Sexual behavior without adult morphogenesis inLocusta migratoria

Summary Injection of azadirachtin into young Vth (=last) instarLocusta hoppers inhibits molt and a considerable portion of the animals survice for more than 40 days as over-aged nymphs; in contrast, the duration of the Vth instar is 8–10 days in normal controls. Males of over-aged nymphs exhibit adult sexual behavior, and injection of juvenile hormone intensifies this behavior. The results demonstrate that the terminal molt leading to morphogenetic adult differentiation is not necessary for an adult behavioral pattern to develop, and/or to become overt, in a hemimetabolous insect.We thank Prof. H. Rembold for a generous gift of azadirachtin and Mr Y. Toren for keeping the locust culture.     

Sertoli cells of adult rats in vitro. II. Effect of different steroid precursors on estradiol 17β-synthesis

Summary The estradiol 17-synthesis by ⁴ pathway has been studied in homogenous cultures of Sertoli cells isolated from adult rat testes. The data reported clearly demonstrate that progesterone, androstenedione, testosterone and estrone induce an increase of the estradiol 17-production.This work was partially supported by grants No. 77.01322.04 and No. 77.01958.04 from the Consiglio Nazionale delle Ricerche.The excellent technical assistance of Antonio Muller and Massimo Rosati is deeply appreciated.     

High cell density alters the ratio of type III to I collagen synthesis by fibroblasts

HUMAN fibroblasts in culture synthesise both type I and type III collagen(1), with type I accounting for 70-90% of the total(2). In culture, the rates at which these proteins are synthesised is constant and apparently rather rigidly controlled(3). However, the proportions of these collagens differs in cells cultured with increased amounts of serum (increased type III/I)(4) as well as in cells obtained from patients with certain diseases. Cells from patients with the Ehlers-Danlos type IV syndrome make little or no type III collagen(5,6), whereas cells from patients with osteogenesis imperfecta have an increased type III/I (refs 7, 8). We have found that cells from some patients with systemic sclerosis (scleroderma), have a reduced type III/I ratio. However, as previously reported, these cells grew to a lower density than control cells(9). We report here that normal fibroblasts from human and guinea pig skin produce proportionally more type III collagen at high cell density, probably because of a reduction in the synthesis of type I collagen.     

Chemical protection of mouse spermatocytes against gamma-rays with 2-mercaptopropionylglycine

The radiosensitivity of primary spermatocytes in pachytene stage was estimated by counting the number of spermatids in the testes of control and MPG-treated mouse after exposure to 500, 1000 and 1500 R of Co60 gamma-rays. For this purpose, control and MPG-treated mice were killed 5 days after irradiation and countings of spermatids was made in stages I and II of the tubules. It has been observed that, although there was a death of primary spermatocytes in irradiated MPG-protected groups, quantitatively significant protection was afforded by this drug at all the 3 dose-levels studied.     

Suppression of delayed type hypersensitivity of mice by lead

Summary Application of lead suppressed the delayed type hypersensitivity (DTH) of mice induced by sheep red blood cells (SRBC). Inhibition of elicitation of DTH in primary as well as in secondary response was correlated with the concentration of lead in the blood of the mice.Acknowledgments. Supported by the Georg-und-Agnes-Blumenthal-Stiftung and the Verein für Wasser-, Boden- und Lufthygiene. We thank Miss Schachtschneider for the excellent technical assistance.     

Thiamine-quinone adducts. Colorimetric determination of thiamine

Summary 2, 3-dichloro-1,4-naphtoquinone reacts with thiamine in the presence of NH₃ to give a 12 adduct, for which structureII is proposed on the basis of analytical and spectroscopic (IR) data. Such a reaction is very useful for thiamine quantitative determination.     

Studies on lipid peroxidation using whole liver cells: Influence of damaged cells on the prooxidant effect of ADP-Fe3+ and CCl4

Summary An increase in the number of damaged cells produces an enhancement of lipid peroxidation induced by ADP-Fe³⁺ or CCl₄ in vitro on hepatocytes in single cell suspension.This work has been supported by the Consiglio Nazionale delle Ricerche, Roma, Italy, and the National Foundation for Cancer Research, Bethesda, Maryland, USA.     

Kelletinin I and kelletinin A from the marine molluscBuccinulum corneum are inhibitors of eukaryotic DNA polymeraseα

Summary The inhibitory effect of esters of p-hydroxybenzoic acid (kelletinins I and A), extracted from the marine gastropodBuccinulum corneum, have been tested on eukaryotic and prokaryotic enzymes of DNA metabolism such as DNA polymerases and , DNA polymerase I, Exo III, pancreatic DNAse I, micrococcal DNAse andE. coli RNA polymerase. Kelletinin I and kelletinin A inhibit preferentially DNA polymerase. The inhibitory effect of kelletinin I involves the hydroxyl group of p-hydroxybenzoic acid.     

心脏信号处理进展

本书是关于如何提取、分析心电图（ECG）信号不同特征的论文集，由南洋理工大学访问教授U．R．Acharya等四位学者主编。该书包含不同作者撰写的20篇论文，分为20个章节。这些论文论述了在不同阶段提取、分析心脏信号特征的方法，以及如何通过这些特征对心脏功能进行正确判断和分类。     

条形射频源大口径离子束刻蚀机性能(英文)

针对大尺寸基底往复扫描条形离子束来实现大面积刻蚀的特点,实验测试了基于射频感应耦合等离子体离子源大型离子束刻蚀机的性能.利用法拉第筒扫描探测系统在线测量束流密度,通过控制气体流量、调节加速电压等,得到了纵向束流密度±5.3%均匀性的较好结果.刻蚀实验表明40 cm长度范围刻蚀深度均匀性为±5.4%,同时具有较好的束流稳定性.添加束阑,并结合掩模修正束流,会得到更好的束流密度与刻蚀深度均匀性.