WorldWideScience

Sample records for single piece lens

  1. Scleral fixation of a single-piece multifocal intraocular lens.

    Science.gov (United States)

    Can, Ertugrul; Basaran, M Resat; Gül, Adem

    2013-01-01

    We describe an ab interno technique for injector implantation of a one-piece multifocal intraocular lens (IOL). Transscleral fixation of multifocal posterior chamber IOL implantation using an injector with ab interno technique was performed in an eye of a 9-year-old girl who had undergone pars plana lensectomy 2 years before for bilateral lens subluxation with unknown etiology. No major complications were encountered during a 3-month follow-up of the patient and excellent centration was observed during the follow-up period. Her preoperative best spectacle-corrected distance visual acuity of 20/32 improved to uncorrected distance visual acuity of 20/25. Closed-loop design of IOL served the function of eyelets and position of the IOL was provided using only a 2-point fixation. Intraoperative position adjustment of the IOL provided an excellent centralization of multifocal IOL.

  2. Safety and effectiveness of a glistening-free single-piece hydrophobic acrylic intraocular lens (enVista)

    Science.gov (United States)

    Packer, Mark; Fry, Luther; Lavery, Kevin T; Lehmann, Robert; McDonald, James; Nichamin, Louis; Bearie, Brian; Hayashida, Jon; Altmann, Griffith E; Khodai, Omid

    2013-01-01

    Purpose To evaluate the safety and effectiveness of a single-piece hydrophobic acrylic intraocular lens (IOL; enVista model MX60; Bausch & Lomb, Rochester, NY, USA) when used to correct aphakia following cataract extraction in adults. Methods This was a prospective case series (NCT01230060) conducted in private practices in the US. Eligible subjects were adult patients with age-related cataract amenable to treatment with standard phacoemulsification/extracapsular cataract extraction. With follow-up of 6 months, primary safety and effectiveness end points included the rates of US Food and Drug Administration (FDA)-defined cumulative and persistent adverse events and the percentage of subjects who achieved best-corrected visual acuity (BCVA) of 20/40 or better at final visit. To evaluate rotational stability, subjects were randomized (1:1:1:1) to have the lens implanted in one of four axis positions in 45° increments. Results A total of 122 subjects were enrolled. The rate of cumulative and persistent adverse events did not significantly exceed historical controls, as per FDA draft guidance. At the final postoperative visit, all subjects (100%) achieved a BCVA of 20/40 compared with the FDA historical control of 96.7%. Rotation of the IOL between the two final follow-up visits was ≤5° for 100% of eyes, and refractive stability was demonstrated. A low evaluation of posterior capsule opacification score was demonstrated, and no glistenings of any grade were reported for any subject at any visit. Conclusion This study demonstrated the safety and effectiveness of the MX60 IOL. Favorable clinical outcomes included preserved BCVA, excellent rotational and refractive stability, no glistenings, and a low evaluation of posterior capsule opacification score. PMID:24109169

  3. Safety and effectiveness of a glistening-free single-piece hydrophobic acrylic intraocular lens (enVista

    Directory of Open Access Journals (Sweden)

    Packer M

    2013-09-01

    Full Text Available Mark Packer,1 Luther Fry,2 Kevin T Lavery,3 Robert Lehmann,4 James McDonald,5 Louis Nichamin,6 Brian Bearie,7,† Jon Hayashida,8 Griffith E Altmann,8 Omid Khodai8 1Department of Ophthalmology, Oregon Health and Science University, Eugene, OR, USA; 2University of Kansas Medical Center, Kansas City, KS, USA; 3Wayne State University, Detroit, MI, USA; 4Baylor College of Medicine, Houston, TX, USA; 5University of Arkansas for Medical Sciences, Little Rock, AR, USA; 6Laurel Eye Clinic, Brookville, PA, USA; 7Grand Rapids Eye Institute, Grand Rapids, MI, USA; 8Bausch & Lomb, Aliso Viejo, CA, USA †Brian Bearie passed away on March 9, 2011 Purpose: To evaluate the safety and effectiveness of a single-piece hydrophobic acrylic intraocular lens (IOL; enVista model MX60; Bausch & Lomb, Rochester, NY, USA when used to correct aphakia following cataract extraction in adults. Methods: This was a prospective case series (NCT01230060 conducted in private practices in the US. Eligible subjects were adult patients with age-related cataract amenable to treatment with standard phacoemulsification/extracapsular cataract extraction. With follow-up of 6 months, primary safety and effectiveness end points included the rates of US Food and Drug Administration (FDA-defined cumulative and persistent adverse events and the percentage of subjects who achieved best-corrected visual acuity (BCVA of 20/40 or better at final visit. To evaluate rotational stability, subjects were randomized (1:1:1:1 to have the lens implanted in one of four axis positions in 45° increments. Results: A total of 122 subjects were enrolled. The rate of cumulative and persistent adverse events did not significantly exceed historical controls, as per FDA draft guidance. At the final postoperative visit, all subjects (100% achieved a BCVA of 20/40 compared with the FDA historical control of 96.7%. Rotation of the IOL between the two final follow-up visits was ≤5° for 100% of eyes, and refractive

  4. Scleral Fixation of a One-Piece Toric Intraocular lens

    Science.gov (United States)

    Emanuel, Matthew E.; Randleman, J. Bradley; Masket, Samuel

    2013-01-01

    Purpose To describe a novel technique for toric intraocular lens (IOL) repositioning and fixation in the absence of adequate capsular support Methods Case report and literature review Results Two cases are presented with scleral fixation of a one-piece toric IOL (SN6AT series, Alcon Inc.) In both cases, toric IOLs initially placed within the capsular bag became decentered due to poor capsular support and/or posterior capsule rupture. To avoid the potential complications of lens explantation and maintain the astigmatic benefits of the toric IOL, scleral fixation of the lenses was performed. The Hoffman technique was used to create reverse scleral pockets without conjunctival dissection. A 10-0 suture was used to capture and then secure the lens haptics in a lasso-type fashion. Sutures were then buried within the previously created scleral pockets. Both patients had well centered lenses postoperatively and have remained stable at last follow-up, up to thirty months postoperatively. Conclusion In the absence of adequate capsular support, scleral fixation is a viable option for one-piece toric IOL fixation to avoid IOL explanation PMID:23380416

  5. Refractive predictability of a 3-piece intraocular lens platform versus its 1-piece counterpart.

    Science.gov (United States)

    Mednick, Zale D; Varma, Devesh K; Campos-Möller, Xavier; Ahmed, Iqbal Ike K

    2017-04-01

    To compare the refractive outcomes of a 3-piece acrylic intraocular lens (IOL) with its 1-piece counterpart after phacoemulsification with in-the-bag implantation. Retrospective chart review. One-hundred twenty-six eyes of 95 patients were analyzed in the study, including 60 eyes of 43 patients receiving a 3-piece IOL and 66 eyes of 52 patients receiving a 1-piece IOL. Randomized chart review of all patients who underwent uncomplicated phacoemulsification with in-the-bag IOL implantation with either a 3-piece hydrophobic acrylic IOL (Tecnis ZA9003) or a 1-piece hydrophobic acrylic IOL (Tecnis ZCB00) between 2006 and 2014 in a tertiary ophthalmology care centre in Mississauga, Ontario. Preoperative visual acuity and refraction, anterior chamber depth, axial length, IOL design and power, predicted refraction, postoperative visual acuity, and refraction were recorded. Mean absolute error was 0.40 ± 0.27 in the ZA9003 group and 0.39 ± 0.35 in the ZCB00 group, with no statistically significant difference between the 2 IOLs (p = 0.86). Mean arithmetic error was 0.11 ± 0.47 D in the ZA9003 group and 0.01 ± 0.47 D in the ZCB00 group (p = 0.019). In the ZA9003 group, 23 (38%), 42 (70%), and 52 (87%) of 60 eyes were within 0.25, 0.50, and 0.75 D, respectively, of predicted postoperative refraction. In the ZCB00 group, 32 (48%), 46 (70%), and 56 (85%) of 66 eyes were within 0.25, 0.50, and 0.75 D, respectively, of predicted postoperative refraction (p = 0.2836, p = 1.00, p = 0.8044). The ZA9003 and the ZCB00 have similar mean absolute error and thus appear to have similar refractive predictability. Copyright © 2017 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.

  6. Scleral fixation of one piece intraocular lens by injector implantation.

    Science.gov (United States)

    Can, Ertugrul; Basaran, Resat; Gul, Adem; Birinci, Hakki

    2014-08-01

    With an ab-interno technique of transscleral suturing of current one-piece posterior chamber intraocular lenses (PC IOLs) by injector implantation in the absence of capsular support, we aimed to demonstrate the possibility of the implantation of one-piece acrylic PC IOLs that might be produced in the future for only scleral fixation through small clear corneal incision. Case report and literature review. This procedure has been performed in eight aphakic eyes with four different types of IOLs. Good centration was achieved with minimal technical effort. All patients had well-centered and stable lenses postoperatively during 9-18 months follow-up. We managed to decrease the risks of surgical trauma and intricate surgical maneuvers requirement. With this technique, excessive fluid leakage and consecutive hypotony can be minimized.

  7. Early clinical experience with a new preloaded one-piece intraocular lens in paediatric cataract surgery.

    Science.gov (United States)

    Gosling, D B; Chan, T K J

    2016-09-01

    PurposeTo report the clinical experience of using the Tecnis PCB00 (Abbott Medical Optics, Santa Ana, CA, USA) preloaded one-piece intraocular lens (IOL) in the setting of a tertiary referral centre for paediatric cataract.MethodsA retrospective case note review of all paediatric cataract surgeries using the Tecnis PCB00 IOL, at a single UK paediatric ophthalmology department.ResultsNine eyes in seven patients received the IOL between December 2014 and January 2016. All patients underwent lens aspiration and insertion of the IOL 'in the bag.' The indications for surgery included developmental cataract (8/9) and traumatic cataract (1/9). Mean age at the time of surgery was 7 years (range 2-14). The median improvement in logMAR best-corrected visual acuity was 0.475 (range 0.250-1.500). The mean follow-up duration was 5 months (range 1-13). No operative or post-operative complications occurred as a result of using the device.ConclusionThe Tecnis PCB00 preloaded IOL appears to be a safe and effective device in treating paediatric cataract.

  8. Pieces

    DEFF Research Database (Denmark)

    Jensen, Henrik

    1990-01-01

    The report presents results from the SIP project (System Representation in Process Control). PIECES is a graphical, interactive user interface system designed and programmed as a tool for building, manipulating and using a Multilevel Flow Model (MFM - Morten Lind, Tecnical University of Denmark......). An MFM describes a plant by describing the condition and the flow of its materials (mass, energy), which form the process. Pieces is programmed in Smalltalk. This report describes the programme, its hierarchy of classes and the methods of the classes. This report is 2 of 2. Report 1: Design of PIECES...

  9. Immediate loading with single-piece implant following extraction

    Directory of Open Access Journals (Sweden)

    Hemlata Dwivedi

    2017-01-01

    Full Text Available Although dental implantology had evolved over a number of years, many dental surgeons are unaware of the concept of immediate loading with the use of one-piece implant that began in the early 1960s. The goal of successful prosthodontics rehabilitation is to provide function, esthetics, and comfort to the patient. The aim of this literature is to provide an overview of one-piece implant, with its advantages and disadvantages over conventional two-piece implant. Immediate prosthetic of a one-piece system allows for a better tissue healing and better adhesion of gingival mucosa to form a collar which is healthy and adherent to the implant, avoiding a second surgical procedure, and also includes a very important aspect esthetics. This article describes a case report of immediate loading with single-piece implant following extraction.

  10. Clinical properties of a novel, glistening-free, single-piece, hydrophobic acrylic IOL

    Directory of Open Access Journals (Sweden)

    Packer M

    2014-02-01

    Full Text Available Mark Packer,1 Mohan Rajan,2 Edoardo Ligabue,3 Peter Heiner4 1Oregon Health and Science University, Portland, OR, USA; 2Rajan Eye Care Hospital Pvt Ltd, Chennai, India; 3Ophthalmology Department, Centro Diagnostico Italiano, Milan, Italy; 4Bond University Medical School, Robina, QLD, Australia Abstract: A new, single-piece, hydrophobic acrylic lens – the first constructed with a lens optic and haptics comprised of a hydroxyethyl methacrylate-polyethylene glycol phenyl ether acrylate–styrene copolymer, cross-linked with ethylene glycol dimethacrylate, and labeled as "glistening-free" – was recently introduced globally. Glistenings have been a significant source of clinical concern with previous hydrophobic lens designs. This new monofocal lens provides enhanced, clear optics for lens-based surgery. The superior optical clarity of this lens is achieved through the elimination of glistenings, enhanced surface durability, high refractive index, a high Abbe number, and an aspheric design. Additionally, the lens design reduces the risk of developing posterior capsule opacification. Keywords: glistenings, monofocal hydrophobic acrylic, IOL, aspheric

  11. Pieces

    DEFF Research Database (Denmark)

    Jensen, Henrik

    1990-01-01

    The report presents results from the SIP project (System Representation in Process Control). PIECES is a graphical, interactive user interface system designed and programmed as a tool for building, manipulating and using a Multilevel Flow Model (MFM - Morten Lind, Tecnical University of Denmark...

  12. Pieces

    DEFF Research Database (Denmark)

    Jensen, Niels Henrik

    1990-01-01

    The report presents results from the SIP project (System Representation in Process Control). PIECES is a graphical, interactive user interface system designed and programmed as a tool for building, manipulating and using a Multilevel Flow Model (MFM - Morten Lind, Tecnical University of Denmark)....

  13. Visual performance of the Tecnis one-piece lens ZCB00.

    Science.gov (United States)

    Wahba, Sherein S; Riad, Riad F; Morkos, Fathy F; Hassouna, Abdallah K; Roshdy, Maged M

    2011-01-01

    The aspheric, one-piece design of the Tecnis® ZCB00 intraocular lens provided higher mesopic contrast sensitivity and relatively constant refraction at different pupil sizes compared to the Sensar® AR40e. Comparing the impact on functional vision of the aspheric Tecnis® ZCB00 one-piece lens compared to the spherical Sensar® AR40e three-piece lens. National Eye Hospital, Cairo, Egypt. In this prospective study, we implanted 32 Tecnis ZCB00 (Abbott Medical Optics, Santa Ana, CA) and 30 Sensar AR40e (Pharamacia and Upjohn LLC, North Peapack, NJ) lenses. Twenty-three patients in the ZCB00 group and 13 patients in the AR40e group provided reliable, reproducible data, and were therefore included in the statistical analysis. After 8 weeks, we measured photopic contrast sensitivity (PCS) at 85 cd/m(2) and mesopic contrast sensitivity (MCS) at 5 cd/m(2). Uncorrected and best-corrected visual acuity were measured. Myopic shift was analyzed by comparing the manifest refraction spherical equivalent at 3 days and 8 weeks after surgery in the normal and dilated pupil. The Tecnis ZCB00 group showed significantly better MCS than the Sensar AR40e group at a spatial frequency of six cycles per degree (cpd) (P = 0.037), but not at 3, 12, or 18 cpd (P = 0.299, P = 0.226, and P = 0.396, respectively). There were no significant differences between groups in corrected distance visual acuity (P = 0.175) or PCS at 3, 6, 12, or 18 cpd spatial frequencies (P = 0.440, P = 0.176, P = 0.365, and P = 0.251, respectively). The ZCB00 group showed less myopic shift in normal and dilated pupils between 3 days and 8 weeks after surgery compared to the AR40e group, but this difference was not significant. The Tecnis one-piece ZCB00 provided higher MCS at moderate spatial frequency than the three-piece Sensar AR40e, and was associated with relatively constant refraction at different pupil sizes.

  14. SCLERAL SUTURE FIXATION TECHNIQUE FOR ONE-PIECE ACRYLIC INTRAOCULAR LENS.

    Science.gov (United States)

    Leung, Ella H; Mohsenin, Amir; Smiddy, William E

    2016-12-14

    To apply a previously published scleral fixation technique to secure one-piece acrylic intraocular lenses (IOLs) to the sclera. Retrospective, consecutive, noncomparative case series. All patients (16 eyes of 15 patients) who underwent scleral fixation of 1-piece acrylic IOLs using the loop method from 2014 to 2016 were included. The mean follow-up was 8.1 months. Repositioning of dislocated 1-piece acrylic IOLs was performed in 8 eyes, a primary implantation in 5 eyes, and IOL exchange in 3 eyes. All IOLs remained well-centered postoperatively. The vision improved from an initial best-corrected visual acuity of 0.97 ± 0.74 logMAR (Snellen equivalent ≈20/190) to 0.47 ± 0.49 logMAR (≈20/60, P = 0.031) at the last follow-up. The postoperative complications were self-limited. The previously reported scleral suture fixation technique can be readily applied to one-piece acrylic IOLs.

  15. Power prediction for one-piece and three-piece intraocular lens implantation after cataract surgery in patients with chronic angle-closure glaucoma: a prospective, randomized clinical trial.

    Science.gov (United States)

    Rhiu, Soolienah; Lee, Eun Suk; Kim, Tae-im; Lee, Hye Sun; Kim, Chan Yun

    2012-12-01

    To assess the accuracy of intraocular lens (IOL) power prediction for cataract surgery in chronic angle-closure glaucoma (CACG) patients with different IOLs' implantation. This prospective randomized clinical trial included 45 eyes with CACG and 48 eyes with normal controls undergoing cataract surgery. In the CACG group, 23 eyes (51%) had three-piece IOL implantation and 22 eyes (49%) had one-piece IOL implantation. In the normal control group, 25 eyes (52%) had three-piece IOL implantation and 23 eyes (48%) had one-piece IOL implantation. Using the SRK/T formula, the mean difference between the predicted and actual postoperative spherical equivalent [mean absolute error (MAE)] was obtained and converted to natural logarithm (ln) for statistical analysis. The power of the implanted IOL was calculated to predict postoperative SE using three formulas: SRK II, Holladay II and Hoffer Q by post hoc analysis in each group. The predictive accuracy of each formula was analysed by comparing the lnMAE. In the one-piece IOL group, there was no difference in lnMAE between the CACG and normal control group (p = 0.314). In the three-piece IOL group, the lnMAE of the CACG group was larger than that of the normal control group (p one-piece IOL group. Implantation of one-piece IOLs provides similar power prediction accuracy comparable to normal cataract patients; this result may be explained by the IOL haptic configuration or design. © 2012 The Authors. Acta Ophthalmologica © 2012 Acta Ophthalmologica Scandinavica Foundation.

  16. Findings of a Four-Year Randomized Controlled Clinical Trial Comparing Two-Piece and One-Piece Zirconia Abutments Supporting Single Prosthetic Restorations in Maxillary Anterior Region

    Directory of Open Access Journals (Sweden)

    Guerino Paolantoni

    2016-01-01

    Full Text Available The purpose of this randomized controlled study is to investigate the clinical results obtained over four years and incidence of complications associated with one- versus two-piece custom made zirconia anchorages, in single tooth implant-supported restorations of the maxillary anterior region. Sixty-five patients, with a total of 74 missing maxillary teeth, were selected in the period from February 2007 to July 2010. Two different ways of custom made zirconia abutment and final prosthetic restoration were evaluated: a standard zirconia abutment associated with a pressed layer of lithium disilicate with an all-ceramic cemented restoration versus one-piece restoration with the facing porcelain fired and pressed straight to the custom made zirconia abutment. In 29 cases, the restoration consisted of an all-ceramic restoration for cementation (two pieces; in 45 cases the restoration was a screw-retained restoration (one piece. Three all-ceramic restorations broke during the observation time. Two one-piece restorations fractured after 26 months. At follow-up examination there were no significant differences between one-piece and two-piece groups regarding the PI, BI, and MBL. Awaiting studies with longer follow-up times, a careful conclusion is that zirconia anchorages for single-implant restorations seem to demonstrate good short-term technical and biological results.

  17. Findings of a Four-Year Randomized Controlled Clinical Trial Comparing Two-Piece and One-Piece Zirconia Abutments Supporting Single Prosthetic Restorations in Maxillary Anterior Region

    Science.gov (United States)

    Paolantoni, Guerino; Marenzi, Gaetano; Blasi, Andrea; Mignogna, Jolanda; Sammartino, Gilberto

    2016-01-01

    The purpose of this randomized controlled study is to investigate the clinical results obtained over four years and incidence of complications associated with one- versus two-piece custom made zirconia anchorages, in single tooth implant-supported restorations of the maxillary anterior region. Sixty-five patients, with a total of 74 missing maxillary teeth, were selected in the period from February 2007 to July 2010. Two different ways of custom made zirconia abutment and final prosthetic restoration were evaluated: a standard zirconia abutment associated with a pressed layer of lithium disilicate with an all-ceramic cemented restoration versus one-piece restoration with the facing porcelain fired and pressed straight to the custom made zirconia abutment. In 29 cases, the restoration consisted of an all-ceramic restoration for cementation (two pieces); in 45 cases the restoration was a screw-retained restoration (one piece). Three all-ceramic restorations broke during the observation time. Two one-piece restorations fractured after 26 months. At follow-up examination there were no significant differences between one-piece and two-piece groups regarding the PI, BI, and MBL. Awaiting studies with longer follow-up times, a careful conclusion is that zirconia anchorages for single-implant restorations seem to demonstrate good short-term technical and biological results. PMID:27027093

  18. Findings of a Four-Year Randomized Controlled Clinical Trial Comparing Two-Piece and One-Piece Zirconia Abutments Supporting Single Prosthetic Restorations in Maxillary Anterior Region.

