95 results on '"Lasers statistics & numerical data"'
Search Results
2. Salmon lice survive the straight shooter: A commercial scale sea cage trial of laser delousing.
- Author
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Bui S, Geitung L, Oppedal F, and Barrett LT
- Subjects
- Animals, Ectoparasitic Infestations parasitology, Ectoparasitic Infestations prevention & control, Fish Diseases parasitology, Norway, Aquaculture methods, Copepoda physiology, Ectoparasitic Infestations veterinary, Fish Diseases prevention & control, Lasers statistics & numerical data, Salmo salar
- Abstract
Ectoparasitic salmon louse (Lepeophtheirus salmonis) infestations are costly for Atlantic salmon (Salmo salar) farmers in Norway. As a result, there is a strong desire for solutions to prevent and control infestations, and new technologies are typically developed and commercialised rapidly, without rigorous validation. Here, we tested the efficacy of a new commercially available control measure-delousing by underwater lasers-using a replicated design at full commercial scale. Laser delousing was used in combination with a preventive method (snorkel cages), with laser nodes deployed in 3 of the 6 sea cages at the site. The trial ran for 54 days, after which time there was no difference in infestation density of mobile salmon louse stages (pre-adult, adult male or adult female) in cages with or without laser nodes installed. By the end of the trial, adult female lice numbers in all cages were close to the legislated trigger for mandatory delousing (0.5 adult female lice per fish). The laser nodes delivered a large number of pulses relative to the number of lice in the cages, indicating that a lack of lethality rather than a lack of target detection was the limiting factor. If all pulses had been effective, they should have removed between 4-38 % of mobile lice each day. There was no effect on salmon welfare indicators such as skin condition or eye status. Our results highlight the importance of rigorous validation of new technologies across a range of conditions before widespread implementation by industry., (Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.)
- Published
- 2020
- Full Text
- View/download PDF
3. Experimental Methods for Spin- and Angle-Resolved Photoemission Spectroscopy Combined with Polarization-Variable Laser.
- Author
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Kuroda K, Yaji K, Harasawa A, Noguchi R, Kondo T, Komori F, and Shin S
- Subjects
- Lasers statistics & numerical data, Photoelectron Spectroscopy methods
- Abstract
The goal of this protocol is to present how to perform spin- and angle-resolved photoemission spectroscopy combined with polarization-variable 7-eV laser (laser-SARPES), and demonstrate a power of this technique for studying solid state physics. Laser-SARPES achieves two great capabilities. Firstly, by examining orbital selection rule of linearly polarized lasers, orbital selective excitation can be carried out in SAPRES experiment. Secondly, the technique can show full information of a variation of the spin quantum axis as a function of the light polarization. To demonstrate the power of the collaboration of these capabilities in laser-SARPES, we apply this technique for the investigations of spin-orbit coupled surface states of Bi2Se3. This technique affords to decompose spin and orbital components from the spin-orbit coupled wavefunctions. Moreover, as a representative advantage of using the direct spin detection collaborated with the polarization-variable laser, the technique unambiguously visualizes the light polarization dependence of the spin quantum axis in three-dimension. Laser-SARPES dramatically increases a capability of photoemission technique.
- Published
- 2018
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4. Bulk and Thin Film Synthesis of Compositionally Variant Entropy-stabilized Oxides.
- Author
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Sivakumar S, Zwier E, Meisenheimer PB, and Heron JT
- Subjects
- Entropy, Lasers statistics & numerical data, Oxides chemistry
- Abstract
Here, we present a procedure for the synthesis of bulk and thin film multicomponent (Mg0.25(1-x)CoxNi0.25(1-x)Cu0.25(1-x)Zn0.25(1-x))O (Co variant) and (Mg0.25(1-x)Co0.25(1-x)Ni0.25(1-x)CuxZn0.25(1-x))O (Cu variant) entropy-stabilized oxides. Phase pure and chemically homogeneous (Mg0.25(1-x)CoxNi0.25(1-x)Cu0.25(1-x)Zn0.25(1-x))O (x = 0.20, 0.27, 0.33) and (Mg0.25(1-x)Co0.25(1-x)Ni0.25(1-x)CuxZn0.25(1-x))O (x = 0.11, 0.27) ceramic pellets are synthesized and used in the deposition of ultra-high quality, phase pure, single crystalline thin films of the target stoichiometry. A detailed methodology for the deposition of smooth, chemically homogeneous, entropy-stabilized oxide thin films by pulsed laser deposition on (001)-oriented MgO substrates is described. The phase and crystallinity of bulk and thin film materials are confirmed using X-ray diffraction. Composition and chemical homogeneity are confirmed by X-ray photoelectron spectroscopy and energy dispersive X-ray spectroscopy. The surface topography of thin films is measured with scanning probe microscopy. The synthesis of high quality, single crystalline, entropy-stabilized oxide thin films enables the study of interface, size, strain, and disorder effects on the properties in this new class of highly disordered oxide materials.
- Published
- 2018
- Full Text
- View/download PDF
5. Custom Engineered Tissue Culture Molds from Laser-etched Masters.
- Author
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Kaiser NJ, Munarin F, and Coulombe KLK
- Subjects
- Drug Delivery Systems methods, Hydrogels metabolism, Lasers statistics & numerical data, Tissue Engineering methods
- Abstract
As the field of tissue engineering has continued to mature, there has been increased interest in a wide range of tissue parameters, including tissue shape. Manipulating tissue shape on the micrometer to centimeter scale can direct cell alignment, alter effective mechanical properties, and address limitations related to nutrient diffusion. In addition, the vessel in which a tissue is prepared can impart mechanical constraints on the tissue, resulting in stress fields that can further influence both the cell and matrix structure. Shaped tissues with highly reproducible dimensions also have utility for in vitro assays in which sample dimensions are critical, such as whole tissue mechanical analysis. This manuscript describes an alternative fabrication method utilizing negative master molds prepared from laser etched acrylic: these molds perform well with polydimethylsiloxane (PDMS), permit designs with dimensions on the centimeter scale and feature sizes smaller than 25 µm, and can be rapidly designed and fabricated at a low cost and with minimal expertise. The minimal time and cost requirements allow for laser etched molds to be rapidly iterated upon until an optimal design is determined, and to be easily adapted to suit any assay of interest, including those beyond the field of tissue engineering.
- Published
- 2018
- Full Text
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6. Assessing Community Health: An Innovative Tool for Measuring Height and Length.
- Author
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Bauman A, Ernst K, Hayden M, Roe DJ, Murray R, Agawo M, Munga S, Schmahl E, and Taren D
- Subjects
- Child, Child, Preschool, Female, Humans, Infant, Kenya, Male, Observer Variation, Pilot Projects, Reproducibility of Results, Anthropometry instrumentation, Lasers statistics & numerical data, Public Health methods
- Abstract
Anthropometric measurements, including height and length, are routinely needed for health research worldwide. Measurement boards are the current gold standard for obtaining the height and length of children. In community-based research, however, the size and weight of the measurement boards make them difficult and cumbersome to carry in the field. In addition, children and infants may express an unwillingness to be placed onto the measurement board. Electronic measuring tools commonly used in industry and contracting work are precise and portable. This study piloted a protocol to use an adapted laser measurement tool, the anthropometric measurement assist (AMA), to obtain height and recumbent length in children in Western Kenya. Intra- and inter-observer variability were determined and compared with measurement board measurements. Results of this initial pilot indicated that the AMA may be a viable alternative to measurement boards. The AMA can measure height/length accurately and reliably, is portable and is equivalent in price to measuring boards, making it a viable option for fieldwork in low-resourced countries.
- Published
- 2018
- Full Text
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7. High-Dimensional Fluorescence Cytometry.
