Study on a Mutant with Low Content Chlorophyll b in a High Yielding Rice and Its Photosynthesis Properties

A high yielding rice mutant ( Oryza sativa L. cv. Zhenhui 249) with low chlorophyll b was recently discovered in the field. The mutant was mainly characterized by the decrease of the content of extrinsic antennae complex. This variation was shown in the stage when the leaves were expanding. When the leaves are at the final developmental stage, the content would approach to that of the wild type. It was discovered that only moderate amount of chlorophyll b decreased in this mutant. The photosynthetic apparatus of the mutant was rather stable in the whole life span of the leaf. The extrinsic antennae complex of the mutant might make efficient use of light and meanwhile reduce the production of O -· 2.

Anti-ultraviolet aging tests of asphalts adapting to environment in Tibetan Plateau of China

Ultraviolet （UV） aging is one of the main factors which cause premature damage of asphalt pavements in the Tibetan Plateau, China. According to the measured levels of UV radiation, aging tests of styrene-butadiene rubber （SBR） asphalts with different contents of three anti-UV-aging agents including nano-TiO2, CeO2 and carbon black are performed. Common indices, which include retained penetration after thin film oven tests （TFOT） and softening point, and strategic highway research program （SHRP） indices of aged asphalts are evaluated. Infrared absorption spectral analysis is performed on asphalt specimens with 0. 8% carbon black which have been aged for different aging times （500, 1000 and 1 500 h）. By grey incidence analysis, the optimal contents of anti-UV-aging agents are determined. The results show that TiO2 and CeO2 are not only good UV absorbing or shielding agents, but also strong oxidants. Carbon black is a good anti-UV-aging agent, and its optimal content is about 0. 8% of asphalt weight. UV aging of asphalt mainly occurs in the early stages of aging. The longer the aging time, the more severe the aging of asphalt.

Photoperiod Control of Apical Bud and Leaf Senescence in Pumpkin ( Cucurbita pepo ) Strain 185

Short_day (SD) induced the plant senescence in pumpkin ( Cucurbita pepo Linn.) strain 185. Structural assay, gene expression and a series of biochemical analyses were performed to analyze the senescence mechanism in pumpkin strain 185 exposed to SD. Two aspects of important changes initiated in SD exposure contributed to the senescence process. SD functionally led to the initiation of the apical transformation from vegetative to reproductive growth, and then programmed cell death (PCD) in the apical meristem, causing the loss of vigorous growth activity. Moreover, SD treatment resulted in the formation of a great number of dying cells in mesophyll tissue later in the development compared with the phenotype of plants under long_day (LD) conditions. During the senescence process, high expression of nuclease is an important molecular event. These results indicate that the initiation of senescence process in pumpkin stain 185 plants is closely related to the death of cells in apical meristem and mesophyll.

“峨联”散记

“峨联”散记●傅正深“峨联”，它的全称是“峨眉戏剧创作联谊会”；是以成、渝两地的十二个地、市文化局创作办公室联合起来研究戏剧创作的半官方组织。由各地、市文化局轮流作东、实行执行主席和秘书长负责制。何以“峨眉”命名？峨眉山饮誉中、外，且在“峨联”的版图...

Determination the Vigor of Rice Seed with Different Degrees of Aging with Ultraweak Chemiluminescence During Early Imbibition

用高灵敏度的单光子计数系统探测人工老化 (40℃ ,相对湿度 90 % ) 0、7、14和 2 1d的水稻种子吸胀初期的超弱化学发光强度变化 ,首次观测到水稻 (OryzasativaL .)种子吸胀初期超弱化学发光强度与其老化程度有关。加水激活水稻种子的超弱化学发光 ,其强度依赖于种子的老化程度。实验结果表明水稻种子的人工老化时间越短 ,则吸胀初期 (2 0～ 30min)超弱化学发光的强度越强 ,萌发率越高。水稻种子萌发率与超弱化学发光强度呈显著正相关。观测水稻种子吸胀初期超弱化学发光强度的变化可望成为检测种子老化程度的一种快速、简便、无损伤的新方法。

