Antioxidant activity of some phenolic constituents from green pepper (Piper nigrum L.) and fresh nutmeg mace (Myristica fragrans)

Antioxidant potential of phenolic compounds from green pepper (Piper nigrum L.) and lignans from fresh mace (Myristica fragrans) were evaluated for their ability to scavenge 1,1′-diphenyl-2-picrylhydrazyl (DPPH) radical, inhibit lipid peroxidation and protect plasmid DNA damage upon exposure to gamma radiation. EC₅₀ values of the major phenolic compounds of green pepper namely, 3,4-dihydroxyphenyl ethanol glucoside, 3,4-dihydroxy-6-(N-ethylamino) benzamide and phenolic acid glycosides were found to be 0.076, 0.27 and 0.12 mg/ml, respectively, suggesting a high radical scavenging activity of these phenolics. These results were further confirmed with cyclic voltammetry. Acetone extract of nutmeg mace and its subsequent TLC isolated fractions constituted mainly of lignans as revealed by GC–MS analysis. The major compounds were tentatively identified from their mass spectral fragmentation pattern. DPPH radical scavenging capacity of the acetone extract as well as its fractions was comparatively lower than that of green pepper phenolics. In contrast, these fractions had a greater ability to inhibit lipid oxidation than phenolics from pepper as revealed by β-carotene–linoleic acid assay. A DNA protecting role of these compounds even at doses as high as 5 kGy further suggested the potential use of green pepper and fresh nutmeg mace and their extracts as a nutraceutical in preventing oxidative damage to cells.     

Nature of the Interlayer Environment in an Organoclay Optimized for the Sequestration of Dibenzo-p-dioxin

A Na-smectite clay (Na-SWy-2) was exchanged with various amounts of dimethyldioctadecylammonium bromide (DODA-Br) up to twice the cation exchange capacity (CEC). The organoclay (DODA-SWy-2) with DODA-Br added at 2 × CEC exhibited a maximum 4.2 nm d-spacing and a 31.4% carbon content, which demonstrates DODA(+) intercalation. DODA-SWy-2 was evaluated as an archetype of commercial products used to sequester hydrophobic contaminants, and the nature of the primarily C18 alkylhydrocarbon-chain interlayer environment was emhasized. Shifts in ν(CH) and CH(2) rocking band positions in DODA-SWy-2-complex FTIR-spectra indicate that DODA C18 chains were more ordered as DODA surface coverage was increased. Differential scanning calorimetry analysis indicated a DODA-SWy-2 gel-to-liquid transition temperature much lower than the melting point of crystalline DODA-Br and similar to that of aqueous DODA-Br vesicles. This suggests that the transition was governed by C18 alkyl tail-tail interactions in the clay interlamellar region. Dibenzo-p-dioxin (DD) sorption from water by DODA-SWy-2 was compared to DD sorption by the geosorbents granular activated carbon (GAC), K-exchanged saponite, and a muck soil. The linear K(l) sorption coefficients (log K(l)) from a linear fit of the sorption isotherms were 4.37 for DODA-SWy-2, 5.55 for GAC, 3.19 for muck soil, and 2.46 for K-saponite. The DD-organic-matter-normalized sorption coefficient (K(om)) was ～2.4 times the octanol-water partition coefficient (K(ow)). This indicates that DD has a higher affinity for the nonpolar interlayer DODA organic phase than for octanol. In contrast, the K(om) for muck soil DD sorption was ～10 times less than K(ow), which reflects the higher polarity of amorphous soil organic matter relative to octanol. Enhanced DD uptake by the DODA-derived lipophilic phase in the organoclay is attributed to the low polarity, "open" C18 alkyl structure due to the physical dimensions of "v-shaped" DODA(+) molecular, and low density of the interlamellar phase (～0.50 g/cm3) density of intercalated DODA(+).     

