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Glass Plate (glass + plate)
Selected AbstractsTechniques to measure the dry aeolian deposition of dust in arid and semi-arid landscapes: a comparative study in West NigerEARTH SURFACE PROCESSES AND LANDFORMS, Issue 2 2008Dirk Goossens Abstract Seven techniques designed to measure the dry aeolian deposition of dust on a desert surface were tested during field experiments in Niger, central-west Africa. Deposition fluxes were measured during eight periods of 3,4 days each. Experimental techniques tested were the MDCO (marble dust collector) method, the Frisbee method, the glass plate method (optical analysis of dust deposited on glass surfaces using particle imaging software), the soil surface method (deposition on a simulated desert floor) and the CAPYR (capteur pyramidal) method. Theoretical techniques tested were the inferential method and the combination method (gradient method extended with a deposition term for coarse dust particles). The results obtained by the MDCO, Frisbee, inferential and combination methods could be directly compared by converting the data to identical standard conditions (deposition on a water surface producing no resuspension). The results obtained by the other methods (glass plate, soil surface, CAPYR) were compared relatively. The study shows that the crude (unconverted) deposition fluxes of the five experimental techniques were similar, while the crude deposition fluxes calculated by the two theoretical techniques were substantially higher, of the order of four to five times as high as for the experimental techniques. Recalculation of the data to identical environmental conditions (the standard water surface) resulted in nearly identical deposition fluxes for the MDCO, Frisbee, inferential and combination techniques, although the latter two still had slightly higher values (but the differences remained small). The measurements illustrate the need to include a grain shape factor in theoretical dust deposition models. Without such a factor, theoretical models overestimate the deposition. The paper also discusses the advantages and disadvantages of the techniques tested. Copyright © 2007 John Wiley & Sons, Ltd. [source] Electrochemical Cholesterol Sensor Based on Tin Oxide-Chitosan Nanobiocomposite FilmELECTROANALYSIS, Issue 8 2009Anees Abstract A chitosan (CS)-tin oxide (SnO2) nanobiocomposite film has been deposited onto an indium-tin-oxide glass plate to immobilize cholesterol oxidase (ChOx) for cholesterol detection. The value of the Michaelis,Menten constant (Km) obtained as 3.8,mM for ChOx/CS-SnO2/ITO is lower (8,mM) than that of a ChOx/CS/ITO bioelectrode revealing enhancement in affinity and/or activity of ChOx towards cholesterol and also revealing strong binding of ChOx onto CS-SnO2/ITO electrode. This ChOx/CS-SnO2/ITO cholesterol sensor retains 95% of enzyme activity after 4,6 weeks at 4,°C with response time of 5,s, sensitivity of 34.7,,A/mg dL,1 cm2 and detection limit of 5,mg/dL. [source] Role of uppermost superficial surface layer of articular cartilage in the lubrication mechanism of jointsJOURNAL OF ANATOMY, Issue 3 2001P. KUMAR The uppermost superficial surface layer of articular cartilage, the ,lamina splendens' which provides a very low friction lubrication surface in articular joints, was investigated using atomic force microscopy (AFM). Complementary specimens were also observed under SEM at ,10 °C without dehydration or sputter ion coating. Fresh adult pig osteochondral specimens were prepared from the patellas of pig knee joints and digested with the enzymes, hyaluronidase, chondroitinase ABC and alkaline protease. Friction coefficients between a pyrex glass plate and the osteochondral specimens digested by enzymes as well as natural (undigested) specimens were measured, using a thrust collar apparatus. Normal saline, hyaluronic acid (HA) and a mixture of albumin, globulin, HA (AGH) were used as lubrication media. The surface irregularities usually observed in SEM studies were not apparent under AFM. The articular cartilage surface was resistant to hyaluronidase and also to chondroitinase ABC, but a fibrous structure was exhibited in alkaline protease enzymes-digested specimens. AFM analysis revealed that the thickness of the uppermost superficial surface layer of articular cartilage was between 800 nm and 2 ,m in adult pig articular cartilage. The coefficient of friction (c.f.) was significantly higher in chondroitinase ABC and alkaline protease enzymes digested specimens. Generally, in normal saline lubrication medium, c.f. was higher in comparison to HA and AGH lubrication media. The role of the uppermost, superficial surface layer of articular cartilage in the lubrication