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Search Results: 1 - 10 of 401375 matches for " Benton Shana M "
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Differential regulation of tissue thiol-disulfide redox status in a murine model of peritonitis
Benton Shana M,Liang Zhe,Hao Li,Liang Youngliang
Journal of Inflammation , 2012, DOI: 10.1186/1476-9255-9-36
Abstract: Background Glutathione (GSH)/glutathione disulfide (GSSG) and cysteine (Cys)/cystine (CySS) are major redox pools with important roles in cytoprotection. We determined the impact of septic peritonitis on thiol-disulfide redox status in mice. Methods FVB/N mice (6–12 week old; 8/group) underwent laparotomy with cecal ligation and puncture (CLP) or laparotomy alone (control). Sections of ileum, colon, lung and liver were obtained and GSH, GSSG, Cys and CySS concentrations determined by HPLC 24 h after laparotomy. Redox potential [Eh in millivolts (mV)] of the GSH/GSSG and Cys/CySS pools was calculated using the Nernst equation. Data were analyzed by ANOVA (mean ± SE). Results GSH/GSSG Eh in ileum, colon, and liver was significantly oxidized in septic mice versus control mice (ileum: septic 202±4 versus control 228±2 mV; colon: -195±8 versus 214±1 mV; and liver: -194±3 vs. -210±1 mV, all P<0.01). Lung GSH/GSSG redox was similar in each group ( 191±3 versus 190±2 mV). In contrast, ileal and colonic Cys/CySS Eh was unchanged with CLP, while liver and lung Cys/CySS Eh became significantly more reducing (liver: septic = 103±3 versus control 90±2 mV; lung: -101±5 versus 81±1 mV, each P<0.05). Conclusions Septic peritonitis induced by CLP oxidizes ileal and colonic GSH/GSSG redox but Cys/CySS Eh remains unchanged in these intestinal tissues. In liver, CLP oxidizes the GSH/GSSG redox pool and CyS/CySS Eh becomes more reducing; in lung, CLP does not alter GSH/GSSG Eh, and Cys/CySS Eh is less oxidized. CLP-induced infection/inflammation differentially regulates major thiol-disulfide redox pools in this murine model.
Photonic Processing for Wideband Cancellation and Spectral Discrimination of RF Signals
David M. Benton
Advances in Optical Technologies , 2013, DOI: 10.1155/2013/738427
Abstract: Photonic signal processing is used to implement common mode signal cancellation across a very wide bandwidth utilising phase modulation of radio frequency (RF) signals onto a narrow linewidth laser carrier. RF spectra were observed using narrow-band, tunable optical filtering using a scanning Fabry Perot etalon. Thus functions conventionally performed using digital signal processing techniques in the electronic domain have been replaced by analog techniques in the photonic domain. This technique was able to observe simultaneous cancellation of signals across a bandwidth of 1400?MHz, limited only by the free spectral range of the etalon. 1. Introduction Photonic signal processing offers a new paradigm for processing high bandwidth signals and opens up possibilities for directly processing signals that are modulated onto an optical carrier. The ability to process and manipulate ultrawideband signals enables high-resolution, reconfigurable processing of potentially the entire RF spectrum of signals. It is this potential that has received a lot of attention over the past few decades [1, 2] and is suitably demonstrated through devices such as wideband adaptive microwave filters enabled through coherence and phase control [3]. Photonic technologies are a natural source for delivering increased bandwidth, but also the low loss of fibre optic transmission systems has seen developments in transmitting Radio over Fibre (RoF) and antenna remoting [4, 5]. As requirements for increased data bandwidth develop and as spectral densities increase, with congestion becoming an issue, the need for ever more powerful digital signal processing (DSP) is a constant driver. This has inevitable consequences for size, weight, and power (SWaP) considerations, especially in RF signal monitoring and characterisation equipment. With the RF signal in photonic form and the inherent bandwidth benefits that ensue, there is a natural opportunity for implementing analog signal processing (ASP) techniques and making the processing an inherent part of the optical link [6]. Signal cancellation is conventionally implemented by engineering a version of the target waveform that is matched in amplitude but 180° out of phase (negative feedback) such that the interference of the target and engineered waveforms result in cancellation. This approach can be performed with analog or digital signals but is likely to be limited in its operational bandwidth by frequency dependent phase shifts. Photonic carriers modulated by RF signals are not limited by these frequency dependent phase shifts in circuitry
Identification of Asbestos Using Laser-Induced Breakdown Spectroscopy: A Viable Alternative to the Conventional Approach?
