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文章速递New Dinosaur Tracks from the Lower Barremian of Portugal (Areia do Mastro Formation, Cape Espichel) 认领
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作者 Silvério D. Figueiredo Carlos Neto de Carvalho +1 位作者 Pedro P. Cunha Ismar de Sousa Carvalho 《地球科学和环境保护期刊(英文)》 2021年第1期84-96,共13页
We present a new tracksite with multiple dinosaur tracks from the lowermost Barremian (Lower Cretaceous) of the Cape Espichel (Sesimbra, Portugal). The tracks are localized on three beds on the top carbonate beds of t... We present a new tracksite with multiple dinosaur tracks from the lowermost Barremian (Lower Cretaceous) of the Cape Espichel (Sesimbra, Portugal). The tracks are localized on three beds on the top carbonate beds of the Areia do Mastro Formation. Those bioclastic, nodular limestones were deposited in a very shallow subtidal-intertidal, restricted lagoon environment. The track surfaces are very dinoturbated, with a substantial number of tracks. Several tracks assign to sauropods, ornithopods and theropods dinosaurs were recorded. Due to heavy bioturbation and the preservation conditions, it is not possible to define trackways;some preliminary work done on the tracks could disclose some behaviours of their producers. Several species of carnivore and herbivore dinosaurs crossed that large area at different times. Herbivores may have used the lagoon margin as passage between feeding spots, while carnivores frequented the area to hunt in groups or individually. 展开更多
关键词 Trampled Surface Dinosaurs Locomotion Behavior Lower Cretaceous Cape Espichel Portugal Iberia
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文章速递A Data-Driven Research of Sales and Purchases on JD.com Platform 认领
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作者 Xiangyu Huang 《智能信息管理(英文)》 2021年第1期31-49,共19页
Unlike consumers in the mall or supermarkets, online consumers are “intangible” and their purchasing behaviors are affected by multiple factors, including product pricing, promotion and discounts, quality of product... Unlike consumers in the mall or supermarkets, online consumers are “intangible” and their purchasing behaviors are affected by multiple factors, including product pricing, promotion and discounts, quality of products and brands, and the platforms where they search for the product. In this research, I study the relationship between product sales and consumer characteristics, the relationship between product sales and product qualities, demand curve analysis, and the search friction effect for different platforms. I utilized data from a randomized field experiment involving more than 400 thousand customers and 30 thousand products on JD.com, one of the world’s largest online retailing platforms. There are two focuses of the research: 1) how different consumer characteristics affect sales;2) how to set price and possible search friction for different channels. I find that JD plus membership, education level and age have no significant relationship with product sales, and higher user level leads to higher sales. Sales are highly skewed, with very high numbers of products sold making up only a small percentage of the total. Consumers living in more industrialized cities have more purchasing power. Women and singles lead to higher spending. Also, the better the product performs, the more it sells. Moderate pricing can increase product sales. Based on the research results of search volume in different channels, it is suggested that it is better to focus on app sales. By knowing the results, producers can adjust target consumers for different products and do target advertisements in order to maximize the sales. Also, an appropriate price for a product is also crucial to a seller. By the way, knowing the search friction of different channels can help producers to rearrange platform layout so that search friction can be reduced and more potential deals may be made. 展开更多
