858 research outputs found
Assessment of tissue fibrosis in skin biopsies from patients with systemic sclerosis employing confocal laser scanning microscopy: an objective outcome measure for clinical trials?
OBJECTIVES: To obtain an objective, unbiased assessment of skin fibrosis in patients with SSc for use in clinical trials of SSc disease-modifying therapeutics.
METHODS: Skin biopsies from the dorsal forearm of six patients with diffuse SSc and six healthy controls, and skin biopsies from the forearm of one patient with diffuse SSc before and following 1 year treatment with mycophenolate mofetil were analysed by confocal laser scanning microscopy (CLSM) with specific antibodies against collagen types I and III or fibronectin. The integrated density of fluorescence (IDF) was calculated employing National Institutes of Health-ImageJ software in at least four different fields per biopsy spanning the full dermal thickness.
RESULTS: The intensities of collagen types I and III and fibronectin IDF were 174, 147 and 139% higher in SSc skin than in normal skin, respectively. All differences were statistically significant. The sum of the IDF values obtained for the three proteins yielded a comprehensive fibrosis score. The average fibrosis score for the six SSc samples was 28.3 x 10(6) compared with 18.6 x 10(6) for the six normal skin samples (P \u3c 0.0001). Comparison of skin biopsies obtained from the same SSc patient before treatment and after 12 months of treatment with mycophenolate mofetil showed a reduction of 39% in total fibrosis score after treatment.
CONCLUSIONS: CLSM followed by quantitative image analysis provides an objective and unbiased assessment of skin fibrosis in SSc and could be a useful end-point for clinical trials with disease-modifying agents to monitor the response or progression of the disease
Electronic control/display interface technology
An effort to produce a representative workstation for the Space Station Data Management Test Bed that provides man/machine interface design options for consolidating, automating, and integrating the space station work station, and hardware/software technology demonstrations of space station applications is discussed. The workstation will emphasize the technologies of advanced graphics engines, advanced display/control medias, image management techniques, multifunction controls, and video disk utilizations
Primer Seminario Iberoamericano de Cuencas de Antepais: Andes, Pirineos y VarĂscides. Proyecto TRANSCUYO
Influence of synthesis conditions on properties of green-reduced graphene oxide
[EN] Green reduction of graphene oxide (GO) was performed using ascorbic acid (AA) in the presence of poly(sodium 4-styrenesulfonate), which resulted in reduced graphene oxide (PSS-rGO) with excellent solubility and stability in water. Large rGO sheets of 4 mu m(2) area and 1.1-nm thickness were obtained. The measurements showed that noncovalent functionalization with PSS molecules prevented rGO from aggregation. The parameters of graphite oxidation process and AA: GO w/w ratio were evaluated, and the obtained results showed that the properties of the reduced material (PSS-rGO) can be tailored by proper selection and adjustment of these parameters.The authors thank the European Commission for their financial support through the project no. NMP3-SL-2010-246073.Pruna, A.; Pullini, D.; Busquets, D. (2013). Influence of synthesis conditions on properties of green-reduced graphene oxide. Journal of Nanoparticle Research. 