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Estimation of cancer cell migration in biomimetic random/oriented collagen fiber microenvironments
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作者 姚静如 李国强 +8 位作者 姚喜耀 周连杰 叶志凯 刘艳平 郑栋天 唐婷 宋克纳 陈果 刘雳宇 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第5期749-756,共8页
Increasing data indicate that cancer cell migration is regulated by extracellular matrixes and their surrounding biochemical microenvironment,playing a crucial role in pathological processes such as tumor invasion and... Increasing data indicate that cancer cell migration is regulated by extracellular matrixes and their surrounding biochemical microenvironment,playing a crucial role in pathological processes such as tumor invasion and metastasis.However,conventional two-dimensional cell culture and animal models have limitations in studying the influence of tumor microenvironment on cancer cell migration.Fortunately,the further development of microfluidic technology has provided solutions for the study of such questions.We utilize microfluidic chip to build a random collagen fiber microenvironment(RFM)model and an oriented collagen fiber microenvironment(OFM)model that resemble early stage and late stage breast cancer microenvironments,respectively.By combining cell culture,biochemical concentration gradient construction,and microscopic imaging techniques,we investigate the impact of different collagen fiber biochemical microenvironments on the migration of breast cancer MDA-MB-231-RFP cells.The results show that MDA-MB-231-RFP cells migrate further in the OFM model compared to the RFM model,with significant differences observed.Furthermore,we establish concentration gradients of the anticancer drug paclitaxel in both the RFM and OFM models and find that paclitaxel significantly inhibits the migration of MDA-MB-231-RFP cells in the RFM model,with stronger inhibition on the high concentration side compared to the low concentration side.However,the inhibitory effect of paclitaxel on the migration of MDA-MB-231-RFP cells in the OFM model is weak.These findings suggest that the oriented collagen fiber microenvironment resembling the late-stage tumor microenvironment is more favorable for cancer cell migration and that the effectiveness of anticancer drugs is diminished.The RFM and OFM models constructed in this study not only provide a platform for studying the mechanism of cancer development,but also serve as a tool for the initial measurement of drug screening. 展开更多
关键词 microfluidic chip random collagen fiber microenvironment(RFM) oriented collagen fiber microenvironment(OFM) cancer cell migration
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漂浮型Bi_(2)WO_(6)/C_(3)N_(4)/碳布S型异质结光催化材料用于高效净化水体环境
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作者 蔡铭洁 刘艳萍 +2 位作者 董珂欣 陈晓波 李世杰 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2023年第9期239-251,共13页
近年来,水污染成为人类生存面临的巨大危机,如何治理水污染,特别是如何有效去除水体中的抗生素和重金属存在着很多挑战.采用先进、绿色且高效的光催化技术可有效去除水污染,因而受到科研工作者的广泛关注,但粉末状光催化剂易团聚、难分... 近年来,水污染成为人类生存面临的巨大危机,如何治理水污染,特别是如何有效去除水体中的抗生素和重金属存在着很多挑战.采用先进、绿色且高效的光催化技术可有效去除水污染,因而受到科研工作者的广泛关注,但粉末状光催化剂易团聚、难分离回收等问题限制了其工业应用.近年来,人们发现将粉末状光催化剂固定在柔性大表面积且电荷传导性能良好的碳布上可以有效克服上述缺点.g-C_(3)N_(4)具有高光还原活性、高稳定性和低成本的优点,因而在环境净化领域具有突出的应用潜力.但单一组分的C_(3)N_(4)/碳布仍存在氧化能力弱、光生载流子分离效率低等问题.将其与高光催化氧化活性且能带位置匹配的Bi_(2)WO_(6)共同构筑具有强内建电场和保留最大氧化还原能力的S型异质结,是一种有效策略,有望开发出高效、可回收的可见光光催化体系.本文以柔性、大的碳布为基底,通过热聚合-溶剂热法将C_3N4和富含氧空位的Bi_(2)WO_(6)原位生长在碳纤维上,制备出了富含氧空位的S型Bi_(2)WO_(6)C_(3)N_(4)/CF布状光催化剂,并用于可见光照射下高效光催化降解抗生素和还原Cr(VI).宏观图像、X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)和傅里叶红外光谱(FTIR)等结果表明,富含氧空位的Bi_(2)WO_(6)和C_(3)N_(4)纳米片均匀地生长在碳纤维上形成了2D/2D/1D分级易回收的布状结构.X射线光电子能谱(XPS)结果表明了Bi_(2)WO_(6)上氧空位、低价氧化态Bi^((3-x)+)和W^((5-x)+)的生成.与C_(3)N_(4)/CF(Bi_(2)WO_(6)CF)相比,Bi_(2)WO_(6)C_(3)N_(4)/CF在可见光照射下的光催化降解盐酸四环素和还原六价铬的效率分别提高了0.5(1.1)倍和30.2(19.8)倍.系统实验证明Bi_(2)WO_(6)C_(3)N_(4)/CF布状光催化剂较好的光催化性能归因于三个方面:(1)碳纤维编织而成的分级Bi_(2)WO_(6)C_(3)N_(4)/CF布结构可以暴露丰富的活性位点、促进污染物的富集以及加强界面电荷转移和空间分离;(2)缺陷工程协同S型光生载流子分离路径促进了电子和空穴的高效分离;(3)柔性可漂浮的布状结构赋予了其良好的易回收性和可循环利用性.此外,该布状光催化剂具有较好的环境普适性和毒性缓释作用,可以在不同影响因素下保持良好的光催化活性且降解中间产物毒性减弱.XPS结果中电子结合能的变化和功函数分析进一步确认了其S型光生载流子分离路径,并通过自由基捕获实验和电子自旋共振波谱仪系统研究了光催化反应机理:Bi_(2)WO_(6)C_(3)N_(4)/CF布状光催化剂通过S型光生载流子分离路径促进了超氧自由基和羟基自由基的生成,在降解盐酸四环素的过程中空穴和超氧自由基为主要活性物种,而在还原六价铬过程中电子和超氧自由基为主要活性基团.综上,本文采用缺陷工程结合碳布基底的S型异质结构筑策略,开发出高性能、易回收、稳定的漂浮型光催化体系,为高效净化水体环境提供了新思路. 展开更多