关键词 E-Tailing Data-Driven Research Sales Price-Discrimination Search-Friction Channels Consumer Behavior
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文章速递Study on Local Optical Flow Method Based on YOLOv3 in Human Behavior Recognition 认领
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作者 Hao Zheng Jianfang Liu Mengyi Liao 《电脑和通信(英文)》 2021年第1期10-18,共9页
In the process of human behavior recognition, the traditional dense optical flow method has too many pixels and too much overhead, which limits the running speed. This paper proposed a method combing YOLOv3 (You Only ... In the process of human behavior recognition, the traditional dense optical flow method has too many pixels and too much overhead, which limits the running speed. This paper proposed a method combing YOLOv3 (You Only Look Once v3) and local optical flow method. Based on the dense optical flow method, the optical flow modulus of the area where the human target is detected is calculated to reduce the amount of computation and save the cost in terms of time. And then, a threshold value is set to complete the human behavior identification. Through design algorithm, experimental verification and other steps, the walking, running and falling state of human body in real life indoor sports video was identified. Experimental results show that this algorithm is more advantageous for jogging behavior recognition. 展开更多
关键词 YOLOv3 Local Optical Flow Method Human Behavior Recognition
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文章速递预防医学专业学生对新型冠状病毒肺炎的知信行现状调查分析 认领
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作者 张洁 刘家瑄 +1 位作者 陈莹 刘刊 《现代医药卫生》 2021年第3期378-380,共3页
目的了解预防医学专业学生对新型冠状病毒肺炎(新冠肺炎)的知信行现状,为下一阶段高职院校在疫情的防控策略方面提供思路。方法采用自行设计问卷、利用网络在线调查,对贵州省某高职院校预防医学专业学生进行调查。结果被调查的285名学... 目的了解预防医学专业学生对新型冠状病毒肺炎(新冠肺炎)的知信行现状,为下一阶段高职院校在疫情的防控策略方面提供思路。方法采用自行设计问卷、利用网络在线调查,对贵州省某高职院校预防医学专业学生进行调查。结果被调查的285名学生对新冠肺炎的认知得分为(60.49±27.03)分。37.5%的学生表示在面对疫情期间有不同程度焦虑。在新冠肺炎行为方面表现较好。结论该校预防医学专业学生对新冠肺炎的认知率还有待提高,学校应结合学生的特点有针对性地进行宣传工作,转变健康传播模式,从而提高学生的认知水平,消除其焦虑情绪,使其成为真正的基层公共卫生"守门人"。 展开更多
关键词 新型冠状病毒肺炎 预防医学 知识 态度 行为
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文章速递医学生与非医学生预防接种知识、态度和行为的调查 认领
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作者 邬朋格 董琳曼 +2 位作者 慕莹莹 刘毅 孟亚 《现代医药卫生》 2021年第3期381-384,387,共5页
目的了解医学与非医学专业学生对常见传染病相关知识的知晓情况、预防接种态度和行为现状,对不同人群提出针对性的宣传防控建议,为高校大学生预防接种提供参考。方法采取分层整群随机抽样法抽取郑州市某民办高校医学专业1 085名、非医... 目的了解医学与非医学专业学生对常见传染病相关知识的知晓情况、预防接种态度和行为现状,对不同人群提出针对性的宣传防控建议,为高校大学生预防接种提供参考。方法采取分层整群随机抽样法抽取郑州市某民办高校医学专业1 085名、非医学专业515名在校学生进行问卷调查。共发放问卷2 000份,回收率为91.4%,剔除无效问卷剩余有效问卷1 600份,有效回收率为87.5%。结果学生对宫颈癌的知晓率极低,仅有32.5%(520/1 600)的学生知晓宫颈癌与人乳头瘤病毒(HPV)感染的关系。宫颈癌疫苗接种率仅为2.4%(39/1 600);对感染肺结核后临床症状知晓率较高,其中咳嗽这一症状高达76.1%(1 218/1 600),对卡介苗接种意愿高达84.1%(1 346/1 600);对乙型肝炎(乙肝)传播途径的知晓率为52.6%(842/1 600),乙肝疫苗的接种率为61.2%(979/1 600)。医学生与非医学生对宫颈癌、肺结核、乙肝相关知识的知晓率及相关疫苗接种率比较,差异均有统计学意义(P<0.05)。结论不同专业的大学生对预防接种认知、态度、行为存在差异,非医学专业学生对传染病相关知识欠缺,重视程度不够。 展开更多
关键词 医学生 非医学生 预防接种 知识 态度 行为 对比研究
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文章速递基于IAD框架的医疗制度与医患行为者关系研究 认领
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作者 陆方 王锦帆 《中国医院管理》 北大核心 2021年第2期62-64,共3页
医患关系作为复杂的社会关系,深深地嵌入到其所处的社会组织、关系、文化和制度系统中。政府部门和医疗机构制定和出台的各项医疗制度无疑对医患关系产生重要影响。利用制度分析与发展框架(IAD)解释医疗制度与医患行为者的关系,并从医... 医患关系作为复杂的社会关系,深深地嵌入到其所处的社会组织、关系、文化和制度系统中。政府部门和医疗机构制定和出台的各项医疗制度无疑对医患关系产生重要影响。利用制度分析与发展框架(IAD)解释医疗制度与医患行为者的关系,并从医疗制度的宏观层面和微观层面举例分析不同制度影响下医患双方互动的作用模式及产生的关系结果,识别医疗制度对行为者的影响路径,剖析医患关系紧张的深层次原因和形成机制,为医疗管理领域的理论研究和实践应用提供借鉴。 展开更多
关键词 医疗制度 行为 互动 医患关系 制度分析与发展框架
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Experimental Study on the Expansion Behavior of Full Aggregate Steel Slag Concrete 认领
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作者 Feng Yu Xuliang Wang +1 位作者 Yang Zhang Yuan Fang 《哈尔滨工业大学学报:英文版》 EI CAS 2021年第1期71-84,共14页
