63 research outputs found
Vascular endothelial growth factor-A165b prevents diabetic neuropathic pain and sensory neuronal degeneration
Diabetic peripheral neuropathy affects up to half of diabetic patients. This neuronal damage leads to sensory disturbances, including allodynia and hyperalgesia. Many growth factors have been suggested as useful treatments for prevention of neurodegeneration, including the vascular endothelial growth factor (VEGF) family. VEGF-A is generated as two alternative splice variant families. The most widely studied isoform, VEGF-A165a is both pro-angiogenic and neuroprotective, but pro-nociceptive and increases vascular permeability in animal models. Streptozotocin (STZ)-induced diabetic rats develop both hyperglycaemia and many of the resulting diabetic complications seen in patients, including peripheral neuropathy. In the present study, we show that the anti-angiogenic VEGF-A splice variant, VEGF-A165b, is also a potential therapeutic for diabetic neuropathy. Seven weeks of VEGF-A165b treatment in diabetic rats reversed enhanced pain behaviour in multiple behavioural paradigms and was neuroprotective, reducing hyperglycaemia-induced activated caspase 3 (AC3) levels in sensory neuronal subsets, epidermal sensory nerve fibre loss and aberrant sciatic nerve morphology. Furthermore, VEGF-A165b inhibited a STZ-induced increase in Evans Blue extravasation in dorsal root ganglia (DRG), saphenous nerve and plantar skin of the hind paw. Increased transient receptor potential ankyrin 1 (TRPA1) channel activity is associated with the onset of diabetic neuropathy. VEGF-A165b also prevented hyperglycaemia-enhanced TRPA1 activity in an in vitro sensory neuronal cell line indicating a novel direct neuronal mechanism that could underlie the anti-nociceptive effect observed in vivo. These results demonstrate that in a model of Type I diabetes VEGF-A165b attenuates altered pain behaviour and prevents neuronal stress, possibly through an effect on TRPA1 activity
Genome-Wide Linkage Analysis of Global Gene Expression in Loin Muscle Tissue Identifies Candidate Genes in Pigs
BACKGROUND: Nearly 6,000 QTL have been reported for 588 different traits in pigs, more than in any other livestock species. However, this effort has translated into only a few confirmed causative variants. A powerful strategy for revealing candidate genes involves expression QTL (eQTL) mapping, where the mRNA abundance of a set of transcripts is used as the response variable for a QTL scan. METHODOLOGY/PRINCIPAL FINDINGS: We utilized a whole genome expression microarray and an F(2) pig resource population to conduct a global eQTL analysis in loin muscle tissue, and compared results to previously inferred phenotypic QTL (pQTL) from the same experimental cross. We found 62 unique eQTL (FDR <10%) and identified 3 gene networks enriched with genes subject to genetic control involved in lipid metabolism, DNA replication, and cell cycle regulation. We observed strong evidence of local regulation (40 out of 59 eQTL with known genomic position) and compared these eQTL to pQTL to help identify potential candidate genes. Among the interesting associations, we found aldo-keto reductase 7A2 (AKR7A2) and thioredoxin domain containing 12 (TXNDC12) eQTL that are part of a network associated with lipid metabolism and in turn overlap with pQTL regions for marbling, % intramuscular fat (% fat) and loin muscle area on Sus scrofa (SSC) chromosome 6. Additionally, we report 13 genomic regions with overlapping eQTL and pQTL involving 14 local eQTL. CONCLUSIONS/SIGNIFICANCE: Results of this analysis provide novel candidate genes for important complex pig phenotypes
Ammonium chloride catalyzed synthesis of novel Schiff bases from spiro[indoline-3,4′-pyran]-3′-carbonitriles and evaluation of their antimicrobial and anti-breast cancer activities
Antibacterial and free radical scavenging activity of a medicinal plant Solanum xanthocarpum