mechanism of joints is discussed. [source] HTPB-based polyurethaneurea membranes for recovery of aroma compounds from aqueous solution by pervaporationJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2007Yunxiang Bai Abstract Hydroxyterminated polybutadiene (HTPB)-based polyurethaneurea (PU), HTPB-PU, was synthesized by two-step polymerization and was firstly used as membrane materials to recover aroma, ethyl acetate (EA), from aqueous solution by pervaporation (PV). The effects of the number,average molecular weight (Mn) of HTPB, EA in feed, operating temperature, and membrane thickness on the PV performance of HTPB-PU membranes were investigated. The membranes demonstrated high EA permselectivity as well as high EA flux. The DSC result showed two transition temperatures in the HTPB-PU membrane and contact angle measurements revealed the difference of hydrophobicity of the membrane at both sides, which were induced by glass plate and air, respectively, due to movement of the soft hydrophobic polybutadiene (PB) segments in HTPB-PU chains. Furthermore, the PV performance of the HTPB-PU membrane with the hydrophobic surface facing the feed was much better than that with the hydrophilic surface. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 552,559, 2007 [source] Nucleic acid sensor for insecticide detectionJOURNAL OF MOLECULAR RECOGNITION, Issue 4 2008Pratima R. Solanki Abstract Nucleic acid sensor based on polyaniline (PANI) has been fabricated by covalently immobilizing double stranded calf thymus (dsCT) DNA onto perchlorate (ClO,4)-doped PANI film deposited onto indium-tin-oxide (ITO) glass plate using 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC)/N -hydroxysuccinimide (NHS) chemistry. These dsCT-DNA-PANI-ClO4/ITO and PANI-ClO4/ITO electrodes have been characterized using square wave voltammetry, electrochemical impedance, scanning electron microscopy (SEM) and Fourier-transform-infrared (FTIR) measurements. This disposable dsCT-DNA-PANI-ClO4/ITO bioelectrode, stable for about 4 months, can be used to detect cypermethrin (0.005,ppm) and trichlorfon (0.01,ppm) in 30 and 60,s, respectively. Copyright © 2008 John Wiley & Sons, Ltd. [source] Investigation of a New Approach to Measuring Contact Angles for Hydrophilic Impression MaterialsJOURNAL OF PROSTHODONTICS, Issue 2 2007Gerard Kugel DMD Purpose: The purpose of this investigation was to examine the initial water contact angles of seven unset impression materials using commercially available equipment, in an effort to determine whether polyether impression materials (Impregum) have lower contact angles and are, therefore, more hydrophilic than VPS impression materials. Materials and Methods: The hydrophilic properties of unset polyether and VPS impression materials were analyzed with respect to their water contact angle measurements using the commercially available Drop Shape Analysis System DSA 10. Twenty-five data points per second were collected via video analysis. There was no delay from start of measurement and data collection. Data was collected for approximately 12 s. Droplet size was determined on the thickness of canula. If the droplets became too small in volume, the water that evaporated during the measurement was large in comparison to the volume of the droplet. Therefore, 5 ,l was chosen as the lowest volume. Five trials were conducted per series for each featured material. Contact angles were calculated using the circle fitting method. Three tests using this technique were designed to control the variables of contact angle measurement with regard to time, the varying amount of fluid in contact with impression material during clinical use, and material thickness. Sample thickness of impression material was controlled by stripping the paste flat on a glass plate using a marking template to ensure a constant film thickness. Tests were conducted in a climatized room at 24°C ± 1°C. Deionized water was used as the fluid. The device was calibrated according to manufacturer's instruction for Young,Laplace fitting prior to the measurements. Results were analyzed using One-Way ANOVA, Tukey test, and t -test, as appropriate. Results: Comparing the fast setting impression materials by One-Way ANOVA and Tukey tests (p < .05) revealed the initial contact angles to range from 66.2 ± 1.5° to 127.5 ± 4.4°, of which the polyether material was the lowest after 45 s (66.2 ± 1.5°), 120 s (70.3 ± 2.8°), and 24 h (80.3 ± 1.0°) after start of the mix. The selected times represent the different stages of unset material, ranging from 45 s as the earliest practical data collection time to 24 h, at which a stone model would be poured. The polyether materials tested exhibited lower contact angles and, thus, significantly higher