Réflexions critiques sur l'écologieet la systématique des Lingules actuelles et fossiles

New topics on ecology and systematics of recent and fossil Lingulids lead to an obvious revision of our knowledges on this zoological group. At first, the recent species need systematics and taxonomy on the bases of new described specific criteria (as, morphology of deltidial areas, muscle disposition); the results are briefly indicated. But, in fossil species, disorder and disparity of used characteristics are emphasized.The general conceiving on ecology of Lingulids are reviewed and discussed, especially on bathymetry and salinity; sediment and oxygenation conditions; taphocoenosis and lingulid «communities. On recent species, all these points are also studied, especially some ecological requirements (salinity, bathymetry, grain size), and mechanism of burrowing ability, burrow living positions in the sediments, as shell preservations after death and fossilization, to facilitate the paleobiotope interpretations. Recent animals are euryhalin, surviving at salinities from about 13 to 42‰; they could be considered as well adapted to waters with strong salinity fluctuations. They show preference to fine sand bottoms (lowest particle size about 40–60 μm). Their bathymetric distribution occurs between 0 and about 500 m (Lingula especially between 5–50 m; Glottidia 15–70 m). The isotherms 8–10°C seem to restrict their geographical and bathymetric distribution.Therefore, some post-palaeozoic lingulid bedsare studied or redescribed on the bases of the above discussed characteristics, and new interpretations on the environmental situation are given (Trias of Vosges Mountains; Oligocene from Japan; Eocene of London Basin). More caution must be used in study of fossil Lingulids that are not especially animals living in infralittoral bottoms with low salinity and deficient oxygenation, as generally accepted.     

Diastereomeric Process Control in the Synthesis of 2′-O-(2-Methoxyethyl) Oligoribonucleotide Phosphorothioates as Antisense Drugs

Abstract

Coupling of 2′-O-methoxyethylsubstituted nucleoside phosphoramidites to 5′-hydroxyl group of a nucleoside or nucleotide on solid support is under stereochemical process control and is independent of scale, concentration, synthesizer, ratio of amidite diastereomers, solid support etc. However, activators and phosphate protecting groups do play a role in influencing the ratio of phosphorothioate diesters obtained by sulfurization of phosphite triesters.     

PLK1 与妇科肿瘤的研究进展

人类肿瘤生成过程由很多复杂环节组成,其主要现象表现为细胞分裂增殖的失调控生长。细胞分裂都必须按照正常细胞程序的每一个步骤进行才能保证机体的正常运转,细胞周期依赖分子PLK1是调节正常细胞有丝分裂、胞质分裂,以及对DNA受损伤后进行一系列反应调节的重要因子。它在细胞周期中的作用已有多位学者共同认识,当细胞失调控时检测到PLK1存在过量的表达,同时大量研究表明,人类PLK1基因不仅在多种已发现的恶性肿瘤中有此现象,而且在一些肿瘤中,它关系到这些肿瘤的发生发展及预后,被认为其可能成为一种新的肿瘤标志物,还可作为肿瘤定向分子靶向治疗中的一个有效目的基因的靶点,并且近年来对PLK1在肿瘤基因蛋白靶向治疗方面的药物研究开发已经成为学者研究的一个热点方向,该文对近年来PLK1在肿瘤生成中的作用,特别是其与妇科肿瘤关系方面的一些研究进展予以以下阐述。     

Process analytical technologies to monitor the liquid phase of anaerobic cultures

Recent advances in sensor development and miniaturization offer new possibilities to monitor and control bioprocesses. Specific requirements for anaerobic processes in terms of low costs and high robustness against insoluble fractions and impurities in media led to a decelerated penetration of new technology in this field. Since no regulatory framework demands for process monitoring and documentation like in the pharmaceutical industry, the implementation of new sensors beyond long-established methods is not conducted as intensively.Nevertheless, many attempts have been made in recent years to adopt sensors and show their applicability in anaerobic fermentation processes. New possibilities arise for improved monitoring, control and faster process development through digitalization. This review aims to provide an overview over these recent attempts with the focus on the liquid phase in the upstream part of pure culture bioprocesses for anaerobic bulk compound, food, and beverage production. In particular, methods that monitor the viability, metabolic activity or related parameters are discussed, like electrochemical, impedance and spectroscopy probes, and methods related to fluid flow and gradient formation, like acoustic and mobile sensors.     