关键词 Bi_(2)WO_(6)/C_(3)N_(4)/碳布 氧空位 S型异质结 可漂浮光催化剂 可回收利用 内部电场
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Orderly hysteresis in field-driven robot swarm active matter
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作者 刘艳萍 王高 +5 位作者 王培龙 袁大明 侯帅旭 金阳凯 王璟 刘雳宇 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第6期673-681,共9页
Boundary effect and time-reversal symmetry are hot topics in active matter. We present a biology-inspired robotenvironment-interaction active matter system with the field-drive motion and the rules of resource search,... Boundary effect and time-reversal symmetry are hot topics in active matter. We present a biology-inspired robotenvironment-interaction active matter system with the field-drive motion and the rules of resource search, resource consumption, and resource recovery. In an environmental compression–expansion cycle, the swarm emerges a series of boundary-dependent phase transitions, and the whole evolution process is time-reversal symmetry-breaking;we call this phenomenon “orderly hysteresis”. We present the influence of the environmental recovery rate on the dynamic collective behavior of the swarm. 展开更多
关键词 time-reversal symmetry-breaking phase transitions robot swarm active matter
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Study on the Suitable Water-Saving Irrigation Technology for Mining Areas in the Northwestern Arid Desert Regions in China
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作者 yanping liu Hao Rong +1 位作者 Dan Shan Zhanqi Liang 《Journal of Geoscience and Environment Protection》 2020年第10期127-133,共7页
<div style="text-align:justify;"> Water is the key factor to ensure plant survival in the process of ecological restoration in the coal base of China northwest deserts. On the premise of meeting the mi... <div style="text-align:justify;"> Water is the key factor to ensure plant survival in the process of ecological restoration in the coal base of China northwest deserts. On the premise of meeting the mine production and living water demands, we should take measures such as dirt wastewater treatment and water-saving irrigation to increase income and reduce expenditure and allocate limited water re-sources rationally, to provide mining area ecological restoration maximum usable water resources. The mining dump has large slope and thin soil layer and it is easy to produce surface runoff. So it is particularly important to study the irrigation technology needed to satisfy vegetation restoration, on the premise of guaranteeing not to produce surface runoff and the slope stability. In this paper, through field plot test, the suitable irrigation method for mine slope, slope surface soil moisture migration characteristics and slope stability analysis were studied. Results show that three slope ir-rigation technologies have their own advantages and disadvantages. On the whole, the effect of drip irrigation is the best, micro spray irrigation is the second, infiltrating irrigation is not ideal. The permeability of mine soil slope is very strong, the infiltration rate of the slope direction is the high-est, inverse slope infiltration rate is lowest. In the process of irrigation, with the increase of soil moisture content, slope safety factor is the decreased obviously, the whole slope surface soil moisture content is 14% for the slope stability safety threshold. </div> 展开更多
关键词 Mining Areas Vegetation Restoration Side Slope Water-Saving Irrigation STABILITY
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右旋美托咪啶对中老年肺癌根治术患者术后认知功能的影响 被引量:3
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作者 刘艳萍 于婵娟 刘亚华 《临床检验杂志(电子版)》 2017年第2期179-180,共2页
目的观察右旋美托咪啶对中老年肺癌根治术患者术后认知功能的影响。方法 80例在全身麻醉双腔支气管插管下择期行肺癌根治术的患者随机分为对照组(C组)和右旋美托咪啶组(D组),C组患者采用丙泊酚+舒芬太尼+顺式阿曲库铵的常规诱导方式,诱... 目的观察右旋美托咪啶对中老年肺癌根治术患者术后认知功能的影响。方法 80例在全身麻醉双腔支气管插管下择期行肺癌根治术的患者随机分为对照组(C组)和右旋美托咪啶组(D组),C组患者采用丙泊酚+舒芬太尼+顺式阿曲库铵的常规诱导方式,诱导完全后,插入双腔支气管导管,D组采用1μg/mL右旋美托咪定术前30 min开始持续泵注,麻醉诱导与气管插管方式与对照组相同。观察两组患者7项认知功能于手术前、术后3 d和7 d的测评情况。7项测试项目中至少2项,单项测试值低于基础值20%以上者,确认为认知功能损害。结果 80例病人术后3 d和7 d认知功能的发生率分别为63.2%和41.3%。年龄与术后认知功能测试项目中的视觉再生(r=-0.47)和钉板试验(r=-0.47)有相关关系。结论中老年患者行创伤较大的手术,特别是高龄病人早期存在认知功能紊乱,应当引起临床医师的足够重视。右美托咪定对中老年患者术后早期的认知功能紊乱有一定的预防作用。 展开更多