- Author
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Ashhurst TM, Smith AL, and King NJC
- Subjects
- Animals, Antigens immunology, Antigens metabolism, Datasets as Topic, Flow Cytometry instrumentation, Fluorescence, Humans, Antibodies metabolism, Flow Cytometry methods, Fluorescent Dyes chemistry, Lasers statistics & numerical data, Single-Cell Analysis
- Abstract
The immune system consists of a complex network of cells, all expressing a wide range of surface and/or intracellular proteins. Using flow cytometry, these cells can be analyzed by labeling with fluorophore-conjugated antibodies. The recent expansion of fluorescence flow cytometry technology, in conjunction with the ever-expanding understanding of the complexity of the immune system, has led to the generation of larger high-dimensional fluorescence flow cytometry panels. However, as panel size and complexity increases, so too does the difficulty involved in constructing high-quality panels, in addition to the challenges of analyzing such high-dimensional datasets. As such, this unit seeks to review the key principles involved in building high-dimensional panels, as well as to guide users through the process of building and analyzing quality panels. Here, cytometer configuration, fluorophore brightness, spreading error, antigen density, choosing the best conjugates, titration, optimization, and data analysis will all be addressed. © 2017 by John Wiley & Sons, Inc., (Copyright © 2017 John Wiley & Sons, Inc.)
- Published
- 2017
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8. Continuous-wave Thulium Laser for Heating Cultured Cells to Investigate Cellular Thermal Effects.
- Author
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Miura Y, Pruessner J, Mertineit CL, Kern K, Muenter M, Moltmann M, Danicke V, and Brinkmann R
- Subjects
- Cells, Cultured cytology, Heating, Cells, Cultured metabolism, Laser Therapy methods, Lasers statistics & numerical data, Thulium chemistry
- Abstract
An original method to heat cultured cells using a 1.94 µm continuous-wave thulium laser for biological assessment is introduced here. Thulium laser radiation is strongly absorbed by water, and the cells at the bottom of the culture dish are heated through thermal diffusion. A laser fiber with a diameter of 365 µm is set about 12 cm above the culture dish, without any optics, such that the laser beam diameter is almost equivalent to the inner diameter of the culture dish (30 mm). By keeping a consistent amount of culture medium in each experiment, it is possible to irradiate the cells with a highly reproducible temperature increase. To calibrate the temperature increase and its distribution in one cell culture dish for each power setting, the temperature was measured during 10 s of irradiation at different positions and at the cellular level. The temperature distribution was represented using a mathematical graphics software program, and its pattern across the culture dish was in Gaussian form. After laser irradiation, different biological experiments could be performed to assess temperature-dependent cell responses. In this manuscript, viability staining (i.e., distinguishing live, apoptotic, and dead cells) is introduced to help determine the threshold temperatures for cell apoptosis and death after different points in time. The advantages of this method are the preciseness of the temperature and the time of heating, as well as its high efficiency in heating cells in a whole cell culture dish. Furthermore, it allows for study with a wide variety of temperatures and time durations, which can be well-controlled by a computerized operating system.
- Published
- 2017
- Full Text
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9. A new technique for treatment of tracheal stenosis.
- Author
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Batzella S, Lucantoni G, Galluccio G, Santini M, Caterino U, Reginelli A, and Fiorelli A
- Subjects
- Bronchoscopy instrumentation, Bronchoscopy methods, Endoscopy methods, Humans, Intubation, Intratracheal adverse effects, Lasers statistics & numerical data, Male, Middle Aged, Tracheal Stenosis etiology, Tracheostomy adverse effects, Treatment Outcome, Dilatation methods, Endoscopy instrumentation, Tracheal Stenosis surgery
- Abstract
We show the use of a new endoscopic drill for the management of web-like tracheal stenosis. Our device creates radial holes within stenosis that facilitate the use of scissors for cutting the scar tissue and the subsequent mechanical dilatation., (© The Author 2017. Published by MMCTS on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)
- Published
- 2017
- Full Text
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10. Endoscopic hand drill for management of tracheal stenosis.
- Author
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Sandro Batzella SB, Lucantoni G, Galluccio G, Santini M, Umberto Caterino UC, Reginelli A, and Alfonso Fiorelli AF
- Subjects
- Bronchoscopy methods, Endoscopy methods, Humans, Intubation, Intratracheal, Lasers statistics & numerical data, Male, Middle Aged, Tracheal Stenosis etiology, Bronchoscopy instrumentation, Dilatation methods, Endoscopy instrumentation, Tracheal Stenosis surgery
- Abstract
We propose the use of a new endoscopic drill for management of web-like tracheal stenosis. Our device allows creating radial holes within stenosis that facilitates the use of the scissors for cutting the scar and the subsequent mechanical dilatation., (© The Author 2016. Published by MMCTS on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)
- Published
- 2017
- Full Text
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11. Time-Resolved Macromolecular Crystallography at Modern X-Ray Sources.
- Author
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Schmidt M
- Subjects
- Crystallography, X-Ray instrumentation, Kinetics, Lasers statistics & numerical data, Protein Conformation, Proteins chemistry, Synchrotrons instrumentation, Thermodynamics, Time Factors, X-Ray Diffraction, Crystallography, X-Ray methods, Proteins ultrastructure
- Abstract
Time-resolved macromolecular crystallography unifies protein structure determination with chemical kinetics. With the advent of fourth generation X-ray sources the time-resolution can be on the order of 10-40 fs, which opens the ultrafast time scale to structure determination. Fundamental motions and transitions associated with chemical reactions in proteins can now be observed. Moreover, new experimental approaches at synchrotrons allow for the straightforward investigation of all kind of reactions in biological macromolecules. Here, recent developments in the field are reviewed.
- Published
- 2017
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12. Smooth and solid WS2 submicrospheres grown by a new laser fragmentation and reshaping process with enhanced tribological properties.
- Author
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Luo T, Wang P, Qiu Z, Yang S, Zeng H, and Cao B
- Subjects
- Materials Testing methods, Surface Properties, Biological Products chemical synthesis, Lasers statistics & numerical data, Microspheres, Tungsten Compounds chemical synthesis
- Abstract
Smooth and solid WS2 submicrospheres were prepared by a laser irradiation induced fragmentation and morphological reshaping process using bulk-slice WS2 particles as targets in solution. Such submicrospheres as additives in paraffin liquid show remarkably enhanced friction reduction and anti-wear properties in comparison with raw WS2 slices.
- Published
- 2016
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13. Effect of pulsed light on structure and immunoreactivity of gluten.
- Author
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Panozzo A, Manzocco L, Lippe G, and Nicoli MC
- Subjects
- Electrophoresis, Polyacrylamide Gel methods, Glutens chemistry, Lasers statistics & numerical data, Triticum chemistry
- Abstract
The effect of pulsed light (from 1.75 to 26.25Jcm(-2)) on selected properties of wheat gluten powder and aqueous suspension (absorbance, particle size and microstructure, free sulfhydryl content, protein fractions, protein electrophoretic mobility and immunoreactivity) was investigated. Gluten photoreactivity was strongly affected by hydration. While minor photo-induced structure modifications were observed in gluten powder, pulsed light induced the development of browning and promoted partial depolymerisation of hydrated gluten proteins by disulphide exchange. These changes were associated with a significant decrease in immunoreactivity, suggesting that pulsed light could be exploited to efficiently modify structure and thus functionality of gluten., (Copyright © 2015 Elsevier Ltd. All rights reserved.)
- Published
- 2016
- Full Text
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14. Comparison of intra-ocular pressure changes with liquid or flat applanation interfaces in a femtosecond laser platform.
- Author
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Williams GP, Ang HP, George BL, Liu YC, Peh G, Izquierdo L, Tan DT, and Mehta JS
- Subjects
- Aged, Animals, Humans, Swine, Cataract therapy, Intraocular Pressure physiology, Lasers statistics & numerical data, Tonometry, Ocular instrumentation
- Abstract
Cataract surgery is the most common surgical procedure and femtosecond laser assisted cataract surgery (FLACS) has gained increased popularity. FLACS requires the application of a suction device to stabilize the laser head and focus the laser beam accurately. This may cause a significant escalation in intra-ocular pressure (IOP), which poses potential risks for patients undergoing cataract surgery. In this study we aimed to assess the effect of the Ziemer LDV Z8 femtosecond cataract machine on IOP. We demonstrated through a porcine model that IOP was significantly higher with a flat interface but could be abrogated by reducing surgical compression and vacuum. Pressure was lower with a liquid interface, and further altering angulation of the laser arm could reduce the IOP to 36 mmHg. A pilot series in patients showed comparable pressure rises with the porcine model (30 mmHg). These strategies may improve the safety profile in patients vulnerable to high pressure when employing FLACS with the Ziemer LDV Z8.
- Published
- 2015
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15. A laser ablation ICP-MS based method for multiplexed immunoblot analysis: applications to manganese-dependent protein dynamics of photosystem II in barley (Hordeum vulgare L.).
