The Experts below are selected from a list of 12801 Experts worldwide ranked by ideXlab platform
Chris D. Geddes - One of the best experts on this subject based on the ideXlab platform.
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highly sensitive quantitation of human serum albumin in clinical samples for hypoproteinemia using metal enhanced fluorescence
Journal of Fluorescence, 2013Co-Authors: Yongxia Zhang, Buddha Mali, Caroleann Aitken, Chris D. GeddesAbstract:In this paper, we have explored metal-enhanced fluorescence (MEF) of the Human serum albumin indicators: Albumin Blue 580, Merocyanine 540 and Bromophenol Blue in close proximity to Silver Nano-particles, SiFs, from both buffered and clinical samples. The photostability of the Albumin Blue 580 is shown to be much more prolonged from the SiFs as compared to glass (a control sample), potentially allowing for longer detection times to further improve assay statistics. Our findings suggest the widespread use of Nanoparticulate SiFs surfaces for the enhanced detection of HSA, particularly for Hypoproteinemia, where an enhanced assay performance at low protein abundance is required.
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metal enhanced fluorescence of the fluorescent brightening agent tinopal cbx near Silver island film
Dyes and Pigments, 2011Co-Authors: Hirdyesh Mishra, Yongxia Zhang, Chris D. GeddesAbstract:Abstract Metal-enhanced fluorescence (MEF) studies of the optical brightener Tinopal-CBS (4,4′- distyrylbiphenyl sulfonic sodium salt) have been undertaken using steady-state and time resolved fluorescence measurements on Silver island films (SiFs) deposited on glass slides and Silver Nano-particles adsorbed onto cellulose based filter paper. Nearly a 4.5 fold enhancement in fluorescence intensity is observed from both SiFs and Nano-particle deposited cellulose filter paper. In addition an enhanced photostability and decrease in decay time is also observed on SiFs. These results are consistent with two distinct mechanisms of MEF, firstly coupling and transferring of the excited states energies of fluorophores to surface plasmons in the Silver island deposited glass films, and secondly, an electric field enhancement effect, which facilitates enhanced absorption of the fluorophores. Our findings reveal significant benefits of enhanced luminescence and prolonged photostability of Tinopal CBS. As such, Plasmon-tinopal constructs offer new material opportunities as well as multifarious applications in the life sciences.
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metal enhanced fluorescence based calcium detection greater than 100 fold increase in signal noise using fluo 3 or fluo 4 and Silver Nanostructures
Sensors and Actuators B-chemical, 2011Co-Authors: Nina Bondre, Yongxia Zhang, Chris D. GeddesAbstract:Abstract In this paper we describe metal-enhanced fluorescence (MEF) of the Ca 2+ indicators: Fluo-3 and Fluo-4 in close proximity to Silver Nano-particles, SiFs. When the concentration of Ca 2+ increases, the MEF enhancement factor decreases, which is consistent with our previous findings that the greatest fluorescence enhancements occur for fluorophores with the lowest free-space quantum yield. Over 100-fold enhanced fluorescence intensities (signal/noise) were observed. In addition, the photostability of the fluorophore (Fluo-3) is much more prolonged from the SIFs as compared to glass (a control sample). Our findings strongly suggest the widespread use and the general approach of Nanoparticulate SiFs surfaces for the enhanced detection of both intra and extra-cellular calcium and indeed other analytes of interest.
Vishnu Kiran Manam - One of the best experts on this subject based on the ideXlab platform.
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in vitro cytotoxic activity of Silver Nano particle biosynthesized from colpomenia sinuosa and halymenia poryphyroides using dla and eac cell lines
Social Science Research Network, 2014Co-Authors: Vishnu Kiran ManamAbstract:This study was conducted to investigate the invitro cytotoxic activity of Silver Nano particles biosynthesized from Colpomenia sinuosa and Halymenia poryphyroides using DLA and EAC cell lines by tryphan blue dye exclusion technique and MTT assay using Mouse L929 cell lines (Lungs fibroblast). The results of the trypan blue dye exclusion assay indicates that the Silver Nano particles biosynthesized from Colpomenia sinuosa and Halymenia poryphyroides inhibits the growth of DLA and EAC cell lines in a dose dependent manner against the standard drug Curcumin where the Silver Nano particle biosynthesized from Colpomenia sinuosa showed 61.57 % and Silver Nano particle biosynthesized from Halymenia poryphyroides showed 89.36 % in DLA cell line similarly the Silver Nano particle biosynthesized from Colpomenia sinuosa showed 81.96 % and Silver Nano particle biosynthesized from Halymenia poryphyroides 91.45 % in EAC cell line. The results of the MTT assay indicated the Silver Nano particles biosynthesized from Colpomenia sinuosa and Halymenia poryphyroides significantly inhibited the proliferation of L929 cells in dose dependent manner where the Silver Nano particle biosynthesized from Colpomenia sinuosa showed 37.06 % and Silver Nano particle biosynthesized from Halymenia poryphyroides showed 100 % against the standard drug Curcumin.
