Open Access. Powered by Scholars. Published by Universities.®

Nanoscience and Nanotechnology Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 37

Full-Text Articles in Nanoscience and Nanotechnology

A Review On Nanomaterials And Nanohybrids Based Bio-Nanocomposites For Food Packaging, Kalpani Y. Perera, Amit K. Jaiswal, Swarna Jaiswal Dec 2022

A Review On Nanomaterials And Nanohybrids Based Bio-Nanocomposites For Food Packaging, Kalpani Y. Perera, Amit K. Jaiswal, Swarna Jaiswal

Articles

With an increasing demand for a novel, eco-friendly, high-performance packaging material “bio-nanocomposites” has attracted great attention in recent years. The review article aims at to evaluating recent innovation in bio-nanocomposites for food packaging applications. The current trends and research over the last three years of the various bio-nanocomposites including inorganic, organic nanomaterials, and nanohybrids, which are suitable as food packaging materials due to their advanced properties such as high mechanical, thermal, barrier, antimicrobial, and antioxidant are described in detail. In addition, the legislation, migration studies, and SWOT analysis on bio-nanocomposite film have been discussed. It has been observed that the …


Encapsulation Of Essential Oils In Nanocarriers For Active Food Packaging, Shubham Sharma, Lilly Mulrey, Megan Byrne, Amit Jaiswal, Swarma Jaiswal Jan 2022

Encapsulation Of Essential Oils In Nanocarriers For Active Food Packaging, Shubham Sharma, Lilly Mulrey, Megan Byrne, Amit Jaiswal, Swarma Jaiswal

Articles

Active packaging improves a packaging system’s effectiveness by actively integrating additional components into the packaging material or the headspace around the packaging. Consumer demand and awareness have grown enough to replace chemical agents with natural active agents. Essential oils (EOs) are extensively distributed throughout nature but at low levels and sometimes with poor recovery yields, which poses an issue with their application in food. Due to the instability of EOs when added directly into a food product, they require encapsulation before being added to a packaging matrix such as liposomes, solid-lipid nanoparticles, nano-emulsions, cyclodextrins, and nanostructured lipid nano-carriers. This article …


Enhanced Anticancer Response Of Curcumin- And Piperine-Loaded Lignin-G-P (Nipam-Co-Dmaema) Gold Nanogels Against U-251 Mg Glioblastoma Multiforme, Bilal Javed, Xinyi Zhao, Daxiang Cui, James Curtin, Furong Tian Oct 2021

Enhanced Anticancer Response Of Curcumin- And Piperine-Loaded Lignin-G-P (Nipam-Co-Dmaema) Gold Nanogels Against U-251 Mg Glioblastoma Multiforme, Bilal Javed, Xinyi Zhao, Daxiang Cui, James Curtin, Furong Tian

Articles

Glioblastoma multiforme (GBM) is the most aggressive and commonly diagnosed brain cancer and is highly resistant to routine chemotherapeutic drugs. The present study involves the synthesis of Lignin-g-p (NIPAM-co-DMAEMA) gold nanogel, loaded with curcumin and piperine, to treat GBM. The ongoing study has the application potential to (1) overcome the limitations of drugs biodistribution, (2) enhance the toxicity of anticancer drugs against GBM, and (3) identify the drugs uptake pathway. Atom transfer radical polymerization was used to synthesize the Lignin-g-PNIPAM network, crosslinked with the gold nanoparticles (GNPs) to self-assemble into nanogels. The size distribution and morphological analysis confirmed that the …


From Bench To Worktop: Rapid Evaluation Of Nutritional Parameters In Liquid Foodstuffs By Ir Spectroscopy, David Perezguaita Jan 2021

From Bench To Worktop: Rapid Evaluation Of Nutritional Parameters In Liquid Foodstuffs By Ir Spectroscopy, David Perezguaita

Articles

We evaluated the use of attenuated total reflectance infrared spectroscopy for simultaneous in situ quantification of the nutritional composition of liquid food stuffs in the industrial kitchen context. Different methodologies were compared, including dry and wet acquisition along with instrument parameters and measurement times of 4 and 60 s. The most effective technique was 1-minute measurement, with prediction errors of 2.6, 0.7, 1.0, 2.2, 0.8, 2.4 g/100 mL and 150 Kcal, for carbohydrates, proteins, fat, sugars, saturated fat, water and energy values, respectively.The 4-second method resulted in larger errors but was more applicable for inline measurements. Dry measurements successfully predicted …


