The effect of SAN 9789 and light on the germination of seeds from Taraxacum vulgare

Photoblastic seeds (achenes) of Taraxacum vulgare coll. were treated with a water solution of SAN 9789, 4-chloro-5 (methylamino) -2- (α,α,α-trifluoro- m -tolyl) -3(2H) pyridazinone. SAN-treatment increased the germination in darkness from 0 to 12%. An irradiation for 5 min with red light, giving a germination of 12% for seeds in water only, gave together with SAN treatment a germination of 60%. In both water and SAN, the effect of red irradiation could be reversed by a short irradiation (15 min) of far-red light. If far-red light was repeatedly given (5 min per h) it had hardly any effect on germination in water (4% germination), but for seeds in SAN solution, intermittent far-red light had a stimulating effect (63% germination). If far-red light was given continuously for 96 h, the germination in water was 1% and in SAN solution 17%. The results in the present paper indicate that SAN may broaden the concentration interval of P_fr for which germination is high.     

A review of amyloid staining: methods and artifacts

Abstract

Amyloid detection is very precise at this time, because several methods are available to the pathologist. Awareness of potential nonspecific staining, possible pitfalls and methods for improving the detection process are basic to enhancing the staining of amyloid and interpreting this staining. The role of the pathologist has progressed through history from the basic detection of amyloid as a substance to immunophenotypical classification of the particular amyloid present.     

Demographic Variability in Monkeys: Implications for Theory and Conservation

Demographic parameters of nonhuman primates, like those of all other organisms, vary over time and space. However, many contemporary models comparing multiple species treat these parameters as if they were static. Population density, group size, age-sex composition, natality, and juvenile recruitment all vary considerably within populations that researchers have studied for many years. It is important to describe and to understand the variance not only for the development of more realistic models but also to clarify the status and trends of the populations in order to develop effective conservation management plans. A critical issue is to distinguish real demographic trends from the natural demographic variation that occurs both between sites and within specific sites over time. With few exceptions, demographic data for most nonhuman primates are not amenable to life-table analyses because observation conditions typically prevent collection of the data required and generation time is long. Instead, one must evaluate demographic indices that serve as surrogates for more detailed and accurate data, such as that derived from life-time observations of recognizable individuals of known parentage. Long-term monitoring is essential to understand the extent of and trends in demographic variation. These points are exemplified with case studies from vervets, red howlers, and red colobus as they relate to the likely causal factors of habitat quality, disease, predator-prey imbalance, population compression, and intragroup competition for food.     

Red clothing increases perceived dominance,aggression and anger

The presence and intensity of red coloration correlate with male dominance and testosterone in a variety of animal species, and even artificial red stimuli can influence dominance interactions. In humans, red stimuli are perceived as more threatening and dominant than other colours, and wearing red increases the probability of winning sporting contests. We investigated whether red clothing biases the perception of aggression and dominance outside of competitive settings, and whether red influences decoding of emotional expressions. Participants rated digitally manipulated images of men for aggression and dominance and categorized the emotional state of these stimuli. Men were rated as more aggressive and more dominant when presented in red than when presented in either blue or grey. The effect on perceived aggression was found for male and female raters, but only male raters were sensitive to red as a signal of dominance. In a categorization test, images were significantly more often categorized as ‘angry’ when presented in the red condition, demonstrating that colour stimuli affect perceptions of emotions. This suggests that the colour red may be a cue used to predict propensity for dominance and aggression in human males.     

Primates: Models for red cell transfusion studies—Cryopreservation and survival of transfused red cells in primates

Primates are excellent models for study of blood transfusion in humans. Erythrocytes of chimpanzees, gibbons, baboons, and rhesus monkeys have a half life (T/2) of 14 to 16 days and a life span (T/10) of approximately 50 to 60 days, which is about half of that found in man. Red cells of primates were cryopreserved by freezing using either a droplet method or the low-glycerol rapid-freeze procedure. Thawed cells survive normally when transfused into the same species. Transfusion of incompatible isologous blood in alloimmunized baboons, in the presence of high titer antibodies, showed survival with small volumes to be virtually nil, but with large volumes, a short normal survival period was followed by a “collapse” phenomenon similar to that seen in humans.     

