68 research outputs found
Energy efficient decision fusion for differential space-time block codes in wireless sensor networks
147-156The non-coherent techniques that do not require the channel state information have gained significant interest especially when multiple transmitter and receiver nodes are involved in communication. In this paper, we analyze the energy efficiency of differential and coherent cooperative Multiple-input Multiple-output (MIMO) method using space-time block codes (STBC). We exploit the benefits of the extension of the observation interval of differential STBC to three blocks in Wireless sensor networks (WSNs). We propose an energy efficient decision fusion (EEDF) algorithm in WSNs which utilizes the benefits of Multiple symbol differential detection (MSDD) decision fusion by optimally selecting the ring amplitude of the differential amplitude phase shift keying (DAPSK) constellation. The simulation results show that processing differential multiple symbols provides significant energy saving compared to the conventional two-symbol processing. Furthermore, significant performance gain is achieved for the proposed algorithm compared to 16 DPSK MSDD decision fusions
Effect of compositions in nanostructured lipid carriers (NLC) on skin hydration and occlusion.
Purpose: To study the effects of varying lipid concentrations, lipid and oil ratio, and the addition of propylene glycol and lecithin on the long-term physical stability of nanostructured lipid nanocarriers (NLC), skin hydration, and transepidermal water loss. Methods: The various NLC formulations (A1-A5) were prepared and their particle size, zeta potential, viscosity, and stability were analyzed. The formulations were applied on the forearms of the 20 female volunteers (one forearm of each volunteer was left untreated as a control). The subjects stayed for 30minutes in a conditioned room with their forearms uncovered to let the skin adapt to the temperature (22°C±2°C) and humidity (50%±2%) of the room. Skin hydration and skin occlusion were recorded at day one (before treatment) and day seven (after treatment). Three measurements for skin hydration and skin occlusion were performed in each testing area. Results: NLC formulations with the highest lipid concentration, highest solid lipid concentration, and additional propylene glycol (formulations A1, A2, and A5) showed higher physical stability than other formulations. The addition of propylene glycol into an NLC system helped to reduce the particle size of the NLC and enhanced its long-term physical stability. All the NLC formulations were found to significantly increase skin hydration compared to the untreated controls within 7 days. All NLC formulations exhibited occlusive properties as they reduced the transepidermal water loss within 7 days. This effect was more pronounced with the addition of propylene glycol or lecithin into an NLC formulation, whereby at least 60% reduction in transepidermal water loss was observed. Conclusion: NLCs with high lipid content, solid lipid content, phospholipid, and lecithin are a highly effective cosmetic delivery system for cosmetic topical applications that are designed to boost skin hydration
Phenotypic and genotypic differences between Indian and Scandinavian women with gestational diabetes mellitus
Objective Gestational diabetes mellitus (GDM) is a transient form of diabetes characterized by impaired insulin secretion and action during pregnancy. Population-based differences in prevalence exist which could be explained by phenotypic and genetic differences. The aim of this study was to examine these differences in pregnant women from Punjab, India and Scandinavia. Methods Eighty-five GDM/T2D loci in European and/or Indian populations from previous studies were assessed for association with GDM based on Swedish GDM criteria in 4018 Punjabi Indian and 507 Swedish pregnant women. Selected loci were replicated in Scandinavian cohorts, Radiel (N = 398, Finnish) and STORK/STORK-G (N = 780, Norwegian). Results Punjabi Indian women had higher GDM prevalence, lower insulin secretion and better insulin sensitivity than Swedish women. There were significant frequency differences of GDM/T2D risk alleles between both populations. rs7178572 at HMG20A, previously associated with GDM in South Indian and European women, was replicated in North Indian women. The T2D risk SNP rs11605924 in the CRY2 gene was associated with increased GDM risk in Scandinavian but decreased GDM risk in Punjabi Indian women. No other overlap was seen between GDM loci in both populations. Conclusions Gestational diabetes mellitus is more common in Indian than Swedish women, which partially can be attributed to differences in insulin secretion and action. There was marked heterogeneity in the GDM phenotypes between the populations which could only partially be explained by genetic differences.Peer reviewe
Nanostructured lipid carriers (NLC) for efficient delivery of palm phytonutrients
Palm phytonutrients found in crude palm oil consist of carotenes and tocols as well as other minor components including sterols, squalene, ubiquinones, coenzyme Q10 and phospholipids. Palm phytonutrients contains all the naturally occurring phytonutrients present in crude palm oil, whereas commercially available individual phytonutrients, such as Gold-tri E and Tocomin 50% mainly consist of palm tocotrienols. The encapsulation of palm phytonutrients by nanostructured lipid carriers (NLC) was investigated using Transmission Electron Microscopy. NLC was proven to effectively encapsulate palm phytonutrients in oil droplets. Based on the particle size analysis and rheological study, NLC was found to be the most physically stable delivery system when compared to the macro-emulsion and the nano-emulsion carriers. The long-term chemical stability of the palm phytonutrient using β-carotene as the prototype active in NLC was also determined. The degradation of β-carotene in NLC was lower when compared to the macro-emulsion and the nano-emulsion carriers. The efficacy of NLC as a delivery system and the effect of the addition of lecithin and propylene glycol to the NLC formulation were also studied. The parameters investigated were skin hydration and trans-epidermal water loss (TEWL). NLC with the presence of 1% lecithin and 2% propylene glycol were found to enhance skin hydration and prevent water loss
Antioxidant enzyme activities of human peripheral blood mononuclear cells exposed to trace elements
The trace elements copper, zinc, and selenium are important immune modulators and essential cofactors of the antioxidant enzymes. In the present study, the proliferative effect of human peripheral mononuclear cells (PBMCs) that have been exposed to copper, zinc, and selenium and the corresponding activities of antioxidant enzymes, namely superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase, were determined. Zinc and copper stimulated the PBMC proliferation in a dose-dependent manner within the dose range 25-200 μmol/L. SOD and GPx activities in PBMCs exposed to zinc were inhibited, whereas catalase activity was unaffected. All the three antioxidant enzymes in the cells exposed to copper were inhibited. Selenium exerted more potent inhibition of the cell proliferation while causing stimulation of the antioxidant enzymes at the lowest dose (25 μmol/L) than at the highest dose (200 μmol/L) tested. A significant negative correlation was observed between proliferation and antioxidant enzyme (SOD and GPx) activities in traceelement-exposed PBMC. The present findings substantiate the importance of trace elements as immune modulators and the involvement of enzymatic antioxidant system in the immune cell regulation. © Copyright 2005 by Humana Press Inc. All rights of any nature, whatsoever, reserved
A Comparative Study of the Adsorption Efficiency of the Newly Synthetic Nano Iron Oxide and Commercial Activated Charcoal Towards the Removal of the Nickel(II) Ions
The synthetic nano iron oxide (SNIO) was synthesized by acid base hydrolysis and characterized by the XRD, SEM and EDAX techniques. Batch adsorption experiments were carried out to study the sorption behaviour of SNIO and commercial activated charcoal (CAC) towards Ni(II) ions as a function of initial concentration of the adsorbate, adsorbent dosage, contact time and pH. The adsorption for Ni(II) is found to be better in acidic pH for both SNIO and CAC. The equilibrium adsorption isotherm data have been tested by applying both Freundlich and Langmuir isotherm models. The Separation factor R was found to be between 0 and 1 for both the adsorbent, it clearly indicates the feasibility of adsorption
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