In Depth Characterisation Of The Biomolecular Coronas Of Polymer Coated Inorganic Nanoparticles With Differential Centrifugal Sedimentation, André Perez-Potti, Hender Lopez, Beatriz Pelaz, Abuelmagd Abdelmonem, Mahmoud G. Soliman, Ingmar Schoen, Philip M. Kelly, Kenneth A. Dawson, Wolfgang J. Parak, Zeljka Krpetic, Marco P. Monopoli Jan 2021

In Depth Characterisation Of The Biomolecular Coronas Of Polymer Coated Inorganic Nanoparticles With Differential Centrifugal Sedimentation, André Perez-Potti, Hender Lopez, Beatriz Pelaz, Abuelmagd Abdelmonem, Mahmoud G. Soliman, Ingmar Schoen, Philip M. Kelly, Kenneth A. Dawson, Wolfgang J. Parak, Zeljka Krpetic, Marco P. Monopoli

Articles

Advances in nanofabrication methods have enabled the tailoring of new strategies towards the controlled production of nanoparticles with attractive applications in healthcare. In many cases, their characterisation remains a big challenge, particularly for small-sized functional nanoparticles of 5 nm diameter or smaller, where current particle sizing techniques struggle to provide the required sensitivity and accuracy. There is a clear need for the development of new reliable characterisation approaches for the physico-chemical characterisation of nanoparticles with significant accuracy, particularly for the analysis of the particles in the presence of complex biological fluids. Herein, we show that the Differential Centrifugal Sedimentation can …


Classification And Biological Identity Of Complex Nano Shapes, Luca Boselli, Hender Lopez, Wei Zhang, Qi Cai, Valeria A. Giannone, Jingji Li, Alirio Moura, João M. De Araujo, Jennifer Cookman, Valentina Castagnola, Yan Yan, Kenneth A. Dawson Jan 2020

Classification And Biological Identity Of Complex Nano Shapes, Luca Boselli, Hender Lopez, Wei Zhang, Qi Cai, Valeria A. Giannone, Jingji Li, Alirio Moura, João M. De Araujo, Jennifer Cookman, Valentina Castagnola, Yan Yan, Kenneth A. Dawson

Articles

Everywhere in our surroundings we increasingly come in contact with nanostructures that have distinctive complex shape features on a scale comparable to the particle itself. Such shape ensembles can be made by modern nano-synthetic methods and many industrial processes. With the ever growing universe of nanoscale shapes, names such as “nanoflowers” and “nanostars” no longer precisely describe or characterise the distinct nature of the particles. Here we capture and digitise particle shape information on the relevant size scale and create a condensed representation in which the essential shape features can be captured, recognized and correlated. We find the natural emergence …


Nitrogen-Vacancy Centers In Diamond For Nanoscale Magnetic Resonance Imaging Applications, Alberto Boretti, Lorenzo Rosa, Jonathan Blackledge, Stefania Castelletto Jan 2019

Nitrogen-Vacancy Centers In Diamond For Nanoscale Magnetic Resonance Imaging Applications, Alberto Boretti, Lorenzo Rosa, Jonathan Blackledge, Stefania Castelletto

Articles

The nitrogen-vacancy (NV) center is a point defect in diamond with unique properties for use in ultra-sensitive, high-resolution magnetometry. One of the most interesting and challenging applications is nanoscale magnetic resonance imaging (nano-MRI). While many review papers have covered other NV centers in diamond applications, there is no survey targeting the specific development of nano-MRI devices based on NV centers in diamond. Several different nano-MRI methods based on NV centers have been proposed with the goal of improving the spatial and temporal resolution, but without any coordinated effort. After summarizing the main NV magnetic imaging methods, this review presents a …


Surface Modification Of Silver Nanoparticle (Agnp) By Liposomal Encapsulation Mitigates Agnp-Induced Inflammation, Azeez O. Yusef, Alan Casey Jan 2019

Surface Modification Of Silver Nanoparticle (Agnp) By Liposomal Encapsulation Mitigates Agnp-Induced Inflammation, Azeez O. Yusef, Alan Casey

