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Microscope
Kinds of Microscope Terms modified by Microscope Selected AbstractsUSING INCIDENT LIGHT TO MAXIMIZE RESOLUTION OF STRUCTURE ON DIATOM VALVES WITH A LIGHT MICROSCOPEJOURNAL OF PHYCOLOGY, Issue 2001Article first published online: 24 SEP 200 Siver, P. A. Botany Department, Connecticut College, New London, CT 06320 Because of their abundance in a diverse array of aquatic habitats and chemical conditions, and the fact that their species-specific siliceous outer coverings remain for millennia in sediments, diatoms have become one of the most powerful organismal groups used in the reconstruction of historical environmental conditions. Although SEM is now needed to identify some species, the bulk of the identifications and data collection is still accomplished with a light microscope. In this paper I will demonstrate the use of interference reflection contrast (incident light) for the examination of diatoms that significantly improves the resolution of structural detail. Using incident light one can routinely distinguish between structures close to the theoretical limit of resolution for visible light, and about 70 nm closer together than resolvable with standard transmitted light optics. Examples of how the incident light technique can improve data collection with light microscopy will be given. Most research light microscopes could be easily and inexpensively outfitted to use this technique. [source] ROBUST TWO-DEGREE-OF-FREEDOM CONTROL OF AN ATOMIC FORCE MICROSCOPEASIAN JOURNAL OF CONTROL, Issue 2 2004G. Schitter ABSTRACT The performance of an atomic force microscope (AFM) is improved substantially by utilizing modern model-based control methods in comparison to a standard proportional-integral (PI) controlled AFM system. We present the design and implementation of a two-degree-of-freedom (2DOF)-controller to accomplish topography measurements at high scan-rates with reduced measurement error. An H, -controller operates the AFM system in a closed loop while a model-based feedforward controller tracks the scanner to the last recorded scan-line. Experimental results compare the actual performance of the standard PI-controlled AFM and the 2DOF controlled system. The new controller reduces the control error considerably and enables imaging at higher speeds and at weaker tip-sample interaction forces. [source] Characterization of reactive DC magnetron sputtered TiAlN thin filmsCRYSTAL RESEARCH AND TECHNOLOGY, Issue 10 2008B. Subramanian Abstract Thin films of about 1,m Titanium Aluminum Nitride (TiAlN) were deposited onto mild steel substrates by reactive direct current (DC) magnetron sputtering using a target consisting of equal segments of titanium and aluminum. X-ray diffraction (XRD) analysis showed that the TiAlN phase had preferred orientations along 111 and 200 with the face-centered cubic structure. Scanning Electron Microscope (SEM) and Atomic Force Microscope (AFM) analyses indicated that the films were uniform and compact. Photoluminescence (PL) spectra reveal that TiAlN thin films are of good optical quality. Laser Raman studies revealed the presence of characteristic peaks of TiAlN at 312.5, 675, and 1187.5 cm,1. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Structural analysis of human hair fibers under the ultra-high voltage electron microscopeINTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 2 2005K. Koike Three-dimensional structural analyses of human hair fibers and comparison of the different fibers were tried by using the Ultra-high Voltage Electron Microscope (UHVEM). The analysis condition, sample preparation, and a machine state were adjusted to the suitable condition for tilting observation of from ,70° to +70°, at 2° intervals. The tomography of hair fiber was successfully reconstructed from the different angle pictures with IMODE software in a computer. By using UHVEM, the various human hair fibers from Japanese and Caucasians were investigated and discussed about their structures. [source] Accessing Time,Varying Forces on the Vibrating Tip of the Dynamic Atomic Force Microscope to Map Material CompositionISRAEL JOURNAL OF CHEMISTRY, Issue 2 2008Ozgur Sahin In dynamic atomic force microscopes the primary physical quantities being measured are the amplitude/phase or amplitude/frequency of the vibrating force probe. Topographic images with spatial resolutions down to the atomic scale can be obtained by mapping these measurements across the sample surface under feedback control. During the imaging process the vibrating tip is observing tip,sample interaction potentials (force,distance relationships) at every point on the surface. The interaction potential is a superposition of short- and long,distance interactions of various origins determined by the material compositions of the tip, sample, and