To improve the utilization rate of steel slag,this paper investigates the expansion behavior of Full Aggregate Steel Slag Concrete(FASSC).Orthogonal experiment was performed to analyze the effects of sand ratio,water-... To improve the utilization rate of steel slag,this paper investigates the expansion behavior of Full Aggregate Steel Slag Concrete(FASSC).Orthogonal experiment was performed to analyze the effects of sand ratio,water-cement ratio,steel slag sand content,replacement particle size of steel slag sand,coarse steel slag content,and replacement particle size of coarse steel slag on the expansion rate of FASSC.Test results demonstrated that the expansion rate of FASSC decreased with a gradual increase in the replacement particle size of steel slag sand or the coarse steel slag content.With a gradual increase in the water-cement ratio or the steel slag sand content,the expansion rate of FASSC first increased and then decreased.As the sand ratio increased,the expansion rate of FASSC first decreased and then increased.Among these,the steel slag sand content and the replacement particle size of steel slag sand significantly affected the expansion rate of FASSC.The mix proportions of SSC for self-stressing CFST and shrinkage compensating SSC were suggested according to the experimental research.Additionally,a formula for approximately predicting the expansion rate of FASSC was proposed based on the single factor weighted fitting. 展开更多
关键词 steel slag concrete orthogonal experiment expansion behavior water-cement ratio sand ratio
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饲养密度和硫辛酸对肉鸡血清指标、行为及骨骼发育的影响 认领
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作者 李文嘉 徐彬 +6 位作者 马慧慧 魏凤仙 王琳燚 付趁 王改利 孙全友 李绍钰 《动物营养学报》 CAS 北大核心 2021年第1期236-247,共12页
本试验旨在研究高饲养密度条件下饲粮中添加硫辛酸(LA)对肉鸡血清指标、行为及骨骼发育的影响。试验选取健康状况良好、体重相近的1530只21日龄爱拔益加(AA)肉鸡,随机分成3组,即常规饲养密度组(ND组,15只/m^2,饲喂基础饲粮)、高饲养密度... 本试验旨在研究高饲养密度条件下饲粮中添加硫辛酸(LA)对肉鸡血清指标、行为及骨骼发育的影响。试验选取健康状况良好、体重相近的1530只21日龄爱拔益加(AA)肉鸡,随机分成3组,即常规饲养密度组(ND组,15只/m^2,饲喂基础饲粮)、高饲养密度组(HD组,18只/m^2,饲喂基础饲粮)和高饲养密度+LA组(HD+LA组,18只/m^2,在基础饲粮在添加300 mg/kg LA),每组6个重复。试验期为3周。结果表明:1)与ND组相比,HD组肉鸡血清钙含量和碱性磷酸酶(ALP)活性显著下降(P<0.05),血清皮质酮(CORT)含量以及还原型辅酶Ⅱ氧化酶(NOX)和髓过氧化物酶(MPO)活性显著上升(P<0.05)。2)与ND组相比,HD组肉鸡行走、梳翅、采食频次与时间占比显著降低(P<0.05),而饮水频次以及饮水和趴卧时间占比显著升高(P<0.05)。3)与ND组相比,高饲养密度显著降低肉鸡胫骨与股骨直径、重量、密度、强度以及钙、磷、灰分和矿物盐含量(P<0.05)。4)与HD组相比,HD+LA组肉鸡血清钙含量和ALP活性显著升高(P<0.05),血清CORT含量以及NOX和MPO活性显著下降(P<0.05);采食频次和时间占比显著增加(P<0.05),饮水频次和趴卧时间占比显著降低(P<0.05);胫骨质量以及钙、磷含量与股骨密度、强度和钙含量显著上升(P<0.05)。综上所述,高饲养密度致使肉鸡发生氧化应激,改变了肉鸡行为,并使肉鸡骨骼质量下降,而饲粮中添加LA能在一定程度上缓解高饲养密度对肉鸡造成的损伤。 展开更多
关键词 饲养密度 硫辛酸 肉鸡 骨骼发育 行为
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Epidural electrical stimulation effectively restores locomotion function in rats with complete spinal cord injury 认领
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作者 Song Wang Li-Cheng Zhang +5 位作者 Hai-Tao Fu Jun-Hao Deng Gao-Xiang Xu Tong Li Xin-Ran Ji Pei-Fu Tang 《中国神经再生研究:英文版》 SCIE CAS 2021年第3期573-579,共7页
Epidural electrical stimulation can restore limb motor function after spinal cord injury by reactivating the surviving neural circuits.In previous epidural electrical stimulation studies,single electrode sites and con... Epidural electrical stimulation can restore limb motor function after spinal cord injury by reactivating the surviving neural circuits.In previous epidural electrical stimulation studies,single electrode sites and continuous tetanic stimulation have often been used.With this stimulation,the body is prone to declines in tolerance and locomotion coordination.In the present study,rat models of complete spinal cord injury were established by vertically cutting the spinal cord at the T8 level to eliminate disturbance from residual nerve fibers,and were then subjected to epidural electrical stimulation.The flexible extradural electrode had good anatomical topology and matched the shape of the spinal canal of the implanted segment.Simultaneously,the electrode stimulation site was able to be accurately applied to the L2–3 and S1 segments of the spinal cord.To evaluate the biocompatibility of the implanted epidural electrical stimulation electrodes,GFAP/Iba-1 doublelabeled immunofluorescence staining was performed on the spinal cord below the electrodes at 7 days after the electrode implantation.Immunofluorescence results revealed