    Science.gov (United States)

    Paolantoni, Guerino; Marenzi, Gaetano; Blasi, Andrea; Mignogna, Jolanda; Sammartino, Gilberto

    2016-01-01

    The purpose of this randomized controlled study is to investigate the clinical results obtained over four years and incidence of complications associated with one- versus two-piece custom made zirconia anchorages, in single tooth implant-supported restorations of the maxillary anterior region. Sixty-five patients, with a total of 74 missing maxillary teeth, were selected in the period from February 2007 to July 2010. Two different ways of custom made zirconia abutment and final prosthetic restoration were evaluated: a standard zirconia abutment associated with a pressed layer of lithium disilicate with an all-ceramic cemented restoration versus one-piece restoration with the facing porcelain fired and pressed straight to the custom made zirconia abutment. In 29 cases, the restoration consisted of an all-ceramic restoration for cementation (two pieces); in 45 cases the restoration was a screw-retained restoration (one piece). Three all-ceramic restorations broke during the observation time. Two one-piece restorations fractured after 26 months. At follow-up examination there were no significant differences between one-piece and two-piece groups regarding the PI, BI, and MBL. Awaiting studies with longer follow-up times, a careful conclusion is that zirconia anchorages for single-implant restorations seem to demonstrate good short-term technical and biological results.

  19. Comparative study of visual function and ocular aberrations of two different one-piece designed hydrophilic acrylic intraocular lens.

    Science.gov (United States)

    Zhao, Yuxin; Wang, Zhaoxia; Tian, Xia; Wang, Xuehong; Gao, Xining

    2017-05-30

    To determine whether the aspherical IOL, Tecnis ZCB00, can improve the visual quality by measuring visual acuity, wavefront aberrations, and contrast sensitivity. It was a retrospective case series. Patients who underwent phacoemulsification cataract surgery were divided into two groups. One group (Group TC) was implanted with one-piece aspherical acrylic IOL (Tecnis ZCB00, AMO); the other (Group SA) was implanted with one-piece spherical acrylic IOL (Sensar AAB00, AMO). Eighty-eight eyes were selected into this study, among them 43 eyes in 26 male cases and 45 eyes in 29 female cases. Thirty-six eyes in 23 cases were in Group TC, and 52 eyes in 32 cases were in Group SA. Three months postoperatively, aberrations were analyzed with i-Trace visual function analyzer (Tracy Technologies, USA). Contrast sensitivities were measured with Takaci-CGT-1000 contrast glare tester (Seiko, Japan). All the 88 eyes underwent phacoemulsification with intraocular lens implantation, without complications during or after surgery. Three months postoperatively, the uncorrected vision acuity in Group TC was significantly better than in Group SA (P = 0.007). At the pupil size of 5.0 mm, higher-order aberrations in Group TC were significantly higher than in Group SA (P = 0.02), especially the spherical aberration (Z 4 0 ) (P < 0.001); at the pupil size of 4.0 mm, Z 4 0 in Group SA was statistically higher than in Group TC (P < 0.001); at the pupil size of 3.0 mm, higher-order aberrations such as coma (Z 3 -1,1 ) and trefoil aberration (Z 3 -3,3 ) in Group SA were obviously higher than in Group TC (P = 0.01). In the low spatial frequency, the contrast sensitivity and the glare sensitivity in Group TC were significantly higher than in Group SA (P < 0.05). By the short-term follow-up (3 months), the aspherical acrylic IOL can reduce the higher-order aberrations (especially the spherical aberration) and increase the contrast sensitivity to improve the visual performance.

  20. A simple technique of intraocular lenses explantation for single-piece foldable lenses

    Directory of Open Access Journals (Sweden)

    Arup Bhaumik

    2017-01-01

    Full Text Available Foldable intraocular lenses (IOLs are most commonly used in modern-day cataract surgery. Explantation of these IOLs is not frequently encountered, but sometimes extreme situations may demand the same. Commonly explantation is achieved by bisecting the IOL inside the anterior chamber with a cutter and delivering the pieces out one by one. This may require corneal wound extension with associated damage and endothelial loss leading to visual deterioration. We devised a simple, innovative IOL explantation technique utilizing a modified Alcon A cartridge and snare. This can successfully refold the IOL to be explanted inside the eye and deliver it out through the same wound. The device has limitations with very thick optic lenses, multipiece, and silicon IOLs. In conclusion, we describe a simple, innovative, and reproducible technique to explant almost any single piece IOL without compromising the original surgery and yielding very satisfactory outcomes.

  1. A high excitation magnetic quadrupole lens quadruplet incorporating a single octupole lens for a low spherical aberration probe forming lens system

    Science.gov (United States)

    Dou, Yanxin; Jamieson, David N.; Liu, Jianli; Li, Liyi

    2018-03-01

    This paper describes the design of a new probe forming lens system consisting of a high excitation magnetic quadrupole lens quadruplet that incorporates a single magnetic octupole lens. This system achieves both a high demagnification and a low spherical aberration compared to conventional high excitation systems and is intended for deployment for the Harbin 300 MeV proton microprobe for applications in space science and ion beam therapy. This relative simplicity of the ion optical design to include a single octupole lens minimizes the risks associated with the constructional and operational precision usually needed for the probe forming lens system and this system could also be deployed in microprobe systems that operate with less magnetically rigid ions. The design of the new system is validated with reference to two independent ion optical computer codes.

  2. Detection of kinetic change points in piece-wise linear single molecule motion

    Science.gov (United States)

    Hill, Flynn R.; van Oijen, Antoine M.; Duderstadt, Karl E.

    2018-03-01

    Single-molecule approaches present a powerful way to obtain detailed kinetic information at the molecular level. However, the identification of small rate changes is often hindered by the considerable noise present in such single-molecule kinetic data. We present a general method to detect such kinetic change points in trajectories of motion of processive single molecules having Gaussian noise, with a minimum number of parameters and without the need of an assumed kinetic model beyond piece-wise linearity of motion. Kinetic change points are detected using a likelihood ratio test in which the probability of no change is compared to the probability of a change occurring, given the experimental noise. A predetermined confidence interval minimizes the occurrence of false detections. Applying the method recursively to all sub-regions of a single molecule trajectory ensures that all kinetic change points are located. The algorithm presented allows rigorous and quantitative determination of kinetic change points in noisy single molecule observations without the need for filtering or binning, which reduce temporal resolution and obscure dynamics. The statistical framework for the approach and implementation details are discussed. The detection power of the algorithm is assessed using simulations with both single kinetic changes and multiple kinetic changes that typically arise in observations of single-molecule DNA-replication reactions. Implementations of the algorithm are provided in ImageJ plugin format written in Java and in the Julia language for numeric computing, with accompanying Jupyter Notebooks to allow reproduction of the analysis presented here.

  3. Visual acuity and patient satisfaction at varied distances and lighting conditions after implantation of an aspheric diffractive multifocal one-piece intraocular lens.

    Science.gov (United States)

    Chang, Daniel H

    2016-01-01

    The aim of the study is to evaluate the visual acuity and patient satisfaction at varied distances under photopic and mesopic lighting conditions in patients bilaterally implanted with aspheric diffractive multifocal one-piece intraocular lenses. In this retrospective-prospective study, 16 patients with a mean age of 66.2±9.2 years (range: 50-81 years) who had undergone bilateral phacoemulsification surgery with implantation of a Tecnis multifocal one-piece intraocular lens (ZMB00) were evaluated. Monocular and binocular uncorrected and distance-corrected visual acuities were measured at distance (20 ft), intermediate (70-80 cm), and near (35-40 cm) under photopic (85 cd/m(2)) and mesopic (3 cd/m(2)) lighting conditions and were compared using the paired t-test. All patients also completed a subjective questionnaire. At a mean follow-up of 9.5±3.9 months, distance, near, and intermediate visual acuity improved significantly from preoperative acuity. Under photopic and mesopic conditions, 93.8% and 62.5% of patients, respectively, had binocular uncorrected intermediate visual acuity of 20/40 or better, and 62.5% and 31.3% of patients had binocular uncorrected near visual acuity of 20/20 or better. All patients were satisfied with their overall vision without using glasses and/or contact lenses when compared with before surgery. A total of 87.5% of patients reported no glare and 68.8% of patients reported no halos around lights at night. Tecnis multifocal one-piece intraocular lenses provide good distance, intermediate, and near visual acuity under photopic as well as mesopic lighting conditions. High levels of spectacle independence with low levels of photic phenomenon were achieved, resulting in excellent patient satisfaction.

  4. Single-piece maintenance procedures for the TITAN reversed-field pinch reactor

    International Nuclear Information System (INIS)

    Grotz, S.P.; Creedon, R.L.; Cooke, P.I.H.; Duggan, W.P.; Krakowski, R.A.; Najmabadi, F.; Wong, C.P.C.

    1987-01-01

    The TITAN reactor is a compact (major radius of 3.9 m and minor plasma radius of 0.6 m), high neutron wall loading (--18MW/m 2 ) fusion energy system based on the reversed-field pinch (RFP) concept. The TITAN-I fusion power core (FPC) is a lithium, self-cooled design with vanadium alloy (V-3Ti-1Si) structural material. The compact design of the TITAN fusion power core (FPC) reduces the system to a few small and relatively low mass components, making toroidal segmentation of the FPC unnecessary. A single-piece maintenance procedure in which the replaceable first wall and blanket is removed as a single unit is, therefore, possible. The TITAN FPC design provides for top access to the reactor with vertical lifts used to remove the components. The number of remote handling procedures is few and the movements are uncomplicated. The annual torus replacement requires that the reusable ohmic-heating coil set and hot-shield assembly be removed and temporarily stored in a hot cell. The used first wall and blanket assembly is drained and disconnected from the coolant supply system, then lifted to a processing room where it is cooled and prepared for Class-C waste burial. The new, pre-tested first wall and blanket assembly is then lowered into position and the removal procedure is reversed to complete the replacement process

  5. Optimized design and structural mechanics of a single-piece composite helicopter driveshaft

    Science.gov (United States)

    Henry, Todd C.

    In rotorcraft driveline design, single-piece composite driveshafts have much potential for reducing driveline mass and complexity over multi-segmented metallic driveshafts. The singlepiece shaft concept is enabled by the relatively high fatigue strain capacity of fiber reinforced polymer composites over metals. Challenges for single-piece driveshaft design lie in addressing the self-heating behavior of the composite due to the material damping, as well as, whirling stability, torsional buckling stability, and composite strength. Increased composite temperature due to self-heating reduces the composite strength and is accounted for in this research. The laminate longitudinal stiffness ( Ex) and strength (Fx) are known to be heavily degraded by fiber undulation, however, both are not well understood in compression. The whirling stability (a function of longitudinal stiffness) and the composite strength are strongly influential in driveshaft optimization, and thus are investigated further through the testing of flat and filament wound composite specimens. The design of single-piece composite driveshafts, however, needs to consider many failure criteria, including hysteresis-induced overheating, whirl stability, torsional buckling stability, and material failure by overstress. The present investigation uses multi-objective optimization to investigate the design space which visually highlights design trades. Design variables included stacking sequence, number of laminas, and number of hanger bearings. The design goals were to minimize weight and maximize the lowest factor of safety by adaptively generating solutions to the multi-objective problem. Several design spaces were investigated by examining the effect of misalignment, ambient temperature, and constant power transmission on the optimized solution. Several materials of interest were modeled using experimentally determined elastic properties and novel temperature-dependent composite strength. Compared to the

  6. Retrospective Study of Tapered One-Piece Implants Placed Over a Ten-Year Period in a Single Private Practice.

    Science.gov (United States)

    Minichetti, John C; D'Amore, Joseph C; Hong, Anna Y-J

    2018-04-01

    Today, clinicians have a variety of treatment modalities available to address the increasing number of implant procedures performed each year. Single-stage implant surgery is now commonly used in implant dentistry. With patients' demands for immediate restoration, the utilization of 1-piece implants is gaining acceptance. This article reports the results of tapered 1-piece implants (Zimmer Biomet) placed in a single practice over a 10-year period. A total of 33 1-piece dental implants were placed in 24 patients and provisionally restored out of occlusion at the time of surgery. All 33 implants were definitively restored with ceramometal crowns after 3 months of provisionalization. Implant survival and success rates were 100% after 2.6-10 years of follow-up. Only 1 minor complication of crestal bone remodeling occurred among the 33 implants placed. Adequately stabilized tapered 1-piece implants can be successfully restored out of occlusion at the time of implant placement and definitively loaded in occlusion 3 months without adversely affecting function or esthetics. Additional long-term controlled studies are recommended to further understand these findings.

  7. One-piece zirconia oral implants: one-year results from a prospective cohort study. 1. Single tooth replacement.

    Science.gov (United States)

    Kohal, Ralf-Joachim; Knauf, Marko; Larsson, Birgitta; Sahlin, Herman; Butz, Frank

    2012-06-01

    To investigate the clinical and radiographic outcome of a one-piece zirconia oral implant for single tooth replacement after 1 year. A total of 65 patients received a one-stage implant surgery with immediate temporization. Standardized radiographs were taken at implant insertion and after 1 year to monitor peri-implant bone loss. A univariate analysis of the influence of different baseline parameters on marginal bone loss from implant insertion to 12 months was performed. Soft tissue parameters were evaluated at prosthesis insertion and at the 1-year follow-up. After 1 year, three implants were lost, giving a cumulative survival rate of 95.4%. The marginal bone loss after 1 year was 1.31 mm. Thirty-four per cent of the implants lost at least 2 mm bone, and 14% more than 3 mm. The univariate analysis could not depict any parameter influencing marginal bone loss. Probing depth, Clinical Attachment Level, Bleeding and Plaque Index decreased over 1 year. The cumulative survival rate of the presented ceramic implant was comparable to the reported survival rate of titanium implants when immediately restored. However, the frequency of increased radiographic bone loss (>2 mm) after 1 year was considerably higher as compared to conventional two-piece titanium implants. The presented zirconia implant can therefore not be recommended for clinical usage. © 2012 John Wiley & Sons A/S.

  8. Single-stage quintuplet for upgrading triplet based lens system: Simulation for Atomki microprobe

    Science.gov (United States)

    Ponomarov, Artem; Rajta, Istvan; Nagy, Gyula; Romanenko, Oleksandr V.

    2017-08-01

    Among different configurations of lens systems for nuclear microprobes, the most common one is a triplet of magnetic quadrupole lenses. Nowadays, microanalysis and material modification will undoubtedly benefit from an improvement in spatial resolution. This work presents the results of simulations for improvement of the Oxford Triplet lens system at the Atomki microprobe with consideration of its system parameters and measured beam brightness distribution. For this purpose, an additional single-unit doublet of lenses with two power supplies was introduced. Using earlier developed methods, such a quintuplet system was optimized in order to determine the parameters which provided the highest resolution for different current operational modes with the same microprobe geometry. The tolerances for lens positioning accuracy were also calculated. The obtained quintuplet parameters indicate a resolution improvement for the Atomki microprobe compared to the Oxford Triplet system and these results validate further experimental testing of the proposed quintuplet.

  9. Far infrared spectroscopy of Ge film deposited on a piece of Si wafer and single crystal Ge

    International Nuclear Information System (INIS)

    Roslan, M.; Ibrahim, K.; Wan Abdullah, A.K.

    1991-01-01

    The far infrared spectrum of thin polycrystalline film of Ge of approximately 10 μm deposited on a piece of Si wafer (99.99% purity) has been obtained using the far infrared Fourier transform spectroscopy system developed recently in our laboratory. The spectrum of Ge film from 180 to 480 cm -1 obtained after rationing against Si wafer spectrum at a resolution of about 1 cm -1 has been obtained. It is interesting to note that this thin film of Ge is extremely transparent to radiation in this region and phonon absorption processes as reported previously could not be observed due to thinness of the film. The spectrum of a single crystal of Ge (99.9% purity) and Ge-doped Li have revealed several absorption bands which we have assigned as due to 2-phonon and 3-phonon processes in Ge. The bands at 195, 273 and 287 cm -1 could not be assigned as phonon processes and at present we do not know the causes of these absorption bands

  10. Optical implementation of multifocal programmable lens with single and multiple axes

    Science.gov (United States)

    Romero, Lenny A.; Millán, María S.; Pérez-Cabré, Elisabet

    2011-01-01

    In this work we analyse the generation of a diffractive optical element (DOE) consisting of a multifocal Fresnel lens by means of an LCoS (liquid cristal on silicon) spatial light modulator (SLM). The multifocal lens is composed of a set of lenses of different focal length that share a common optical axis (coaxial combination) or have different axes in parallel (multi-axis combination). For both configurations, we present several ways to combine the phase distributions for three lenses with different focal lengths (f1, f2, f3), into a single-phase distribution addressed to the SLM. Numerical simulations were carried out along with the experimental analysis to corroborate the results.

  11. Safety and effectiveness of a glistening-free single-piece hydrophobic acrylic intraocular lens (enVista)

    OpenAIRE

    Packer, Mark; Fry,Luther; Lavery,Kevin T; Lehmann,Robert; Nichamin,Louis; Hayashida,Jon; Altmann,Griffith E; Khodai,Omid; McDonald,Jay

    2013-01-01

    Mark Packer,1 Luther Fry,2 Kevin T Lavery,3 Robert Lehmann,4 James McDonald,5 Louis Nichamin,6 Brian Bearie,7,† Jon Hayashida,8 Griffith E Altmann,8 Omid Khodai8 1Department of Ophthalmology, Oregon Health and Science University, Eugene, OR, USA; 2University of Kansas Medical Center, Kansas City, KS, USA; 3Wayne State University, Detroit, MI, USA; 4Baylor College of Medicine, Houston, TX, USA; 5University of Arkansas for Medical Sciences, Little Rock, AR, USA; 6Laurel Eye Clinic, B...

  12. Single-lens 3D digital image correlation system based on a bilateral telecentric lens and a bi-prism: validation and application.

    Science.gov (United States)

    Wu, Lifu; Zhu, Jianguo; Xie, Huimin

    2015-09-10

    By using the principle of stereovision, 3D digital image correlation (3D-DIC) can determine the 3D morphology and deformation of a target and has been widely used in experimental mechanics as a noncontact 3D measurement technique. To eliminate the limitations of the conventional 3D-DIC system, this study proposes a calibration-free single-lens 3D-DIC system based on a bilateral telecentric lens and a bi-prism. The performance of the proposed system is verified by tests of rigid-body translation along the out-of-plane direction. As a comparison, the same rigid-body translations are measured using a single-entocentric-lens 3D-DIC system. The results show that the measurement accuracy of the proposed system is higher than that of the entocentric-lens-based one. As an application, the proposed system is used to measure the thermal linear expansion of a ceramic plate at elevated temperatures. The reasonable measurement results verify its applicability in deformation measurements, even in high-temperature environments.

  13. Three pieces

    OpenAIRE

    Palomas Pubill, Alejandro

    1992-01-01

    The following Master's Thesis represents the culmination of two years' work in the UCSD department of music. The three pieces, Bicusp[i think you've got]id, Sequitur, non?, and Solo for horn, appear in order of completion, the first two having been composed for juries, the last for a fellow student's recital. My efforts in composition during the program have focused on the exploration of chaotic states, energy transfer, transformative trajectories, and non-traditional sound worlds. One can se...

  14. Conjunctival lymphoma: Results and treatment with a single anterior electron field. A lens sparing approach

    International Nuclear Information System (INIS)

    Dunbar, S.F.; Linggood, R.M.; Doppke, K.P.; Duby, A.; Wang, C.C.

    1990-01-01

    Lymphoma of the conjunctiva is rare. It presents in older patients as a mass lesion and usually remains localized. Surgery is limited to biopsy, and radiation therapy is the definitive treatment of choice. The entire conjunctiva is treated. Relatively high doses (approximately 30 Gy) are required for local control, which may lead to cataract formation. Twelve patients with conjunctival lymphoma were treated at the Massachusetts General Hospital between 1979 and 1988. Ten of 12 patients presented with a unilateral lesion; 2 of 12 with bilateral lesions. Two of 12 patients were found to have systemic disease at the time of presentation. One patient developed conjunctival lymphoma 5 years after the diagnosis of generalized disease. Using electron beam, all patients were treated with a single anterior circular field to total doses ranging from 24 Gy to 30 Gy delivered in 8 to 16 fractions over 9 to 20 days. In all cases, the lens was shielded by a specially designed plastic contact lens bearing a 12 mm diameter lead shield. The lens dose was determined at varying depths beneath the shield for 6 MeV and 9 MeV electron beams and ranged from a minimum of 5% to an absolute maximum of 18% of the total dose delivered to the tumor. Local control was maintained in all patients with follow-up to 9 1/2 years. One patient relapsed distantly 3 years after treatment. One of 12 patients died of systemic disease 4 years after treatment of the ocular lesion. Two patients developed cataracts 4 and 5 years after treatment; one had bilateral cataract, although only one eye had been treated. Both patients were over 75 years old. In both cases, the cataracts were felt to be senile cataracts which are ophthalmologically and radiographically distinguishable from radiation induced lesions

  15. Lamp system with a single second-lens newly designed by using the least square method for 4 LEDs

    Science.gov (United States)

    Jo, Jae Heung; Ryu, Jae Myung; Hong, Chun Gang

    2014-05-01

    It is common for many companies to use multiple LEDs to enhance the brightness of a LED lamp and, in general, four LEDs are used in the LED lamp systems. Moreover, the second-lens must be used to obtain a straight uniform illumination from LED lights. Where four LEDs are used, four second-lenses are also assembled conventionally and those four units of second-lenses are manufactured from a single mold and assembled together with the LEDs. However, this study introduces a new method of using the Least Square Method to get a uniform illumination with the divergence angle of 40 degrees with a new single injection molded lens. Thanks to this optical design with a single lens, the assembling process of LED lamp system was simplified by eliminating the complicated assembly procedure. Also, the uniformity of illumination of this newly designed lamp system was less than 14.1%.