坚持做热敷 眼睛不老花

我今年80岁，50岁开始戴150度老花镜，不到几年上升到250度，不管办什么事，老把眼镜带上，看报、写字更是不可少。

人老眼不“老”

眼睛是心灵的窗户,其重要性不言而喻。人到老年,眼睛就会有些生理变化,首先的改变是眼的调节功能降低。根据眼科专家的统计,10岁的小孩调节功能是10屈光度,40岁时下降为3.5屈光度,到了65岁,其调节力为零。人既能看远又能看近,就是依靠眼的调节功能。调节功能降低到一定程度,阅读就会发生困难,45岁后眼的调节力就满足不了阅读写字的要求,也就是出现了“老花”现象。没有人能背离这个规律。

“大猪倌”心系电气化

“大猪倌”心系电气化一九九六年五月三十日黄昏，江苏省启东市惠丰乡庙角村第九村民组九十高龄的曹庭荣老人戴上了老光眼镜，在灯火通明的孙儿家里打开电视机，一瞧清晰的荧屏—听着那悦耳的歌曲，、心花怒放，他拉着孙子曹、水飞的手半开玩笑地说＊、水飞，你这个大猪倌...

税干“老哈哈”

税干“老哈哈”●吴彩生“老哈哈”姓汪，名祥林，头发花白，戴一付深度老光眼镜，是霍山县国税局诸佛庵征收分局的票管员，他虽然年龄老了一点，但工作热情没有“老”。整天都是乐哈哈的，同志们都戏称他为“老哈哈”。“老哈哈”几十年如一日，兢兢业业，一心一意地为纳...

The protective effect of Dendrobium officinale polysaccharides on photoaging fibroblasts by scavenging reactive oxygen species and promoting the expression of TGF-β1

The purpose of this study was to explore the protective effect of Dendrobium officinale polysaccharides （DOP） onphotoaging human skin fibroblasts and its specific mechanism of action. The photoaging fibroblast model wasestablished by ultraviolet B （UVB） irradiation. The toxic effects of different concentrations of DOP were detected usingMTT. Senescent cells were detected using a β-galactosidase kit. Reactive oxygen species （ROS） in cells were detectedusing a flow cytometer. The expression of matrix metalloproteinase-1 （MMP-1）, type I collagen C-terminal peptide（CICP）, and transforming growth factor β-1 （TGF-β1） in spent culture medium was detected by ELISA. The resultsshowed that the low concentration of DOP （20, 40, 80 μg/mL） had no cytotoxicity on fibroblasts. After 60 mJ/cm2UVBirradiation, the number of aging β-gal-positive cells increased, the levels of CICP and TGF-β1 in spent culture mediumdecreased, while the levels of MMP-1 and ROS increased. After administration of DOP on photoaging fibroblasts, thenumber of aging β-gal-positive cells decreased, the levels of ROS and MMP-1 decreased, and the levels of TGF-β1 andCICP increased. This experiment suggests that DOP has the effect of removing ROS induced by UVB, regulating thebalance of collagen production and degradation, and protecting photoaging human skin fibroblasts.