no significant differences in the numbers or morphologies of microglia and astrocytes in the spinal cord after electrode implantation,and there was no activated Iba-1~+cell aggregation,indicating that the implant did not cause an inflammatory response in the spinal cord.Rat gait analysis showed that,at 3 days after surgery,gait became coordinated in rats with spinal cord injury under burst stimulation.The regained locomotion could clearly distinguish the support phase and the swing phase and dynamically adjust with the frequency of stimulus distribution.To evaluate the matching degree between the flexible epidural electrode(including three stimulation contacts),vertebral morphology,and the level of the epidural site of the stimulation electrode,micro-CT was used to scan the thoracolumbar vertebrae of rats before and after electrode implantation.Based on the experimental results of gait recover 展开更多
关键词 behavior injury model neurological function rat recovery REGENERATION REPAIR spinal cord
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六安市城乡居民抗生素相关认知和自我用药行为调查 认领
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作者 蒋嫣语 杨雅茹 程静 《中国药房》 CAS 北大核心 2021年第1期98-103,共6页
目的:了解安徽省六安市城乡居民抗生素相关认知水平和自我用药行为,探讨其影响因素,为促进抗生素的合理使用提供参考。方法:采用分阶段抽样法随机选取六安市684位18~80岁的城乡居民作为研究对象,采用自行编制的问卷进行入户调查,调查内... 目的:了解安徽省六安市城乡居民抗生素相关认知水平和自我用药行为,探讨其影响因素,为促进抗生素的合理使用提供参考。方法:采用分阶段抽样法随机选取六安市684位18~80岁的城乡居民作为研究对象,采用自行编制的问卷进行入户调查,调查内容包括一般人口学特征、抗生素相关认知水平、抗生素使用行为及相关影响因素等。结果:共获得有效问卷657份,应答率为96.1%,其中来自城市305份、来自农村352份。657位调查对象中,男性占38.2%、女性占61.8%;年龄(50.30±13.26)岁;受教育水平在小学及以下者占44.7%。7.8%的调查对象能正确认识到抗生素对病毒无效,12.6%知道抗生素耐药性,55.1%认为频繁使用抗生素会降低细菌对其敏感性,23.1%表示知道处方药与非处方药的区别,58.0%可以说出至少1种不需要使用抗生素的情况。7个知识条目得分中,调查地区居民抗生素认知总分不超过3分者占75.3%;城市地区、受教育水平高的人群抗生素认知水平更高。66.5%的调查对象在调查近1年内使用过抗生素,其中61.0%通过医师开具处方获得,50.7%到药店自行购买获得,有13.1%同时使用了以上2种途径。在调查近1年内使用过抗生素的人群中,81.9%表示无需凭处方就能购买抗生素,超过半数(53.8%)有过未咨询医师而自行使用抗生素的行为。在657位调查对象中,49.0%表示在服用抗生素时必须找医师开处方;68.9%表示在服用抗生素时症状好转就停药,19.3%会为了增强疗效而自行加大服药剂量,28.3%在用药时会频繁更换药物。农村地区的居民相比于城市居民更倾向于服用抗生素时由医师开处方[比值比(OR)=1.693,95%置信区间(CI)(1.191,2.407)]。认知得分越高者服用抗生素时必须由医师开出处方的行为率越低[OR=0.882,95%CI(0.785,0.991)],也更倾向于症状好转就停药[OR=1.163,95%CI(1.025,1.319)],男性更倾向于为增强疗效自行加大服药剂� 展开更多
关键词 六安市 自我用药 抗生素 认知 行为
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An integrative multivariate approach for predicting functional recovery using magnetic resonance imaging parameters in a translational pig ischemic stroke model 认领
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作者 Erin E.Kaiser J.C.Poythress +6 位作者 Kelly M.Scheulin Brian J.Jurgielewicz Nicole A.Lazar Cheolwoo Park Steven L.Stice Jeongyoun Ahn Franklin D.West 《中国神经再生研究:英文版》 SCIE CAS 2021年第5期842-850,共9页
Magnetic resonance imaging(MRI)is a clinically relevant,real-time imaging modality that is frequently utilized to assess stroke type and severity.However,specific MRI biomarkers that can be used to predict long-term f... Magnetic resonance imaging(MRI)is a clinically relevant,real-time imaging modality that is frequently utilized to assess stroke type and severity.However,specific MRI biomarkers that can be used to predict long-term functional recovery are still a critical need.Consequently,the present study sought to examine the prognostic value of commonly utilized MRI parameters to predict functional outcomes in a porcine model of ischemic stroke.Stroke was induced via permanent middle cerebral artery occlusion.At 24 hours post-stroke,MRI analysis revealed focal ischemic lesions,decreased diffusivity,hemispheric swelling,and white matter degradation.Functional deficits including behavioral abnormalities in open field and novel object exploration as well as spatiotemporal gait impairments were observed at 4 weeks post-stroke.Gaussian graphical models identified specific MRI outputs and functional recovery variables,including white matter integrity and gait performance,that exhibited strong conditional dependencies.Canonical correlation analysis revealed a prognostic relationship between lesion volume and white matter integrity and novel object exploration and gait performance.Consequently,these analyses may also have the potential of predicting patient recovery at chronic time points as pigs and humans share many anatomical similarities(e.g.,white matter composition)that have proven to be critical in ischemic stroke pathophysiology.The study was approved by the University of Georgia(UGA)Institutional Animal Care and Use Committee(IACUC;Protocol Number:A2014-07-021-Y3-A11 and 2018-01-029-Y1-A5)on November 22,2017. 展开更多
