21 research outputs found
Energy Efficient Fog Servers for Internet of Things Information Piece Delivery (IoTIPD) in a Smart City Vehicular Environment
Smart cities are promising solution for providing efficient services to the citizens with the use of Information and Communication Technologies. City automation has become essential concept for improving the quality of the citizens' lives, which gives rise to smart cities. Fog computing for Internet of Things (IoT) is considered recently an essential paradigm in smart city scenarios. In this work, we propose energy efficient Fog Servers (FSs), which delivers the information data to the mobile users (in the vehicle). We introduced the concept of energy efficiency through the judicious distribution of non-renewable or/and renewable energy to the FS, which improves outage (and dropping probability. As a first step, we optimise the locations of the FSs for IoT Information Piece Delivery (IoTPD) in a smart city vehicular environment with dropping less than 5%. Then, we maximised the energy savings by pushing dropping to a certain level (5%). To improve the dropping, the available renewable (wind) grid energy is optimally allocated to each FS. This, in turn, also reduces carbon footprint
Load Adaptive Caching Points for a Content Distribution Network
The unprecedented growth in content demand on smartphones has significantly increased the energy consumption of current cellular and backbone networks. Apart from achieving stringent carbon footprint targets, provisioning high data rates to city vehicular users while maintaining quality of service (QoS) remains a serious challenge. In previous work, to support content delivery at high data rates, the number and locations of caching points (CPs) within a content distribution network (CDN) were optimized while reducing the operational energy consumption compared to typical cellular networks. Further reduction in energy consumption may be possible through sleep cycles, which reduces transmission energy consumption. However, sleep cycles degrade the quality of service. Therefore, in this paper, we propose a novel load adaptation technique for a CP which not only enhances content download rate but also reduces transmission energy consumption through random sleep cycles. Unlike a non-load adaptive (deterministic) CP, the performance results reveal that the load adaptive CP achieves considerably lower average piece delay (approximately 60% on average during the day), leveraging the introduction of random sleep cycles to save transmission energy. The proposed CP saves up to 84% transmission energy during off-peak hours and 33% during the whole day while fulfilling content demand in a city vehicular environment
Sub-micron moulding topological mass transport regimes in angled vortex fluidic flow
Shear stress in dynamic thin films, as in vortex fluidics, can be harnessed for generating non-equilibrium conditions, but the nature of the fluid flow is not understood. A rapidly rotating inclined tube in the vortex fluidic device (VFD) imparts shear stress (mechanical energy) into a thin film of liquid, depending on the physical characteristics of the liquid and rotational speed,ω, tilt angle,θ, and diameter of the tube. Through understanding that the fluid exhibits resonance behaviours from the confining boundaries of the glass surface and the meniscus that determines the liquid film thickness, we have established specific topological mass transport regimes. These topologies have been established through materials processing, as spinning top flow normal to the surface of the tube, double-helical flow across the thin film, and spicular flow, a transitional region where both effects contribute. The manifestation of mass transport patterns within the film have been observed by monitoring the mixing time, temperature profile, and film thickness against increasing rotational speed,ω. In addition, these flow patterns have unique signatures that enable the morphology of nanomaterials processed in the VFD to be predicted, for example in reversible scrolling and crumbling graphene oxide sheets. Shear-stress induced recrystallisation, crystallisation and polymerisation, at different rotational speeds, provide moulds of high-shear topologies, as ‘positive’ and ‘negative’ spicular flow behaviour. ‘Molecular drilling’ of holes in a thin film of polysulfone demonstrate spatial arrangement of double-helices. The grand sum of the different behavioural regimes is a general fluid flow model that accounts for all processing in the VFD at an optimal tilt angle of 45°, and provides a new concept in the fabrication of novel nanomaterials and controlling the organisation of matter
Vortex fluidic induced mass transfer across immiscible phases
