成骨肿瘤细胞在纳米氧化钛陶瓷表面的生物活性研究

以羟基磷灰石和氧化镁为晶粒生长抑制剂制备的纳米氧化钛陶瓷为研究对象, 采用体外成骨细胞Ros17/28与材料复合培养的方法, 通过MTT法、荧光染色法和SEM细胞形貌观察等手段综合判断细胞在材料表面的活性, 以此评价纳米氧化钛陶瓷的生物活性. 结果表明, 以羟基磷灰石为晶粒生长抑制剂的氧化钛陶瓷晶体颗粒尺寸达到纳米级, 其生物活性超出了以氧化镁为晶粒生长抑制剂的氧化钛陶瓷和纯羟基磷灰石陶瓷, 具有优异的生物相容性, 是生物活性陶瓷.     

Evaluation of Vetiver Volatile Compound Production under Aeroponic-Grown Conditions for the Perfume Industry

Vetiver (Chrysopogon zizanioides (L.) Roberty) is a major tropical perfume crop. Access to its essential oil (EO)-filled roots is nevertheless cumbersome and land-damaging. This study, therefore, evaluated the potential of vetiver cultivation under soilless high-pressure aeroponics (HPA) for volatile organic compound (VOC) production. The VOC accumulation in the roots was investigated by transmission electron microscopy, and the composition of these VOCs was analyzed by gas chromatography coupled with mass spectrometry (GC/MS) after sampling by headspace solid-phase microextraction (HS-SPME). The HPA-grown plants were compared to plants that had been grown in potting soil and under axenic conditions. The HPA-grown plants were stunted, demonstrating less root biomass than the plants that had been grown in potting soil. The roots were slender, thinner, more tapered, and lacked the typical vetiver fragrance. HPA cultivation massively impaired the accumulation of the less-volatile hydrocarbon and oxygenated sesquiterpenes that normally form most of the VOCs. The axenic, tissue-cultured plants followed a similar and more exacerbated trend. Ultrastructural analyses revealed that the HPA conditions altered root ontogeny, whereby the roots contained fewer EO-accumulating cells and hosted fewer and more immature intracellular EO droplets. These preliminary results allowed to conclude that HPA-cultivated vetiver suffers from altered development and root ontology disorders that prevent EO accumulation.     

An HPLC method for the determination of selected amino acids in human embryo culture medium

A method for the determination of selected amino acids in culture medium using HPLC with fluorescence detection is described. Twenty hours after intra‐cytoplasmic sperm injection, one randomly selected zygote was transferred to the culture medium. After incubation (72 h after fertilization), the culture medium in which the embryo was incubated and blank medium was immediately stored at −80°C. Filtered medium samples were derivatized with ortho ‐phthalaldehyde (naphthalene‐2,3‐dicarboxaldehyde), forming highly fluorescent amino acids derivatives. Reverse‐phase columns (LichroCART, Purospher STAR RP_18e or Ascentis Express C₁₈) were used for the separation. The derivatives were analyzed by gradient elution with a mobile phase containing ethanol and sodium dihydrogen phosphate. The analytical performance of this method is satisfactory for all amino acids; the intra‐assay coefficients of variation were <10% and quantitative recoveries were between 95.5 and 104.4%. Changes in the levels of selected amino acids before and after human embryo cultivation were observed. After embryo incubation, the levels of all amino acids in the medium were increased, apart from aspartate and asparagine. After the cultivation of some embryos, amino acids which were not part of the medium were detected. Low amino acids turnover was observed in some embryos.     

A specific standard for quality in fundamental research

 The specific standard described here constitutes the heart of the quality system set up by the Commissariat à l'Energie Atomique – French Atomic Energy Commission – for its main "Fundamental Research" entity, the Directorate for the Sciences of Matter. It is a coherent standard (set of shared rules and provisions laid out in a clear fashion) designed, in the first instance, to provide those taking part in research, including the hierarchy, with the means to satisfy their requirements in the field of quality. And, secondly, to create the conditions for recognition of this action by third parties, which all research entities must nowadays convince of their trustworthiness (supervisory ministries, research partners, industrial companies, etc.). This standard places particular emphasis on the preponderant roles of initiative and freedom in fundamental research, which are a prerequisite for creativity, innovation and, last but not least, the motivation of personnel.     

Workshop on "Quality Management in Analytical Chemical Research and Development"

 Maintaining a high quality of research and development (R&D) is fundamental for the competitiveness of European industry. The development of new technologies and the improvement of existing technologies, products, production processes, measurement instrumentation and methods as well as basic research is essential. The objective of the workshop on "Quality Management in Analytical Chemical Research and Development" was to bring together experts from the academic world, industrial and institutional laboratories and also accreditation bodies to discuss the actual state of the art in the field of quality management in R&D, and to set up milestones for further activities. Furthermore, an important objective was to present the EURACHEM/CITAC Guide 2. The paper outlines the programme of the workshop and summarises the round-table discussions and expert recommendations. Most of the contributions to the round-table discussions will be published as full papers in a forthcoming issue of Accreditation and Quality Assurance. The workshop was organised by the Institut für Chemo- und Biosensorik (ICB), Münster, with the financial support of the SMT-Programme of the European Commission (Contract No.: SMT4-CT98-6534).     

The quality approach and fundamental research: Working towards a constructive alliance (Part II)

 An appropriate Quality approach in fundamental research should have its roots in the very principles of the "scientific method". Quality and fundamental research could thus reconcile at the condition, on the one hand, that Quality practioners understand and take into account the reality of the "science in action" and, on the other hand, that scientists improve their awareness of the new deal which is being made between science, technology and society as well as of the actual issues of Quality. A modern Quality approach, well adapted to this specific activity, should help both scientists, decision-makers and the public face the issues concerning the role of science in society in the future. In this context, I specify a number of practical proposals concerning, in particular, the adaptation of the requirements of the quality approach to the type of research, the distinction between the three major steps of a research programme (i.e. quality of the objective, the process and the results) and the encouragement of experience feedback. Received: 8 March 1998 / Accepted: 8 December 1998     

A combination of accreditation and certification in an evolving process at EMPA: A management system to meet ISO 9001, ISO 14001 and EN 45001

 The Swiss Federal Laboratories for Materials Testing and Research (EMPA) have established a quality assurance system based on EN 45001 which meets the requirements for accreditation of all EMPA's testing activities. As testing is only a part of EMPA's range of activities, and is performed in decentralised departments, the system does not satisfy the management needs. The fundamental reorganisation of EMPA's St. Gallen site was used as an opportunity to implement an overall process-oriented management system which also included quality and the needs for accreditation. Later, an environmental management system was added and then certified for ISO 9001 and 14001. The system consists of a "Management Manual" for the St. Gallen site and a customised "Quality Manual" for each department. One of the key elements is a comprehensive review and planning procedure covering all business aspects.