关键词 右旋美托咪啶 认知功能障碍 肺癌根治术
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新型氮氧化钽/氧空位钨酸铋S型异质结纤维用于高效光催化降解抗生素和还原六价铬:产物毒性分析和光催化机理研究 被引量:8
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作者 李世杰 蔡铭洁 +3 位作者 刘艳萍 王春春 吕康乐 陈晓波 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2022年第10期2652-2664,共13页
近年来,环境污染问题严重地威胁着人类的生存和健康.半导体光催化是一种绿色环保的治理环境污染技术,该技术实现大规模应用的关键在于构建高效的光催化剂.TaON因优异的光电性质、稳定的物理化学性质及适合的能带结构等优势,被广泛应用... 近年来,环境污染问题严重地威胁着人类的生存和健康.半导体光催化是一种绿色环保的治理环境污染技术,该技术实现大规模应用的关键在于构建高效的光催化剂.TaON因优异的光电性质、稳定的物理化学性质及适合的能带结构等优势,被广泛应用于光催化水裂解和有害污染物降解等领域.但光生载流子快速复合和比表面积小等问题严重制约了其大规模应用.近年来,人们发现构建新型S型异质结能有效促进光生电子和空穴分离,同时充分保存具有强氧化还原能力的电子和空穴,进而有效提升材料的光催化性能.因此,通过构建新型TaON S型异质结光催化材料有f望开发出高效的可见光光催化体系.本文采用静电纺丝-煅烧-氮化工艺制备出由纳米颗粒组成的多孔TaON纳米纤维,然后采用溶剂热法制得一系列富含氧空位的TaON/Bi_(2)WO_(6) S型异质结纤维,并用于可见光照射下光催化降解抗生素和还原Cr^(6+).实验发现,富含氧空位的Bi_(2)WO_(6)二维纳米片均匀生长在TaON纳米纤维上形成了良好的1D/2D核壳结构,此异质结界面结构有利于界面间电荷的分离和传输.当TaON/Bi_(2)WO_(6)质量比为20 wt%时,在可见光下分别照射50,60和50 min,20 mg复合纤维可降解93.2%的四环素溶液(20 mg/L,100 mL,pH=5.2),83.7%的左氧氟沙星溶液(20 mg/L,100 mL,pH 6.7)以及还原95.6%的Cr^(6+)溶液(10 mg/L,100 mL,pH=2.5),其对三种污染物的去除速率分别是纯Bi_(2)WO_(6)的3.8,2和2.9倍,且远高于纯TaON纤维.此外,该复合纤维具有良好的矿化能力及循环稳定性,在实际废水中依然表现出较好的催化降解活性.表征结果表明,复合纤维光催化活性增强是由于TaON与Bi_(2)WO_(6)之间形成了S型的异质结,并富含氧空位;在内电场,能带弯曲和库仑力的协同作用下,实现了强氧化还原能力的电子和空穴的高效分离和保存,有效提升了体系的光催化性能.综上,本文采用缺陷工程结合异质构筑策略有效地提升了体系的光催化活性,为开发高效的光催化体系提供一定的参考. 展开更多
关键词 TaON/Bi_(2)WO_(6) S型异质结 静电纺丝 氧空位 抗生素降解 六价铬还原
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Wheat straw pretreatment with KOH for enhancing biomethane production and fertilizer value in anaerobic digestion 被引量:11
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作者 Muhammad Jaffar Yunzhi Pang +5 位作者 Hairong Yuan Dexun Zou yanping liu Baoning Zhu Rashid Mustafa Korai Xiujin Li 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2016年第3期404-409,共6页
Wheat straw biodegradability during anaerobic digestion was improved by treatment with potassium hydroxide(KOH)to decrease digestion time and enhance biomethane production and fertility value.KOH concentrations of1%(K... Wheat straw biodegradability during anaerobic digestion was improved by treatment with potassium hydroxide(KOH)to decrease digestion time and enhance biomethane production and fertility value.KOH concentrations of1%(K1),3%(K2),6%(K3)and 9%(K4)were tested for wheat straw pretreatment at ambient temperature with a C:N ratio of 25:1.86% of total solids(TS),89% of volatile solids(VS)and 22% of lignocellulose,cellulose and hemicellulose(LCH)(22%)were decomposed effectively with the wheat straw pretreated by 6% KOH.Enhanced biogas production and cumulative biomethane yield of 258 ml·(g VS)^(-1)were obtained increased by 45% and 41%respectively,compared with untreated wheat straw.Pretreated wheat straw digestion also yielded a digestate with higher fertilizer values potassium(138%),calcium(22%)and magnesium(16%).These results show that TS,VS and LCH can be effectively removed from wheat straw pretreated with KOH,improving biodegradability biomethane production and fertilizer value. 展开更多
关键词 厌氧消化过程 秸秆预处理 小麦秸秆 KOH 高沼气 生产 价值 肥料
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Recent Progress in the Fabrication, Properties, and Devices of Heterostructures Based on 2D Materials 被引量:13
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作者 yanping liu Siyu Zhang +2 位作者 Jun He Zhiming M.Wang Zongwen liu 《Nano-Micro Letters》 SCIE EI CAS CSCD 2019年第1期217-240,共24页