Articles

Silver nanoparticles (AgNP) are widely used in a variety of consumable products as antibacterial to prevent or treat infection. Unfortunately, evidence exits that AgNP induces inflammation which can worsen with repeated human exposure. However, there is little or no research on how to mitigate these adverse effects due to AgNP induced-toxicity. Here, we investigated if surface modification of AgNP by liposomal encapsulation suppresses AgNP-mediated inflammatory responses in THP1 monocytes and THP1 differentiated macrophages (TDM). AgNP was encapsulated in a dipalmitoyl phosphatidyl choline- (DPPC)/cholesterol-based liposome by extrusion through a 100-nm polycarbonate membrane to form Lipo-AgNP. It was found as expected that …


Evaluation Of Silver Nanoparticle Encapsulation In Dppc-Based Liposome By Different Methods For Enhanced Cytotoxicity, Azeez O. Yusef, Alan Casey Jan 2019

Evaluation Of Silver Nanoparticle Encapsulation In Dppc-Based Liposome By Different Methods For Enhanced Cytotoxicity, Azeez O. Yusef, Alan Casey

Articles

Here we carried out a comparative study on two cost and time effective methods of encapsulating silver nanoparticles (AgNP) in dipalmitoyl-phosphatidyl choline (DPPC)/cholesterol-based liposome to enhance nanoparticle cytotoxicity, and evaluated the effect of this on a blood cell line (THP1 monocytes) often involved in uptake of nanoparticles during human exposure. DLS and Zeta potential analyses over a 6-months period showed the extruded Lipo-AgNP (Ex-Lipo-AgNP) exhibited more stable characteristics when compared with the probe-sonicated Lipo-AgNP (PB-Lipo-AgNP). SEM microscopy indicated agglomeration of the PB-Lipo-AgNP which was not observed in Ex-Lipo-AgNP. Ex-Lipo-AgNP also exhibited higher temperature-dependent stability with 35.3% reduction in size from …


Advances In Diamond Nanofabrication For Ultrasensitive Devices, Stefania Castelletto, Lorenzo Rosa, Jonathan Blackledge, Mohammed Zaher Al Abri, Albert Boretti Oct 2017

Advances In Diamond Nanofabrication For Ultrasensitive Devices, Stefania Castelletto, Lorenzo Rosa, Jonathan Blackledge, Mohammed Zaher Al Abri, Albert Boretti

Articles

This paper reviews some of the major recent advances in single-crystal diamond nanofabrication and its impact in nano- and micromechanical, nanophotonics and optomechanical components. These constituents of integrated devices incorporating specific dopants in the material provide the capacity to enhance the sensitivity in detecting mass and forces as well as magnetic field down to quantum mechanical limits and will lead pioneering innovations in ultrasensitive sensing and precision measurements in the realm of the medical sciences, quantum sciences and related technologies.


Level Anticrossing Of Impurity States In Semiconductor Nanocrystals, Anvar S. Baimuratov, Ivan D. Rukhlenko, Vadim K. Turkov, Irina Ponomareva, Mikhail Yu Leonov, Tatiana S. Perova, Kevin Berwick, Alexander V. Baranov, Anatoly V. Federov Jan 2017

Level Anticrossing Of Impurity States In Semiconductor Nanocrystals, Anvar S. Baimuratov, Ivan D. Rukhlenko, Vadim K. Turkov, Irina Ponomareva, Mikhail Yu Leonov, Tatiana S. Perova, Kevin Berwick, Alexander V. Baranov, Anatoly V. Federov

Articles

The size dependence of the quantized energies of elementary excitations is an essential feature of quantum nanostructures, underlying most of their applications in science and technology. Here we report on a fundamental property of impurity states in semiconductor nanocrystals that appears to have been overlooked—the anticrossing of energy levels exhibiting different size dependencies. We show that this property is inherent to the energy spectra of charge carriers whose spatial motion is simultaneously affected by the Coulomb potential of the impurity ion and the confining potential of the nanocrystal. The coupling of impurity states, which leads to the anticrossing, can be …


New Approach Of Modifying The Anatase To Rutile Transition Temperature In Tio2 Photocatalysts, Ciara Byrne, Rachel Fagan, Steven Hinder, Declan Mccormack, Suresh Pillai Jan 2016