Mixing immiscible liquids typically requires the use of auxiliary substances including phase transfer catalysts, microgels, surfactants, complex polymers and nano-particles and/or micromixers. Centrifugally separated immiscible liquids of different densities in a 45° tilted rotating tube offer scope for avoiding their use. Micron to submicron size topological flow regimes in the thin films induce high inter-phase mass transfer depending on the nature of the two liquids. A hemispherical base tube creates a Coriolis force as a ‘spinning top’ (ST) topological fluid flow in the less dense liquid which penetrates the denser layer of liquid, delivering liquid from the upper layer through the lower layer to the surface of the tube with the thickness of the layers determined using neutron imaging. Similarly, double helical (DH) topological flow in the less dense liquid, arising from Faraday wave eddy currents twisted by Coriolis forces, impact through the less dense liquid onto the surface of the tube. The lateral dimensions of these topological flows have been determined using ‘molecular drilling’ impacting on a thin layer of polysulfone on the surface of the tube and self-assembly of nanoparticles at the interface of the two liquids. At high rotation speeds, DH flow also occurs in the denser layer, with a critical rotational speed reached resulting in rapid phase demixing of preformed emulsions of two immiscible liquids. ST flow is perturbed relative to double helical flow by changing the shape of the base of the tube while maintaining high mass transfer between phases as demonstrated by circumventing the need for phase transfer catalysts. The findings presented here have implications for overcoming mass transfer limitations at interfaces of liquids, and provide new methods for extractions and separation science, and avoiding the formation of emulsions
The effects of mutant Ras proteins on the cell signalome
The genetic alterations in cancer cells are tightly linked to signaling pathway dysregulation. Ras is a key molecule that controls several tumorigenesis-related processes, and mutations in RAS genes often lead to unbiased intensification of signaling networks that fuel cancer progression. In this article, we review recent studies that describe mutant Ras-regulated signaling routes and their cross-talk. In addition to the two main Ras-driven signaling pathways, i.e., the RAF/MEK/ERK and PI3K/AKT/mTOR pathways, we have also collected emerging data showing the importance of Ras in other signaling pathways, including the RAC/PAK, RalGDS/Ral, and PKC/PLC signaling pathways. Moreover, microRNA-regulated Ras-associated signaling pathways are also discussed to highlight the importance of Ras regulation in cancer. Finally, emerging data show that the signal alterations in specific cell types, such as cancer stem cells, could promote cancer development. Therefore, we also cover the up-to-date findings related to Ras-regulated signal transduction in cancer stem cells. © 2020, The Author(s)
Continuous flow vortex fluidic transformation of kombucha cellulose into more compact and crystalline fibers
A chemical-free and scalable novel route for generating more compact and crystalline cellulose from cellulosic biofilms formed at the air-water interface as an otherwise waste byproduct from the kombucha tea beverage fermentation industry has been developed. This involves processing the byproduct by treatment with aqueous 1 M NaOH at 50 °C and then 1% glacial acetic acid followed by washing with distilled water until the pH of the washing water is 7, followed by continuous flow processing in the vortex fluidic device (VFD). This thin-film microfluidic platform houses a 20 mm outside diameter and 17.5 mm inside diameter quartz tube with a hemispherical base. The induced high shear mechanical energy arising from the topological fluid flows within the thin film when the tube is tilted at θ +45° and spun at ω 6k rpm converts the kombucha cellulose to smaller fiber diameters ∼70 nm cf. ∼127 nm preVFD processing. The material is characterized using dynamic light scattering, scanning electron microscopy, atomic force microscopy, X-ray diffraction, thermogravimetric analysis/differential scanning calorimetry, Fourier transform infrared, and Brunauer-Emmett-Teller. The modification of the cellulose is understood mechanistically by the high shear topological fluid flow from the Coriolis force from the base of the tube, forcing the individual cellulose polymer strands together in an ordered array. Such transient localized high shear flow associated with high temperatures and pressures over the fibers on the surface of the tube force the backbone long cellulose strands together resulting in increased crystallinity. The findings lay the foundation for transforming a byproduct from kombucha tea beverage fermentation into unique material for other applications
Retention and Release of Commercial and Purified Phosphonate Scale Inhibitors on Carbonate Substrate
This paper describes a study of the interactions of phosphonate scale inhibitor with carbonate substrate. Much previous work has appeared on this topic, but here we present results which attempt to address some gaps identified in previous studies of this subject. The experimental programme focused on three main areas: (i) static adsorption/ compatibility analysis of phosphonate scale inhibitor at both 95°C and room temperature (RT). Static tests revealed that SI retention mechanisms are significantly more active at elevated temperatures compared to RT conditions, where only minimal adsorption was observed. At RT conditions with initial pHo = 4, while calcite dissolution occurs and Ca2+ may interact with SI, the formation of precipitate is minimal. Under these conditions, SI concentration primarily governs pH behaviour. These experimental results provided validation data for computational modelling work, which is presented in a separate study [1]. And: (ii) precipitation and re-dissolution tests of SI-Ca2+ complexes which were conducted across a temperature range of 