochemical reduction of carbon dioxide(CO_(2)RR)is a promising strategy for achieving carbon neutralization.The Ni-N_(4) site is well known as the active site in metal single atoms on N-doped carbon catalysts... The electrochemical reduction of carbon dioxide(CO_(2)RR)is a promising strategy for achieving carbon neutralization.The Ni-N_(4) site is well known as the active site in metal single atoms on N-doped carbon catalysts,while its symmetric charge distribution nature is not favorable for electron transfer and then hindering the efficient CO_(2)RR.Herein,we constructed a Ni SA/CNs single-atom catalyst.Notably,it features unique Ni-N_(4)-O active sites,featuring one axial O atom and four planar N atoms,constituting a broken symmetrical electronic structure of Ni-N_(4) sites.Furthermore,hierarchical pore structures were obtained with the assistance of NaNO_(3) pore-forming agent during thermal treatment process,which promote electronic and mass transfer.And the resulting high specific surface area can host more Ni-N_(4)-O active sites.These specialized active sites promote the key intermediate(∗CO)adsorption/desorption and suppresses hydrogen evolution.Consequently,the Ni SA/CNs catalyst exhibits a high turnover frequency(TOF)value,reaching 34,081 h^(-1) at-0.98 V vs.RHE.Additionally,it achieves an excellent CO Faradaic efficiency,exceeding 90%,over a wide potential range from-0.4 V to-1.0 V vs.RHE.This work not only offers a new method for the rational synthesize single-atom catalysts with unique Ni-N_(4)-O active sites,but also provides in-depth insight into the origin of catalytic activity of porous carbon-base catalysts. 展开更多
关键词 Nickel single-atom catalyst Ni-n_(4)-O active site CO_(2)electroreduction Hierarchical pore structure N-doped carbon
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Splenic histiocytic sarcoma:Disease progression from the perspective of pathophysiology
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作者 Meng-Ting Yao Tao Wang +3 位作者 Hao Luo Meng-Yuan Yao kai chen Yong-Qiang Zhu 《World Journal of Clinical Cases》 2025年第28期91-97,共7页
Splenic histiocytic sarcoma(SHS)is a rare,aggressive hematological malignancy with unclear progression and management.Our case illustrates the progression and pathophysiological processes of SHS and provides key data ... Splenic histiocytic sarcoma(SHS)is a rare,aggressive hematological malignancy with unclear progression and management.Our case illustrates the progression and pathophysiological processes of SHS and provides key data for the diagnosis,treatment and management of SHS.A 60-year-old female with incidentally detected splenic mass(6.0 cm×5.7 cm)underwent splenectomy,confirmed as SHS in 2020.Post-op imatinib therapy was given.In 2022,hepatic metastases(2.4 cm×2.9 cm)with pancytopenia led to supportive care.Lesions enlarged to 4.3 cm×2.7 cm,leading to multi-organ failure and death at 33 months.The case was categorized into three distinct stages based on the pathophysiology of SHS:Early-stage splenic tumor growth,mid-stage liver metastasis with hematological abnormalities,and late-stage tumor infiltration leading to multiorgan failure.For SHS,this case highlights the pivotal role of early intervention and the value of personalized treatment strategies. 展开更多
关键词 Splenic histiocytic sarcoma Hemophagocytic syndrome PATHOPHYSIOLOGY Disease progression THERAPY
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Antioxidant Glycopolypeptide Micelles for Targeted Delivery of Silibinin to Hepatocellular Carcinoma Cells
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作者 kai chen Ping Wei Jing-Hua chen 《Chinese Journal of Polymer Science》 2025年第11期2051-2060,I0011,共11页