- Author
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de Bang TC, Petersen J, Pedas PR, Rogowska-Wrzesinska A, Jensen ON, Schjoerring JK, Jensen PE, Thelen JJ, and Husted S
- Subjects
- Immunoblotting, Spectrometry, Mass, Electrospray Ionization, Hordeum metabolism, Lasers statistics & numerical data, Manganese metabolism, Photosystem II Protein Complex metabolism
- Abstract
Manganese (Mn) constitutes an essential co-factor in the oxygen-evolving complex of photosystem II (PSII). Consequently, Mn deficiency reduces photosynthetic efficiency and leads to changes in PSII composition. In order to study these changes, multiplexed protein assays are advantageous. Here, we developed a multiplexed antibody-based assay and analysed selected PSII subunits in barley (Hordeum vulgare L.). A selection of antibodies were labelled with specific lanthanides and immunoreacted with thylakoids exposed to Mn deficiency after western blotting. Subsequently, western blot membranes were analysed by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), which allowed selective and relative quantitative analysis via the different lanthanides. The method was evaluated against established liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) methods, based on data-dependent acquisition (DDA) and selected reaction monitoring (SRM). Manganese deficiency resulted in a general decrease in PSII protein abundances, an effect that was shown to be reversible upon Mn re-supplementation. Specifically, the extrinsic proteins PsbP and PsbQ showed Mn-dependent changes in abundances. Similar trends in the response to Mn deficiency at the protein level were observed when comparing DDA, SRM and LA-ICP-MS results. A biologically important exception to this trend was the loss of PsbO in the SRM analysis, which highlights the necessity of validating protein changes by more than one technique. The developed method enables a higher number of proteins to be multiplexed in comparison to existing immunoassays. Furthermore, multiplexed protein analysis by LA-ICP-MS provides an analytical platform with high throughput appropriate for screening large collections of plants., (© 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.)
- Published
- 2015
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16. Batch crystallization of rhodopsin for structural dynamics using an X-ray free-electron laser.
- Author
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Wu W, Nogly P, Rheinberger J, Kick LM, Gati C, Nelson G, Deupi X, Standfuss J, Schertler G, and Panneels V
- Subjects
- Animals, Cattle, Crystallization, Lasers statistics & numerical data, Rhodopsin chemistry, X-Ray Diffraction methods
- Abstract
Rhodopsin is a membrane protein from the G protein-coupled receptor family. Together with its ligand retinal, it forms the visual pigment responsible for night vision. In order to perform ultrafast dynamics studies, a time-resolved serial femtosecond crystallography method is required owing to the nonreversible activation of rhodopsin. In such an approach, microcrystals in suspension are delivered into the X-ray pulses of an X-ray free-electron laser (XFEL) after a precise photoactivation delay. Here, a millilitre batch production of high-density microcrystals was developed by four methodical conversion steps starting from known vapour-diffusion crystallization protocols: (i) screening the low-salt crystallization conditions preferred for serial crystallography by vapour diffusion, (ii) optimization of batch crystallization, (iii) testing the crystal size and quality using second-harmonic generation (SHG) imaging and X-ray powder diffraction and (iv) production of millilitres of rhodopsin crystal suspension in batches for serial crystallography tests; these crystals diffracted at an XFEL at the Linac Coherent Light Source using a liquid-jet setup.
- Published
- 2015
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17. Handheld lasers allow efficient detection of fluorescent marked organisms in the field.
- Author
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Rice KB, Fleischer SJ, De Moraes CM, Mescher MC, Tooker JF, and Gish M
- Subjects
- Animals, Humans, Population Dynamics, Animal Identification Systems methods, Fluorescent Dyes chemistry, Heteroptera chemistry, Lasers statistics & numerical data
- Abstract
Marking organisms with fluorescent dyes and powders is a common technique used in ecological field studies that monitor movement of organisms to examine life history traits, behaviors, and population dynamics. External fluorescent marking is relatively inexpensive and can be readily employed to quickly mark large numbers of individuals; however, the ability to detect marked organisms in the field at night has been hampered by the limited detection distances provided by portable fluorescent ultraviolet lamps. In recent years, significant advances in LED lamp and laser technology have led to development of powerful, low-cost ultraviolet light sources. In this study, we evaluate the potential of these new technologies to improve detection of fluorescent-marked organisms in the field and to create new possibilities for tracking marked organisms in visually challenging environments such as tree canopies and aquatic habitats. Using handheld lasers, we document a method that provides a fivefold increase in detection distance over previously available technologies. This method allows easy scouting of tree canopies (from the ground), as well as shallow aquatic systems. This novel detection method for fluorescent-marked organisms thus promises to significantly enhance the use of fluorescent marking as a non-destructive technique for tracking organisms in natural environments, facilitating field studies that aim to document otherwise inaccessible aspects of the movement, behavior, and population dynamics of study organisms, including species with significant economic impacts or relevance for ecology and human health.
- Published
- 2015
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18. The return of the jedi: comparison of the outcomes of endolaser dacryocystorhinostomy and endonasal dacryocystorhinostomy.
- Author
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Zengin MÖ and Eren E
- Subjects
- Adult, Aged, Endoscopy, Female, Follow-Up Studies, Humans, Male, Middle Aged, Retrospective Studies, Treatment Outcome, Dacryocystorhinostomy methods, Lacrimal Apparatus Diseases therapy, Lacrimal Duct Obstruction therapy, Lasers statistics & numerical data, Nose surgery
- Abstract
Background: External dacryocystorhinostomy (DCR) is considered to be the gold standard treatment of primary acquired nasolacrimal duct obstruction. A better understanding of the endoscopic anatomy of the lacrimal sac has increased the success rate of endonasal DCR. Laser DCR has become popular in recent years and has a success rate comparable with those of other endonasal techniques. The aim of this study was to compare the surgical results of endonasal DCR (EDCR) and endonasal laser DCR (ELDCR)., Methods: Fifty-four patients treated with ELDCR and 42 patients treated with EDCR for nasolacrimal duct obstruction from 2009 to 2012 with at least 1.5 years of follow-up were retrospectively enrolled in this comparative study. Lack of patient complaints and irrigation testing were used as subjective and objective assessment tools, respectively., Results: Both groups were similar in terms of age and sex. ELDCR had a success rate of 85.2%, and EDCR had a success rate of 92.9%. The difference between the 2 procedures was not statistically significant. ELDCR had a significantly shorter operative time than did EDCR (16.9 vs 24.4 minutes, respectively; p < 0.001)., Conclusion: Endonasal procedures have the advantage of no scar formation and do not disturb the pumping mechanism of the lacrimal sac. Their success rates are comparable with those of external DCR. Surgery is quicker, and with use of a laser, even less time is spent in the operating room. In selected cases, ELDCR can be a good alternative method with a high success rate., (© 2014 ARS-AAOA, LLC.)
- Published
- 2014
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19. Lasers as an approach for promoting drug delivery via skin.
- Author
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Lin CH, Aljuffali IA, and Fang JY
- Subjects
- Administration, Cutaneous, Animals, Biological Availability, Humans, Skin drug effects, Drug Delivery Systems methods, Lasers statistics & numerical data, Skin metabolism, Skin Absorption physiology
- Abstract
Introduction: Using lasers can be an effective drug permeation-enhancement approach for facilitating drug delivery into or across the skin. The controlled disruption and ablation of the stratum corneum (SC), the predominant barrier for drug delivery, is achieved by the use of lasers. The possible mechanisms of laser-assisted drug permeation are the direct ablation of the skin barrier, optical breakdown by a photomechanical wave and a photothermal effect. It has been demonstrated that ablative approaches for enhancing drug transport provide some advantages, including increased bioavailability, fast treatment time, quick recovery of SC integrity and the fact that skin surface contact is not needed. In recent years, the concept of using laser techniques to treat the skin has attracted increasing attention., Areas Covered: This review describes recent developments in using nonablative and ablative lasers for drug absorption enhancement. This review systematically introduces the concepts and enhancement mechanisms of lasers, highlighting the potential of this technique for greatly increasing drug absorption via the skin. Lasers with different wavelengths and types are employed to increase drug permeation. These include the ruby laser, the erbium:yttrium-gallium-garnet laser, the neodymium-doped yttrium-aluminum-garnet laser and the CO2 laser. Fractional modality is a novel concept for promoting topical/transdermal drug delivery. The laser is useful in enhancing the permeation of a wide variety of permeants, such as small-molecule drugs, macromolecules and nanoparticles., Expert Opinion: This potential use of the laser affords a new treatment for topical/transdermal application with significant efficacy. Further studies using a large group of humans or patients are needed to confirm and clarify the findings in animal studies. Although the laser fluence or output energy used for enhancing drug absorption is much lower than for treatment of skin disorders and rejuvenation, the safety of using lasers is still an issue. Caution should be used in optimizing the feasible conditions of the lasers in balancing the effectiveness of permeation enhancement and skin damage.
