Synthesis and antitumour activity of new daunorubicin and adriamycin analogues

Summary A new synthetic procedure for the preparation of daunorubicin and adriamycin analogues bearing different substituents on ring D, has been developed. The new compounds display outstanding efficacy against experimental tumours of mice.     

Lipid sensing and lipid sensors

Lipid droplets have been considered for a long time as inert intracytoplasmic deposits formed within cells under various conditions. Recently, new tools and new approaches have been used to visualize and study these intracellular structures. This revealed new aspects of lipid droplets biology and pointed out their organized structure and dynamic composition. In adipocytes, the specialized cell type for the storage of energy as fat, lipid droplets are particularly well-developed organelles and exhibit unique properties. Also discussed in this paper is the view that lipid droplets, through specific candidate constituents, can play a role in sensing the level of their lipid stores by adipocytes.     

原子时频技术进展

概述了传统原子频标的现状,以及新型原子频标和国际原子时的研究进展。介绍了为适应高精度新型频标和国际原子时的比对需要而开展的远程时频传递技术。     

Human gene therapy: possibilities and limitations

Summary Gene therapy provides new options for medicine, and implies new responsibilities for making decisions relating to the limitations which reason and morality impose upon manipulation of the human genome for the benefit both of patients and of society. This contribution outlines the possibilities and limits of gene therapy in man from a medico-technical viewpoint.     

有机功能材料薄膜与器件

具有光、电、磁物理功能的有机材料的出现促进新思想、新概念、新材料的发展；有机功能材料的电子状态、导电机理以及杂质的影响完全有别于无机金属和半导体，因此，在深入探索结构与功能的关系的基础上，有可能开展分子、聚集态以及器件设计的研究。若与有机化合物的结构多样化，良好的加工性、成膜和成纤性等特点相结合，有可能实现无机电子材料所难兼具的电子行为。进而实现“分子电路”的设想。这里，我们对有机功能材料的基本概念、种类，功能材料薄膜的沉积、器件的构筑，分子电子学和分子器件的概念作了一个较为全面的介绍。     

AB型新单体及PBO树脂制备的新技术及其发展

研究以4,6-二硝基间苯二酚(DNR)和对苯二甲酸单甲酯(TAM)为原料,经三个单元过程合成AB型新单体:2-(对甲氧羰基苯基)-5-氨基-6-羟基苯并噁唑(MAB),进而均缩聚反应制备聚对苯撑苯并二噁唑(PBO)的新路线和新方法,设计了AB型新单体的产业化方案、并阐述了优于AA型单体4,6-二氨基间苯二酚(DAR)路线的特点;同时针对现有PBO技术中存在的问题,提出解决的方法和研究思路,最后对进一步发展AB型新单体:如4-(5-氨基-6-羟基-2-苯并噁唑)苯甲酸(ABA)和H2N-[PBO重复单元]-COOH结构等单体、以及高性价比PBO树脂的研究内容作了建议。     

Human gene therapy: possibilities and limitations

Gene therapy provides new options for medicine, and implies new responsibilities for making decisions relating to the limitations which reason and morality impose upon manipulation of the human genome for the benefit both of patients and of society. This contribution outlines the possibilities and limits of gene therapy in man from a medico-technical viewpoint.     

水煤浆供给泵磨损及排放性能研究

针对发动机上燃烧水煤浆内部磨损问题,运用缝隙流理论和高压油膜理论,设计一种新型喷水煤浆泵.分析了泵的润滑,并对原有的喷油泵及新型喷水煤浆泵喷射水煤浆后的柱塞偶件电子扫描照片进行对比,新型喷水煤浆泵柱塞偶件磨损明显减轻.在使用新型喷水煤浆泵基础上进行燃烧试验.研究表明:燃烧水煤浆和燃烧柴油相比,NOX排放下降明显,是燃烧柴油的20%;烟度排放略有下降;硫化物排放略有增加     

Cytosine modifications in neurodevelopment and diseases

DNA methylation has been studied comprehensively and linked to both normal neurodevelopment and neurological diseases. The recent identification of several new DNA modifications, including 5-hydroxymethylcytosine, 5-formylcytosine, and 5-carboxylcytosine, has given us a new perspective on the previously observed plasticity in 5mC-dependent regulatory processes. Here, we review the latest research into these cytosine modifications, focusing mainly on their roles in neurodevelopment and diseases.     

Intracellular cytoskeletal elements and cytoskeletons in bacteria

Within a short period of time after the discovery of bacterial cytoskletons, major progress had been made in areas such as general spatial layout of cytoskeletons, their involvement in a variety of cellfunctions (shape control, cell division, chromosome segregation, cell motility). This progress was achieved by application of advanced investigation techniques. Homologs of eukaryotic actin, tubulin, and intermediate filaments were found in bacteria; cytoskeletal proteins not closely or not at all related to any of these major cytoskeletal proteins were discovered in a number of bacteria such as Mycoplasmas, Spiroplasmas, Spirochetes, Treponema, Caulobacter. A structural role for bacterial elongation factor Tu was indicated. On the basis of this new thinking, new approaches in biotechnology and new drugs are on the way.     