initial hydrophilicity than all measured VPS materials. Additionally, Impregum impression materials are more hydrophilic in the unset stage than in the set stage. VPS may show a stepwise development of hydrophilicity in the set stage that was not observed in the unset stage. Conclusions: The polyether impression materials tested were significantly more hydrophilic before, during, and after setting than that of VPS impression materials. Regardless of the amount of water in contact with the impression material, the polyether impression materials showed a significantly higher hydrophilicity in the unset stage than the VPS materials. The initial contact angle was not dependent on the thickness of the material. All parameters, including variation of time, volume of water droplet, and thickness of material, resulted in different absolute contact angles, but did not lead to a dramatic change in the ranking of the materials with regard to their hydrophilic behavior. [source] Application of ion beam techniques for preparation of metal ion-implanted TiO2 thin film photocatalyst available under visible light irradiation: metal ion-implantation and ionized cluster beam methodJOURNAL OF SYNCHROTRON RADIATION, Issue 2 2001Hiromi Yamashita Transparent TiO2 thin film photocatalysts have been prepared on silica glass plate by an ionized cluster beam (ICB) method. In order to improve the electronic properties of these photocatalysts, transition metal ions V+, Cr+, Mn+, Fe+) were implanted into the TiO2 thin films at high energy acceleration using an advanced metal ion-implantation technique. The combination of these ion beam techniques can allow us to prepare the TiO2 thin film photocatalysts which can work effectively under visible light (, > 450 nm) and/or solar light irradiation. The investigation using XAFS and ab initio molecular calculation suggests that the substitution of octahedrally coordinated Ti ions in TiO2 lattice with implanted metal ions is important to modify TiO2 to be able to adsorb visible light and operate under visible light irradiation. [source] Structural Changes in Silica Glass by Continuous-Wave Laser Backside IrradiationJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 6 2010Hirofumi Hidai We report on a permanent change in the physical properties inside silica glass by rapid heating and quenching using a continuous-wave laser beam. The absorption of the glass was enhanced by laser heating, and the heated spot moved as a result of thermal radiation and conduction. To trigger heating, an absorbent material was placed on the backside of a glass plate and irradiated through the glass. Laser illumination with a power of 11 W focused on the absorbent material induced a cylindrical modified zone along the laser beam with a length of up to 5.5 mm that was modified at a rate of ,130 mm/s. The characteristics of the modified silica glass were studied. The modified area consists of two layers, and the diameters of the inner and outer zones are ,40 and ,55 ,m, respectively. The inner zone was modified by laser heating. The fictive temperature is estimated to be ,1900 K. The etch rate and hardness of the modified glass increased owing to the increment of the fictive temperature. The outer zone was modified by tensile stress due to the densification of the inner zone. In the outer zone, the etch rate is increased and hardness is decreased. [source] Microtransfer Molding of Gelcasting Suspensions to Fabricate Barrier Ribs for Plasma Display PanelJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 11 2003Jooho Moon We have developed a new fabrication technique for the barrier ribs of a plasma display panel (PDP). The rib structure was formed on a glass plate by microtransfer molding a gelcasting suspension with a flexible soft mold. A well,dispersed gelcasting suspension of the glass frit was placed on the photolithographically patterned mold, followed by gelation and drying while pressed with a top glass plate. The rib structure replicated by micromolding was significantly influenced by the gelation kinetics, the green strength of the gelled body, and the mold release process. It was demonstrated that the box,type array of 1176 wells in the patterned area of 6.5 cm × 6.5 cm could be produced using the current method. [source] Synthesis and properties of BCDA-based polyimide,clay nanocompositesPOLYMER INTERNATIONAL, Issue 6 2007P Santhana Gopala Krishnan Abstract Bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride (BCDA)-based polyimide,clay nanocomposites were prepared from their precursor, namely polyamic acid, by a solution-casting method. The organoclay was prepared by treating sodium montmorillonite (Kunipia F) clay with dodecyltrimethylammonium bromide at 80 °C. Polyamic