Bioprospecting traditional Pakistani medicinal plants for potent antioxidants

Antioxidant potential of four methanol extracts from three selected plant species, namely Salvia nubicola (Lamiaceae), Acer oblongifolium (Aceraceae) and Hedera nepalensis (Araliaceae) was measured using assays in aqueous and lipid systems. Antioxidant activities were investigated in aqueous systems by using DPPH radical-scavenging assay, ABTS radical-scavenging assay and DNA protection assay, while antioxidant activity in a lipid system was determined by using the thiobarbituric acid-reactive substances (TBARS) assay. Additionally, the Folin-Ciocalteu method was used to measure total phenolic content. Methanol extracts of leaves and flowers of S. nubicola showed the highest Trolox equivalent (TE) values in the case of the DPPH assay, 2484 ± 4.9 mmol TE/g extract, as well as total phenolic content, 139 ± 0.2 mg gallic acid equivalents/g extract. Three fractions (A-C) of the methanol extract of S. nubicola leaves and flowers were produced by semi-preparative HPLC. Fraction B was found to be the most active in the DPPH radical-scavenging assay and had the highest total phenol content. HPLC-DAD and LC-MS revealed rosmarinic acid in S. nubicola extracts and chlorogenic acid and rutin in H. nepalensis extracts as the main phenolic antioxidants.     

Gonokendra model: a response to “information poverty” in rural areas of Bangladesh

We argue that there is a need to understand impacts of information and communication technologies (ICT) projects in their local context, considering the participants' perspectives at the micro (community) level. Hence, this paper reports on the development and refinement of an extended framework to investigate ICT impact on development in three village areas in the developing country, Bangladesh. Through an interpretive study, we argue that previous studies failed to encapsulate many aspects such as mobility restriction, negative attitude towards female group and religious influences of ICT impact, especially at the micro level. Our extended framework demonstrates that ICT projects can lead to development, but only when social constraints are addressed.     

PACAP and VIP Modulate LPS-Induced Microglial Activation and Trigger Distinct Phenotypic Changes in Murine BV2 Microglial Cells

Pituitary adenylate cyclase-activating polypeptide (PACAP) and vasoactive intestinal peptide (VIP) are two structurally related immunosuppressive peptides. However, the underlying mechanisms through which these peptides regulate microglial activity are not fully understood. Using lipopolysaccharide (LPS) to induce an inflammatory challenge, we tested whether PACAP or VIP differentially affected microglial activation, morphology and cell migration. We found that both peptides attenuated LPS-induced expression of the microglial activation markers Iba1 and iNOS (### p < 0.001), as well as the pro-inflammatory mediators IL-1β, IL-6, Itgam and CD68 (### p < 0.001). In contrast, treatment with PACAP or VIP exerted distinct effects on microglial morphology and migration. PACAP reversed LPS-induced soma enlargement and increased the percentage of small-sized, rounded cells (54.09% vs. 12.05% in LPS-treated cells), whereas VIP promoted a phenotypic shift towards cell subpopulations with mid-sized, spindle-shaped somata (48.41% vs. 31.36% in LPS-treated cells). Additionally, PACAP was more efficient than VIP in restoring LPS-induced impairment of cell migration and the expression of urokinase plasminogen activator (uPA) in BV2 cells compared with VIP. These results suggest that whilst both PACAP and VIP exert similar immunosuppressive effects in activated BV2 microglia, each peptide triggers distinctive shifts towards phenotypes of differing morphologies and with differing migration capacities.     

Metformin Treatment Attenuates Brain Inflammation and Rescues PACAP/VIP Neuropeptide Alterations in Mice Fed a High-Fat Diet

High-fat diet (HFD)-induced comorbid cognitive and behavioural impairments are thought to be the result of persistent low-grade neuroinflammation. Metformin, a first-line medication for the treatment of type-2 diabetes, seems to ameliorate these comorbidities, but the underlying mechanism(s) are not clear. Pituitary adenylate cyclase-activating peptide (PACAP) and vasoactive intestinal peptide (VIP) are neuroprotective peptides endowed with anti-inflammatory properties. Alterations to the PACAP/VIP system could be pivotal during the development of HFD-induced neuroinflammation. To unveil the pathogenic mechanisms underlying HFD-induced neuroinflammation and assess metformin’s therapeutic activities, (1) we determined if HFD-induced proinflammatory activity was present in vulnerable brain regions associated with the development of comorbid behaviors, (2) investigated if the PACAP/VIP system is altered by HFD, and (3) assessed if metformin rescues such diet-induced neurochemical alterations. C57BL/6J male mice were divided into two groups to receive either standard chow (SC) or HFD for 16 weeks. A further HFD group received metformin (HFD + M) (300 mg/kg BW daily for 5 weeks) via oral gavage. Body weight, fasting glucose, and insulin levels were measured. After 16 weeks, the proinflammatory profile, glial activation markers, and changes within the PI3K/AKT intracellular pathway and the PACAP/VIP system were evaluated by real-time qPCR and/or Western blot in the hypothalamus, hippocampus, prefrontal cortex, and amygdala. Our data showed that HFD causes widespread low-grade neuroinflammation and gliosis, with regional-specific differences across brain regions. HFD also diminished phospho-AKT^(Ser473) expression and caused significant disruptions to the PACAP/VIP system. Treatment with metformin attenuated these neuroinflammatory signatures and reversed PI3K/AKT and PACAP/VIP alterations caused by HFD. Altogether, our findings demonstrate that metformin treatment rescues HFD-induced neuroinflammation in vulnerable brain regions, most likely by a mechanism involving the reinstatement of PACAP/VIP system homeostasis. Data also suggests that the PI3K/AKT pathway, at least in part, mediates some of metformin’s beneficial effects.     

