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Wavelength
Kinds of Wavelength Terms modified by Wavelength Selected AbstractsPhotoepilation Results of Axillary Hair in Dark-Skinned Patients by IPL: A Comparison Between Different Wavelength and Pulse WidthDERMATOLOGIC SURGERY, Issue 2 2006JONG HEE LEE MD BACKGROUND Recently, intense pulsed light (IPL) sources have been shown to provide long-term hair removal. OBJECTIVE This study examined the photoepilatory effects of different wavelengths and pulse width application in the same device and compared their efficiencies in Asian skin. METHODS Twenty-eight Korean women were treated using HR (600,950 nm filter) and 27 using HR-D (645,950 nm filter) in the axillar area. Four treatments were carried out at intervals of 4 to 6 weeks; follow-ups were conducted 8 months after the last treatment. Mean energy settings were 14.9±2.0 J/cm2 for HR and 17.1±0.6 J/cm2 for HR-D. Longer pulse widths were applied in case of HR-D treatment. Hair counts and photographic evaluation of skin sites were made at baseline and at the last follow-up. Final overall evaluations were performed by patients and clinicians. RESULTS Average clearances of 52.8% and 83.4% were achieved by HR and HR-D, respectively. No significant adverse effects were reported after HR-D treatment. One case each of hypopigmentation and hyperpigmentation was reported for HR. CONCLUSION An IPL source by removing 45 nm of the emitted spectra and applying longer pulse width was found to provide a safer and more effective means of photoepilation in Asian patients. [source] Efficient Photosensitization and High Optical Gain in a Novel Quantum-Dot-Sensitized Hybrid Photorefractive Nanocomposite at a Telecommunications Wavelength,ADVANCED FUNCTIONAL MATERIALS, Issue 5 2005Choudhury, K. Roy Abstract A high-performance hybrid polymeric photorefractive nanocomposite operating at the telecommunications wavelength of 1.34,,m is presented. The photorefractive nanocomposite is sensitized with PbS nanocrystals synthesized via a hot colloidal route. Photoconductivity experiments confirm and quantify the photocharge-generation quantum efficiency of the nanocrystals. A pronounced two-beam coupling effect at the operation wavelength is observed, leading to very high optical gains. Temporal evolution of the photorefractive growth process is also studied. [source] Bulk Photovoltaic Effect at Visible Wavelength in Epitaxial Ferroelectric BiFeO3 Thin FilmsADVANCED MATERIALS, Issue 15 2010Wei Ji Appreciable photovoltaic responses to visible light are observed in epitaxial ferroelectric BiFeO3 thin films by sputtering deposition. The photocurrent direction is opposite to the BiFeO3 polarization vector and can be switched by poling the films in different directions (see figure). The as-deposited films are strongly self-polarized, exhibiting significant photovoltaic response before any electrical poling process. [source] Spatially Localized Photoluminescence at 1.5 Micrometers Wavelength in Direct Laser Written Optical NanostructuresADVANCED MATERIALS, Issue 23 2008Sean Wong No abstract is available for this article. [source] More than one Wavelength: Identifying, Understanding and Resolving Conflicts of Interest between People with Intellectual Disabilities and their Family CarersJOURNAL OF APPLIED RESEARCH IN INTELLECTUAL DISABILITIES, Issue 1 2001V. Williams The present paper describes conflicts of interest in families which include someone with intellectual disabilities. Data were taken from a study concerned with the 1995 Carers Act. The research examined the experiences and views of 51 families who had some kind of assessment by a social services department. Cases were analysed where it was found that carers, the people for whom they cared and the assessors did not agree about such conflicts. Assessors sometimes stereotyped families and spoke of conflicts of interest when the situation was more complex. In particular, the real conflict was often between the whole family and an inadequate service system that did not offer enough support or choices to the individual. Conflicts which had occurred were related to three major motives driving carers: (1) the need for a break from caring; (2) the need to speak for their disabled relative; and (3) their concern for standards of behaviour. The present authors report on how these situations were handled by assessors and conclude with some recommendations for good carer assessments which will help to resolve conflicts of interest. A greater degree of informed choice for individuals with intellectual disabilities will in itself resolve many potential conflicts of interest. [source] Quantum Yield of the Iodide,Iodate Chemical Actinometer: Dependence on Wavelength and Concentration,PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 