关键词 behavior testing canonical correlation analysis gait analysis Gaussian graphical models ischemic stroke magnetic resonance imaging pig model principal component analysis
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Test on mechanical behavior of SRC L-shaped columns under combined torsion and bending moment 认领
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作者 Chen Zongping Ning Fan +2 位作者 Chen Jianjia Liu Xiang Xu Dingyi 《地震工程与工程振动:英文版》 SCIE EI 2021年第1期161-177,共17页
Investigations of the seismic behavior of steel reinforced concrete L-shaped columns under constant axial compression and cycled bending-shear-torsion load were performed.Six specimens,which considered two parameters,... Investigations of the seismic behavior of steel reinforced concrete L-shaped columns under constant axial compression and cycled bending-shear-torsion load were performed.Six specimens,which considered two parameters,i.e.,the moment ratio of torsion to bending(γ)and the aspect ratio(column length-to-depth ratio,φ),were prepared for the experiment.In this study,the failure process,torsion-displacement hysteresis curves,and flexure-displacement hysteresis curves were obtained.The failure characteristics,mechanical behavior of specimens such as the failure patterns,hysteresis curves,rigidity degradation,ductility and energy dissipation,are analyzed.The experimental research indicated that the major failures of the specimens were bending failure,bending-shear failure and bending-torsion failure as the moment ratio of torsion to bending(γ)increased.The torsion-displacement hysteresis curves were pinched in the middle,formed a slip platform,and the phenomenon of“load drop”occurred after the peak load.The bending-displacement hysteresis curves were plump,which showed that bending capacity of the specimen was better than its torsion capacity.Additionally,the energy dissipation of the specimen was dominated by torsion in the early stage and ultimately governed by the bending moment in the later phase.Test results also indicated that the displacement ductility coefficient and interstory rotation angle of the failure point were less than 3.0 and 1/50,respectively,which means the test specimen performance does not meet the requirement of the Chinese Code for Seismic Design of Buildings(GB 50011-2014)in this respect. 展开更多
关键词 compression-bending-shear-torsion combined action steel reinforced concrete(SRC) L-shaped columns seismic behavior
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Application of modern neuroimaging technology in the diagnosis and study of Alzheimer’s disease 认领
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作者 Hong-Mei Zeng Hua-Bo Han +1 位作者 Qi-Fang Zhang Hua Bai 《中国神经再生研究:英文版》 SCIE CAS 2021年第1期73-79,共7页
Neurological abnormalities identified via neuroimaging are common in patients with Alzheimer’s disease.However,it is not yet possible to easily detect these abnormalities using head computed tomography in the early s... Neurological abnormalities identified via neuroimaging are common in patients with Alzheimer’s disease.However,it is not yet possible to easily detect these abnormalities using head computed tomography in the early stages of the disease.In this review,we evaluated the ways in which modern imaging techniques such as positron emission computed tomography,single photon emission tomography,magnetic resonance spectrum imaging,structural magnetic resonance imaging,magnetic resonance diffusion tensor imaging,magnetic resonance perfusion weighted imaging,magnetic