David M. Benton
ISRN Spectroscopy , 2013, DOI: 10.1155/2013/362694
Abstract: Laser-induced breakdown spectroscopy has been performed on isolated samples of six types of asbestos—Chrysotile, Crocidolite, Amosite, Anthophyllite, Actinolite, and Tremolite—with analysis of optical emission in the visible region of the spectrum. The principal elements of Mg, Fe, Si, Na, and Ca have all been identified. By examining peak intensity ratios of these elements it is possible to identify the type of asbestos under examination solely from internal examination of the sample spectra. LIBS offers some significant advantages of speed of analysis and removal of subjectivity with potential for on-site rapid analysis. 1. Introduction Asbestos has been widely used, particularly in the construction industry, because of its strength, flexibility, and resistance to chemical and thermal breakdown. It is now known that inhalation of high levels of asbestos can lead to increased risk of asbestosis, lung cancer, and mesothelioma [1]. Asbestos is considered a hazard to health and its use is positively discouraged. Nevertheless some 15,000 tons were used in the USA in 1999, and it is still in widespread use around the world. Several well-established methods are currently available for identifying asbestos; these are transmission electron microscopy (TEM), scanning electron microscopy (SEM), and polarised light microscopy (PLM). Of these techniques PLM is the most widely used for reasons of cost and speed. The current method of assessing asbestos involves surveying a building for potential materials containing asbestos, taking several small samples and then sending them to a laboratory for analysis. Suspect fibres are manually extracted from the sample and examined using PLM. An assessment of the nature of the fibre is made according to fibre morphology, refractive index, and birefringence. This technique is usually sufficient to determine that the fibre is asbestos and identify its type. However, the process can be time consuming, labour intensive and relies on a potentially subjective assessment of what type of asbestos the fibre is likely to be (influencing the choice of refractive index matching fluid). Certain other fibres such as polyethylene, spider’s web, and several other organic materials can sometimes be mistaken for asbestos using this process unless great care and experience are used in the assessment. If, after completing the above process, the assessment is still not clear SEM can be used and the fibre’s elemental composition can be determined. The ratio of the elements calcium, sodium, iron, and magnesium is a confirmation of the specific type
Concurrent codes: A holographic-type encoding robust against noise and loss
David M. Benton
Mathematics , 2015,
Abstract: Concurrent coding is an encoding scheme with "holographic" type properties that are shown here to be robust against a significant amount of noise and signal loss. This single encoding scheme is able to correct for random errors and burst errors simultaneously, but does not rely on cyclic codes. A simple and practical scheme has been tested that displays perfect decoding when the signal to noise ratio is of order -18dB. The same scheme also displays perfect reconstruction when a contiguous block of 40% of the transmission is missing. In addition this scheme is 50% more efficient in terms of transmitted power requirements than equivalent cyclic codes. A simple model is presented that describes the process of decoding and can determine the computational load that would be expected, as well as describing the critical levels of noise and missing data at which false messages begin to be generated.
Use of Early Goal-Directed Therapy in the Emergency Department before and after the Sepsis Trilogy  [PDF]
Loren K. Reed, Benton R. Hunter, Tyler M. Stepsis
Open Journal of Emergency Medicine (OJEM) , 2016, DOI: 10.4236/ojem.2016.42005
Abstract: The management of sepsis evolved recently with the publication of three large trials (referred to as the sepsis trilogy) investigating the efficacy of early goal-directed therapy (EGDT). Our goal was to determine if the publication of these trials has influenced the use of EGDT when caring for patients with severe sepsis and septic shock in the emergency department (ED). In February 2014, we surveyed a sample of board-certified emergency medicine physicians regarding their use of EGDT in the ED. A follow-up survey was sent after the publication of the sepsis trilogy. Data was analyzed using 95% confidence intervals to determine if there was a change in the use of EGDT following the publication of the above trials. Subgroup analyses were also performed with regard to academic affiliation and emergency department volume. Surveys were sent to 308 and 350 physicians in the pre-and post-publication periods, respectively. Overall, ED use of EGDT did not change with publication of the sepsis trilogy, 48.7% (CI 39.3% - 58.2%) before and 50.5% (CI 40.6% - 60.3%) after. Subgroup analysis revealed that academic-affiliated EDs significantly decreased EGDT use following the sepsis trilogy while nonacademic departments significantly increased EGDT use. Use of EGDT was significantly greater in community departments versus academic departments following the publication of the sepsis trilogy. There was no change overall in the use of EGDT protocols when caring for patients with severe sepsis and septic shock, but subgroup analyses revealed that academic departments decreased their use of EGDT while community departments increased use of EGDT. This may be due to varying rates of uptake of the medical literature between academic and community healthcare systems.