红细胞伪装纳米颗粒:一个具有潜力的药物及疫苗递送系统

红细胞伪装纳米颗粒是一种以红细胞或红细胞膜纳米囊泡为载体在体内递送药物、酶、多肽和抗原等物质的系统,具有生物相容性好、循环周期长、靶向性强等优势。本文从红细胞载体的种类、发展历程、递送策略应用以及其局限性和未来的挑战等方面进行了详细阐述,并展望了其未来的发展方向。     

Calcium-induced proteolysis of spectrin and band 3 protein in rat erythrocyte membranes

Calcium-dependent protease activity capable of degrading a number of endogenous proteins was found in rat red blood cell membranes. This protease activity, like that found in human red blood cells, was activated by low concentrations of calcium, but in the rat red blood cells, unlike the human red blood cells, calcium-activated protease activity was membrane-bound. A number of endogenous membrane-bound proteins were degraded after the addition of calcium to the membranes. These included spectrin bands 1 and 2 as well as bands 3, 2.1, and 2.2. No calcium-induced aggregation (transglutaminase activity) was noted in the rat red blood cell membranes.     

Sodium and potassium interactions with Na+-ATPase of inside-out membrane vesicles from high-K+ and low-K+ sheep red cells

Na⁺-ATPase of high-K⁺ and low-K⁺ sheep red cells was examined with respect to the sidedness of Na⁺ and K⁺ effects, using inside-out membrane vesicles and very low ATP concentrations (?2 μM). With varying amounts of Na⁺ in the medium, i.e., at the cytoplasmic surface, Na_cyt⁺, the activation curves show that high-K⁺ Na⁺-ATPase has a higher affinity for Na_cyt⁺ compared to low-K⁺. The apparent affinity for Na_cyt⁺ is also increased by increasing the ATP concentrations in high-K⁺ but not low-K⁺. With Na_cyt⁺ present, Na⁺-ATPase is stimulated by intravesicular Na⁺, i.e., Na⁺ at the originally external surface, Na_ext⁺, to a greater extent in low-K⁺ than high-K⁺. Intravesicular K⁺ (K_ext⁺) activates Na⁺-ATPase in high-K⁺ but not in low-K⁺ vesicles and extravesicular K⁺ (K_cyt⁺) inhibits low-K⁺ but not high-K⁺ Na⁺-ATPase. Thus, the genetic difference between high-K⁺ and low-K⁺ is expressed as differences in apparent affinities for both Na⁺ and K⁺ and these differences are evident at both cytoplasmic and external membrane surfaces.     

红穗醋栗色素理化性质的研究

本试验研究了红穗醋栗色素的理化性质,结果表明:红穗醋栗色素热稳定性很好,而光照对其有一定的降解作用。pH值对该色素影响明显,宜在酸性食品中应用。几种金属离子Na~ 、Ca~(2 )、Al~(3 )、Zn~(2 )。Cu~(2 )对该色素的色泽没有影响;而Fe~(3 )、Sn~(2 )则有不良影响。食品中常含的几种添加物葡萄糖、蔗糖、淀粉和抗坏血酸对该色素无不良影响。红穗醋栗色素对Na_2SO_3的还原性耐性较强,对H_2O_2的耐氧化性很差。防腐剂苯甲酸钠对该色素也有一定的不良影响。     

光质对杉木种子萌发及幼苗生长的影响

光是影响森林早期天然更新(种子萌发和幼苗生长)的重要因子之一.但光质对杉木(Cunninghamia lanceolata(Lamb.) Hook)早期更新的影响尚不清楚.为探讨光质对杉木种子萌发及幼苗生长的影响机制,以杉木种子为研究对象,通过设置8h白光(W)、8h红光(R)、6h红光-2 h远红光(R-FR)、4h红光-2 h远红光-2 h红光(R-FR-R)、黑暗(D,对照)5种不同光质处理,观察种子萌发及幼苗生长特征.结果表明,不同光质处理对杉木种子萌发影响显著,D和R-FR-R处理促进杉木种子萌发,R处理抑制种子萌发.最后一次照光选择红光处理(R和R-FR-R)能够显著促进杉木幼苗根和子叶的伸长,促进生物量积累以及增加叶生物量分配比例,但抑制茎的伸长,远红光处理则促进茎的生长.杉木种子为光不敏感种子,黑暗处理下萌发率最高,且远红光间断处理能够相对促进其萌发,说明杉木种子可以较好地适应异质光环境.     

