Assessment of temporal changes in pulmonary edema with NMR imaging

Nuclear magnetic resonance imaging (NMRI) parameters [longitudinal relaxation time (T1), transverse relaxation time (T2), and signal intensity] acquired at a magnetic field of 2.35 T were validated with a study of nine different phantom gel solutions. This technique was then applied to study 13 anesthetized supine cats, among which 10 had lung edema induced by oleic acid (0.075 ml/kg); the result was compared with postmortem analyses of lung water. Three animals (series A) were imaged until the edema was first visualized in NMRI, usually 15-20 min after oleic acid infusion. Another seven animals (series B) were imaged over 4-5 h. As lung water increased, so did the signal intensity. When edema first appeared, T1, T2, and the volume of the edematous region within the slice in the upper lobes showed no gravity-dependent differences; this was confirmed by postmortem measurements (series A) of lung water. With time, gravity-dependent regions displayed greater volumes of edematous regions and greater T1 values (P less than 0.01), suggesting a continued accumulation of lung water. In comparison, nondependent regions displayed constant volumes of edematous region and lesser T1 values (P less than 0.01), suggesting an increased protein concentration but no change in lung water. This study suggests the potential applicability of NMRI parameters in the assessment of pulmonary edema.     

Trace elements in scalp hair of professional drivers and university teachers in Hong Kong

Hair samples of 23 male professional drivers and 20 male university teachers in Hong Kong were collected, and the concentrations of Al, Sb, As, Ca, Cu, Fe, Pb, Mg, Mn, Hg, K, Sr, S, V, and Zn were measured. Both of the target groups fell within the same age group of 35–45. The washing method of using detergent and powder was found to be comparable to that of using ether. Difference in the mean concentration of each detected element in the two groups was tested by the Student'st-test and the Wilcoxon rank-sums test. Hair concentrations of Al, Sb, Pb, Mg, Mn, and K in the «Driver Group» were significantly (p<0.05) higher than those in the “Teacher Group.” On the other hand, As and Hg were found to have a higher concentration in hair of teachers. Interpretation of the findings in terms of the environmental factor and the metabolic rate was attempted.     

Chemical induction of adventitious root formation in Taxus baccata cuttings

The effect of some auxins (IBA and NAA), phenolic compounds (phloroglucinol, gentisic acid and coumarin), a combination of auxins and phenolics, and a systemic fungicide (Bavistin) have been examined for stimulatory effects on adventitious root formation in stem cuttings (current season's growth) of Taxus baccata L. In general lower concentration (0.25 mM) of both IBA and NAA was more effective in inducing rooting of cuttings taken from both male and female trees. The combined treatment of IBA+NAA (0.25 mM each) showed some success in cuttings from male trees only (55%, compared to 15% rooting in cuttings from female trees). Generally, the callus formation was quite high (70%) in all auxin treatments (alone or in combination). Among the phenolics, 40% rooting success was achieved with phloroglucinol only, while coumarin and gentisic acid were ineffective. The combined treatment of auxins and phenolics also failed to promote rooting. On the other hand, Bavistin was extremely effective for callusing (90%) as well as rooting (80%). The effectiveness of various compounds tested for rooting of young stem cuttings declined in the order: 0.25 mM IBA>0.05% Bavistin>0.25 mM NAA>1.25 mM IBA>15 mM phloroglucinol>IBA+NAA (0.25 mM each). In addition to the auxins, IBA and NAA that are widely used for commercial propagation, the auxin-like properties of the fungicide Bavistin could be exploited for adventitious rooting in T. baccata, and in other plant species.     

Halide permeation through three types of epithelial anion channels after reconstitution into giant liposomes

Anion-selective channels from apical membranes of cultured CFPAC-1 cells were isolated and incorporated into giant liposomes for patch clamp recording. Liposomes were formed from L--lecithin by a dehydration-hydration method. Ion channels were characterized using the excised inside-out patch clamp configuration. The most commonly observed anion channels were similar to those observed in native epithelial tissues. The linear 20 pS Cl channel had the halide permeability sequence Cl^– > I^– Br^– > F^–, and showed anomalous mole-fraction behavior in solutions containing different proportions of Cl^– and F^–, ions. The autwardly rectifying Cl^– channel had the halide permeability sequence I^– > Br^– > Cl^– > F^–, and also showed anomalous molefraction behavior, indicating that both these channels probably contain multi-ion pores. The third, voltage-dependent anion channel showed at least five different substrates, had a conductance of 390 pS in the main state, and showed two types of kinetics, fast (openings and closings < 1 ms), and slow (openings and closings > 1 s). The channel was seen more frequently after reconstitution into giant liposomes than in intact cells. It was not selective amongst the halides, and there was no deviation from a linear dependence of relative current on molar fractions, indicating relatively simple permeation through the pore. Differences in halide permeabilities suggest that different anion channels may be related to different membrane proteins. Comparison with the chloride channel proteins isolated biochemically from epithelial cell membranes is discussed. Correspondence to: M. Duszyk     

