1,663 research outputs found
A QoS-Aware Routing Protocol for Real-time Applications in Wireless Sensor Networks
The paper presents a quality of service aware routing protocol which provides
low latency for high priority packets. Packets are differentiated based on
their priority by applying queuing theory. Low priority packets are transferred
through less energy paths. The sensor nodes interact with the pivot nodes which
in turn communicate with the sink node. This protocol can be applied in
monitoring context aware physical environments for critical applications.Comment: 10 pages. arXiv admin note: text overlap with arXiv:1001.5339 by
other author
Reactive thrombocytosis and pseudohyperkalemia-entities we come across occasionally
AbstractThrombocytosis and hyperkalemia are entities which can have sinister complications in the perioperative period and can be worrisome to the alert anesthesiologist. Hence it is good to be aware of variants which are quite benign and need not lead to delaying of anaesthesia administration. One such case is reported to highlight this fact
A Packet Scheduling Strategy in Sensor Networks with SGMH Protocol
Data communication in sensor networks can have timing constraints like end to
end deadlines. If the deadlines are not met either a catastrophe can happen in
hard real time systems or performance deterioration can occur in soft real time
systems. In real time sensor networks, the recovery of data through
retransmission should be minimized due to the stringent requirements on the
worst case time delays. This paper presents the application of Stop and Go
Multihop protocol (SGMH) at node level in wireless sensor networks for
scheduling and hence to meet the hard real time routing requirements. SGMH is a
distributed multihop packet delivery algorithm. The fractions of the total
available bandwidth on each channel is assigned to several traffic classes by
which the time it takes to traverse each of the hops from the source to the
destination is bounded. It is based on the notion of time frames (Tfr). In
sensor networks packets can have different delay guarantees. Multiple frame
sizes can be assigned for different traffic classes.Comment: 4 pages, 5 figures, IEEE , International Conference ICCCNT 2010,
India, IEEE Explore- 2010, ISBN 978-1-4211-6591, pp 1-4, 30th September 201
Evaluation of human dental stem cell growth characteristics and cellular morphological changes in response to extracellular matrix nanotopography
Objetivo: Nanotopografia e fatores extracelulares solúveis estão presentes nas célulastroncoda polpa dentária Seu efeito na sobrevivência e diferenciação de células-tronco dentárias ainda não foi estabelecido. Nosso objetivo foi analisar os papéis individuais e combinados da nanotopografia e do soro (fatores solúveis) da matriz extracelular (MEC) no crescimento, potencial de diferenciação e características morfológicas das células-tronco da polpa dentária humana. Este estudo avaliou e comparou a resposta detais células-tronco a diferentes estímulos ambientais – nanofibras, soro e meios condicionados. Materiais e métodos: Neste estudo, nanofibras de PLLA fabricadas foram usadas como meio biomimético estrutural in vitro da nanotopografia nativa encontrada na polpa de células-tronco/MEC in vivo. O soro e o meio condicionado foram utilizados como o imitador in vitro dos fatores solúveis aos quais as células-tronco são expostas in vivo. As células-tronco foram cultivadas na presença e ausência de nanofibras de ácido poli-L lático biodegradáveis e soro. As características de crescimento das células-tronco da polpa dentária humana foram avaliadas em termos de viabilidade celular e tempo de duplicação no intervalo de cada passagem. As alterações morfológicas celulares foram estudadas usando microscopia invertida e coloração H&E. Como segunda parte do estudo, as células em todas as condições de cultura foram expostas ao Meio Condicionado para Polpa Dentária (MCPD) por um curto período de 3 dias. As características de crescimento e as alterações morfológicas das células foram avaliadas após a exposição curta ao MCPD. Além disso, a microscopia eletrônica de varredura foi utilizada para o estudo morfológico das células-tronco em nanofibras, expostas aos meios condicionados. As células diferenciadas foram analisadas por TR-PCR quantitativa quanto à expressão neurogênica e odontogênica dos genes RUNX2, osteopontina e β-tubulina III. Resultados: As células-tronco dentárias apresentaram melhor sobrevida e proliferação na presença de nanofibras e soro. A ausência de nanofibras ou soro alterou a sobrevivência e proliferação de