The present study describes the phytochemical profiles, antibacterial, and antioxidant properties of different solvent extracts of Solanum xanthocarpum leaves. Phytochemical analysis results revealed the presence of terpenoids, tannins, steroids, and phenols. Methanolic extract of plant had a maximum quantity of phenol (28.3 ± 2.0 mg) and flavonoids (25.2 ± 1.2 mg) than others. Similarly, the methanolic extract showed excellent antibacterial activity and exhibited the highest inhibitory effect against Pseudomonas aeruginosa (12 ± 0.5 mm), Salmonella typhi (10 ± 0.6 mm), Staphylococcus aureus (9 ± 1.0 mm), and Escherichia coli (7 ± 1.3 mm). The average minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values were reported in the range of 3.2 to 6.9 µg/ml (for MIC) and 6.0 to 14.5 µg/ml (for MBC), respectively. The remarkable antioxidant activity was observed in chloroform and methanol extract on the DPPH radical scavenging activity with the lowest IC50 value of 197.245 μg/ml (chloroform) and 201.04 μg/ml (methanol) and compared with control (ascorbic acid 239.36 μg/ml). GC-MS analysis revealed the presence of six major bioactive compounds as follows; 2,Octylcyclopropene-1-Heptanol (42.81%), Hexadecanoic acid (26.63%), 1-methylene-2b Hydroxymethyl-3,3-Dimethyl-4b-(3Methylbut-2enyl)-C (9.3%), Phytol (7.5%), (1,3,3-Trimethyl-2-Hydroxymethyl-3,3-Dimethyl-4–3-Methylbut-2-Enyl)-C (7.2%). 3,7,11,15-Tetramethyl-2-Hexadecen-1-Ol (6.3%). The FT-IR spectrum reflected the presence of the twelve peaks at the range of 3746.38 cm-1 (O-H stretch alcohols), 3424.18 cm-1 (O-H stretch phenols), 2926.01 cm-1 (C-H stretch alkanes), 2857.55 cm-1 (C-H stretch alkanes), 2084.04 cm-1 (-C = C stretch alkynes), 1595.76 cm-1 (N-H bend primary amines), 1402.49 cm-1 (C-C stretch in ring aromatics) and others. This study suggests S. xanthocarpum as a potential candidature for having better antibacterial and antioxidant property and identified several bioactive compounds by GC-MS analysis
Microbial inhibition, growth of Liþ-doped LAP single crystals and their characterization
The addition of citric acid in the growth solution of LAP found to inhibits the microbial contamination and coloration of the
solution with time exist in the growth of LAP by the conventional slow solvent evaporation technique. The stability study of the
pure and citric acid mixed LAP solution at different temperature shows that the addition of citric acid has the advantage of
extending the durability of the growth solution without coloration and convenience of usage for the growth of high-quality LAP
crystals. Pure and Liþ-doped LAP crystals were grown by slow solvent evaporation technique and are characterized by X-ray
powder diffraction, FTIR, thermal analysis (TGA, DTA) and AC impedance analysis. The presence of Liþ in Liþ-doped LAP was
measured by atomic absorption spectroscopy (AAS). The results suggested that tri-lithium citrate has the characteristics of lithium
doping in LAP crystals and inhibits the microbial growth and coloration
Synthesis methods and electrochemical performance: A theory on the valence disproportionation in LiMyMn2-yO4 (M = Mn, Co) with interalia guiding principles for a photo-chargeable lithium battery
10.1021/jp408127xJournal of Physical Chemistry C1174523547-2355
Influence of metal assisted chemical etching time period on mesoporous structure in as-cut upgraded metallurgical grade silicon for solar cell application
In this work, upgraded metallurgical grade silicon (UMG-Si) wafer was used to fabricate mesoporous nanostructures, as an effective antireflection layer for solar photovoltaic cells. The length of the vertical Si nanostructure (SiNS) arrays was altered by varying the etching time period during metal assisted chemical etching process, using a silver catalyst. The optical, structural, morphological changes and the antireflection properties of Si nanostructures formed on UMG-Siwafer were analysed. SEM and photoluminescence studies indicate that Si nanocrystals are formed on the surface and along the vertical nanowires. The pore size depends on the Ag nanoparticle size distribution. All the samples demonstrated a luminescence band centred around 2.2 eV. From the optical results, samples etched for 45 min show strong absorption in the visible spectrum. The minimum and maximum surface reflectance in the visible region was observed for 15 min and 60 min etched SiNS. Based on the observed results, 15 min etched Si with a uniform porous structure has minimum reflectance across the entire silicon UV–Vis absorption spectrum, making it worth further investigation as a candidate for use as an antireflection layer in silicon based solar cells