  16. 3D Imaging with a Single-Aperture 3-mm Objective Lens: Concept, Fabrication and Test

    Science.gov (United States)

    Korniski, Ron; Bae, Sam Y.; Shearn, Mike; Manohara, Harish; Shahinian, Hrayr

    2011-01-01

    There are many advantages to minimally invasive surgery (MIS). An endoscope is the optical system of choice by the surgeon for MIS. The smaller the incision or opening made to perform the surgery, the smaller the optical system needed. For minimally invasive neurological and skull base surgeries the openings are typically 10-mm in diameter (dime sized) or less. The largest outside diameter (OD) endoscope used is 4mm. A significant drawback to endoscopic MIS is that it only provides a monocular view of the surgical site thereby lacking depth information for the surgeon. A stereo view would provide the surgeon instantaneous depth information of the surroundings within the field of view, a significant advantage especially during brain surgery. Providing 3D imaging in an endoscopic objective lens system presents significant challenges because of the tight packaging constraints. This paper presents a promising new technique for endoscopic 3D imaging that uses a single lens system with complementary multi-bandpass filters (CMBFs), and describes the proof-of-concept demonstrations performed to date validating the technique. These demonstrations of the technique have utilized many commercial off-the-shelf (COTS) components including the ones used in the endoscope objective.

  17. Alveolar Bone Resorption Evaluation Around Single-piece Designed Bicortical Implants, Using Immediate Loading Protocol, Based on Orthopantomographs

    Directory of Open Access Journals (Sweden)

    Száva Dániel-Tamás

    2017-12-01

    Full Text Available Background: Inserting dental implants in severely atrophied jawbones is a great challenge for the dental practitioner. There are an increasing number of patients who choose dental implantanchored prosthetic restorations despite compromised bone quality and quantity. There have been numerous attempts in adapting implant design for the atrophic crestal bone. One-piece, needle-type basal implant design is a typical design for these cases. These implants are inserted in the remaining compact bone located in the basal aspect of the jawbones. If high primary stability is achieved, these implants are used for immediate loading protocol. From many points of view, this technique is based on contradictory principles compared to classic implant surgery and loading protocols. The aim of this study was to investigate the long-term success of basal one-piece short-diameter dental implants used for immediate loading protocol.

  18. Single lens photometric machine vision with 3D imaging for fiber-to-chip coupling.

    Science.gov (United States)

    Liu, Xu; Hu, Hongmei; Sun, Xiaohan

    2012-03-01

    A single lens photometric machine vision (SLPMV) optical microbench is presented and built for fiber-to-chip coupling. By a rotation mechanics in SLPMV, the multi-view-camera can scan the various surface status of the chips coupled. To realize 3D imaging more explicitly, the modified photometric stereo algorithm is proposed through acquiring the images of weak saturation, matching the scanning illuminative angles, and rectifying rectangularly the original images. The reconstructed images have had similar qualities as those obtained by scanning electron microscopy and have unveiled the detailed information obscured in the 2D images. For the InP-based optical waveguide chip coupled with wedge-shaped fiber, the insertion loss tested on the SLPMV is 3 dB less than one on the conventional testing station. The SLPMV could serve as a more cost-effective and compact scientific observation instrumentation in imaging informatics than commercial ones.

  19. Magnetic field shimming of a permanent magnet using a combination of pieces of permanent magnets and a single-channel shim coil for skeletal age assessment of children.

    Science.gov (United States)

    Terada, Y; Kono, S; Ishizawa, K; Inamura, S; Uchiumi, T; Tamada, D; Kose, K

    2013-05-01

    We adopted a combination of pieces of permanent magnets and a single-channel (SC) shim coil to shim the magnetic field in a magnetic resonance imaging system dedicated for skeletal age assessment of children. The target magnet was a 0.3-T open and compact permanent magnet tailored to the hand imaging of young children. The homogeneity of the magnetic field was first improved by shimming using pieces of permanent magnets. The residual local inhomogeneity was then compensated for by shimming using the SC shim coil. The effectiveness of the shimming was measured by imaging the left hands of human subjects and evaluating the image quality. The magnetic resonance images for the child subject clearly visualized anatomical structures of all bones necessary for skeletal age assessment, demonstrating the usefulness of combined shimming. Copyright © 2013 Elsevier Inc. All rights reserved.

  20. One-piece internal zirconia abutments for single-tooth restorations on narrow and regular diameter implants: A 5-year prospective follow-up study.

    Science.gov (United States)

    Nilsson, Andrée; Johansson, Lars-Åke; Lindh, Christina; Ekfeldt, Anders

    2017-10-01

    Studies have reported an increased risk for fractures of zirconia abutments compared with titanium abutments. The aim of this study was to evaluate single-tooth implant restorations with one-piece yttria-stabilized internal zirconia abutments on narrow and regular diameter implants up to 6 years after insertion. This study comprises 52 consecutively treated patients, with a median age of 19 years. In total, 59 narrow (3.3 mm) and 10 regular (4.1 mm) diameter implants were installed. Sixty-five all-ceramic crowns were cemented on implant-supported one-piece internal zirconia abutments and 4 restorations were screw-retained. Thirty-five patients with 48 implant restorations participated in the final examination and another 14 patients with 16 implant restorations were possible to reach and could be interviewed. The implant survival was 100% but the survival rate for the implant-supported ceramic restorations was lower, 87.5%. Three crowns (4.7%) were remade for different reasons. Five restorations (7.8%) were remade due to fracture of the internal one-piece zirconia abutment. Four of these fractures occurred in 3.3 mm implant abutments. Narrow diameter implants offer an opportunity to restore small single-tooth edentulous gaps. For esthetical reasons the choice of an abutment in zirconia can be favorable, but at least with the used implant system, there seems to be an increased risk for fracture. Most patients were very satisfied with the esthetics and function of their implant restorations. © 2017 Wiley Periodicals, Inc.

  1. Single Lens Dual-Aperture 3D Imaging System: Color Modeling

    Science.gov (United States)

    Bae, Sam Y.; Korniski, Ronald; Ream, Allen; Fritz, Eric; Shearn, Michael

    2012-01-01

    In an effort to miniaturize a 3D imaging system, we created two viewpoints in a single objective lens camera. This was accomplished by placing a pair of Complementary Multi-band Bandpass Filters (CMBFs) in the aperture area. Two key characteristics about the CMBFs are that the passbands are staggered so only one viewpoint is opened at a time when a light band matched to that passband is illuminated, and the passbands are positioned throughout the visible spectrum, so each viewpoint can render color by taking RGB spectral images. Each viewpoint takes a different spectral image from the other viewpoint hence yielding a different color image relative to the other. This color mismatch in the two viewpoints could lead to color rivalry, where the human vision system fails to resolve two different colors. The difference will be closer if the number of passbands in a CMBF increases. (However, the number of passbands is constrained by cost and fabrication technique.) In this paper, simulation predicting the color mismatch is reported.

  2. Decision Support System to Choose Digital Single Lens Camera with Simple Additive Weighting Method

    Directory of Open Access Journals (Sweden)

    Tri Pina Putri

    2016-11-01

    Full Text Available One of the technologies that evolve today is Digital Single Lens Reflex (DSLR camera. The number of products makes users have difficulties to choose the appropriate camera based on their criteria. Users may utilize several ways to help them choosing the intended camera such as using magazine, internet, and other media. This paper discusses about a web based decision support system to choose cameras by using SAW (Simple Additive Weighting method in order to make the decision process more effective and efficient. This system is expected to give recommendations about the camera which is appropriate with the user’s need and criteria based on the cost, the resolution, the feature, the ISO, and the censor. The system was implemented by using PHP and MySQL. Based on the result of questionnaire distributed to 20 respondents, 60% respondents agree that this decision support system can help users to choose the appropriate camera DSLR in accordance with the user’s need, 60% of respondents agree that this decision support system is more effective to choose DSLR camera and 75% of respondents agree that this system is more efficient. In addition, 60.55% of respondents agree that this system has met 5 Es Usability Framework.

  3. Temporary Piggyback Intraocular Lens Implantation Versus Single Intraocular Lens Implantation in Congenital Cataracts: Long-Term Clinical Outcomes.

    Science.gov (United States)

    Hwang, Sungsoon; Lim, Dong Hui; Lee, Soomin; Choi, Daye Diana; Chung, Eui-Sang; Chung, Tae-Young

    2018-04-01

    To report the long-term results of temporary piggyback IOL implantation in congenital cataract and to compare the clinical outcomes of temporary piggyback IOL with those of single IOL implantation. This is a retrospective, comparative, interventional study. The medical records of all consecutive patients who underwent cataract extraction and single or temporary piggyback IOL implantation within the first 3 years of life from 1999 to 2013 at Samsung Medical Center were reviewed. Twenty-eight eyes from 18 patients underwent single IOL implantation (monopseudophakia group), and 32 eyes of 20 patients underwent temporary piggyback IOL implantation in congenital cataract surgery (polypseudophakia group). The mean age at initial cataract surgery was 15.8 months in the monopseudophakia group and 11.1 months in the polypseudophakia group (P = 0.144). The average follow-up duration was 133 months in the monopseudophakia group and 120 months in the polypseudophakia group (P = 0.391). The best-corrected visual acuity at the last visit was 0.36 logMAR in the monopseudophakia group and 0.55 logMAR in the polypseudophakia group (P = 0.044). Four (14%) and 14 (44%) reoperations for complications within the anterior segment were performed in the monopseudophakia group and polypseudophakia group, respectively (P = 0.042). Four cases (14.3%) in the monopseudophakia group and 13 cases (40.6%) in the polypseudophakia group had a glaucoma-related adverse event (P = 0.086). Compared with primary single IOL implantation in congenital cataract, temporary piggyback IOL implantation produced worse visual acuity, higher reoperation rate, and higher risk of secondary glaucoma. Temporary piggyback IOL implantation does not have benefit in congenital cataract.

  4. 3D-printed adaptive acoustic lens as a disruptive technology for transcranial ultrasound therapy using single-element transducers

    Science.gov (United States)

    Maimbourg, Guillaume; Houdouin, Alexandre; Deffieux, Thomas; Tanter, Mickael; Aubry, Jean-François

    2018-01-01

    The development of multi-element arrays for better control of the shape of ultrasonic beams has opened the way for focusing through highly aberrating media, such as the human skull. As a result, the use of brain therapy with transcranial-focused ultrasound has rapidly grown. Although effective, such technology is expensive. We propose a disruptive, low-cost approach that consists of focusing a 1 MHz ultrasound beam through a human skull with a single-element transducer coupled with a tailored silicone acoustic lens cast in a 3D-printed mold and designed using computed tomography-based numerical acoustic simulation. We demonstrate on N  =  3 human skulls that adding lens-based aberration correction to a single-element transducer increases the deposited energy on the target 10 fold.

  5. Evaluation of a one-piece ceramic implant used for single-tooth replacement and three-unit fixed partial dentures: a prospective cohort clinical trial.

    Science.gov (United States)

    Jung, Ronald E; Grohmann, Philipp; Sailer, Irena; Steinhart, Yann-Niclas; Fehér, Aurel; Hämmerle, Christoph; Strub, Jörg Rudolf; Kohal, Ralf

    2016-07-01

    The aim of this clinical trial was to evaluate the safety and efficiency of a one-piece zirconia oral implant after 1 year of function. Two centers included 60 subjects in need of implant-supported single-tooth restorations or three-unit bridges. A total of 71 zirconia one-piece implants were placed and immediately restored with a temporary reconstruction for at least 2 months. The final veneered zirconia restorations were then cemented and followed for 6 months and 1 year after insertion of the restorations. At each visit, a clinical evaluation was performed to analyze biological parameters of the implants and the neighboring teeth. A standardized periapical radiograph was taken at implant insertion, at the placement of the restorations and at the 1-year follow-up. Sixty patients with 71 implants (48 in the mandible, 23 in the maxilla) were included in this study and provided with 11 bridges and 49 crowns. Two patients with three implants (one bridge and one single crown) could not be evaluated. One patient lost his implant 5 weeks after implant insertion. Based on 58 patients, the mean survival rate was 98.3% after one year when the implants of the two patients that did not show up were not counted as lost. The mean marginal bone loss from implant insertion to the 1-year follow-up after the final prosthetic restoration was 0.78 mm with a standard deviation of 0.79 mm. The probing depth around the implants increased from 2.7 mm at insertion of the prosthetic reconstruction to 3.5 mm one year after insertion. The probing depth around the adjacent teeth remained stable at 2.5 mm. At the 1-year recall, the difference was significant. The clinical attachment levels at implants and teeth were not different at the 1-year follow-up with 3.1 mm at tooth and implant sites. The presently tested one-piece ceramic implant was successful in replacing single tooth and three-unit gaps after one year of function. Further long-term data are necessary to verify these

  6. Early Loading of Single-Piece Implant for Partially Edentulous Posterior Arch: A Prospective One-Year Case Report

    Directory of Open Access Journals (Sweden)

    Amol Beldar

    2013-01-01

    Full Text Available Implant therapy is now well established, and there is an increasing need for shorter rehabilitation time. Original prerequisites of osseointegration have been reassessed to satisfy continuously increasing patient's expectation of reduced treatment time, improved esthetics, and increased comfort. Shorter healing time may be appropriate in some circumstances, and examples of early loading have been reported in animal and human studies. However, to date there are insufficient data to determine a universally acceptable opinion on early loading of implants for single-tooth replacement. This case report involves early loading, combined with construction of a restoration, inserted directly after 6 weeks of implant surgery and followup of one year.

  7. Early Loading of Single-Piece Implant for Partially Edentulous Posterior Arch: A Prospective One-Year Case Report

    Science.gov (United States)

    Beldar, Amol; Bhongade, Manohar L.; Byakod, Girish; Buregoni, Chandrashekar

    2013-01-01

    Implant therapy is now well established, and there is an increasing need for shorter rehabilitation time. Original prerequisites of osseointegration have been reassessed to satisfy continuously increasing patient's expectation of reduced treatment time, improved esthetics, and increased comfort. Shorter healing time may be appropriate in some circumstances, and examples of early loading have been reported in animal and human studies. However, to date there are insufficient data to determine a universally acceptable opinion on early loading of implants for single-tooth replacement. This case report involves early loading, combined with construction of a restoration, inserted directly after 6 weeks of implant surgery and followup of one year. PMID:23710375

  8. Comparison of decentration and tilt between one piece and three piece polymethyl methacrylate intraocular lenses

    Science.gov (United States)

    Hayashi, K.; Hayashi, H.; Nakao, F.; Hayashi, F.

    1998-01-01

    BACKGROUND—The extent of the decentration and tilt was prospectively compared between one piece polymethyl methacrylate (PMMA) and three piece PMMA intraocular lenses (IOLs) which were implanted in the capsular bag after performing continuous curvilinear capsulorhexis.
METHODS—91 patients underwent a one piece PMMA IOL implantation in one eye as well as the implantation of the three piece PMMA IOL with polyvinylidene fluoride loops in the opposite eye. The length of the lens decentration and the angle of the tilt were quantitated using the anterior eye segment analysis system (EAS-1000) at 1 week as well as 1, 3, and 6 months postoperatively.
RESULTS—The mean length of the decentration in the one piece IOL was smaller than that in the three piece IOL at 1 week (p=0.0092), 1 month (p=0.0044), 3 months (p=0.0069), and 6 months (p=0.0010) postoperatively. However, no significant difference was found in the degree of the tilt between the two types of IOLs throughout the observation periods.
CONCLUSION—These results clarified that the one piece PMMA IOL with rigid PMMA haptics implanted in the capsular bag provides a better centration than the three piece PMMA IOL with flexible haptics, whereas the tilt was the same between the two types of IOLs.

 Keywords: intraocular lens; decentration; tilt; continuous curvilinear capsulorhexis PMID:9640193

  9. Comparison of Nd: YAG capsulotomy rate between 1-piece and 3-piece acrylic intraocular lenses: A STROBE-compliant article.

    Science.gov (United States)

    Kim, Sun Young; Chung, Young Kwon; Shin, Hye Young; Lee, Mee Yon; Lee, Young-Chun; Kim, Su-Young

    2017-07-01

    The aim of the study is to compare Nd:YAG capsulotomy rate between acrylic 1- and 3-piece intraocular lenses. Among 924 eyes of 762 patients who received cataract surgery, we selected the 303 patients (404 eyes) implanted with an SN60WF 1-piece intraocular lens (Alcon, Fort Worth, TX) or a YA-60BBR 3-piece intraocular lens (Hoya Co., Tokyo, Japan). For intraindividual comparison, we enrolled the 17 patients implanted with an SN60WF in 1 eye and a YA-60BBR in the contralateral eye. We compared Nd:YAG capsulotomy rate between acrylic 1- and 3-piece intraocular lenses 24 months after the operation. Of the 404 eyes in this study, Nd:YAG capsulotomy was performed in 20 of 268 eyes (7.5%) in the SN60WF 1-piece intraocular lens group and 24 of 136 eyes (17.6%) in the YA-60BBR 3-piece intraocular lens group; the difference was statistically significant (P = .002). Among the 17 patients (34 eyes) who were implanted with 2 different inraocular lenses, Nd:YAG capsulotomy was performed in only 2 eyes (12%) in the SN60WF group and 9 eyes (53%) in the YA-60BBR group; the difference was statistically significant (P = .020).The authors found a significantly greater incidence of Nd:YAG capsulotomy in eyes who received 3-piece lenses compared with those who received 1-piece lenses.

  10. MISSING: BUBBLE CHAMBER LENS

    CERN Multimedia

    2001-01-01

    Would the person who borrowed the large bubble chamber lens from the Microcosm workshops on the ISR please return it. This is a much used piece from our object archives. If anybody has any information about the whereabouts of this object, please contact Emma.Sanders@cern.ch Thank you

  11. One-piece zirconia oral implants for single-tooth replacement: Three-year results from a long-term prospective cohort study.

    Science.gov (United States)

    Kohal, Ralf-Joachim; Spies, Benedikt C; Bauer, Annalena; Butz, Frank

    2018-01-01

    This 3-year report of a prospective long-term cohort investigation aimed to evaluate the clinical and radiographic outcomes of a one-piece zirconia oral implant for single-tooth replacement. Sixty-five patients received a 1-stage implant surgery with immediate temporization. Standardized radiographs were taken at implant insertion, after 1 year, and after 3 years to monitor peri-implant bone levels. A univariate analysis of the association of different baseline parameters on marginal bone loss from implant insertion to 36 months was performed. Soft-tissue parameters were evaluated at prosthesis insertion, after 6 months, after 1 year, and at the 3-year follow-up. After 3 years, six posterior site implants were lost, giving a cumulative survival rate of 90.8%. The mean marginal bone loss was 1.45 mm; 35% of the implants lost at least 2 mm bone, and 22% more than 3 mm. The univariate analysis did not identify any parameter associated with marginal bone loss. Probing depth, clinical attachment level, and bleeding index increased over 3 years, and plaque index decreased. The low survival rate of the presented ceramic implant and especially the high frequency of advanced bone loss are noticeable but remain unexplained. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Transition piece for joining together tubular pieces

    International Nuclear Information System (INIS)

    Holko, K.H.

    1981-01-01

    A transition piece for joining together tubular pieces formed respectively from a low alloy or carbon steel and a high temperature alloy containing at least 16% chromium includes a plurality of tubular parts welded together and formed from materials of selected composition with a maximum chromium content difference of 5% between adjacent parts when the chromium content of each part is below 10% and a maximum chromium difference of 7% between adjacent parts when the chromium content of either part is above 10%. The transition parts are also graded as to such characteristics as thermal expansion coefficient. The transition parts at opposite ends of the transition joint have chromium percentages similar to the tubular pieces to which they are to be joined. The parts may be joined by fusion and/or friction welding and parts may be formed by fusion weld deposition. (author)

  13. Analysis of crestal bone loss around single piece ball attachment implant placed bilaterally in canine region and wear of O-ring in implant supported overdenture: Three year follow-up.

    Science.gov (United States)

    Raza, Fathima Banu; Vaidyanathan, Anand Kumar; Veeravalli, Padmanabhan T; Ravishankar, Subhiksha; Ali, Aashique S

    2018-03-06

    Single piece implant in fixed prosthesis is widely been evaluated, however, long term evaluation of crestal bone loss and the wear of O-ring in single piece ball attachment implant supported overdenture is yet to be evaluated PURPOSE: The present article evaluates the crestal bone loss around single piece ball attachment implants placed bilaterally in the canine region and the wear of O-ring in implant supported overdenture over a period of three years. Twelve completely edentulous patients between the age group of 55-65 years were selected. Two 3.3 mm × 13 mm myriad snap fit implants were placed in the mandibular interforaminal region. All the implants were conventionally loaded at three months after surgical placement. Intra-oral periapical radiographs were made and crestal bone loss was measured at the end of one year and three years. The elasticity and wear of O-Ring was assessed after three years of usage. The crestal bone loss showed no significant difference between the first and third year after implant placement. The mean bone loss at the end of third year was 1.5 mm. Analysis of O-ring for change in the elasticity showed reduction in displacement and a significant increase in maximum displacement and elongation. The area of O-ring and yield stress did not show any changes from the standard value. Compression set damage was observed in the O-ring at the end of three years. The present study shows that the bilateral single piece implant supported overdenture has a success rate equivalent to the two piece implant supported overdenture and is a viable treatment option. © 2018 Wiley Periodicals, Inc.

  14. Unique rod lens/video system designed to observe flow conditions in emergency core coolant loops of pressurized water reactors

    International Nuclear Information System (INIS)

    Carter, G.W.

    1979-01-01

    Techniques and equipment are described which are used for video recordings of the single- and two-phase fluid flow tests conducted with the PKL Spool Piece Measurement System designed by Lawrence Livermore Laboratory and EG and G Inc. The instrumented spool piece provides valuable information on what would happen in pressurized water reactor emergency coolant loops should an accident or rupture result in loss of fluid. The complete closed-circuit television video system, including rod lens, light supply, and associated spool mounting fixtures, is discussed in detail. Photographic examples of test flows taken during actual spool piece system operation are shown

  15. Composition: 3 Piano Pieces

    DEFF Research Database (Denmark)

    Bergstrøm-Nielsen, Carl

    2017-01-01

    3 Piano Pieces is a collection of open composition to be realised by an improvising pianist. See more about my composition practise in the entry "Composition - General Introduction".......3 Piano Pieces is a collection of open composition to be realised by an improvising pianist. See more about my composition practise in the entry "Composition - General Introduction"....

