334 research outputs found

    Direct Electrochemical Synthesis of Nickel (II) Thiolates and their Coordination Complexes.

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    Metallo organic compounds can be synthesized electrochemically by anodic generation of metal cations by using sacrificial metal anode. Bis-thiolates complexes of Nickel, Ni(SR)2 have been prepared in an H-type cell by electrochemical oxidation of thiols RSH (ethanethiol, 2-propanethiol, 1-butanethiol, 1-pentanethiol and thiophenol) with sacrificial Nickel (Ni) anode and inert Platinum (Pt) cathode in non-aqueous solution of acetonitrile containing tetrabutylammonium chloride  (as supporting electrolyte). On refluxing   with ligand (L)  2,2'-bipyridyl, these thiolates do not form coordination compounds. However, their adducts Ni(SR)2.L have been synthesized electrochemically by adding the ligand to above thiols in solution phase. All these synthesized complexes have been characterized by elemental analysis, infrared spectral data and other physical measurements. All these compounds are in the solid state with excellent yield and associated with high electrochemical efficiency

    Electrochemical Reactions at Sacrificial Electrodes: Electrochemical Synthesis of Aluminium(III) Alkoxides and their Coordination Compounds

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    Electrochemical   reactions of methanol, ethanol, propan-l-ol, butan-1-ol, pentan-1-ol, hexan-1-ol, heptan-1-ol, octan-1-ol, nonan-1-ol and decan-1-ol (ROH) at sacrificial aluminium anode and inert platinum cathode in the presence of tetrabutylammonium chloride as a conductive additive and acetonitrile as solvent yield aluminium(III) alkoxides. On refluxing with ligand (L) {where L = 2,2’-bipyridyl and 1,10-phenanthroline} these alkoxides don’t form coordination compounds. However, the coordination compounds have been prepared by electrolyzing the solution of above alcohols in the presence of ligand (L) at aluminium anode. These products have been characterized by microanalysis, physical measurements and IR spectral studies.General formula conform to M(OR)3 and M(OR)3.L.{where M- Aluminium and L- ligand}.All these reactions proceed with high current efficiencies

    An aerobiological perspective of dust in cage-housed and floor-housed poultry operations

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    The Canadian poultry production industry contributes nearly $10 billion to the Canadian economy and employs nearly 50,000 workers. However, modern poultry facilities are highly contaminated with airborne dust. Although there are many bioaerosols in the poultry barn environment, endotoxin is typically attributed with the negative respiratory symptoms observed in workers. These adverse respiratory symptoms have a higher prevalence in poultry workers compared to workers from other animal confinement buildings. Workers in cage-housed operations compared to floor-housed facilities report a higher prevalence of some respiratory symptoms. We review the current state of knowledge on airborne dust in poultry barns and respiratory dysfunction in poultry workers while highlighting the areas that need further investigation. Our review focuses on the aerobiological pathway of poultry dust including the source and aerosolization of dust and worker exposure and response. Further understanding of the source and aerosolization of dust in poultry operations will aid in the development of management practices to reduce worker exposure and response

    Engineering and Characterization of Human β-defensin-3 and Its Analogues and Microcin J25 Peptides Against \u3cem\u3eMannheimia haemolytica\u3c/em\u3e and Bovine Neutrophils

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    Mannheimia haemolytica-induced bovine respiratory disease causes loss of millions of dollars to Canadian cattle industry. Current antimicrobials are proving to be ineffective and leave residues in meat. Antimicrobial peptides (AMPs) may be effective against M. haemolytica while minimizing the risk of drug residues. Cationic AMPs can kill bacteria through interactions with the anionic bacterial membrane. Human β-Defensin 3 (HBD3) and microcin J25 (MccJ25) are AMPs with potent activity against many Gram-negative bacteria. We tested the microbicidal activity of wild-type HBD3, three HBD3 peptide analogues (28 amino acid, 20AA, and 10AA) derived from the sequence of natural HBD3, and MccJ25 in vitro against M. haemolytica. Three C-terminal analogues of HBD3 with all cysteines replaced with valines were manually synthesized using solid phase peptide synthesis. Since AMPs can act as chemoattractant we tested the chemotactic effect of HBD3, 28AA, 20AA, and 10AA peptides on bovine neutrophils in Boyden chamber. Minimum bactericidal concentration (MBC) assay showed that M. haemolytica was intermediately sensitive to HBD3, 28AA and 20AA analogues with an MBC of 50 µg/mL. The 10AA analogue had MBC 6.3 µg/mL which is likely a result of lower final inoculum size. MccJ25 didn’t have significant bactericidal effect below an MBC \u3c 100 µg/mL. Bovine neutrophils showed chemotaxis towards HBD3 and 20AA peptides (P \u3c 0.05) but not towards 28AA analogue. Co-incubation of neutrophils with any of the peptides did not affect their chemotaxis towards N-formyl-l-methionyl-l-leucyl-phenylalanine (fMLP). The data show that these peptides are effective against M. haemolytica and are chemotactic for neutrophils in vitro

    The effects of temperature difference and compressive force to the electrical characterization of peltier cell for artificial concentrated solar power thermoelectric application / Baljit Singh ... [et al.]