Effects of silver catalyst concentration in metal assisted chemical etching of silicon
A systematic investigation is performed to determine the effects of the concentration of silver on metal assisted chemical etching (MaCE) for nanostructure formation mechanisms on silicon as well as their resultant optical properties. Silver nitrate concentrations of 8 mM, 4 mM, 3 mM and 2 mM with hydrogen fluoride were used for the preparation of p-type silicon nanostructures. Experimentally, it is observed that when the catalysis molarity concentration is decreased in the etching processes, it resulted in nanostructures ranging from 140 to 60 nm, respectively over the concentrations investigated. A detailed analysis of the optical properties and structure provided insight into the physics of their formation. In addition, the results show the silicon nanostructures formed black silicon where in the visible region of the spectrum the reflectance dropped by an order of magnitude. The results indicate MaCE is a promising approach to the manufacturing of antireflection coatings on black silicon-based solar photovoltaic cells. MaCE is a simple and scalable approach to enhance the optical absorption of silicon and improve the overall efficiency of the solar cell without adding significantly to the complexity, capital expenditure or cost of production.Peer reviewe
Ambiance-dependent agglomeration and surface-enhanced Raman spectroscopy response of self-assembled silver nanoparticles for plasmonic photovoltaic devices
The agglomeration/dewetting process of thin silver films provides a scalable method of obtaining self-assembled nanoparticles (SANPs) for plasmonics-based thin-film solar photovoltaic (PV) devices. We show the effect of annealing ambiance on silver SANP average size, particle/cluster finite shape, substrate area coverage/particle distribution, and how these physical parameters influence optical properties and surface-enhanced Raman scattering (SERS) responses of SANPs. Statistical analysis performed indicates that generally Ag SANPs processed in the presence of a gas (argon and nitrogen) ambiance tend to have smaller average size particles compared to those processed under vacuum. Optical properties are observed to be highly dependent on particle size, separation distance, and finite shape. The greatest SERS enhancement was observed for the argon-processed samples. There is a correlation between simulation and experimental data that indicate argon-processed AgNPs have a great potential to enhance light coupling when integrated to thin-film PV
Effects of silver catalyst concentration in metal assisted chemical etching of silicon
A systematic investigation is performed to determine the effects of the concentration of silver on metal assisted chemical etching (MaCE) for nanostructure formation mechanisms on silicon as well as their resultant optical properties. Silver nitrate concentrations of 8 mM, 4 mM, 3 mM and 2 mM with hydrogen fluoride were used for the preparation of p-type silicon nanostructures. Experimentally, it is observed that when the catalysis molarity concentration is decreased in the etching processes, it resulted in nanostructures ranging from 140 to 60 nm, respectively over the concentrations investigated. A detailed analysis of the optical properties and structure provided insight into the physics of their formation. In addition, the results show the silicon nanostructures formed black silicon where in the visible region of the spectrum the reflectance dropped by an order of magnitude. The results indicate MaCE is a promising approach to the manufacturing of antireflection coatings on black silicon-based solar photovoltaic cells. MaCE is a simple and scalable approach to enhance the optical absorption of silicon and improve the overall efficiency of the solar cell without adding significantly to the complexity, capital expenditure or cost of production
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