  16. Ultrabright and efficient single-photon generation based on nitrogen-vacancy centres in nanodiamonds on a solid immersion lens

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, Tim; Gaedeke, Friedemann; Banholzer, Moritz Julian; Benson, Oliver, E-mail: tim.schroeder@physik.hu-berlin.de [Humboldt-Universitaet zu Berlin, Institut fuer Physik, AG Nano Optics Newtonstrasse 15, 12489 Berlin (Germany)

    2011-05-15

    Single photons are fundamental elements for quantum information technologies such as quantum cryptography, quantum information storage and optical quantum computing. Colour centres in diamond have proven to be stable single-photon sources and thus essential components for reliable and integrated quantum information technology. A key requirement for such applications is a large photon flux and a high efficiency. Paying tribute to various attempts to maximize the single-photon flux, we show that collection efficiencies of photons from colour centres can be increased with a rather simple experimental setup. To do so, we spin-coated nanodiamonds containing single nitrogen-vacancy (N-V) colour centres on the flat surface of a ZrO{sub 2} solid immersion lens. We found stable single-photon count rates of up to 853 kcts s{sup -1} at saturation under continuous wave excitation while having access to more than 100 defect centres with count rates from 400 to 500 kcts s{sup -1}. For a blinking defect centre, we found count rates up to 2.4 Mcts s{sup -1} for time intervals of several tens of seconds. It seems to be a general feature that very high rates are accompanied by blinking behaviour. The overall collection efficiency of our setup of up to 4.2% is the highest yet reported for N-V defect centres in diamond. Under pulsed excitation of a stable emitter of 10 MHz, 2.2% of all pulses caused a click on the detector adding to 221 kcts s{sup -1} thus, opening the way towards diamond-based on-demand single-photon sources for quantum applications.

  17. The effect of pipecol angles for the magnetic electron lens on the aberration coefficients

    International Nuclear Information System (INIS)

    Al-Khshab, A. M.; Al-Khshab, A. H.

    1997-01-01

    The symmetric mag etic objective lens of great importance for the electronic microscopes intended for hi g resolution. Such lens is determined, not only by its geometries structure and shape parameters, but also by the influence of the variation of the pole piece angles. the results show that the Objective lens having the pole piece angle of 55 a has a considerable effect on the electron optical Properties. When this pole piece is appropriately and highly saturated, the lens possesses low spherical and chromatic aberration coefficients. This hind of pole piece lens leads to more favourable design than other lenses. (authors). 14 refs., 7 figs.1 table

  18. RETURNED FOOT EXTERIOR CHORD BROOCHES MADE OF A SINGLE METAL PIECE (TYPE ALMGREN 158 RECENTLY DISCOVERED IN THE WESTERN PLAIN OF ROMANIA.

    Directory of Open Access Journals (Sweden)

    Vitalie Bârcă

    2014-07-01

    Full Text Available This study, without aiming at exhaustiveness, attempts, based on returned foot exterior chord brooches made of a single metal pieces (type Almgren 158 discovered in 2010 following the rescue archaeological excavations performed as a result of the construction of the Arad-Timişoara Highway, respectively section Arad-Seceani, in a series of Sarmatian graves of the cemetery investigated at Hunedoara Timișană, Șagu commune, Arad county, to analyse the brooches in this type discovered in the western territories of Romania.The author examines the four specimens at Hunedoara Timișană within a broader context and concludes that similar brooches in both the Barbarian and Roman environments, where they are imports, date mainly to the chronological interval comprised between the last two decades of the 2nd c. – early 4th c. AD (stages C1a-C2.The analysis of the graves in the cemetery showed that the graves where returned foot exterior chord brooches were found date sometime in the chronological interval comprised between the end of the 2nd c. AD and the third quarter of the 3rd c. AD. Moreover, the author notes that the distribution area of this brooch type is mainly the Barbarian world of German origin (the Przeworsk culture environment or that in constant contact with the latter. Based on the analysis of the distribution area of the Almgren 158 type brooches it was concluded they originate in the Przeworsk culture environment from where they disseminated in the neighbouring south and south-east cultural environments. Last but not least, the author reaches the conclusion that brooches of the type were assumed by the Sarmatians in the Pannonian Plain from the German populations (most likely the Vandals living in the northern vicinity of the area they inhabited. Another conclusion is that such returned foot exterior chord brooches are lacking from the north and north-west Pontic areas, including the Chernyakhov area. Finally, the author argues that

  19. Temperature characterization of a radiating gas layer using digital-single-lens-reflex-camera-based two-color ratio pyrometry.

    Science.gov (United States)

    Deep, Sneh; Krishna, Yedhu; Jagadeesh, Gopalan

    2017-10-20

    The two-color ratio pyrometry technique using a digital single-lens reflex camera has been used to measure the time-averaged and path-integrated temperature distribution in the radiating shock layer in a high-enthalpy flow. A 70 mm diameter cylindrical body with a 70 mm long spike was placed in a hypersonic shock tunnel, and the region behind the shock layer was investigated. The systematic error due to contributions from line emissions was corrected by monitoring the emission spectrum from this region using a spectrometer. The relative contributions due to line emissions on R, G, and B channels of the camera were 7.4%, 2.2%, and 0.4%, respectively. The temperature contours obtained clearly distinguished regions of highest temperature. The maximum absolute temperature obtained in the experiment was ∼2920  K±55  K, which was 20% lower than the stagnation temperature. This lower value is expected due to line-of-sight integration, time averaging, and losses in the flow. Strategies to overcome these limitations are also suggested in the paper.

  20. Kerr-lens mode-locked Ti:Sapphire laser pumped by a single laser diode

    Science.gov (United States)

    Kopylov, D. A.; Esaulkov, M. N.; Kuritsyn, I. I.; Mavritskiy, A. O.; Perminov, B. E.; Konyashchenko, A. V.; Murzina, T. V.; Maydykovskiy, A. I.

    2018-04-01

    The performance of a Ti:sapphire laser pumped by a single 461 nm laser diode is presented for both the continuous-wave and the mode-locked regimes of operation. We introduce a simple astigmatism correction scheme for the laser diode beam consisting of two cylindrical lenses affecting the pump beam along the fast axis of the laser diode, which provides the mode-matching between the nearly square-shaped pump beam and the cavity mode. The resulting efficiency of the suggested Ti:Sapphire oscillator pumped by such a laser diode is analyzed for the Ti:sapphire crystals of 3 mm, 5 mm and 10 mm in length. We demonstrate that such a system provides the generation of ultrashort pulses up to 15 fs in duration with the repetition rate of 87 MHz, the average power being 170 mW.

  1. Sigtuna Think Piece 8

    African Journals Online (AJOL)

    exploring how participatory social learning research may strengthen agency and reflexivity (development of capabilities) in response to socio-ecological conditions. Introduction: Thinking about Climate Change Critically in Context. This think piece emerged from a slow engagement with the topic of climate change and its.

  2. Preventing falls in older multifocal glasses wearers by providing single-lens distance glasses: the protocol for the VISIBLE randomised controlled trial

    Directory of Open Access Journals (Sweden)

    Lee Bonsan B

    2009-03-01

    Full Text Available Abstract Background Recent research has shown that wearing multifocal glasses increases the risk of trips and falls in older people. The aim of this study is to determine whether the provision of single-lens distance glasses to older multifocal glasses wearers, with recommendations for wearing them for walking and outdoor activities, can prevent falls. We will also measure the effect of the intervention on health status, lifestyle activities and fear of falling, as well as the extent of adherence to the program. Methods/Design Approximately 580 older people who are regular wearers of multifocal glasses people will be recruited. Participants will be randomly allocated to either an intervention group (provision of single lens glasses, with counselling and advice about appropriate use or a control group (usual care. The primary outcome measure will be falls (measured with 13 monthly calendars. Secondary measures will be quality of life, falls efficacy, physical activity levels and adverse events. Discussions The study will determine the impact of providing single-lens glasses, with advice about appropriate use, on preventing falls in older regular wearers of multifocal glasses. This pragmatic intervention, if found to be effective, will guide practitioners with regard to recommending appropriate glasses for minimising the risk of falls in older people. Trial Registration The protocol for this study was registered with the Clinical Trials.gov Protocol Registration System on June 7th 2006 (#350855.

  3. Magnetic lens apparatus for use in high-resolution scanning electron microscopes and lithographic processes

    Science.gov (United States)

    Crewe, Albert V.

    2000-01-01

    Disclosed are lens apparatus in which a beam of charged particlesis brought to a focus by means of a magnetic field, the lens being situated behind the target position. In illustrative embodiments, a lens apparatus is employed in a scanning electron microscopeas the sole lens for high-resolution focusing of an electron beam, and in particular, an electron beam having an accelerating voltage of from about 10 to about 30,000 V. In one embodiment, the lens apparatus comprises an electrically-conducting coil arranged around the axis of the beam and a magnetic pole piece extending along the axis of the beam at least within the space surrounded by the coil. In other embodiments, the lens apparatus comprises a magnetic dipole or virtual magnetic monopole fabricated from a variety of materials, including permanent magnets, superconducting coils, and magnetizable spheres and needles contained within an energy-conducting coil. Multiple-array lens apparatus are also disclosed for simultaneous and/or consecutive imaging of multiple images on single or multiple specimens. The invention further provides apparatus, methods, and devices useful in focusing charged particle beams for lithographic processes.

  4. Wire inhomogeneity detector having a core with opposing pole pieces and guide pieces adjacent the opposing pole pieces

    International Nuclear Information System (INIS)

    Gibson, G.H.; Smits, R.G.; Eberhard, P.H.

    1989-01-01

    This patent describes a wire inhomogeneity detector assembly for detecting changes in the conductive properties of a wire as the wire is passed therethrough. It comprises: a coil assembly through which a wire containing conductive material is adapted to be pressed in a direction substantially perpendicular to a longitudinal axis of the coil assembly. The coil assembly comprising a single ferrite core having a pair of opposing pole pieces between which are an associated conductive wire to be tested is adapted to be passed, each of the pole pieces having a coil wound therearound. The coil assembly including a guide-block consisting of a pair of guide pieces mounted adjacent to ends of the opposing pole pieces for guiding an associated conductive wire between the pole pieces and for reducing stray magnetic field lines. The guide pieces being positioned closely adjacent an associated conductive wire passing therebetween; an impedance bridge adjusted to an null balance point operatively connected to the coil assembly which measures the impedance of the coil assembly and is unbalanced by changes in eddy currents generated in the coil assembly; and a filter detector alarm assembly operatively connected to an output of the impedance bridge. The filter detector alarm assembly including an input bandpass filter detector alarm assembly including an input bandpass filter operatively connected to a differential comparator, the output of which triggers an alarm

  5. Reliability of power profiles measured on NIMO TR1504 (Lambda-X) and effects of lens decentration for single vision, bifocal and multifocal contact lenses.

    Science.gov (United States)

    Kim, Eon; Bakaraju, Ravi C; Ehrmann, Klaus

    2016-01-01

    To evaluate the repeatability of power profiles measured on NIMO TR1504 (Lambda-X, Belgium) and investigate the effects of lens decentration on the power profiles for single vision (SV), bifocal (BF) and multifocal (MF) contact lenses. Accuracy of the sphere power was evaluated using single vision BK-7 calibration glass lenses of six minus and six plus powers. Three SV and four BF/MF contact lenses - three lenses each, were measured five times to calculate the coefficients of repeatability (COR) of the instrument. The COR was computed for each chord position, lens design, prescription power and operator. One lens from each type was measured with a deliberate decentration up to ±0.5mm in 0.1mm steps. For all lenses, the COR varied across different regions of the half-chord position. In general, SV lenses showed lower COR compared to the BF/MF group lenses. There were no noticeable trends of COR between prescription powers for SV and BF/MF lenses. The shape of the power profiles was not affected when lenses were deliberately decentered for all SV and PureVision MF lenses. However, for Acuvue BF lenses, the peak to trough amplitude of the power profiles flattened up to 1.00D. The COR across the half-chord of the optic zone diameter was mostly within clinical relevance except for the central 0.5mm half-chord position. COR were dependent on the lens type, whereby BF/MF group produced higher COR than SV lenses. The effects of deliberate decentration on the shape of power profiles were pronounced for lenses where the profiles had sharp transitions of power. Copyright © 2015 Spanish General Council of Optometry. Published by Elsevier Espana. All rights reserved.

  6. Probing the negative permittivity perfect lens at optical frequencies using near-field optics and single molecule detection

    NARCIS (Netherlands)

    Moerland, R.J.; van Hulst, N.F.; Gersen, H.; Kuipers, L.

    2005-01-01

    Recently, the existence of a perfect lens has been predicted, made of an artificial material that has a negative electric permittivity and a negative magnetic permeability. For optical frequencies a poormans version is predicted to exist in the sub-wavelength limit. Then, only the permittivity has

  7. Piece of the sun

    CERN Document Server

    Wayne, Teddy

    2015-01-01

    Our rapidly industrialising world has an insatiable hunger for energy, and conventional sources are struggling to meet demand. Oil is running out, coal is damaging our climate, many nations are abandoning nuclear, yet solar, wind and water will never be a complete replacement. The solution, says Daniel Clery in this deeply researched and revelatory book, is to be found in the original energy source: the Sun itself. There, at its centre, the fusion of 630 million tonnes of hydrogen every second generates an unfathomable amount of energy. By replicating even a tiny piece of the Sun's power

  8. Nonlinear optical refraction of Al2O3 single crystal doping with nickel nanoparticles measured by the Kerr-lens autocorrelation technique

    International Nuclear Information System (INIS)

    Yu, Xiangxiang; Wang, Yuhua; Wang, Yumei

    2014-01-01

    The nonlinear refraction of a nickel doped α-Al 2 O 3 single crystal was measured with a 800 nm pulse using the Kerr-lens autocorrelation technique. The sample was fabricated by ion implantation using a metal vapor vacuum arc ion source. The value of the nonlinear refractive index, n 2 , of the sample was determined to be 7.9 × 10 −16 cm 2 W −1 . The mechanisms of nonlinear refraction of the bulk material and the nanoparticles have been discussed through the UV–vis spectrum and supercontinuum spectra. (paper)

  9. One piece reactor removal

    International Nuclear Information System (INIS)

    Chia, Wei-Min; Wang, Song-Feng

    1993-01-01

    The strategy of Taiwan Research Reactor Renewal plan is to remove the old reactor block with One Piece Reactor Removal (OPRR) method for installing a new research reactor in original building. In this paper, the engineering design of each transportation works including the work method, the major equipments, the design policy and design criteria is described and discussed. In addition, to ensure the reactor block is safety transported for storage and to guarantee the integrity of reactor base mat is maintained for new reactor, operation safety is drawn special attention, particularly under seismic condition, to warrant safe operation of OPRR. ALARA principle and Below Regulatory Concern (BRC) practice were also incorporated in the planning to minimize the collective dose and the total amount of radioactive wastes. All these activities are introduced in this paper. (J.P.N.)

  10. Objective lens

    Science.gov (United States)

    Olczak, Eugene G. (Inventor)

    2011-01-01

    An objective lens and a method for using same. The objective lens has a first end, a second end, and a plurality of optical elements. The optical elements are positioned between the first end and the second end and are at least substantially symmetric about a plane centered between the first end and the second end.

  11. The Up-to-14-Year Survival and Complication Burden of 256 TiUnite Implants Supporting One-Piece Cast Abutment/Metal-Ceramic Implant-Supported Single Crowns.

    Science.gov (United States)

    Walton, Terry R

    To assess the estimated cumulative survival (ECS) and explore the technical and biologic complications of 256 TiUnite implants (Nobel Biocare) supporting one-piece cast abutment/metal-ceramic implant-supported single crowns (ISCs) in situ for up to 14 years. A prospective sequentially recruited cohort of 207 patients received 256 metal-ceramic ISCs on TiUnite implants between 2001 and 2014. All but 24 patients with 27 crowns were clinically evaluated between January 2014 and April 2015 in conjunction with or in addition to their tailored maintenance program. Radiographs were obtained, and any previously recorded treatments associated with the crowns were tabulated. The ECS and standard errors were calculated with the life table actuarial method and Greenwood's formula, respectively. The log rank test was applied to assess differences between anterior and posterior crowns. Complication incidence, severity, and economic burden, measured in time/cost accounting units (TAUs), were tallied and compared descriptively. Independent groups were compared with the Mann-Whitney U test and related groups with the Wilcoxon Signed Rank Test. The mean clinical service time of the crowns was 5.61 years (44 ≥ 10 years). The 14-year ECS was 95.95% ± 3.20% with no significant difference between anterior and posterior prostheses. Only seven implants lost marginal bone ≥ one thread from the time of crown insertion. There were 30 nonterminal complications (16 biologic, 14 mechanical). The associated economic burden was low (n = 35 TAUs). High gold-alloy one-piece cast abutment/metal-ceramic ISCs on TiUnite implants exhibited excellent longevity and few complications over 14 years.

  12. Vitrectorhexis and lens aspiration with posterior chamber intraocular lens implantation in spherophakia.

    Science.gov (United States)

    Al-Haddad, Christiane; Khatib, Lama

    2012-07-01

    We describe a technique that uses the vitrector to perform successful lens aspiration and posterior chamber intraocular lens (IOL) implantation in children with spherophakia and anterior lens subluxation. After an anterior chamber maintainer is placed, the ocutome is introduced through a limbal incision to perform a circular vitrectorhexis to avoid excessive manipulation of the unstable lens followed by gentle cortex aspiration. A foldable IOL is injected into the sulcus (3-piece IOL) or bag (1-piece IOL) if the capsule is sufficiently stable. Through a pars plana incision, the ocutome is then used to perform a posterior capsulotomy to prevent late posterior capsule opacification. In our patient, sulcus IOL placement was more stable than in-the-bag placement. Neither author has a financial or proprietary interest in any material or method mentioned. Copyright © 2012 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  13. Prospective Comparison of One-Piece and Three-Piece Tecnis Aspheric Intraocular Lenses: 1-year Stability and its Effect on Visual Function.

    Science.gov (United States)

    Miyata, Kazunori; Kataoka, Yasushi; Matsunaga, Jiro; Honbo, Masato; Minami, Keiichiro

    2015-09-01

    To compare the stability and visual function of one-piece hydrophobic intraocular lens (IOL) (ZCB00, Abbot Medical Optics) and a three-piece hydrophobic IOL (ZA9003, Abbot Medical Optics) after cataract surgery. Eighteen eyes of 18 patients with the one-piece IOL and 20 eyes of 20 patients with the three-piece IOL who underwent cataract surgery were evaluated prospectively on best corrected distance visual acuity, postoperative refractive error, IOL decentration and tilt, anterior chamber depth (ACD), spherical aberration and contrast sensitivity. Measurements were performed 1 week and 1, 3, 6 and 12 months postoperatively. The postoperative outcomes were compared between the two groups. In the one-piece group, a hyperopic refractive error (p piece group. There were no significant differences in BCVA, IOL tilt, spherical aberration or contrast sensitivity. The stability of the one-piece IOL was greater than that of the three-piece IOL. The postoperative ACD and refractive error demonstrated that an anteriorly offset haptic in the one-piece IOL allowed incremental fixation to the posterior capsule.

  14. Protecting Fundamental (Social) Rights through the Lens of the EU Single Market: the Quest for a More 'Holistic Approach'

    NARCIS (Netherlands)

    de Vries, S.A.

    2016-01-01

    In this article, four trajectories will be followed with a view to further developing the linkages that exist between the EU Single Market and fundamental (social) rights and to examining to what extent the EU Single Market, apart from putting constraints on the realization of social rights, offers

  15. Lens Model

    DEFF Research Database (Denmark)

    Nash, Ulrik William

    2014-01-01

    Firms consist of people who make decisions to achieve goals. How do these people develop the expectations which underpin the choices they make? The lens model provides one answer to this question. It was developed by cognitive psychologist Egon Brunswik (1952) to illustrate his theory...

  16. One-piece modified gasket seal technique.

    Science.gov (United States)

    Wessell, Aaron; Singh, Ameet; Litvack, Zachary

    2013-10-01

    Objectives Review the effectiveness of a modified gasket seal technique utilizing a porous high-density polyethylene plate/rectus sheath fascia construct without fat grafting for primary closure of anterior defects following endoscopic skull base surgery. Design Retrospective review (2011-2012). Setting Single academic medical center. Methods A retrospective review of five patients who underwent expanded endoscopic endonasal surgery for various pathologies (two craniopharyngiomas, two tuberculum meningiomas, and one planum meningioma) was performed. Skull base closure was performed using a one-piece modified gasket seal technique. Primary outcome measures included postoperative cerebrospinal fluid (CSF) leaks and donor site morbidity. Results There were no postoperative CSF leaks. Two patients experienced aseptic meningitis treated with a 14-day course of steroids. Two patients experienced new postoperative chronic/recurrent sinusitis treated with oral antibiotics and topical nasal therapy. There was no donor site morbidity such as infection, hematoma, or hernias. Conclusions The one-piece modified gasket-seal closure is a safe and effective method for reconstruction of endonasal defects of the anterior skull base. Rectus sheath fascia is an appropriate dural substitute for free tissue grafting with low donor site morbidity. The construction of the one-piece graft significantly decreases operative time and lowers the learning curve for multilayered closure.