New Approach Of Modifying The Anatase To Rutile Transition Temperature In Tio2 Photocatalysts, Ciara Byrne, Rachel Fagan, Steven Hinder, Declan Mccormack, Suresh Pillai

Articles

In pure synthetic titanium dioxide, the anatase to rutile phase transition usually occurs between the temperatures of 600 °C and 700 °C. The phase transition temperature can be altered by various methods, including modifying the precursor or by adding dopant or modifier to the TiO2 sample. In an attempt to investigate the phase transition using aromatic carboxylic acids, the current study examines the impact of increasing concentrations of benzoic acid (1 : 0, 1 : 1, 1 : 4 and 1 : 8 molar ratio TiO2 : benzoic acid) on anatase to rutile transition. The samples were characterised using Raman …


Synthesis And Doping Feasibility Of Composite-Hydroxide-Mediated Approach For The Cu1-Xznxo Nanomaterials, Tauseef Shahid, Muhammad Arfan, Waqas Ahmad, Tayyaba Bibi, Taj Muhammad Khan Jan 2016

Synthesis And Doping Feasibility Of Composite-Hydroxide-Mediated Approach For The Cu1-Xznxo Nanomaterials, Tauseef Shahid, Muhammad Arfan, Waqas Ahmad, Tayyaba Bibi, Taj Muhammad Khan

Articles

In this article, we report feasibility of composite hydroxide-mediated (CHM) approach for the synthesis and doping of Cu1-xZnxO (x=0%, 3%, 6% and 9%) nanomaterial. The proposed method offers a low cost, low temperature and environmentally friendly approach to preparing doped nanomaterials in a feasible and cost- effective route. Further, we investigate the effect of incorporated Zn +2 on the properties of produced Cu (II) O nanostructures. The X-ray diffraction analysis confirms formation of the single-phase monoclinic Cu (II) O and incorporation of Zn at the Cu-lattice sites. The crystalline structure is improved and the average grain size has increased from …


Anti-Bacterial Activity Of Indoor Light Activated Photocatalysts, Suresh Pillai, Michael Seery, Damian Synnott, Stephen Hinder, Georg Michlits Feb 2013

Anti-Bacterial Activity Of Indoor Light Activated Photocatalysts, Suresh Pillai, Michael Seery, Damian Synnott, Stephen Hinder, Georg Michlits

Articles

Nanocrystalline photocatalysts, prepared under ambient conditions using a microwave assisted syn-thesis, show indoor light photocatalytic activity for the degradation of Staphylococcus aureus and Escherichia coli. The zinc sulphide (ZnS) nanomaterials, prepared by a microwave assisted synthesis, are shown to be cubic blende structure with an average crystallite size of 4–6 nm. The anti-bacterial activ-ity of these nanomaterials is investigated under irradiation from a 60 W light bulb and photocatalytic activity is revealed to be due to the defects present in the crystal structure. The ZnS shows anti-bacterial action as both a bacteriostatic and bacteriocidal (88% reduction in the amount of …


Ecotoxicological Assessment Of Silica And Polystyrene Nanoparticles Assessed By A Multitrophic Test Battery, Maria Casado-Gavalda, Ailbhe Macken, Hugh Byrne Jan 2013

Ecotoxicological Assessment Of Silica And Polystyrene Nanoparticles Assessed By A Multitrophic Test Battery, Maria Casado-Gavalda, Ailbhe Macken, Hugh Byrne

Articles

The acute ecotoxicity of different diameters of silica and polyethyleneimine polystyrene (PS-PEI)nanoparticles (NPs)was assessed on a test battery of aquatic organisms representing different trophic levels. Daphnia magna, Thamnocephalus platyurus, Pseudokirchneriella subcapitata and Vibrio fischeri, were employed in a series of standard acute ecotoxicity tests and work was complemented with two cytotoxicological end points on a rainbow trout gonadal cell line (RTG-2). Physico-chemical characterization of the NPs was performed in the different test media employed, using dynamic light scattering (DLS) and zeta potentiometry. In contrast to silica NPs exposure, for which no effect was observed for concentrations up …


