The First International Palestinian Conference on Nanotechnology for Advanced Material and Devices
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- ItemModification Of Cds/FTO Thin Films Solar Cells Fabricated By Combined Electro- Deposition And Chemical Bath Deposition(2012-03-26) Mu›min Mari’e; Ahed Zyoud; Sahar Khudruj; Hikmat S. Hilal
In recent years, polycrystalline CdS thin films have received intensive attention due their major role in the photovoltaic technology and optoelectronic devices. They have been used as partner of several types of thin film solar cells, such as, Cu2S, CuInSe2, and CdTe. Specifically, CdTe/CdS heterojunction solar cells with efficiency of about 16% have been reported. CdS thin films can be prepared by several methods, such as, electrodeposition, vacuum evaporation, screen printing, photochemical deposition, CBD, spray pyrolysis, and sputtering. Among all these, chemical bath deposition and electrodeposition techniques are con- venient low-cost processes and useful for large area industrial application. FTO/CdS nano-films prepared by electrochemical (EC) and chemical bath (CBD), separately and combined together have been described by Sahar Khudruj in this lab. The target was to produce a new type of CdS solar cells with high efficiency and high stability. In this work, a new strategy has been developed to modify the resulting films using annealing, cooling rate control and then coverage with electro-active materials imbedded inside polymer matrices. CdS film annealing enhanced the solar cell effi ciency, while the polymer matrix coating enhanced its stability Characterization of the prepared thin films was achieved by UV-visible spectrophotometry, photoluminescence, AFM, SEM and XRD.
- ItemMagnetotransport in Graphene(2012-03-26) H. Shanak; A. Hueten; R. Schloesser; T. Heinzel
Graphene is a flat single layer of carbon atoms tightly packed into a two-dimensional (2D) honeycomb lattice, and is a basic building block for graphite material. It can be wrapped up into 0D fullerenes, rolled into 1D nanotubes or stacked into 3D graphite. The band structure of monolayer graphene is unusual, where it is a zero-gap semi- conductor with a linear energy dispersion relation and the charges behave as massless Dirac fermions. Charge transport in graphene exhibits a number of novel phenomena, such as the half-integer quantum Hall effect. Technologically, graphene attracts a special attention as a promising post-silicon electronic material due to its exceptional mobility, current-carrying capacity, and thermal conductivity. In this work the graphene samples were produced by the use of the mechanical ex- foliation method. Si wafer was used as a substrate with a precise 300nm oxide layer on top. The initial identification of the graphene was performed using the optical microscope by means of the interference contrast. The thickness (number of layers) was determined by the use of the Atomic force microscopy and the Raman spectroscopy. Electron beam lithography was used to make metallization contact the graphene with special electrodes. Standard hall measurements were performed with a perpendicular magnetic field. The resistance (Rxx and Ryx) was measured as a function of the magnetic field with temperature as a parameter. Shubnikov de Haas Oscillation dependence on temperature was studied. Different parameters such as effective mass and carrier density were determined. Weak localization was studied for some samples.
- ItemBiocompatible Nanoemulsion: Phase Behavior, Formulation, Characterization and Some Application(2012-03-26) Asalah AL-Jundy
Isotretinoin is 13-cis-retinoic acid and is related to both retinoic acid and Retinol (Vitamin A). It has been commonly used for the treatment of severe acne and the other dermatological diseases , isotretinoin has some deficiencies, such as poor solubility in water and in most organic solvents and poor stability, being easily oxidized when heated or exposed to light.
Because water insoluble drugs often show low absorption and weak bioavailability, improvement in solubility is important for development of drug preparations .
Drugs can be solubilized and formulated in nanoemulsions . nanoemulsions are excellent candi- dates as potential drug delivery systems because of their improved drug solublization , long shelf life and ease of preparation .
Recently, Tetronic surfactants have been studied as possible vehicles for drug delivery; hence, studies on their behavior under a variety of conditions will be an important part of the formulation in delivery agents.
Tetronic 1107 is a tetrafunctional block copolymer surfactant terminating in primary hydroxyl groups see figure (1) . A nonionic surfactant that is 100% active and nontoxic This study aims to investigate the phase behavior of Tetronics 1107 with Propylene Glycol as a model oil and cationic surfactant tetra butyl ammonium bromide at different temperature (25,37,and 45 C), and then investigate the phase behavior of Tetronics 1107 with R (+)-Limonene oil at different temperature (25,37C ) to form nanoemulsion in order to improve solubility of isotretinoin.
