~(60)Co辐射对在体红细胞微观流变特性的影响

采用＾６０Ｃｏ大剂量全身均匀急性辐射的方法,使动物造血系统受到严重破坏,血造机能大大闰弱,在大约３０天时间内,循环系统中的红细胞计数明显下降,从而造成一种辐射贫血的动物模型,以便时间内连续研究＾６０Ｃｏ大剂量辐射对在体红细胞流变特性的影响。采用一种在低粘切变流场中能将红细胞变形指数ＤＩ分角为取向指数（ＤＩ）ｏｒ和小变形指数（ＤＩ）ｄ的新型激光衍射法,研究了＾６０Ｃｏ大剂量辐射对在体红细胞变形性、全     

白蛋白对低粘切变流中的红细胞流变特性的影响

用一种新型激先衍射法,研究了白蛋白对低粘切交流动中红细胞取向的影响。所得结果表明,当白蛋白浓度小于０．０４ｇ／Ｌ时,测得的取向指数（ＤＩ）ｏｒ随蛋白浓度迅速增加,在白蛋白浓度等于０．０４ｇ／Ｌ时,其取向指数（ＤＩ）ｏｒ达到最大值,以后又随白蛋白浓度的增加而很快降低到一稳定值（白蛋白浓度大于０．５ｇ／Ｌ时）。同时作者从流变学观点对上述实验结果作了解释,并通过实验证明了取向指数可用于描述红细胞变形性,从而证明了在一定浓度下（０．０４ｇ／Ｌ）白蛋白有增加红细胞变形性,保持红细胞双凹圆盘形的功能。该研究提示我们,在用此新型激光衍射法时,必须在介质中加入适量的白蛋白（０．０４ｇ／Ｌ）。     

用激光衍射法研究红细胞在低粘切变流场中的取向和变形及其生物物理意义

采用一种新型激光衍射法 ,对不同浓度WGA处理的红细胞进行测量 ,进一步研究了红细胞在低粘切变流场中的流变特性 .通过用DPH探剂标记的荧光偏振法 ,用马来酰亚胺 (MSL)标记的电子顺磁共振法 ,揭示了新激光衍射法所描写的红细胞在低粘切变流场中取向指数 (DI_or)与等容小变形指数 (DI_d)的生物物理意义     

红细胞衰老过程中微观流变学行为的研究

作者在用抗体诱发动物急性溶血的方法建立的红细胞在体同步衰老模型的基础上,对红细胞衰老过程中的微观流变学行为进行了研究。用激光衍射法对高粘悬浮介质（ＰＶＰ）和低粘悬浮介质（ＰＢＳ）流场中的微观流变学指标ＤＩ、ＩＤＩ、（ＤＩ）ｄ、（ＤＩ）ｏｒ进行测量,结果显示四项指标随红细胞年龄的增加均呈下降趋势,但并不呈线性关系。表现为在生命周期中的前期变化较小,后期变化较大。提示老化过程中红细胞的流变学行为的变化主要发生在其生命过程的后半期。但各指标变化的规律不尽相同。与本室以往的研究结果进行比较,这些结果提示,在红细胞生命的初期,其膜的力学性质基本不变。而整个红细胞生命过程中红细胞力学性质的变化,可能来自红细胞的形状、胞浆及膜的粘弹性等多因素的影响     

60Co辐射对网织红细胞微观流变学特性的影响

采用60Co大剂量全身均匀急性辐射的方法,造成一种辐射贫血的动物模型.以便在几天内连续研究60Co辐射对新生的网织红细胞及红细胞流变学特性的影响.采用一种在低粘切变流场中能将红细胞变形指数DI分解为取向指数(DI)or和小变形指数(DI)d的新型激光衍射法,对网织红细胞及红细胞的变形指数、取向指数、综合变形指数(IDI)等血液流变学特性参数进行测量,发现在60Co大剂量辐射后,新生的网织红细胞及红细胞流变学特性存在明显异常.将这种60Co辐射造成的贫血模型与文宗曜等提出的用抗体诱导的大量同步化的球形红细胞贫血模型相比较,后者更具有明显的优点.同时为研究辐射对血液流变特性的影响及正确地挑选红细胞衰老模型提供了理论与实验的基础.     