With a large number of researches being conducted on two?dimen?sional(2D) materials, their unique properties in optics, electrics, mechanics, and magnetics have attracted increasing attention. Accordingly, the idea of... With a large number of researches being conducted on two?dimen?sional(2D) materials, their unique properties in optics, electrics, mechanics, and magnetics have attracted increasing attention. Accordingly, the idea of combining distinct functional 2D materials into heterostructures naturally emerged that pro?vides unprecedented platforms for exploring new physics that are not accessible in a single 2D material or 3D heterostructures. Along with the rapid development of controllable, scalable, and programmed synthesis techniques of high?quality 2D heterostructures, various heterostructure devices with extraordinary performance have been designed and fabricated, including tunneling transistors, photodetectors, and spintronic devices. In this review, we present a summary of the latest progresses in fabrications, properties, and applications of di erent types of 2D heterostruc?tures, followed by the discussions on present challenges and perspectives of further investigations. 展开更多
关键词 Two-dimensional(2D) materials 2D heterostructures Charge and magnetotransport Electronic and optoelectronic devices
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用于食品中玉米赤霉烯酮高灵敏、快速检测的倏逝波免疫传感技术
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作者 刘艳萍 方顺燕 +5 位作者 徐文娟 刘佳瑶 宋丹 王宏亮 韩向峙 龙峰 《环境化学》 CAS CSCD 北大核心 2021年第5期1583-1591,共9页
玉米赤霉烯酮(zearalenone,ZEN)是一种由镰刀菌属产生的次级代谢产物,利用课题组自主研发的倏逝波光纤免疫传感器,以玉米赤霉烯酮包被抗原修饰的光纤探头作为生物识别元件,基于间接竞争免疫分析原理,建立了ZEN的高灵敏、快速定量检测方... 玉米赤霉烯酮(zearalenone,ZEN)是一种由镰刀菌属产生的次级代谢产物,利用课题组自主研发的倏逝波光纤免疫传感器,以玉米赤霉烯酮包被抗原修饰的光纤探头作为生物识别元件,基于间接竞争免疫分析原理,建立了ZEN的高灵敏、快速定量检测方法。在最佳检测条件下,ZEN的检测限为0.35μg·L^(−1),线性区间为0.75—7.48μg·L^(−1),单个检测周期只需8 min。包被抗原修饰的光纤探头可重复使用100次以上而没有明显的性能损失,可以保证检测结果的准确性并降低成本。对小麦、玉米、猪饲料进行了不同浓度的加标回收测试,结果显示加标回收率在80.86%—113.92%范围内,相对标准偏差小于7.90%,表明该传感器具有很好的稳定性和精确度,可以用于食品中ZEN的快速检测,为食品安全评价提供有力分析工具。 展开更多
关键词 玉米赤霉烯酮 倏逝波 传感器 检测
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Spintronics in Two-Dimensional Materials 被引量:1
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作者 yanping liu Cheng Zeng +3 位作者 Jiahong Zhong Junnan Ding Zhiming MWang Zongwen liu 《Nano-Micro Letters》 SCIE EI CAS CSCD 2020年第7期192-217,共27页
Spintronics,exploiting the spin degree of electrons as the information vector,is an attractive field for implementing the beyond Complemetary metal-oxide-semiconductor(CMOS)devices.Recently,two-dimensional(2D)material... Spintronics,exploiting the spin degree of electrons as the information vector,is an attractive field for implementing the beyond Complemetary metal-oxide-semiconductor(CMOS)devices.Recently,two-dimensional(2D)materials have been drawing tremendous attention in spintronics owing to their distinctive spin-dependent properties,such as the ultralong spin relaxation time of graphene and the spin-valley locking of transition metal dichalcogenides.Moreover,the related heterostructures provide an unprecedented probability of combining the di erent characteristics via proximity e ect,which could remedy the limitation of individual 2D materials.Hence,the proximity engineering has been growing extremely fast and has made significant achievements in the spin injection and manipulation.Nevertheless,there are still challenges toward practical application;for example,the mechanism of spin relaxation in 2D materials is unclear,and the high-effciency spin gating is not yet achieved.In this review,we focus on 2D materials and related heterostructures to systematically summarize the progress of the spin injection,transport,manipulation,and application for information storage and processing.We also highlight the current challenges and future perspectives on the studies of spintronic devices based on 2D materials. 展开更多
关键词 SPINTRONICS 2D MATERIALS TMDCs HETEROSTRUCTURE PROXIMITY EFFECT
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FLIM as a Promising Tool for Cancer Diagnosis and Treatment Monitoring 被引量:1
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作者 Yuzhen Ouyang yanping liu +2 位作者 Zhiming MWang Zongwen liu Minghua Wu 《Nano-Micro Letters》 SCIE EI CAS CSCD 2021年第9期48-74,共27页