2 2003Ronald O. Rahn ABSTRACT The quantum yield (QY) of the iodide,iodate chemical actinometer (0.6 M KI,0.1 M KIO3) was determined for irradiation between 214 and 330 nm. The photoproduct, triiodide, was determined from the increase in absorbance at 352 nm, which together with a concomitant measurement of the UV fluence enabled the QY to be calculated. The QY at 254 nm was determined to be 0.73 ± 0.02 when calibration was carried out against a National Institute of Standards and Technology traceable radiometer or photometric device. At wavelengths below 254 nm the QY increased slightly, leveling off at ,0.80 ± 0.05, whereas above 254 nm the QY decreases linearly with wavelength, reaching a value of 0.30 at 284 nm. In addition, the QY was measured at different iodide concentrations. There is a slight decrease in QY going from 0.6 to 0.15 M KI, whereas below 0.15 M KI the QY drops off sharply, decreasing to 0.23 by 0.006 M KI. Calibration of the QY was also done using potassium ferrioxalate actinometry to measure the irradiance. These results showed a 20% reduction in QY between 240 and 280 nm as compared with radiometry. This discrepancy suggests that the QY of the ferrioxalate actinometer in this region of the spectrum needs reexamination. [source] The Treatment of Melasma with Fractional Photothermolysis: A Pilot StudyDERMATOLOGIC SURGERY, Issue 12 2005Cameron K. Rokhsar MD Background. Melasma is a common pigmentary disorder that remains resistant to available therapies. Facial resurfacing with the pulsed CO2 laser has been reported successful but requires significant downtime, and there is a risk of adverse sequelae. Objective. To determine if melasma will respond to a new treatment paradigm, fractional resurfacing. Methods. Ten female patients (Fitzpatrick skin types III,V) who were unresponsive to previous treatment were treated at 1- to 2-week intervals with the Fraxel laser (Reliant Technologies, Palo Alto, CA, USA). Wavelengths of 1,535 and 1,550 nm were both used, and 6 to 12 mJ per microthermal zone with 2,000 to 3,500 mtz/cm2 were the treatment parameters. Four to six treatment sessions were performed. Responses were evaluated according to the percentage of lightening of original pigmentation. Two physicians evaluated the photographs, and each patient evaluated her own response. Results. The physician evaluation was that 60% of patients achieved 75 to 100% clearing and 30% had less than 25% improvement. The patients' evaluations agreed, except for one patient, who graded herself as 50 to 75% improved as opposed to the physician grading of over 75%. There was one patient with postinflammatory hyperpigmentation and no patient with hypopigmentation. No downtime was necessary for wound healing. Conclusions. Fractional resurfacing affords a new treatment algorithm for the treatment of melasma that combines decreased risk and downtime with significant efficacy. This treatment modality deserves further exploration to maximize benefits. RELIANT technologies LOANED THE FRAXEL LASER FOR THE STUDY. RICHARD E. FITZPATRICK, MD, IS A PAID CONSULTANT FOR RELIANT AND A STOCKHOLDER. [source] Surface Plasmonics: Plasmonic Crystals: A Platform to Catalog Resonances from Ultraviolet to Near-Infrared Wavelengths in a Plasmonic Library (Adv. Funct.ADVANCED FUNCTIONAL MATERIALS, Issue 4 2010Mater. Research in the field of surface plasmonics is finding application in many areas; for example, in data storage, nano-electronics, and biosensing. In their feature article on page 529, H. Gao et al. describe recent progress in manipulating surface plasmons from the ultraviolet to near-infrared wavelengths using nanostructured plasmonic crystals (shown in the cover image), and build a comprehensive library of plasmonic resonances, bringing together for the first time the resonance characteristics of key plasmonic materials. [source] Plasmonic Crystals: A Platform to Catalog Resonances from Ultraviolet to Near-Infrared Wavelengths in a Plasmonic LibraryADVANCED FUNCTIONAL MATERIALS, Issue 4 2010Hanwei Gao Abstract Surface plasmons are responsible for a variety of phenomena, including nanoscale optical focusing, negative refraction, and surface-enhanced Raman scattering. Their characteristic evanescent electromagnetic fields offer opportunities for sub-diffraction imaging, optical cloaking, and label-free molecular sensing. The selection of materials for such applications, however, has been traditionally limited to the noble metals Au and Ag because there has been no side-by-side comparison of other materials. This feature article describes recent progress on manipulating surface plasmons from ultraviolet to near-infrared wavelengths using plasmonic crystals made from 2D nanopyramidal arrays. A library of plasmon resonances is constructed