Technical Note: Friction Factor Diagrams For Pipe Flow, Jim Mcgovern Oct 2011

Technical Note: Friction Factor Diagrams For Pipe Flow, Jim Mcgovern

Articles

This technical note describes diagrams of friction factor for pipe flow that have been prepared using, mainly, the equations that Lewis Moody used to prepare his famous diagram in 1944. The preparation of the new diagrams was prompted by the need for vector graphics versions that could be used for teaching purposes and that could be distributed freely to students and others under a Creative Commons Attribution-Share-Alike license. Using a structure very similar to that of Moody's diagram, variants with the Darcy friction factor and the Fanning friction factor have been prepared. In addition, variants have been prepared that include …


Intracellular Localisation, Geno- And Cytotoxic Response Of Poly N-Isopropylacrylamide (Pnipam) Nanoparticles To Human Keratinocyte (Hacat) And Colon Cells (Sw 480), Pratap Naha, Kunal Bhattacharya, Tiziana Tenuta, Kenneth Dawson, Iseult Lynch, Amaya Gracia, Fiona Lyng, Hugh Byrne Oct 2010

Intracellular Localisation, Geno- And Cytotoxic Response Of Poly N-Isopropylacrylamide (Pnipam) Nanoparticles To Human Keratinocyte (Hacat) And Colon Cells (Sw 480), Pratap Naha, Kunal Bhattacharya, Tiziana Tenuta, Kenneth Dawson, Iseult Lynch, Amaya Gracia, Fiona Lyng, Hugh Byrne

Articles

PNIPAM nanoparticles, with and without a covalentlylinked fluorescent label, were prepared by a free radical polymerisation technique. The cyto and genotoxicity of PNIPAM nanoparticles were analysed in two representative mammalian cell lines, SW480, a colon, and HaCaT, a dermal cell line. Physical characterisation in terms of particle size and zeta potential of the PNIPAM nanoparticles was carried out both in aqueous solution and in the appropriate cell culture media. Uptake and colocalisation of fluorescently labelled PNIPAM nanoparticles was monitored in both cell lines using confocal laser scanning microscopy. Genotoxicity analysis using the Comet assay was performed in both cell lines …


Optical Limiting Study Of Double Wall Carbon Nanotube-Fullerene Hybrids, Kang-Shyang Liao, Jun Wang, Daniel Fruchtl, Nigel Alley, Enrico Andreoli, Eoghan Dillon, Andrew Barron, Hansoo Kim, Hugh Byrne, Werner Blau, Seamus Curran Apr 2010

Optical Limiting Study Of Double Wall Carbon Nanotube-Fullerene Hybrids, Kang-Shyang Liao, Jun Wang, Daniel Fruchtl, Nigel Alley, Enrico Andreoli, Eoghan Dillon, Andrew Barron, Hansoo Kim, Hugh Byrne, Werner Blau, Seamus Curran

Articles

In order to merge complementary temporal and spatial nonlinear optical characteristics of Fullerene and carbon nanotubes, synthesis of double wall carbon nanotube-Fullerene hybrid was performed by covalently linking DWNT and C60 by amination reaction with polyethylenimine. DWNT-Fullerene hybrids were characterized by thermogravimetric analysis, UV-vis spectroscopy and transmission electron microscopy. Optical limiting performance of DWNT-Fullerene hybrids is superior to those of Fullerenes and SWNTs at the same level (~ 80%) of transmission. Whereas nonlinear scattering is an evident mechanism, reverse saturable absorption from Fullerene moieties has significant contribution. Charge transfer between the DWNT and Fullerene moieties may play an important role …


Fourier Transform Infrared Microspectroscopy And Multivariate Methods For Radiobiological Dosimetry, Aidan Meade, Colin Clarke, Hugh Byrne, Fiona Lyng Feb 2010

Fourier Transform Infrared Microspectroscopy And Multivariate Methods For Radiobiological Dosimetry, Aidan Meade, Colin Clarke, Hugh Byrne, Fiona Lyng

Articles

The scientific literature contains an ever-growing number of reports of applications of vibrational spectroscopy as a multivariate non-invasive tool for analysis of biological effects at the molecular level. Recently, Fourier transform infrared microspectroscopy (FTIRM) has been demonstrated to be sensitive to molecular events occurring in cells and tissue after exposure to ionizing radiation. In this work the application of FTIRM in the examination of dose-dependent molecular effects occurring in skin cells after exposure to ionizing radiation with the use of partial least-squares regression (PLSR) and generalized regression neural networks (GRNN) was studied. The methodology is shown to be sensitive to …