resonance sensitive weighted imaging,and functional magnetic resonance imaging have revealed specific changes not only in brain structure,but also in brain function in Alzheimer’s disease patients.The reviewed literature indicated that decreased fluorodeoxyglucose metabolism in the temporal and parietal lobes of Alzheimer’s disease patients is frequently observed via positron emission computed tomography.Furthermore,patients with Alzheimer’s disease often show a decreased N-acetylaspartic acid/creatine ratio and an increased myoinositol/creatine ratio revealed via magnetic resonance imaging.Atrophy of the entorhinal cortex,hippocampus,and posterior cingulate gyrus can be detected early using structural magnetic resonance imaging.Magnetic resonance sensitive weighted imaging can show small bleeds and abnormal iron metabolism.Task-related functional magnetic resonance imaging can display brain function activity through cerebral blood oxygenation.Resting functional magnetic resonance imaging can display the functional connection between brain neural networks.These are helpful for the differential diagnosis and experimental study of Alzheimer’s disease,and are valuable for exploring the pathogenesis of Alzheimer’s disease. 展开更多
关键词 Alzheimer’s disease behavior BRAIN cognitive impairment FLUORODEOXYGLUCOSE MEMORY neurological function structural magnetic resonance imaging translocator protein
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Material flow behavior and microstructural evolution during refill friction stir spot welding of alclad 2A12-T4 aluminum alloy 认领
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作者 Gao-hui Li Li Zhou +2 位作者 Ling-yun Luo Xi-ming Wu Ning Guo 《矿物冶金与材料学报:英文版》 SCIE EI CAS 2021年第1期131-141,共11页
In this study, we used the stop-action technique to experimentally investigate the material flow and microstructural evolution of alclad 2A12-T4 aluminum alloy during refill friction stir spot welding.There are two ma... In this study, we used the stop-action technique to experimentally investigate the material flow and microstructural evolution of alclad 2A12-T4 aluminum alloy during refill friction stir spot welding.There are two material flow components, i.e., the inward-or outward-directed spiral flow on the horizontal plane and the upward-or downward-directed flow on the vertical plane.In the plunge stage, the flow of plasticized metal into the cavity is similar to that of a stack, whereby the upper layer is pushed upward by the lower layer.In the refill stage, this is process reversed.As such, there is no obvious vertical plasticized metal flow between adjacent layers.Welding leads to the coarsening of S(Al2CuMg) in the thermo-mechanically affected zone and the diminishing of S in the stir zone.Continuous dynamic recrystallization results in the formation of fine equiaxed grains in the stir zone, but this process becomes difficult in the thermo-mechanically affected zone due to the lower deformation rate and the pinning action of S precipitates on the dislocations and sub-grain boundaries, which leads to a high fraction of low-angle grain boundaries in this zone. 展开更多
关键词 refill friction stir spot welding aluminum alloy material flow behavior precipitate evolution dislocation configuration
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Sensor-based physical activity, sedentary time, and reported cell phone screen time: A hierarchy of correlates in youth 认领
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作者 Pedro B.Júdice João P.Magalhães +3 位作者 Gil B.Rosa Duarte Henriques-Neto Megan Hetherington-Rauth Luís B.Sardinha 《运动与健康科学(英文)》 SCIE 2021年第1期55-64,共10页