20-95°C, with a subsequent larger-scale test at 95°C. For systems with high [Ca2+], the smaller-scale experiments yielded similar masses of precipitate (post-filtration and oven-drying) across all temperatures. Complex stoichiometry was determined using two methods: direct analysis of re-dissolved precipitates in distilled water/HCl, and indirect measurement of Δ[Ca] and Δ[SI] from supernatant solutions, both using Inductively Coupled Plasma - Optical Emission Spectroscopy (ICP-OES). The stoichiometric analyses revealed that excess [Ca2+] and initial pH of 8.5, rather than temperature, governed the reaction, resulting in near maximum possible complexation between Ca2+ and DETPMP in solution. The precipitates were characterized using ESEM-EDX and thermogravimetric analysis (TGA). ESEM-EDX surface imaging and compositional analysis demonstrated amorphous structures across all temperature conditions, while TGA results showed decreasing water content with increasing preparation temperature. Finally, (iii) Purified SIs obtained at 95°C were used to examine how the removal of phosphorus-containing impurities affects inhibition and adsorption performance. A series of inhibition efficiency (IE) and static adsorption experiments were conducted. The precipitated and redissolved DETPMP samples were evaluated against unmodified commercial DETPMP. Their effectiveness in preventing BaSO4 precipitation through Ba2+ interaction was assessed by measuring Δ[Ba2+] before and after SI addition to the brines using ICP analysis. Results demonstrated that purified materials exhibited similar barium sulphate inhibition efficiency to commercial products, indicating that impurities did not significantly influence the inhibition process. Comparative adsorption studies revealed higher apparent adsorption values for purified DETPMP, attributed to impurities in commercial products being measured as active DETPMP concentrations despite not participating in adsorption. It is shown how this can be easily corrected and accounted for in our results
Effects of Different Concentrations of Opium on the Secretion of Interleukin-6, Interferon-γ and Transforming Growth Factor Beta Cytokines from Jurkat Cells
BACKGROUND:
The risk of infectious, autoimmune and immunodeficiency diseases and cancers rise in opioid addicts due to changes in innate and acquired immune responses. Three types of opioid receptors (К-δ-μ) are expressed on the surface of lymphocytes and mononuclear phagocytes. The present study was designed to examine the effects of different concentrations of opium on the secretion of some cytokines produced by lymphocyte cells.
METHODS:
Jurkat cells were exposed to different concentrations of opium for periods of 6, 24 and 72 h in cell culture medium. The amount of interleukin-6 (IL-6), interferon-γ (IFN-γ) and transforming growth factor-b (TGF-β) were then measured using enzyme-linked immunosorbent assay (ELISA) method.
FINDINGS:
The results showed that opium increases the secretion of IL-6 in different concentration of opium in 6 h. The amount of IFN-γ decreased in 6 h and increased in 24 h significantly compared with control. On the other hand, opium had an inhibitory effect on the TGF-β secretion in 6, 24 and 72 h.
CONCLUSION:
Overall, the study showed that opium stimulates pro-inflammatory and suppressed anti-inflammatory cytokine secretion in Jurkat cells. This may account for the negative effect of opium on the immune system leading to chronic inflammation and a base for many disorders in opium addicts
Autophagy and the peroxisome proliferator-activated receptor signaling pathway: A molecular ballet in lipid metabolism and homeostasis
Lipids, which are indispensable for cellular architecture and energy storage, predominantly consist of triglycerides (TGs), phospholipids, cholesterol, and their derivatives. These hydrophobic entities are housed within dynamic lipid droplets (LDs), which expand and contract in response to nutrient availability. Historically perceived as a cellular waste disposal mechanism, autophagy has now been recognized as a crucial regulator of metabolism. Within this framework, lipophagy, the selective degradation of LDs, plays a fundamental role in maintaining lipid homeostasis. Dysregulated lipid metabolism and autophagy are frequently associated with metabolic disorders such as obesity and atherosclerosis. In this context, peroxisome proliferator-activated receptors (PPARs), particularly PPAR-gamma, serve as intracellular lipid sensors and master regulators of gene expression. Their regulatory influence extends to both autophagy and lipid metabolism, indicating a complex interplay between these processes. This review explores the hypothesis that PPARs may directly modulate autophagy within the realm of lipid metabolism, thereby contributing to the pathogenesis of metabolic diseases. By elucidating the underlying molecular mechanisms, we aim to provide a comprehensive understanding of the intricate regulatory network that connects PPARs, autophagy, and lipid homeostasis. The crosstalk between PPARs and other signaling pathways underscores the complexity of their regulatory functions and the potential for therapeutic interventions targeting these pathways. The intricate relationships among PPARs, autophagy, and lipid metabolism represent a pivotal area of research with significant implications for understanding and treating metabolic disorders