the medium of imaging. In principle, measurement of tip,sample interaction potential should allow determination and mapping of material composition of the sample. However, a single measurement of amplitude/phase or amplitude/frequency in dynamic atomic force microscopes is not enough to characterize a complicated tip,sample interaction potential. Recent developments in the understanding of dynamics of the vibrating force probe (cantilever), together with specially designed cantilevers that utilize torsional vibrations in addition to conventional vertical vibrations, enable the recovery of tip,sample interaction potentials at a timescale less than a millisecond. Here, with theory and experiments, we discuss how these cantilevers recover the information about the tip,sample interaction forces and give an example of compositional mapping on a polymeric material system. [source] Photopolymerization of clay/polyurethane nanocomposites induced by intercalated initiatorJOURNAL OF APPLIED POLYMER SCIENCE, Issue 4 2007Hailin Tan Abstract An intercalated initiator was synthesized and used for preparation of clay/polyurethane nanocomposites by UV irradiation. Organoclays containing initiator groups were prepared by cationic exchange process which acted as both suitable intercalant and photoinitiator. These modified clays were then dispersed in the mixture of urethane acrylate and hexanediol diacrylate in different loading, then situ photopolymerized. Intercalated and exfoliated nanocomposite structure were evidenced by both X-ray diffraction spectroscopy and Transmission Electron Microscope. Thermal properties and morphologies of the resultant nanocomposites were also investigated. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007 [source] Confocal Examination of Subsurface Cracking in Ceramic MaterialsJOURNAL OF PROSTHODONTICS, Issue 7 2009MMedSc, Maged K. Etman DDS Abstract Purpose: The original ceramic surface finish and its microstructure may have an effect on crack propagation. The purpose of this study was to investigate the relation between crack propagation and ceramic microstructure following cyclic fatigue loading, and to qualitatively evaluate and quantitatively measure the surface and subsurface crack depths of three types of ceramic restorations with different microstructures using a Confocal Laser Scanning Microscope (CLSM) and Scanning Electron Microscope (SEM). Materials and Methods: Twenty (8 × 4 × 2 mm3) blocks of AllCeram (AC), experimental ceramic (EC, IPS e.max Press), and Sensation SL (SSL) were prepared, ten glazed and ten polished of each material. Sixty antagonist enamel specimens were made from the labial surfaces of permanent incisors. The ceramic abraders were attached to a wear machine, so that each enamel specimen presented at 45 degrees to the vertical movement of the abraders, and immersed in artificial saliva. Wear was induced for 80K cycles at 60 cycles/min with a load of 40 N and 2-mm horizontal deflection. The specimens were examined for cracks at baseline, 5K, 10K, 20K, 40K, and 80K cycles. Results: Twenty- to 30-,m deep subsurface cracking appeared in SSL, with 8 to 10 ,m in AC, and 7 ,m close to the margin of the wear facets in glazed EC after 5K cycles. The EC showed no cracks with increasing wear cycles. Seventy-,m deep subsurface cracks were detected in SSL and 45 ,m in AC after 80K cycles. Statistically, there was significant difference among the three materials (p < 0.05). Bonferroni multiple comparison of means test confirmed the ANOVA test and showed that there was no statistical difference (p > 0.05) in crack depth within the same ceramic material with different surface finishes. Conclusions: The ceramic materials with different microstructures showed different patterns of subsurface cracking. [source] Under the Microscope: ArcobacterLETTERS IN APPLIED MICROBIOLOGY, Issue 1 2006W.J. Snelling Abstract This review describes characteristics of the genus Arcobacter. Unlike its close phenotypically related neighbour Campylobacter, Arcobacter is not currently a major public health concern, but is considered as an emerging human pathogen, and is of significance towards animal health. This review focuses on the public health significance, culturing and typing, reservoirs, and antimicrobial studies of Arcobacter. Collectively, increasing knowledge in these areas will help to develop measures, which can be used to control this emerging pathogen. [source] Microtribological behaviour of thin DLC films using different testing methodsLUBRICATION SCIENCE, Issue 2 2006R. Bandorf Abstract To enhance the lifetime and reliability of microcomponents, thin microtribological films are applied to microparts. With reduction of the component size, investigation methods for tribological testing must be adapted. This paper studies the microtribological behaviour of thin