Background:Evidence on correlates relies on subjective metrics and fails to include correlates across all levels of the ecologic model.We determined which correlates best predict sensor-based physical activity(PA),sed... Background:Evidence on correlates relies on subjective metrics and fails to include correlates across all levels of the ecologic model.We determined which correlates best predict sensor-based physical activity(PA),sedentary time(ST),and self-reported cell phone screen time(CST)in a large sample of youth,while considering a multiplicity of correlates.Methods:Using sensor-based accelerometry,we assessed the PA and ST of 2179 youths.A χ^2 automatic interaction detection algorithm was used to hierarchize the correlates associated with too much ST(>50th percentile),insufficient moderate-to-vigorous PA(MVPA)(<60 min/day),and prolonged CST(≥2 h/day).Results:Among youth 1014 years old,the correlates for being inactive consisted of being a girl,not having sport facilities in the neighborhood,and not perceiving the neighborhood as a safe place,whereas in the youth 1518 years old,the correlate for being inactive was not performing sports(9.7%chance of being active).The correlates for predicting high ST in the younger group was not performing sports(55.8%chance for high ST),and in the older group,the correlates were not owning a pet,perceiving the neighborhood as safe,and having inactive parents(63.7%chance for high ST).In the younger group,the greatest chances of having high CST were among those who were in the last elementary school years,who were girls,and who did not have friends in the neighborhood(73.1%chance for high CST),whereas in the older group,the greatest chance for having high CST was among those who were girls and had a TV in the bedroom(74.3%chance for high CST).Conclusion:To counteract ST and boost MVPA among youths,a specific focus on girls,the promotion of sport participation and facilities,neighborhood safety,and involvement of family must be prioritized. 展开更多
关键词 Adolescents Environment Objective Sedentary behavior Socioecologic model
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新型冠状病毒肺炎集中隔离医学观察点工作人员防护知信行情况调查分析 认领
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作者 张书怡 孙伟 +3 位作者 李凤玲 潘洁 张娴 徐青 《上海医药》 CAS 2021年第2期17-19,53,共4页
目的:了解上海市徐汇区5家集中隔离医学观察点工作人员的新型冠状病毒肺炎防护认知、态度和行为情况。方法:于2020年6月27日-7月6日通过便利抽样方法选取上海市徐汇区5家集中隔离医学观察点的264名工作人员为调查对象,通过电子形式发放... 目的:了解上海市徐汇区5家集中隔离医学观察点工作人员的新型冠状病毒肺炎防护认知、态度和行为情况。方法:于2020年6月27日-7月6日通过便利抽样方法选取上海市徐汇区5家集中隔离医学观察点的264名工作人员为调查对象,通过电子形式发放《基层医务人员新型冠状病毒肺炎防护知、信、行调查分析》问卷,共发放问卷264份,回收264份,问卷有效回收率为100.0%。结果:19.3%的工作人员不清楚人群普遍易感新型冠状病毒肺炎,22.7%的工作人员不知道哪些方法可以有效灭活新型冠状病毒,36.4%的工作人员不知道抗生素是否能治疗新型冠状病毒肺炎。45.4%的工作人员对新型冠状病毒肺炎感到很恐惧,42.0%的工作人员认为当地新型冠状病毒肺炎防疫力度过当,影响了正常生活。近九成的工作人员能够根据岗位调动采取相应级别的防护措施,94.3%的工作人员能够严格执行新型冠状病毒肺炎防控规定。28.4%的工作人员不确定自己是否能够做到尽量不去公共场合,12.5%的工作人员不确定自己是否能够通过心理自我调适缓解恐惧、紧张和焦虑的情绪。结论:通过开展新型冠状病毒肺炎防护知识培训、提供心理支持及人文关怀、完善工作细节等措施进行科学、系统、规范的集中隔离医学观察管理工作。 展开更多
关键词 新型冠状病毒肺炎 集中隔离医学观察点 知识-态度-行为
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产权安全性、产权认知与土地流转高意愿低行为 认领
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作者 段静琪 郭焱 朱俊峰 《华中农业大学学报:社会科学版》 北大核心 2021年第1期156-164,181,182,共11页
基于全国25省农户微观调查数据,运用Probit模型和Tobit模型,探讨产权安全性、产权认知对农户土地流转高意愿低行为的作用机制。研究表明,土地流转意愿向行为转化需要一系列条件来支撑。当地权稳定性较高时,农户的土地流转意愿可以顺利... 基于全国25省农户微观调查数据,运用Probit模型和Tobit模型,探讨产权安全性、产权认知对农户土地流转高意愿低行为的作用机制。研究表明,土地流转意愿向行为转化需要一系列条件来支撑。当地权稳定性较高时,农户的土地流转意愿可以顺利转化成行为,反之则不能;确权使得农户的土地产权更加明晰,进而可以促进转入户土地流转意愿转化为行为,阻碍转出户土地流转意愿转化为行为;与此同时,农户自评的村级流转管制也产生与确权相同的效果。据此,提出应当在维护地权稳定性的基础上,规范土地经营权交易市场,发挥村集体优势,为农户进一步参与土地流转市场创造有利条件。 展开更多
关键词 产权安全性 产权认知 土地流转 意愿 行为
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PCC0104007在精神分裂症大鼠模型中的药学研究 认领
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作者 岳馨 刘如梦 +1 位作者 朱晓音 田京伟 《烟台大学学报:自然科学与工程版》 CAS 2021年第1期42-47,共6页
为了评估PCC0104007作为精神分裂症治疗剂的潜力,采用MK-801和5-HTP诱导的大鼠模型进行体内药效学研究。结果表明,PCC0104007可减轻MK-801诱导的大鼠高自发活动。PCC0104007可显著抑制5-HTP诱导的甩头反应。在NOR试验和MWM试验中PCC0104... 为了评估PCC0104007作为精神分裂症治疗剂的潜力,采用MK-801和5-HTP诱导的大鼠模型进行体内药效学研究。结果表明,PCC0104007可减轻MK-801诱导的大鼠高自发活动。PCC0104007可显著抑制5-HTP诱导的甩头反应。在NOR试验和MWM试验中PCC0104007显著改善了MK-801慢性给药引起的认知症状。Golgi染色结果表明,PCC0104007可显著缓解MK-801造成的mushroom树突棘密度降低。认知能力的提高可以通过增加蘑菇棘的数量来实现。PCC0104007与一线抗精神病药物阿立哌唑相比非劣势,是精神分裂症新的候选药物。 展开更多
关键词 精神分裂症 MK-801 认知症状 行为学
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A video camera recording method for measuring terminal velocity of seed dispersal by wind 认领