- Published
- 2014
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20. Protective mechanisms of adenosine 5'-monophosphate in platelet activation and thrombus formation.
- Author
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Fuentes E, Badimon L, Caballero J, Padró T, Vilahur G, Alarcón M, Pérez P, and Palomo I
- Subjects
- Adenosine A2 Receptor Agonists pharmacology, Adenosine Monophosphate analogs & derivatives, Animals, Blood Platelets drug effects, CD40 Ligand metabolism, Cells, Cultured, Crotalid Venoms metabolism, Cyclic Nucleotide Phosphodiesterases, Type 3 metabolism, Disease Models, Animal, Humans, Lasers statistics & numerical data, Lectins, C-Type metabolism, Mesenteric Veins drug effects, Mesenteric Veins radiation effects, Mice, Molecular Targeted Therapy, P-Selectin genetics, P-Selectin metabolism, Peptide Fragments metabolism, Photochemical Processes, Platelet Activation drug effects, Platelet Glycoprotein GPIIb-IIIa Complex genetics, Platelet Glycoprotein GPIIb-IIIa Complex metabolism, Rose Bengal administration & dosage, Stereoisomerism, Thrombosis chemically induced, Thrombosis drug therapy, Triazines pharmacology, Triazoles pharmacology, Adenosine Monophosphate metabolism, Blood Platelets physiology, Mesenteric Veins physiology, Receptor, Adenosine A2A metabolism, Thrombosis blood
- Abstract
Platelet activation is relevant to a variety of acute thrombotic events. We sought to examine adenosine 5'-monophosphate (AMP) mechanisms of action in preventing platelet activation, thrombus formation and platelet-related inflammatory response. We assessed the effect of AMP on 1) P-selectin expression and GPIIb/IIIa activation by flow cytometry; 2) Platelet aggregation and ATP secretion induced by ADP, collagen, TRAP-6, convulxin and thrombin; 3) Platelet rolling and firm adhesion, and platelet-leukocyte interactions under flow-controlled conditions; and, 4) Platelet cAMP levels, sP-selectin, sCD40L, IL-1β, TGF-β1 and CCL5 release, PDE3A activity and PKA phosphorylation. The effect of AMP on in vivo thrombus formation was also evaluated in a murine model. The AMP docking with respect to A2 adenosine receptor was determined by homology. AMP concentration-dependently (0.1 to 3 mmol/l) inhibited P-selectin expression and GPIIb/IIIa activation, platelet secretion and aggregation induced by ADP, collagen, TRAP-6 and convulxin, and diminished platelet rolling and firm adhesion. Furthermore, AMP induced a marked increase in the rolling speed of leukocytes retained on the platelet surface. At these concentrations AMP significantly decreased inflammatory mediator from platelet, increased intraplatelet cAMP levels and inhibited PDE3A activity. Interestingly, SQ22536, ZM241385 and SCH58261 attenuated the antiplatelet effect of AMP. Docking experiments revealed that AMP had the same orientation that adenosine inside the A2 adenosine receptor binding pocket. These in vitro antithrombotic properties were further supported in an in vivo model of thrombosis. Considering the successful use of combined antiplatelet therapy, AMP may be further developed as a novel antiplatelet agent.
- Published
- 2014
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21. Toll-like receptor 2-mediated alternative activation of microglia is protective after spinal cord injury.
- Author
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Stirling DP, Cummins K, Mishra M, Teo W, Yong VW, and Stys P
- Subjects
- Animals, Axons drug effects, Axons ultrastructure, Bacterial Proteins, Disease Models, Animal, Green Fluorescent Proteins, Lasers statistics & numerical data, Luminescent Proteins, Mice, Mice, Inbred C57BL, Mice, Knockout, Microglia drug effects, Microglia ultrastructure, Microscopy, Confocal, Myelin Sheath drug effects, Myelin Sheath ultrastructure, Spinal Cord Injuries etiology, Spinal Cord Injuries pathology, Toll-Like Receptor 2 agonists, Axons pathology, Lipopeptides pharmacology, Microglia pathology, Myelin Sheath pathology, Neuroprotective Agents pharmacology, Spinal Cord Injuries metabolism, Toll-Like Receptor 2 metabolism
- Abstract
Improving neurological outcome after spinal cord injury is a major clinical challenge because axons, once severed, do not regenerate but 'dieback' from the lesion site. Although microglia, the immunocompetent cells of the brain and spinal cord respond rapidly to spinal cord injury, their role in subsequent injury or repair remains unclear. To assess the role of microglia in spinal cord white matter injury we used time-lapse two-photon and spectral confocal imaging of green fluorescent protein-labelled microglia, yellow fluorescent protein-labelled axons, and Nile Red-labelled myelin of living murine spinal cord and revealed dynamic changes in white matter elements after laser-induced spinal cord injury in real time. Importantly, our model of acute axonal injury closely mimics the axonopathy described in well-characterized clinically relevant models of spinal cord injury including contusive-, compressive- and transection-based models. Time-lapse recordings revealed that microglia were associated with some acute pathophysiological changes in axons and myelin acutely after laser-induced spinal cord injury. These pathophysiological changes included myelin and axonal spheroid formation, spectral shifts in Nile Red emission spectra in axonal endbulbs detected with spectral microscopy, and 'bystander' degeneration of axons that survived the initial injury, but then succumbed to secondary degeneration. Surprisingly, modulation of microglial-mediated release of neurotoxic molecules failed to protect axons and myelin. In contrast, sterile stimulation of microglia with the specific toll-like receptor 2 agonist Pam2CSK4 robustly increased the microglial response to ablation, reduced secondary degeneration of central myelinated fibres, and induced an alternative (mixed M1:M2) microglial activation profile. Conversely, Tlr2 knock out: Thy1 yellow fluorescent protein double transgenic mice experienced greater axonal dieback than littermate controls. Thus, promoting an alternative microglial response through Pam2CSK4 treatment is neuroprotective acutely following laser-induced spinal cord injury. Therefore, anti-inflammatory treatments that target microglial activation may be counterintuitive after spinal cord injury.
- Published
- 2014
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22. Crystallography: Sources of inspiration.
- Author
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McSweeney S and Fromme P
- Subjects
- Crystallography, X-Ray trends, Electrons, Proteins chemistry, Proteins radiation effects, Crystallography, X-Ray instrumentation, Lasers statistics & numerical data, Synchrotrons statistics & numerical data
- Published
- 2014
- Full Text
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23. MALDI mass spectrometry imaging in microscope mode with infrared lasers: bypassing the diffraction limits.
- Author
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Soltwisch J, Göritz G, Jungmann JH, Kiss A, Smith DF, Ellis SR, and Heeren RM
- Subjects
- Animals, Liver chemistry, Liver cytology, Osmeriformes, Random Allocation, Infrared Rays, Lasers statistics & numerical data, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization methods
- Abstract
This letter demonstrates the use of infrared matrix-assisted laser desorption/ionization coupled with microscope mode mass spectrometry imaging. It is aimed to explore the use of intrinsic water in tissue as a matrix for imaging at spatial resolutions below the diffraction limit of the employed IR optics. Stigmatic ion optics with a magnification factor of ~70 were used to project the spatial distribution of produced ions onto a detector while separating ions with different mass-to-charge ratios using a time-of-flight mass spectrometer. A pixelated detector was used to simultaneously record arrival time and impact position. A previously described dried-droplet sample system of 2,5-dihydroxybenzoic acid (DHB) and 5 peptides covered by a copper grid for defined surface structure was used to benchmark the light- and ion-optical setup for spatial resolution and mass spectrometric performance. A spatial resolving power of 9.8 μm, well below the optical limit of diffraction (14 μm for the given setup), was established. After, frozen cryo-sections from a biological model system were measured by exploiting the endogenous water content as a matrix. Principal component analysis enabled a clear distinction between distinct tissue regions identified by both light microscopy and MS imaging.