Fluorescence lifetime imaging microscopy(FLIM)has been rapidly developed over the past 30 years and widely applied in biomedical engineering.Recent progress in fluorophore-dyed probe design has widened the application... Fluorescence lifetime imaging microscopy(FLIM)has been rapidly developed over the past 30 years and widely applied in biomedical engineering.Recent progress in fluorophore-dyed probe design has widened the application prospects of fluorescence.Because fluorescence lifetime is sensitive to microenvironments and molecule alterations,FLIM is promising for the detection of pathological conditions.Current cancer-related FLIM applications can be divided into three main categories:(i)FLIM with autofluorescence molecules in or out of a cell,especially with reduced form of nicotinamide adenine dinucleotide,and flavin adenine dinucleotide for cellular metabolism research;(ii)FLIM with Förster resonance energy transfer for monitoring protein interactions;and(iii)FLIM with fluorophore-dyed probes for specific aberration detection.Advancements in nanomaterial production and efficient calculation systems,as well as novel cancer biomarker discoveries,have promoted FLIM optimization,offering more opportunities for medical research and applications to cancer diagnosis and treatment monitoring.This review summarizes cutting-edge researches from 2015 to 2020 on cancer-related FLIM applications and the potential of FLIM for future cancer diagnosis methods and anti-cancer therapy development.We also highlight current challenges and provide perspectives for further investigation. 展开更多
关键词 Fluorescence lifetime imaging microscopy Förster resonance energy transfer Reduced form of nicotinamide adenine dinucleotide Biosensors CANCER
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Quantitative heterogeneity and subgroup classification based on motility of breast cancer cells
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作者 熊玲 刘艳平 +9 位作者 刘如川 袁伟 王高 何益 帅建伟 焦阳 张溪祥 韩伟静 屈军乐 刘雳宇 《Chinese Physics B》 SCIE EI CAS CSCD 2019年第10期590-596,共7页
Cancer cell motility and its heterogeneity play an important role in metastasis, which is responsible for death of 90% of cancer patients. Here, in combination with a microfluidic technique, single-cell tracking, and ... Cancer cell motility and its heterogeneity play an important role in metastasis, which is responsible for death of 90% of cancer patients. Here, in combination with a microfluidic technique, single-cell tracking, and systematic motility analysis,we present a rapid and quantitative approach to judge the motility heterogeneity of breast cancer cells MDA-MB-231 and MCF-7 in a well-defined three-dimensional(3D) microenvironment with controllable conditions. Following this approach,identification of highly mobile active cells in a medium with epithelial growth factor will provide a practical tool for cell invasion and metastasis investigation of multiple cancer cell types, including primary cells. Further, this approach could potentially become a speedy(~ hours) and efficient tool for basic and clinical diagnosis. 展开更多
关键词 cancer METASTASIS MOTILITY HETEROGENEITY three-dimensional MICROENVIRONMENT INVASION potential
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Nonlinear dynamics of cell migration in anisotropic microenvironment
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作者 刘艳平 何达 +8 位作者 焦阳 李国强 郑钰 樊琪慧 王高 姚静如 陈果 娄四龙 刘雳宇 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第9期166-177,共12页
Cell migration in anisotropic microenvironment plays an important role in the development of normal tissues and organs as well as neoplasm progression,e.g.,osteogenic differentiation of embryonic stem cells was facili... Cell migration in anisotropic microenvironment plays an important role in the development of normal tissues and organs as well as neoplasm progression,e.g.,osteogenic differentiation of embryonic stem cells was facilitated on stiffer substrates,indicating that the mechanical signals greatly affect both early and terminal differentiation of embryonic stem cells.However,the effect of anisotropy on cell migration dynamics,in particular,in terms of acceleration profiles which is important for recognizing dynamics modes of cell migration and analyzing the regulation mechanisms of microenvironment in mechanical signal transmission,has not been systematically investigated.In this work,we firstly rigorously investigate and quantify the differences between persistent random walk and anisotropic persistent