Visual inspection , cross polarizers and polarized microscopy were used to detect anisotropy . A cubic phase and micelle were detected in the corresponding ternary phase diagram. each of them will be used to formulate of isotretinoin in a second stage. - ItemPartnerships in Global LED Lighting Technology(2012-03-26) Patricia Schneider
PolyBrite International is an innovative global lighting technology company that develops state of the art LED lighting systems. It strives to create partnerships world- wide in the lighting business. As executive vice president, I oversee the legal aspects of the partnerships. I will present brief remarks about some of our experience in this arena. Our proprietary technology brings the energy, environmental and economic advantages of LED technology to the marketplace. I will make brief remarks about our experience in creating global partnerships for lighting solutions.
- ItemEnhanced Anti-Dermatophytic Effect Of Nanoparticles Stimulated By Laser And Cold Plasma Techniques(2012-03-26) Salama A. Ouf; Abdel-Aleam H. Mohamed
Dermatophytosis is the infection of keratinized tissues such as hair, nail and the stratum corneum of the skin by dermatophytic fungi. Infection is generally cutaneous and restricted to the non-living cornified layers because of the inability of the fungi to penetrate the deeper tissues or organs of immunocompetent hosts. In Saudi Arabia, Ony-chomycosis is the most frequent infection (40.3%), followed by tinea capitis (21.9%), tinea pedis (16%), tinea cruris (15.1%), and tinea corporis (6.7%). Several azole compounds have been tried to control dermatophytic infection, however, the azole-containing medicines may interfere with the activity of hepatic microsomal enzymes, sex and thyroid hormones, and testosterone biosynthesis. In this research, antibody-conjugated nanoparticles stimulated by cold plasma and laser was evaluated in vitro against some dermatophytes isolated from the common types of tinea. Different types of nanomaterials like copper, zinc, titanium, magnesium, gold, alginate and silver were tested but silver nanoparticles was proved to be most effective against the dermatophytes under test. The use of cold plasma coupled with antibody-conjugated nanoparticles has severe impact on dermatophytes where the inhibition of growth, spore germination keratinase activity was more than 88% in the case of Trichophyton rubrum, T. violaceum, Microsprum canis and M. gypseum. Complete inhibition of growth for all dermatophytes was brought about by the interaction of conjugated nanoparticles, with cold plasma and laser treatment.
- ItemOptical, Morphological And Electrical Characterization Of Poly (3-Hexylthiophene) (P3HT) And Phenyl-C61-Butyric Acid Methyl Ester (PCBM) Used In Pho-Tovoltaic Devices(2012-03-26) Jamal Ghabboun; Marc Chaigneau; Mukhles Sowwan; Maryam faroun; Zafer Hawash
Organic photovoltaics currently lag behind their “inorganic” counterparts because of low solar energy conversion efficiencies. Several research groups are addressing conversion efficiency by employing a combination of nanomaterials and unique nanoscale architectures. Recently, new hybrid organic-inorganic photovoltaics are being studied and known as third generations’ solar cells. These photovoltaics consist of light absorbing polymers in contact with semiconductor nanocrystals or nanostructured metals. The nanomaterials affect electro-optical properties of the conducting polymer, which include assisting in absorption of red and near-IR photons, a significant portion of the solar spectrum. To investigate thoroughly these new generation of solar cells containing potential efficient polymers, devices composed of PCBM (acceptor type fullerene C60), P3HT (donor conjugated polymer) and another low band gap material (LBG, undisclosed compound) have been prepared. High resolution AFM images have been carried out for surface characterization. Flat surface without any distinct structure was observed in the AFM images of the sample reference (1:1:0 / P3HT:PCBM:LGB) in contrast with a phase separated structure appeared with different domain size from 10 nm to 200 nm depending on the organic molecules concentration. The organic solar cell with low band gap (0.76:1:0.23 P3HT/P1/PCBM) ratios showed improvement in efficiency. In this case, the average domain sizes are estimated to be 11 nm, approaching the ideal domain of the exciton diffusion length. A finer phase separation observed confirms the intimate mixing of P3HT and PCBM at the nanoscale. One can clearly observe well-defined interfaces where the phase separation within the P3HT and PCBM can be seen as bright and dark regions, which are attributed to polymer rich domains and PCBM-rich domains, respectively. A relationship has been performed between the pho- tovoltaic performance and morphology. Furthermore, Raman spectroscopy is used to clearly identify the chemical nature of the different domains. First measurements showed that the Raman signal of P3HT completely masked that of PCBM. Further work is in progress to optimize PV performance of these copolymers.