- Published
- 2014
- Full Text
- View/download PDF
24. Recent developments in retinal lasers and delivery systems.
- Author
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Yadav NK, Jayadev C, Rajendran A, and Nagpal M
- Subjects
- Equipment Design, Humans, Laser Coagulation instrumentation, Lasers statistics & numerical data, Retina surgery, Retinal Diseases surgery
- Abstract
Photocoagulation is the standard of care for several ocular disorders and in particular retinal conditions. Technology has offered us newer lasing mediums, wavelengths and delivery systems. Pattern scan laser in proliferative diabetic retinopathy and diabetic macular edema allows laser treatment that is less time consuming and less painful. Now, it is possible to deliver a subthreshold micropulse laser that is above the threshold of biochemical effect but below the threshold of a visible, destructive lesion thereby preventing collateral damage. The advent of solid-state diode yellow laser allows us to treat closer to the fovea, is more effective for vascular structures and offers a more uniform effect in patients with light or irregular fundus pigmentation. Newer retinal photocoagulation options along with their advantages is discussed in this review.
- Published
- 2014
- Full Text
- View/download PDF
25. Usage of GreenLight HPS 180-W laser vaporisation for treatment of benign prostatic hyperplasia.
- Author
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Jovanović M, Džamić Z, Aćimović M, Kajmaković B, and Pejčić T
- Subjects
- Aged, Comparative Effectiveness Research, Humans, Lasers statistics & numerical data, Length of Stay, Male, Middle Aged, Prospective Studies, Prostate pathology, Prostatic Hyperplasia complications, Prostatic Hyperplasia diagnosis, Treatment Outcome, Laser Therapy adverse effects, Laser Therapy instrumentation, Laser Therapy methods, Lower Urinary Tract Symptoms etiology, Lower Urinary Tract Symptoms psychology, Lower Urinary Tract Symptoms therapy, Postoperative Complications surgery, Prostatic Hyperplasia therapy, Quality of Life, Transurethral Resection of Prostate adverse effects, Transurethral Resection of Prostate methods, Urinary Bladder Neck Obstruction etiology, Urinary Bladder Neck Obstruction surgery
- Abstract
Introduction: Laser therapy has gained increasing acceptance as a relatively less invasive treatment for lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH). From the early procedure of interstitial laser coagulation through to the use of holmium laser enucleation of the prostate, there has been an expanding body of evidence on the efficacy of such procedures. One of the newer lasers is the Green Light HPS 180 W laser. Studies with this GreenLight laser (GLL) (American Medical Systems, Inc, Minnetonka, MN, USA) showing results as good as those of transurethral resection of the prostate (TURP). In this paper, the efficacy of the new GLL 180-W versus the gold standard TURP in patients with LUTS due to BPH was tested in a prospective clinical trial., Objective: To compare results of Green light laser (GLL) evaporisation of the prostatae and transurethral resection of the prostate (TURP) for treatment of BPH. MATERIJALS AND METHODS: A total of 62 patients with BPH were randomly assigned to two equal groups: TURP or GLL., Results: Both groups were compared regarding all relevant preoperative, operative, and postoperative parameters. Functional results in terms of improvement of International Prostate Symptom Score (IPSS), maximum flow rate (Qmax), and postvoid residual (PVR) urine were assessed at 1, 3, 6 and 12 mo. A total of 62 patients completed 12 mo of follow-up in the TURP and GLL groups, respectively. Baseline characteristics were comparable. Mean operative time was significantly shorter for TURP. Compared to preoperative values, there was significant reduction in hemoglobin levels at the end of TURP only. A significant difference in favor of GLL was achieved regarding the duration of catheterization and hospital stay. In the GLL, no major intraoperative complications were recorded and none of the patients required blood transfusion. Among TURP patients, 6 required transfusion, 1 developed TUR syndrome, and capsule perforation was observed in 5 patients. There was dramatic improvement in Qmax, IPSS, and GLL compared with preoperative values and the degree of improvement was comparable in both groups at all time points of follow-up. Four TURP patients and one GLL patients developed bladder neck contracture treated by bladder neck incision; none in either group experienced urethral stricture or urinary incontinence., Conclusions: Compared to transurethral resection of the prostate, GreenLight HPS 180-W laser photoselective vaporization of the prostate is safe and effective in the treatment of patients suffering from lower urinary tract symptoms due to benign prostatic hyperplasia.
- Published
- 2014
26. Laser scanning as a useful tool in implant retrieval analysis: a demonstration using rotating platform and fixed bearing tibial inserts.
- Author
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Stoner KE, Nassif NA, Wright TM, and Padgett DE
- Subjects
- Aged, Aged, 80 and over, Female, Hip Joint surgery, Humans, Male, Middle Aged, Polyethylene, Prosthesis Design, Prosthesis Failure, Stress, Mechanical, Arthroplasty, Replacement, Knee instrumentation, Device Removal, Equipment Failure Analysis methods, Imaging, Three-Dimensional methods, Knee Prosthesis, Lasers statistics & numerical data, Tibia surgery
- Abstract
Objective methods for analyzing arthroplasty retrieval implants are needed. To address this, we used a readily available laser scanner to analyze damage deviations between cohorts of rotating platform and fixed bearing inserts previously analyzed using traditional, subjective retrieval analysis methods. We asked the following research questions: 1) Do articular surface deviations measured by the scanner correlate with the subjective damage scores? 2) Do articular surface deviations differ between inserts due to design differences? Correlations between deviations and damage scores were present in RP but not FB inserts. Seven different deviation patterns were present between the RP and FB inserts and were a function of design. In conclusion laser scanning was found to be a useful objective tool for analyzing arthroplasty retrievals., (© 2013 Elsevier Inc. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
27. Laser-printing of toner-based 96-microzone plates for immunoassays.
- Author
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Oliveira KA, Rodrigues de Oliveira C, Antonelli da Silveira L, and Coltro WK
- Subjects
- Animals, Cells, Cultured, Mice, Cell Culture Techniques methods, Enzyme-Linked Immunosorbent Assay methods, Lasers statistics & numerical data, Printing methods
- Abstract
This work describes the quick and simple fabrication of toner-based 96-microzone plates by a direct-printing technology. The printer deposits a toner layer (ca. 5 μm thick) on the polyester surface which acts as a hydrophobic barrier to confine small volumes of sample on test zones (wells). A 96-microzone toner plate was explored to demonstrate its capability of performing enzyme-linked immunosorbent assay (ELISA). The detection of anti-immunoglobulin G (anti-IgG) and immunoglobulin M (IgM) antibodies has been successfully achieved in cell culture and serum samples, respectively. The use of a conventional microplate reader has allowed obtaining a limit of detection of 13 fmol of mouse IgG per zone on printed microplates. The IgM antibody has been detected in a serum sample collected from a patient infected with dengue virus. The detection of a primary infection has been provided by a microplate reader and also by a cell phone camera. Besides the bioanalytical feasibility, toner-based zones have shown good repeatability for inter-zone and intra-plate comparisons. The relative standard deviation (RSD) values for inter-zone (n = 12) and intra-plate (n = 3) comparisons were lower than 6% and 11%, respectively. Furthermore, it was found that the lifetime of each printed microplate depends on the storage temperature. The shelf life for devices stored at 10 °C has been estimated to be ca. four weeks.
- Published
- 2013
- Full Text
- View/download PDF
28. In situ imaging of honeybee (Apis mellifera) venom components from aqueous and aluminum hydroxide-adsorbed venom immunotherapy preparations.