diamond-like carbon (DLC) films using different testing methods. To tie in with macroscopic results, to determine friction we used the well-known pin-on-disc test with spherical surfaces of 10,mm diameter under a typical load of 3,N. For investigations of the behaviour under single asperity contact, Atomic Force Microscope (AFM) methods with applied loads of a few hundred micronewtons were used. Investigations on thin DLC films showed that the friction coefficient under single asperity contact is strongly dependent on the applied load and the resulting contact area. Especially for thin films (up to a few hundred nanometres) the friction coefficient is influenced by the substrate material. With decreasing substrate Young's modulus the friction coefficient also decreases. On the other hand, an increase in the abrasive wear resistance was observed using soft substrate materials. In this paper we show that the friction coefficient was also reduced by a simple surface structure. For investigations we used photolithography to create concentric circles in different substrates. This resulted in a behaviour like riding on rails for the pin-on-disc test. Depending on the tribological pairing the friction coefficient was reduced to more than 50% of the original value. Copyright © 2006 John Wiley & Sons, Ltd. [source] Three-dimensional microscopy migrates to the web with "PowerUp Your Microscope"MICROSCOPY RESEARCH AND TECHNIQUE, Issue 2 2004Paola Bonetto Abstract "PowerUp Your Microscope" is a software package designed and realized for the optimization of 3D optical microscopy image quality using the Internet and inverse problems computational approaches. The package is mainly devoted to 3D microscopy users, being operative for wide-field, confocal, and multiphoton microscopy. It provides the microscopy community with an extremely easy and comparatively powerful access to advanced image restoration methods. The core of the computational section is the optical system modeling and inverse deconvolution implementation, which is strongly linked to Web-based software and technology. This project constitutes a real and effective migration to the Web, extending computational approaches to image restoration to the whole microscopy user community, regardless of their background. Microsc. Res. Tech. 64:196,203, 2004. © 2004 Wiley-Liss, Inc. [source] Henry George Under the Microscope: Comments on "Henry George's Political Critics"AMERICAN JOURNAL OF ECONOMICS AND SOCIOLOGY, Issue 5 2009Article first published online: 20 OCT 200, Richard Giles The annual supplement of the AJES for 2008 titled Henry George: Political Ideologue, Social Philosopher, and Economic Theorist had as its first and longest essay "Henry George's Political Critics" by Professor Michael Hudson. It offered a multitude of criticisms, most of which Prof. Hudson seemed to agree with. All purported to be criticisms of George as a political strategist, though some seem more to originate from Hudson's disagreement with theoretical positions George was bound to take. The purpose of this short paper is to show that Professor Hudson's long article fails to do what it seems intended to do. That is, it fails to show that trade unionists and especially socialists were "natural allies" of the Georgist movement, that it was George's fault that that they were not, and that George "allied" his movement irrevocably to "capital," rejecting its "natural allies." [source] Particle Imaging Using a Transmission Wide-Field Phase Confocal MicroscopePARTICLE & PARTICLE SYSTEMS CHARACTERIZATION, Issue 2 2003Eugene Astrakharchik-Farrimond Abstract A phase-sensitive wide field transmission microscope, combining the advantages of both interferometric and confocal techniques, has been developed and applied to analysis of particulates, both in dry powder form and in suspensions. The microscope has also been used in detecting defects in crystals. Confocal operation is achieved by superimposing speckle illumination of a reference beam in a Mach-Zehnder interferometer with a matched speckle pattern of the object beam. It is shown that the phase measurement enables particle size to be determined even when the particle is smaller than the focal spot size. The data acquisition time is below 1ms, making the system suitable for dynamic process measurement. The experimental results are in good agreement with modelled results giving rise to the possibility of simultaneous determination of both the size and refractive index of small particles. [source] Electrodeposition study of ODN:SWCNT hybrids on gold substratesPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 6 2008Roya R. Lahiji Abstract Sonication of short single-stranded DNA (oligodeoxyribonucleotide; ODN) with Single-Walled Carbon Nanotubes (SWCNTs) greatly facilitates the dispersion of SWCNTs from entangled ropes in an aqueous solution, creating ODN:SWCNT hybrids. Electrodeposition has been investigated to determine if well-dispersed ODN:SWCNT hybrids on a metal substrate can be created. Preliminary studies indicate that electrodeposition using an Au substrate held at +0.5 V produces ODN:SWCNT hybrids that are uniformly deposited across the Au substrate. This result can be compared to samples produced by drop casting and evaporation techniques which yield a thick tangled mat of ODN:SWCNT hybrids across the substrate. The resulting electrodeposited samples were characterized using Scanning Probe Microscope (SPM) and X-ray Photoemission Spectroscopy (XPS) techniques. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Investigation of HOLZ rings in EBSD patternsPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 6 2007E. Langer Abstract Higher-Order Laue Zone (HOLZ) rings and their appearance in Electron Backscattered Diffraction (EBSD) pattern from molybdenum were fundamentally investigated in the Scanning Electron Microscope. HOLZ rings of the type ,100,, ,110,, ,111,, ,113, and ,133, could be unambiguous detected in EBSD pattern of different pure Mo crystals. The [100] HOLZ ring was observed more in detail in dependence on the accelerating energy in the pattern center, and the lattice spacing was determined for all energies. A relatively good accuracy could be obtained for Mo as model sample for problematical high atomic number materials. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Etch-pits and threading dislocations in thick LEO GaN films on sapphire grown by MOCVDPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 10 2004Lu Min Abstract High quality Lateral Epitaxial Overgrowth (LEO) GaN films on (0001) sapphire substrates were grown by a commercial MOCVD system (Thomas Swan Corp.). We have studied the etch-pits and threading dislocations in GaN films by wet etching of pits, HCl vapor etching of pits and Scanning Electron Microscope (SEM). SEM images of GaN films etched in HCl vapor and molten KOH gave us notably different etching pits densities in the different region of LEO GaN films, which confirmed HCl vapor etching could show three kinds of Threading Dislocations (TDs), while molten KOH wet etching only could show pure screw TDs. In region above window TDs density is high (about 3 × 108/cm2) and edge TDs are in the majority, while it is almost free of TDs in region above mask, and only in middle region above mask there are some TDs (including all three kinds) and also edge TDs are in the majority. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Preparation and properties of polyurethane/montmorillonite nanocomposites cured under room temperaturePOLYMER COMPOSITES, Issue 5 2006Hangbin Jiang The polyurethane/C16C18 -MMT (the montmorillonite modified with cetyloctadecyldimethyl ammonium bromide) nanocomposites were synthesized by intercalative polymerization and cured under room temperature. The d -spacing and the dispersion of the C16C18 -MMT in the nanocomposites were measured by X-ray Diffraction (XRD) and Transmission Electron Microscope (TEM). The mechanical and thermal properties of the nanocomposites were measured by Universal Testing System, Electric Anti-fold Instrument, Thermogravimetric Analysis (TGA), and Differential Scanning Calorimetry (DSC). It was found out that introducing C16C18 -montmorillonite (MMT) in the polyurethane (PU) displayed good mechanical properties and thermal stability. Rheology behavior in liquid state showed that the addition of the C16C18 -MMT to PU resulted in low gel time and high viscosity. POLYM. COMPOS. 27:470,474, 2006. © 2006 Society of Plastics Engineers. [source] Mechanical properties and thermal analysis of low-density polyethylene,+,polypropylene blends with dialkyl peroxidePOLYMERS FOR ADVANCED TECHNOLOGIES, Issue 4 2010Kamil, irin Abstract Polypropylene,+,low density polyethylene (PP,+,LDPE) blends involving 0, 25, 50, 75 and 100,wt% of PP with dialkyl peroxide (DAP) were prepared by melt blending in a single-screw extruder. The effects of adding dialkyl peroxide on mechanical and thermal properties of PP,+,LDPE blends have been studied. It was found that at lower concentrations of peroxide (e.g., 0,0.08,wt% of dialkyl peroxide) LDPE component is cross-linked and Polypropylene (PP) is degraded in all compositions of PP,+,LDPE blends. Mechanical properties (Tensile strength at break, at yield and elongation at break), Melt flow index (MFI), hardness, Scanning Electron Microscope (SEM) and thermal analyses (DSC) of these blends were examined. Because of serious degradation or cross-linking the mechanical properties and the crystallinty (%) of those products were decreased as a result of increasing peroxide content. Copyright © 2009 John Wiley & Sons, Ltd. [source] Rapid AFM imaging of large soft samples in liquid with small