  17. Bilateral intraocular lens subluxation secondary to haptic angulation.

    Science.gov (United States)

    Moreno-Montañés, Javier; Fernández-Hortelano, Ana; Caire, Josemaría

    2008-04-01

    An 82-year-old man had uneventful phacoemulsification with bilateral implantation of a hydrophilic acrylic, single-piece intraocular lens (IOL) (ACR6D SE, Laboratoires Cornéal). Five years later, simultaneous and bilateral IOL subluxations occurred. In both eyes, the subluxation was situated on the side of one haptic that had moved forward (temporal area in the right eye and superior area in the left eye). In the right eye, the haptic-capsular bag was entrapped by the pupil and produced endothelial damage. A transscleral suture was placed over and under the subluxated haptic through the anterior and posterior capsules to capture the haptic. The haptic was then sutured to the sclera. No postoperative complications developed. We hypothesize that 10-degree angulated and broad haptic junctions can lead to zonular damage and IOL subluxation.

  18. Forensic Analysis of a Contact Lens in a Murder Case.

    Science.gov (United States)

    Zwerling, Charles S

    2016-03-01

    Contact lenses have had rare relevance in trials and/or investigations. After 5 years of burial, orbital remnants were retrieved from an exhumed body and subsequently identified as a key piece of material evidence in a murder trial. The exhumed case materials were evaluated under laboratory conditions and were determined to be contact lens remnants. Contact lens fracture and burial simulation studies were performed to provide additional corroboration of the physical findings of the exhumed contact lens remnants. This material evidence was instrumental in providing factual proof refuting the defendant's testimony in the murder trial. A brief history of contact lens composition and use is provided for understanding the methods and observational results. This forensic case study represents the first published documentation of a contact lens from an exhumed body being used in a murder investigation and establishes an operational procedure for future forensic contact lens examinations. © 2016 American Academy of Forensic Sciences.

  19. RETAINED STONE PIECE IN ANTERIOR CHAMBER

    Directory of Open Access Journals (Sweden)

    ZvornicaninJasmin, Nadarevic-VodencarevicAmra

    2015-04-01

    Full Text Available ABSTRACT We read with interest the article by Surekha et al. regarding the retained stone piece in anterior chamber. Similar to the results of previous studies, the authors found that delayed intraocular foreign body (IOFB management can result in good visual outcome without an apparent increased risk of endophthalmitis or other deleterious side effects. However, the authors failed to explain the exact reason for the diminution of vision in patients left eye. It is unclear what the uncorrected visual acuity was and what kind of correction was used, more precisely type and amount of cylinder, given the presence of the corneal opacity. Since the size of the IOFB is approximately 4x4x1mm, significant irido-corneal angle changes resulting in intraocular pressure raise and optic nerve head damage can be expected. Traumatic glaucoma following open globe injury can occur in 2.7 to 19% of cases, with several risk factors associated with glaucoma development (advanced age, poor visual acuity at presentation,perforating rather than penetrating ocular injury,lens injury, presence of vitreous hemorrhage and presence of an IOFB. Earlier reportsof latetraumaticoptic neuropathy onset, even after several years, indicate that this possibility cannot be completely ruled out too. Therefore, repeated intraocular pressure measurements, gonioscopy, pupillary reaction assessment, together with through posterior segment examination including visual field and optical coherence tomography examinations can be useful in determining the possible optic nerve damage as one of the possible reasons for visual acuity reduction. The authors did not suggest any operative treatment at this time. However, it should bear in mind that the inert anterior chamber IOFB could be a risk factor for non-infectious endophthalmitis development even after many years. Also, long term retained anterior chamber foreign body leads to permanent endothelial cell loss and can even result in a corneal

  20. pyLIMA: An Open-source Package for Microlensing Modeling. I. Presentation of the Software and Analysis of Single-lens Models

    Science.gov (United States)

    Bachelet, E.; Norbury, M.; Bozza, V.; Street, R.

    2017-11-01

    Microlensing is a unique tool, capable of detecting the “cold” planets between ˜1 and 10 au from their host stars and even unbound “free-floating” planets. This regime has been poorly sampled to date owing to the limitations of alternative planet-finding methods, but a watershed in discoveries is anticipated in the near future thanks to the planned microlensing surveys of WFIRST-AFTA and Euclid's Extended Mission. Of the many challenges inherent in these missions, the modeling of microlensing events will be of primary importance, yet it is often time-consuming, complex, and perceived as a daunting barrier to participation in the field. The large scale of future survey data products will require thorough but efficient modeling software, but, unlike other areas of exoplanet research, microlensing currently lacks a publicly available, well-documented package to conduct this type of analysis. We present version 1.0 of the python Lightcurve Identification and Microlensing Analysis (pyLIMA). This software is written in Python and uses existing packages as much as possible to make it widely accessible. In this paper, we describe the overall architecture of the software and the core modules for modeling single-lens events. To verify the performance of this software, we use it to model both real data sets from events published in the literature and generated test data produced using pyLIMA's simulation module. The results demonstrate that pyLIMA is an efficient tool for microlensing modeling. We will expand pyLIMA to consider more complex phenomena in the following papers.

  1. Comparison of immediately loaded flapless-placed one-piece implants and flapped-placed conventionally loaded two-piece implants, both fitted with all-ceramic single crowns, 
in the posterior mandible: 3-year results from 
a randomised controlled pilot trial.

    Science.gov (United States)

    Bömicke, Wolfgang; Gabbert, Olaf; Koob, Andreas; Krisam, Johannes; Rammelsberg, Peter

    To compare outcomes for immediately loaded one-piece implants (OPI), placed flapless, and conventionally loaded two-piece implants (TPI), placed after two-stage flapped surgery. Thirty-eight participants were randomised to receive either one OPI (19 participants, OPI group) or one TPI (19 participants, TPI group) inserted in the posterior mandible with a torque of at least 35 Ncm according to a parallel group design. OPI were immediately loaded with non-occluding temporary crowns. After 3 months, TPI were exposed and implants in both groups were occlusally loaded with zirconia crowns. Outcome measures were implant failure, prosthesis failure, any complication and changes of probing pocket depth (PPD), plaque index (PI), gingiva index (GI), and peri-implant marginal bone level, recorded by unblinded assessors. Three years after occlusal loading, three participants dropped out from the TPI group. There were no statistically significant differences between the groups with regard to participants with implant failure (OPI group 1/19; TPI group 0/16; difference in proportions (DIP), -5.3%; 95% confidence interval (CI) -15.3 to 4.8; P = 1.000), prosthesis failure (OPI group 3/19, TPI group 5/16; DIP, 15.5%; 95% CI -12.6 to 43.5; P = 0.424), any complication (OPI group 6/19, TPI group 5/16; DIP, -0.3%; 95% CI -31.2 to 30.5; P = 1.000), or changes of PPD (P =0.174), PI (P = 0.222), or GI (P = 0.415). Veneer chipping accounted for most prosthesis failures and complications. On average OPI and TPI lost 1.34 mm and 0.67 mm of marginal bone, respectively, the difference between groups being statistically significant (mean difference, 0.66 mm; 95% CI -0.02 to 1.34; P = 0.024) in favour of TPI implants. Both implant procedures might be viable in the short term, but statistically significantly more bone loss might be indicative of future problems with OPI. Because of the high incidence of chipping, veneered zirconia crowns cannot be recommended

  2. Contact lens in keratoconus

    Directory of Open Access Journals (Sweden)

    Varsha M Rathi

    2013-01-01

    Full Text Available Contact lenses are required for the visual improvement in patients with keratoconus. Various contact lens options, such as rigid gas permeable (RGP lenses, soft and soft toric lenses, piggy back contact lenses (PBCL, hybrid lenses and scleral lenses are availble. This article discusses about selection of a lens depending on the type of keratoconus and the fitting philosophies of various contact lenses including the starting trial lens. A Medline search was carried out for articles in the English language with the keywords keratoconus and various contact lenses such as Rose k lens, RGP lens, hybrid lens, scleral lens and PBCL.

  3. Contact lens in keratoconus

    Science.gov (United States)

    Rathi, Varsha M; Mandathara, Preeji S; Dumpati, Srikanth

    2013-01-01

    Contact lenses are required for the visual improvement in patients with keratoconus. Various contact lens options, such as rigid gas permeable (RGP) lenses, soft and soft toric lenses, piggy back contact lenses (PBCL), hybrid lenses and scleral lenses are availble. This article discusses about selection of a lens depending on the type of keratoconus and the fitting philosophies of various contact lenses including the starting trial lens. A Medline search was carried out for articles in the English language with the keywords keratoconus and various contact lenses such as Rose k lens, RGP lens, hybrid lens, scleral lens and PBCL. PMID:23925325

  4. Planar optical correlators integrated with binary optical lens.

    Science.gov (United States)

    Xu, Ping; Hong, Chunquan; Cheng, Guanxiao; Zhou, Liang; Sun, Zhilong

    2015-03-09

    Planar optical correlators (POCs) can achieve smaller volume of optical system and hence have important applications to identify dynamic targets in complex scenarios. POCs, however, generally have serious astigmatism and optical efficiency loss introduced by its refractive lens with a zigzag optical beam. To conquer the disadvantages of POCs, we propose a type of binary optical planar-integrated optical correlator. The correlator incorporates two pieces of reflective binary optical lens as Fourier transform lens and one spatial light modulator as a programmable filter. The off-axis aberrations commonly occurred in POCs can be corrected by using reflective binary optical lens instead of refractive lens. As a model of hybrid numerical-optical correlator using optoelectronic interface, the proposal is helpful to improve the integration and flexibility and robustness of POCs.

  5. Characterizing Lenses and Lensed Stars of High-magnification Single-lens Gravitational Microlensing Events with Lenses Passing over Source Stars

    DEFF Research Database (Denmark)

    Choi, J.-Y; Park, S.-Y; Han, C.

    2012-01-01

    -source effect. For seven events, we measure the Einstein radii and the lens-source relative proper motions. Among them, five events are found to have Einstein radii of less than 0.2 mas, making the lenses very low mass star or brown dwarf candidates. For MOA-2011-BLG-274, especially, the small Einstein radius...

  6. One Piece Immediately Loaded Implants Versus 1 Piece or 2 Pieces Delayed: 3 Years Outcome.

    Science.gov (United States)

    Duda, Mariusz; Matalon, Shlomo; Lewinstein, Israel; Harel, Noga; Block, Jonathan; Ormianer, Zeev

    2016-02-01

    To compare time-dependent outcome of immediately loaded 1-piece (1P) implants with delayed loaded 1P and 2-piece (2P) implants. A cohort of 33 patients divided into 3 groups: group A, 13 patients, 49 immediately placed and loaded 1P implants; group B, 11 patients, immediately placed and delayed loaded 1P implants; and group C, 10 patients, 39 2P implants delayed placed and loaded in a two-stage procedure. Marginal bone loss (MBL) was analyzed using x-ray radiography every 6 months, 1 year, and 3 years. A statistically significant mean MBL was observed between baseline, 6 months, 1 year, and 3 years in all groups. There was no statistical significant difference in MBL between immediate and delayed loaded 1P implants. MBL around mandibular implants was lower compared with maxillary implants. 2P implants showed less MBL compared with 1P implants in both maxilla and mandible. There was no statistical difference in MBL between immediate and delayed loaded 1P implants. Immediate loaded implants show more MBL in maxilla.

  7. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... lens because they can be purchased over-the-counter or on the Internet," says Thomas Steinemann, MD, ... Halloween Safety Colored Contact Lens Facts Over-the-Counter Costume Contacts May Contain Chemicals Harmful to Eyes ...

  8. Multiple glass pieces in paranasal sinuses

    Directory of Open Access Journals (Sweden)

    Syed Ahmed Mohiuddin

    2011-01-01

    Full Text Available Here, a case has been reported of a road traffic accident with multiple glass pieces arranged in an unusual pattern in the left maxillary sinus, ethmoid sinus, nasopharynx and medial side of the orbit, as seen in the radiographs. Combined surgical approach through the existing wound and endoscopic surgery was successfully used to remove nearly all the glass pieces.

  9. Field calculations, single-particle tracking, and beam dynamics with space charge in the electron lens for the Fermilab Integrable Optics Test Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Noll, Daniel [Goethe Univ., Frankfurt (Germany); Stancari, Giulio [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2015-11-17

    An electron lens is planned for the Fermilab Integrable Optics Test Accelerator as a nonlinear element for integrable dynamics, as an electron cooler, and as an electron trap to study space-charge compensation in rings. We present the main design principles and constraints for nonlinear integrable optics. A magnetic configuration of the solenoids and of the toroidal section is laid out. Singleparticle tracking is used to optimize the electron path. Electron beam dynamics at high intensity is calculated with a particle-in-cell code to estimate current limits, profile distortions, and the effects on the circulating beam. In the conclusions, we summarize the main findings and list directions for further work.

  10. One-piece implants: placement timing, surgical technique, loading protocol, and marginal bone loss.

    Science.gov (United States)

    Prithviraj, D R; Gupta, Vikas; Muley, Ninad; Sandhu, Pushpinder

    2013-04-01

    Osseointegration being an accepted and well-documented concept, attention is now directed towards simplification of the mechanical design of implants and towards achieving biomechanical success. The aim of this literature review is to provide an overview of the one-piece implant, with its advantages and disadvantages over a conventional two-piece implant. The PubMed database was searched in the English language using the keywords one-piece implant, single-piece implant, single-stage implant surgery, and two-piece implant. Articles were selected on the basis of whether they had sufficient information related to placement timing, surgical procedure used, loading protocol, follow-up periods, marginal bone loss, and implant success rates of one-piece implants. For inclusion, a study group must have had a minimum of 30 one-piece implants followed for at least 1 year. Nineteen articles were subjected to the selection criteria. Out of 19 clinical trials only 11 met the selection criteria. Five parameters were taken into consideration for studying one-piece implants: placement timing, surgical technique, loading protocol, marginal bone loss, and implant survival rate. The data from the identified studies were tabulated according to these parameters and discussed. Delayed placement of one-piece implants is more commonly practiced than extraction and immediate placement. Most surgeons prefer surgeries using flaps as compared to flapless surgeries, and in most cases, one-piece implants were loaded immediately. Limited literature reveals both positive and negative results regarding the effect of a one-piece implant system on surrounding hard and soft tissues. © 2012 by the American College of Prosthodontists.

  11. Model Checking in Bits and Pieces

    Directory of Open Access Journals (Sweden)

    Kedar S. Namjoshi

    2013-09-01

    Full Text Available Fully automated verification of concurrent programs is a difficult problem, primarily because of state explosion: the exponential growth of a program state space with the number of its concurrently active components. It is natural to apply a divide and conquer strategy to ameliorate state explosion, by analyzing only a single component at a time. We show that this strategy leads to the notion of a "split" invariant, an assertion which is globally inductive, while being structured as the conjunction of a number of local, per-component invariants. This formulation is closely connected to the classical Owicki-Gries method and to Rely-Guarantee reasoning. We show how the division of an invariant into a number of pieces with limited scope makes it possible to apply new, localized forms of symmetry and abstraction to drastically simplify its computation. Split invariance also has interesting connections to parametric verification. A quantified invariant for a parametric system is a split invariant for every instance. We show how it is possible, in some cases, to invert this connection, and to automatically generalize from a split invariant for a small instance of a system to a quantified invariant which holds for the entire family of instances.

  12. One-piece versus two-piece orbitozygomatic craniotomy: quantitative and qualitative considerations.

    Science.gov (United States)

    Tanriover, Necmettin; Ulm, Arthur J; Rhoton, Albert L; Kawashima, Masatou; Yoshioka, Nobutaka; Lewis, Stephen B

    2006-04-01

    The orbitozygomatic (OZ) craniotomy minimizes brain retraction and improves cranial base exposure by providing a multidirectional view, increased operative angles and working space. The two main variations of the approach include the one-piece and the two-piece types. The microsurgical anatomy of the one- and two-piece OZ craniotomies are presented with the goal of comparing the extent of orbital roof removal between these two craniotomies and the effect of orbital roof removal on operative exposure. Ten two-piece and 11 one-piece OZ craniotomies were performed in a stepwise manner simulating the approaches on formalin fixed specimens. The orbital surface area removed above the frontozygomatic suture extending medially over the orbital roof was measured from each bone flap. The two-sided unpaired t test using STATA 7.0 software was used to compare the amount of orbital roof removed using the two approaches. The two-piece OZ craniotomy allowed for the removal of a larger portion of the roof and lateral wall of the orbit than the one-piece. The total orbitotomy, including the orbital roof plus the part of the lateral wall above the frontozygomatic suture, had an average surface area of 996 +/- 229 mm for the two piece and 372 +/- 103 mm for the one-piece. The orbital roof made up 27 +/- 18% of the orbital osteotomy for the one-piece craniotomies and 67 +/- 10% of the osteotomy for the two-piece craniotomies (P piece OZ craniotomy allows for more extensive orbital roof removal and better visualization of the basal frontal lobe. Therefore, the two-piece may result in a lower incidence of enophtalmus and poor cosmetic outcomes, particularly if the remaining orbital roof must be removed piecemeal during the one-piece OZ craniotomy in order to obtain satisfactory exposure.

  13. Last piece of ATLAS takes the plunge

    CERN Document Server

    2008-01-01

    On Friday 29 February the second small wheel was lowered 100 metres underground into the ATLAS cavern in front of a captivated audience. Although called the "small wheels" they are small in name only - each wheel is 9.3 metres in diameter and weighs 100 tonnes including the massive shielding elements. This piece completes ATLAS’ muon spectrometer, which has the ability to accurately track particles to the width of a human hair. The first piece of ATLAS was installed in 2003 and, five years later, this small wheel is the final large piece of the detector to take the subterranean voyage to its final resting place.

  14. REFRACTIVE NEUTRON LENS

    OpenAIRE

    Petrov, P. V.; Kolchevsky, N. N.

    2013-01-01

    Compound concave refractive lenses are used for focusing neutron beam. Investigations of spectral and focusing properties of a refractive neutron lens are presented. Resolution of the imaging system on the base of refractive neutron lenses depends on material properties and parameters of neutron source. Model of refractive neutron lens are proposed. Results of calculation diffraction resolution and focal depth of refractive neutron lens are discussed.

  15. Contact lens in keratoconus

    OpenAIRE

    Rathi, Varsha M; Mandathara, Preeji S; Dumpati, Srikanth

    2013-01-01

    Contact lenses are required for the visual improvement in patients with keratoconus. Various contact lens options, such as rigid gas permeable (RGP) lenses, soft and soft toric lenses, piggy back contact lenses (PBCL), hybrid lenses and scleral lenses are availble. This article discusses about selection of a lens depending on the type of keratoconus and the fitting philosophies of various contact lenses including the starting trial lens. A Medline search was carried out for articles in the En...

  16. 29 CFR 1910.177 - Servicing multi-piece and single piece rim wheels.

    Science.gov (United States)

    2010-07-01

    ..., trailers, buses and off-road machines. It does not apply to the servicing of rim wheels used on automobiles... components shall not be interchanged except as provided in the charts or in the applicable rim manual. (2...

  17. Anterior segment parameters: comparison of 1-piece and 3-piece acrylic foldable intraocular lenses.

    Science.gov (United States)

    Behrouz, Mahmoud Jabbarvand; Kheirkhah, Ahmad; Hashemian, Hesam; Nazari, Rahman

    2010-10-01

    To compare anterior segment parameters between 1-piece and 3-piece acrylic foldable intraocular lenses (IOLs). Farabi Eye Hospital, Tehran, Iran. Prospective randomized comparative case series. Eyes scheduled for phacoemulsification were randomized into 2 equal groups to receive a 1-piece (AcrySof SA60AT) or 3-piece (AcrySof MA60AC) foldable acrylic IOL. Scheimpflug imaging (Pentacam) was used to measure anterior segment parameters, including anterior chamber depth (ACD), anterior chamber angle (ACA), and anterior chamber volume (ACV), preoperatively and 1 week and 3 months postoperatively. The study evaluated 125 eyes (123 patients). There was a statistically significant postoperative increase in ACD, ACA, and ACV at 1 week and 3 months in both IOL groups. Although the mean ACD was significantly higher in the 3-piece group at 1 week, there was no significant between-group difference in ACD, ACA, or ACV at 3 months. There was no significant change in anterior segment parameters from 1 week to 3 months in the 1-piece group; however, the 3-piece group had statistically significant decreases in ACD, ACA, and ACV. Refraction remained stable throughout the follow-up in the 1-piece group but showed a significant myopic shift from 1 week to 3 months in the 3-piece group. After phacoemulsification, the 1-piece acrylic foldable IOL showed little axial movement and provided stable refraction throughout the follow-up. The 3-piece IOL had significant forward movement and led to a myopic shift within 3 months postoperatively. Results indicate that spectacles can be prescribed earlier in eyes with a 1-piece IOL. Copyright © 2010 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  18. Last piece of the puzzle for ATLAS

    CERN Multimedia

    Clare Ryan

    At around 15.40 on Friday 29th February the ATLAS collaboration cracked open the champagne as the second of the small wheels was lowered into the cavern. Each of ATLAS' small wheels are 9.3 metres in diameter and weigh 100 tonnes including the massive shielding elements. They are the final parts of ATLAS' muon spectrometer. The first piece of ATLAS was installed in 2003 and since then many detector elements have journeyed down the 100 metre shaft into the ATLAS underground cavern. This last piece completes this gigantic puzzle.

  19. Non-compliance with lens care and maintenance in diabetic contact lens wearers.

    Science.gov (United States)

    O'Donnell, Clare; Efron, Nathan

    2004-11-01

    We hypothesize that diabetic contact lens wearers may represent a special group displaying higher levels of compliance with their lens care regimens as a result of learned behaviour relating to maintenance of their diabetic condition. To test this hypothesis, a prospective, single centre, controlled, masked study was performed whereby 29 diabetic contact lens patients and 29 non-diabetic control subjects were issued with disposable hydrogel contact lenses and a multipurpose lens care regimen. All participants were given identical instruction on lens care and maintenance. Compliance levels were assessed at a 12-month aftercare appointment by demonstration and questionnaire. Twenty-four different aspects of compliance were scored, 12 by observation and 12 by questionnaire report, of which only two showed a significant difference between the diabetic and control groups. Although the combined population of contact lens wearers was generally compliant, there were examples of non-compliance in both groups. Neither the duration of diabetes nor the degree of metabolic control appeared to have a significant effect on compliance. The results suggest that eye care practitioners cannot assume that diabetic patients will be more compliant with contact lens care and maintenance than non-diabetic patients.