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invitro antioxidant activity of Silver Nano particles from colpomenia sinuosa and halymenia poryphyroides
Social Science Research Network, 2014Co-Authors: Vishnu Kiran Manam, S MurugesanAbstract:This study was conducted to investigate the in-vitro antioxidant activities of Silver Nano particles biosynthesized from Colpomenia sinuosa and Halymenia poryphyroides. The free radical scavenging activity of the extracts was measured by DPPH and ABTS and the antioxidant potential were compared with commercial antioxidants, such as Butylated Hydroxy Toulene (BHT) and L- ascorbic acid. The antioxidant activity of experimental algae showed a dose dependent increase when compared to commercial antioxidants. Spectrophotometric determination of the active compounds revealed that the antioxidant activity might be attributed to algal contents of carotenoids, free phenols and fatty acids.
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biosynthesis of Silver Nanoparticles from marine alga colpomenia sinuosa and its antibacterial efficacy
Social Science Research Network, 2014Co-Authors: Vishnu Kiran Manam, S MurugesanAbstract:Silver Nano particles are known to be good antibiotic agents. In this study biosynthesis of Silver (Ag) Nano particles of marine alga Colpomenia sinuosa were obtained by green synthesis method and their efficacy was studied against Gram-positive and Gram-negative bacteria. The efficacy was performed using Kirby Bauer Method and MIC, MBC were also determined. The extra cellular mechanism of Silver Nano particle formation was characterized by UV-vis spectroscopy, Fourier Transform Infrared (FT-IR) Spectroscopy-ray Diffraction (XRD), and Scanning Electron Microscopic (SEM) study showed the formation of Silver Nano particle in the range of 54-65 nm in size. Silver Nanoparticles showed greater efficacy towards Gram-positive and Gram-negative microorganisms compared to the standard antibiotics.
Qi Wang - One of the best experts on this subject based on the ideXlab platform.
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in situ synthesis of Silver Nanoparticles bacterial cellulose composites for slow released antimicrobial wound dressing
Carbohydrate Polymers, 2014Co-Authors: Jian Wu, Yudong Zheng, Wenhui Song, Jiabin Luan, Zhigu Wu, Xiaohua Chen, Qi WangAbstract:Bacterial cellulose has attracted increasing attention as a novel wound dressing material, but it has no antimicrobial activity, which is one of critical skin-barrier functions in wound healing. To overcome such deficiency, we developed a novel method to synthesize and impregnate Silver Nanoparticles on to bacterial cellulose Nanofibres (AgNP-BC). Uniform spherical Silver Nano-particles (10-30 nm) were generated and self-assembled on the surface of BC Nano-fibers, forming a stable and evenly distributed Ag Nanoparticles coated BC Nanofiber. Such hybrid Nanostructure prevented Ag Nanoparticles from dropping off BC network and thus minimized the toxicity of Nanoparticles. Regardless the slow Ag+ release, AgNP-BC still exhibited significant antibacterial activities with more than 99% reductions in Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. Moreover, AgNP-BC allowed attachment and growth of epidermal cells with no cytotoxicity emerged. The results demonstrated that AgNP-BC could reduce inflammation and promote wound healing. © 2013 Elsevier Ltd.
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in situ synthesis of Silver Nanoparticles bacterial cellulose composites for slow released antimicrobial wound dressing
Carbohydrate Polymers, 2014Co-Authors: Yudong Zheng, Wenhui Song, Jiabin Luan, Xiaohua Chen, Qi Wang, Xiaoxiao Wen, Shaolin GuoAbstract:Bacterial cellulose has attracted increasing attention as a novel wound dressing material, but it has no antimicrobial activity, which is one of critical skin-barrier functions in wound healing. To overcome such deficiency, we developed a novel method to synthesize and impregnate Silver Nanoparticles on to bacterial cellulose Nanofibres (AgNP-BC). Uniform spherical Silver Nano-particles (10-30 nm) were generated and self-assembled on the surface of BC Nano-fibers, forming a stable and evenly distributed Ag Nanoparticles coated BC Nanofiber. Such hybrid Nanostructure prevented Ag Nanoparticles from dropping off BC network and thus minimized the toxicity of Nanoparticles. Regardless the slow Ag(+) release, AgNP-BC still exhibited significant antibacterial activities with more than 99% reductions in Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. Moreover, AgNP-BC allowed attachment and growth of epidermal cells with no cytotoxicity emerged. The results demonstrated that AgNP-BC could reduce inflammation and promote wound healing.
Josefa Barreromoreno - One of the best experts on this subject based on the ideXlab platform.