Importance of cholesterol-phospholipid interaction in determining dynamics of normal and abetalipoproteinemia red blood cell membrane

Acanthocytic red blood cells in patients with abetalipoproteinemia have a decreased membrane fluidity that is associated with increased sphingomyelin/phosphatidylcholine (SM/PC)§ ratios. Here we describe studies designed to gain better insight into (i) the interrelationship between the composition of lipoprotein and red blood cell membrane in abetalipo-proteinemia patients and normal controls; and (ii) how the differences in lipid composition of the red blood cell membrane affect its fluidity. The increased SM/PC ratio found in abetalipoproteinemia plasma high density lipoproteins (HDL) (3 times greater than controls) was paralleled by an increase in this ratio in acanthocytic red cells, but to a lesser degree (almost twice greater than control red cells). Cholesterol/phospholipid mole ratios (C/P) were increased 3-fold in abetalipoproteinemia HDL, but only slightly increased in red cells compared to controls values. As in the controls, 80–85% of abetalipo-proteinemia red cell sphingomyelin was found to be in the outer half of the erythrocyte membrane. Membrane fluidity was defined in terms of microviscosity ({ie116-1}) between 5 and 42°C by the fluorescent polarization of 1,6-diphenylhexatriene (DPH) present in erythrocyte ghost membranes. At all temperatures, membrane microviscosity was higher in abetalipoproteinemia ghosts than controls, but these differences decreased at higher temperatures (12.34 vs 9.79 poise, respectively, at 10°C; 4.63 vs 4.04 poise at 37°C). These differences were eliminated after oxidation of all membrane cholesterol to cholest-4-en-3-one by incubation with cholesterol oxidase. Following cholesterol oxidation, the membrane microviscosity decreased in patient ghosts more than in normal red blood cells so that at all temperatures no significant differences were present relative to control ghosts, in which the apparent microviscosity was also diminished but to a lesser degree. Therefore, although increased SM/PC ratios in abetalipoproteinemia may be responsible for decreased erythrocyte membrane fluidity, these effects are dependent upon normal interactions of cholesterol with red cell phospholipid.     

Even patients with mild COVID‐19 symptoms after SARS‐CoV‐2 infection show prolonged altered red blood cell morphology and rheological parameters

Infection with the novel severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) and the associated coronavirus disease‐19 (COVID‐19) might affect red blood cells (RBC); possibly altering oxygen supply. However, investigations of cell morphology and RBC rheological parameters during a mild disease course are lacking and thus, the aim of the study. Fifty individuals with mild COVID‐19 disease process were tested after the acute phase of SARS‐CoV‐2 infection (37males/13 females), and the data were compared to n = 42 healthy controls (30 males/12 females). Analysis of venous blood samples, taken at rest, revealed a higher percentage of permanently elongated RBC and membrane extensions in COVID‐19 patients. Haematological parameters and haemoglobin concentration, MCH and MCV in particular, were highly altered in COVID‐19. RBC deformability and deformability under an osmotic gradient were significantly reduced in COVID‐19 patients. Higher RBC‐NOS activation was not capable to at least in part counteract these reductions. Impaired RBC deformability might also be related to morphological changes and/or increased oxidative state. RBC aggregation index remained unaffected. However, higher shear rates were necessary to balance the aggregation‐disaggregation in COVID‐19 patients which might be, among others, related to morphological changes. The data suggest prolonged modifications of the RBC system even during a mild COVID‐19 disease course.     

The effects of SAN 9789 and light on phytochrome and the germination of lettuce seeds

Photoblastic seeds (akenes) of lettuce (Lactuca sativa (L.) cv. Grand Rapids) were treated with SAN 9789 [4-chloro-5-(methylamine)-2-a, a, a,-trifluoro-m-tolyl-3-(2H)-pyridasinone]. The seeds weere placed in Petri dishes on filter paper soaked with water or SAN solution. The treatment increased the germination in darkness from 17% for water to 78% for SAN treated seeds. An irradiation with 5 min red light gave a germination of 98% both in water and in SAN. In water the effect of red irradiation could be reversed with a short irradiation (8 min) of far red light (17% germination), while in SAN solution the far red reversibility was poor (92% germination). If the far red light was given repeatedly (5 min per h) it had a slightly larger effect. If given continuously for 24 hours, the germination in water was decreased to 0.3% and in SAN solution to 9%. Possible mechanisms for the SAN effect are discussed.     