红细胞在钙离子和离子载体A23187作用下的流变特性研究

用新激光衍射法研究了钙离子及离子载体A23187对红细胞流变特性的影响.用不同浓度的钙离子及离子载体A23187分别处理红细胞后,测量其取向指数和小变形指数.结果表明离子载体A23187较细胞外钙离子浓度对红细胞流变特性的影响更大.而且,最大取向指数和最大小变形指数随着钙离子及离子载体A23187浓度的增加而降低.离子载体A23187浓度增加导致红细胞变形能力明显降低.     

激光生物学技术研究高脂血症大鼠红细胞变形能力改变及其机制

目的:通过研究红细胞膜流动性以及红细胞骨架结构的改变,进一步探讨高脂血症大鼠红细胞变形能力改变的机制。方法:16只Wistar大鼠随机分为两组:高血症组和对照组。高脂组给予高脂饮食。16周后,腹主动脉采血,采用酶比色法检测血浆甘油三脂、胆固醇含量;并利用激光衍射法测定红细胞变形指数、取向指数,荧光偏振法测定红细胞膜流动性,激光共聚焦显微镜观测红细胞骨架改变和红细胞F-actin的含量。结果:发现高脂血症大鼠红细胞的变形指数、取向指数以及红细胞膜的流动性显著降低(P<0.05),红细胞形态和骨架发生改变,F-actin含量显著降低(P<0.05)。结论:高脂血症大鼠红细胞变形能力降低与红细胞膜结构改变有一定的关系。     

树种保护酶活性与PV曲线水分参数变化的关系

在水分胁迫条件下,树种间ＳＯＤ（超氧化物歧化酶）活性与其ＤＩ（抗旱性指数）值的排序结果基本一致,表明ＳＯＤ活性变化所反映的树木抗氧化伤害力大小与ＰＶ曲线水人参数所指示的树木耐旱性强弱具有密切的正相关性。但是树种间ＰＯＤ（过氧化物酶）活性变化与ＤＩ值之间的关系则不密切。其原因：①清除Ｈ２Ｏ２的抗氧化酶类较多（ＰＯＤ只是这一）;②某些树种中且存在歧化Ｈ２Ｏ２的抗氧化剂。在水分胁迫阶段,海红的ＤＩ值最大     

60Co辐射对网织红细胞微观流变学特性的影响

采用 ⁶⁰Co大剂量全身均匀急性辐射的方法,造成一种辐射贫血的动物模型.以便在几天内连续研究 ⁶⁰Co辐射对新生的网织红细胞及红细胞流变学特性的影响.采用一种在低粘切变流场中能将红细胞变形指数DI分解为取向指数（DI）_or和小变形指数（DI）_d的新型激光衍射法,对网织红细胞及红细胞的变形指数、取向指数、综合变形指数（IDI）等血液流变学特性参数进行测量,发现在 ⁶⁰Co大剂量辐射后,新生的网织红细胞及红细胞流变学特性存在明显异常.将这种 ⁶⁰Co辐射造成的贫血模型与文宗曜等提出的用抗体诱导的大量同步化的球形红细胞贫血模型相比较,后者更具有明显的优点.同时为研究辐射对血液流变特性的影响及正确地挑选红细胞衰老模型提供了理论与实验的基础.     

全血滤过法测定红细胞变形性的意义

有关红细胞变形性的检验指标,已受到临床的重视。测定红细胞变形性的方法也越来越多。最近,Rohmor 报告目前检查红细胞的变形性的方法有流变镜法、激光衍射法、高速离心法、细胞流过时间分析法、微吸管法、微孔滤膜法和凝胶过滤法等。目前,在国内大多数基层医疗单位采     

Biophysical meanings of orientation and deformation of RBCs in shear flow field of low viscosity with new Ektacytometry

ＥｋｔａｃｙｔｏｍｅｔｒｙｍｅａｓｕｒｉｎｇＲＢＣｄｅｆｏｒｍａｂｉｌｉｔｙｗａｓｆｉｒｓｔｄｅｖｅｌｏｐｅｄｂｙＢｅｓｓｉｓｅｔａｌ.ｉｎ1975[1].Ｔｈｉｓｔｅｃｈｎｉｑｕｅｈａｓｂｅｅｎｗｏｒｌｄｗｉｄｅａｃｃｅｐｔｅｄｎｏｗ.Ｈｏｗｅｖｅｒ,ｔｈｅｍｅａｎｉｎｇｏｆｄｅｆｏｒｍａｔｉｏｎｉｎｄｅｘ(ＤＩ)ｍｅａｓｕｒｅｄｗｉｔｈｔｈｉｓｍｅｔｈｏｄｉｓｓｔｉｌｌｗｏｒｔｈｓｔｕｄｙｉｎｇ.ＴｈｅｔｒａｄｉｔｉｏｎａｌＥｋｔａｃｙｔｏｍｅｔｒｙｕｓｅｓｓｕｓｐｅｎｄｉｎｇｍｅｄｉｕｍｏｆｈｉｇｈｖｉ…     

Low viscosity Ektacytometry and its validation tested by flow chamber.

