2,024 research outputs found
The role of GFAP mutation in Alexander disease
Alexaneder disease (AxD) is a primary genetic disorder of astrocyte caused by mutations in the type 111 intermediate filament (IF) glial fibrillary acidic protein (GFAP). The pathological hallmark of this disease is the presence of Rosenthal fibres (RF), ubiquitinated protein aggregates with GFAP being the primary constituent. On the basis of age at onset, the disease has been divided into three subtypes: infantile, juvenile and adult. Whilst one of the common mutations R416W is reported in AxD with a wide range in disease severity and age of onset, the mechanisms by which this mutation leads to AxD remain unknown. To investigate the role of mutated protein in the disease process, I have developed a cell model system in which the expression of GFAP can be regulated by doxycycline. Expression of R416W GFAP leads to aggregate formation, which increases small heat shock protein (sHSP) expression, activates stress-activated protein kinase (SAPK) pathways and partially impairs proteosome function. This is accompanied by the sequestration of sHSPs and activated SAPK into GFAP-containing aggregates, which make cells more susceptible to stress. However, R416W mutation was found to not always disrupt the endogenous Ifs, but to incorporate into GFAP networks when expressed at low levels. The potential functional impact of incorporating low level of the disease-causing GFAP mutant into the pre-exiting GFAP networks is that cells respond poorly to stressful conditions. These data provide direct evidence to suggest that astrocyte dysfunction play a key role in the development of AxD and stress is likely to have the most influence on the presence and progression of the disease
Collimated directional emission from a peanut-shaped microresonator
Collimated directional emission is essentially required an asymmetric
resonant cavity. In this paper, we theoretically investigate a type of
peanut-shaped microcavity which can support highly directional emission with
the emission divergence as small as 2.5o. The mechanism of the collimated
emission is explained with the short-term ray trajectory and the intuitive lens
model in detail. Wave simulation also confirms these results. This extremely
narrow divergence of the emission holds a great potential in highly collimated
lasing from on-chip microcavities
The Key Successful Factors of Internet Business: The Study of Online Bookshop
Electronic commerce is viewed as a more and more important issue for the rapid growth of online commercial activities. The books, having the properties of numerous categories, low unit price, and the convenience of delivering, have become the major products on line. So the online bookshops are appropriate for study to find out the key successful factors of Internet business. We first conduct twice Delphi to confirm several factors that are important to success in Internet business and there are 32 factors to be chosen. We then calculate the relative weigh of each factor with the Analytic Hierarchy Process (AHP) and select 14 factors having the highest weight to be the key successful factors of Internet business. These 14 factors in order of weight include the ability of managing the business change, filling the Place with Entrepreneurs and growing with them, the ability of managing the customer relationship, targeting the right customers, the price can react to market quickly, building the knowledge management systems, excellent sever ice after payment, building distribution center to develop unbeatable logistics, the ability of managing the cost, offering Great Value, the ability of marketing by database, building the goodwill and brand image, getting the trust of virtual community and maintain it continually, and the ability of developing the technology
Building Ubiquitous Computing Environment by Using RFID in Aircraft MRO Process
The implementation of RFID had aroused discussion in every area. Experts believe that the emergence of RFID will cause another business revolution. Many industries had deployed RFID, like aviation industry, in which RFID is used in maintenance materials and baggage management. This paper discusses the implementation of RFID in MRO process and the building of a ubiquitous computing environment. We believe that our proposal has three merits to MRO (1) anti-counterfeit parts (2) MRO liability (3) efficient and effective inspection. The architecture can address the competition pressure that aviation industry faces and consequently enhance competition advantages
Salvia miltiorrhiza aqueous root extract plays an important role in improving locomotor activity in rats with spinal cord injury
Purpose: To investigate the activity of the aqueous root extract of Salvia miltiorrhiza (S. miltiorrhiza) (Lamiaceae), collected from Anhui Province, China, for the treatment of spinal cord injury (SCI) in Sprague-Dawley (SD) rats.Methods: In total, 30 adult rats were selected and divided into three groups; normal control, untreated and treated. Aqueous root extract of S. miltiorrhiza was introduced intraperitoneally to the treated group. Basso, Beattie and Bresnahan rating scale (BBB) was used to evaluate improvement in locomotor activity after SCI. Total RNA was extracted from tissue sections using Sepasol (NacalaiTesque) and RNA samples were reverse-transcribed using M-MLV reverse transcriptase. BioSense SC-810 Gel Documentation System and Gel-Pro 3.1 software were employed for the analysis of band intensity.Results: A significant reduction in SCI cavity area was observed in the S. miltiorrhiza extract-treated group, relative to the untreated group, after 11 days (0.10 ± 0.05 mm2 treated vs. 0.30 ± 0.01 mm2 untreated). Treatment with root extract also improved the BBB scores; the treated group scored 15, compared to a score of 8 for the untreated group. In addition, the degradation of neurons at the site of injury in the spinal cord was reduced in the treated group compared to the untreated group. Treatment with S. miltiorrhiza aqueous root extract also significantly increased the expression of platelet-derived growth factor-B (PDGF-B) mRNA (p < 0.01).Conclusion: These data suggest that, in addition to other pharmacological activities, S. miltiorrhiza extract has therapeutic potential for the treatment of neuronal degeneration following SCI.Keywords: Salvia Miltiorrhiza, Neurons, Spinal cord injury, Locomotor capacity, Platelet-derived growth factor-B, Basso, Beattie and Bresnahan rating scal
- …