The margin of overgrowth of the embryonic chick blastoderm as a study model for cell-to-cell contacts

Zusammenfassung Die Entwicklung vom «margin of overgrowth» junger Hühnerkeime ist verschieden nach Kontakt mit Helazellen und mit Mesonephros oder Hautgewebe; die ersteren hemmen die Entwicklung, die anderen werden vom Keim aufgenommen. Deshalb wird der «margin of overgrowth» als Modell für die Studie von Zellkontakten vorgeschlagen.     

高取向热解石墨纳米孔的制备、控制及纳米结构的模板合成

高取向热解石墨（HOPG）单层及多层纳米可作为结构模板合成金属或半导体纳米结构。本文介绍了作者最近有关用高聚焦离子束轰击和热氧化法在HOPG上制备大小、深度（单层、多层）、密度可控的纳米孔,以及控制纳米孔的形成位置制备周期性的纳米孔有序阵列等工作。并对用HOPG纳米孔作为结构模板合成金属或半导体纳米结构及其有序阵列体系也作了介绍。     

Oriented mycelium growth of the fungusPoria vaillantii (DC) Sacc. in mixed culture with spruce callus

Summary Metabolites with inhibiting action, which are secreted into the substrate by the spruce callus, provoke in the fungusPoria vaillantii a subsequent production of aerial mycelium bundles. Their orientation, right-handed negative chemotropism with a certain deflection from the callus, is included in this reaction.     

Comparative studies on the covalent binding of the carcinogen benzo(a)pyrene to DNA in various model systems

Summary The covalent binding of tritiated benzo(a) pyrene (BP) to DNA has been determined in rat liver in vivo, in rat liver perfused in situ, after incubation of BP with liver single cells, with liver homogenate, with liver microsomes and DNA, with fibroblasts from a rat granuloma pouch, and with 2 cell lines. Liver single cells were found to be a valuable compromise between the most sensitive system (microsomal incubation of BP with DNA) and the biologically most relevant system (in vivo).Presented in part at the 10th Annual Meeting of the Union of Swiss Societies of Experimental Biology, Experientia34, 925 (1978), abstract.Acknowledgment. We thank Dr G. Kistler, Institute of Anatomy, University of Zurich, for generously supplying the SIRC and VERO cell lines, and Mr P. Manser for the preparation of the granuloma pouch fibroblasts.     

Macrobiotus pseudohufelandi Iharos as a model for cytotaxonomic study in populations of eutardigrades (Tardigrada)

Summary The morphotype, chromosome number and Feulgen-DNA content of bisexual and unisexual populations ofMacrobiotus pseudohufelandi were examined. Individuals of unisexual populations were triploid with ameiotic parthenogenesis. Their lowest Feulgen-DNA content is about three-fold that of sperm from a bisexual population. Egg shell shape also differs in the two types of population. However, the highest Feulgen-DNA content was the same (24 A.U.) in both diploid and triploid animals.Study funded by MPI grant.     

Comparative studies on the covalent binding of the carcinogen benzo(a)pyrene to DNA in various model systems.

The covalent binding of tritiated benzo(a)pyrene (BP) to DNA has been determined in rat liver in vivo, in rat liver perfused in situ, after incubation of BP with liver single cells, with liver homogenate, with liver microsomes and DNA, with fibroblasts from a rat granuloma pouch, and with 2 cell lines. Liver single cells were found to be a valuable compromise between the most sensitive system (microsomal incubation of BP and DNA) and the biologically most relevant system (in vivo).     

Effect of organophosphate pesticide Sumithion (Fenitrothion) on some aspects of carbohydrate metabolism in a freshwater fish,Sarotherodon (Tilapia)mossambicus (Peters)

Summary A lethal (Lc₅₀/48 h — 6 mg/l) concentration of the organophosphate (OP) pesticide Sumithion increased blood glucose levels and phosphorylase activity, but hepatic glycogen registered a fall which indicated that the observed hyperglycemia was due to breakdown of hepatic glycogen.This work was supported by UGC grant to R.R.     

Effect of organophosphate pesticide Sumithion (Fenitrothion) on some aspects of carbohydrate metabolism in a freshwater fish, Sarotherodon (Tilapia) mossambicus (Peters)

A lethal (Lc50/48 h - 6 mg/l) concentration of the organophosphate (OP) pesticide Sumithion increased blood glucose levels and phosphorylase activity, but hepatic glycogen registered a fall which indicated that the observed hyperglycemia was due to breakdown of hepatic glycogen.     

Locomotory energetics in a marsupial (Antechinomys spenceri) and a rodent (Notomys alexis)

Summary Steady state oxygen consumption was compared in a rodentNotomys alexis and a marsupialAntechinomys spenceri. The marsupial was found to diverge from predicted eutherian energetic patterns.N. alexis appears to use energy storage as a significant part of the step cycle before becoming bipedal. Aerobic scope and heat storage during running are similar in both species.We thankP. Baverstock, C. Watts andH. Aslin for the use of theAntechinomys, Ms.B. Whaite for assistance. Supported by Grants from the Nuffield Foundation, the Ingram Trust and the Flinders University Research Committee to RVB.     

Effects of benzo(a)pyrene on isolated rat liver mitochondria

Riassunto Viene trattato mitocondri isolati di fegato di ratto con una soluzione acquosa di benzo(a)pyrene. I mitocondri cosi trattati appaiono rigonfi, hanno matrici chiare e notevole aumento degli spazi mannitolo-impermeabili. Queste modificazioni sono verosimilmente dovute all'azione del benzo(a)pyrene sulle molecole fosfolipidiche delle membrane motocondriali.     

聚合质量比对Sr0．7La0．15Ce0．15Fe11.7Zn0．3O19／PAn复合体系微波吸收性能的影响

用原位聚合法制备了Sr0．7La0．15Ce0．15Fe11.7Zn0．3O19铁氧体／聚苯胺（PAn）复合材料。采用X射线衍射（XRD）、扫描电子显微镜（SEM）对样品的结构、微观表面形貌和粒子大小进行了表征,用微波矢量网络分析仪测量样品在2～12．4GHZ频率范围内复介电常数和复磁导率,根据测量数据计算微波反射率R与频率f的关系。研究结果表明：PAn包覆于掺杂锶铁氧体表面,PAn／Sr0．7La0．15Ce0．15Fe11.7Zn0．3O19复合材料具有良好的吸波性能,随着掺杂锶铁氧体含量的增加,微波吸收匹配厚度和吸收带宽发生变化：当Sr0．7La0．15Ce0．15Fe11.7Zn0．3O19聚合质量比为40％时,最佳匹配厚度为2．6mm,吸收峰值接近-40dB,峰值频率高于12．4GHz,大于10dB吸收带宽预计达到55GHz。