in the form of dispersion diagrams for a series of unconventional and new composite plasmonic materials. These resonances are tuned by controlling both intrinsic factors (unit cell shape, materials type) and extrinsic factors (excitation conditions, dielectric environment). Finally, plasmonic crystals with reduced lattice symmetries are fabricated as another means to tailor resonances for broadband coupling. [source] Formation of Silver Nanoprisms with Surface Plasmons at Communication Wavelengths,ADVANCED FUNCTIONAL MATERIALS, Issue 6 2006V. Bastys Abstract Silver nanoprisms with strong absorption in the near-IR have been synthesized using a modification of the photoinduced method by illuminating preformed silver seeds under different illumination conditions. Low-intensity light-emitting diodes and white light combined with different color filters are used as light sources. The lateral dimensions of the nanoprisms are found to be correlated in a quasilinear fashion with the emission wavelength and the position of the main in-plane dipole plasmon band. The structural characterization of the Ag nanoparticles, carried out using scanning electron microscopy, transmission electron microscopy (TEM), high-resolution TEM, and electron diffraction, reveal that the particles are flat and have a single-crystal face-centered-cubic structure. Time-resolved studies suggest that the nanoprisms are formed by steady consumption of the original Ag seeds with little variation of the aspect ratio after a short induction time. [source] Log-Pile TiO2 Photonic Crystal for Light Control at Near-UV and Visible WavelengthsADVANCED MATERIALS, Issue 4 2010Ganapathi Subramania Three-dimensional photonic crystals with an omnidirectional bandgap at visible frequencies can have significant impact on solid-state lighting and solar-energy conversion. Using a procedure based on multistep electron-beam lithographic processing, a 9-layer log-pile photonic crystal is fabricated composed of 70-nm-wide titanium dioxide rods with 250-nm lattice spacing that exhibit a stacking direction bandgap between 400,nm and 500,nm (see image). [source] Two-Photon Absorption-Related Properties of Functionalized BODIPY Dyes in the Infrared Range up to Telecommunication WavelengthsADVANCED MATERIALS, Issue 10-11 2009Pierre-Antoine Bouit Aza boron-dipyrromethene dyes functionalized by extended donor-,-conjugated moieties present high potentialities for nonlinear applications in the telecommunication spectral range (1300,1500,nm). Their significant two-photon absorption cross-sections (,2,>,600 GM) over this entire spectral range, combined with their high stability and solubility, allow nonlinear transmission experiments. [source] Controlling Light Oxidation Flavor in Milk by Blocking Riboflavin Excitation Wavelengths by InterferenceJOURNAL OF FOOD SCIENCE, Issue 9 2009J.B. Webster ABSTRACT:, Milk packaged in glass bottles overwrapped with iridescent films (treatments blocked either a single visible riboflavin [Rb] excitation wavelength or all visible Rb excitation wavelengths; all treatments blocked UV Rb excitation wavelengths) was exposed to fluorescent lighting at 4 °C for up to 21 d and evaluated for light-oxidized flavor. Controls consisted of bottles with no overwrap (light-exposed treatment; represents the light barrier properties of the glass packaging) and bottles overwrapped with aluminum foil (light-protected treatment). A balanced incomplete block multi-sample difference test, using a ranking system and a trained panel, was used for evaluation of light oxidation flavor intensity. Volatiles were evaluated by gas chromatography and Rb degradation was evaluated by fluorescence spectroscopy. Packaging overwraps limited production of light oxidation flavor over time but not to the same degree as the complete light block. Blocking all visible and UV Rb excitation wavelengths reduced light oxidation flavor better than blocking only a single visible excitation wavelength plus all UV excitation wavelengths. Rb degraded over time in all treatments except the light-protected control treatment and only minor differences in the amount of degradation among treatments was observed. Hexanal production was significantly higher in the light-exposed control treatment compared to the light-protected control treatment from day 7; it was only sporadically significantly higher in the 570 nm and 400 nm block treatments. Pentanal, heptanal, and an unidentified volatile compound also increased in concentration over time, but there were no significant differences in concentration among the packaging overwrap treatments for these compounds. [source] Simple and sensitive HPLC method for determination of amrubicin and amrubicinol in human plasma: application to a clinical pharmacokinetic studyBIOMEDICAL