Tuftsin and D-Arg3-tuftsin possess analgesic action

Summary Tuftsin has marked analgesic activity but is less potent than D-Arg³-tuftsin. The absence of an antagonistic effect of naloxone on tuftsin and its analogue suggests that these substances do not act on opiate receptors. Tuftsin and its analogues may represent a new class of substances of interest in the search for new analgesics.     

Choroidal vascular repair: Scanning and transmission electron microscopy

Repair of the choroidal vasculature following laser photocoagulation in the rat was examined with vascular casts and correlated with observations on thin-sections. The regenerative process began at the periphery of the damaged area, starting from the surviving choriocapillaris and venules, and proceeding towards the center by means of recanalization of damaged vessels and growth of new ones. In small healed lesions the capillary bed was re-formed. It resembled the adjacent undamaged choriocapillaris morphologically but appeared to be less dense than the intact choriocapillaris when examined by scanning microscopy. In large lesions the capillary bed was re-formed at the periphery but not at the center. Also present at the edges of the large lesions were groups of new vessels which, when observed by scanning microscopy, appeared to extend in two directions; towards the subretinal space and towards the choroidal network. Another aspect of the repair process was the simultaneous occurrence of new vessel growth and capillary regression, which was observed both at the level of the choriocapillaris and at the foci of new vessels     

Vidalols A and B,new anti-inflammatory bromophenols from the Caribbean marine red algaVidalia obtusaloba

Chemical studies of the Caribbean red algaVidalia obtusaloba have resulted in the isolation of two new bromophenolic metabolites, vidalols A and B (1, 2). The new compounds were discovered as part of an organized effort to isolate new naturally-occurring anti-inflammatory agents with a focus upon those which may function through the inhibition of phospholipase A₂.     

Choroidal vascular repair: scanning and transmission electron microscopy.

Repair of the choroidal vasculature following laser photocoagulation in the rat was examined with vascular casts and correlated with observations on thin-sections. The regenerative process began at the periphery of the damaged area, starting from the surviving choriocapillaris and venules, and proceeding towards the center by means of recanalization of damaged vessels and growth of new ones. In small healed lesions the capillary bed was re-formed. It resembled the adjacent undamaged choriocapillaris morphologically but appeared to be less dense than the intact choriocapillaris when examined by scanning microscopy. In large lesions the capillary bed was re-formed at the periphery but not at the center. Also present at the edges of the large lesions were groups of new vessels which, when observed by scanning microscopy, appeared to extend in two directions; towards the subretinal space and towards the choroidal network. Another aspect of the repair process was the simultaneous occurrence of new vessel growth and capillary regression, which was observed both at the level of the choriocapillaris and at the foci of new vessels.     

Things and the archives of recent sciences

With the interest in studying science as practice came an interest in the material artefacts and things that form part of scientific activities in the laboratory, the field, the classroom, or the political arena. This shift in interest in connection with new modes of knowledge production raises new questions regarding the “archive” of science: what should be preserved and where to make it possible to reconstruct scientific practices in the desired detail? While digital media may be able to bridge some of the traditional divisions between the collection of scientific artefacts in museums and the written archival depositories, the move to performing science in silico produces new challenges in respect to establishing the material archives of current science. The paper will discuss these and related questions with special reference to the archives of the contemporary life sciences.     

国内外从盐湖卤水中提锂工艺技术研究进展

金属锂及其化合物在能源和新材料方面具有重大应用前景,盐湖卤水提锂将成为21世纪锂盐生产的主攻方向。本文综合分析了国内外盐湖卤水提锂的工艺技术,提出了盐湖卤水提锂的发展趋势。     

Progressive reduction of neophobia during olfactory and gustatory experiments on dietary diversity in the adult rat

The ability of adult Rats to accept new foods does not depend only on varied or monotonous experience of diets offered during weaning. Grown-up Rats can get used to alimentary diversity and abate their neophobic behaviour to new foods.     

ConEntity：一种基于进程的自主并发实体编程模型及其实现

摘要本文在虚拟计算环境之上，研究支持具有自主能力、高并发的新型互联网应用开发方法，在已有的基于进程、面向并发的编程模型中引入实体建模机制，扩展出一种兼具进程和自主并发实体的程序设计模型ConEntity，并给出了形式化定义和描述．ConEntity模型具有表达性、并发性和可伸缩性的特点，能对虚拟计算环境资源高效、透明访问．通过扩展Erlang／OTP将其实现为Erlang语言设施UniAgent．本文的模型为在虚拟计算环境上快速直接构建具有自主、高并发能力实体的新型互联网应用提供了模型和语言上的支持．     

Ethylene production and cell wall formation in mesophyll protoplasts

Summary The regulation of ethylene synthesis, in relation to the presence of a new cell wall, has been investigated forNicotiana sylvestris leaf protoplasts. It is clear that the production of ethylene is not controlled by the new wall, which has no action on the ethylene formation. The addition of dichlorobenzonitrile to cultivated protoplasts causes the inhibition of wall formation, without any other apparent deleterious effects.