Three Dimensional Collagen Gels As A Cell Culture Matrix For The Study Of Live Cells By Raman Spectroscopy, Franck Bonnier, Aidan Meade, S. Merzha, Peter Knief, Kunal Bhattacharya, Fiona Lyng, Hugh Byrne Jan 2010

Three Dimensional Collagen Gels As A Cell Culture Matrix For The Study Of Live Cells By Raman Spectroscopy, Franck Bonnier, Aidan Meade, S. Merzha, Peter Knief, Kunal Bhattacharya, Fiona Lyng, Hugh Byrne

Articles

Three dimensional collagen gels are evaluated as matrices for the study of live cells by Raman spectroscopy. The study is conducted on a human lung adenocarcinoma (A549) and a spontaneously immortalized human epithelial keratinocyte (HaCaT) cell line. It is demonstrated, using the Alamar Blue assay, that both cell models exhibit enhanced viability in collagen matrices compared to quartz substrates, commonly used for Raman spectroscopy. Using principal component analysis, it is shown that the Raman spectral analysis of cells in collagen matrices are minimally contaminated by substrate contributions and the cell to cell spectral variations are greatly reduced compared to those …


An Investigation Of The Rwpe Prostate Derived Family Of Cell Lines Using Ftir Spectroscopy, M. Baker, Colin Clarke, D. Demoulin, J. Nicolson, Fiona Lyng, Hugh Byrne, C. Hart, M. Brown, N. Clarke, P. Gardner Jan 2010

An Investigation Of The Rwpe Prostate Derived Family Of Cell Lines Using Ftir Spectroscopy, M. Baker, Colin Clarke, D. Demoulin, J. Nicolson, Fiona Lyng, Hugh Byrne, C. Hart, M. Brown, N. Clarke, P. Gardner

Articles

Interest in developing robust, quicker and easier diagnostic tests for cancer has lead to an increased use of Fourier transform infrared (FTIR) spectroscopy to meet that need. In this study we present the use of different experimental modes of infrared spectroscopy to investigate the RWPE human prostate epithelial cell line family which are derived from the same source but differ in their mode of transformation and their mode of invasive phenotype. Importantly, analysis of the infrared spectra obtained using different experimental modes of infrared spectroscopy produce similar results. The RWPE family of cell lines can be separated into groups based …


A Comparative Study Of The Interaction Of Different Polycyclic Aromatic Hydrocarbons On Different Types Of Single Walled Carbon Nanotubes, Sourabhi Debnath, Qiaohun Cheng, Theresa Hedderman, Hugh Byrne Jan 2010

A Comparative Study Of The Interaction Of Different Polycyclic Aromatic Hydrocarbons On Different Types Of Single Walled Carbon Nanotubes, Sourabhi Debnath, Qiaohun Cheng, Theresa Hedderman, Hugh Byrne

Articles

A comparative study of the solubilising effect of polycyclic aromatic hydrocarbon (PAHs) on single walled carbon nanotubes (SWCNTs) produced by high pressure decomposition of carbon monoxide (HiPco) and the arc discharge (AD) method has been carried out with the aid of fluorescence and Raman spectroscopy. For this study, polyphenyl and polyacene PAHs of different lengths are used. From the study it has been found that the binding energy of PAHs with AD SWCNTs is the same as that with HiPco SWCNTs. Shorter PAHs molecules better solubilise SWCNTs and in general smaller diameter SWCNTs. Thus, given their smaller diameter profile, significantly …


Ultrasound-Assisted Swnts Dispersion: Effects Of Sonication Parameters And Solvent Properties, Qiaohuan Cheng, Sourabhi Debnath, Elizabeth Gregan, Hugh Byrne Jan 2010

Ultrasound-Assisted Swnts Dispersion: Effects Of Sonication Parameters And Solvent Properties, Qiaohuan Cheng, Sourabhi Debnath, Elizabeth Gregan, Hugh Byrne