CHROMATOGRAPHY, Issue 3 2010Reiko Ando Abstract A simple and sensitive high-performance liquid chromatographic (HPLC) method was developed for determination of amrubicin and its metabolite amrubicinol in human plasma. After protein precipitation with methanol without evaporation procedure, large volume samples were injected and separated by two monolithic columns with a guard column. The mobile phase consisted of tetrahydrofuran,dioxane,water (containing 2.3,mM acetic acid and 4,mM sodium 1-octanesulfonate; 2:6:15, v/v/v). Wavelengths of fluorescence detection were set at 480,nm for excitation and 550,nm for detection. Under these conditions, linearity was confirmed in the 2.5,5000,ng/mL concentration range of both compounds. The intra- and inter-day precision and intra- and inter-day accuracy for both compounds were less than 10%. The method was successfully applied to a clinical pharmacokinetic study of amrubicin and amrubicinol in cancer patients. Copyright © 2009 John Wiley & Sons, Ltd. [source] Anomalous Dispersion in Predictive RenderingCOMPUTER GRAPHICS FORUM, Issue 4 2009Andrea Weidlich Abstract In coloured media, the index of refraction does not decrease monotonically with increasing wavelength, but behaves in a quite non-monotonical way. This behaviour is called anomalous dispersion and results from the fact that the absorption of a material influences its index of refraction. So far, this interesting fact has not been widely acknowledged by the graphics community. In this paper, we demonstrate how to calculate the correct refractive index for a material based on its absorption spectrum with the Kramers-Kronig relation, and we discuss for which types of objects this effect is relevant in practice. [source] Effect of Oscillating Sheath on Near-Wall Electron Current Profile in Hall ThrustersCONTRIBUTIONS TO PLASMA PHYSICS, Issue 9-10 2008D. R. Yu Abstract The radial profile of the axial electron current in Hall thrusters was measured; however, the significant decay of the current density peak in the near-wall region can't be explained effectively by the steady sheath theory. As the sheath exhibits an oscillating character when the thruster is in operation, its effect on the near-wall current profile has been studied in this paper. To obtain a comprehensive knowledge, we have considered a wide sheath oscillation frequency span which includes two asymptotic frequency cases at high and low ends. Based on the case studied, either an analytical treatment or a numerical simulation is applied. The results show that the current density peak has a fastest damping speed away from the wall at the asymptotic low frequency. With the increase of the frequency, both the decay and the spatial "wavelength" of the current profile decrease. The decay finally disappears at the asymptotic high frequency with a constant spatial "wavelength". Moreover, the sheath oscillation amplitude can enhance the decay and enlarge the spatial "wavelength". Taking into account of the realistic situation in Hall thrusters, the significant impact of the oscillating sheath on the near-wall electron current profiles can be anticipant. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Effect of reduction/oxidation treatment on blue photorefraction in In:Fe:Cu:LiNbO3 crystalsCRYSTAL RESEARCH AND TECHNOLOGY, Issue 4 2010Suhua Luo Abstract In:Fe:Cu:LiNbO3 crystals with reduced/oxidized treatments were prepared by the Czochralski method. The defect structure was analyzed by the UV-Visible absorption spectra. The blue photorefractive properties, such as the refractive index change, response time, recording sensitivity, dynamic range as well as two-wave coupling gain coefficient, were also investigated at 488 nm wavelength using the two-wave coupling experiment. Comparing the as-grown and oxidized In:Fe:Cu:LiNbO3 crystals, the reduced sample has the highest recording sensitivity and largest dynamic range. Meanwhile, the high diffraction efficiency is still maintained. Experimental results definitely show that reduction treatment is an effective method to improve the blue photorefractive performance of In:Fe:Cu:LiNbO3 crystals. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Temperature-tuned band gap energy and oscillator parameters of Tl2InGaSe4 semiconducting layered single crystalsCRYSTAL RESEARCH AND TECHNOLOGY, Issue 3 2009N. M. Gasanly Abstract The optical properties of Tl2InGaSe4 layered single crystals have been studied through the transmission and reflection measurements in the wavelength range of 500-1100 nm. The analysis of room temperature absorption data revealed the presence of both optical indirect and direct transitions with band gap energies of 1.86 and 2.05 eV, respectively. Transmission measurements carried out in the temperature range of 10-300 K revealed that the rate of change of the indirect band gap with temperature is , = , 4.4 × 10 -4 eV/K. The absolute zero value of the band gap energy was obtained as Egi(0) = 1.95 eV. The dispersion of the refractive index is discussed in terms of the single oscillator model. The refractive index dispersion parameters: oscillator wavelength and strength were found to be 2.53 × 10,7 m and 9.64 × 1013 m,2, respectively. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Laser-induced crystal growth of nonlinear optical Ba3Ti3O6(BO3)2 on glass surfaceCRYSTAL RESEARCH AND TECHNOLOGY, Issue 12 2008T. Oikawa Abstract Nonlinear optical Ba3Ti3O6(BO3)2 crystals were patterned on the surface of CuO (1 mol%)-doped 40BaO-40TiO2 -20B2O3 glass by irradiations of continuous-wave Nd:YAG (wavelength: ,=1064 nm) and Yb:YVO4 (,=1080 nm) lasers. Laser energies absorbed by Cu2+ ions were transferred to the lattice system through a nonradiative relaxation process, consequently heating the glass and inducing local crystallizations. For the lines patterned by Yb:YVO4 laser irradiations with a power of 1 W and a scanning speed of 20 ,m/s, a c -axis orientation of Ba3Ti3O6(BO3)2 crystals along the laser scanning direction is proposed from measurements of X-ray diffraction analyses, polarized optical photographs, polarized micro-Raman scattering spectra, and azimuthal dependence of second harmonic generations. The laser-induced crystallization technique is found to be applied successfully for the spatially selective patterning of nonlinear optical Ba3Ti3O6(BO3)2 crystals in glass. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Influence of Mg/Er co-doping on the principal laser parameters of LiNbO3 crystalsCRYSTAL RESEARCH AND TECHNOLOGY, Issue 7 2007Liang Sun Abstract Mg: Er: LiNbO3 crystals were grown by the Czochralski technique with various concentrations of MgO = 2 mol%, 4 mol%, 6 mol% and the fixed concentration of Er2O3= 1 mol% in the melt, and the 8 mol%Mg: 1 mol%Er: LiNbO3 crystal was fabricated by the Czochralski technique with special technology process. The crystals were treated by polarization, reduction and oxidation. The segregation coefficients of Mg2+ and Er3+ in Mg: Er: LiNbO3 crystals were measured by X-ray fluorescence spectrograph, as well as the crystal's defect structure and optical properties were analyzed by the UV-Vis, IR and fluorescent spectroscopy. The pump wavelength and the surge wavelength were determined. Using m-line method tested optical damage resistance of those crystals, the results show that photodamage threshold of Mg: Er: LiNbO3 crystals are higher than that of Er: LiNbO3 crystal, and the oxidation treat could enhance the photodamage resistant ability of crystals while the reduction treat could depress the ability. The optical damage resistance of 8 mol%Mg: 1 mol%Er: LiNbO3 crystal was the strongest among the samples, which was two orders magnitude higher than that of 1 mol%Er: LiNbO3 crystal. The dependence of the optical properties on defect structure of Mg: Er: LiNbO3 crystals was discussed. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Physical properties of Dy and La doped SnO2 thin films prepared by a cost effective vapour deposition techniqueCRYSTAL RESEARCH AND TECHNOLOGY, Issue 10 2006J. Joseph Abstract Stannous oxide (SnO2) thin film is one of the most widely used n-type transparent semi-conductor films in electronics, electro-optics and solar energy conversion. By achieving controlled non-stoichiometry, we can get good transparency and high electrical conductivity simultaneously in SnO2 thin films. Dy and La doped SnO2 thin films have been prepared by a cost effective vapour deposition technique. The structural, photo-electronic, optical and electrical properties of the doped and undoped films were studied. The results of X-ray Diffraction studies reveals the polycrystalline nature of the films with preferential orientation along the (101), (211) and (301) planes and their average grain size variation for different deposition temperature. Photoconductivity and Photovoltaic studies of the films were also performed. The optical properties of these films were studied by measuring their optical transmission as a function of wavelength. The optical transmission is found to be increased on Dy doping and decreased on La doping. The band gap, refractive index and thickness of the films were calculated from U-V transmittance and Absorption graphs. The optical band gap of undoped film is found to be 4.08 eV, but on doping it shifts to lower energies and then increases on increasing the concentration of both dopants. Its electrical parameters such as sheet resistance, resistivity, mobility, Hall coefficient, and carrier concentration were determined by Four Probe, Van der Pauw and Hall Probe method. On doping with Dy, carrier conversion takes place from n-type to p-type and p-conductivity dominates. On La doping no carrier conversion takes place but resistivity decreases. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Preparation and characterization of electrodeposited indium selenide thin filmsCRYSTAL RESEARCH AND TECHNOLOGY, Issue 6 2005S. Gopal Abstract Indium Selenide (InSe) thin films were deposited from a mixture of Indium chloride and selenium dioxide in aqueous solution by electrodeposition technique on Indium Tin oxide coated glass substrates. The effects of the parameters during deposition such as current density, deposition potential versus saturated calomel electrode, pH value and concentration of source material were studied. X-ray diffraction studies were carried out on the films to analyze the microstructure using an x-ray diffractometer and were examined by RAMAN spectroscopy. The Raman peak position did not change much with chemical concentrations. Raman scattering due to the (LO) phonon was observed at 211 cm,1. Optical absorption studies were performed with a double beam ultra violet-visible ,NIR spectrophotometer in the wavelength 300,1100 nm. The surface morphology of the layer was examined using a scanning electron micrograph. The composition of the films was studied using an Energy Dispersive Analysis by X-Rays (EDAX). [source] Transmission spectra of crystals at elevated temperatures for the calculation of internal radiant heat transport during crystal growth , Part 1: The spectrometer and its performanceCRYSTAL RESEARCH AND TECHNOLOGY, Issue 10 2003D. Schwabe Abstract We report the construction, operation and performance of a transmission spectrometer for the visible to the IR (up to 3.5 ,m wavelength) to measure crystals up to a temperature of 1400 °C. The spectral resolution is almost comparable to that of a commercial spectrometer. The performance of the spectrometer and some problems are demonstrated by spectra of YAG : Nd at different temperatures. (© 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] In situ observation experiment for semiconductor solution growth under reduced convection condition , a reviewCRYSTAL RESEARCH AND TECHNOLOGY, Issue 7-8 2003Yuko Inatomi Abstract Morphological stability of solid/liquid interface in semiconductor crystal growth from solution has been investigated using a near-infrared microscopic interferometer under a reduced convection condition by authors and Prof. Benz's group. In the result, step kinetic coefficient of the interface of GaP/GaP(111)B in liquid phase epitaxy growth was obtained and the estimated value of macrostep wavelength agreed well with the measured one. [source] Actin stress fiber pre-extension in human aortic endothelial cellsCYTOSKELETON, Issue 4 2008Lan Lu Abstract Actin stress fibers (SFs) enable cells to sense and respond to mechanical stimuli and affect adhesion, motility and apoptosis. We and others have demonstrated that cultured human aortic endothelial cells (HAECs) are internally stressed so that SFs are pre-extended beyond their unloaded lengths. The present study explores factors affecting SF pre-extension. In HAECs cultured overnight the baseline pre-extension was 1.10 and independent of the amount of cell shortening. Decreasing contractility with 30 mM BDM or 10 ,M blebbistatin decreased pre-extension to 1.05 whereas increasing contractility with 2 nM calyculin A increased pre-extension to 1.26. Knockdown of ,-actinin-1 with an interfering RNA increased pre-extension to 1.28. None of these affected the wavelength of the buckled SFs. Pre-extension was the same in unperturbed cells as in those in which the actin cytoskeleton was disrupted by both chemical and mechanical means and then allowed to reassemble. Finally, disrupting MTs or IFs did not affect pre-extension but increased the wavelength. Taken together, these results suggest that pre-extension of SFs is determined primarily by intrinsic factors, i.e. the level of actin-myosin interaction. This intrinsic control of pre-extension is sufficiently robust that pre-extension is the same even after the actin cytoskeleton has been disrupted and reorganized. Unlike pre-extension, the morphology of the compressed SFs is partially determined by MTs and IFs which appear to support the SFs along their lengths. Cell Motil. Cytoskeleton 2008. © 2008 Wiley-Liss, Inc. [source] Na+/Ca2+ exchanger modulates the flagellar wave pattern for the regulation of motility activation and chemotaxis in the ascidian spermatozoaCYTOSKELETON, Issue 10 2006Kogiku Shiba Abstract Ion channels and ion exchangers are known to be important participants in various aspects of sperm physiology, e.g. motility activation, chemotaxis, the maintenance of motility and the acrosome reaction in the sperm. We report