Study on the neurotoxic effects of low-level lead exposure in rats

Objective: To investigate effects of developmental lead exposure on nitric oxide synthase (NOS) activity in different brain regions and on N-methyl-D-aspartate (NMDA) receptor mRNA expression in the hippocampus of rats. On the basis of these observations, we explored possible mechanisms by which lead exposure leads to impaired learning and memorizing abilities in children. Methods: A series of rat animal models exposed to low levels of lead during the developing period was established (drinking water containing 0.025%, 0.05% and 0.075% lead acetate). NOS activities in the hippocampus, the cerebral cortex, the cerebellum and the brain stem were determined with fluorescence measurement and levels of mRNA expression of the NMDA receptor 2A (NR2A) subunit and NMDA receptor 2B (NR2B) subunit in the rat hippocampus were measured with Retro-translation (RT-PCR). Results: There were no differences in the body weight of rat pups between any of the groups at any given time (P>0.05). The blood lead level of Pb-exposed rat pups showed a systematic pattern of change: at 14 d of age, it was lower than that at 7 d of age, then rising to the peak level at 21 d and finally falling to lower levels at 28 d. The hippocampal NOS activities of lead-exposed groups were all lower than that of the control group on the 21 st and 28th day (P<0.01). NOS activities in the cerebellum of lead-exposed groups were all lower than that of the control group on the 21 st and 28th day (P<0.001) and the NOS activity of the 0.025% group was significantly lower than that of the 0.05% and 0.075% groups on the 28th day (P<0.05).NOS activity in the cerebral cortex of the 0.075% group was significantly lower than that of the control, 0.025% and 0.05% groups on the four day spans (P<0.001). There was no significant difference of NOS activity in the brain stem between any lead-exposed group and the control group on the four day spans. In the 0.05% and the 0.075% groups, the level of NR2A mRNA expression was higher than that in the control group at 7 d and 14 d of age (P<0.05). In the 0.025% group, the level of NR2A was found to be higher than that in the control group at 7 d of age only (P<0.05). No significant differences were found for the levels of NR2B mRNA expression between any of the groups at any given time. Conclusions: NOS activity in the hippocampus, the cerebral cortex and the cerebellum are inhibited by lead exposure. The degree of the inhibitory effect depends on the time span of exposure and the lead concentration. Developmental low-level lead exposure was found to raise the level of NR2A mRNA expression in the hippocampus of rats. Developmental low-level lead exposure does not affect the level of NR2B mRNA expression in the hippocampus.

Effects of polypeptide from Chlamys farreri on amino acid con-tent in guinea pig skin irradiated by chronic ultraviolet A and B

We examined the effects of polypeptide from Chlamys farreri (PCF) on the amount of hy-droxyproline in guinea pig skin irradiated by chronic ultraviolet A (UVA) and ultraviolet B (UVB) radiation. PCF was applied locally before repeated exposure of guinea pig to UVA and UVB. The contents of hy-droxyproline and other amino acids in guinea pig skin were determined by automatic amino acid analyzer. Our results showed that: (1) long-time UVA and UVB radiation can reduce dramatically the amounts of hy-droxyproline, aspartic acid, threonine, glycine, phenylalanine and lysine in guinea pig skin in comparison with the control group (P < 0.05); (2) Compared with model group, pre-treatment with 5 % and 20 % PCF prior to UVA and UVB radiation can inhibit the decline of amino acids content in guinea pig skin in a dose-dependent manner (P < 0.05). As the decrease of hydroxyproline, glycine and lysine contents in the skin directly reflexes type I collagen degeneration, our results indicated that the chronic application of PCF can protect skin type I collagen against UV radiation, and thus protect skin from photoaging.

Expression Level of a Transcription Factor Gene Mdhd-Zip Up-regulated during Apple Fruit Senescence

[Objective] This study aimed to explore the role of one apple transcription factor of homeodomain-leucine zipper(MdHD-Zip) during apple fruit senescence.[Method] Postharvest Red Fuji fruits(Malus domestica Borkh ‘Red Fuji') were stored at room temperature(18 ℃-20 ℃) and cold condition(0 ± 1 ℃) separately.Fruit firmness and ethylene production during storage process were analyzed.Transcript level of Md HD-Zip was detected by real-time quantitative PCR during apple fruit storage under room temperature and cold condition.[Result] Expression level of Md HD-Zip was found up-regulated in later stage of apple fruit senescence at room temperature,while it showed a peak level after one month of cold storage.[Conclusion] The results of the present study suggest that Md HD-Zip may play a role in regulating apple fruit senescence.