Planting Date, Seeding Rate, and Cultivar Impact Agronomic Traits and Semolina of Durum Wheat  [PDF]
Shana M. Forster, Joel K. Ransom, Frank A. Manthey, John R. Rickertsen, Grant H. Mehring
American Journal of Plant Sciences (AJPS) , 2017, DOI: 10.4236/ajps.2017.89137
Abstract: Durum wheat (Triticum durum Desf.) is a market class of wheat subject to price discounts in the marketplace if quality standards are not met. This study was conducted in order to determine how certain agronomic practices might impact durum wheat quality. The effects of planting date (PD), cultivar, and seeding rate on agronomic and semolina quality traits were investigated in field trials conducted near Hettinger and Minot, ND in 2014 and 2015. The interaction of PD and cultivar was significant for many of the traits evaluated. There was a significant PD X cultivar interaction or PD and cultivar effect for yield in all environments. Planting date X cultivar interacted for test weight at all environments. In general, a delay in PD resulted in a significant decrease in yield and test weight for all cultivars. However, Carpio yielded more than other cultivars in high yielding environments while the yield and test weight of Joppa was more adversely affected by delays in PD. Seeding rate did not have a consistent effect on any agronomic or quality trait. Protein content, kernel yellow pigment content, falling number (FN), and vitreous kernels were more dependent on cultivar, regardless of PD and environment. Semolina extraction, gluten index (GI), and wet gluten (WG) values tended to decrease with a delay in PD. These data continue to support cultivar selection as a critical component for obtaining high-yielding, high-quality durum wheat. However, PD and environment can impact certain agronomic and end-use traits, regardless of cultivar grown.
Breaking the Adhesive Bond between Dialyll Phthlate, Barco Bond 185 and PBX 9501  [PDF]
Matt Jackson, Benton Allen, Trent Kelly, Courtney Waddell, Emily M. Hunt, Stephanie Steelman, Neil Koone
Journal of Materials Science and Chemical Engineering (MSCE) , 2015, DOI: 10.4236/msce.2015.37026
Abstract:

Use of epoxy as an adhesive is a common practice. The most common applications are permanent sealants. Epoxies have a wide range of operating temperatures, and are very resistance to adhesive failure. When a need to remove this adhesive arises, it is not always easily accomplished especially if the part has excessive adhesive. To maintain fidelity of the parts attached by epoxy, a project evaluating several methods of epoxy removal was conducted. Methods evaluated included low wavelength, near-ultraviolet radiation, solvent dissolution, and thermal cycling. The UV method failed to demonstrate a repeatable dissociation. The solvent study did result in dissociation of bonds, but introduced chemicals that could make subsequent chemical analysis of parts suspect. Thermal cycling showed a high repeatability for dissociation of bonds and may prove to be relatively inexpensive to implement.

Selective Enrichment of Membrane Proteins by Partition Phase Separation for Proteomic Studies
M. Walid Qoronfleh,Betsy Benton,Ray Ignacio,Barbara Kaboord
Journal of Biomedicine and Biotechnology , 2003, DOI: 10.1155/s1110724303209244
Abstract: The human proteome project will demand faster, easier, and more reliable methods to isolate and purify protein targets. Membrane proteins are the most valuable group of proteins since they are the target for 70–80% of all drugs. Perbio Science has developed a protocol for the quick, easy, and reproducible isolation of integral membrane proteins from eukaryotic cells. This procedure utilizes a proprietary formulation to facilitate cell membrane disruption in a mild, nondenaturing environment and efficiently solubilizes membrane proteins. The technique utilizes a two-phase partitioning system that enables the class separation of hydrophobic and hydrophilic proteins. A variety of protein markers were used to investigate the partitioning efficiency of the membrane protein extraction reagents (Mem-PER) (Mem-PER is a registered trademark of Pierce Biotechnology, Inc) system. These included membrane proteins with one or more transmembrane spanning domains as well as peripheral and cytosolic proteins. Based on densitometry analyses of our Western blots, we obtained excellent solubilization of membrane proteins with less than 10% contamination of the hydrophobic fraction with hydrophilic proteins. Compared to other methodologies for membrane protein solubilization that use time-consuming protocols or expensive and cumbersome instrumentation, the Mem-PER reagents system for eukaryotic membrane protein extraction offers an easy, efficient, and reproducible method to isolate membrane proteins from mammalian and yeast cells.
