Polysaccharide‐based artificial extracellular matrix: Preparation and characterization of three‐dimensional,macroporous chitosan,and heparin composite scaffold

Scaffold‐guided tissue engineering based on synthetic and natural occurring polymers has gained many interests in recent year. In this study, the development of a chitosan‐heparin artificial extracellular matrix (AECM) is reported. Three‐dimensional, macroporous composite AECMs composed of heparin (Hep) and chitosan (Chito) were prepared by an interpolyelectrolyte complex/lyophilization method. The Chito‐Hep composite AECMs were, respectively, crosslinked with glutaraldehyde, as well as cocrosslinked with N,N‐(3‐dimethylaminopropyl)‐N′‐ethyl carbodiimide (EDC/NHS) and N‐hydroxysuccinimide (NHS). The crosslinking reactions were examined by FT‐IR analysis. In physiological buffer solution (PBS), the EDC/NHS‐crosslinked Chito‐Hep composite AECM showed a relative lower water retention ratio than its glutaraldehyde‐crosslinked counterparts. The EDC/NHS‐crosslinked Chito‐Hep composite AECMs showed excellent biocompatibility, according to the results of the in vitro cytotoxic test. This result suggested that the EDC/NHS‐crosslinked Chito‐Hep composite AECMs might be a potential biomaterial for scaffold‐guided tissue engineering applications. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Variability in the interpretation of thorax radiography in a primary care medical community and its reference radiologists

OBJECTIVE: To know the variability in the interpretation (normal/pathological) of posteroanterior view chest radiograph and the associated factors between a medical primary care community and a Gold Standard (GS) from 3 reference radiologists. DESIGN: Crossover study. SETTING: Primary care. Teaching health centers of Elche. METHODS: Interobserver percentage agreement (IPA) and Kappa statistic (K) were used to analyse the interobserver agreement (IA) between the GS and every of the participants in interpretation of 100 radiographs. Intraobserver variability was assessed with a second review. Using uni and multivariant analysis some possibly associated factors were studied. RESULTS: Overall IPA and K were 71.3% (CI 95%: 69.2-73.3) and 0.41 (CI 95%: 0.36-0.46) respectively. Time employed in radiographs reading and time passed after medicine studies finished were independently and significantly associated to higher and lower interobserver agreement results respectively, whereas recent professional experience, permanent job and age were not associated. Professional training is the variable that most explain the inter and intraobserver variability. CONCLUSIONS: Overall IA is acceptable. The IA showed by the participants trained under the MIR system is good but the IA achieved by the rest of participants is not acceptable. It is necessary a training which increase the clinical competence, as it does MIR training.     

Thick film NO2 Sensor

 Thick film technology was used to manufacture a solid-state electrochemical nitrogen dioxide sensor. The prepared sensor has a linear dependence of electromotive force that is based in the NO₂ concentration level. This paper presents discussion on a thick-film sensor that has a much smaller dimension and shorter response time as compared to typical ceramic solid-state electrochemical devices. Received: 26 February 1996/Accepted: 27 June 1996     

浅谈系统稳定及励磁最优控制

最优励磁控制与一般比例励磁调节具有明显的优点,它可提高系统的微动稳定性和微动态稳定功率极限,且可改善系统的动态品质。文章简要推导了最优励磁控制采用二次型目标的控制式,论述了如何利用该控制式采用最优励磁控制提高系统稳定性。     

无线通信技术在沙漠油田安全生产中的应用

介绍无线通信技术在沙漠油田安全生产中的应用。     

模糊模式识别在轨道电路分路不良预警中的应用

针对站内25 Hz相敏轨道电路分路不良问题,通过系统分析,建立轨道电路预警模型,采用模糊模式识别方法实现轨道电路调整电压、现场温湿度以及故障次数的预警,并详细论述了轨道电路模糊模式识别模型的建立,同时给出了预警系统的实现方案;模拟实验及仿真结果表明,模糊模式识别在轨道电路分路不良预警中具有较高的准确性和应用价值,对解决轨道电路分路不良问题提供了有效的技术支持,为轨道电路日常维护和故障的及时发现处理创造了条件.     

基于蚁群优化的WSN能耗均衡链状路由协议

为了从路由技术的角度解决无线传感器网络的能耗问题,综合蚁群优化算法和PEGASIS协议的思想提出了ACO-PEGASIS路由协议;该协议采用蚁群优化算法构建通信链,解决了PEGASIS协议中由于贪婪算法的局部性产生的相邻节点间的长链问题;并在成链过程中综合考虑节点间距离、节点剩余能量等因子,以均衡全网的能量消耗;同时根据距离和能量因素选取链头节点并采用一定措施降低链头重选次数;仿真结果表明,与PEGASIS协议相比,该协议更加有效地均衡了全网的能量消耗,延长了网络的生存周期。     

A case of using the Semantic Interoperability Framework for custom orthopedic implants manufacturing

The efficiency and effectiveness of the daily practice in orthopedic surgery depend on the availability, interoperability and unique access to a wide set of information, related to the patient’s medical record and diagnosis, domain knowledge and available resources and staff. The most important of the tangible resources, needed for the therapeutic or preventive actions are orthopedic implants. In some cases, the implants may be highly complex and customized products, which need to be manufactured (assembled) on basis of the above information in a shortest possible timeframe. In this paper, the case of the custom orthopedic implants manufacturing is described from the perspective of the collaborative enterprising, with special consideration of the interoperability issues of the involved enterprise collaboration. It is shown how the previously developed Semantic Interoperability Framework can be used to improve the efficiency of the manufacturing and other relevant processes.