The cultural Red King effect

Why do minority groups tend to be discriminated against when it comes to situations of bargaining and resource division? In this article, I explore an explanation for this disadvantage that appeals solely to the dynamics of social interaction between minority and majority groups—the cultural Red King effect (Bruner, 2017). As I show, in agent-based models of bargaining between groups, the minority group will tend to get less as a direct result of the fact that they frequently interact with majority group members, while majority group members meet them only rarely. This effect is strengthened by certain psychological phenomenon—risk aversion and in-group preference—is robust on network models, and is strengthened in cases where preexisting norms are discriminatory. I will also discuss how this effect unifies previous results on the impacts of institutional memory on bargaining between groups.     

Hydrodynamic lift of vesicles and red blood cells in flow — from Fåhræus & Lindqvist to microfluidic cell sorting

Hydrodynamic lift forces acting on cells and particles in fluid flow receive ongoing attention from medicine, mathematics, physics and engineering. The early findings of Fåhræus & Lindqvist on the viscosity change of blood with the diameter of capillaries motivated extensive studies both experimentally and theoretically to illuminate the underlying physics. We review this historical development that led to the discovery of the inertial and non-inertial lift forces and elucidate the origins of these forces that are still not entirely clear. Exploiting microfluidic techniques induced a tremendous amount of new insights especially into the more complex interactions between the flow field and deformable objects like vesicles or red blood cells. We trace the way from the investigation of single cell dynamics to the recent developments of microfluidic techniques for particle and cell sorting using hydrodynamic forces. Such continuous and label-free on-chip cell sorting devices promise to revolutionize medical analyses for personalized point-of-care diagnosis. We present the state-of-the-art of different hydrodynamic lift-based techniques and discuss their advantages and limitations.     

Development and validation of a rapid HPLC method for the determination of five banned fat-soluble colorants in spices using a narrow-bore monolithic column

This work reports a fast and simple liquid chromatographic method for the simultaneous determination of five banned fat-soluble synthetic colorants, namely Sudan I-IV and Para-Red, in spice samples. The analytes were successfully separated isocratically in less than 5 min on the new narrow bore monolithic column, FastGradient^® Chromolith (50 mm × 2.0 mm i.d.) using a mobile phase of 0.1% (v/v) HCOOH/acetonitrile (35/65%, v/v) at a flow rate of 1.5 mL min⁻¹. All colorants were detected at 506 nm. The main parameters (mobile phase composition, flow rate, injection volume) affecting the separation were studied. The proposed method was thoroughly validated in terms of linearity, LODs, precision and accuracy. The method was applied to the determination of the studied azo-dyes in various spices (paprika, chilli and mixed spice powders) after ultrasound-assisted extraction. Satisfactory recoveries, ranging from 92% to 109% were obtained.     

甲酚红褪色分光光度法测定芬布芬的研究及其应用

在pH9.00的tris-HCl缓冲溶液中,甲酚红与芬布芬反应形成离子缔合物,使甲酚红溶液褪色.实验结果表明:最大褪色波长位于569.0nm,芬布芬浓度在0.05086～10.17μg/mL范围内遵循比尔定律,回归方程为ΔA=0.1702c+0.0107(c=μg/mL),相关系数为r=0.9996,表观摩尔吸光系数为4.537×104 L·mol-1·cm-1.据此建立了测定药物制剂和生物样品中芬布芬含量的褪色分光光度法,样品测定平均回收率为97.97%～101.6%.     

Insight into Amyloid Formation Using Congo Red as the Electrochemical Probe

The amyloid‐β (Aβ) aggregation pathway is an important target for the discovery of drugs that can prevent or delay the onset of Alzheimer’s disease (AD). The electrochemistry of Congo Red (CR) represents a particularly promising tool for screening of Aβ‐binding therapeutics in a rapid and cost‐effective format. The results of the differential pulse voltammetry (DPV) measurements were confirmed using simultaneous UV‐vis analysis of the same incubated Aβ samples. The early changes in the electrochemical signals were attributed to the interaction of the Aβ oligomers with CR. The electrochemical approach, in principle, allowed monitoring small molecule‐Aβ interactions on the time scale of aggregation.     

结合DEM的红边-近红外植被指数提取城市植被信息

随着生活水平的不断提高,城市植被已成为衡量城市宜居性的重要标准之一,对城市生物多样性评估和保护起到非常重要的作用。因此,合理规划城市植被是解决环境问题和提高生活质量的重要手段。因此,城市植被的提取和监测成为重中之重的任务。目前,城市植被提取一方面受到地域和物种的影响,另一方面也受到地形和建筑物阴影的影响。为解决上述问题,提出了一种结合数字高程模型(DEM)的红边-近红外植被指数模型（RENVI）。首先选取了3景经过辐射定标和大气校正的具有红边波段、且光谱和空间分辨率较高的Worldview-3遥感影像;然后,根据红边波段对于植被具有较高的敏感性,且红边范围内的光谱数据与反映植被生长状况的参数有较好的相关关系原理,采用DEM模型和红边波段光谱差异,有效去除地形和建筑物阴影;最后,在可见光波段范围内建立红边光谱-近红外光谱构建特征空间,构建了红边-近红外植被指数模型,同时与归一化植被指数（NDVI）和增强型植被指数（EVI）进行城市植被提取的定性和定量对比分析。定性分析是利用真实植被影像参考图与模型提取植被影像进行视觉分析;后者是采用用户精度、生产者精度、总体精度和Kappa系数进行量化分析。定性分析表明：NDVI和EVI提取城市植被,由于建筑和道路像元混淆在植被中,产生了错分和漏分的问题。RENVI较好地消除了阴影像元与植被像元混淆问题,能准确的提取城市植被,减少了冗余度,增加了植被指数的信息量。定量分析表明：RENVI模型较NDVI和RVI能够准确提取城市植被,3景影像总体精度分别为89%,81.4%和91.8%,Kappa系数分别为0.852 8,0.791 3和0.905 2。综上所述,该方法有效提高了城市植被提取精度,并取得了较好的提取视觉效果。     