random walk models based on the analysis of cell migration trajectories and velocity auto-covariance function,both qualitatively and quantitatively.Secondly,we introduce the concepts of positive and negative anisotropy based on the motility parameters to study the effect of anisotropy on acceleration profiles,especially the nonlinear decrease and non-monotonic behaviors.We particularly elaborate and discuss the mechanisms,and physical insights of non-monotonic behaviors in the case of positive anisotropy,focusing on the force exerted on migrating cells.Finally,we analyze two types of in vitro cell migration experiments and verify the universality of nonlinear decrease and the consistence of non-monotonic behaviors with numerical results.We conclude that the anisotropy of microenvironment is the cause of the non-monotonic and nonlinear dynamics,and the anisotropic persistent random walk can be as a suitable tool to analyze in vitro cell migration with different combinations of motility parameters.Our analysis provides new insights into the dynamics of cell migration in complex microenvironment,which also has implications in tissue engineering and cancer research. 展开更多
关键词 cell migration nonlinear behavior motility parameter acceleration profile anisotropic microenvironment
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A 3D biophysical model for cancer spheroid cell-enhanced invasion in collagen-oriented fiber microenvironment
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作者 海苗苗 刘艳平 +6 位作者 熊玲 李国强 王高 张鸿飞 帅建伟 陈果 刘雳宇 《Chinese Physics B》 SCIE EI CAS CSCD 2020年第9期581-588,共8页
The process of in situ tumors developing into malignant tumors and exhibiting invasive behavior is extremely complicated.From a biophysical point of view,it is a phase change process affected by many factors,including... The process of in situ tumors developing into malignant tumors and exhibiting invasive behavior is extremely complicated.From a biophysical point of view,it is a phase change process affected by many factors,including cell-to-cell,cell-to-chemical material,cell-to-environment interaction,etc.In this study,we constructed spheroids based on green fluorescence metastatic breast cancer cells MDA-MB-231 to simulate malignant tumors in vitro,while constructed a three-dimensional(3D)biochip to simulate a micro-environment for the growth and invasion of spheroids.In the experiment,the 3D spheroid was implanted into the chip,and the oriented collagen fibers controlled by collagen concentration and injection rate could guide the MDA-MB-231 cells in the spheroid to undergo directional invasion.The experiment showed that the oriented fibers greatly accelerated the invasion speed of MDA-MB-231 cells compared with the traditional uniform tumor micro-environment,namely obvious invasive branches appeared on the spheroids within 24 hours.In order to analyze this interesting phenomenon,we have developed a quantitative analyzing approach to explore strong angle correlation between the orientation of collagen fibers and invasive direction of cancer cell.The results showed that the oriented collagen fibers produced by the chip can greatly stimulate the invasion potential of cancer cells.This biochip is not only conducive to modeling cancer cell metastasis and studying cell invasion mechanisms,but also has the potential to build a quantitative evaluation platform that can be used in future chemical drug treatments. 展开更多
关键词 3D biochip SPHEROIDS MDA-MB-231 cells oriented collagen fibers cancer cell invasion
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Biophysical model for high-throughput tumor and epithelial cell co-culture in complex biochemical microenvironments
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作者 李国强 刘艳平 +5 位作者 姚静如 宋克纳 王高 周连杰 陈果 刘雳宇 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第2期154-163,共10页
