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21.
The inorganic contents of bone, brain, erythrocyte, heart, kidney cortex, kidney medulla, liver, lung, muscle and plasma from spontaneously hypertensive rats were compared with those of the same tissues from healthy Sprague-Dawley rats. A general inductively coupled plasma-mass spectrometry method developed for multi-element determinations of most of the elements present in biological tissues was used. Variations were found not only for major elements, as expected, but also for many trace elements in several tissues.  相似文献   
22.
Leaf and stem explants of Trillium grandiflorum and T. erectum produced mini-rhizomes (MRs) in vitro which gave rise to shoots and roots. The apical portion of the stem and the basal portion of the leaves were the most effective explants from these tissues, while stem tissue was more responsive than leaf tissue. The best response with both species was observed on half-strength MS basal medium supplemented with cytokinin and auxin. T. erectum was more responsive than T. grandiflorum overall, and in some cases produced MRs in the absence of growth regulators. Culture at 21°C appeared to stimulate growth from T. grandiflorum tissues, compared with controls at 27°C, whereas the outgrowth of shoots from MRs was inhibited in both species at 21°C. In vitro production of MRs could provide a more rapid, alternative propagation method for these species than traditional methods.  相似文献   
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24.
Artichoke yellow ringspot nepovirus (AYRV) was isolated from stunted broad bean plants in Crete showing leaf mottling and deformation and wrinkling of seed testas. AYRV identification was based on host range, behaviour during purification, electron microscopy and serology. AYRV-broad bean isolate was seed-transmitted in broad bean, and embryo infection appeared to be a prerequisite for virus transmission to seedlings. Transmission through pollen was not detected in broad bean plants, although pollen grains were externally contaminated by the virus. Ovule infection occurred in a high proportion of seed and was independent of pollination.  相似文献   
25.
The BBCH (Biologische Bundesanstalt, Bundessortenamt, Chemische Industrie) scale is used to describe the phonological growth stages of North American ginseng (Panax quinquefolius). Eight principal growth stages for germination and bud development, leaf development (crop canopy), root and perennating bud formation, peduncle elongation and inflorescence development, flowering and fruit set, development of fruit, ripening of fruit and senescence, and 42 secondary growth stages are described. A practical use of the scale is proposed with reference to the timing of application of agrochemicals for disease control.  相似文献   
26.
Using antibodies raised against two sunflower small heat shock proteins (sHSPs), we have detected immunologically related proteins in unstressed vegetative tissues from the resurrection plant Craterostigma plantagineum. In whole plants, further accumulation of these polypeptides was induced by heat-shock or water-stress. In desiccation-intolerant Craterostigma callus tissue, we failed to detect sHSP-related polypeptides, but their expression, and the concurrent acquisition of desiccation tolerance was induced by exogenous abscisic acid (ABA) treatment. In untressed plants, the cross-reacting polypeptides were abundant in the roots and lower part of the shoots, where they showed homogeneous tissue-distributions. This constitutive expression is novel for vegetative tissues of higher plants, and resembles the expression patterns of sHSPs in desiccation-tolerant zygotic embryos and germinating seeds.J.A. and C.A. contributed equally to this work and are both considered to be first author  相似文献   
27.
The possible use of vanadium compounds in the treatment of diabetic patients is now being evaluated. However, previously to establish the optimal maximum dose for diabetes therapy, it should be taken into account that vanadium is a highly toxic element to man and animals. The toxic effects of vanadium are here reviewed. The tissue vanadium accumulation, which would mean an additional risk of toxicity following prolonged vanadium administration is also discussed. Recently, it has been shown that coadministration of vanadate and TIRON, an effective chelator in the treatment of vanadium intoxication, reduced the tissue accumulation of this element, decreasing the possibility of toxic side effects derived from chronic vanadium administration without diminishing the hypoglycemic effect of vanadium. However, previously to assess the effectiveness of this treatment in diabetic patients, a critical reevaluation of the antidiabetic action of vanadium and its potential toxicity is clearly needed.  相似文献   
28.
本文是利用扫描电子显微镜对陆栖恐龙tvrannosaurid与海栖渐增mosasaurid”牙齿结构进行的比较解剖学研究。化石采自加拿大RedDeerhiverValley上白里统Horse-shoeCanyon组。通过研究地层中出现的生物化石,特别是动物牙齿的组织结构,可以了解动物为了适应生活环境而发生的进化过程,也可以推测它们的系统发育关系。tyrannosaund与mosas。id都拥有锥状的同形齿,牙齿侧向扁平,且略向后弯曲。研究结果确认了tyrannosaurid的牙齿由于薄层的无柱釉质bPrismaticenamel)向齿质的侵人而造成许多的凹凸构造,此锯齿状构造沿着牙齿的前后缘,由牙齿的顶端分布至基部。因此tyrannosaurid的牙齿呈现着锐利的切缘;在这些凹凸状切缘的沟与小窝的深部可观察到有机物的沉积。但是类似的锯齿状构造只能在齿冠呈钝圆状的mosasaurid牙齿的基部附近观察到。我们以扫描电子显微镜(SEM)检索,确认两爬行类的齿质皆是属于中间型的真性齿质(intermediatetypeorthodentine);所谓orthodentine即是细管齿质(tubulardentine)。tyrannosaurid的真性齿质的齿质小管只在齿质一釉质相接处Uentino—enamaljunction)附近放散出规则性的分歧与末枝。但mosasaurid的真性齿质的齿质J。管,在齿质的中间层与表层中,呈现着由复杂  相似文献   
29.
张石宝  魏兆祥   《广西植物》1997,17(2):162-165
本文对观赏植物异色芋(ColocasiaheterochromaH.LietZ.X.Wei)在昆明栽培环境下的生物学特性进行总结,为商品化栽培异色芋提供了理论依据,为其分类也提供了一定的有益补充。结果表明:一年生植株不开花,根茎也不产生分枝;二年生植株开花率为73.6%,根茎平均分枝3.6条。异色芋3月上旬开始萌动,7月中旬抽花梗,8月上旬开花,11月份地上部分枯萎,因此在昆明异色芋生育期约260d。  相似文献   
30.
A procedure for the immunoassay of cohydrolase sphingolipid-I in mouse tissue is described. This cohydrolase (actually a mixture of at least four related proteins) stimulates or activates the beta-glucosidase which hydrolyzes ceramide glucoside, a widely occurring glycosphingolipid. The method involves extraction of cohydrolase from tissue homogenate with a salt-buffer solution, removal of proteins by adjustment to pH 6, further removal of proteins by heating, and removal of interfering materials with a small size exclusion column. Antibodies were raised to bovine cohydrolase in rabbits and purified with an affinity column made from cohydrolase. The immunoassay involves binding of antibody by the cohydrolase sample (20-200 pg) in competition with cohydrolase that has been chemically linked to horseradish peroxidase. The mixture is treated with particle-linked second antibody and centrifuged; the pellet is then assayed fluorometrically for peroxidase content. Initial application of the method showed that cohydrolase was present in all mouse tissues studied and that its concentration paralleled that of glucocerebrosidase relatively closely. Changes with age (14 and 92 days) occurred in a similar fashion for the two substances.  相似文献   
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