15(5):1-11. https://doi.org/10.1007/s11051-013-1605-6S111155Acik M, Lee G, Mattevi C et al (2011) The role of oxygen during thermal reduction of graphene oxide studied by infrared absorption spectroscopy. J Phys Chem C 115:1981â19761Akhavan O, Ghaderi E (2012) Escherichia coli bacteria reduce graphene oxide to bactericidal graphene in a self-limiting manner. Carbon 50:1853â1860Akhavan O, Ghaderi E, Esfandiar A (2011) Wrapping bacteria by graphene nanosheets for isolation from environment, reactivation by sonication, and inactivation by near-infrared irradiation. J Phys Chem B 115:6279â6288Akhavan O, Ghaderi E, Aghayee S, Fereydooni Y, Talebi A (2012) The use of a glucose-reduced graphene oxide suspension for photothermal cancer therapy. J Mater Chem 22:13773â13781Bae S, Kim H, Lee Y et al (2010) Roll to- roll production of 30-inch graphene films for transparent electrodes. Nat Nanotechnol 5:574â578Bai H, Xu Y, Zhao L, Li C, Shi G (2009) Non-covalent functionalization of graphene sheets by sulfonated polyaniline. Chem Commun 13:1667â1669Boehm HP (1994) Some aspects of the surface chemistry of carbon blacks and other carbons. Carbon 32:759â769Boukhvalov DW, Katsnelson MI (2008) Modeling of graphite oxide. J Am Chem Soc 130:10697â10701Buchsteiner A, Lerf A, Pieper J (2006) Water dynamics in graphite oxide investigated with neutron scattering. J Phys Chem B 110:22328Choi BG, Park H, Park TJ et al (2010) Solution chemistry of self-assembled graphene nanohybrids for high-performance flexible biosensors. ACS Nano 4:2910â2918Cote LJ, Silva RC, Huang J (2009) Flash reduction and patterning of graphite oxide and its polymer composite. J Am Chem Soc 131:11027â11032Dai B, Fu L, Liao L et al (2011) High-quality single-layer graphene via reparative reduction of graphene oxide. Nano Res 4:434â439Davies MB, Austin J, Partridge DA (1991) Vitamin C: its chemistry and biochemistry. Royal Society of Chemistry, CambridgeElias DC, Nair RR, Mohiuddin TMG, Morozov SV, Blake P, Halsall MP et al (2009) Control of grapheneâs properties by reversible hydrogenation: evidence for graphene. Science 23:610â613Fan FRF, Park S, Zhu Y, Ruoff RS, Bard AJ (2009) Electrogenerated chemiluminescence of partially oxidized highly oriented pyrolytic graphite surfaces and of graphene oxide nanoparticles. J Am Chem Soc 131:937â939Fernandez-Merino MJ, Guardia L, Paredes JI, Villar-Rodil S et al (2010) Vitamin C is an ideal substitute for hydrazine in the reduction of graphene oxide suspensions. J Phys Chem C 114:6426â6432Ferrari AC, Meyer JC, Scardaci V, Casiraghi C, Lazzeri M, Mauri F, Piscanec S, Jiang D, Novoselov KS, Roth S, Geim AK (2006) Raman spectrum of graphene and graphene layers. Phys Rev Lett 97:187401â187405Ganguly A, Sharma S, Papakonstantinou P, Hamilton J (2011) Probing the thermal deoxygenation of graphene oxide using high-resolution in situ X-ray-based spectroscopies. J Phys Chem C 115:17009â17019Hancock RD, Viola R (2005) Biosynthesis and catabolism of l-ascorbic acid in plants. Crit Rev Plant Sci 24:167â188Hernandez Y, Nicolosi V, Lotya M et al (2008) High-yield production of graphene by liquid-phase exfoliation of graphite. Nat Nanotechnol 3:563â568Hontoria-Lucas C, Lopez-Peinado AJ, Loepz-Gonzalez JDD et al (1995) Study of oxygen-containing groups in a series of graphite oxides: physical and chemical characterization. Carbon 33:1585â1592Jeong HK, Lee YP, Lahaye RJWE et al (2008) Evidence of graphitic AB stacking order of graphite oxides. J Am Chem Soc 130:1362â1366Kim KS, Zhao Y, Jang H, Lee SY, Kim JM, Kim KS, Ahn JH, Kim P, Choi JY, Hong BH (2009) Large-scale pattern growth of graphene films for stretchable transparent electrodes. Nature 457:706â710Kuila T, Bose S, Mishra AK, Khanra P, Kim NH, Lee JH (2012) Chemical functionalization of graphene and its applications. Prog Mater Sci 57:1061â1105Kuilla T, Bhadra S, Yao D, Kim NH, Bose S, Lee JH (2010) Recent advances in graphene based polymer composites. Prog Polym Sci 35:1350â1375Kumar P, Subrahmanyam KS, Rao CNR (2011a) Graphene produced by radiation-induced reduction of graphene oxide. Intl J Nanosci 10:559â566Kumar P, Panchakarla LS, Rao CNR (2011b) Laser-induced unzipping of carbon nanotubes to yield graphene nanoribbons. Nanoscale 3:2127â2129Kumar P, Das B, Chitara B et al (2012) Novel radiation induced properties of graphene and related materials. Macromol Chem Phys 213:1146â1163Lee C, Wei X, Kysar JW, Hone J (2008) Measurement of the elastic properties and intrinsic strength of monolayer