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31.
Osteogenesis imperfecta (OI) is characterized by severe bone deformities, growth retardation and bones that break easily, often from little or no apparent cause. OI is a genetic disorder primarily with defective type I collagen with a wide spectrum of clinical expression. In the more severe cases, it can be diagnosed before birth. Transplantation of mesenchymal stem cells (MSC) has the potential to improve the bone structure and stability, growth and fracture healing. Prenatal and postnatal cell transplantation has been investigated in preclinical and clinical studies of OI and suggests that this procedure is safe and has positive effects. Cell transplantation resulted in improved linear growth, mobility and reduced fracture incidence. However, the effect is transient and for this reason re-transplantation may be needed. So far there is limited experience in this area, and proper studies are required to accurately determine if MSC transplantation is of clinical benefit in the treatment of OI. In this review, we summarize what is currently known in this field. © 2015 John Wiley & Sons, Ltd. 相似文献
32.
Rising demand for product means that the recycling of materials is now more important than ever, saving a lot of energy embedded in materials, thus reducing CO2 emissions. Providing relevant information can raise the recycling efficiency, which is too low at present.A Recycling Information Matrix (RIM) concentrating on Waste Electrical and Electronic Equipment (WEEE) is suggested in order to facilitate and improve materials recycling. Each RIM focuses on a recycling target, and for each type of product a WEEE vector is constructed. The WEEE vector contains nine hexadecimal numbers where core-recycling info is stored.The WEEE vector can provide direct recycling information escorting the product. Another possibility is to individually identify every single product via RFID technology, giving the potential to look for relevant recycling information in databases. This offers the opportunity to add waste-handling information after the product has entered the market. This would be useful, for example, in tracking substances regarded as non-toxic at time of production which might later be proven to be the opposite.This paper is based on study visits at recycling facilities in Sweden and on many student EcoDesign projects including disassembly of consumer products. Research is done on a focused disassembly of dishwashers and on a polymer recycling experiment at a recycling plant for freezers and refrigerators. Possible escort memories are also studied, especially Radio Frequency Identification Devices (RFID). 相似文献
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There must be a change in attitude towards end-of-life products. The view that these products pose a liability must be changed. Secondary material is valuable as raw material. Thus, activities encouraging changes in opinion are important.Two major EU directives guide the recycling process; the Directive of End-of-Life Vehicles (ELV) and the Directive of Waste Electrical and Electronic Equipment (WEEE). Both focus on the input of the recycling system, not on what is coming out of the system.The WEEE Directive is the legislation on the European level that governs the handling and processing of these types of products. The WEEE Directive is not only aimed at stricter handling and reduction of hazardous materials but also encourages EU member states to support technical development in order to facilitate increased recycling.In order to properly address these issues a mind-set, material hygiene, has been introduced. The basic idea is to act, in every life cycle phase of the product, towards highest possible efficiency in recycling. The outcome of useful material is in focus.A study on dishwashers is made with copper outcome as target. The results are based on Swedish conditions but general conclusions can be made. Limited design efforts can raise the outcome of valuable materials, if the recycling process is organized in an optimal manner.A theoretical concept of disassembly structures is used to draw general conclusions on the case study.Increasing product recycling suitability is one side of the problem; another is increasing effectiveness of handling and processing of end-of-life products.The purpose of this paper is to introduce the concept of “material hygiene” and based on that demonstrate a method for grading structural properties in a recycling perspective. The findings presented in this paper are based on a field study in which a number of dishwashers were disassembled and analyzed. 相似文献
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Silvia H. Bonilla Rodrigo L. Guarnetti Cecilia M.V.B. Almeida Biagio F. Giannetti 《Journal of Cleaner Production》2010,18(1):83-91
Bamboo presents physical and mechanical characteristics, which turn it an alternative option for product development, replacing native or reforested wood. The sustainability assessment of a Dendrocalamus Giganteus species plantation in Brazil through the emergy methodology evidences a great weight of renewable (30% sej/sej) and human labour contributions (33% sej/sej). These contributions account for the great interface with environment and to the intensive work, respectively. The transformity value of bamboo production is 2.42E + 04 sej/J. The influence human labour has on the total emergy flow and on indicators is evaluated by taking into account different country locations (Brazil, Australia and China). Thus, a different transformity value for labour is assumed for each country. A ranking based on emergy sustainability index (ESI) values shows that bamboo production in China was the first placed, followed by Brazil and Australia (values of 1.18, 0.50 and 0.09, respectively). The insertion of indirect renewability embedded in labour results in the ranking modification, leading to plantation in Brazil in the first place, followed by the Australian and Chinese ones. The relative position of the bamboo systems is visualized in the ternary diagram expressed in terms of emergy. In an attempt to explore the relationship between sustainability and time, a graphic of ESI vs. global productivity is discussed in terms of a prospective evaluation. Indirect support areas of the bamboo production are calculated as a way to evaluate the sustainability-space relationship. 相似文献
37.