  20. Investigation of the stability of one-piece acrylic intraocular lenses in cataract surgery and in combined vitrectomy surgery.

    Science.gov (United States)

    Iwase, T; Sugiyama, K

    2006-12-01

    To compare the degrees of intraocular lens (IOL) movement between eyes that received a one-piece acrylic IOL and those that received a three-piece acrylic IOL after cataract surgery, and also among eyes that received a one-piece acrylic IOL after a combined vitrectomy surgery for cataract. In the first study, we report on 50 patients who were implanted with a one-piece acrylic IOL in one eye and a three-piece acrylic IOL in the contralateral eye for senile cataract. In the second study, we report on 50 patients who were implanted with a one-piece acrylic IOL in combined vitrectomy surgery for cataract and retinal diseases. The degree of IOL decentration and tilt, and anterior chamber depth (ACD) were measured using Scheimpflug video photography at 1 week, 1 month, 3 months and 6 months after surgery in both the studies. The postoperative refractive status was also examined. The mean decentration and tilt showed no marked changes during the follow-up in eyes with either IOL implanted, and no marked differences were noted in either study throughout the follow-up. The ACD did not change after surgery with one-piece IOL implantation, for either the cataract surgery group or the combined surgery group, except for 1 week after surgery in eyes requiring gas tamponade. In contrast, marked shallowing in ACD was observed in the three-piece group after cataract surgery. The spherical equivalent did not change markedly in either study. The one-piece acrylic IOL was stable in the capsular bag, both horizontally and vertically, after cataract surgery, and also after combined surgery.

  1. Sealed One Piece Battery Having A Prism Shape Container

    Science.gov (United States)

    Verhoog, Roelof; Barbotin, Jean-Loup

    2000-03-28

    A sealed one-piece battery having a prism-shaped container including: a tank consisting of a single plastic material, a member fixed and sealed to the tank and to partitions on the side of the tank opposite the transverse wall to seal the tank, two flanges fixed and sealed to longitudinal walls defining flow compartments for a heat-conducting fluid, and two tubes on the transverse wall of the tank forming an inlet and an outlet for fluid common to the compartments.

  2. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... One Use Facts About Colored Contacts and Halloween Safety Colored Contact Lens Facts Over-the-Counter Costume ... new application of artificial intelligence shows whether a patient’s eyes point to high blood pressure or risk ...

  3. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... be purchased over-the-counter or on the Internet," says Thomas Steinemann, MD, professor of ophthalmology at ... ask for a prescription. There is no such thing as a "one size fits all" contact lens. ...

  4. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... had not been properly fitted by an eye care professional, the lenses stuck to my eye like ... lenses do not require the same level of care or consideration as a standard contact lens because ...

  5. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... sell contacts without a prescription are breaking the law, and may be fined $11,000 per violation. " ... wear any kind of contact lens. In Butler's case, the lenses caused an infection and left her ...

  6. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... One Use Facts About Colored Contacts and Halloween Safety Colored Contact Lens Facts Over-the-Counter Costume ... Costume Contact Lenses Can Ruin Vision Eye Makeup Safety In fact, it is illegal to sell colored ...

  7. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... with Colored Contact Lenses Julian: Teenager Blinded In One Eye By Non-Prescription Contact Lens Laura: Vision ... Robyn: Blurry Vision and Daily Eye Drops After One Use Facts About Colored Contacts and Halloween Safety ...

  8. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... One Use Facts About Colored Contacts and Halloween Safety Colored Contact Lens Facts Over-the-Counter Costume ... Academy Jobs at the Academy Financial Relationships with Industry Medical Disclaimer Privacy Policy Terms of Service For ...

  9. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... in a pair of colored contact lenses, Laura Butler of Parkersburg, W.Va., had "extreme pain in ... to wear any kind of contact lens. In Butler's case, the lenses caused an infection and left ...

  10. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... One Use Facts About Colored Contacts and Halloween Safety Colored Contact Lens Facts Over-the-Counter Costume ... use of colored contact lenses , from the U.S. Food and Drug Administration (FDA). Are the colored lenses ...

  11. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... an impulsive buy from a souvenir shop, but 10 hours after she first put in a pair ... Prescription Contact Lens Laura: Vision Loss After Just 10 Hours Robyn: Blurry Vision and Daily Eye Drops ...

  12. bubble chamber lens

    CERN Multimedia

    Before the days of electronic detectors, visual techniques were used to detect particles, using detectors such as spark chambers and bubble chambers. This plexiglass lens was used to focus the image of tracks so they could be photographed.

  13. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... Contact Lens Facts Over-the-Counter Costume Contacts May Contain Chemicals Harmful to Eyes Four Ways Over- ... without a prescription are breaking the law, and may be fined $11,000 per violation. "Many of ...

  14. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... not require the same level of care or consideration as a standard contact lens because they can ... sell contacts without a prescription are breaking the law, and may be fined $11,000 per violation. " ...

  15. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... One Use Facts About Colored Contacts and Halloween Safety Colored Contact Lens Facts Over-the-Counter Costume ... an ophthalmologist — an eye medical doctor — who will measure each eye and talk to you about proper ...

  16. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... prescription. Follow the contact lens care directions for cleaning, disinfecting, and wearing the lenses. Never share contact ... with Industry Medical Disclaimer Privacy Policy Terms of Service For Advertisers For Media Ophthalmology Job Center © American ...

  17. Performance evaluation of aluminium test piece against ...

    African Journals Online (AJOL)

    Image processing with Catphan 700 uses the automated Quality Assurance software restricted to only Digital Imaging and Communications in Medicine images. For this reason, an aluminium (Al) test piece device was fabricated for image processing in different image format for spatial resolution measurement.

  18. One-Piece Force-Transducer Body

    Science.gov (United States)

    Meyer, R. A.

    1986-01-01

    Rugged unit designed to operate in severe environment. Forcetransducer body designed for measurement of loads on specimens tested in hydrogen gas at temperatures up to 2,000 degree F (1,090 degree C). Body has symmetrical radial-shear-beam configuration and machined in one piece from bar stock.

  19. Viscous froth lens

    Science.gov (United States)

    Green, T. E.; Bramley, A.; Lue, L.; Grassia, P.

    2006-11-01

    Microscale models of foam structure traditionally incorporate a balance between bubble pressures and surface tension forces associated with curvature of bubble films. In particular, models for flowing foam microrheology have assumed this balance is maintained under the action of some externally imposed motion. Recently, however, a dynamic model for foam structure has been proposed, the viscous froth model, which balances the net effect of bubble pressures and surface tension to viscous dissipation forces: this permits the description of fast-flowing foam. This contribution examines the behavior of the viscous froth model when applied to a paradigm problem with a particularly simple geometry: namely, a two-dimensional bubble “lens.” The lens consists of a channel partly filled by a bubble (known as the “lens bubble”) which contacts one channel wall. An additional film (known as the “spanning film”) connects to this bubble spanning the distance from the opposite channel wall. This simple structure can be set in motion and deformed out of equilibrium by applying a pressure across the spanning film: a rich dynamical behavior results. Solutions for the lens structure steadily propagating along the channel can be computed by the viscous froth model. Perturbation solutions are obtained in the limit of a lens structure with weak applied pressures, while numerical solutions are available for higher pressures. These steadily propagating solutions suggest that small lenses move faster than large ones, while both small and large lens bubbles are quite resistant to deformation, at least for weak applied back pressures. As the applied back pressure grows, the structure with the small lens bubble remains relatively stiff, while that with the large lens bubble becomes much more compliant. However, with even further increases in the applied back pressure, a critical pressure appears to exist for which the steady-state structure loses stability and unsteady

  20. Product management of making large pieces through Rapid Prototyping PolyJet® technology

    Science.gov (United States)

    Belgiu, G.; Cărăuşu, C.; Şerban, D.; Turc, C. G.

    2017-08-01

    The rapid prototyping process has already become a classic manufacturing process for parts and assemblies, either polymeric or metal parts. Besides the well-known advantages and disadvantages of the process, the use of 3D printers has a great inconvenience: the overall dimensions of the parts are limited. Obviously, there is a possibility to purchase a larger (and more expensive) 3D printer, but there are always larger pieces to be manufactured. One solution to this problem is the splitting of parts into several components that can be manufactured. The component parts can then be assembled in a single piece by known methods such as welding, gluing, screwing, etc. This paper shows our experience in making large pieces on the Strarasys® Objet24 printer, pieces larger than the tray sizes. The results obtained are valid for any 3D printer using the PolyJet® process.

  1. Rotman lens for mm-wavelengths

    Science.gov (United States)

    Hall, Leonard T.; Hansen, Hedley J.; Abbott, Derek

    2002-11-01

    The 77 GHz band has been reserved for intelligent cruise control in luxury cars and some public transport services in America and the United Kingdom. The Rotman lens offers a cheap and compact means to extend the single beam systems generally used, to fully functional beam staring arrangements. Rotman lenses have been built for microwave frequencies with limited success. The flexibility of microstrip transmission lines and the advent of fast accurate simulation packages allow practical Rotman lenses to be designed at mm-wavelengths. This paper discusses the limitations of the conventional design approach and predicts the performance of a new Rotman lens designed at 77 GHz.

  2. Surface dimpling on rotating work piece using rotation cutting tool

    Science.gov (United States)

    Bhapkar, Rohit Arun; Larsen, Eric Richard

    2015-03-31

    A combined method of machining and applying a surface texture to a work piece and a tool assembly that is capable of machining and applying a surface texture to a work piece are disclosed. The disclosed method includes machining portions of an outer or inner surface of a work piece. The method also includes rotating the work piece in front of a rotating cutting tool and engaging the outer surface of the work piece with the rotating cutting tool to cut dimples in the outer surface of the work piece. The disclosed tool assembly includes a rotating cutting tool coupled to an end of a rotational machining device, such as a lathe. The same tool assembly can be used to both machine the work piece and apply a surface texture to the work piece without unloading the work piece from the tool assembly.

  3. Novel Technique to Overcome the Nonavailability of a Long Needle 9-0 Polypropylene Suture for Sutured Scleral Fixation of the Posterior Chamber Intraocular Lens Using a Single Fisherman’s Knot

    Directory of Open Access Journals (Sweden)

    Yong Un Shin

    2017-01-01

    Full Text Available Purpose. To describe a method to overcome the nonavailability of a long needle 9-0 polypropylene suture for sutured scleral fixation of the posterior chamber intraocular lens (PC-IOL using a single fisherman’s knot (SFK. Methods. First, a 10-0 polypropylene suture was passed from the sclera to the ciliary sulcus using a long needle. A 9-0 suture was tied to the unpassed portion of the 10-0 suture with an SFK. We pulled the 10-0 suture to pass the SFK through the sclera, and then we cut the knot and removed the 10-0 suture. IOL fixation with 9-0 sutures used the conventional techniques used for sutured scleral-fixated IOL. Preoperative and postoperative visual acuity, corneal astigmatism, and endothelial cell count and intraoperative/postoperative complications were evaluated. Results. An SFK joining the two sutures was passed through the sclera without breakage or slippage. A total of 35 eyes from 35 patients who underwent sutured scleral fixation of the IOL. An intraoperative complication (minor intraocular hemorrhage was recorded in four cases. Knot exposure, IOL dislocation, subluxation, and retinal detachment were not observed. Conclusions. The SFK offers the opportunity to use 9-0 sutures for the long-term safety and may not require the surgeon to learn any new technique.

  4. Novel Technique to Overcome the Nonavailability of a Long Needle 9-0 Polypropylene Suture for Sutured Scleral Fixation of the Posterior Chamber Intraocular Lens Using a Single Fisherman's Knot.

    Science.gov (United States)

    Shin, Yong Un; Seong, Mincheol; Cho, Hee Yoon; Kang, Min Ho

    2017-01-01

    To describe a method to overcome the nonavailability of a long needle 9-0 polypropylene suture for sutured scleral fixation of the posterior chamber intraocular lens (PC-IOL) using a single fisherman's knot (SFK). First, a 10-0 polypropylene suture was passed from the sclera to the ciliary sulcus using a long needle. A 9-0 suture was tied to the unpassed portion of the 10-0 suture with an SFK. We pulled the 10-0 suture to pass the SFK through the sclera, and then we cut the knot and removed the 10-0 suture. IOL fixation with 9-0 sutures used the conventional techniques used for sutured scleral-fixated IOL. Preoperative and postoperative visual acuity, corneal astigmatism, and endothelial cell count and intraoperative/postoperative complications were evaluated. An SFK joining the two sutures was passed through the sclera without breakage or slippage. A total of 35 eyes from 35 patients who underwent sutured scleral fixation of the IOL. An intraoperative complication (minor intraocular hemorrhage) was recorded in four cases. Knot exposure, IOL dislocation, subluxation, and retinal detachment were not observed. The SFK offers the opportunity to use 9-0 sutures for the long-term safety and may not require the surgeon to learn any new technique.

  5. Oxygen transport through soft contact lens and cornea: Lens characterization and metabolic modeling

    Science.gov (United States)

    Chhabra, Mahendra

    The human cornea requires oxygen to sustain metabolic processes critical for its normal functioning. Any restriction to corneal oxygen supply from the external environment (e.g., by wearing a low oxygen-permeability contact lens) can lead to hypoxia, which may cause corneal edema (swelling), limbal hyperemia, neovascularization, and corneal acidosis. The need for adequate oxygen to the cornea is a major driving force for research and development of hypertransmissible soft contact lenses (SCLs). Currently, there is no standard technique for measuring oxygen permeability (Dk) of hypertransmissible silicone-hydrogel SCLs. In this work, an electrochemistry-based polarographic apparatus was designed, built, and operated to measure oxygen permeability in hypertransmissible SCLs. Unlike conventional methods where a range of lens thickness is needed for determining oxygen permeabilities of SCLs, this apparatus requires only a single lens thickness. The single-lens permeameter provides a reliable, efficient, and economic tool for measuring oxygen permeabilities of commercial hypertransmissible SCLs. The single-lens permeameter measures not only the product Dk, but, following modification, it measures separately diffusivity, D, and solubility, k, of oxygen in hypertransmissible SCLs. These properties are critical for designing better lens materials that ensure sufficient oxygen supply to the cornea. Metabolism of oxygen in the cornea is influenced by contact-lens-induced hypoxia, diseases such as diabetes, surgery, and drug treatment, Thus, estimation of the in-vivo corneal oxygen consumption rate is essential for gauging adequate oxygen supply to the cornea. Therefore, we have developed an unsteady-state reactive-diffusion model for the cornea-contact-lens system to determine in-vivo human corneal oxygen-consumption rate. Finally, a metabolic model was developed to determine the relation between contact-lens oxygen transmissibility (Dk/L) and corneal oxygen deficiency. A

  6. Contrast enhancement of mail piece images

    Science.gov (United States)

    Shin, Yong-Chul; Sridhar, Ramalingam; Demjanenko, Victor; Palumbo, Paul W.; Hull, Jonathan J.

    1992-08-01

    A New approach to contrast enhancement of mail piece images is presented. The contrast enhancement is used as a preprocessing step in the real-time address block location (RT-ABL) system. The RT-ABL system processes a stream of mail piece images and locates destination address blocks. Most of the mail pieces (classified into letters) show high contrast between background and foreground. As an extreme case, however, the seasonal greeting cards usually use colored envelopes which results in reduced contrast osured by an error rate by using a linear distributed associative memory (DAM). The DAM is trained to recognize the spectra of three classes of images: with high, medium, and low OCR error rates. The DAM is not forced to make a classification every time. It is allowed to reject as unknown a spectrum presented that does not closely resemble any that has been stored in the DAM. The DAM was fairly accurate with noisy images but conservative (i.e., rejected several text images as unknowns) when there was little ground and foreground degradations without affecting the nondegraded images. This approach provides local enhancement which adapts to local features. In order to simplify the computation of A and (sigma) , dynamic programming technique is used. Implementation details, performance, and the results on test images are presented in this paper.

  7. Development of an in vivo visual robot system with a magnetic anchoring mechanism and a lens cleaning mechanism for laparoendoscopic single-site surgery (LESS).

    Science.gov (United States)

    Feng, Haibo; Dong, Dinghui; Ma, Tengfei; Zhuang, Jinlei; Fu, Yili; Lv, Yi; Li, Liyi

    2017-12-01

    Surgical robot systems which can significantly improve surgical procedures have been widely used in laparoendoscopic single-site surgery (LESS). For a relative complex surgical procedure, the development of an in vivo visual robot system for LESS can effectively improve the visualization for surgical robot systems. In this work, an in vivo visual robot system with a new mechanism for LESS was investigated. A finite element method (FEM) analysis was carried out to ensure the safety of the in vivo visual robot during the movement, which was the most important concern for surgical purposes. A master-slave control strategy was adopted, in which the control model was established by off-line experiments. The in vivo visual robot system was verified by using a phantom box. The experiment results show that the robot system can successfully realize the expected functionalities and meet the demands of LESS. The experiment results indicate that the in vivo visual robot with high manipulability has great potential in clinical application. Copyright © 2017 John Wiley & Sons, Ltd.

  8. A catoptric lens

    International Nuclear Information System (INIS)

    Rambauske, W.R.

    1973-01-01

    The invention relates to a catoptric lens for combining energies transmitted by several sources such as lasers; said lens comprising mirrors, the reflective surfaces of which have their focuses spaced from a common axis of symmetry. By means of these reflecting surfaces, which are generated by the nutation of portions of quadratic conics about the axis of symmetry, it is possible to focus the energy emmited by several lasers at the focus of the exit-mirror reflecting surface. This can be applied to thermonuclear fusion [fr

  9. Candidate gravitational microlensing events for future direct lens imaging

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, C. B.; Gould, A.; Gaudi, B. S. [Department of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Park, H.; Han, C. [Department of Physics, Institute for Astrophysics, Chungbuk National University, Cheongju 371-763 (Korea, Republic of); Sumi, T.; Koshimoto, N. [Department of Earth and Space Science, Osaka University, Osaka 560-0043 (Japan); Udalski, A. [Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa (Poland); Tsapras, Y. [Las Cumbres Observatory Global Telescope Network, 6740 Cortona Drive, Suite 102, Goleta, CA 93117 (United States); Bozza, V. [Department of Physics, University of Salerno, I-84084 Fisciano (Italy); Abe, F.; Fukunaga, D.; Itow, Y.; Masuda, K. [Solar-Terrestrial Environment Laboratory, Nagoya University, Nagoya 464-8601 (Japan); Bennett, D. P. [Department of Physics, University of Notre Dame, 225 Nieuwland Science Hall, Notre Dame, IN 46556-5670 (United States); Bond, I. A.; Ling, C. H. [Institute of Information and Mathematical Sciences, Massey University, Private Bag 102-904, North Shore Mail Centre, Auckland 0745 (New Zealand); Botzler, C. S.; Freeman, M. [Department of Physics, University of Auckland, Private Bag 92-019, Auckland 1001 (New Zealand); Fukui, A. [School of Chemical and Physical Sciences, Victoria University, Wellington 6140 (New Zealand); Collaboration: MOA Collaboration; OGLE Collaboration; μFUN Collaboration; RoboNet Collaboration; and others

    2014-10-10

    The mass of the lenses giving rise to Galactic microlensing events can be constrained by measuring the relative lens-source proper motion and lens flux. The flux of the lens can be separated from that of the source, companions to the source, and unrelated nearby stars with high-resolution images taken when the lens and source are spatially resolved. For typical ground-based adaptive optics (AO) or space-based observations, this requires either inordinately long time baselines or high relative proper motions. We provide a list of microlensing events toward the Galactic bulge with high relative lens-source proper motion that are therefore good candidates for constraining the lens mass with future high-resolution imaging. We investigate all events from 2004 to 2013 that display detectable finite-source effects, a feature that allows us to measure the proper motion. In total, we present 20 events with μ ≳ 8 mas yr{sup –1}. Of these, 14 were culled from previous analyses while 6 are new, including OGLE-2004-BLG-368, MOA-2005-BLG-36, OGLE-2012-BLG-0211, OGLE-2012-BLG-0456, MOA-2012-BLG-532, and MOA-2013-BLG-029. In ≲12 yr from the time of each event the lens and source of each event will be sufficiently separated for ground-based telescopes with AO systems or space telescopes to resolve each component and further characterize the lens system. Furthermore, for the most recent events, comparison of the lens flux estimates from images taken immediately to those estimated from images taken when the lens and source are resolved can be used to empirically check the robustness of the single-epoch method currently being used to estimate lens masses for many events.

  10. An adjustable electron achromat for cathode lens microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Tromp, R.M., E-mail: rtromp@us.ibm.com [IBM T.J. Watson Research Center, 1101 Kitchawan Road, Yorktown Heights, NY 10598 (United States); Leiden Institute of Physics, Kamerlingh Onnes Laboratory, Niels Bohrweg 2, 2333 CA Leiden (Netherlands)

    2015-12-15

    Chromatic aberration correction in light optics began with the invention of a two-color-corrected achromatic crown/flint lens doublet by Chester Moore Hall in 1730. Such color correction is necessary because any single glass shows dispersion (i.e. its index of refraction changes with wavelength), which can be counteracted by combining different glasses with different dispersions. In cathode lens microscopes (such as Photo Electron Emission Microscopy – PEEM) we encounter a similar situation, where the chromatic aberration coefficient of the cathode lens shows strong dispersion, i.e. depends (non-linearly) on the energy with which the electrons leave the sample. Here I show how a cathode lens in combination with an electron mirror can be configured as an adjustable electron achromat. The lens/mirror combination can be corrected at two electron energies by balancing the settings of the electron mirror against the settings of the cathode lens. The achromat can be adjusted to deliver optimum performance, depending on the requirements of a specific experiment. Going beyond the achromat, an apochromat would improve resolution and transmission by a very significant margin. I discuss the requirements and outlook for such a system, which for now remains a wish waiting for fulfilment. - Highlights: • The properties of cathode objective lens plus electron mirror are discussed. • In analogy with light-optical achromats, cathode lens plus mirror can be configured as an electron achromat. • Unlike light optics, the electron achromat can be adjusted to best fulfill experimental requirements.

