521 research outputs found
Logixpro Based Scada Simlations Model for Packaging System in Dry ICE Plant
Supervisory Control and Data Acquisition (SCADA) systems control and monitor industrial and critical infrastructure functions, such as electricity, gas, water, waste, railway, and traffic. The main objective of this work is to develop SCADA simulation model for packaging system in dry ice plant. Dry ice is an important refrigerant for keeping foods cold and preventing bacterial growth during shipment. Dry ice used for cooling or freezing foods must be very clean and considered food grade to ensure that food it may touch will not be contaminated. Some recent developments for its use include using the pellets in blasting or cleaning and its increasing use in transporting medical specimens, including hearts, limbs, and tissues, for reattachment and transplantation. The manufacturing process of dry ice has not changed significantly in many decades and is a relatively simple process of pressurizing and cooling gaseous carbon dioxide. But because of its growing demand, packaging becomes vital. An attempt has been made to develop and automate LOGIXPRO based SCADA simulations for dry ice plant to improve packaging and extensively reduce operating labor costs
A Novel Method to Monitor Sequential Displacement of Capped Ligands in Gold Nanoparticles [abstract]
Nanoscience Poster SessionNanochemistry of ligand displacement reactions has attracted much attention in recent years for the development of myriad of new gold nanomaterials. Gold nanoparticles have shown applications ranging from tumor imaging agent in nanomedicine to single electron devices in information technology. New gold materials are synthesized by exchange of neutral or anionic ligands with thiolated molecules. Completion of ligand substitution reactions in gold nanoparticles are monitored by using UV-Vis spectrometry. However, there are no methods available to monitor the sequence of the ligand substitution reactions. Monitoring and predicting the sequence of ligand substitutions would provide a convenient handle for the design and development of hybrid nanomaterials containing two or more ligands. In this context, we have developed a novel technique utilizing disc centrifuge systems to monitor the sequential displacement of ligands in various gold nanoconstructs. In our studies, we have used gold nanoparticles stabilized with both anionic and neutral ligands. Gold nanoparticles of various different substitutions have been identified and characterized by disc centrifuge systems. Details of substitution reactions and mechanism on monitoring the sequential displacement using strong ligands will be presented
Nanomedicine approach for sustained release delivery of Avastin : treatment for PXE and AMD [abstract]
Gold nanoparticles possess unique properties including preferential binding to leaky blood vessels, ability to bind to a variety of ligands, with no evidence of cellular toxicity, making them an excellent platform for targeted sustained release of drugs. Avastin (Bevacizumab) is a humanized monoclonal antibody specifically targeting vascular endothelial growth factor (VEGF) that has found widespread use in inhibiting intraocular neovascularization manifested in macular degeneration and proliferative diabetic retinopathy. The conjugation of gold nanoparticles (AuNP) with Avastin (Av) yields AvAuNP nanoconjugates. Avastin conjugated gold nanoparticles (AvAuNP) can be used as therapeutic agents in the treatment of ophthalmic neovascular disorders, such as macular degeneration, PXE and proliferative diabetic retinopathy. AvAuNP nanoconjugate is a potential clinical therapeutic agent and has demonstrated excellent ability to deliver Avastin for sustained release of therapeutic dose within the eye. The design and development of AvAuNP conjugate would help in the initiation and completion of preclinical evaluations aimed at determining the ability to achieve long-term suppression of intraocular neovascularization in large animals. INVENTOR(S): Ravi Shukla; Kavita K. Katti; Raghuraman Kannan; Dean Hainsworth and Kattesh V. Katti CONTACT INFO: Paul Hippenmeyer, Ph.D., M.B.A.; [email protected]; (573)-882-047
Rif1 controls DNA replication by directing Protein Phosphatase 1 to reverse Cdc7-mediated phosphorylation of the MCM complex
Peer reviewedPublisher PD
Agarose-stabilized gold nanoparticles for surface-enhanced Raman spectroscopic detection of DNA nucleosides