Relationship of Ultraweak Luminescence Intensity with Physiological Metabolism of Maize Seeds during Artificial Aging

The seeds of maize （Zea mays L.） variety Zhengdan 958 were used to study the change of ultraweak luminescence （UWL） intensity and its relationship with seed vigor, relative electric conductivity and ATP content during artificial aging. The results indicated that the germination percentage, germination potential, germination index, UWL intensity and ATP content decreased gradually, while the relative electric conductivity increased with the prolongation of artificial aging. The correlation analysis showed that UWL intensity was significantly positively correlated with ger- mination percentage, germination potential, germination index and ATP content, while significantly negatively correlated with relative electric conductivity. It was concluded that UWL was closely related to the energy level symbolized by ATP content, and as a fast nondestructive physical indicator with better sensitivity, it could be applied into the study of seed vigor nondestructive testing.

Analysis of Application of Mean Glandular Dose and Factors on Which It Depends to Patients Aged 65 to 80

Every year there are new 1,600 cases of breast cancer in Bosnia and Herzegovina. The most effective method for early detection of breast cancer is mammography. To examine risks and benefits of this diagnostic method it is necessary to determine patient doses. Mainly, almost all published data about patient doses refer to two specific age groups： 40-49 and 50-64 years of age. Very little data about patient doses applied during a routine mammography for patients from 65-80 years of age are available. During the conducted research, one calculated doses for the complete mammographic examination of 42 patients from this age group. The calculated patient doses are related to the whole spectrum of technical, physical, clinical and diagnostic parameters which compose a complete mammographic examination.

Photosynthetic Excitation Pressure Causes Violaxanthin De-epoxidation in Aging Cabbage （Brassica Oleracea L.） Leaves

The purpose of the present studies was analysis of the age induced changes in photochemical efficiency and xanthophyils cycle pigments of the primary cabbage （Brassica oleracea L. cv. Capitata f. alba） leaves. Photochemical efficiency of photosystem Ⅱ （PS Ⅱ） was studied by a pulse amplitude modulated chlorophyll fluorescence apparatus, chlorophyll concentration was analysis spectrophotometrically and xanthophyll cycle pigments were estimated by high-pressure liquid chromatography （HPLC）. Leaf senescence was accompanied with a decrease both in chlorophylls concentration, the photochemical efficiency and rate constant for PS Ⅱ photochemistry whereas non-photochemical parameters increased. Excitation pressure （1-qP） which is a measure of relative lumen acidification increased by 1.2x in aging leaves. The maximum quantum yield of PS Ⅱ showed no significant change. The level of de-epoxidised xanthophylls increased but the concentration of mono- and di-epoxy xanthophylls decreased in aging leaves. A linear relationship between the excitation pressure and the depoxidation state of the xanthophyll cycle pigments and lutein, during the onset of senescence suggests that excitation pressure can be used as a sensor for monitoring the onset of senescence as well for the de-epoxidation state of the xanthophylls responsible for non-photochemical quenching in stressed leaves.

Evaluation of rutting and low-temperature cracking resistancesof warm-mix recycled asphalt bindersunder the secondary aging condition

The rutting and low-temperature resistances of warm-mix recycled asphalt binders under the secondary aging condition were measured by the dynamic shear rheometer test and bending beam rheometer test.Effects of different types of warm-mix asphalt(WMA)technologies and additives were evaluated.Aging and improvement mechanisms were investigated by the Fourier transform infrared spectroscopy test.It is found that recycled binders after the secondary aging are more resistant to rutting and less resistant to low-temperature cracking.The two warm-mix asphalt technologies have opposite effects.Using the Sasobit WMA significantly improves the rutting resistance and reduces the low temperature resistance for the recycled binders due to its morphological change at different temperatures.The rutting factor values of recycled asphalt binders with the Sasobit additive increase by 4.6 to 5.6 times.However,using the Evotherm WMA causes the deterioration of the rutting resistance due to the structural lubrication effect.The rutting factor values of recycled asphalt binders with the Evotherm additive show the reduction of 52%to 62%.It is recommended to add the styrene butadiene rubber latex or crumb rubber powder into the warm-mix recycled asphalt binders to simultaneously improve the rutting and low-temperature cracking resistances.