Advances in thermochemical conversion of woody biomass to energy,fuels and chemicals

Biomass has been recognised as a promising resource for future energy and fuels. The biomass, originated from plants, is renewable and application of its derived energy and fuels is close to carbon-neutral by considering that the growing plants absorb CO₂ for photosynthesis. However, the complex physical structure and chemical composition of the biomass significantly hinder its conversion to gaseous and liquid fuels.This paper reviews recent advances in biomass thermochemical conversion technologies for energy, liquid fuels and chemicals. Combustion process produces heat or heat and power from the biomass through oxidation reactions; however, this is a mature technology and has been successfully applied in industry. Therefore, this review will focus on the remaining three thermochemical processes, namely biomass pyrolysis, biomass thermal liquefaction and biomass gasification. For biomass pyrolysis, biomass pretreatment and application of catalysts can simplify the bio-oil composition and retain high yield. In biomass liquefaction, application of appropriate solvents and catalysts improves the liquid product quality and yield. Gaseous product from biomass gasification is relatively simple and can be further processed for useful products. Dual fluidised bed (DFB) gasification technology using steam as gasification agent provides an opportunity for achieving high hydrogen content and CO₂ capture with application of appropriate catalytic bed materials. In addition, multi-staged gasification technology, and integrated biomass pyrolysis and gasification as well as gasification for poly-generation have attracted increasing attention.     

Use of Terrestrial Invertebrates as Indicators of the Ecological Sustainability of Forest Management under the Montreal Process

Twelve nations involved in boreal or temperate forest management are committed to reporting on indicators under the Montreal Process as a mechanism for assessing progress towards sustainable forest management. For fauna, invertebrates are often considered too poorly known and diverse to include in sustainability indicator reporting. The alternative view, that no monitoring of sustainability can be considered adequate without inclusion of some invertebrate species, is espoused in this paper. The microhabitats of soil and litter, foliage and canopy, bark and branch, dead standing trees and coarse woody debris are highlighted as relevant in the context of determining the impacts of forest management on invertebrates and for selecting representative species. It is argued that a selection of those species from each of the key microhabitats that are restricted to later stages of succession should be monitored. This could be complemented by a selection of easily monitored species from a range of functional groups as a means of endeavouring to pick up adverse impacts not foreseen on the basis of present knowledge. In the longer term, habitat indices (developed from predictive models of fauna habitat) should be used to monitor the occurrence of indicator species across the broader landscape, rather than at specific sites where monitoring of species takes place. Most countries would be in a position to select indicator species and commence monitoring for some key microhabitats (e.g. soil and litter). However, further research is needed in many countries before indicator species can be selected for other key microhabitats (e.g. coarse woody debris).     

区域农业综合生产力的AHP-Fuzzy综合评判

根据系统分析原理,在确定区域农业综合生产力系统的层次结构基础上,用层次分析法确定各因素的权重,用模糊多级综合评判法对各区域综合生产力进行综合的评价．具有一定的科学性和实用价格．     

冻干腮腺炎活疫苗细胞培养生产工艺研究

报告了冻干腮腺炎活疫苗细胞培养生产工艺研究结果,通过对鸡胚疫苗株的适应培养及对细胞培养生产工艺的试验优化,建立了连续细胞培养多次收获疫苗生产工艺并制备出了冻干细胞培养腮腺炎活疫苗制剂。本生产工艺切实可行,生产成本低、投入产出率高,所用原材料规范、质量易于控制,具有明显的技术优势。生产的冻干疫苗制剂质量稳定可靠,符合中国生物制品规程要求,有利于预防腮腺炎的规模化推广使用     

Predictions of matrix‐assisted refolding of α‐lactalbumin: Process efficiency versus batch dilution method

Protein refolding is an important technique to produce active recombinant proteins from inclusion bodies. Because of the complexity of the refolding process, a trial‐and‐error method is usually used for its design, which is ineffective and time consuming. Therefore, an efficient method for the process prediction is indispensable to optimize the operating conditions. In this article, we suggest a design procedure for matrix‐assisted protein refolding. Three different chromatographic techniques were considered exploiting hydrophobic interaction chromatography, ion‐exchange chromatography, and SEC media. The procedure consisted of quantification of refolding kinetics, analysis of the retention behavior of all protein forms involved in refolding, construction of a dynamic model, and the process simulation. Denatured bovine α‐lactalbumin was used as model protein. The refolding rate was measured for different protein concentration using the batch dilution method. A kinetic scheme for the protein refolding was suggested and incorporated into a dynamic model of chromatographic column and used for predicting the refolding performance. The productivity, yield, and buffer consumption were used as performance indicators for the refolding techniques considered. The matrix‐assisted protein refolding process outperformed batch dilution method with respect to all indicators provided that efficient method for the process design was used.