自由飞行蜜蜂对静止目标形状和颜色的综合识别能力

研究了蜜蜂对相同颜色和不同颜色目标图对的形状以及颜色的综合识别能力实验过程中,蜜蜂始终处于自由飞行状态.做为刺激目标使用的图对分别有相同颜色不同几何形状、相同颜色不同拓扑结构和不同颜色几何形状三组.主要结果有三点:(1)在相同颜色的条件下,蜜蜂可以分辨出图形的几何形状,并且识别能力与图对的相似程度成反比(2)在刺激图形为环形时,蜜蜂对图形平均亮度敏感;在平均亮度相同的情况下,对环形细节变和尺寸大小不敏感.(3)在不同颜色不同几何形状的刺激条件下.蜜蜂视觉信息加工过程中颜色因素会抑制几何形状因素而起主要作用.这三个结果可以视为深入研究颜色加工通道和几何形状加工通道之间内在关系的基础.     

模拟四季温度层积对南方红豆杉种子生理性状的影响

为了解濒危物种南方红豆杉(Taxus chinensis var. mairei)种子内含物含量受温度和湿度层积的影响,设置4个季节、2种湿度(16%和24%)基质层积处理,对种子的可溶性糖、淀粉、可溶性蛋白和脂肪等内含物质的变化进行研究。结果表明,不同层积处理下种子贮藏物质的含量有显著变化,春季层积9个月后,可溶性蛋白含量达到最高值;可溶性糖含量呈现降低-升高-降低的变化趋势;淀粉和脂肪含量均随层积逐渐减少。秋季层积9个月后,淀粉含量降至最低。相比于24%湿度,16%湿度的春季、秋季、冬季层积9个月后,脂肪含量均减少较多,说明16%湿度下种子代谢活动更强。春季和秋季的暖温更能促进种子代谢,促进种子形态后熟。夏季温度过高,导致种子生活力下降,夏季层积处理3个月后,种子已经发霉和腐烂。层积过程中,种子内含物在相关酶的作用下,降解为可溶性蛋白、可溶性糖等,为种子萌发提供物质与能量。种子层积时间、温度和湿度及交互作用可作为种子内含物的调控因子。     

Critical roles of non-coding RNAs in lifecycle and biology of Marek’s disease herpesvirus

Science China Life Sciences - Over the past two decades, numerous non-coding RNAs (ncRNAs) have been identified in different biological systems including virology, especially in large DNA viruses...     

Effect of phenolic compounds on abscisic acid-induced stomatal movement: Structure – activity relationship

Application of abscisic acid (ABA) brings about stomatal closure within 30 min in epidermal peels of Vicia faba . A number of phenolic compounds antagonise the effect of ABA. Derivatives of benzoic acid, cinnamic acid, coumarin and flavonoids have been studied in order to establish structure – activity relationship. Derivatives of benzoic acid reverse the ABA effects. Coumarin, esculetin and three hydro derivatives of cinnamic acid fail to show the anti-ABA activity. Thus, the presence of parahydroxyl group and double bond in the side chain is necessary for anti-ABA activity.     

日粮水平对鲇鱼日总代谢,特殊动力作用和活动代谢的影响

在２５℃不同日粮水平（饥饿─４％体重／ｄ）条件下,采用封闭式呼吸仪测定了３１尾鲇鱼（体重７２．９─１３３．３ｇ）的日总代谢率,然后,将鱼限制在呼吸室中的限动笼内测定了其中２０尾鲇鱼的静止日总代谢率,并计算出了鲇鱼的特殊动力作用（ＳＤＡ）和活动代谢率。日总代谢率和活动代谢率都随日粮水平的升高呈“Ｖ”形变化,分别在约１％和２％体重／ｄ的日粮水平时最低,ＳＤＡ的能量支出占摄入能量的２２．１４％。