graphene. Science 321:385â388Li D, Kaner RB (2008) Graphene-based materials. Science 320:1170â1171Li J, Liu CY (2010) Ag/Graphene heterostructures: synthesis, characterization and optical properties. Eur J Inorg Chem 8:1244â1248Li D, Muller MB, Gilje S, Kaner RB, Wallace GG (2008) Processable aqueous dispersions of graphene nanosheets. Nat Nanotechnol 3:101â105Li X, Cai W, An J et al (2009) Large-area synthesis of high-quality and uniform graphene films on copper foils. Science 324:1312â1314Maitra U, Matte HSRR, Kumar P, Rao CNR (2012) Strategies for the synthesis of graphene, graphene nanoribbons, nanoscrolls and related materials. Chimia 66:941â948Mei XG, Ouyang JY (2011) Ultrasonication-assisted ultrafast reduction of graphene oxide by zinc powder at room temperature. Carbon 49:5389â5397Mkhoyan K, Contryman A, Silcox J, Stewart D, Eda G, Mattevi C, Miller S, Chhowalla M (2009) Atomic and electronic structure of graphene-oxide. Nano Lett 9:1058â1063Nair RR, Blake P, Grigorenko AN et al (2008) Fine structure constant defines visual transparency of graphene. Science 320:1308Park S, Lee KS, Bozoklu G et al (2008) Graphene oxide papers modified by divalent ions enhancing mechanical properties via chemical cross-linking. ACS Nano 2:572â578Park S, An J, Jung I et al (2009) Colloidal suspensions of highly reduced graphene oxide in a wide variety of organic solvents. Nano Lett 9:1593â1597Park HJ, Meyer J, Roth S, SkĂĄkalovĂĄ V (2010) Growth and properties of few-layer graphene prepared by chemical vapor deposition. Carbon 48:1088â1094Park S, An J, Potts JR, Velamakanni A, Murali S, Ruoff RS (2011) Hydrazine-reduction of graphite- and graphene oxide. Carbon 49:3019â3023Patil AJ, Vickery JL, Scott TB, Mann S (2009) Aqueous stabilization and self-assembly of graphene sheets into layered bio-nanocomposites using DNA. Adv Mater 21:3159â3164Stankovich S, Piner RD, Chen X, Wu N, Nguyen SBT, Ruoff RS (2006) Stable aqueous dispersions of graphitic nanoplatelets via the reduction of exfoliated graphite oxide in the presence of poly(sodium 4-styrenesulfonate). J Mater Chem 16:155â158Subrahmanyam KS, Panchakarla LS, Govindaraj A, Rao CNR (2009) Simple method of preparing graphene flakes by an arc-discharge method. J Phys Chem C 113:4257â4259SzabĂł T, Tombacz E, Illes E, DĂ©kĂĄny I (2006) Enhanced acidity and pH-dependent surface charge characterization of successively oxidized graphite oxides. Carbon 44:537â545Wu JS, Pisula W, Mullen K (2007) Graphenes as potential material for electronics. Chem Rev 107:718â747Wu H, Zhao WF, Hu HW, Chen GH (2011) One-step in situ ball milling synthesis of polymer-functionalized graphene nanocomposites. J Mater Chem 21:8626â8632Xu Y, Bai H, Lu G, Li C, Shi G (2008) Flexible graphene films via the filtration of water-soluble noncovalent functionalized graphene sheets. J Am Chem Soc 130:5856â5857Yin Z, Wu S, Zhou X et al (2010) Electrochemical deposition of ZnO nanorods on transparent reduced graphene oxide electrodes for hybrid solar cells. Small 6:307â312Zhang L, Liang J, Huang Y, Ma Y, Wang Y, Chen YS (2009) Size-controlled synthesis of graphene oxide sheets on a large scale using chemical exfoliation. Carbon 47:3365â3380Zhang J, Yang H, Shen G, Cheng P, Zhang J, Guo S (2010) Reduction of graphene oxide via l-ascorbic acid. Chem Comm 46:1112â1114Zhou Y, Bao Q, Tang LAL, Zhong Y, Loh KP (2009) Hydrothermal dehydration for the âgreenâ reduction of exfoliated graphene oxide to graphene and demonstration of tunable optical limiting properties. Chem Mater 21:2950â295
Recommended from our members
Application of Data Mining to forecast Air Traffic: A 3-Stage Model using Discrete Choice Modeling