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作者 Minghu Liu Zhiming Xin +9 位作者 Zhi Su Yingming Zhao Xinle Li Zhimin Liu Mariano ACony Wei Liang Xuanping Qin Jianqiang Qian Xue Cui Quanlai Zhou 《林业研究:英文版》 SCIE CAS 2021年第1期81-90,共10页
An accurate and convenient method is essential for measuring the terminal velocity of seeds dispersed by wind.Systematic and random errors produced by existing methods lower the accuracy and convenience in determining... An accurate and convenient method is essential for measuring the terminal velocity of seeds dispersed by wind.Systematic and random errors produced by existing methods lower the accuracy and convenience in determining seed terminal velocity.In this study,a video camera was used to record the falling process of forty-one species of wind-borne seed with eight appendage structures and seven aerodynamic behaviors in a settling tower at a speed of 50 frames per second(fps).The videos were analyzed by Quick Time Player to determine seed acceleration height,acceleration time,and terminal velocity.The results showed that acceleration height and time,terminal velocity,and the diff erence between terminal velocity and descent velocity(DTD)increased with wing loading.Compared with dropping methods,the camera recording method eliminated the eff ect of acceleration and corrected seed terminal velocity.Based on wing loading,release heights were determined for accurate measurement of terminal velocity of diff erent seeds.This method,due to its inexpensive equipment,high accuracy,easy observation and operation,can be applied to measure the terminal velocity of wind dispersed seeds,and provides a promising method in exploring the dispersal process of seeds. 展开更多
关键词 Acceleration height Acceleration time Settling tower Aerodynamic behavior Appendage structures
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La^3+ doped LiCo0.25Zn0.25Fe2O4 spinel ferrite nanocrystals:Insights on structural,optical and magnetic properties 认领
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作者 M.I.A.Abdel Maksoud Ahmed El-Ghandour +7 位作者 A.H.Ashour M.M.Atta Soraya Abdelhaleem Ahmed H.El-Hanbaly Ramy Amer Fahim Said M.Kassem M.S.Shalaby A.S.Awed 《稀土学报:英文版》 SCIE EI CAS 2021年第1期75-82,I0003,共9页
This paper addresses the manipulation of structural,morphology,optical and magnetic properties of LiCo0.25Zn0.25Fe2 O4 ferrite via incorporation of different proportions of La^3+at the expense of iron ions using a sol... This paper addresses the manipulation of structural,morphology,optical and magnetic properties of LiCo0.25Zn0.25Fe2 O4 ferrite via incorporation of different proportions of La^3+at the expense of iron ions using a sol-gel method.The samples were characterized using the X-ray diffraction technique(XRD),Fourier transform infrared(FT-IR)spectroscopy,the energy dispersive X-ray spectra(EDX),inductively coupled plasma optical emission spectroscopy(ICP-OES),high resolution scanning electron microscopy(SEM),Brunauer-Emmett-Teller(BET)surface area analysis,ultraviolet-diffuse reflectance spectroscopy(UV-DRS),and vibrating sample magnetometer(VSM)technique.The Rietveld refinements of the samples indicate that at higher concentrations of La^3+,nanostructures with dual phase,i.e.cubic spinel and orthorhombic LaFeO3 perovskite with space group(Pbnm)appear.Optical studies show that the energy band gap(Eg)of the bare LiCo0.25Zn0.25Fe2 O4 ferrite sample(2.18 eV)reaches up to 2.47 eV at x=0.06 and above this concentration,it drops sharply to 2.00 eV.Although the saturation magnetization and the coercivity of LiCo0.25Zn0.25LaxFe2-xO4 are lower than that of LiCo0.25Zn0.25Fe2 O4 NPs.Overall,the superparamagnetic nature and low values of saturation magnetization and coercivity of LiCo0.25Zn0.25LaxFe2-xO4 NPs are suitable to be applied in transformers core. 展开更多
关键词 Li-Co-Zn ferrite Superparamagnetic nature Optical properties Magnetic behavior Transformers core Rare earths
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