forces,ASIAN JOURNAL OF CONTROL, Issue 2 2009Szuchi Tien Abstract This article addresses the reduction of the tip-sample force during rapid Atomic Force Microscope (AFM) imaging of large soft samples in liquid medium. Maintaining a small tip-sample force is critical to avoid sample damage, especially when imaging soft biological samples or polymers. The tip-sample force can be reduced if the AFM-probe can be positioned to follow the sample topography as it is scanned over the surface. However, precision positioning over the sample topography has been challenging when imaging relatively large areas in soft samples. A zoom-out/zoom-in iterative method is proposed to achieve the precision positioning needed to maintain small tip-sample forces during rapid AFM imaging. The method is used to demonstrate rapid imaging of soft hydrogel samples. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society [source] Creep and hysteresis compensation for nanomanipulation using atomic force microscopeASIAN JOURNAL OF CONTROL, Issue 2 2009Qinmin Yang Abstract In this paper, a novel scheme is presented to simultaneously compensate the inherent creep and hysteresis nonlinearities of a piezoelectric actuator while positioning the Atomic Force Microscope (AFM) tip. In order to mitigate these nonlinearities, creep and hysteresis phenomenon are first modeled separately by using the classical Prandtl-Ishlinskii (PI) operator. Then, a linear time-invariant (LTI) representation is obtained to identify the creep uncertainty and subsequently an adaptive control scheme is devised for the piezoelectric actuator to track a desired path in the presence of creep. An additional dynamic inversion loop is utilized by using an online approximator to offset the hysteresis effects without the need of identifying the parameters within the hysteresis model. Rigorous performance analysis is conducted using standard Lyapunov stability approach along with simulation results. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society [source] Semi-automatic tuning of PID gains for atomic force microscopesASIAN JOURNAL OF CONTROL, Issue 2 2009Daniel Y. Abramovitch Abstract The control of a typical commercial Atomic Force Microscope (AFM) is through some variant on a Proportional, Integral, Derivative (PID) controller. Typically, the gains are hand tuned so as to keep the bandwidth of the system far below the first resonant frequency of the actuator. This paper shows a straightforward method of selecting PID gains from the actuator model so as to allow considerably higher bandwidths. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society [source] CONTROL ISSUES IN HIGH-SPEED AFM FOR BIOLOGICAL APPLICATIONS: COLLAGEN IMAGING EXAMPLEASIAN JOURNAL OF CONTROL, Issue 2 2004Q. Zou ABSTRACT This article considers the precision positioning problem associated with high-speed operation of the Atomic Force Microscope (AFM), and presents an inversion-based control approach to achieve precision positioning. Although AFMs have high (nanoscale) spatial resolution, a problem with current AFM systems is that they have low temporal resolution, i.e., AFM imaging is slow. In particular, current AFM imaging cannot be used to provide three-dimensional, time-lapse images of fast processes when imaging relatively-large, soft samples. For instance, current AFM imaging of living cells takes 1,2 minutes (per image frame) , such imaging speeds are too slow to study rapid biological processes that occur in seconds, e.g., to investigate the rapid movement of cells or the fast dehydration and denaturation of collagen. This inability, to rapidly image fast biological processes, motivates our current research to increase the operating speed of the AFM. We apply an inversion-based feedback/feedforward control approach to overcome positioning problems that limit the operating speed of current AFM systems. The efficacy of the method, to achieve high-speed AFM operation, is experimentally evaluated by applying it to image collagen samples. [source] Analyzing characteristic length scales in biofilm structuresBIOTECHNOLOGY & BIOENGINEERING, Issue 2 2009K. Milferstedt Abstract The quantification of biofilm structure based on image analysis requires a statistical measure like representative elemental areas (REA) to determine the necessary size of biofilm area to be imaged. In this study, REAs for biofilm structure were calculated for the descriptors Gray level and Correlation (COR) derived from a spatial gray level dependence matrix analysis (SGLDM). An important difference between these two descriptors is their response to structural features at different spatial scales. Gray level is a scale-independent descriptor, whereas COR is scale-dependent. For scale-independent descriptors, the size of the individual images is not relevant when determining REAs. This is in