acid solutions containing various weight percentages of organoclay were prepared from 4,4,-(4,4,-isopropylidenediphenyl-1,1,-diyldioxy)-dianiline and BCDA in N -methyl-2-pyrrolidone containing dispersed particles of organoclay at 20 °C. These solutions were cast on a glass plate using a Doctor's blade and then heated subsequently to obtain nanocomposite films. The nanocomposites were characterized using Fourier transform infrared spectroscopy, differential scanning calorimetry, thermal mechanical analysis, dynamic mechanical analysis, polarizing microscopy, scanning electron microscopy, transmission electron microscopy, wide-angle X-ray diffraction (WAXD) and thermogravimetric analysis. The glass transition temperature of the nanocomposites was found to be higher than that of pristine polymer. The coefficient of thermal expansion of the nanocomposites decreased with increasing organoclay content. WAXD studies indicated that the extent of silicate layer separation in the nanocomposite films depended upon the organoclay content. Tensile strength and modulus of the nanocomposite containing 1% organoclay were significantly higher when compared to pristine polymer and other nanocomposites. The thermal stability of the nanocomposites was found to be higher than that of pristine polymer in air and nitrogen atmosphere. Copyright © 2007 Society of Chemical Industry [source] Silica-supported biomimetic membranesTHE CHEMICAL RECORD, Issue 6 2004Katsuhiko Ariga Abstract The hybridization of lipid membranes with inorganic silica-based framework results in mechanically stable biomembrane mimics. This account describes three types of silica-based biomimetic membranes. As the first example, a Langmuir monolayer of dialkylalkoxysilane was polymerized and immobilized onto a porous glass plate. Permeability through the monolayer-immobilized glass was regulated by phase transition of the immobilized monolayer. In the second example, spherical vesicles covalently attached to a silica cover layer (Cerasome) were prepared. The Cerasome was stable enough to be assembled into layer-by-layer films without destruction of its vesicular structure. This material could be an example of the multicellular assembly. Mesoporous silica films densely filling peptide assemblies (Proteosilica) are introduced as the third example. The Proteosilica was synthesized as a transparent film through template sol-gel reaction using amphiphilic peptides. © 2004 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 3: 297,307; 2004: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.10071 [source] Magnetic field exposure stiffens regenerating plant protoplast cell wallsBIOELECTROMAGNETICS, Issue 2 2006Toshihiko Haneda Abstract Single suspension-cultured plant cells (Catharanthus roseus) and their protoplasts were anchored to a glass plate and exposed to a magnetic field of 302,±,8 mT for several hours. Compression forces required to produce constant cell deformation were measured parallel to the magnetic field by means of a cantilever-type force sensor. Exposure of intact cells to the magnetic field did not result in any changes within experimental error, while exposure of regenerating protoplasts significantly increased the measured forces and stiffened regenerating protoplasts. The diameters of intact cells or regenerating protoplasts were not changed after exposure to the magnetic field. Measured forces for regenerating protoplasts with and without exposure to the magnetic field increased linearly with incubation time, with these forces being divided into components based on the elasticity of synthesized cell walls and cytoplasm. Cell wall synthesis was also measured using a cell wall-specific fluorescent dye, and no changes were noted after exposure to the magnetic field. Analysis suggested that exposure to the magnetic field roughly tripled the Young's modulus of the newly synthesized cell wall without any lag. Bioelectromagnetics 27:98,104, 2006. © 2005 Wiley-Liss, Inc. [source] Soft-Contact Optical Lithography Using Transparent Elastomeric Stamps and Application to Nanopatterned Organic Light-Emitting DevicesADVANCED FUNCTIONAL MATERIALS, Issue 9 2005T.