  11. Quadrupole magnetic lens

    International Nuclear Information System (INIS)

    Piskunov, V.A.

    1981-01-01

    The following connection of windings of electromagnet is suggested for simplification of the design of qUadrupole magnetic lens intended for use in radiotechnical and electron-optical devices. The mentioned windings are connected with each other by a bridge scheme and the variable resistors are switched in its diagonals in the lens containing four electromagnet with windings connected with two variable resistors the mobile contacts of which are connected with a direct current source. Current redistribution between left windings and right windings takes place at shift of mobile contact of variable resistor, and current redistribution between upper and low coils of electromagnets takes place at shifting mobile contact of the other variable resistor. In this case smooth and independent electron-optical misalignment of lens by two mutually perpendicular directions proceeds. Use of the given design of the lens in the oscillograph permits to use printing assembly for alignment plate and to reduce the number of connections at the expense of decreasing the number of resistors

  12. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... prescription. There is no such thing as a "one size fits all" contact lens. Lenses that are not properly fitted may scratch the eye or cause blood vessels to grow into the cornea. Even if you have perfect vision, you need to get an eye exam and a prescription ...

  13. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... Ophthalmologist Patient Stories Español Eye Health / News Halloween Hazard: The Hidden Dangers of Buying Decorative Contact Lenses ... One Use Facts About Colored Contacts and Halloween Safety Colored Contact Lens Facts Over-the-Counter Costume ...

  14. The Lens of Chemistry

    Science.gov (United States)

    Thalos, Mariam

    2013-01-01

    Chemistry possesses a distinctive theoretical lens--a distinctive set of theoretical concerns regarding the dynamics and transformations of a perplexing variety of organic and nonorganic substances--to which it must be faithful. Even if it is true that chemical facts bear a special (reductive) relationship to physical facts, nonetheless it will…

  15. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... wear any kind of contact lens. In Butler's case, the lenses caused an infection and left her with a corneal ... A recent article from U.S. News and World Report explains what ophthalmologists are and how they can ...

  16. bubble chamber lens

    CERN Multimedia

    Was used in a PS experiment. Before the days of electronic detectors, visual techniques were used to detect particles, using detectors such as spark chambers and bubble chambers. This plexiglass lens was used to focus the image of tracks so they could be photographed.

  17. Thermal Lens Microscope

    Science.gov (United States)

    Uchiyama, Kenji; Hibara, Akihide; Kimura, Hiroko; Sawada, Tsuguo; Kitamori, Takehiko

    2000-09-01

    We developed a novel laser microscope based on the thermal lens effect induced by a coaxial beam comprised of excitation and probe beams. The signal generation mechanism was confirmed to be an authentic thermal lens effect from the measurement of signal and phase dependences on optical configurations between the sample and the probe beam focus, and therefore, the thermal lens effect theory could be applied. Two-point spatial resolution was determined by the spot size of the excitation beam, not by the thermal diffusion length. Sensitivity was quite high, and the detection ability, evaluated using a submicron microparticle containing dye molecules, was 0.8 zmol/μm2, hence a distribution image of trace chemical species could be obtained quantitatively. In addition, analytes are not restricted to fluorescent species, therefore, the thermal lens microscope is a promising analytical microscope. A two-dimensional image of a histamine molecule distribution, which was produced in mast cells at the femtomole level in a human nasal mucous polyp, was obtained.

  18. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... an Ophthalmologist Patient Stories Español Eye Health / News Halloween Hazard: The Hidden Dangers of Buying Decorative Contact ... After One Use Facts About Colored Contacts and Halloween Safety Colored Contact Lens Facts Over-the-Counter ...

  19. One-Piece Leak-Proof Battery

    Science.gov (United States)

    Verhoog, Roelof

    1999-03-23

    The casing of a leak-proof one-piece battery is made of a material comprising a mixture of at least a matrix based on polypropylene and an alloy of a polyamide and a polypropylene. The ratio of the matrix to the alloy is in the range 0.5 to 6 by weight. The alloy forms elongate arborescent inclusions in the matrix such that, on average, the largest dimension of a segment of the arborescence is at least twenty times the smallest dimension of the segment.

  20. Retaining Device For One-Piece Battery

    Science.gov (United States)

    Gilabert, Claude; Leturque, Michel; Verhoog, Roclof

    2000-08-01

    The present invention consists of a device for retaining a one-piece battery with a prismatic casing having two longitudinal walls and two transverse walls. The device contains two plates applied to respective transverse walls and at least one cinching mechanism for the plates consisting of at least one flat strip closed on itself surrounding the longitudinal walls and the transverse walls are provided with the plates. The device is characterized in that at least one of the plates contains at least one recessed housing and the strip closely follows the shape of the housing.

  1. Developing the Regulatory Utility of the Exposome: Mapping Exposures for Risk Assessment through Lifestage Exposome Snapshots (LEnS).

    Science.gov (United States)

    Shaffer, Rachel M; Smith, Marissa N; Faustman, Elaine M

    2017-08-07

    Exposome-related efforts aim to document the totality of human exposures across the lifecourse. This field has advanced rapidly in recent years but lacks practical application to risk assessment, particularly for children's health. Our objective was to apply the exposome to children's health risk assessment by introducing the concept of Lifestage Exposome Snapshots (LEnS). Case studies are presented to illustrate the value of the framework. The LEnS framework encourages organization of exposome studies based on windows of susceptibility for particular target organ systems. Such analyses will provide information regarding cumulative impacts during specific critical periods of the life course. A logical extension of this framework is that regulatory standards should analyze exposure information by target organ, rather than for a single chemical only or multiple chemicals grouped solely by mechanism of action. The LEnS concept is a practical refinement to the exposome that accounts for total exposures during particular windows of susceptibility in target organ systems. Application of the LEnS framework in risk assessment and regulation will improve protection of children's health by enhancing protection of sensitive developing organ systems that are critical for lifelong health and well-being. https://doi.org/10.1289/EHP1250.

  2. Clinical survey of lens care in contact lens patients.

    Science.gov (United States)

    Ky, W; Scherick, K; Stenson, S

    1998-10-01

    Overall, contact lenses provide a safe and effective modality for vision correction. However, problems do occasionally arise. Up to 80% of contact lens complications can be traced to poor patient compliance with recommended lens care guidelines. We conducted a survey to evaluate the level of patient compliance in specific areas of lens care and maintenance and to assess patient knowledge of basic contact lens information. Patients were asked to complete an anonymous 15 question survey that focused on lens care--specifically the use of contact lens cleaners, methods of disinfection, enzyme treatments, use of rewetting drops, and the frequency of follow-up exams. In addition, the survey included six true/false questions relating to contact lens care and safety. There were a total of 103 participants in the study. Approximately 24% of patients stated they never cleaned their lenses prior to disinfection, and 5% used saline solutions as their primary mode of disinfection. A sizable portion of those surveyed (43% of soft lens wearers and 71% of rigid gas permeable lens wearers) either never used enzyme cleaners or used them less than once a month. Seventy percent of patients either never used rewetting drops or used them less than once a day. Twenty-nine percent of patients consulted their eye care professionals every 2 years and 6% less often than every two years. Six questions assessed patient knowledge of contact lens care safety. Of a possible six out of six correct answers, the mean number of correct responses was 3.74. A sizable proportion of contact lens wearers do not adequately adhere to recommended contact lens care, and many have an inadequate understanding of contact lens care guidelines. Therefore, it is important that practitioners place more emphasis on patient education at the time of initial contact lens fitting and reinforce such instruction during follow-up visits.

  3. The balanced two-string technique for sulcus intraocular lens implantation in the absence of capsular support.

    Science.gov (United States)

    Ibrahim, Hesham A; Sabry, Heba Nabil

    2015-01-01

    Purpose. To describe and explore an alternative approach for sulcus intraocular lens (IOL) implantation in the absence of capsular support. Methods. The commonly available one-piece poly(methyl methacrylate) (PMMA) lens is stabilized in the sulcus by two intraocular horizontal strings of 10/0 polypropylene suture passed through the lens dialing holes in opposite directions to achieve a mechanical balance. The horizontal strings of 10/0 polypropylene work as a rail track for the IOL optics, allowing some side to side lens adjustment even following wound closure. The stability of the IOL was tested in vitro. Six aphakic patients underwent in-sulcus IOL secondary implantation using the balanced two-string technique. Patients were followed up for a minimum of six months. Best spectacle corrected vision was assessed. Lens centration and lens tilt were measured by anterior segment optical coherence tomography (AS-OCT). Results. All patients had successful lens insertion. Best spectacle corrected visual acuity (BSCVA) improved in all patients. Lens decentration ranged between 0.21 mm and 0.9 mm (average 0.53 mm). Lens tilt ranged between 1.2° and 2.8° (average 2.17°). Conclusion. The mechanically balanced two-string technique is an alternative option for sulcus IOL implantation in absence of capsular support, allowing lens centration adjustment with no additional risks.

  4. The Balanced Two-String Technique for Sulcus Intraocular Lens Implantation in the Absence of Capsular Support

    Science.gov (United States)

    Ibrahim, Hesham A.; Sabry, Heba Nabil

    2015-01-01

    Purpose. To describe and explore an alternative approach for sulcus intraocular lens (IOL) implantation in the absence of capsular support. Methods. The commonly available one-piece poly(methyl methacrylate) (PMMA) lens is stabilized in the sulcus by two intraocular horizontal strings of 10/0 polypropylene suture passed through the lens dialing holes in opposite directions to achieve a mechanical balance. The horizontal strings of 10/0 polypropylene work as a rail track for the IOL optics, allowing some side to side lens adjustment even following wound closure. The stability of the IOL was tested in vitro. Six aphakic patients underwent in-sulcus IOL secondary implantation using the balanced two-string technique. Patients were followed up for a minimum of six months. Best spectacle corrected vision was assessed. Lens centration and lens tilt were measured by anterior segment optical coherence tomography (AS-OCT). Results. All patients had successful lens insertion. Best spectacle corrected visual acuity (BSCVA) improved in all patients. Lens decentration ranged between 0.21 mm and 0.9 mm (average 0.53 mm). Lens tilt ranged between 1.2° and 2.8° (average 2.17°). Conclusion. The mechanically balanced two-string technique is an alternative option for sulcus IOL implantation in absence of capsular support, allowing lens centration adjustment with no additional risks. PMID:25722884

  5. The Balanced Two-String Technique for Sulcus Intraocular Lens Implantation in the Absence of Capsular Support

    Directory of Open Access Journals (Sweden)

    Hesham A. Ibrahim

    2015-01-01

    Full Text Available Purpose. To describe and explore an alternative approach for sulcus intraocular lens (IOL implantation in the absence of capsular support. Methods. The commonly available one-piece poly(methyl methacrylate (PMMA lens is stabilized in the sulcus by two intraocular horizontal strings of 10/0 polypropylene suture passed through the lens dialing holes in opposite directions to achieve a mechanical balance. The horizontal strings of 10/0 polypropylene work as a rail track for the IOL optics, allowing some side to side lens adjustment even following wound closure. The stability of the IOL was tested in vitro. Six aphakic patients underwent in-sulcus IOL secondary implantation using the balanced two-string technique. Patients were followed up for a minimum of six months. Best spectacle corrected vision was assessed. Lens centration and lens tilt were measured by anterior segment optical coherence tomography (AS-OCT. Results. All patients had successful lens insertion. Best spectacle corrected visual acuity (BSCVA improved in all patients. Lens decentration ranged between 0.21 mm and 0.9 mm (average 0.53 mm. Lens tilt ranged between 1.2° and 2.8° (average 2.17°. Conclusion. The mechanically balanced two-string technique is an alternative option for sulcus IOL implantation in absence of capsular support, allowing lens centration adjustment with no additional risks.

  6. Note onset deviations as musical piece signatures.

    Science.gov (United States)

    Serrà, Joan; Özaslan, Tan Hakan; Arcos, Josep Lluis

    2013-01-01

    A competent interpretation of a musical composition presents several non-explicit departures from the written score. Timing variations are perhaps the most important ones: they are fundamental for expressive performance and a key ingredient for conferring a human-like quality to machine-based music renditions. However, the nature of such variations is still an open research question, with diverse theories that indicate a multi-dimensional phenomenon. In the present study, we consider event-shift timing variations and show that sequences of note onset deviations are robust and reliable predictors of the musical piece being played, irrespective of the performer. In fact, our results suggest that only a few consecutive onset deviations are already enough to identify a musical composition with statistically significant accuracy. We consider a mid-size collection of commercial recordings of classical guitar pieces and follow a quantitative approach based on the combination of standard statistical tools and machine learning techniques with the semi-automatic estimation of onset deviations. Besides the reported results, we believe that the considered materials and the methodology followed widen the testing ground for studying musical timing and could open new perspectives in related research fields.

  7. Note onset deviations as musical piece signatures.

    Directory of Open Access Journals (Sweden)

    Joan Serrà

    Full Text Available A competent interpretation of a musical composition presents several non-explicit departures from the written score. Timing variations are perhaps the most important ones: they are fundamental for expressive performance and a key ingredient for conferring a human-like quality to machine-based music renditions. However, the nature of such variations is still an open research question, with diverse theories that indicate a multi-dimensional phenomenon. In the present study, we consider event-shift timing variations and show that sequences of note onset deviations are robust and reliable predictors of the musical piece being played, irrespective of the performer. In fact, our results suggest that only a few consecutive onset deviations are already enough to identify a musical composition with statistically significant accuracy. We consider a mid-size collection of commercial recordings of classical guitar pieces and follow a quantitative approach based on the combination of standard statistical tools and machine learning techniques with the semi-automatic estimation of onset deviations. Besides the reported results, we believe that the considered materials and the methodology followed widen the testing ground for studying musical timing and could open new perspectives in related research fields.

  8. Fractal dimension analysis of complexity in Ligeti piano pieces

    Science.gov (United States)

    Bader, Rolf

    2005-04-01

    Fractal correlation dimensional analysis has been performed with whole solo piano pieces by Gyrgy Ligeti at every 50ms interval of the pieces. The resulting curves of development of complexity represented by the fractal dimension showed up a very reasonable correlation with the perceptional density of events during these pieces. The seventh piece of Ligeti's ``Musica ricercata'' was used as a test case. Here, each new part of the piece was followed by an increase of the fractal dimension because of the increase of information at the part changes. The second piece ``Galamb borong,'' number seven of the piano Etudes was used, because Ligeti wrote these Etudes after studying fractal geometry. Although the piece is not fractal in the strict mathematical sense, the overall structure of the psychoacoustic event-density as well as the detailed event development is represented by the fractal dimension plot.

  9. [Correct contact lens hygiene].

    Science.gov (United States)

    Blümle, S; Kaercher, T; Khaireddin, R

    2013-06-01

    Although contact lenses have long been established in ophthalmology, practical aspects of handling contact lenses is becoming increasingly less important in the clinical training as specialist for ophthalmology. Simultaneously, for many reasons injuries due to wearing contact lenses are increasing. In order to correct this discrepancy, information on contact lenses and practical experience with them must be substantially increased from a medical perspective. This review article deals with the most important aspects for prevention of complications, i.e. contact lens hygiene.

  10. A new piece of the puzzle

    CERN Multimedia

    2005-01-01

    The team responsible for the installation of the hadronic calorimeter's central barrel after completion of the assembly work. Assembly of the great ATLAS puzzle continues underground. On 10 December, the final module of the central barrel of the tile hadronic calorimeter was assembled. This piece of the tile calorimeter had already been assembled above ground during a "dress rehearsal" in 2003 (see Bulletin no 46/2003, 10 November 2003). The hadronic calorimeter's two other barrels, the so-called "extended barrels", remain to be assembled with this first central barrel, which now surrounds the electromagnetic calorimeter barrel that was lowered into the cavern at the end of October. At the end of November, the second of the eight barrel toroid coils was also installed.

  11. Two-piece hollow bulb obturator

    Directory of Open Access Journals (Sweden)

    Subramaniam Elangovan

    2011-01-01

    Full Text Available There are various types of obturator fabrication achievable by prosthodontist. Maxillectomy, which is a term used by head and neck surgeons and prosthodontists to describe the partial or total removal of the maxilla in patients suffering from benign or malignant neoplasms is a defect for which to provide an effective obturator is a difficult task for the maxillofacial prosthodontist. Multidisciplinary treatment planning is essential to achieve adequate retention and function for the prosthesis. Speech is often unintelligible as a result of the marked defects in articulation and nasal resonance. This paper describes how to achieve the goal for esthetics and phonetics and also describes the fabrication of a hollow obturator by two piece method, which is simple and maybe used as definitive obturator for maximum comfort of the patient.

  12. On-eye breakage and recovery of mini-scleral contact lens without compromise for the ocular surface.

    Science.gov (United States)

    Macedo-de-Araújo, Rute J; van der Worp, Eef; González-Méijome, José M

    2017-12-13

    To report the on-eye breakage of a mini-scleral contact lens in a healthy cornea after being hit by a speeding object, without causing any severe corneal damage. A 24-year-old Caucasian male involved in a clinical study reported the in situ breakage of a mini-scleral contact lens during motorbike maintenance. The patient reported eye redness and irritation that significantly decreased after all the pieces of the lens were recovered from the eye. Ocular examinations within 48 h showed absence of corneal damage other than superficial punctate keratitis inferiorly and no fragments of the lens were found in the conjunctival sac. The patient was wearing a 15.2 mm mini-scleral lens in a high Dk material. The evolution of rigid materials towards higher Dk values has resulted in a decreased hardness and modulus values, so these materials are more elastic when subjected to mechanical stress, which could be a beneficial aspect in absorbing the energy of an impact before breaking in pieces. This case report shows that ScCL could have a protective effect to the corneal surface from the direct impact of a high-speed object. Mechanical material properties, wide supporting area and post-lens tear volume acted as protective factors helping to absorb and distribute the kinetic energy of the impacting object. Copyright © 2017 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  13. Prolonging contact lens wear and making contact lens wear safer.

    Science.gov (United States)

    Foulks, Gary N

    2006-02-01

    To summarize the present status of safety and efficacy of contact lens wear. Literature review. Ovid Medline searches were performed on records from 1966 through 2005 using keywords: keratitis, contact lens complications, extended-wear contact lenses, and silicone-hydrogel contact lenses. Patients desire comfort, clarity of vision, and prolonged contact lens wear when contact lenses are used to correct refractive error. Practitioners desire patient satisfaction but also require maintenance of the integrity of the eye and no complications that jeopardize vision or health of the eye. Improvements in the oxygen permeability of the contact lens materials, design of the contact lens and its surface, and solutions for the maintenance of the lens have reduced but not eliminated the risks of infection, inflammation, and conjunctival papillary reaction associated with contact lens wear. The lessons of past and recent history suggest that patient education and practitioner participation in the management of contact lens wear continue to be critical factors for patient satisfaction and safety in the extended wear of contact lenses. The availability of highly oxygen permeable contact lenses has increased the tolerance and safety of extended contact lens wear, but patient instruction and education in proper use and care of lenses is required and caution is advised.

  14. Development of high precision and cryogenic lens holders

    Science.gov (United States)

    Reutlinger, A.; Boesz, Anton; Mottaghibonab, A.; Eckert, P.; Dubowy, M.; Gebler, H.; Grupp, F.; Geis, N.; Bode, A.; Katterloher, R.; Bender, R.