- ItemCdS Thin Film Photoelectrochemical Electrodes: Combined Electrochemical & Chemical Bath Depositions(2012-03-26) Sahar Khudruj; Hikmat S.Hilal; Ahed Zyoud; AndIyad Saad Eddin
Nano-sized CdS films were deposited onto FTO/glass substrates by different techniques, namely: electrochemical (EC), chemical bath (CB) and electrochemical followed by chemical bath (EC/CB) deposition techniques. The latter technique is examined here for the first time. Scanning electron microscopy (SEM), X-Ray diffraction (XRD), photoluminescence spectra (PL) and electronic absorption spectra were studied for different films. Photo-electrochemical (PEC) characteristics of different films, such as photo (J-V) plots, dark (J-V) plots, conversion efficiency and stability, were all investigated. Films prepared by different methods showed different SEM images. Electronic absorption spectra for different films were not much different except in PL intensity values. PEC characteristics for different films showed different behaviors. The EC/CBD films showed higher light-to-electricity conversion efficiency than EC films, but lower efficiency than CBD counterparts. Moreover, the EC/CBD films showed higher values of JSC with time, than either EC or CBD counterparts, which give an idea about the advantage of the new described films. The deposited films were modified by annealing at 250oC under N2. Cooling of pre- heated films to room temperature was performed by a gradual slow process. The effect of annealing & slow cooling on film characteristics, such as XRD, SEM, PL, electronic absorption spectra were all measured for different films. Photo-electrochemical characteristics of different films, such as: open-circuit voltage (Voc), current density (Jsc), photo (J-V) plots, efficiency and stability, were studied. Films treated by annealing & slow cooling showed higher conversion efficiency than their un-treated counterparts. SEM images showed that annealing increased the grain size of CdS nano particle in cases of CBD, EC and EC/CBD. XRD measurements showed that annealing lowered the crystallite size for EC-CdS films, whereas annealing enhanced the crystallite size for both CBD-CdS and EC/CBD-CdS films. Photoluminescence spectra were not af- fected by annealing except in PL intensity values. In each prepared CdS film, annealing enhanced PEC characteristics, by increasing conversion efficiency and stability. On the other hand, the annealed EC/CBD showed higher conversion efficiency and stability than either the annealed EC or CBD films. On the other hand, the higher conversion efficiency of both annealed CBD-CdS and EC/CBD-CdS films than non-annealed counterparts coincided with SEM topography, XRD spectra and PL intensity results. XRD patterns showed enhancement in crystal- lite size for both annealed CBD-CdS and EC/CBD-CdS films. SEM images showed homogenized layers with more ordered and uniformly packed coagulates for annealed films. In addition, PL spectra for annealed films exhibited higher emission values than non-annealed films. This is because annealing enhances the particle characteristics, giving more uniform and compact surface and consequently higher PL intensity. The results indicate that the new CdS nano-films, prepared by EC/CBD technique, are advantageous over other earlier known types.
- Itemأين المناهج المدرسية من علم وتقنية النانو(2012-03-26) أ.د. محمد السبوع
- ItemPolylactide Microcapsules and Films: Preparation and Properties(2012-03-26) Hassan Ismaiel Sawalha
Polylactide (PLA) is a biodegradable, biocompatible, and nontoxic polyester, which has various applications i.e. in the biomedical, and pharmaceutical field. In the bio- medical field, PLA is used to prepare different types of biomaterials e.g. sutures, bone screws, scaffolds, films for tissue engineering, and microcapsules for controlled drug delivery systems. Besides, hollow PLA microcapsules can be used as ultrasound contrast agent (UCA). Imaging of the body with ultrasound can be significantly improved when UCA’s are used because these capsules can resonate in the acoustic field which increases the backscatter signal of the ultrasound. Loading the UCA’s with drugs gives extra benefits as the drug can be released at the desired location by bursting the capsules with the ultrasound. Successful application of these capsules in the body requires control over their properties. The overall aim of the thesis is to produce hollow microcapsules with controlled properties including size, size distribution, structure, and thermal and mechanical properties. The microcapsules were prepared with multistage premix membrane emulsification of PLA/dichloromethane/template liquid (i.e. oil) solutions in a nonsolvent solution consists of water or water-alcohol mixtures and proper surfactant (polyvinyl alcohol). After emulsification, the solvent is extracted into the nonsolvent, and consequently the polymer solidifies into polymeric shell around the oil droplet which can be removed later by freeze drying to from hollow microcapsules. *The research described here was conducted at the laboratory of Food and Bioprocess engineering group, Wageningen University, Wageningen, the Nether- lands, under the supervision of Professor Remko Boom and Dr. Karin Schroën.
