上海天文台1.56米天体测量望远镜若干性能的观测测试

上海天台1.56米天体测量望远镜在1988-1989年间作了若干性能观测,本阐明了其测试的方法和结果,并对这回望远镜的天体测量使用提供了某些参考意见。     

THE ULTRASTRUCTURE OF SEPARATED AND CULTURED CELL OF PORPHYRA YEZOENSIS

There are many reports that cells (protoplasts) separated from the thallus of Porphyra by enzyme can develop to normal leafy thalli in the same way as monopores. But there are few investigations on the subcellular structure of the isolated vegetative cell for ccmparison with the subcellular structure of monospores. To clarify whether the separated and cultured cells undergo the same or similar ultrastructure changes during culture and germination as monospores undergo in their formation and germination, we observed their ultrastructure, ccxnpared them with those of the monospore and found that the ultrastructure of separated and cultured cells did not have the characteristic feature as that of monospore formarion, such as production of small and large fibrous vesicles, but was acccxnpanied by vacuolation andstarch mobilization like that in monospore germination. The paper also discusses the relations between monospores and separated and cultured cells.     

Siderophores from Marine Microorganisms and Their Applications

1　Introduction　Ironisanessentialelementwhichisdifficulttoob tainduetoitslowsolubilityunderthephysiologicalconditions ,anditisalsothemostimportanttransitionmetalionfornearlyalllivingsystems.Manypatho genicbacteriausuallyobtainironfromtheiron bind ingprot…     

开花后淹水对小麦旗叶叶肉细胞及产量的影响

选用小麦品种济麦20和泰农18,采用池栽补灌淹水方法,研究开花期及灌浆期3、6、9、12d淹水对小麦旗叶叶肉细胞形态及籽粒产量的影响.开花期淹水,减少叶肉细胞的裂解,延缓了旗叶衰老;灌浆期淹水,则加剧了叶肉细胞的裂解,旗叶的衰老加速.除淹水3d外,两时期6-12 d淹水均引起籽粒产量降低.产量降低的主导因素是粒数的减少,其次是粒重的降低.     

NEW OBSERVATIONS ON THE MEIOTIC PROCESS IN THE MARINE DINOFLAGELLATE NOCTILUCA SCINTILIANS （NOCTILUCALES, DINOPHYCEAE）

The meiotic process in Noctiluca scintillans were observed under light microscope.Some abnormal cell divisions, incompletely separated “zoospores” and the changes of the zoospores are described in this paper. Together with the fmdings of field samplings and the previous results by other researchers, the process of meiosis in N. scintillans was supposed to be a pathway to reduce the extra high density of NH3-N within the cell in order to ensure normal population growth.     

Observation of female gamete （Carpogonia） germination of Porphyra yezoensis and P. oligospermatangia

Several papers have reported that part or whole leafy thallus seemingly consisting of zygotospores can give rise to both blades and conchocelis in the same culture of Porphyra. Study on samples of wild and cultivated Porphyra yezoensis and P. oligospermatangia were conducted to clarify the origination of the young blades in the culture. It is confirmed that single cells on the blade of both species, which normally intermixed with zygotospores, germinated into young blades. TEM and SEM observation has shown that the single cells of Porphyra yezoensis had typical features of female gamete （carpogonia） but archeospore. Therefore, the female gametes are responsible in developing leafy thalli.     

不同条件延缓未受精卵激活对鱼类细胞电融合的影响

泥鳅未受精卵先在合成卵巢液、郝氏液中分别浸泡15、20、30min,然后再受精孵化,统计发育情况,结果表明,合成卵巢液可有效延缓未受精卵遇水后被激活的时间,郝氏液对延缓未受精卵被激活也有一定作用,但效果比合成卵巢液差。用合成卵巢液配制不同浓度胰酶处理受体卵进行细胞电融合实验,胰酶质量浓度为5 mg/mL时,融合卵发育至囊胚期的比例比对照组(郝氏液)高2%,统计分析表明该差异是显著的(P<0.05);但发育至原肠期及孵出期的比例则与对照组无显著差异。胰酶质量浓度为2和1 mg/mL时,融合卵发育到各阶段的比例均低于对照组,统计分析表明两者的差异是显著的(P<0.05)。研究表明,溶液种类、胰酶浓度等对电融合卵的发育有明显的影响,但延缓受体卵的激活时间并不能提高电融合卵的出苗率。用郝氏液配制的2 mg/mL的胰酶溶液处理受体卵,可获得较高比例的融合鱼。     

杀死致病菌的“斗士”

抗生素是人类的一项极为重要的发现，它是人类战胜致病菌的重要武器。但是，随着抗生素的使用，问题也随之而来。许多细菌在其进化过程中，找到了抵制抗生素的方法，比如分泌酶来降解抗生素，或是利用其他工具将抗生素“驱逐”到细胞外。致病菌对抗生素的抗性成为许多疾病（如肺炎）治疗的障碍。绿脓杆菌可引起耳部感染，这种致病菌可制造一种由糖和蛋白组成的生物膜，然后用生物膜把自己包裹起来，其抵抗抗生素的能力将增加1000倍。     

科技短消息

癌细胞进入大脑的"单程票"?有10%的癌症患者的癌细胞会扩散至脑部并发展成脑部肿瘤。一个一直困扰着学术界的问题是:癌细胞是如何通过血脑屏障的?血脑屏障是中枢神经系统中的一种细胞结构,它可以限制化学物质和     

Ⅰ、激素的适宜种类和浓度对海水单胞藻生长的影响

选择了三类六种植物激素，试验了五种常用于鱼、虾、贝的活饵料——海水单细胞藻，证明了增产素、乙烯利对亚心形扁藻和钙质角毛藻的生长有增效作用。以10—50ppm增产素处理亚心形扁藻的净增产率为40—70％，并对细胞大小产生影响，它的细胞长度增加3-14％，宽度增加4—7％。