Articles

Ultrasonication is widely used for preparing Single-Walled Carbon Nanotube (SWNT) dispersions in different solvent media and it has been shown to play a critical role in dispersing and debundling SWNTs. The strong shear force that can exfoliate the SWNT bundles during sonication comes from cavitation, which entails a process of bubble formation, growth, and collapse. The efficiency of the cavitation process is closely correlated to many solvent parameters, including vapor pressure, viscosity, and surface tension, as well as the sonication frequency, intensity, and time. In this study, SWNTs were dispersed in a range of organic solvents assisted by tip sonication. …


Resonant Mie Scattering (Rmies) Correction Of Infrared Spectra From Highly Scattering Biological Samples Analyst, Paul Bassan, Achim Kohler, Harald Martens, Joe Lee, Hugh Byrne, Paul Dumas, Ehsan Gazi, Michael Brown, Noel Clarke, Peter Gardner Jan 2010

Resonant Mie Scattering (Rmies) Correction Of Infrared Spectra From Highly Scattering Biological Samples Analyst, Paul Bassan, Achim Kohler, Harald Martens, Joe Lee, Hugh Byrne, Paul Dumas, Ehsan Gazi, Michael Brown, Noel Clarke, Peter Gardner

Articles

Infrared spectra of single biological cells often exhibit the “dispersion artefact” observed as a sharp decrease in intensity on the high wavenumber side of absorption bands, in particular the Amide I band at ~1655 cm-1, causing a downward shift of the true peak position. The presence of this effect makes any biochemical interpretation of the spectra unreliable. Recent theory has shed light on the origins of the ‘dispersion artefact’ which has been attributed to resonant Mie scattering (RMieS). In this paper a preliminary algorithm for correcting RMieS is presented and evaluated using simulated data. Results show that the ‘dispersion artefact’ …


Reflection Contributions To The Dispersion Artefact In Ftir Spectra Of Single Biological Cells, Paul Bassan, Hugh Byrne, Joe Lee, Franck Bonnier, Colin Clarke, Paul Dumas, Ehsan Gazi, Michael Brown, Noel Clarke, Peter Gardner Apr 2009

Reflection Contributions To The Dispersion Artefact In Ftir Spectra Of Single Biological Cells, Paul Bassan, Hugh Byrne, Joe Lee, Franck Bonnier, Colin Clarke, Paul Dumas, Ehsan Gazi, Michael Brown, Noel Clarke, Peter Gardner

Articles

Fourier transform infrared spectra of a single cell in transflection geometry are seen to vary significantly with position on the cell, showing a distorted derivative-like lineshape in the region of the optically dense nucleus. A similar behaviour is observable in a model system of the protein albumin doped in a potassium bromide disk. It is demonstrated that the spectrum at any point is a weighted sum of the sample reflection and transmission and that the dominance of the reflection spectrum in optically dense regions can account for some of the spectral distortions previously attributed to dispersion artefacts. Rather than being …


One-Pot Synthesis Of Anionic (Nitrogen) And Cationic (Sulfur) Codoped High-Temperature Stable, Visible Light Active, Anatase Photocatalysts, Suresh Pillai, Declan Mccormack, Steven Hinder, Pradeepan Periyat Jan 2009

One-Pot Synthesis Of Anionic (Nitrogen) And Cationic (Sulfur) Codoped High-Temperature Stable, Visible Light Active, Anatase Photocatalysts, Suresh Pillai, Declan Mccormack, Steven Hinder, Pradeepan Periyat

Articles

No abstract provided.


Synthesis Of Maleic Anhydride Grafted Polypropylene-Butadiene Copolymer And Its Application In Pp/Ommt/Sbs Composite As Compatibilizer, Qiaohuan Cheng, Zhanxia Lu, Hugh Byrne Jan 2009

Synthesis Of Maleic Anhydride Grafted Polypropylene-Butadiene Copolymer And Its Application In Pp/Ommt/Sbs Composite As Compatibilizer, Qiaohuan Cheng, Zhanxia Lu, Hugh Byrne

Articles

Maleic Anhydride (MA) grafted propylene-butadiene copolymer (PPB) was prepared. FTIR and 1H-NMR results indicated that the MA molecules reacted with the double bond in the butadiene unit of the PPB and the grafting percentage increased with the butadiene content in the initial copolymer. GPC results showed the introduction of butadiene in the copolymer prevented the degradation of the PPB. The MA-g-PPB (MPPB) was applied in PP/SBS/OMMT composite as compatibilizer. In the presence of 10phr MPPB, the impact strength of the composite was improved by ~20%. XRD patterns indicated the formation of β-phase crystallization of polypropylene in the presence of MPPB …