- ItemNanoscale Technology Research And Development: What Are The Challenges Ahead?(2012-03-26) Dr. Hasan M. Nayfeh
After receiving his Ph.D. degree in Electrical Engineering for his dissertation on nanoscale Strained-Silicon electron devices from MIT in 2003, Dr. Nayfeh joined IBM SRDC, where he is currently senior engineer with responsibility for technology re- search and development. Dr. Nayfeh’s nanoscale device design work has resulted in the successful deployment of 65 and 45-nm technology-nodes, enabling integrated chips (ICs) that are more powerful compared to prior technologies due to increased circuit functionality measured as the product of speed and density at fixed power density. Such ICs are found in commercial products including the IBM system p and z server machines, and Nintendo Wii, Sony PlayStation, and Microsoft X-Box game consoles. In this talk, I will discuss the challenges involved to continue with successful technology deployment of future nodes, as 9-nm technology will be reaching market towards the end of this decade, in order to satisfy consumer demand for faster performance and lower power electronic products, and how universities/research institutions, in this region can contribute technically to this challenge from the experimental, theoretical and student training perspectives. Considerable innovation, covering the fields of electrical engineering, materials science, chemistry, and physics, will be required to support such small nanoscale dimensions. Already, power dissipation for an IC is roughly equal to that of a light bulb (200 W/cm2), and as devices are scaled further, this density is expected to increase further, due to physical limits on scaling that are almost impossible to break due to quantum mechanical tunneling leakage and reliability requirements, such as the gate insulator thickness which is near the limit of 1-nm which is only a few monolayers of atoms. Furthermore, since the minimum contacted pitch that is project- ed for the 9-nm technology node is only 50-nm, aggressive scaling of the gate length down to around 10-nm is required simply in order to have sufficient space to integrate the electrical contacts. This is an extremely difficult integration challenge due to such tight space, and a difficult physics problem due to high leakage in such 10-nm devices. Furthermore, the transport physics at such small dimensions will require more advanced modeling that includes quantum mechanical scattering effects in order to predict the drive current in such devices accurately. There are several paths under investigation for reducing power density, but I will focus on two that are promising, and they are: (1) moving from a planar to a non-planar design structure, and (2) heterogenous integration of novel channel materials with Silicon. The non-planar design results in less leakage due to improved gate control over the charged carriers, allowing for shorter gate lengths helping to satisfy the space/density requirement. The novel channel materials, allow for aggressive reduction of the power supply voltage without performance loss due to amazingly higher mobility of the carriers over Silicon. Materials that are under investigation include: III-V compound semiconductors, and Carbon allotropes at low quantum mechanical confinement dimensions, specifically 2-D sheet of monolayer Graphene and single-walled Carbon nanotube wires.
- ItemHow to Build a Tech Business From Scratch(2012-03-26) Dr. Justin Beck
Bootstrapping is not for the faint of heart. These brave entrepreneurs must make decisions every day that directly affect the success of their startup. In this lecture, Justin Beck will talk about the ups and downs he faced bootstrapping his mobile and social gaming startup, PerBlue. From the early days in college to a successful high growth company today, Justin will tell the important lessons he learned along the way. During the lecture Justin will cover the major challenges he faced, like why he turned down a high paying job at Microsoft to work 100+ hours a week in his college apartment. He’ll talk about recruiting friends to PerBlue, and how he compensated them with zero budget. This lecture will cover raising funds, and making the most out of very little capital.