-W. Lee Abstract Conventional photolithography uses rigid photomasks of fused quartz and high-purity silica glass plates covered with patterned microstructures of an opaque material. We introduce new, transparent, elastomeric molds (or stamps) of poly(dimethylsiloxane) (PDMS) that can be employed as photomasks to produce the same resist pattern as the pattern of the recessed (or non-contact) regions of the stamps, in contrast to other reports in the literature[1] of using PDMS masks to generate edge patterns. The exposure dose of the non-contact regions with the photoresist through the PDMS is lower than that of the contact regions. Therefore, we employ a difference in the effective exposure dose between the contact and the non-contact regions through the PDMS stamp to generate the same pattern as the PDMS photomask. The photomasking capability of the PDMS stamps, which is similar to rigid photomasks in conventional photolithography, widens the application boundaries of soft-contact optical lithography and makes the photolithography process and equipment very simple. This soft-contact optical lithography process can be widely used to perform photolithography on flexible substrates, avoiding metal or resist cracks, as it uses soft, conformable, intimate contact with the photoresist without any external pressure. To this end, we demonstrate soft-contact optical lithography on a gold-coated PDMS substrate and utilized the patterned Au/PDMS substrate with feature sizes into the nanometer regime as a top electrode in organic light-emitting diodes that are formed by soft-contact lamination. [source] Polymerization stress, flow and dentine bond strength of two resin-based root canal sealersINTERNATIONAL ENDODONTIC JOURNAL, Issue 10 2009S. F. C. Souza Abstract Aim, To compare two resin-based root canal sealers (AH Plus and dual cure Epiphany) in terms of flow, polymerization stress and bond strength to dentine. Methodology, Flow was evaluated by measuring the diameter of uncured discs of sealer (0.5 mL) after 7 min compression (20N) between two glass plates (n = 5). Polymerization stress was monitored for 60 min in 1-mm thick discs bonded to two glass rods (Ø = 5 mm) attached to a universal testing machine (n = 3). Bond strength was analyzed through micropush-out test (n = 10) and failure mode was examined with scanning electron microscope (100× and 2500×). Data were statistically analyzed using the Student's t -test (, = 0.05). Results, Polymerization stress was 0.32 ± 0.07 MPa for Epiphany self-cure, 0.65 ± 0.08 MPa for Epiphany light-cure and zero for AH Plus (P < 0.05). Flow data and bond strength values were 30.9 ± 1.1, 28.6 ± 0.7 mm and 6.3 ± 5.3, 17.8 ± 7.5 MPa for Epiphany and AH Plus, respectively (P < 0.001). Failure mode was predominantly cohesive in the sealer for both materials. Conclusions, Epiphany had higher flow and polymerization stress and lower bond strength values to dentine than AH Plus. In view of these findings it can be implied that AH Plus would provide a better seal. [source] OXYGEN-INHIBITED LAYER IN ADHESION DENTISTRYJOURNAL OF ESTHETIC AND RESTORATIVE DENTISTRY, Issue 5 2004Byoung I. Suh MS ABSTRACT Purpose:: Characteristics of the oxygen-inhibited layer, including bond strength, photoinitiator decomposition, and post-curing degree of conversion, were investigated. Materials and Methods: To investigate shear bond strength, BisCover (Bisco, Inc., Schaumburg, IL, USA) and D/E Resin (Bisco, Inc.) were placed on disks of Renew composite (Bisco, Inc.) and cured both with and without an oxygen-inhibited layer. Light-Bond composite (Reliance Orthodontic, Itasca, IL, USA) was placed in a gelatin capsule and light cured over the cured resin. After soaking in water for 2 hours at 37°C, specimens were sheared to failure using a universal testing machine (Model 4466, Instron Inc., Canton, MA, USA). To investigate microtensile bond strength, composite substrates prepared using Renew A2 composite were light cured either in air or under nitrogen. Light-Core (Bisco, Inc.) was placed on each substrate and light cured. The resulting specimens were sectioned into composite beams and stressed to failure using a microtensile tester (built by Bisco, Inc.). To determine camphorquinone (CQ) decomposition, an experimental CQ resin was placed between two glass plates and irradiated for different time intervals. The absorption spectrum was obtained using a Cary 50 Bio UV-Visible Spectrometer (Varian, Mulgrave, Australia). To explore the degree of conversion, polyester film strips (Mylar, DuPont, Wilmington, DE, USA) coated with the CQ resin were pre-cured in air for different time periods, and then post-cured at low intensity for 5 minutes under nitrogen. A Spectrum 1000FTIR Spectrometer (Perkin Elmer, Norwalk, CT, USA) was used to measure the degree of conversion. Results: Bond strength tests resulted in no significant difference between samples with or without an oxygen-inhibited layer. The oxygen-inhibited layer contained reduced amounts of photoinitiator. The degree of conversion of post-cured oxygen-inhibited layers was lower than that for the control. Conclusion: An oxygen-inhibited layer is not necessary for bonding with composite resin. [source] Crack Tip Morphology of Slowly Growing Cracks in GlassJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 