Silibinin,a natural flavanone extracted from the milk thistle plant(Silybum marianum),has been shown to have various therapeutic applications,including liver protection,antioxidant,anticancer,anti-inflammatory,and man... Silibinin,a natural flavanone extracted from the milk thistle plant(Silybum marianum),has been shown to have various therapeutic applications,including liver protection,antioxidant,anticancer,anti-inflammatory,and many other effects.However,silibinin exhibits poor oral absorbance and low bioavailability owing to its limited water solubility,which limits its therapeutic efficiency and further clinical translation.To address these issues,we propose an antioxidant glycopolypeptide micelle strategy to target the delivery of silibinin to enhance its solubility,bioavailability,and antioxidant activity.This versatile micelle self-assembled from a glycopolypeptide,N-acetylgalactosamine-grafted poly(glutamic acid)-block-poly(tyrosine).N-acetylgalactosamine(Gal NAc)is incorporated to enable liver targeting by selectively binding to the asialoglycoprotein receptor,which is overexpressed on hepatocellular carcinoma cells.The antioxidant polypeptide polytyrosine,as well as encapsulated silibinin,exhibits a synergistic reactive oxygen species(ROS)scavenging effect.The obtained results confirmed that silibinin can be effectively encapsulated into the glycopolypeptide micelles through self-assembly,achieving a loading efficiency and loading content of 96.6%and 42.9%,respectively.The silibinin-loaded glycopolypeptide micelles exhibited enhanced cellular uptake and a synergistic ROS scavenging effect in hepatocellular carcinoma cells.Overall,these antioxidant glycopolypeptide micelles hold promise as safe and efficient drug delivery systems for targeting hepatocellular carcinoma cells,potentially providing an effective strategy to enhance the bioavailability and antioxidant activity of silibinin. 展开更多
关键词 SILIBININ Glycopolypeptide SELF-ASSEMBLY Antioxidant activity Liver-targeted
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A Strongly Coupled Cluster Heterostructure with Pt-N-Mo Bonding for Durable and Efficient H_(2)Evolution in Anion-Exchange Membrane Water Electrolyzers
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作者 Wenbo Zhou Yichao Huang +12 位作者 Hanqing Cai Tao Wang Haitao Li Chao Zhang Lianming Zhao Lulu chen Meihong Liao Zhiqing Tang kai chen Jing Gu Wenpei Gao Zhuangjun Fan Zhenhai Wen 《Nano-Micro Letters》 2025年第12期1-17,共17页
Creating strongly coupled heterostructures with favorable catalytic activities is crucial for promoting the performance of catalytic reactions,especially those involve multiple intermediates.Herein,we fabricated a str... Creating strongly coupled heterostructures with favorable catalytic activities is crucial for promoting the performance of catalytic reactions,especially those involve multiple intermediates.Herein,we fabricated a strongly coupled platinum/molybdenum nitrides nanocluster heterostructure on nitrogen-doped reduced graphene oxide(Pt/Mo_(2)N-NrGO)for alkaline hydrogen evolution reaction.The well-defined Pt-containing Anderson-type polyoxometalates promote strong interfacial Pt-N-Mo bonding in Pt/Mo_(2)N-NrGO,which exhibits a remarkably low overpotential,high mass activity,and exceptional long-term durability(>500 h at 1500 mA cm^(-2))in an anion-exchange membrane water electrolyzer(AEMWE).Operando Raman spectroscopy and density functional theory reveal that pronounced electronic coupling at the Pt/Mo_(2)N cluster interface facilitates the catalytic decomposition of H_(2)O through synergistic stabilization of intermediates(Pt-H^(*)and Mo-OH^(*)),thereby enhancing the kinetics of the rate-determining Volmer step.Techno-economic analysis indicates a levelized hydrogen production cost of$2.02 kg^(-1),meeting the US DOE targets.Our strategy presents a viable pathway to designing next-generation catalysts for industrial AEMWE for green hydrogen production. 展开更多
关键词 HETEROSTRUCTURES POLYOXOMETALATES ELECTROCATALYSIS Hydrogen evolution reaction Anion-exchange membrane water electrolyzers
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