Finally, Justin will talk about Parallel Kingdom’s revenue model, and how it allowed PerBlue to grow a team of five employees to over thirty five in just three years. - ItemAg//Au Solar Converters(2012-03-26) Madleen A. Al-Balshi; A. F. Qasrawi; N. M. Gasanly
A new type of solar cells which are designed from single crystals using silver and gold metals to construct point contacted photocells are reported and discussed. The influence of the driving electric field on the performance of the device was tested. The current density-electric field dependence curve reflected a space charge limited photocurrent effect being dominant in the filed region of 1-4.3 V/cm. In addition, the solar cell short circuit and loaded current dependence on the excitation intensity was measured. The short circuit current is observed to exhibit exponential trap distribution effect and supralinear recombination at low and high illumination intensities, respectively. The device displays a current density of 0.5 (mA/cm2) for excitation intensity of 76 klux. When loaded it displayed a stable power dissipation curve. Such behavior reflects the novelty of these types of cells for future application. PACS: 71.55.Ht, 72.20.Dp, 72.20.Jv, 72.40.+w, 72.80.Jc, 78.20.Ci
- ItemDiameter Dependence Of Structural And Electronically Properties Of Gaas, Gap And Their Alloys Nanowires(2012-03-26) Dr. Rezek Esteteh
Using abintio methods, we study the formation energies and the electronic structure of GaAs, GaP and their alloys (GaAsxP1-x ) , GaAs and GaP bulk materials has zinc- blende (ZB) structure, but the ground state of nanowires may be either ZB or wurtzite (WZ), depending on energy contribution from their surfaces and edges. The calculated nanowires in this work are cut from the bulk material in the [111] direction and [0001] direction for ZB and WZ structure, respectively. It’s found that the WZ formation energy is lower than the ZB formation energy, regardless of the hydrogenation of the surface bonds. In the present work, the energy gap has been calculated with respect to full range of concentration for the alloys.
- ItemTowards a Knowledge Based Economy in Palestine Nano or Not: Technology is the Answer(2012-03-26) Reyad I. Sawafta
The world’s population has exceeded 7 billion in the year 2011 and continues to grow by 83 million people per year to reach an estimated 9 billion in 2050. The quest for safe, secure and sustainable sources to meet the need for those billions poses one of the most critical challenges of our time. Our Civilization will be seeking food, water, energy and other resources on a planet where humans are already shaping the web of life. The increasing demand for these resources drives research in academic and industrial institutions in order to discover new ways to produce fresh and safe drinking water, extract energy from renewable sources, and to develop more efficient and affordable products and practices.
Innovative research and novel technologies are the catalysts for the acceleration of growth in knowledge-based economies, which provide developing countries big opportunities to compete with those that are already developed. To play in the knowledge based economy league, Palestinian policymakers must pave the way for the next economic engines by spear-heading the shift to a knowledge-based economy. People’s education must be the highest priority starting at the elementary school level and going all the way to the university undergraduate and graduate levels. We must prepare the current and future generations of our students to lead the way towards a better future for our people.
Academic and industrial professionals have to lead the change; the status quo cannot be maintained. Academics have to liberate themselves from their self-imposed confinement. As much as we need specialized scientific research in the fields of physics, chemistry, biology, nutrition, agriculture, medicine and many other disciplines we must regroup in the world of multidisciplinary science and technology and work in teams. Artificial barriers and walls that exist between specialized units at academic.
Institutions must be removed; the challenges that face the Palestinian nation are too complex to be addressed by individual researchers or individual disciplines. The future economy has no room for ego and cannot tolerate ignorance, tardiness and incompetence. Albert Einstein once said: “Insanity is doing the same thing over and over again and expecting different results;” we must progress.
Despite the fact that Industrial institutions do not have the same brain power or the inventive capacities of academic institutions, they are often more disciplined in approaching problems and coming up with solutions within tough constraints. This is due to the fact that their own existence is threatened should they fail to reach productivity and profitability within certain timelines. A knowledge based economy integrates the brain power of academia with the efficiency and business skills of industry, and fuels this integral with every available resource from government, foundations and people. The result is a transformation of information into knowledge; leading to advanced technology, efficient production and job creation- all of which provide the cornerstones for a prosperous future for the nation as a whole.