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size and mass determination of Silver Nanoparticles in an aqueous matrix using asymmetric flow field flow fractionation coupled to inductively coupled plasma mass spectrometer and ultraviolet visible detectors
Journal of Chromatography A, 2013Co-Authors: Otmar Geiss, Claudia Cascio, Douglas Gilliland, Fabio Franchini, Josefa BarreromorenoAbstract:The powerful antibacterial properties of engineered Silver Nanoparticles (AgNPs) have, in recent years, led to a great increase in their use in consumer products such as textiles and personal care products offers. This widespread and often indiscriminate use of Nano-Silver is inevitably increasing the probability that such materials be accidentally or deliberately lost into the environment. Once present in the environment the normally useful antibacterial properties of the Silver may instead become a potential hazard to both man and the environment. In the face of such concerns it therefore desirable to develop easy, reliable and sensitive analytical methods for the determination of Nano-sized Silver in various matrices. This paper describes a method for the simultaneous determination of particles-size and mass-concentration of citrate-stabilized Silver Nano-particles in aqueous matrices by asymmetric flow field flow fractionation coupled to an ICP-mass spectrometer and UV/vis detector. In particular, this work has evaluated the use of pre-channel injections of mono-dispersed Silver Nano-particles as a means of accurate size and mass-calibration. The suitability of the method as a means to generate accurate and reliable results was verified by determination of parameters such as precision under repeatability conditions, linearity, accuracy, recovery and analytical sensitivity.
Shungwen Kang - One of the best experts on this subject based on the ideXlab platform.
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experimental investigation of Nanofluids on sintered heat pipe thermal performance
Applied Thermal Engineering, 2009Co-Authors: Shungwen Kang, Shenghong Tsai, Chiaching HuangAbstract:Abstract Dilute dispersion of Silver Nano-particles in pure water was employed as the working fluid for conventional 1 mm wick-thickness sintered circular heat pipe. The Nanofluid used in present study is an aqueous solution of 10 and 35 nm diameter Silver Nano-particles. The experiment was performed to measure the temperature distribution and compare the heat pipe temperature difference using Nanofluid and DI-water. The tested Nano-particle concentrations ranged from 1, 10 and 100 mg/l. The condenser section of the heat pipe was attached to a heat sink that was cooled by water supplied from a constant temperature bath maintained at 40 °C. At a same charge volume, the measured Nanofluids filled heat pipe temperature distribution demonstrated that the temperature difference decreased 0.56–0.65 °C compared to DI-water at an input power of 30–50 W. In addition, the Nanofluid as working medium in heat pipe can up to 70 W and is higher than pure water about 20 W.
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effect of Silver Nano fluid on pulsating heat pipe thermal performance
Applied Thermal Engineering, 2008Co-Authors: Shungwen Kang, Huilun ChenAbstract:Abstract This paper presents preliminary experimental results on using copper tube having internal and external diameter with 2.4 mm and 3 mm, respectively, to carry out the experimental pulsating heat pipe. The working fluids include the Silver Nano-fluid water solution and pure water. In order to study and measure the efficiency, we compare with 20 nm Silver Nano-fluid at different concentration (100 ppm and 450 ppm) and various filled ratio (20%, 40%, 60%, 80%, respectively), also applying with different heating power (5 W, 15 W, 25 W, 35 W, 45 W, 55 W, 65 W, 75 W, 85 W, respectively). According to the experimental result in the midterm value (i.e. 40%, 60%) of filled ratio shows better. In the majority 60% of efficiency is considered much better. The heat dissipation effect is analogous in sensible heat exchange, 60% has more liquid slugs that will turn and carry more sensible heat, so in 60% of filled ratio, heat dissipation result is better than 40%, and the best filled fluid is 100 ppm in Silver Nano-fluid. Finally, we observed through the measurement comparison in thermal performance with pure water. When the heating power is 85 W, the average temperature difference and the thermal resistance of evaporator and condenser are decreased by 7.79 °C and 0.092 °C/W, respectively.
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experimental investigation of Silver Nano fluid on heat pipe thermal performance
Applied Thermal Engineering, 2006Co-Authors: Shungwen Kang, Shenghong Tsai, Shihyu YangAbstract:Abstract Nano-fluid is employed as the working medium for a conventional 211 μm wide × 217 μm deep grooved circular heat pipe. The Nano-fluid used in this study is an aqueous solution of 35 nm diameter Silver Nano-particles. The experiment was performed to measure the temperature distribution and to compare the heat pipe thermal resistance using Nano-fluid and DI-water. The tested Nano-particle concentrations ranged from 1 mg/l to 100 mg/l. The condenser section of the heat pipe was attached to a heat sink that was cooled by water supplied from a constant-temperature bath maintained at 40 °C. At a same charge volume, the measured Nano-fluid filled heat pipe temperature distribution demonstrated that the thermal resistance decreased 10–80% compared to DI-water at an input power of 30–60 W. The measured results also show that the thermal resistances of the heat pipe decrease as the Silver Nano-particle size and concentration increase.