- Author
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Seppälä U, Francese S, Turillazzi S, Moneti G, Clench M, and Barber D
- Subjects
- Allergens administration & dosage, Allergens adverse effects, Allergens pharmacokinetics, Aluminum Hydroxide administration & dosage, Aluminum Hydroxide chemistry, Animals, Antigens, Plant administration & dosage, Antigens, Plant adverse effects, Bee Venoms adverse effects, Bee Venoms metabolism, Bees, Biogenic Amines metabolism, Cryoultramicrotomy, Humans, Hyaluronoglucosaminidase administration & dosage, Hyaluronoglucosaminidase adverse effects, Hyaluronoglucosaminidase pharmacokinetics, Hypersensitivity diagnosis, Insect Proteins administration & dosage, Insect Proteins adverse effects, Insect Proteins pharmacokinetics, Lasers statistics & numerical data, Melitten adverse effects, Melitten immunology, Peptides metabolism, Phospholipases A administration & dosage, Phospholipases A adverse effects, Phospholipases A pharmacokinetics, Rats, Rats, Wistar, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization instrumentation, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization methods, Water administration & dosage, Water chemistry, Bee Venoms immunology, Desensitization, Immunologic, Hypersensitivity drug therapy, Hypersensitivity immunology
- Abstract
Background: Treatment with aqueous and aluminum hydroxide (Al[OH](3))-adsorbed purified honeybee (Apis mellifera) venom (HBV) preparations can reduce the incidence of side effects associated with venom immunotherapy., Objective: The aim of the present study was to assess these purified HBV immunotherapy preparations in situ., Methods: Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) was used to visualize the distribution of HBV components. The preparations were administered on the back legs of naive Wistar rats. The rats were killed, and cryosectioned tissue sections were subjected to hematoxylin and eosin staining and MALDI-MSI analyses., Results: Low-density maps of tissue distribution of HBV peptides, such as secapin, mast cell degranulating peptide, and melittin (Api m 4) were detected in the tissue after administration of HBV immunotherapy preparations. In addition, release of biogenic amines, cytokines, and leukotrienes was observed, and the distribution of HBV allergens, such as Api m 1 and Api m 2, was shown. At the 24-hour time point, the major HBV allergen Api m 1 was still detected at the site of Al(OH)(3)-adsorbed HVB injection, whereas in the case of aqueous HBV preparation, all the allergens, as well as most of the biogenic amines, were cleared at the 24-hour time point., Conclusion: The present study shows that the majority of low-molecular-weight HBV components are rapidly removed from the site of venom immunotherapy administration. Furthermore, Al(OH)(3)-adsorbed HBV preparation demonstrated a depot effect, prolonging the availability of bee venom allergens at the site of administration., (Copyright © 2011 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.)
- Published
- 2012
- Full Text
- View/download PDF
29. Controversial research: Good science bad science.
- Author
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Brumfiel G
- Subjects
- Bioterrorism prevention & control, Female, Genetic Testing ethics, Genetic Testing trends, Global Warming prevention & control, Humans, Influenza A Virus, H5N1 Subtype genetics, Influenza A Virus, H5N1 Subtype pathogenicity, Lasers statistics & numerical data, Lie Detection, Magnetic Resonance Imaging, Neuroimaging, Nuclear Medicine, Nuclear Weapons, Pregnancy, Prenatal Diagnosis ethics, Prenatal Diagnosis trends, Radioisotopes chemistry, Radioisotopes isolation & purification, Risk Assessment, Security Measures, Uranium chemistry, Uranium isolation & purification, Ethics, Research, Research standards
- Published
- 2012
- Full Text
- View/download PDF
30. What is the role of partial middle turbinectomy in endocanalicular laser-assisted endonasal dacryocystorhinostomy?
- Author
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Basmak H, Cakli H, Sahin A, Gursoy H, Ozer A, and Colak E
- Subjects
- Adult, Aged, Female, Follow-Up Studies, Humans, Lacrimal Apparatus pathology, Lacrimal Apparatus surgery, Lacrimal Apparatus Diseases diagnosis, Lacrimal Apparatus Diseases pathology, Lacrimal Apparatus Diseases physiopathology, Lasers statistics & numerical data, Male, Middle Aged, Nasolacrimal Duct pathology, Prospective Studies, Recovery of Function, Turbinates pathology, Dacryocystorhinostomy, Lacrimal Apparatus metabolism, Lacrimal Apparatus Diseases surgery, Nasolacrimal Duct surgery, Turbinates surgery
- Abstract
Background: This study was designed to compare outcomes of endocanalicular laser-assisted endonasal dacryocystorhinostomy (DCR) with and without partial anterior middle turbinectomy., Methods: A prospective randomized comparative study was conducted on 91 subjects with primary acquired nasolacrimal duct obstruction, undergoing endocanalicular (ECL) procedures. Group 1 was composed of 44 (7 bilateral) patients undergoing ECL diode laser-assisted endonasal DCR without partial anterior middle turbinectomy and group 2 was composed of 47 (7 bilateral) patients undergoing partial anterior middle turbinectomy and ECL diode laser-assisted endonasal DCR. Follow-up period was 11.0 (6.0-14.5 months) months for group 1 and 9.2 (5.0-14.2 months) months for group 2. Functional success was defined as absence of epiphora and anatomic success was defined as ability to irrigate the lacrimal system. Anatomic and functional success at the 1st week, 3rd month, and final postoperative examinations of two groups were compared using chi-square tests., Results: Final anatomic successes were 39/51 (76%) cases for group 1 and 51/54 (94%) cases for group 2. Final functional successes were 36/51 (%71) patients in group 1 and 48/54 (88%) patients in group 2. Group 2 had higher success at the final examination and the difference was statistically significant., Conclusion: We recommend partial anterior middle turbinectomy in all laser ECL laser-assisted endonasal DCR, but further studies with larger sample sizes are needed to strengthen our hypothesis.
- Published
- 2011
- Full Text
- View/download PDF
31. Perceived size and perceived direction: the interplay of the two descriptors of visual space.
- Author
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Sikl R and Simecek M
- Subjects
- Adult, Female, Humans, Lasers statistics & numerical data, Male, Orientation, Psychological Tests, Young Adult, Judgment physiology, Size Perception physiology, Space Perception physiology, Visual Perception physiology
- Abstract
The stimulus in the outdoor psychophysical experiment was formed by two rods placed on the ground plane over a range of possible distances and orientations. Observers estimated its size and direction by positioning the third rod in the neighbouring space to form an evenly spaced collinear triple of rods. The data revealed interesting similarities between the profiles of the deviations in both judgments: for size judgments, the variability of the responses was least when the targets were at a frontal orientation and gradually increased as the orientation approached the medial plane. For direction judgments, on the other hand, the variability of the responses was least when the stimuli were aligned with the observer's line of sight and gradually increased as the orientation approached the frontoparallel plane. The finding of inverse relationship between the precision of size and direction judgments is interpreted as a consequence of the unequal precision in localisation between the frontal and in-depth dimensions of visual space. The question of the best parameterisation of the observers' responses is discussed.
- Published
- 2011
- Full Text
- View/download PDF
32. Low-threshold electrically pumped random lasers.
- Author
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Zhu H, Shan CX, Zhang JY, Zhang ZZ, Li BH, Zhao DX, Yao B, Shen DZ, Fan XW, Tang ZK, Hou X, and Choy KL
- Subjects
- Electricity, Crystallins chemistry, Lasers statistics & numerical data, Semiconductors instrumentation, Zinc Oxide chemistry
- Published
- 2010
- Full Text
- View/download PDF
33. 2020 visions.
- Subjects
- Age Distribution, Agriculture methods, Agriculture trends, Animals, Astronomy trends, Bioengineering methods, Bioengineering trends, Chemistry trends, Conservation of Energy Resources economics, Conservation of Energy Resources trends, Demography, Drug Industry trends, Ecology trends, Green Chemistry Technology trends, Hominidae, Humans, International Cooperation, Internet trends, Lasers statistics & numerical data, Mental Disorders genetics, Mental Disorders therapy, Metabolomics trends, Metagenome, National Institutes of Health (U.S.) organization & administration, National Institutes of Health (U.S.) trends, Paleontology trends, Precision Medicine ethics, Precision Medicine trends, Research education, Search Engine methods, Search Engine trends, Soil standards, United States, Universities standards, Universities trends, Research trends
- Published
- 2010
- Full Text
- View/download PDF
34. Facile analysis of metabolites by capillary electrophoresis coupled to matrix-assisted laser desorption/ionization mass spectrometry using target plates with polysilazane nanocoating and grooves.