A critical mass of young established Palestinian researchers must be brought together by building bridges at the national, regional and global levels to shed light on these issues and to develop policy recommendations. In the meantime, we do not need to reinvent the wheel, but rather we can learn from the experience of others. Developed countries have spent hundreds of billions of dollars to develop advances in medicine, engineering, material science, nanotechnology, biotechnology, telecommunication and advanced electronics. We must use this wealth of accumulated knowledge as a starting point for future development of innovations- providing fresh and safe drinking water to our people, developing efficient renewable energy sources, as well as preventing and curing common diseases that are striking our region. Social networks have to be employed in our future efforts to document and collect needed knowledge from various media sources, to create collaborations at all levels and to build connectivity between philanthropists, researchers, policy makers, manufacturers and consumers. The effectiveness of social networks have been demonstrated in the past year in promoting democracy and breaking the fear factor among the young generations in the Arab World. The same tools can be used to break the fears of re- searchers, help promote their confidence and provide them with the necessary tools to achieve the goals of their scientific research. Social networks can also be used to raise the awareness of the people and help in making them active partners in building the future of the next generations.
In this presentation, we will present affordable and novel examples, approaches, and recommendations for professors, researchers, students, entrepreneurs, philanthropists and policy makers that can be implemented to provide innovative solutions to existing water, energy, food and health challenges facing the region in general, and Palestine in particular. - ItemNanoindentation and Tensile Testing of Nylons Blends Nanocomposites(2012-03-26) Rabab Jarrar; Yousef Haik
Nylon 6 ,Nylon 6.6 and their blends: ((30% nylon6:70% nylon 6.6), (50% nylon6:50% nylon 6.6) and (70% nylon6:30% nylon 6.6)) at different clay loadings were prepared by mixing the polymers with 1.34TC nanoclay which is an organic modified clay to be compatible with the polymer matrix (nylons) and by heat and melt injection the nanocomposites were prepared. Tensile test and nanoindentation test were performed to investigate the effect of blending process as well as the effect of the incorporated clay on the mechanical properties. An enhancement in the Young’s modulus after the addition of the nanoclay was obtained for all the nanocomposites but the amount of increase differs from one composite to other having its greatest value for nylon 6 after the addition of 6% nanoclay by weight with an increase of nearly 55% above its original value. While the effect of the addition of nanoclay on the tensile strength depends on the blend ratio of the composite having its greatest effect on the (50% nylon6:50% nylon6.6) blend with an increase of an amount of 44%, 59% for 2% , 4% clay loading respectively and the blend exhibited ductile behavior at 2% clay loading The reduced modulus and the young’s modulus obtained from the nanoindentation test have the same trend as the one obtained from the tensile test but with greater values and hard- ness increases for nearly all the composites by the addition of the nanoclay.
- ItemNF-B-Dependent Prevention of Atherosclerotic Foam Cell Formation and Ves- Sel Plaque Accumulation by Fullerene-Based Nanomedicines(2012-03-26) Anthony L. Dellinger, BS; Zhiguo Zhou, PhD; Marinella Sandros, PhD; Ashraf Sawafta, PhD; Patty Elkins, MS; Christopher L. Kepley, PhD
Fullerenes are carbon spheres that have been shown to have anti-inflammatory properties. The transformation of monocytes into foam cells is an inflammatory process underlying atherosclerotic disease. We hypothesized that fullerene derivatives (FD) could inhibit the monocyte-to-foam cell transformation step involved in atherosclerosis. Fullerene derivatives inhibited the phorbol myristilic acid/oxidized low-density lipoprotein differentiation of monocytic U937 cells into foam cells as determined by lipid staining, cell adhesion, and scanning electron microscopy. Oxidized low density lipoprotein-induced generation of TNF-α, leukocyte integrin Mac-1-driven cell clumping, and CD36 receptor expression were significantly inhibited in FD treated cells com- pared to non-treated cells. For the first time it is shown that FD can dramatically reduce NF-κB expression in the oxidized low-density lipoprotein-dependent transformation of macrophages into foam cells. Apolipoprotein E knockout mice (ApoE -/-) fed a high fat diet (HFD) had dramatic inhibition of plaque formation in the blood vessels when treated with FD compared to non-treated controls. Lastly, no in vitro or in vivo toxic- ity was detected with FD; instead the FD helped reduced liver toxicity associated with the HFD. Thus, FD may be a heretofore unrecognized way to prevent atherosclerotic lesions through the inhibition of foam cell formation.