contrast to scale-dependent descriptors for which REAs can only be determined when the area of each image covers the range of structural variability of the biofilm. We used COR to analyze scale dependence of structural heterogeneity at different length scales. A characteristic length of 400 µm in biofilm images provides structural information relevant for mass transport phenomena in biofilms. Overall REAs for gray level and COR were on average 3.4 mm2. The scale-dependent descriptor COR could not in all cases accurately be determined from combining individual image analysis results,even when the combined area resulted in the REA. Microscope and camera specifications define the upper and lower limit of detectable characteristic length that can be extracted from images and should therefore be considered in the experimental design when choosing an imaging technique. Biotechnol. Bioeng. 2009;102: 368,379. © 2008 Wiley Periodicals, Inc. [source] Measuring the Interaction Forces between Protein Inclusion Bodies and an Air Bubble Using an Atomic Force MicroscopeBIOTECHNOLOGY PROGRESS, Issue 5 2001N. D. Wangsa-Wirawan Interaction forces between protein inclusion bodies and an air bubble have been quantified using an atomic force microscope (AFM). The inclusion bodies were attached to the AFM tip by covalent bonds. Interaction forces measured in various buffer concentrations varied from 9.7 nN to 25.3 nN (± 4,11%) depending on pH. Hydrophobic forces provide a stronger contribution to overall interaction force than electrostatic double layer forces. It also appears that the ionic strength affects the interaction force in a complex way that cannot be directly predicted by DLVO theory. The effects of pH are significantly stronger for the inclusion body compared to the air bubble. This study provides fundamental information that will subsequently facilitate the rational design of flotation recovery system for inclusion bodies. It has also demonstrated the potential of AFM to facilitate the design of such processes from a practical viewpoint. [source] The Gene Illusion: Genetic Research in Psychiatry and Psychology under the MicroscopeBRITISH JOURNAL OF LEARNING DISABILITIES, Issue 1 2004Chris Goodey No abstract is available for this article. [source] Nanostructural properties of intraocular lenses (IOLs) , atomic force microscopy (AFM) and Fourier transform infrared spectroscopy (FTIR) investigationsACTA OPHTHALMOLOGICA, Issue 2009E WYLEGALA Purpose To investigate and analyze surface of explanted intraocular lenses (IOL-s), by means of the Atomic Force Microscope (AFM) and Fourier transform infrared spectroscopy (FTIR). Methods Eight dry IOL-s (acrylic: SN60AT , 3 pieces, SA60AT , CZ70BD; silicone: CLRFLXC; "hard": AJPR,CP65T), and four hydrophilic acrylic IOL-s (AC-IOL and PC- IOL, both: naïve and removed during keratoplasty) were imaged (topography and phase) with AFM. AFM is used to investigate, at nanoscale, the surfaces' topography and some nanomechanical properties (eg. elasticity, hardness) of materials in medicine. The samples can be investigated in quasi-physiological conditions, usually no damaging preparation is required. For the acrylic and "hard" lenses the granular nanostructure is observed. The roughness of the lenses' surfaces can be then assessed. The silicone lens is soft: the forces of nanonewtons applied during imaging cause strong deformations of the material. Results Nanomechanical properties of PC-IOL lens are not uniform. This may be advantageous for its calcification: for the lens of the same type removed during keratoplasty strong calcification is observed. For SN60AT lens the influence of the application process (folding) on its nanostructure is tested. The observed structural nano-defects are permanent, they can occur during folding or can be caused by the used equipement. The similar nano-deformations are observed for the removed AC-IOL lens. Conclusion AFM and FTIR showed to be a high-resolution imaging tool for the scanning of surface IOL. [source] Structural hair shaft abnormalities in hypomelanosis of Ito and other ectodermal dysplasiasACTA PAEDIATRICA, Issue 5 2000E Selvaag Hair samples from patients with different ectodermal dysplasias; hypohidrotic ectodermal dysplasia, pachyonychia congenita, tricho-dento-osseous syndrome, tricho-rhino-phalangeal syndrome, and hypomelanosis of Ito were investigated using a scanning electron microscope. The hairs of the patients showed different structural abnormalities; twisted hairs, longitudinal grooves, trichorrhexis nodosa as well as variations in the hair caliber. Hair shaft abnormalities, as in our patients with tricho-dento-osseous syndrome, and hypomelanosis of Ito have so far not been described. [source] Effects of motilin on intracellular free calcium in cultured smooth muscle cells from the antrum of neonatal ratsACTA