Epigenetic inactivation and aberrant transcription of CSMD1 in squamous cell carcinoma cell lines
Toni M Richter, Benton D Tong, Steven B Scholnick
Cancer Cell International , 2005, DOI: 10.1186/1475-2867-5-29
Abstract: Only one of the 20 cell lines examined appears to express a structurally normal CSMD1 transcript. The rest express transcripts which either lack internal exons, terminate abnormally or initiate at cryptic promoters. None of these truncated transcripts is predicted to encode a functional CSMD1 protein. Cell lines that express little or no CSMD1 RNA exhibit DNA methylation of a specific region of the CpG island surrounding CSMD1's first exon.Correlating methylation patterns and expression suggests that it is modification of the genomic DNA preceding the first exon that is associated with gene silencing and that methylation of CpG dinucleotides further 3' does not contribute to inactivation of the gene. Taken together, the cell line data suggest that epigenetic silencing and aberrant splicing rather than point mutations may be contributing to the reduction in CSMD1 expression in squamous cancers. These mechanisms can now serve as a focus for further analysis of primary squamous cancers.CUB and Sushi Multiple Domains 1 (CSMD1) was cloned as a candidate tumor suppressor or progression gene from a region of human chromosome 8 deleted in tumors of the upper aerodigestive tract, prostate, ovary and bladder [1-7]. Deletion of 8p23.2 or reduced expression of CSMD1 has been associated with poor prognosis in head and neck squamous cell carcinomas and in prostate cancers [2,5,8].CSMD1, consisting of 70 exons spread over two megabases of 8p23.2, encodes a rare 11.5 kb transcript most abundantly expressed in the brain [1]. It is the founding member of a novel, evolutionarily highly conserved gene family whose proteins contain multiple domains thought to be sites of protein-protein or protein-ligand interactions and whose structure suggests that they may be transmembrane receptors or adhesion proteins [9,10].Tumor suppressor genes are expected to be inactivated in cancers either genetically by mutations or epigenetically by modification of their promoters. While CSMD1 transcripts a
Selective Enrichment of Membrane Proteins by Partition Phase Separation for Proteomic Studies
Qoronfleh M. Walid,Benton Betsy,Ignacio Ray,Kaboord Barbara
Journal of Biomedicine and Biotechnology , 2003,
Abstract: The human proteome project will demand faster, easier, and more reliable methods to isolate and purify protein targets. Membrane proteins are the most valuable group of proteins since they are the target for 70 80% of all drugs. Perbio Science has developed a protocol for the quick, easy, and reproducible isolation of integral membrane proteins from eukaryotic cells. This procedure utilizes a proprietary formulation to facilitate cell membrane disruption in a mild, nondenaturing environment and efficiently solubilizes membrane proteins. The technique utilizes a two-phase partitioning system that enables the class separation of hydrophobic and hydrophilic proteins. A variety of protein markers were used to investigate the partitioning efficiency of the membrane protein extraction reagents (Mem-PER) (Mem-PER is a registered trademark of Pierce Biotechnology, Inc) system. These included membrane proteins with one or more transmembrane spanning domains as well as peripheral and cytosolic proteins. Based on densitometry analyses of our Western blots, we obtained excellent solubilization of membrane proteins with less than 10% contamination of the hydrophobic fraction with hydrophilic proteins. Compared to other methodologies for membrane protein solubilization that use time-consuming protocols or expensive and cumbersome instrumentation, the Mem-PER reagents system for eukaryotic membrane protein extraction offers an easy, efficient, and reproducible method to isolate membrane proteins from mammalian and yeast cells.
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