- ItemMultifunctional Nanovehicles for Combined 5-Fluorouracil and Gold Nanoparticles Based on the Nanoprecipitation Method(2012-03-26) Abeer Karmi; Ghaleb A. Husseini; Maryam Faroun; Mukhles Sowwan
To facilitate the administration of combined 5-Fluorouracil (5-FU) and gold nanoparticles (for photothermal treatment purposes), we developed 5-FU-gold poly (lactide-co- glycolic acid) (5-FU-Au- PLGA) nanovehicles, via the nanoprecipitation method. The gold nanoparticles were incorporated inside the 5-FU-PLGA carriers using a roller mixer. Morphological analysis using atomic force microscopy (AFM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), indicated uniform, singly separated spherical nanoparticles (NPs). Drug content, recovery and entrapment in the NPs were approximated using UV-spectrophotometer data. Approximately 26% of nanoparticles were recovered after drying. The percentage of total drug content was about 30%, and the percentage of drug entrapment reached 57%. Electrostatic Force Microscopy images confirmed the presence of gold inside the drug-loaded nanoparticles. We speculate that the 20-nm gold particles were able to diffuse, after 12 hours of mixing (using the roller mixer), into the PLGA matrix through the 100-nm pores (observed by SEM) without affecting the integrity of the drug delivery vehicle. These synthesized nanoparticles show promise as multimodal vehicles in the delivery of chemotherapeutic agents.
Keywords: Drug Delivery, 5-Fluorouracil, PLGA, Nanoprecipitation Method, Gold Nanoparticles. Key points in the research paper:
1. We developed multifunctional nanovehicles for combined chemotherapy and photothermal treatment, based on a biodegradable and biocompitable polymer.
2. A synergistic effect of the chemotherapy induced by 5- fluorouracil coupled with the hyperthermia induced by the gold nanoparticles have the potential to increase the efficacy of these newly synthesized PLGA nanocarriers and may allow for decreasing the amount of the 5-FU administered to patient which in turn would reduce its cytotoxicity and side effects.
3. We have examined the feasibility of using this novel drug delivery system in vitro. To our knowledge, we are the first group to use EFM to study metallic nanoparticles incorporation inside polymer carriers. Additionally, while previous researchers have reported the deposition of gold on the surface of PLGA nanocarriers, here we show the presence of gold nanoparticles inside the PLGA matrix. - ItemNanotechnology For Plant Pathogen Control(2012-03-26) Mazen Salman
Plant pathogens and pests are of the major factors limiting crop productivity. In crop sciences, nanotechnology can be used for the production of nanocapsules for delivery of pesticides, fertilizers, and other agrochemicals (Jha et al 2011). Nanotechnology for the control of plant diseases is a promising technique in plant pathology either by providing controlled delivery of functional molecules or as diagnostic tool for disease detection, an important step in plant disease treatment (Sharon et al 2010).Encapsulation of herbicides could provide improvement in their application. For example Sulfonylurea herbicides are applied through the soil to control Orobanchespp., but several applications are needed to achieve effective control (Joel et al 2007). Several studies were conducted using Nanosized particles to control fungal pathogens including such as Pythiumultimum,Magnaporthegrisea, Colletotrichum, gloeosporioides, Botrytis cinereand, Rhyzoctoniasolani, as well as bacterial disease including Bacillus subtilis, Azotobacterchrococuum, Rhizobium tropici, Pseudomonas syringaeandXanthomonascompestrispv. Vesicatoria (Park et al 2006). In Palestine, nanotechnology might be used for the control of several plant pathogens such as powdery mildews on grapevine and olive leaf spot on olive trees. We are interested in using nanosized silica particles and nanocapsules for the control of these diseases. In addition to that incorporation of nanoparticles for formulation and application of bacteria as bioconrtol agents against soil borne pathogens will tested.
References
1. Jha Z., Behar N., Sharma S. N., Chandel G., Sharma D.K. And Pandey M.P. (2011). Nanotech- nology: Prospects of Agricultural Advancement. Nano Vision, (2), 88-100
2. JoelD. M., HershenhornJ., Eizenberg H.,AlyR.,EjetaG.,RichP. J.,RansomJ. K., SauerbornJ. and RubialesD. (2007).Biology and management of weedy root parasites. Horticulture Reviews 33:267–349.