here on a role of the K+ -independent Na+/Ca2+ exchanger (NCX) on ascidian sperm. Reverse-transcriptase PCR reveals that the NCX is expressed in the testis while immunoblotting and immunolocalization demonstrate that the NCX exists on the sperm in the ascidian Ciona savignyi and C. intestinalis. A potent blocker of the NCX, KB-R7943 was found to block sperm-activating and -attracting factor (SAAF)-induced motility activation, sperm motility and sperm chemotaxis. We further analyzed the effects of this blocker on motility parameters such as the flagellar waveform, curvature, beat frequency, amplitude and wavelength of the sperm flagella. Inhibition of the NCX caused two distinct effects: a low concentration of KB-R7943 induced symmetric bending, whereas a high concentration of KB-R7943 resulted in asymmetric flagellar bending. These findings suggest that the NCX plays important roles in the regulation of SAAF-induced sperm chemotaxis, motility activation and motility maintenance in the ascidian. This study provides new information toward an understanding of Ca2+ transport systems in sperm motility and chemotaxis. Cell Motil. Cytoskeleton 2006. © 2006 Wiley-Liss, Inc. [source] Efficacy of the Flashlamp-Pumped Pulsed-Dye Laser in Nonsurgical Delay of Skin FlapsDERMATOLOGIC SURGERY, Issue 7 2003Ali Riza Erçöçen MD Objective. The purpose of this article was to determine the effectiveness of laser delay by use of the flashlamp-pumped pulsed-dye laser operating at a wavelength of 585 nm; to elucidate the comparable or dissimilar macroscopic, microscopic, and hemodynamic changes between laser and surgical delay methods; and to clarify the possible mechanisms underlying the delay effect of laser. Methods. A standardized caudally based random dorsal rat flap model was used in this study: Acute random skin flaps served as control subjects (group 1). Surgical delay was employed by incision of lateral longitudinal borders both without (group 2) and with (group 3) undermining, and laser delay methods were performed by laser irradiation of both lateral longitudinal borders (group 4) and the entire surface (group 5) of the proposed flap. Evaluation was done by histologic examination, India ink injection, laser Doppler perfusion imaging, and measurement of flap survival. Results. Histologically, dilation and hypertrophy of subpapillary and subdermal vessels were evident in groups 2, 3, and 4; on the other hand, degranulation of mast cells in the vicinity of occluded vessels at the 1st hour of laser delay and a striking mast cell proliferation and degranulation in association with newly formed vessels (angiogenesis) at the 14th day of laser delay were prominent in group 5. India ink injections revealed longitudinally arranged large-caliber vessels and cross-filling between the vessels of adjacent territories in groups, 2, 3, and 4, but only small-caliber vessels in group 5. Compared with the acute flaps, both surgical and laser delay significantly increased the mean flap perfusion to the maximal levels after a 14-day delay period, and all delay procedures improved flap survival; the most significant increase in surviving area was observed in group 3, whereas the less significant increase in surviving area was in group 5. Conclusion. This study demonstrates that laser delay is as effective as surgical delay and that laser delay by lasering lateral borders leads to dilation and longitudinal rearrangement of the existing vessels rather than angiogenesis, whereas laser delay by lasering the entire surface results in delay effect by inducing angiogenesis due to activation and degranulation of the mast cells. [source] Laser Hair Removal: Long-Term Results with a 755 nm Alexandrite LaserDERMATOLOGIC SURGERY, Issue 11 2001Sorin Eremia MD Background. Hypertrichosis is a common problem for which laser hair removal is becoming the treatment of choice. Optimal wavelength, pulse duration, spot size, fluence, and skin cooling parameters for various skin types have not yet been firmly established. Objective. To evaluate the long-term efficacy and safety of a 3-msec 755 nm alexandrite laser equipped with a cryogen cooling device for patients with Fitzpatrick skin types I,V. Methods. Eighty-nine untanned patients with skin types I,V underwent a total of 492 treatments of laser hair removal over a 15-month period. Each patient in the study underwent a minimum of three treatment sessions spaced 4,6 weeks apart (mean treatments 5.6). Retrospective chart review and patient interviews were used to establish hair reduction results. Treatment sites included the axillae, bikini, extremities, face, and trunk. A 3-msec pulse width, 755 nm alexandrite laser equipped with a cryogen spray cooling device was used in this study. Spot sizes of 10,15 mm were used. A spot size of 10 