Effects of Dietary Fish Oil on Polyunsaturated Fatty Acid Desaturation in Fetal and Postnatal Rats

The effects were determined of dietary fish oil on the polyunsaturated fatty acid desaturation in rats fed on fish oil-containing diets (FS group) and on non-fish oil diets (CN group) during the fetal to postnatal periods. Although the desaturase activity in the liver microsomes of the FS group was higher than that of the CN group before birth, this was not altered by dietary fish oil after birth. However, a lower 20:4n-6 concentration before and after birth, and lower linoleic acid desaturation index ((dihomo-γ-linolenic acid + arachidonic acid)/linoleic acid)) at 10 wk of age in the FS group than in the CN group were observed in the liver microsomal phospholipids. The Δ6-desaturase activity in the brain microsomes of the FS group was lower than that of the CN group. These findings suggest that an intake of dietary fish oil by dams and postnatal rats affected the arachidonic acid concentration due to the decreased desaturase activity in the rats’ microsomes.     

光质对东北次生林生态系统主要树种种子萌发的影响

以东北次生林生态系统5个主要树种（日本落叶松、黄檗、色木槭、水曲柳和红松）种子为对象,采取室内控制(5个主要树种)和野外模拟(红松和日本落叶松)相结合的方法,研究光质对种子萌发的影响.室内和实际林分下分别设置了4种不同光质类型处理（以黑暗为对照）和3个红光/远红光比值(R/FR)梯度.结果表明： 不同光质类型除对日本落叶松种子萌发的影响不显著外,对其他4个树种种子萌发影响均显著.其中,黄檗种子萌发率在白光下达到最高,色木槭、水曲柳和红松种子萌发率在红光-远红光-红光照射下达到最高.林分内试验结果与室内一致,红松种子萌发率随林内R/FR下降而明显下降,落叶松种子萌发则不受光质的影响.在自然林分条件下,R/FR随着光斑活动不断变化,色木槭、水曲柳和红松种子萌发格局可能是对森林光斑环境适应的结果.大粒种子萌发显著受光质的影响.     

亚热带典型常绿阔叶树种叶片叶绿素含量与其高光谱特征间的关系

叶绿素在植物的生理生态过程中非常重要.利用高光谱数据,揭示光谱反射率上特征光谱与叶绿素含量间的关系将有助于理解叶绿素光谱反射特征的规律.选取了6种亚热带常绿阔叶树种,抽取一定数量的叶片样品,分别测量了叶片的光谱反射率及其叶绿素含量,并建立了光谱反射率曲线上的红边位置附近的光谱反射率和叶绿素总量间的回归模型.结果显示:对所研究的树种而言,红边位置处一窄波长范围内的平均光谱反射率与叶绿素总量间的相关性普遍较高,回归效果显著.从高光谱遥感的角度结合植物的生理生态特点分析了其机理.建立的有关红边位置处的光谱反射率与叶绿素总量间的回归模型普遍具有较高的拟合度,其应用前景较好.     

辣椒红色素的研究与应用

辣椒红色素是红辣椒果实中的四萜类天然色素,着色效果好、安全性高,广泛应用于食品、药品、化妆品和饲料工业.概述了辣椒红色素的理化性质及其在辣椒果实成熟过程的动态变化,阐述了辣椒红色素的提取方法和在各领域应用,并展示了其广阔的应用前景.     

Photophysical and structural aspects of perylene‐doped 2‐naphthol luminophors: Green emission by exciplex formation

Several perylene (Pery)‐doped 2‐naphthol (2‐NP) (Pery/2‐NP) luminophors were prepared using conventional solid‐state reaction techniques. Energy transfer in the excited state was examined using fluorescence spectroscopy and cyclic voltammetry. Fluorescence studies revealed exciplex formation by Pery in the form of structureless and broad spectra at higher concentrations with monomer quenching of 2‐NP; a broad green emission was observed in the range 500–650 nm, peaking at 575 nm. Structural properties and thermal stability were analyzed using X‐ray diffraction, scanning electron microscopy and TGA‐differential scanning calorimetry. Highest occupied molecular orbital and lowest unoccupied molecular orbital energy levels were observed in the range 5.56–5.61 eV and 2.79–2.81 eV, respectively with a 2.77–2.82 eV band gap. The present study reveals these to be probable candidates for hole‐transporting materials suitable in optoelectronics.