- Author
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Amantonico A, Urban PL, and Zenobi R
- Subjects
- Air Ionization, Clinical Laboratory Techniques, Electrophoresis, Capillary methods, Lasers statistics & numerical data, Spectrophotometry, Ultraviolet methods, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization methods
- Abstract
We present an inexpensive method and apparatus for the deposition of analytes separated by capillary electrophoresis (CE) onto a custom-designed matrix-assisted laser desorption/ionization (MALDI) target plate. This dedicated CE-MALDI plate is coated with an omniphobic polysilazane nanocoating and has an array of parallel grooves acting as recipients of the separation effluent. The 3-D pattern in the top layer of the coated plate greatly improves loading of the matrix solution prior to separation and facilitates deposition of the separated species. We demonstrate application of this straightforward protocol to the analysis of metabolites from the central metabolic pathway in a complex biological sample spiked with small molecule standards.
- Published
- 2009
- Full Text
- View/download PDF
35. [Analysis and experimental verification of sensitivity and SNR of laser warning receiver].
- Author
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Zhang JL, Wang M, Tian EM, Li X, Wang ZB, and Zhang Y
- Subjects
- Electronic Data Processing, Image Enhancement, Noise, Sensitivity and Specificity, Signal Detection, Psychological, Algorithms, Image Processing, Computer-Assisted methods, Lasers statistics & numerical data, Monte Carlo Method
- Abstract
In order to countermeasure increasingly serious threat from hostile laser in modern war, it is urgent to do research on laser warning technology and system, and the sensitivity and signal to noise ratio (SNR) are two important performance parameters in laser warning system. In the present paper, based on the signal statistical detection theory, a method for calculation of the sensitivity and SNR in coherent detection laser warning receiver (LWR) has been proposed. Firstly, the probabilities of the laser signal and receiver noise were analyzed. Secondly, based on the threshold detection theory and Neyman-Pearson criteria, the signal current equation was established by introducing detection probability factor and false alarm rate factor, then, the mathematical expressions of sensitivity and SNR were deduced. Finally, by using method, the sensitivity and SNR of the sinusoidal grating laser warning receiver developed by our group were analyzed, and the theoretic calculation and experimental results indicate that the SNR analysis method is feasible, and can be used in performance analysis of LWR.
- Published
- 2009
36. A survey of investigations used for the management of glaucoma in hospital service in the United Kingdom.
- Author
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Gordon-Bennett PS, Ioannidis AS, Papageorgiou K, and Andreou PS
- Subjects
- Glaucoma therapy, Health Surveys, Hospitalization, Humans, Lasers statistics & numerical data, Photography statistics & numerical data, Practice Guidelines as Topic, Surveys and Questionnaires, Tomography, Optical, Tonometry, Ocular statistics & numerical data, United Kingdom, Visual Field Tests statistics & numerical data, Diagnostic Techniques, Ophthalmological statistics & numerical data, Glaucoma diagnosis, Ophthalmology trends, Practice Patterns, Physicians' trends
- Abstract
Aims: This study surveys the current use of investigations for the management of glaucoma in hospital practice by UK ophthalmologists., Methods: A total of 1007 questionnaires were posted to all active NHS consultant ophthalmologists. They were asked to indicate the type of hospital (whether university (UTH) or general (DGH) hospital), glaucoma specialist status, and availability and use of automated perimetry, disc photography, HRT, GDx, OCT, and pachymetry., Results: A total of 493 completed questionnaires were received and 469 were analysed: 284 (60.6%) DGH, 185 (39.4%) UTH, 144 (30.7%) glaucoma specialists. There was good availability of automated perimetry (467, 99.6%), disc photography (420, 89.6%), pachymetry (374, 79.7%), OCT (212, 45.2%), HRT (206, 43.9%), and GDx (59, 12.6%). A total of 308 (65.7%) consultants had at least one digital imaging instrument available. The majority of consultants used SAP (347, 74.0%) and SITA-fast (282, 60.1%) for glaucoma suspects, and for monitoring glaucoma (283, 60.3% and 197, 42.0%, respectively). Some used Esterman (155, 33.0%) and Goldmann fields (90, 19.2%) in addition to SAP and SITA-fast for glaucoma suspects. Few consultants used short-wavelength automated perimetry and frequency-doubled perimetry. Of the three imaging tests, HRT was the most commonly used investigation for disc asymmetry, early glaucoma, glaucomatous progression, ocular hypertension, normal tension glaucoma, and unreliable visual fields (P<0.0001). Where pachymeters were available, 333 (89.0%) consultants and 117 (98.3%) glaucoma specialists used pachymetry in glaucoma management., Conclusions: There was some variation in the use of investigations for the diagnosis and management of glaucoma, reflecting the range of techniques available. SAP, SITA-fast, and pachymetry were the most commonly utilised investigations followed by HRT. Glaucoma specialist status, type of hospital, and presence of research influenced the availability and use of all investigations, except visual fields.
- Published
- 2008
- Full Text
- View/download PDF
37. Fine welding with lasers.
- Author
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MacLellan D
- Subjects
- Alloys chemistry, Alloys radiation effects, Biocompatible Materials chemistry, Biocompatible Materials radiation effects, Efficiency, Energy Transfer, Miniaturization methods, Lasers statistics & numerical data, Welding instrumentation
- Abstract
The need for micro joining metallic alloys for surgical instruments, implants and advanced medical devices is driving a rapid increase in the implementation of laser welding technology in research, development and volume production. This article discusses the advantages of this welding method and the types of lasers used in the process.
- Published
- 2008
38. [Laser information technologies in oncosurgery].
- Author
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Chissov VI, Panchenko VIa, Reshetov IV, Evseev AV, Poliakov AP, and Filiushin MM
- Subjects
- Humans, Russia, Information Services trends, Lasers statistics & numerical data, Medical Oncology methods
- Abstract
The introduction of laser information technologies to medical practice has improved the results of reconstructive and plastic operations in oncology thanks to a possibility to plan the surgery beforehand. Sixty-eight patients were operated on at Gertsen Moscow Research Oncology Institute between 2001 and 2006; 99 stereolithographic models were used to plan different stages of the surgical intervention. The tasks fulfilled with an individual stereolithographic model, may be relatively divided into three groups: 1) planning the resection stage; 2) planning the reconstructive surgery; 3) assessing the necessity to correct the complex autograft after the reconstructive surgery. The use of laser stereolithographic modelling in surgical treatment of patients with locally advanced malignancies made it possible to complete the reconstructive operation successfully in 98.4% of the patients, and rehabilitate functionally 88.6% of the patients.
- Published
- 2008
39. Lasers: slowly being accepted.
- Author
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Richards D
- Subjects
- Dental Cavity Preparation instrumentation, Humans, Dental Equipment, Lasers statistics & numerical data
- Published
- 2006
40. Revolutions and revelations.
- Author
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Lanzafame RJ
- Subjects
- Humans, Lasers statistics & numerical data, Photochemotherapy, Skin Aging, Wound Healing, Laser Therapy
- Published
- 2004
- Full Text
- View/download PDF
41. Clinical study of the use of the laser fluorescence device DIAGNOdent for detection of occlusal caries in children.
- Author
-
Anttonen V, Seppä L, and Hausen H
- Subjects
- Adolescent, Analysis of Variance, Child, Dental Caries Activity Tests, Dental Enamel pathology, Dentin pathology, Fluorescence, Humans, Molar pathology, Observer Variation, Radiography, Bitewing, Reproducibility of Results, Sensitivity and Specificity, Dental Fissures diagnosis, Lasers statistics & numerical data
- Abstract
Diagnosis of non-cavitated occlusal caries is generally considered problematic. The aim of this study was to evaluate the utility of the laser fluorescence device DIAGNOdent as part of routine dental check-ups in children. A total of 613 occlusal surfaces on permanent molars and 436 surfaces on primary molars in children aged 7-8 (n = 55) and 13-14 years (n = 54) were examined visually, using DIAGNOdent and for most 13- to 14-year-olds also using radiographs. The teeth were not cleaned professionally before examination. To provide a gold standard for carious teeth, the depth of the caries lesion was determined in those lesions that were judged visually to need opening by drilling (51 teeth). The higher the visual score, the higher were the mean DIAGNOdent values, but in each visual category the variation among values was large. The presence of a clear sealant did not affect DIAGNOdent measurements. The values for permanent and primary molars differed slightly. For permanent teeth, Youden's index value was highest (60%) at a cut-off value of 30, which indicates that the overall performance for DIAGNOdent in detecting dentinal caries was best at this point. Using this cut-off, sensitivity was 92% and specificity 69% with visual examination for validation, while sensitivity was 92% and specificity 82% with validation by fissure opening. Of the three methods, radiographic examination was the least accurate. In routine dental check-ups of children, DIAGNOdent appears to be useful as an adjunct to visual examination., (Copyright 2003 S. Karger AG, Basel)
- Published
- 2003
- Full Text
- View/download PDF
42. Hygienists using lasers.
- Author
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Clitter C
- Subjects
- Humans, United Kingdom, Dental Hygienists education, Dental Hygienists legislation & jurisprudence, Dental Prophylaxis instrumentation, Lasers statistics & numerical data
- Published
- 2002
- Full Text
- View/download PDF
43. Impairment of cytoskeleton-dependent vesicle and organelle translocation in green algae: combined use of a microfocused infrared laser as microbeam and optical tweezers.