The flow chamber was used to observe the orientation and small deformation of red blood cells (RBCs) in a shear flow of low viscosity. With the aid of computer software, the percentage of RBCs oriented to the C=0 orbit (OI)(F) and the degree of deformation (DI)(F) of such RBCs were calculated by processing the photographs. It was found that these parameters were highly correlated, respectively, to the orientation index (OI)(E) and the small deformation index (DI)(E) obtained by our low viscosity Ektacytometry (LVE). Thus, our flow chamber research has provided direct evidence to validate the use of this low viscosity Ektacytometry. Although there are relative merits for the flow chamber method using low viscosity medium, the LVE is more likely to be applied in clinic for its simplicity and convenience.     

The measurement of shear modulus and membrane surface viscosity of RBC membrane with Ektacytometry: a new technique

A new technique is proposed to estimate the shear modulus (mu) and membrane surface viscosity (eta(m)) of red blood cell (RBC). Theoretical formulae for finding these two parameters are first derived based on the force balance on a RBC in a flow field of low viscosity. Different types of Ektacytometry are then used to measure relevant quantities. The obtained values (mu=6.1 x 10(-6)N/m, eta(m)=8.8 x10 (-7)Ns/m for normal RBC) are consistent with those previously found by micropipette technique and in AC electric field. The present technique is, however, much easier to operate and more advantageous in reflecting the average properties of a large quantity of RBCs, and it is much cheaper to be applied in clinical practice than any other method of measuring the two parameters. The sensitivity of the technique is demonstrated by testing RBCs treated with glutaraldehyde of different concentrations. This technique was demonstrated by the flow chamber.     

An automated cell analysis sensing system based on a microfabricated rheoscope for the study of red blood cells physiology

An automated rheoscope has been developed, utilizing a microfabricated glass flow cell, high speed camera and advanced image-processing software. RBCs suspended in a high viscosity medium were filmed flowing through a microchannel. Under these conditions, RBCs exhibit different orientations and deformations according to their location in the velocity profile. The rheoscope system produces valuable data such as velocity profile of RBCs, spatial distribution within a microchannel and deformation index (DI) curves. The variation of DI across the channel height, due to change in shear stress, was measured carrying implications for diffractometry methods. These curves of DI were taken at a constant flow rate and cover most of the relevant shear stress spectrum. This is an improvement of the existing techniques for deformability measurements and may serve as a diagnostic tool for certain blood disorders. The DI curves were compared to measurements of the flowing RBCs velocity profile. In addition, we found that RBCs flowing in a microchannel are mostly gathered in the center of the flow and maintain a characteristic spatial distribution. The spatial distribution in this region changes slightly with increasing flow rate. Hence, the system described, provides means for examining the behavior of individual RBCs, and may serve as a microfabricated diagnostic device for deformability measurement.     

网织红细胞成熟过程中膜剪切弹性模量及表面粘度的改变

用鸡抗兔血清的抗体使兔造成急性溶血性贫血的方法,诱发兔体内同步生长的新生网织红细胞,用文宗曜等提出的一种测量红细胞膜剪切弹性模量及表面粘度的新方法——新型激光衍射法,连续72h监测经过不同发育阶段的网织红细胞的小变形指数和变形恢复过程(即松弛过程)中变形恢复到最大值一半的时间(即变形恢复半时间,t0.5),将测得的结果分别代入红细胞膜的剪切弹性模量公式和表面粘度公式。计算出不同发育阶段的网织红细胞的膜剪切弹性模量和表面粘度,发现网织红细胞在转变为成熟红细胞的过程中,其膜剪切弹性模量和表面粘度有明显改变。这对研究由于贫血等原因造成的网织红细胞增多情况下全血的微观流变学特性有重要的-临床意义,同时对新生网织红细胞在转化过程中膜的剪切弹性模量和表面粘度的变化规律加以系统研究,具有重要的基础理论研究价值。     

A new red blood cell filtration device with improved time resolution and its application to the impaired RBC deformability in the diabetic ob/ob mouse