延安时期红色文献的红外光谱无损检测研究

延安是中国共产党领导革命的中心和战略总后方,是革命的红色摇篮。延安时期出版了大量具有历史、文化以及教育意义的红色文献,这些红色文献记载了中国共产党波澜壮阔的发展历程,也反映了延安时期不断发展的科技生产水平与独特的制浆造纸工艺,具有重要的研究价值。然而,延安时期出版的红色文献虽距今不到百年时间,但其保存现状不容乐观,普遍存在纸张老化、焦脆易碎等问题,大量文献急需科学检测与修复保护,以延长其保存寿命。目前,针对延安时期红色文献的检测研究仍存在较大空白。考虑到红色文献的珍贵性与特殊性,应当尽可能选择无损检测方法对其分析检测。基于衰减全反射-傅里叶变换红外光谱法（ATR-FTIR）,以木素1 510 cm-1处特征峰与纤维素1 030 cm-1处特征峰的强度作为定量依据,建立了造纸原料与红色文献纸张中木素相对含量的无损检测方法。通过检测不同碱强度与碱浓度处理后的构皮、苦竹与杨木的木素含量,考察了制浆过程中碱处理条件对造纸原料脱木素程度的影响,同时体现了红外光谱法测定木素相对含量的普适性。以复旦大学图书馆藏的76册延安时期红色文献为研究对象,分析了红色文献的纸张木素含量与纸张pH值以及纸张氧化度的相互关系。结果表明,木素相对含量高于25%的红色文献,其纸张pH集中在3～4之间且纸张氧化度较高,文献整体保存状况堪忧;而木素相对含量低于25%的红色文献,其纸张氧化度与酸度较低,文献整体保存情况较好。以上结果验证了红外光谱无损检测法用于延安时期红色文献木素含量分析的可行性,并结合纸张氧化度与酸度数据提出了纸张木素含量的合适范围,为制浆造纸中植物原料的脱木素过程提供参考。拓展了红外光谱法在红色文献无损检测中的应用范围,以期为延安时期红色文献的修复与保护研究提供科学依据。     

《红楼梦》的美学意蕴

《红楼梦》以大观园为核心场景,以贾宝玉为主人公,以宝黛之恋为贯穿全书的红线。本文从大观园、贾宝玉和宝黛之恋三个意象层面探讨《红楼梦》的美学意蕴。《红楼梦》在虚实交融的叙事中,以极切实又极奇幻的笔法,展示了一出以贾宝玉为中心意象的凄美而炽烈的人生戏剧。在熔铸多元文化精神的前提下,对庄子哲学的生命精神的阐发,是《红楼梦》的美学意蕴之真谛。本文认为,阅读《红楼梦》,解析贾宝玉,都须从反面−即庄子哲学的“无用之用”−着眼。这无用之用,就是自我生命的真实和自由,扩大讲,就是世界的生机和无限。     

A novel off-on fluorescent probe for specific detection and imaging of cysteine in live cells and in vivo

Cysteine(Cys) plays a pivotal role in many physiological and pathological processes,including detoxification and protein synthesis.The abnormal levels of Cys are linked to many diseases.In this study,a novel red-emitting off-on fluorescent probe Cys-TCF was masterly constructed for discriminative detection of Cys.After a series of experimental assessment,Cys-TCF displayed higher selectivity and sensitivity for Cys over other biothilols with a low detection limit(0.04 μmol/L).More notably,the pro...     

冬小麦生长期光谱变化特征与叶绿素含量监测研究

在分析冬小麦生长期冠层反射光谱和叶绿素含量变化特征的基础上,对二者之间的相关性进行了研究。表明从小麦拔节期开始,冠层反射光谱在可见光区(400～750 nm)的反射率先降低而后升高,以孕穗期反射率最低;在近红外区(750～1 000 nm)冠层反射率由拔节期至孕穗期反射率降低,然后开始上升。扬花期上升至最高点后又开始下降,直至乳熟期降至最低。冬小麦冠层反射率与叶绿素含量相关分析结果表明,冬小麦拔节期和孕穗期二者呈正相关,扬花期二者呈负相关;整个生长期中,孕穗期可见光区552 nm处反射率与叶绿素含量相关系数最大达0.89。依据冬小麦生长期冠层反射光谱红边拐点位置,分别建立了拔节期叶绿素含量线性检测模型(R2=0.92)和孕穗期二项式模型(R2=0.91),用于冬小麦叶绿素含量的无损检测是可行的。