3. Park1 H., Kim S. H., Kim H. J. and Choi S. (2006).A New Composition of Nanosized Silica- Silver for Control of Various PlantDiseases.Plant Pathology Journal, 22(3): 295-302
4. Sharon1 M., Kr. Choudhary A. and Rohit K. (2010). Review article nanotechnology in agricultural diseases and food safety. Journal of Phytology, 2(4): 83–92 - ItemMagnetic Nanomembranes(2012-03-26) Denys Makarov
In our everyday life, we are surrounded by electronic sensing devices designed in a way to meet requirements for a certain application, which is determined primarily by their shape and size. In this respect, the natural question, which surprisingly has only recently been raised, is can one create electronics that can be reshaped on demand after its fabrication? After introducing this ground-breaking paradigm, the so-called flexible electronics became a dynamically developing research area with al- ready a variety of flexible devices commercially available: electronic displays, light-emitting diodes, integrated circuitry, to name a few. Special attention has been paid to the family of stretchable electronics which combines advantages of being flexible with the high speed of conventional semiconductor-based electronics. Until recently, the main focus was on fabrication of shapeable high-speed electronics [1] and optoelectronics [2]. However, the family of stretchable electronics is not limited to these two members. Only very recently, we reported for the first time the fabrication of stretchable magnetoelectronics [3, 4]. In this talk I will focus on fabrication of stretchable magnetoelectronics and on its various application aspects. Due to their flexibility and stretchability, these devices are unique as the same initial sensor can be used for multiple purposes: an elastic magnetic sensor integrated in a fluidic tubing can be applied for therapeutic purposes [5]. Alternatively, the same sensor can be mounted on a curved surface of a stator in a tiny gap between rotor and stator in electrical machines to provide a regulation for the rotor position. Due to the low price of elastic polymeric substrates which can be used, shape- able magnetic sensors are much cheaper compared to their rigid semiconductor-based counterparts, thus opening the door for large area sensor fabrication, which is a break-through in conventional sensor engineering.
[1] D. H. Kim et al., Nature Mater. 10, 316 (2011).
[2] R. H. Kim et al., Nature Mater. 9, 929 (2010).
[3] M. Melzer et al., Nano Letters 11, 2522 (2011).
[4] I. Mönch et al., ACS Nano 5, 7436 (2011). [5] M. Melzer et al., RSC Adv. DOI: 10.1039/C2RA01062C (2012). - ItemNanoparticles for Molecular Imaging of Cancer(2012-03-26) Bulent Aydogan
Functional CT technique offers a new set of capabilities in cancer imaging by providing unmatched high-resolution anatomic and functional images in a single CT scan. However, due to lack of suitable contrast agents, functional CT imaging of cancer has not been successful. We investigate the feasibility of using 2-Deoxy-D-Glucose (2-DG) labeled gold nanoparticle (AuNP-2-DG) as functionally targeted CT contrast agent to obtain high resolution metabolic and anatomic information of tumors in a single CT scan. Gold nanoparticles (AuNP) were fabricated and conjugated with 1- or 2-Deoxy-D-Glucose. 1-DG provides an excellent comparison since it is known to interfere with the ability of the glucose transporter to recognize the sugar moiety. The human alveolar epithelial cancer cell line, A-549, was chosen for the in vitro cellular uptake assay. Three groups of cell samples were incubated with the 1-DG or 2-DG labeled AuNP and the unlabeled AuNP. The cell pellets were imaged using a microCT scanner immediately after the centrifugation. Internalization of AuNP-2-DG is verified using Transmission Electron Microscopy imaging. Three to four fold contrast enhancement was observed in the cell samples incubated with the AuNP-2-DG with respect to the cell samples incubated with the unlabeled AuNP and the AuNP-1-DG. In addition, our preliminary in vivo experiments were very encouraging. Results from our in vitro and preliminary in vivo experiments suggest that AuNP-2-DG may be used as a functional CT contrast agent to provide high-resolution metabolic and anatomic information in a single CT scan. Successful clinical implementation of this technique may be expected to greatly improve the accuracy of target definition and radiation delivery in modern radiotherapy.
ACKNOWLEDGMENTS:
This work was partially supported by Research Training in Medical Physics 5 T32-EB002103-19 and ACS, Illinois 160356. Use of the Center for Nanoscale Materials at Argonne National Laboratory was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Science, under Contract No. DE-AC02-06CH11357.
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