A new filtration device and blood handling technique for the assessment of RBC deformability in small blood samples is described and used to study RBC deformability in adult obese-hyperglycemic ob/ob-mice and normoglycemic controls. The new filtration device was designed to improve the time resolution during RBC incubation. Test and control RBC suspensions were directly filtered from two identical incubation chambers under a constant pressure of 1200 Pa. Nuclepore filters (3 microns) were mounted on top of several standard test tubes into which the filtrate was subsequently collected and weighed. Because the RBCs were resuspended to a very low (0.01%) hematocrit, the average number of RBCs passing each pore was less than 10. Therefore, any detectable difference must reflect the physical properties of RBCs, e.g. shape or viscoelasticity, whereas the role of white blood cells is negligible. When ob/ob-mouse RBCs were studied with the new technique they showed impaired filtrability as compared with control RBCs, both when incubated without glucose and with glucose present at the same concentration as that recorded in the RBC donating mouse.     

Theoretical model and experimental study of red blood cell (RBC) deformation in microchannels

The motion and deformation of red blood cells (RBCs) flowing in a microchannel were studied using a theoretical model and a novel automated rheoscope. The theoretical model was developed to predict the cells deformation under shear as a function of the cells geometry and mechanical properties. Fluid dynamics and membrane mechanics are incorporated, calculating the traction and deformation in an iterative manner. The model was utilized to evaluate the effect of different biophysical parameters, such as: inner cell viscosity, membrane shear modulus and surface to volume ratio on deformation measurements. The experimental system enables the measurement of individual RBCs velocity and their deformation at defined planes within the microchannel. Good agreement was observed between the simulation results, the rheoscope measurements and published ektacytometry results. The theoretical model results imply that such deformability measuring techniques are weakly influenced by changes in the inner viscosity of the cell or the ambient fluid viscosity. However, these measurements are highly sensitive to RBC shear modulus. The shear modulus, estimated by the model and the rheoscope measurements, falls between the values obtained by micropipette aspiration and laser trapping. The study demonstrates the integration of a theoretical model with a microfabricated device in order to achieve a better understanding of RBC mechanics and their measurement using microfluidic shear assays. The system and the model have the potential of serving as quantitative clinical tools for diagnosing deformability disorders in RBCs.     

高光谱植被指数与水稻叶面积指数的定量关系

基于不同水稻品种、施氮水平和不同生育期下的大田试验,确立了水稻叶面积指数（LAI）与冠层光谱特征参数的定量关系.结果表明：水稻叶面积指数与部分高光谱植被指数存在良好的相关性,其中原始光谱组成的2波段差值指数（DI）形式相关性最好,其次为比值（RI）和归一化（NI）植被指数.相关最好的原始光谱植被指数是由近红外波段组成的差值指数DI(854,760),相关最好的一阶导数光谱植被指数是红光和近红外光组成的导数差值指数DI(D₆₇₆, D₇₇₈),但总体上导数光谱指数不如原始光谱指数与LAI关系密切.独立试验数据检验结果表明,以差值指数DI(854,760)为变量建立的水稻LAI监测模型具有较好的表现,可用于水稻LAI的估测.     

Areal distribution of the discomfort index in Israel

The areal distribution of monthly mean values of the Discomfort Index (DI) in Israel is presented for key hours of the day for the summer half of the year. The DI as used in this study, is defined as the arithmetic average of the dry-bulb and wet-bulb temperature (°C), a value of 24 representing conditions at which half the people would feel uncomfortable. Data were collected from 95 meteorological stations situated in different parts of Israel. The raw data consisted of daily values of dry and wet-bulb temperatures for the hours 08:00, 14:00, and 20:00h for the years 1963–1972. Maximum values of the monthly mean DI in Israel generally occur in August. Geographically, the number of days of the year with DI greater than 24 ranges from 30 in the mountain regions, to 120 in the coastal plain, to 180 in the Jordan Valley, Dead Sea, and Arava regions. The dominant control of the observed distribution of DI in Israel appears to be topography. The DI is not a good measure of human discomfort for particularly hot and dry conditions, typical of those occurring during Sharav weather conditions. For such conditions, a new index was developed based on the difference between the dry-bulb and wet-bulb temperatures. The mean areal distributions of this difference index as well as that of the DI are presented for typical intense Sharav conditions. The new difference index appears to better represent discomfort during such conditions.Presented at the Eighth International Congress of Biometeorology, 9–14 September 1979, Shefayim, Israel.