mm was used for fluences greater than 40 J/cm2, a spot size of 12 mm was used for fluences of 35,40 J/cm2, and spot sizes of 12 and 15 mm were used for fluences less than 30 J/cm2. Fluences ranging from 20 to 50 J/cm2 (mean fluence 36 J/cm2) were used. Results. The patients had a mean 74% hair reduction. Skin type I patients had an average of 78.5% hair reduction using a mean fluence of 40 J/cm2 (35,50 J/cm2) and a 10,12 mm spot size (12 mm in more than 95% of treatments). Skin type II patients had a mean 74.3% hair reduction using a mean fluence of 38 J/cm2 (30,40 J/cm2) and a 12,15 mm spot size. Skin type III patients had a mean 73.4% hair reduction using a mean fluence of 37 J/cm2 (25,40 J/cm2) and a 12,15 mm spot size. Skin type IV patients had a mean 71.0% hair reduction using a mean fluence of 31 J/cm2 (25,35 J/cm2) and a 12,15 mm spot size. A patient with skin type V had a 60% hair reduction using a mean fluence of 23 J/cm2 (20,25 J/cm2) and a 12,15 mm spot size. The efficiency of hair removal directly correlates significantly with the fluence used. Rare side effects included transient postinflammatory hyperpigmentation (n = 9; 10%), burn with blisters (n = 1; 1%), and postinflammatory hypopigmentation (n = 2; 2%). All complications resolved without permanent scarring. Conclusion. The 3-msec cryogen cooling-equipped alexandrite laser can safely and effectively achieve long-term hair removal in patients with skin types I,V. The best results are achieved in untanned patients with skin types I,IV. [source] Laser Hair Removal with Alexandrite versus Diode Laser Using Four Treatment Sessions: 1-Year ResultsDERMATOLOGIC SURGERY, Issue 11 2001Sorin Eremia MD Background. Laser hair removal is the treatment of choice for hypertrichosis. The two most commonly used hair removal lasers are compared. Objective. To present the results of a comparative study examining the role of wavelength, fluence, spot size, pulse width, and cooling systems on long-term results after a series of four laser hair removal treatments using the 755 nm alexandrite and 800,810 nm diode lasers. Methods. The axillae of 15 untanned, type I,V patients were treated side by side four times at 4- to 6-week intervals with a 755 nm, 3-msec pulse width, cryogen spray-equipped alexandrite laser and an 800 nm, variable pulse width, cooled sapphire window-equipped diode laser. Each patient was pretested and treated with the maximum fluence tolerated at the largest spot size available for each laser (12 mm round/113 mm2 for the alexandrite and 9 mm for the diode). Results. Evaluations were done at 3, 6, 9, and 12 months after the last treatment. Twelve-month results with the alexandrite and diode lasers achieved 85% versus 84% hair reduction. The fact that tan avoidance was strictly followed permitted the use of relatively high fluences (25,30+ J/cm2) even in type IV patients. For most patients, four treatment sessions using high fluences (30,40 J/cm2) with relatively large spot sizes (12 mm round for the 755 nm alexandrite and 9 mm for the 800 nm diode) resulted in 12-month hair reductions in the 90% range. Conclusion. Both the alexandrite and diode lasers in this 12-month study produced excellent long-term hair reductions. [source] Laser-Assisted Hair Transplantation: Histologic Comparison Between CO2 and Ho:YAG LasersDERMATOLOGIC SURGERY, Issue 4 2001Eugene A. Chu MD Background. Various laser wavelengths and devices have been advocated for use in the creation of recipient channels during hair transplant surgery, including flash-scanned CO2, Ho:YAG (, = 2.12 ,m), and Er:YAG (, = 2.94 ,m). Objective. To determine the tissue injury caused by flash-scanned CO2 and pulsed Ho:YAG lasers during the creation of hair transplant recipient channels and to assess the efficacy of the Ho:YAG laser. Methods. Recipient channels were created in vivo in human scalp tissue using both lasers, and were excised and prepared for histologic examination. Optical micrometry of tissue sections was used to assess thermal injury. Results. The Ho:YAG laser created jagged, irregular-shaped channels with larger zones of thermal injury (superficial deepithelialization, thermal necrosis, and thermal damage). In contrast, the CO2 laser produced well-defined cylindrically shaped channels free of cellular debris with minimal epithelial disruption and significantly less lateral thermal injury. Conclusion. Given that the Ho:YAG produced larger regions of thermal injury and recipient channels that were unacceptable for graft, the CO2 laser remains the better choice for the creation of recipient channels during hair transplant surgery. However, ongoing research will be necessary to determine the optimal laser wavelength and/or devices for this procedure. [source] | ||||||||||||||||||||||||||||||||||||||||||||||