doi:10.1063/1.2192573 http://scitation.aip.org/getpdf/servlet/GetPDFServlet?filetype=pdf&id=APPLAB000088000015153114000001&idtype=cvips&prog=normal&doi=10.1063/1.2192573We present surface-enhanced Raman scattering (SERS) studies of DNA nucleosides using biologically benign agarose-stabilized gold nanoparticles (AAuNP). We compare the SERS activity of nucleosides with AAuNP to that of commercially obtained citrate-stabilized gold nanoparticles and find the SERS activity to be an order of magnitude higher with AAuNP. The higher SERS activity is explained in terms of the agarose matrix, which provides pathways for the gold nanoparticles to have distinct arrangements that result in stronger internal plasmon resonances.This work was supported through the University of Missouri Research Board grants URB04-023 (S.G.) and URB03-080 (M.C. and K.V.K.), NSF under Grant No. DMR-0413601and the NCI under Grant No. IR0ICA119412-01. The gold nanoparticles were produced and supplied by the University of Missouri Nanoparticle Production Core Facility
Free energy barrier for melittin reorientation from a membrane-bound state to a transmembrane state
An important step in a phospholipid membrane pore formation by melittin
antimicrobial peptide is a reorientation of the peptide from a surface into a
transmembrane conformation. In this work we perform umbrella sampling
simulations to calculate the potential of mean force (PMF) for the
reorientation of melittin from a surface-bound state to a transmembrane state
and provide a molecular level insight into understanding peptide and lipid
properties that influence the existence of the free energy barrier. The PMFs
were calculated for a peptide to lipid (P/L) ratio of 1/128 and 4/128. We
observe that the free energy barrier is reduced when the P/L ratio increased.
In addition, we study the cooperative effect; specifically we investigate if
the barrier is smaller for a second melittin reorientation, given that another
neighboring melittin was already in the transmembrane state. We observe that
indeed the barrier of the PMF curve is reduced in this case, thus confirming
the presence of a cooperative effect
Replication Stress-Induced Chromosome Breakage Is Correlated with Replication Fork Progression and Is Preceded by Single-Stranded DNA Formation
Chromosome breakage as a result of replication stress has been hypothesized to be the direct consequence of defective replication fork progression, or “collapsed” replication forks. However, direct and genome-wide evidence that collapsed replication forks give rise to chromosome breakage is still lacking. Previously we showed that a yeast replication checkpoint mutant mec1-1, after transient exposure to replication impediment imposed by hydroxyurea (HU), failed to complete DNA replication, accumulated single-stranded DNA (ssDNA) at the replication forks, and fragmented its chromosomes. In this study, by following replication fork progression genome-wide via ssDNA detection and by direct mapping of chromosome breakage after HU exposure, we have tested the hypothesis that the chromosome breakage in mec1 cells occurs at collapsed replication forks. We demonstrate that sites of chromosome breakage indeed correlate with replication fork locations. Moreover, ssDNA can be detected prior to chromosome breakage, suggesting that ssDNA accumulation is the common precursor to double strand breaks at collapsed replication forks
Green nanotechnology from cumin phytochemicals : generation of biocompatible gold nanoparticles
Published in final edited form as:
Int J Green Nanotechnol Biomed. 2009 January 1; 1(1): B39-B52. doi:10.1080/19430850902931599.The powerful antioxidant characteristics of various phytochernicals within cumin prompted us to test their efficacy in reducing sodium tetrachloroaurate to corresponding gold nanoparticles. We, herein, report an unprecedented synthetic route that involves the production of well-defined spherical gold nanoparticles by simple mixing of cumin to an aqueous solution of sodium tetrachloro aurate. Production of gold nanoparticles in this cumin-mediated Green Nanotechnological process is achieved under biologically benign conditions. The gold nanoparticles generated through cumin-mediated process did not aggregate suggesting that the cocktail of phytochemicals including proteins serve as excellent coatings on nanoparticles and thus, provide robust shielding from aggregations. In addition, the phytochemical coatings on nanoparticles have rendered nontoxic features to these 'Green Gold Nanoparticles' as demonstrated through detailed MTT assays performed on 'normal fibroblast cells. Results of our studies presenting a new 'Nano-Naturo' connection for the production and utility of gold nanoparticles for potential applications in nanomedicine and nanotechnology are discussed in this paper.This work has been supported by the generous support from the National Institutes of Health/National Cancer Institute under the Cancer Nanotechnology Platform program (grant number: 5R01CA119412-01), NIH - 1R21CA128460-01 and University of Missouri-Research Board - Program C8761 RB 06-030
The effect of Ku on telomere replication time is mediated by telomere length but is independent of histone tail acetylation
Peer reviewedPublisher PD
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