- Author
-
Holzinger A, Monajembashi S, Greulich KO, and Lütz-Meindl U
- Subjects
- Cell Nucleus physiology, Chlorophyta physiology, Cytoskeleton, Lasers statistics & numerical data, Micromanipulation methods, Models, Theoretical, Organelles ultrastructure, Radiation, Cell Nucleus ultrastructure, Chlorophyta cytology, Micromanipulation instrumentation
- Abstract
A Nd-YAG laser at 1064 nm is used as optical tweezers to move intracellular objects and a laser microbeam to cause impairment of cytoskeleton tracks and influence intracellular motions in desmidiaceaen green algae. Naturally occurring migrations of large nuclei are inhibited in Micrasterias denticulata and Pleurenterium tumidum when the responsible microtubules are targeted with a laser microbeam generating 180 mW power in the focal plane. Impairment of the microtubule tracks appears to be irreversible, as the nucleus cannot pass the former irradiated area in Pleurenterium or remains abnormally dislocated in Micrasterias. The actin filament-dependent movement of secretory vesicles and smaller particles can be manipulated by the same IR-laser at 90 mW when functioning as optical tweezers. In Closterium lunula particles are displaced from their cytoplasmic tracks for up to 10 micro m but return to their tracks immediately after removing the light pressure gained by the optical tweezers. The cytoplasmic tracks consist of actin filament cables running parallel to the longitudinal axis of Closterium cells as depicted by Alexa phalloidin staining and confocal laser scanning microscopy. Dynamics and extensibility of the cytoplasmic strands connecting particles to the tracks are also demonstrated in the area of large vacuoles which are surrounded by actin filament bundles. In Micrasterias trapping of secretory vesicles by the optical tweezers causes irreversible malformations of the cell shape. The vesicle accumulation itself dissipates within 30 s after removing the optical tweezers, also indicating reversibility of the effects induced, in the case of actin filament-mediated processes.
- Published
- 2002
- Full Text
- View/download PDF
44. Hygienists using lasers?
- Author
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Prebble M
- Subjects
- Dental Equipment statistics & numerical data, Dental Prophylaxis instrumentation, Humans, United Kingdom, Dental Hygienists legislation & jurisprudence, Lasers statistics & numerical data
- Published
- 2002
45. The challenge offered by X-ray lasers.
- Author
-
Hajdu J
- Subjects
- Biology trends, Electrons, Lasers supply & distribution, Synchrotrons economics, Synchrotrons supply & distribution, United States, X-Rays, Biology methods, Lasers statistics & numerical data, Synchrotrons statistics & numerical data
- Published
- 2002
- Full Text
- View/download PDF
46. Ethical considerations concerning laser medicine.
- Author
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Raulin C, Greve B, and Raulin S
- Subjects
- Dermatology standards, Education, Medical, Continuing standards, Germany, Humans, Lasers statistics & numerical data, Patient Education as Topic, Surgery, Plastic education, Ethics, Medical, Laser Therapy standards, Laser Therapy trends, Surgery, Plastic standards
- Published
- 2001
- Full Text
- View/download PDF
47. Practice management.
- Author
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Weiser MT
- Subjects
- Dental Staff education, Dentist-Patient Relations, Fees, Dental, Humans, Insurance Claim Reporting, Insurance, Dental, Laser Therapy, Marketing of Health Services, Technology, High-Cost, Dental Equipment economics, Lasers statistics & numerical data, Practice Management, Dental
- Abstract
Laser treatment is now state-of-the-art in many disciplines of dentistry and is rapidly being recognized as the standard of care for many procedures. Seamless, efficient, and successful integration of lasers into a dental practice takes time and effort on the part of the dentist. Restructuring of fee schedules to reflect superior laser-based care and an internal and external marketing plan are essential for the dentist to recoup his or her investment in this new technology. Training the staff in laser technology and becoming familiar with new reimbursement codes (for medical and dental insurance) may become necessary. The mission statement and practice philosophy of providing superior care with less discomfort now can be realized with the integration of lasers into a dental practice.
- Published
- 2000
48. Chromosomes are target sites for photodynamic therapy as demonstrated by subcellular laser microirradiation.
- Author
-
Liang H, Do T, Kasravi S, Aurasteh P, Nguyen A, Huang A, Wang Z, and Berns MW
- Subjects
- Aminolevulinic Acid therapeutic use, Animals, Cell Line, Dermatitis, Phototoxic, Fluorescence, Humans, Macropodidae, Microscopy, Fluorescence methods, Mitosis, Photosensitizing Agents therapeutic use, Subcellular Fractions, Tumor Cells, Cultured, Chromosomes, Human radiation effects, Lasers statistics & numerical data, Photochemotherapy
- Abstract
The present investigation has been undertaken to examine the possibility that the cell nucleus, and specifically the genetic material, is a target site for photodynamic therapy. PTK2 and Hep-2 cells are pretreated with a medium containing 15 microg/ml (0.09 mM) 5-aminolevulinic acid (ALA). Individual fluorescence images are recorded for each selected cell using a cooled charge-coupled device (CCD). A laser microbeam system generating 630 nm is used for subcellular-region irradiation of specific targets: chromosomes, the mitotic spindle, the perispindle region and the peripheral cytoplasm. Nuclei of interphase cells are also irradiated. Data comparing the sensitivities of the different subcellular microirradiation sites in ALA-treated mitotic cells demonstrate that under the irradiation conditions used, the chromosome is the most sensitive subcellular target followed by the perispindle region, the peripheral cytoplasm and spindle, and, lastly, the interphase nucleus.
- Published
- 2000
- Full Text
- View/download PDF
49. In this issue. Dermatologic laser surgery.
- Author
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Nelson JS
- Subjects
- Humans, Laser Therapy instrumentation, Dermatology trends, Laser Therapy methods, Laser Therapy trends, Lasers statistics & numerical data, Skin Diseases surgery
- Published
- 2000
- Full Text
- View/download PDF
50. Imaging superficial tissues with polarized light.
- Author
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Jacques SL, Roman JR, and Lee K
- Subjects
- Humans, Image Enhancement methods, Liver, Microspheres, Muscle, Skeletal, Optics and Photonics, Polystyrenes, Skin, Lasers statistics & numerical data, Light, Photography instrumentation, Photography methods
- Abstract
Objective: Polarized light can be used to obtain images of superficial tissue layers such as skin, and some example images are presented. This study presents a study of the transition of linearly polarized light into randomly polarized light during light propagation through tissues., Study Design/materials and Methods: The transition of polarization was studied in polystyrene microsphere solutions, in chicken muscle (breast) and liver, and in porcine muscle and skin. The transition is discussed in terms of a diffusion process characterized by an angular diffusivity (radians(2)/mean free path) for the change in angular orientation of linearly polarized light per unit optical path traveled by the light., Results: Microsphere diffusivity increased from 0.031 to 0.800 for diameters decreasing from 6.04 microm to 0.306 microm, respectively. Tissue diffusivity varied from a very low value (0.0004) for chicken liver to an intermediate value (0.055) for chicken and porcine muscle to a very high value (0.78) for pig skin., Conclusion: The results are consistent with the hypothesis that birefringent tissues randomize linearly polarized light more rapidly than nonbirefringent tissues. The results suggest that polarized light imaging of skin yields images based only on photons backscattered from the superficial epidermal and initial papillary dermis because the birefringent dermal collagen rapidly randomizes polarized light. This anatomic region of the skin is where cancer commonly arises., (Copyright 2000 Wiley-Liss, Inc.)
- Published
- 2000
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