2 2000Stéphane Hénaux We present atomic force microscopy (AFM) observations of crack tips in glass during subcritical propagation. These have been obtained by means of an AFM sample holder which has been specially designed to propagate indentation cracks in glass plates. Crack tips in soda,lime,silica glass are always preceded by a few nanometers deep deformation. In vitreous silica, no other surface deformation than the crack itself could be detected. For both materials, the crack opening is found to largely exceed the elastic solution. [source] Titanium dioxide thin films deposited by the sol-gel technique starting from titanium oxy-acetyl acetonate: gas sensing and photocatalyst applicationsPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 9 2010A. Maldonado Abstract Titanium dioxide (TiO2) thin films were deposited onto sodocalcic glass plates by the sol-gel technique, starting from a non-alkoxide route, namely, titanium oxy-acetyl acetonate as Ti precursor. Film thickness effect on both the gas sensing and photocatalytic degradation performance was studied. The as-deposited films were annealed in air at 400 °C. All the X-ray spectra of the films show a very broad-peak centered in a 2, angle around 30°. In the case of the thinnest films the surface morphology is uniform and very smooth, whereas for the thickest films the corresponding surface is covered by grains with a rod-like shape with a length on the order of 140 nm. The films were tested both for two straightforward applications: ultraviolet assisted-degradation of methylene blue dissolved in water, at different times, as well as gas sensor in a controlled propane (C3H8) atmosphere. As the film thickness increases, the degradation of methylene blue (MB) also increases. The thickest TiO2 thin films after being exposed by 5 hours to the catalytic degradation, promoted by ultraviolet illumination, showed a final MB solution degradation in the order of 48%. This reult can be associated with the increase in the effective exposed area of the TiO2 thin films. On the other hand, the exposition of the films to a controlled propane atmosphere produced a significant change in the surface electrical resistance of the films at operating temperatures of 200 °C and above. In fact, in the case of the thickest TiO2 films, a dramatic electrical resistance change of non-exposed and propane exposed , 560 to 0.7 M, ,, was registered. The results show that TiO2 films deposited by an economical deposition technique, as is the case of the sol-gel technique, could have an important potential in industrial applications. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Organic,inorganic hybrid materials derived from epoxy resin and polysiloxanes: Synthesis and characterizationPOLYMER ENGINEERING & SCIENCE, Issue 1 2008C.F. Canto In this study, hybrid materials based on epoxy resin were prepared as transparent self-supported films by a sol,gel process. 4,4,-Diaminodiphenylmethane or oligomeric epoxy resin were used as precursors, which were conveniently functionalized with trialkoxysilanes as end-groups. The effect of the introduction of poly (dimethylsiloxane) was also investigated. The hybrid films showed good thermal stability, a nondefined glass transition temperature, and a dense morphology without phase segregation. The tendency to a flat surface could be observed by atomic force microscopy. The hybrid films also showed good performance as coatings for glass plates, with an improved hydrophobic character in comparison to neat epoxy resin. POLYM. ENG. SCI., 48:141,148, 2008. © 2007 Society of Plastics Engineers [source] Role of polymer chain end groups in plasma modification for surface metallization of polymeric materialsPOLYMER INTERNATIONAL, Issue 6 2009Norihiro Inagaki Abstract How to improve adhesion between poly(oxybenzoate- co -oxynaphthoate) (Vecstar OC and FA films) and copper metal by Ar, O2, N2 and NH3 plasma modification was investigated. The mechanism of adhesion improvement is discussed from the viewpoint of chemical and physical interactions at the interface between the Vecstar film and copper metal layer. The adhesion between Vecstar OC film and copper metal was improved by chemical rather than physical interactions. Polymer chain end groups that occur at Vecstar OC film surfaces contribute effectively to adhesion. This improvement in adhesion is due to interactions between copper metal and OC groups formed by plasma modification. Aggregation of the OC groups to the copper metal/Vecstar OC film interface is a key factor for good adhesion. From this aspect, heat treatment of plasma-modified Vecstar OC films on glass plates is effective in the aggregation, and the peel strength for the copper metal/Vecstar OC film system