One-Pot Synthesis Of Anionic (Nitrogen) And Cationic (Sulfur) Codoped High-Temperature Stable, Visible Light Active, Anatase Photocatalysts, Suresh Pillai, Declan Mccormack, Steven Hinder, Pradeepan Periyat Jan 2009

One-Pot Synthesis Of Anionic (Nitrogen) And Cationic (Sulfur) Codoped High-Temperature Stable, Visible Light Active, Anatase Photocatalysts, Suresh Pillai, Declan Mccormack, Steven Hinder, Pradeepan Periyat

Articles

No abstract provided.


The Bundle Dispersion Of Swnt On Interaction With P-Terphenyl, Theresa Hedderman, Anika Mostaert, Anne Shanahan, Hugh Byrne Jan 2009

The Bundle Dispersion Of Swnt On Interaction With P-Terphenyl, Theresa Hedderman, Anika Mostaert, Anne Shanahan, Hugh Byrne

Articles

This paper investigates the interaction and bundle dispersion of single walled carbon nanotubes (SWNT) produced by arc discharge and by the high pressure decomposition of carbon monoxide, often referred to as the HiPco method, in the presence of the molecule p-terphenyl. The study will show that the extent of SWNT bundle dispersion and the degree of interaction with p-terphenyl is related to the level of purity of the SWNT sample. This study compares the bundle dispersion and interaction of SWNT with p-terphenyl in their as produced state and after purification. A number of spectroscopic and microscopic techniques are used to …


Titanium Dioxide Nanoparticles Induce Oxidative Stress And Dna-Adduct Formation But Not Dna-Breakage In Human Lung Cells, Kunal Bhattacharya, Maria Davoren, Jens Boertz, Roel P.F. Schins, Eik Hoffmann, Elke Dopp Jan 2009

Titanium Dioxide Nanoparticles Induce Oxidative Stress And Dna-Adduct Formation But Not Dna-Breakage In Human Lung Cells, Kunal Bhattacharya, Maria Davoren, Jens Boertz, Roel P.F. Schins, Eik Hoffmann, Elke Dopp

Articles

Titanium dioxide (TiO2), also known as titanium (IV) oxide or anatase, is the naturally occurring oxide of titanium. It is also one of the most commercially used form. To date, no parameter has been set for the average ambient air concentration of TiO2 nanoparticles (NP) by any regulatory agency. Previously conducted studies had established these nanoparticles to be mainly non-cyto- and -genotoxic, although they had been found to generate free radicals both acellularly (specially through photocatalytic activity) and intracellularly. The present study determines the role of TiO2-NP (anatase, ∅ < 100 nm) using several parameters such as cyto- and genotoxicity, DNA-adduct formation and generation of free radicals following its uptake by human lung cells in vitro. For comparison, iron containing nanoparticles (hematite, Fe2O3, ∅ < 100 nm) were used. The results of this study showed that both types of NP were located in the cytosol near the nucleus. No particles were found inside the nucleus, in mitochondria or ribosomes. Human lung fibroblasts (IMR-90) were more sensitive regarding cyto- and genotoxic effects caused by the NP than human bronchial epithelial cells (BEAS-2B). In contrast to hematite NP, TiO2-NP did not induce DNA-breakage measured by the Comet-assay in both cell types. Generation of reactive oxygen species (ROS) was measured acellularly (without any photocatalytic activity) as well as intracellularly for both types of particles, however, the iron-containing NP needed special reducing conditions before pronounced radical generation. A high level of DNA adduct formation (8-OHdG) was observed in IMR-90 cells exposed to TiO2-NP, but not in cells exposed to hematite NP. Our study demonstrates different modes of action for TiO2- and Fe2O3-NP. Whereas TiO2-NP were able to generate elevated amounts of free radicals, which induced indirect genotoxicity mainly by DNA-adduct formation, Fe2O3-NP were clastogenic (induction of DNA-breakage) and required reducing conditions for radical formation.