The main goal of this study centers on developing an aggregate air itinerary share model estimated at the city-pair level within the US air transportation system. This route demand assignment model is part of a new modeling approach that has as its ultimate output the prediction of detailed traffic information for the US air transportation system. In this approach, city-pair demand generation, route demand assignment and air traffic levels estimations are completed in 3 different stages within a single framework. Aiming to fully develop the overall model, in this paper we focus on estimating the 2nd stage, the air itinerary choice model. In order to achieve this, the first approach taken applies a multinomial logit model and uses a combination of stated preferences (SP) and revealed preferences (RP) data to estimate the model. By using a mixed dataset, we attempt to improve the RP model results, which often perform poorly due to high demand inelasticity. Preliminary results show the potential of this approach, although further analysis is required to understand the results obtained. For the final paper, different approaches and further interactions among the model attributes will be applied to improve the modelâs performance
Recommended from our members
Air itinerary shares estimation using multinomial logit models
The main goal of this study is the development of an aggregate air itinerary market share model. In order to achieve this, multinomial logit models are applied to distribute the city-pair passenger demand across the available itineraries. The models are developed at an aggregate level using open-source booking data for a large group of city-pairs within the US air transport system. Although there is a growing trend in the use of discrete choice models in the aviation industry, existing air itinerary share models are mostly focused on supporting carrier decision-making. Consequently, those studies define itineraries at a more disaggregate level using variables describing airlines and time preferences. In this study, we define itineraries at a more aggregate level, i.e. as a combination of flight segments between an origin and destination, without further insight into service preferences. Although results show some potential for this approach, there are challenges associated with prediction performance and computational intensity
WITHIN SUBJECT VARIABILITY ANALYSIS REVEALS A TRANSITION POINT FOR THE LONGSWING ACROSS AGE GROUPS
This research aimed to observe changes in the within subject variability of the longswing performance and coordination across age groups in gymnasts divided by their competition level, from younger (group 1) to experts (group 5). Data were collected by two video cameras. Performance and coordinative within subject variability were calculated by the standard deviation (inter-trial variability) and the deviation phase (intra-trial variability). Results only showed significant group differences for within subject variability (inter- and intra-trial) in the SD P3H-P3S. In addition, group 4 (14.78±0.57 yrs) showed both large inter-trial variability in the upswing shoulder flexion (P3) and large intra-trial variability during hip and shoulder extension (P2) and P3. Such large variability in group 4 suggests a transition point towards the expertsŽ performance and coordination (19.96±3.37 yrs)
PRACTICE AND TALENT EFFECTS IN SWING HIGH BAR INTER-JOINT COORDINATION OF NOVICE ADULTS
This research describes changes in movement coordination after a two-month practice period of the swing on high bar in a novice cohort, which was divided by a-priory talent level into two groups: spontaneous-talented, ST, and non-spontaneous-talented, NST. Their performance was also compared with experienced gymnasts. Data were collected during pre- and post-practice sessions by two video cameras. Coordination between hip and shoulder joints was assessed. Results showed a similar practice effect in the swing enlargements in both novice groups. Interestingly, the ST groupâs inter-joint coordination variables on the downswing improved more than those of the NST group due to practice. Therefore, the two novice groups improved performance, but they showed diferent local coordination. Initial talent helped to improve both performance and coordination in the down-swing
- âŠ