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    Concentrated thermoelectric generating system uses concentrated solar radiations as passive heat source to operate the thermoelectric module for thermoelectricity generation. The pre-perquisite of thermoelectric effect is to provide a temperature difference across the thermoelectric cell by installing active water-cooling device on the opposite side of the heated panel Thermoelectric cells are known to have low energy conversion (3-5%) hence optimizing the parameters associated with the operation of the thermoelectric cells is very important to improve the overall system efficiency. Thermal contact interfacial tests were carried out to determine the optimum compressive stress for greater thermoelectric power generation as well as to avoid cell damage under mechanical compression. In this paper, a series of parametric studies for output power, output current, output voltage and open circuit voltage were conducted indoor on a Peltier-type thermoelectric cell to investigate the thermoelectric performance under different conditions. The aim of this study is to achieve optimum setting prior to the development of the final test rig which will be tested outdoor. The indoor experiments have shown that there is a limit to the overall cooling water flow rate and the compressive force applied to the thermoelectric cells under optimal operation. At the optimal parametric consideration of 11.11 ml/s cooling water flow rate and 245.25 kPa compressive forces, the thermoelectric cell was able to produce output power of 4.19W while operating at temperature difference of94.55°C and efficiency of 2.62% (21.88% of Carnot efficiency)

    Electrochemical enzyme-linked immunosorbent assay (e-ELISA) for parasitic nematode: Ostertagia ostertagi (brown stomach worm) infections in dairy cattle

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    A sensitive electrochemical immunoassay (e-ELISA) has been developed for the detection of the gastrointestinal parasitic nematode Ostertagia ostertagi (brown stomach worm) in infected and control serum samples. An antigen-indirect immunoassay format was employed to detect the presence of O. ostertagi antibodies, coupled with an anti-species monoclonal horseradish peroxidase (HRP) conjugate. ABTS (2,2\u27-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)) and TMB (3,3\u27,5,5\u27-tetramethylbenzidine/hydrogen peroxide) were investigated as both chromogenic visualising reagents for optical ELISA and electroactive substrates for electrochemical ELISA in the HRP catalysed oxidation reaction. Coulometry was applied for the detection of O. ostertagi antibodies (via TMB electrochemistry) and compared with the commercial optical ELISA (ABTS based SVANOVIR® O. ostertagi-Ab ELISA kit). Cost-effective in-house sensors were designed and fabricated using polyester and chemical adhesive materials with the aid of stencil printing and laser machining techniques. The performance of the electrochemical ELISA and sensor was evaluated by investigating redox mediators (ABTS vs. TMB), stop solutions (sodium dodecyl sulfate vs. sulfuric acid) and incubation times (150 min vs. 70 min vs. 25 min). For a total assay incubation time of 70 minutes, the TMB/H2SO4 based e-ELISA was able to differentiate between positive (P) and negative (N) control serum samples, with a P/N70 control ratio 1.6 times higher than that of optical ELISA (TMB/H2SO4 combination) and 2.9 times higher than that of the commercial ELISA kit (ABTS/SDS combination). Furthermore, the e-ELISA approach is quicker and required only 25 min (total incubation time) with even better response (P/N25 = 14.7), which is approximately 4-fold higher than the optical immunoassay (P/N25 = 3.8). The proposed e-ELISA is specific (selective Ab-Ag interactions) and highly sensitive - capable of detecting up to 16-fold dilutions of a positive control serum sample. The electrochemical ELISA approach has the potential for rapid sample screening in a portable, disposable format, contributing to the quest for effective prevention and control of parasitic Ostertagia ostertagi infections in cattle

    Nanomaterials-Based Biosensors for the Detection of Prostate Cancer Biomarkers: Recent Trends and Future Perspective

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    Cancer is among the leading causes of death and an important barrier to improving life expectancy globally. Prostate cancer is the second most common cancer in men worldwide. The detection of biomarkers in body fluids is the key topic for the diagnosis and prognosis of prostate cancer. Despite advances in prostate cancer detection methods, therapeutic agents and new biomarkers, prostate cancer remains a serious challenge. Prostate-specific antigen (PSA) is widely recognized as an important biomarker for the diagnosis of prostate cancer although researchers have also investigated the use of alternative biomarkers. Design and development of novel biosensors for prostate cancer detection has become a hot research area with advances in nanotechnology aiding biosensor development. This article reviews recent achievements and progress that nanomaterials and nanotechnology have made in biomarkers based biosensors for prostate cancer detection and covers: i) PSA-targeted biosensors (immunosensors, aptamer-based, peptide-based and nanopore-based biosensors), ii) sarcosine oxidase-targeted biosensors, iii) other biomarkers based biosensors (prostate cancer antigen 3 (PCA3), vascular endothelial growth factor (VEGF) and prostate-specific membrane antigen (PSMA)) including dual biomarkers based biosensors (PSA-VEGF, PSA-PSMA, PSA-PCA3 and PSA-sarcosine). The aim of this review is to provide insights into how nanomaterials in combination with various biomarkers are now aiding biosensor development in prostate cancer diagnostics

    Analysis and Optimization of Heat Transport for the Purpose of Maximizing the Potential of Solar Ponds in Sustainable Energy Applications

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    Modern solar ponds can be used for power generation, water heating, and even desalinization. Understanding the internal heat transport mechanisms is vital for maximizing their potential use. In-depth discussion of how to analyze heat transfer in solar ponds is provided in this chapter. Heat is transferred effectively in solar ponds by conduction, convection, and radiation. They do this by making salinity gradients, or layers, that absorb and store solar heat. Sunlight is absorbed by the upper layer, while the lower layers provide insulation. Researchers look into heat transfer in solar ponds using analytical, computational, and experimental approaches. Temperature distributions and heat transport rates are modelled mathematically using energy balance equations and fluid dynamics. Flow patterns and convective heat transfer are studied by CFD models. Understanding the efficiency of solar ponds is made easier by experimental observations of temperature profiles and heat flows. The importance of heat transfer analysis in determining the best values for design factors including pond depth, salinity gradient, and insulating materials is highlighted in this chapter. Sustainable potential of solar ponds in diverse energy applications can be unlocked by advancing our understanding of heat transport mechanisms and building accurate models
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