reached 1.21 N (5 mm),1. Copyright © 2009 Society of Chemical Industry [source] Regulation of plasminogen activator inhibitor 1 expression in human osteoarthritic chondrocytes by fluid shear stress: Role of protein kinase C,ARTHRITIS & RHEUMATISM, Issue 8 2009Chih-Chang Yeh Objective To test a fluid flow system for the investigation of the influence of shear stress on expression of plasminogen activator inhibitor 1 (PAI-1) in human osteoarthritic (OA) articular chondrocytes (from lesional and nonlesional sites) and human SW-1353 chondrocytes. Methods Human SW-1353 chondrocytes and OA and normal human articular chondrocytes were cultured on type II collagen,coated glass plates under static conditions or placed in a flow chamber to form a closed fluid-circulation system for exposure to different levels of shear stress (2,20 dyn/cm2). Real-time polymerase chain reaction was used to analyze PAI-1 gene expression, and protein kinase C (PKC) inhibitors and small interfering RNA were used to investigate the mechanism of shear stress,induced signal transduction in SW-1353 and OA (lesional and nonlesional) articular chondrocytes. Results There was a significant reduction in PAI-1 expression in OA chondrocytes obtained from lesional sites compared with those obtained from nonlesional sites. In SW-1353 chondrocytes subjected to 2 hours of shear flow, moderate shear stresses (5 and 10 dyn/cm2) generated significant PAI-1 expression, which was regulated through PKC, phosphorylation and Sp-1 activation. These levels of shear stress also increased PAI-1 expression in articular chondrocytes from nonlesional sites and from normal healthy cartilage through the activation of PKC, and Sp-1 signal transduction, but no effect of these levels of fluid shear stress was observed on OA chondrocytes from lesional sites. Conclusion OA chondrocytes from lesional sites and those from nonlesional sites of human cartilage have differential responses to shear stress with regard to PAI-1 gene expression, and therefore diverse functional consequences can be observed. [source] A robotic system for crystallizing membrane and soluble proteins in lipidic mesophasesACTA CRYSTALLOGRAPHICA SECTION D, Issue 10 2004Vadim Cherezov A high-throughput robotic system has been developed for crystallizing membrane proteins using lipidic mesophases. It incorporates commercially available components and is relatively inexpensive. The crystallization robot uses standard automated liquid-handlers and a specially built device for accurately and reproducibly delivering nanolitre volumes of highly viscous protein/lipid mesophases. Under standard conditions, the robot uses just 20,nl protein solution, 30,nl lipid and 1,µl precipitant solution. 96 wells can be set up using the robot in 13,min. Trials are performed in specially designed 96-well glass plates. The slim (<2,mm high) plates have exquisite optical properties and are well suited for the detection of microcrystals and for birefringence-free imaging between crossed polarizers. Quantitative evaluation of the crystallization progress is performed using an automated imaging system. The optics, in combination with the slim crystallization plates, enables in-focus imaging of the entire well volume in a single shot such that a 96-well plate can be imaged in just 4.5,min. The performance characteristics of the robotic system and the versatility of the crystallization robot in performing vapor-diffusion, microbatch and bicelle crystallizations of membrane and soluble proteins are described. [source] Study of Langmuir,Blodgett phospholipidic films deposited on surface enhanced Raman scattering active gold nanoparticle monolayersBIOPOLYMERS, Issue 4-5 2002S. Bernard Abstract Surface enhanced Raman scattering (SERS) was used to study phospholipid monolayers transferred by the Langmuir,Blodgett (LB) technique to SERS active substrates. These substrates, which were constituted of gold colloidal nanoparticles bound to polysilane films grafted onto glass plates, showed a uniform and homogeneous layer with strong interacting particles as revealed from UV,visible extinction spectra and atomic force microscopy images. Laser excitation at 632.8 nm within the red part of the localized surface plasmon resonance leads to intense and reproducible SERS spectra of trans -1,2-bis(4-pyridyl)ethylene (BPE). From SERS measurements at different pHs it was possible to determine the apparent pKa of BPE adsorbed on gold-coated silanized substrates in the absence and presence of one LB monomolecular layer of phospholipids. These SERS titrations allowed the estimation of the pH at the metal,LB film interface. © 2002 Wiley Periodicals, Inc. Biopolymers (Biospectroscopy) 67: 314,318, 2002 [source] | ||||||||||||||||||||||