células-tronco de forma significativa e indicou diferenciação. Além disso, observou-se que, após a exposição curta ao MCPD, a presença de nanofibras e soro de PLLA favoreceu maior potencial de diferenciação odontogênica e neurogênica, sem alterações morfológicas características da diferenciação terminal. Conclusão: Células-tronco da polpa dentária humana são capazes de detectar sinais geométricos em nanoescala de seu microambiente. Nanotopografia e fatores solúveis da matriz extracelular afetam as células-tronco. Estudos adicionais são essenciais para identificar os principais caminhos que desempenham um papel vital nessas interações.Objective: Nanotopography and soluble extracellular factors are present in the dental stem cell niche in the pulp. Their effect on dental stem cell survival and differentiation is yet to be established. We aimed to analyze the individual and combined roles of extracellular matrix (ECM) nanotopography and serum (soluble factors) on the growth, differentiation potential, and morphological characteristics of the human dental pulp stem cells (hDPSC). This study aimed to evaluate and compare the hDPSC response to different environmental cues – nanofibers, serum, and conditioned media. Materials and methods: In this study, fabricated PLLA nanofibers were used as the in vitro structural biomimetic of the native nanotopography found in the in vivo ECM/stem cell niche. Serum and conditioned media were used as the in vitro mimic of the soluble factors to which stem cells get exposed in vivo. hDPSC were grown in the presence and absence of biodegradablepoly-L-lactic-acid nanofibers and serum. The growth characteristics of hDPSC were assessed in terms of cell viability and doubling time at the interval of every passage. Cellular morphological changes were studied using inverted microscopy and H&E. As the second part of the study, hDPSC in all culture conditions were exposed to Dental Pulp Conditioned Media (DPCM) for a short duration of 3 days. After transient exposure to DPCM, the growth characteristics and the morphological changes of hDPSC were assessed. In addition, scanning electron microscopy was used for the morphological study of hDPSC on nanofibers, exposed to conditioned media. The differentiated cells were analyzed by qRT-PCR for neurogenic and odontogenic expression of RUNX2, osteopontin, and β-tubulin III genes. Results: hDPSC showed better survival and proliferation in the presence of nanofibers and serum. Absence of nanofibers or serum greatly altered stem cell survival and proliferation and also indicated differentiation. In addition, it was observed that after transient exposure to DPCM, the presence of both PLLA nanofiber and serum favoured higher odontogenic and neurogenic differentiation potential, without characteristic morphological changes of terminal differentiation. Conclusion: hDPSC has the ability to sense nanoscale geometric cues from their microenvironment. Nanotopography and soluble factors of the extracellular matrix both affect hDPSC. Further studies are essential to identify the key pathways that play a vital role in such interactions. The hDPSC demonstrated better survival and proliferation in the presence of nanofibers and serum. Absence of nanofibers or serum greatly altered stem cell survival and proliferation and also showed changes indicative of differentiation. The results were compared and analyzed using GraphPad Prism 5 Software. hDPSC possess the ability to sense nanoscale geometric cues from their microenvironment. Nanotopography and soluble factors of the Extracellular matrix together influence the fate of hDPSC. Further studies are essential to identify the key pathways that play a vital role in such interactions
Isolation and characterization of glycosaminoglycans in brain of different species
The uronic acid-containing glycosaminoglycans present in the brains of rat, monkey, chicken, sheep and rabbit were isolated into various fractions by combining the cetyl pyridinium procedure and DEAE-Sephadex column chromatography. The analyses of the fractions show that hyaluronic acid, chondroitin-4-sulphate, chondroitin-6-sulphate, heparan sulphate and a testicular hyaluronidase-resistant galactosamine-containing GAG are present in the brain of all the species studied. Hyaluronic acid is the major GAG (33-41 per cent). Chondroitin-4-sulphate (19-35 per cent), and heparan sulphate (11-19 per cent), are the next prominent GAGs, in all the species except chicken. The results indicate the similarity in the pattern of GAGs in the brain of all the species
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