Kinetic studies on immobilised lipase esterification of oleic acid and octanol

The present work investigates the reaction kinetics of immobilised lipase esterification of oleic acid and octanol, in a solvent-free system. Lipase from Rhizomucor miehei was immobilised on a hydrophobic support. The initial reaction rate was investigated as a function of octanol concentration and temperature, and the reaction kinetics were described in terms of the Michaelis–Menten mechanism. Evaluating K_m, V_max and k_cat/K_m as a function of temperature, it was found that K_m was minimum and k_cat/K_m was maximum at 40°C while V_max was maximum at 50°C. Furthermore, applying the Ping Pong Bi Bi mechanism yielded good results for this two-substrate system.     

Comparative Analysis of Intercell Interference Mitigation Techniques in LTE-A Network

The performance of long term evolution-advance (LTE-A) depends on different factors such as spectral efficiency, throughput and signal interference to noise ratio (SINR). Interference causes the performance of a network to be grassed to very low level, it directly affects the parameters such as noise interference, receiving diversity and system receiving gain so to mitigate the interference in LTE-A network is very important. Interference occurs in two forms, intra-cell interference and inter-cell interference. Intra-cell interference is removed by orthogonal frequency division multiple access, but the problem of inter-cell interference still exists due to reception of signals from two adjacent base stations at same frequency on user equipment, so coordination is applied between the cells to reduce the interference between the cells. This paper focuses on coordination between the base stations using dynamic cooperative Base Station selection (DCBS). In this paper, SINR, system capacity, minimum and maximum rates of the system are analyzed when coordination is applied between the cells. Three different scenarios are discussed in this paper, which includes coordinated multipoint transmission and reception (COMP), non-COMP and DCBS and then the results of these scenarios are compared.     

Evaluation of rare earth (Yb,La) doped (Sm3Fe5O12) garnet ferrite membrane for LT-SOFC

Rare earth element doping is a popular methodology for improving the electrical and electrochemical properties of materials. Inspired by this ideology, garnet ferrite material Sm₃Fe₅O₁₂ (SFO) doped by rare earth (Yb, La) metal ions to form Sm_3-0.5Yb_0.5Fe₅O₁₂ (SYFO) and Sm_3-0.5La_0·5Fe₅O₁₂ (SLFO). The samples are synthesized by sol gel auto combustion and have been applied as electrolyte membrane for the first time in low temperature solid oxide fuel cell (LT-SOFC). The results indicate that the as-prepared materials have triple charge transport (H⁺/O^?2/e^?) carrier which promotes the hydrogen oxidation reaction (HOR) and oxygen reduction reactions (ORR) in SOFC at triple phase boundary region (TPB). Electrochemical impedance spectroscopy (EIS) reveals that the polarization resistance of SLFO membrane significantly reduces from 0.92 Ω-cm² to 0.45 Ω-cm² and the power output improve from 310 mW/cm² to 650 mW/cm² at 550 °C temperature in comparison with that of SYFO and SFO electrolyte supported cells. UV-vis diffused spectroscopy explains the semiconducting nature of the prepared materials due to the existence of optical bandgap in the semiconductor region. The further investigation also verifies the protonic conduction of SLFO membrane by constructing oxygen ion blocking fuel cell with configuration of Ni-NCAL/BZCY/SLFO/BZCY/Ni-NCAL having 427.94 mW/Cm² fuel cell performance with 1.03 OCV at 550 °C temperature.