In a warming climate, permafrost is likely to be significantly reduced and eventually disappear from the sub-Arctic region. This will affect people at a range of scales, from locally by slumping of buildings and roads, to globally as melting of permafrost will most likely increase the emissions of the powerful greenhouse gas methane, which will further enhance global warming. In order to predict future changes in permafrost, it is crucial to understand what determines the presence or absence of permafrost under current climate conditions, to assess where permafrost is particularly vulnerable to climate change, and to identify where changes are already occurring. The Tornetr?sk region of northern sub-Arctic Sweden is one area where changes in permafrost have been recorded and where permafrost could be particularly vulnerable to any future climate changes. This paper therefore reviews the various physical, biological, and anthropogenic parameters that determine the presence or absence of permafrost in the Tornetr?sk region under current climate conditions, so that we can gain an understanding of its current vulnerability and potential future responses to climate change. A patchy permafrost distribution as found in the Tornetr?sk region is not random, but a consequence of site-specific factors that control the microclimate and hence the surface and subsurface temperature. It is also a product of past as well as current processes. In sub-Arctic areas such as northern Sweden, it is mainly the physical parameters, e.g., topography, soil type, and climate (in particular snow depth), that determine permafrost distribution. Even though humans have been present in the study area for centuries, their impacts on permafrost distribution can more or less be neglected at the catchment level. Because ongoing climate warming is projected to continue and lead to an increased snow cover, the permafrost in the region will most likely disappear within decades, at least at lower elevations. 相似文献
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Seasonal and long-term variations in the body size of planktonic copepods in the northern Baltic Sea 总被引:2,自引:3,他引:2
Seasonal and long-term variations in the body size of planktonic copepods were studied in the northern Baltic Sea. The influence of temperature, salinity and phytoplankton concentration to the body size of Eurytemora affinis, Acartia bifilosa and Limnocalanus macrurus (Calanoida) was examined at three sea areas, differing in their hydrographical and trophic conditions (an archipelago area and an enclosed bay on the SW coast of Finland in 1992 and at an open sea station in the Gulf of Bothnia in 1991). There was an inverse relationship between copepod body length and temperature, while there was a direct effect of phytoplankton concentration. According to multiple regression analysis, the relative importance of these factors varied according to species, developmental stage and study area. In the archipelago area, copepod body size was mainly determined by temperature, while in the open Gulf of Bothnia, phytoplankton concentration was usually more important. Interannual variation in the summer body length of E. affinis and A. bifilosa was examined using samples collected over 18 years (1967 to 1984) in the archipelago area. In this analysis, the inverse relationship between water temperature and copepod body size disappeared; in E. affinis the average female length correlated positively with summer temperature. We suggest that the length and timing of the study period greatly influence the investigator's view of the factors regulating copepod body size. 相似文献
40.
Diel vertical migration and feeding patterns of Mysis mixta (Crustacea,Mysidacea) in the Baltic Sea 总被引:1,自引:0,他引:1
The extent of the nocturnal vertical migration of Mysis mixta Lilljeborg varied between early July and late October (of 1985 and 1986) in a coastal area of the Baltic Sea. Migration was more restricted in early July and late October. Seasonal changes in surface light levels and transparency were sufficient to explain the observed differences. Mysids avoided light levels above 10-4 lux throughout the study period. Smaller juveniles migrated higher up than larger juveniles and adults. A two-layered distribution with part of the population close to the bottom was observed at night. Zooplankton were more abundant in water layers above the main concentration of mysids. M. mixta fed on phytoplankton, detritus, copepods, cladocerans, rotifers and tintinnids. Diel changes in gut fluorescence indicated a higher intake of phytoplankton at night, but levels were low compared to primarily herbivorous zooplankton. Comparisons of stomach contents of mysids caught at the bottom in the evening and in the water column at night showed a higher ingestion of zooplankton at night and of detritus during the day. Mysids caught at the bottom at night had an intermediate diet. Copepods and cladocerans constituted between 90 and 100% of ingested material by weight in all mysid groups. 相似文献