The in vivo tumor microenvironment is a complex niche that includes heterogeneous physical structures,unique biochemical gradients and multiple cell interactions.Its high-fidelity in vitro reconstruction is of fundame... The in vivo tumor microenvironment is a complex niche that includes heterogeneous physical structures,unique biochemical gradients and multiple cell interactions.Its high-fidelity in vitro reconstruction is of fundamental importance to improve current understandings of cell behavior,efficacy predictions and drug safety.In this study,we have developed a high-throughput biochip with hundreds of composite extracellular matrix(ECM)microchambers to co-culture invasive breast cancer cells(MDA-MB-231-RFP)and normal breast epithelial cells(MCF-10 A-GFP).The composite ECM is composed of type I collagen and Matrigel which provides a heterogeneous microenvironment that is similar to that of in vivo cell growth.Additionally,the growth factors and drug gradients that involve human epidermal growth factor(EGF),discoidin domain receptor 1(DDR1)inhibitor 7 rh and matrix metalloproteinase inhibitor batimastat allow for the mimicking of the complex in vivo biochemical microenvironment to investigate their effect on the spatial-temporal dynamics of cell growth.Our results demonstrate that the MDA-MB-231-RFP cells and MCF-10 A-GFP cells exhibit different spatial proliferation behaviors under the combination of growth factors and drugs.Basing on the experimental data,we have also developed a cellular automata(CA)model that incorporated drug diffusion to describe the experimental phenomenon,as well as employed Shannon entropy(SE)to explore the effect of the drug diffusion coefficient on the spatial-temporal dynamics of cell growth.The results indicate that the uniform cell growth is related to the drug diffusion coefficient,which reveals that the pore size of the ECM plays a key role in the formation of complex biochemical gradients.Therefore,our integrated,biomimetic and high-throughput co-culture platforms,as well as the computational model can be used as an effective tool for investigating cancer pathogenesis and drug development. 展开更多
关键词 microfluidic HIGH-THROUGHPUT biochemical gradient cancer
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阅读过程中适应性眼动控制的出现:理论和数据(中文)
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作者 Erik D. Reichle yanping liu Patryk A. Laurent 《心理与行为研究》 CSSCI 2011年第1期45-52,共8页
Computational models of eye-movement control during reading provide precise quantitative descriptions of the perceptual, cognitive, and motoric processing that guide readers′ eyes, but are based on numerous equivocal... Computational models of eye-movement control during reading provide precise quantitative descriptions of the perceptual, cognitive, and motoric processing that guide readers′ eyes, but are based on numerous equivocal a priori theoretical assumptions. This article describes an alternative approach to understanding eye-movement control: Using reinforcement learning to examine how complex eye-movement behaviors emerge from the requirement to identify words rapidly in the context of known psychological and physiological constraints(e.g., limited visual acuity). An example simulation is reported, as are key results from an fMRI experiment that demonstrates that structures implicated in reinforcement learning support the learning of eye-movement behavior in humans. 展开更多
关键词 心理学 行为 研究 理论
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Factors Obstructing Rural Informationization Development of Pingshan County of Hebei Province
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作者 Shuhong CAI Haiyan CAI +1 位作者 Haiying DU yanping liu 《Asian Agricultural Research》 2014年第4期124-128,共5页
The purpose of rural informationization is to provide effective information for farmers,increase production efficiency and income level of farmers in agricultural production.In recent years,under the guidance of No.1 ... The purpose of rural informationization is to provide effective information for farmers,increase production efficiency and income level of farmers in agricultural production.In recent years,under the guidance of No.1 document of central government,China's rural informationization has obtained considerable development.However,due to influence of terrain,mountain areas are still backward in informationization development.Combining actual conditions of Pingshan County of Hebei Province,the authors visited local farmers and made detailed survey on basic conditions of farmers,and analyzed factors obstructing agricultural informationization development in mountain areas,to provide theoretical reference for promoting informationization development in mountain areas and increasing income of local farmers. 展开更多