PHYSIOLOGICA, Issue 1 2010P. Fang Abstract Aim:, The aim of this study was to determine the effects of motilin on [Ca2+]i regulation and its underlying molecular mechanism in cultured antral smooth muscle cells (ASMCs). Methods:, Antral cells were isolated and cultured from neonatal rats, and then the [Ca2+]i in these cells was evaluated by calcium fluorescent probe Fluo-3/AM on a laser scanning confocal microscope. Results:, We show that motilin dose-dependently increased [Ca2+]i concentration in cultured ASMCs. Pre-incubation of cells with either the calcium antagonist verapamil (10,5 mol L,1) or the calcium chelator Egtazic (EGTA, 0.1 mmol L,1) significantly suppressed motilin (10,6 mol L,1) induced [Ca2+]i increase as indicated by fluorescent intensity. Interestingly, after mixing with the non-selective intracellular calcium release blocker TMB-8 (10,5 mol L,1), guanosine triphosphate regulatory protein antagonist NEM (10,5 mol L,1), phospholipase C (PLC) inhibitor compound 48/80 (1.2 ,g mL,1) and ryanodine at high concentration (10,5 mol L,1), the motilin-induced [Ca2+]i increase was only partially blocked. The protein kinase C inhibitor d -sphingosine (10,6 mol L,1), however, did not show any inhibitory effect on motilin-induced [Ca2+]i elevation. Conclusions:, Our study suggests that motilin-stimulated [Ca2+]i elevation in ASMCs is probably due to sustained extracellular Ca2+ influx and Ca2+ release from Ca2+ stores via inositol tris-phosphate receptors and ryanodine receptors. Specifically, motilin-induced [Ca2+]i release is accompanied with guanosine triphosphate-binding protein-coupled receptor,PLC,inositol tris-phosphate signalling cascades. [source] Cobalt release from inexpensive jewellery: has the use of cobalt replaced nickel following regulatory intervention?CONTACT DERMATITIS, Issue 2 2010Jacob Pontoppidan Thyssen Background: Before the introduction of the EU Nickel Directive, concern was raised that manufacturers of jewellery might turn from the use of nickel to cobalt following the regulatory intervention on nickel exposure. Objectives: The aim was to study 354 consumer items using the cobalt spot test. Cobalt release was assessed to obtain a risk estimate of cobalt allergy and dermatitis in consumers who would wear the jewellery. Methods: The cobalt spot test was used to assess cobalt release from all items. Microstructural characterization was made using scanning electron microscope (SEM) and energy-dispersive spectroscopy (EDS). Results: Cobalt release was found in 4 (1.1%) of 354 items. All these had a dark appearance. SEM/EDS was performed on the four dark appearing items which showed tin,cobalt plating on these. Conclusions: This study showed that only a minority of inexpensive jewellery purchased in Denmark released cobalt when analysed with the cobalt spot test. As fashion trends fluctuate and we found cobalt release from dark appearing jewellery, cobalt release from consumer items should be monitored in the future. Industries may not be fully aware of the potential cobalt allergy problem. [source] Synthesis and tribological properties of laminated Ti3SiC2 crystalsCRYSTAL RESEARCH AND TECHNOLOGY, Issue 8 2010Qiong Wu Abstract Laminated Ti3SiC2 crystals are prepared of Ti, Si, C and Al powders by the method of hot isostatic pressing with NaCl additive in argon at 1350 °C. The laminated morphology of Ti3SiC2 is presented through the SEM and TEM observations. The results of high resolution transmission electron microscope (HRTEM) and selected area electron diffraction (SAED) patterns combined, it can be seen that the layers are of Ti3SiC2 crystals. The growth mechanism of Ti3SiC2 crystals, controlled by two-dimensional nucleation, is also explained. The tribological properties of Ti3SiC2 crystals as additives in HVI500 base oil are investigated by a UMT-2 ball-on-plate friction and wear tester. The study shows that under determinate conditions, the friction coefficient of the base oil containing Ti3SiC2 crystals is lower than that of pure base oil, and it decreases with the increase of mass percent of Ti3SiC2 nanolayers when its proportion is lower than 5wt. %. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Laser-induced damage of DKDP crystal under different wavelengthsCRYSTAL RESEARCH AND TECHNOLOGY, Issue 7 2010Mingxia Xu Abstract In this paper, DKDP crystals were grown from 80% deuterated solution by traditional temperature-reduction method. The crystal samples were selected to test laser damage threshold (LDT) and laser conditioning of 1,, 2, and 3,. We found that the laser conditioning of 3, has much more effect on improving the LDT. The damage site was observed by microscope and its effects on micro-structure and optical properties were also studied. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] | ||||||||||||||||||||||||||||||||||||||||||||||