关键词 Pingshan COUNTY RURAL informationization Obstructi
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Research on Urban Community Facilities Safety Governance—Based on the Overall Perspective
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作者 yanping liu Zhixiang Yuan Yong Wang 《World Journal of Engineering and Technology》 2017年第3期36-41,共6页
Community facilities accidents happen every year in many cities of China, which has been an important issue in academic circles. The purpose of this study is to suggest the direction of universal design for the preven... Community facilities accidents happen every year in many cities of China, which has been an important issue in academic circles. The purpose of this study is to suggest the direction of universal design for the prevention of community facilities accidents. In this paper, from the overall angle, the impact factors of the urban community service facilities safety were analyzed. Then, based on the integrated governance theory, from such aspects as engineering and non-engineering disaster reduction, the governance measures were explored. 展开更多
关键词 COMMUNITY Facilities INTEGRATED GOVERNANCE THEORY
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Photodynamic Therapy for Advanced Rectal Cancer:A Case Report
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作者 Lemei Chen yanping liu +1 位作者 Ping Xie Huizhen Fan 《Journal of Clinical and Nursing Research》 2020年第6期32-36,共5页
Objective:To investigate the potential value of PDT(photodynamic therapy)in the treatment of rectal cancer by reviewing the diagnosis and treatment process of a patient with advanced rectal cancer who lost the opportu... Objective:To investigate the potential value of PDT(photodynamic therapy)in the treatment of rectal cancer by reviewing the diagnosis and treatment process of a patient with advanced rectal cancer who lost the opportunity of surgery.Methods:Select the case data of a patient receiving photodynamic therapy in our hospital,and analyze the photodynamic mechanism safety and efficiency,and discuss the efficacy of photodynamic therapy.Results:After the patient received photodynamic therapy,re-examination of the endoscopy showed that the intestinal cavity was smoother than before,the bowel was difficult,and the symptoms of blood in the stool improved.Conclusion:Photodynamic therapy can be used as a radical or palliative treatment for clinical tumor treatment.Because of its advantages of minimally invasive,tissue-specific,repetitive and synergistic radiotherapy and chemotherapy,it plays an important role in early or middle-advanced colorectal cancer and is worthy of clinical promotion. 展开更多
关键词 Rectal cancer Photodynamic therapy Curative effect
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碳量子点/四(4-羧基苯基)卟啉/BiOBr S型异质结用于高效光催化降解抗生素 被引量:1
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作者 王春春 戎珂 +2 位作者 刘艳萍 杨方 李世杰 《Science China Materials》 SCIE EI CAS CSCD 2024年第2期562-572,共11页
太阳能光催化处理制药废水是缓解环境问题和能源危机的一种很有前途的方法.然而,提高其处理效率面临众多挑战,如光吸收效率低、光生载流子快速复合和光氧化还原电位低等.本文通过在BiOBr(BOB)微球上沉积碳量子点(CDs)和四(4-羧基苯基)卟... 太阳能光催化处理制药废水是缓解环境问题和能源危机的一种很有前途的方法.然而,提高其处理效率面临众多挑战,如光吸收效率低、光生载流子快速复合和光氧化还原电位低等.本文通过在BiOBr(BOB)微球上沉积碳量子点(CDs)和四(4-羧基苯基)卟啉(TCPP),巧妙地构建了TCPP/CDs/BOB有机/无机三元S型异质结,用于在可见光下有效降解水体中的盐酸四环素(TC).研究发现,由于两者之间的费米能级差异,在形成异质结时触发了电子从TCPP传递到BOB,从而在界面处构建内部电场(IEF).这极大推动了光诱导载流子的有效分离.此外,CDs作为电子收集器进一步提高了S型异质结的载流子分离能力,因此保留了在CDs中聚集更强还原能力的光电子和在BOB价带中更强氧化能力的空穴来参与光催化反应.在这些催化剂中,TCPP/CDs/BOB-2异质结催化剂在40 min内对TC的降解能力高达83.6%.TCPP/CDs/BOB-2的反应速率常数(k)分别约为BOB、CDs/BOB和TCPP/BOB的2.3、1.8和2.0倍.这项工作为探索用于水净化的有机/无机三元S型光催化剂提供了新的视角. 展开更多
关键词 carbon quantum dots organic/inorganic S-scheme heterojunction tetra(4-carboxyphenyl)porphyrin/BiOBr internal electric field PHOTOCATALYSIS
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