    2017-11-01

    The optical system of the Near Infrared Spectrometer and Photometer (NISP) of the EUCLID mission consists mainly of a filter and grism wheel and 4 aspherical lenses with large diameters up to 170 mm. The single lenses require a high precision positioning at the operational temperature of 150 K. An additional design driver represents the CaF2 material of a lens, which is very sensitive wrt brittleness. The technical maturity of the combination of single features such as CaF2, large diameter (and mass), high precision and cryogenic conditions is considered as low. Therefore, a dedicated pre-development program has been launched to design and develop a first prototype of lens holder and to demonstrate the functional performance at representative operational conditions. The 4 lenses are divided into 3x lenses for the Camera Lens Assembly (CaLA) and 1x lens for the Corrector Lens Assembly (CoLA). Each lens is glue mounted onto solid state springs, part of an adaption ring. The adaption ring shall provide protection against vibration loads, high accuracy positioning, as well as quasi load free mounting of the lens under operational conditions. To reduce thermomechanical loads on the lens, the CTE of the adaption ring is adapted to that of the lens. The glue between lens and solid state spring has to withstand high tension loads during vibration. At the operational temperature the deviating CTE between glue and lens/adaption ring introduces shear loads into the glue interface, which are critical, in particular for the fragile CaF2 lens material. For the case of NISP the shear loads are controlled with the glue pad diameter and the glue thickness. In the context of the development activity many technology aspects such as various solid state spring designs, glue selection and glue handling have been investigated. A parametric structural model was developed to derive the specific design feature of each ring, such as spring force, number of springs, eigenfrequency, etc. This

  15. Comparison of Two Intraocular Lens Implantation Techniques in Pediatric Cataract Surgery in Terms of Postoperative Complications

    Directory of Open Access Journals (Sweden)

    Mustafa Erdoğan Cicik

    2018-03-01

    Full Text Available Background: Pediatric cataract surgery differs substantially from adult cataract surgery. Numerous studies have focused on reducing the development of postoperative complications. Aims: To compare two intraocular lens implantation techniques used in pediatric cataract surgery in terms of postoperative complications. Study Design: Case-control study. Methods: Patients who underwent pediatric cataract surgery and intraocular lens implantation between 2008 and 2016 were evaluated in this retrospective study. Patients aged 3-15 years with unilateral or bilateral cataract and without corneal pathology were included in the study. The patients were categorized into the following two groups: those who underwent posterior capsulorhexis and anterior vitrectomy using in-the-bag intraocular lens implantation (group 1 and those who underwent posterior capsulorhexis and intraocular lens implantation with the optic fixed behind the posterior capsulorhexis (group 2. Rates of postoperative visual axis opacification and complications (glaucoma, posterior synechiae, uveitic reaction, and intraocular lens decentration were evaluated in these groups. The implanted intraocular lenses were either monoblock (AcrySof SN60AT intraocular lens, triple-piece (AcrySof MA60BM intraocular lens foldable hydrophobic acrylic lenses, or multifocal lenses (AcrySof IQ ReSTOR. Results: This retrospective study included 52 eyes of 37 patients. Group 1 comprised 26 eyes of 20 patients and group 2 comprised 26 eyes of 17 patients. During the follow-up, visual axis opacification was observed in two patients in group 1 but no patients in group 2. Regarding postoperative complications, there was no uveitic reaction, posterior synechiae, or intraocular lens decentration in either group. There was no significant difference between the groups in terms of the postoperative complications (p>0.05. Conclusion: There was no significant difference between in-the-bag intraocular lens implantation

  16. Two-piece cryopreserved tracheal allotransplantation: an experimental study.

    Science.gov (United States)

    Iyikesici, Tuncel; Tuncozgur, Bulent; Sanli, Maruf; Isik, Ahmet Feridun; Meteroglu, Fatih; Elbeyli, Levent

    2009-10-01

    For successful reconstruction with tracheal allotransplants following long tracheal resections, problems related to the preservation and vascularisation of the tracheal graft have to be solved. In this study, instead of using a long-segment single-piece graft, we used a graft that has been split into two. The aim was to use this graft after cryopreservation in order to ease neo-vascularisation and to maintain tracheal integrity by transplanting it to two separate regions of the dog cervical trachea. This experimental study was conducted in animal laboratories of the medical school on 11 half-blood dogs. The trachea obtained from the first dog was 8 cm in length; it was split into two pieces of 4 cm each and stored in the preservation solution at -80 degrees C for 4 weeks. Following this, the dog was sacrificed. Two 2 cm portions of cervical trachea were excised from the second dog. These parts were then reconstructed with two tracheal grafts of the same length as the cryopreserved ones. Ten dogs that were grouped into five groups of two dogs each underwent the same procedure. The subjects had a bronchoscopic evaluation on the third postoperative week. Anastomosis regions of the test tracheas were resected to be examined histopathologically. Seven subjects were found to have third-degree obstructions during bronchoscopy; two had close to fourth-degree obstructions. In the histopathological examination, contrary to the findings of the bronchoscopies, 75% of the anastomoses had intact epithelium. The cartilage was seen to have well-preserved structural characteristics in all the anastomoses. Twelve anastomoses had moderate, seven mild and one had severe inflammation. All anastomoses had either good or very good level of vascularisation. The integrity of the tracheal epithelium can be maintained with cryopreservation and split anastomosis technique. The cartilage preserves its structural characteristics despite losing its viability, thereby offering an advantage to

  17. Thin wetting film lens-less imaging

    International Nuclear Information System (INIS)

    Allier, C.P.; Poher, V.; Coutard, J.G.; Hiernard, G.; Dinten, J.M.

    2011-01-01

    Lens-less imaging has recently attracted a lot of attention as a compact, easy-to-use method to image or detect biological objects like cells, but failed at detecting micron size objects like bacteria that often do not scatter enough light. In order to detect single bacterium, we have developed a method based on a thin wetting film that produces a micro-lens effect. Compared with previously reported results, a large improvement in signal to noise ratio is obtained due to the presence of a micro-lens on top of each bacterium. In these conditions, standard CMOS sensors are able to detect single bacterium, e.g. E. coli, Bacillus subtilis and Bacillus thuringiensis, with a large signal to noise ratio. This paper presents our sensor optimization to enhance the SNR; improve the detection of sub-micron objects; and increase the imaging FOV, from 4.3 mm 2 to 12 mm 2 to 24 mm 2 , which allows the detection of bacteria contained in 0.5 μl to 4 μl to 10 μl, respectively. (authors)

  18. [Study on quality standards of decoction pieces of salt Alpinia].

    Science.gov (United States)

    Li, Wenbing; Hu, Changjiang; Long, Lanyan; Huang, Qinwan; Xie, Xiuqiong

    2010-12-01

    To establish the quality criteria for decoction pieces of salt Alpinia. Decoction pieces of salt Alpinia were measured with moisture, total ash, acid-insoluble ash, water-extract and volatile oils according to the procedures recorded in the Chinese Pharmacopoeia 2010. The content of Nootkatone was determined by HPLC, and NaCl, by chloridion electrode method. We obtained results of total ash, acid-insoluble ash, water-extract and volatile oils of 10 batches of decoction pieces of salt Alpinia moisture; Meanwhile we set the HPLC and chloridion electrode method. This research established a fine quality standard for decoction pieces of salt Alpinia.

  19. Electrically switchable holographic liquid crystal/polymer Fresnel lens using a Michelson interferometer.

    Science.gov (United States)

    Jashnsaz, Hossein; Mohajerani, Ezeddin; Nemati, Hossein; Razavi, Seyed Hossein; Alidokht, Isa Ahmad

    2011-06-10

    A holographic technique for fabricating an electrically switchable liquid crystal/polymer composite Fresnel lens is reported. A Michelson interferometer is used to produce the required Fresnel pattern, by placing a convex lens into one path of the interferometer. Simplicity of the method and the possibility of fabricating different focal length lenses in a single arrangement are advantages of the method. The performance of the fabricated lens was demonstrated and its electro-optical properties were investigated for its primary focal length.

  20. The last piece of the ring

    CERN Multimedia

    2008-01-01

    In a sequel to the recent success at CMS, the last section of the LHC beam vacuum system was installed in ATLAS on Monday 16 June. The place where experiment and accelerator meet, the completion of the last part of the continuous 27 km beampipe signals how near the LHC is to the circulation of its first beam. Watch the video! The last section of the LHC beampipe being installed in ATLAS.Although a seemingly simple piece of technology in comparison with the complexity of the detectors, the beampipe is a carefully designed and essential part of both the experiments and the LHC. The section of beam pipe that completed the LHC ring on Monday 16 June is about 20 metres from the centre of ATLAS, very close to where the first magnets of the LHC are located. Unlike the central ATLAS beampipe, which is made of beryllium, the final section is made of stainless steel. An aluminium cone surrounds the stainless steel tube with the super slim...

  1. A Heuristic Bioinspired for 8-Piece Puzzle

    Science.gov (United States)

    Machado, M. O.; Fabres, P. A.; Melo, J. C. L.

    2017-10-01

    This paper investigates a mathematical model inspired by nature, and presents a Meta-Heuristic that is efficient in improving the performance of an informed search, when using strategy A * using a General Search Tree as data structure. The work hypothesis suggests that the investigated meta-heuristic is optimal in nature and may be promising in minimizing the computational resources required by an objective-based agent in solving high computational complexity problems (n-part puzzle) as well as In the optimization of objective functions for local search agents. The objective of this work is to describe qualitatively the characteristics and properties of the mathematical model investigated, correlating the main concepts of the A * function with the significant variables of the metaheuristic used. The article shows that the amount of memory required to perform this search when using the metaheuristic is less than using the A * function to evaluate the nodes of a general search tree for the eight-piece puzzle. It is concluded that the meta-heuristic must be parameterized according to the chosen heuristic and the level of the tree that contains the possible solutions to the chosen problem.

  2. Compliance among soft contact lens wearers.

    OpenAIRE

    Kuzman, Tomislav; Barišić Kutija, Marija; Masnec, Sanja; Jandroković, Sonja; Mrazovac, Danijela; Jurišić, Darija; Škegro, Ivan; Kalauz, Miro; Kordić, Rajko

    2014-01-01

    Contact lens compliance is proven to be crucial for preventing lens wear-related complications because of the interdependence of the steps in lens care regime and their influence on lens system microbial contamination. Awareness of the patients' lens handling compliance as well as correct recognition of non-compliant behaviours is the basis for creating more targeted strategies for patient education. The aim of this study was to investigate compliance among soft contact lens (SCL) wearers in ...

  3. Panoramic lens applications revisited

    Science.gov (United States)

    Thibault, Simon

    2008-04-01

    During the last few years, innovative optical design strategies to generate and control image mapping have been successful in producing high-resolution digital imagers and projectors. This new generation of panoramic lenses includes catadioptric panoramic lenses, panoramic annular lenses, visible/IR fisheye lenses, anamorphic wide-angle attachments, and visible/IR panomorph lenses. Given that a wide-angle lens images a large field of view on a limited number of pixels, a systematic pixel-to-angle mapping will help the efficient use of each pixel in the field of view. In this paper, we present several modern applications of these modern types of hemispheric lenses. Recently, surveillance and security applications have been proposed and published in Security and Defence symposium. However, modern hemispheric lens can be used in many other fields. A panoramic imaging sensor contributes most to the perception of the world. Panoramic lenses are now ready to be deployed in many optical solutions. Covered applications include, but are not limited to medical imaging (endoscope, rigiscope, fiberscope...), remote sensing (pipe inspection, crime scene investigation, archeology...), multimedia (hemispheric projector, panoramic image...). Modern panoramic technologies allow simple and efficient digital image processing and the use of standard image analysis features (motion estimation, segmentation, object tracking, pattern recognition) in the complete 360° hemispheric area.

  4. 7 CFR 51.1435 - U.S. Commercial Pieces.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false U.S. Commercial Pieces. 51.1435 Section 51.1435 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards... STANDARDS) United States Standards for Grades of Shelled Pecans Grades § 51.1435 U.S. Commercial Pieces. The...

  5. 75 FR 28051 - Public Workshop: Pieces of Privacy

    Science.gov (United States)

    2010-05-19

    ... DEPARTMENT OF HOMELAND SECURITY Office of the Secretary Public Workshop: Pieces of Privacy AGENCY: Privacy Office, DHS. ACTION: Notice announcing public workshop. SUMMARY: The Department of Homeland Security Privacy Office will host a public workshop, ``Pieces of Privacy.'' DATES: The workshop will be...

  6. One Piece Orbitozygomatic Approach Based on the Sphenoid Ridge Keyhole

    DEFF Research Database (Denmark)

    Spiriev, Toma; Poulsgaard, Lars; Fugleholm, Kåre

    2016-01-01

    The one-piece orbitozygomatic (OZ) approach is traditionally based on the McCarty keyhole. Here, we present the use of the sphenoid ridge keyhole and its possible advantages as a keyhole for the one-piece OZ approach. Using transillumination technique the osteology of the sphenoid ridge was exami...

  7. Sigtuna Think Piece 9 Climate Change Education Research: What It ...

    African Journals Online (AJOL)

    Sigtuna Think Piece 9 Climate Change Education Research: What It Could Be and Why It Matters. ... Southern African Journal of Environmental Education ... The purpose of this think piece is to situate climate change education research in the context of research traditions, approaches and methods that are common to the ...

  8. Spontaneous bilateral anterior partial in-the-bag intraocular lens dislocation following routine annual eye examination.

    Science.gov (United States)

    Ford, Joshua R; Werner, Liliana; Owen, Leah; Vasavada, Shail A; Crandall, Alan

    2014-09-01

    We present the case of an 81-year-old man with pseudoexfoliation syndrome (PXF) in whom spontaneous bilateral anterior partial in-the-bag intraocular lens (IOL) dislocation was diagnosed following a routine dilated examination that demonstrated only mild pseudophacodonesis with no evidence of subluxation. Uneventful cataract surgery with placement of single-piece hydrophobic acrylic posterior chamber IOLs had been performed in both eyes 7 years previously. Bilateral IOL repositioning with scleral fixation was performed to correct the dislocation. Postoperative examinations showed remarkable improvement in visual acuity and IOL stability. We hypothesize that zonular weakness secondary to PXF predisposed the patient to bilateral IOL partial dislocation. Pupil dilation in the setting of mild pseudophacodonesis at the time of routine examination may have been a precipitating factor. To our knowledge, bilateral IOL subluxation/dislocation has been described in a limited number of case reports. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2014 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  9. Crystalline lens radioprotectors

    International Nuclear Information System (INIS)

    Belkacemi, Y.; Pasquier, D.; Castelain, B.; Lartigau, E.; Warnet, J.M.

    2003-01-01

    During more than a half of century, numerous compounds have been tested in different models against radiation-induced cataract. In this report, we will review the radioprotectors that have been already tested for non-human crystalline lens protection. We will focus on the most important published studies in this topic and the mechanisms of cyto-protection reported in. vitro and in. vivo from animals. The most frequent mechanisms incriminated in the cyto-protective effect are: free radical scavenging, limitation of lipid peroxidation, modulation of cycle progression increase of intracellular reduced glutathione pool, reduction of DNA strand breaks and limitation of apoptotic cell death. Arnifostine (or Ethyol) and anethole dithiolethione (or Sulfarlem), already used clinically as chemo- and radio-protectants, could be further test?r for ocular radioprotection particularly for radiation-induced cataract. (author)

  10. Application of SFM and laser scanning technology to the description of mosaics piece by piece

    Directory of Open Access Journals (Sweden)

    O. Ajioka

    2014-06-01

    Full Text Available Mosaic floors of surviving buildings in Ostia have been mainly recorded in photographs. From 2008, Japanese research group carries out a project of 3d measuring of the whole structure of ancient Roman city Ostia using laser scanners, including its landscape, city blocks, streets, buildings, wall paintings and mosaics. The laser scanner allows for a more detailed analysis and a greater potential for recording mosaics. We can record the data of mosaics, which are described piece by piece. However it is hard to acquire enough high dense point cloud and the internal camera of the laser scanner produce low quality images. We introduce a possible technology of 3D recording of mosaics with high-quality colour information; SFM. The use of this technique permits us to create 3D models from images provided from a CCD camera without heavy and large laser scanners. We applied SFM system to different three types of the mosaics laid down on the floors of "the House of the Dioscuroi", "the Insula of the Muse" and "the House of Jove and Ganymede", and created high resolution orthographic images. Then we examined to compare these orthographic images with that are created from the point cloud data. As a result, we confirmed that SFM system has sufficient practical utility for the mosaic research. And we present how much of density of point cloud or ground resolution are required for the documentation of mosaics accurately.

  11. Application of SFM and laser scanning technology to the description of mosaics piece by piece

    Science.gov (United States)

    Ajioka, O.; Hori, Y.

    2014-06-01

    Mosaic floors of surviving buildings in Ostia have been mainly recorded in photographs. From 2008, Japanese research group carries out a project of 3d measuring of the whole structure of ancient Roman city Ostia using laser scanners, including its landscape, city blocks, streets, buildings, wall paintings and mosaics. The laser scanner allows for a more detailed analysis and a greater potential for recording mosaics. We can record the data of mosaics, which are described piece by piece. However it is hard to acquire enough high dense point cloud and the internal camera of the laser scanner produce low quality images. We introduce a possible technology of 3D recording of mosaics with high-quality colour information; SFM. The use of this technique permits us to create 3D models from images provided from a CCD camera without heavy and large laser scanners. We applied SFM system to different three types of the mosaics laid down on the floors of "the House of the Dioscuroi", "the Insula of the Muse" and "the House of Jove and Ganymede", and created high resolution orthographic images. Then we examined to compare these orthographic images with that are created from the point cloud data. As a result, we confirmed that SFM system has sufficient practical utility for the mosaic research. And we present how much of density of point cloud or ground resolution are required for the documentation of mosaics accurately.

  12. Rehabilitations with immediate loading of one-piece implants stabilized with intraoral welding.

    Science.gov (United States)

    Pasqualini, M E; Lauritano, D; Rossi, F; Dal Carlo, L; Shulman, M; Meynardi, F; Colombo, D; Manenti, P; Comola, G; Zampetti, P

    2018-01-01

    The authors present an implant prosthesis procedure that uses screws on one-piece implants connected with a titanium pin at their abutment level and one supporter titanium bar in order to guarantee immediate stabilization. These can be implanted and fitted with customized temporary crowns in a single surgical procedure, restoring function and aesthetics and consenting recovery of the bone deficit with reduced healing times and limited patient discomfort. One-piece wide-diameter titanium screw implants with thread measurements of 2.1 and 2.6 mm (smaller diameter) up to diameter of 4.5 mm with one abutment of 2.0 and 2.5 mm respectively, were positioned and splinted by intraoral welding. One-piece titanium implants were used together with a pin (needle) titanium implant as supporting structure to achieve deep stabilization. The Scialom-like pin has a diameter of 1.2 mm and it is long enough to reach deep cortical bone that is “bicorticalism”. The One-piece implant is tightly connected to the needle implant by means of Mondani intra-oral welding technique. In severely atrophic anterior maxilla, the use of this method allows the immediate loading of a fixed resin prosthesis soon after surgery. These implants yielded satisfactory functional and aesthetic outcome in bone-deficient upper anterior sectors, without invasive regenerative procedures. The low invasiveness of this approach also consents rapid healing, reduced biological burden and greater patient benefit.

  13. Creep rupture of mild steel compact tension test pieces

    International Nuclear Information System (INIS)

    Priddle, E.K.

    1978-10-01

    Creep rupture lives have been determined for compact tension and unnotched tensile test pieces of mild steel at 450 0 C. Three sizes of compact tension specimens were used in which the ratios of reference stress to elastic stress intensity factor were 2.76, 4.78 and 6.6 (msup(-1/2)). The analysis of results in terms of either initial reference stress or stress intensity was unable to reduce the data to a single failure curve. An empirical correlation was found between rupture time and a reference stress/crack length combination where t = 2.46 x 10 20 sub(σref) sup(-8.96) asup(-1.56) (units hours, MPa and metres). This equation has no valid application to materials or specimens other than those from which it was derived. Reported data for 1/2Cr Mo V and 2 1/4Cr Mo steels at 565 0 C were also correlated by this approach. (author)

  14. Contact Lens Wear at Altitude: Subcontact Lens Bubble Formation

    Science.gov (United States)

    1987-11-01

    incidence of (PMMA) lenses . Reported here are the results of contact lens subcontact lens bubble formation under scleral lenses at bubble studies with soft...vision from formation of large bubbles greater than 6,096 m (20,000 It). With soft contact lenses , bubble under their contact lenses . They also found...always located at the limbus and were without sequela to vision or corneal epithelial integrity. scleral lenses used by Jaeckle were permeable to gases

  15. Straylight Measurements in Contact Lens Wear

    NARCIS (Netherlands)

    van der Meulen, Ivanka J. E.; Engelbrecht, Leonore A.; van Vliet, Johannes M. J.; Lapid-Gortzak, Ruth; Nieuwendaal, Carla P.; Mourits, Maarten P.; Schlingemann, Reinier O.; van den Berg, Thomas J. T. P.

    2010-01-01

    Purpose: (1) To quantify the effect of contact lens wear on straylight in rigid and soft contact lens wearers and (2) to relate findings to morphological changes and subjective complaints. Methods: Straylight was measured using the Oculus C-Quant during contact lens wear and after contact lens

  16. The spectral sensitivity of the lens eyes of a box jellyfish, Tripedalia cystophora (Conant)

    DEFF Research Database (Denmark)

    Coates, Melissa M; Garm, Anders; Theobald, Jamie C

    2006-01-01

    Box jellyfish, or cubomedusae (class Cubozoa), are unique among the Cnidaria in possessing lens eyes similar in morphology to those of vertebrates and cephalopods. Although these eyes were described over 100 years ago, there has been no work done on their electrophysiological responses to light. We...... used an electroretinogram (ERG) technique to measure spectral sensitivity of the lens eyes of the Caribbean species Tripedalia cystophora. The cubomedusae have two kinds of lens eyes, the lower and upper lens eyes. We found that both lens eye types have similar spectral sensitivities, which likely...... result from the presence of a single receptor type containing a single opsin. The peak sensitivity is to blue-green light. Visual pigment template fits indicate a vitamin A-1 based opsin with peak sensitivity near 500 nm for both eye types....

  17. [Suggestions to strengthen quality management of herbal decoction pieces--based on production chain of herbal decoction pieces].

    Science.gov (United States)

    Liu, Yan; Nie, Qing; Chen, Jing

    2015-08-01

    With the development of society and the improvement of people's living standards, the effect of Chinese medicine in treatment and health care is more and more prominent. The herbal decoction pieces are the important part of Chinese medicine,it can be applied directly to clinical treatment and it's also the raw material of Chinese patent medicine. Therefore, the quality of herbal decoction pieces is quite important. The parts of the production of herbal decoction pieces are numerous, and there are possibilities of adverse effects on the quality of the herbal decoction pieces in every part. In this paper, we based on the production chain of herbal decoction pieces, analyzed the main problem that affect the quality of herbal decoction pieces in the part of selection of Chinese herbal medicines, planting, purchasing, processing, packaging, storage and transport, such as the poor quality of seed and seedlings of plant-based Chinese medicines, some plants left their place of origin and have been introduced in the place that is not suitable for this kind of plant, the insufficient growth time and the excessive harmful substances. The purchasers and the accepters lack of professional knowledge and professional ethics. The mechanism of processing is not clear, the standards can not be uniformed, and lack of qualified person in processing, etc. So we suggest: intensify the basic research of key scientific issues. Improve the quality of persons who work in herbal decoction pieces; Establish an "integration" mode of operation in herbal decoction pieces enterprise; Breeding high quality plant resources, establish the large-scale planting basement; Make the packing of herbal decoction pieces standard; Establish the modernization traditional Chinese medicine logistics enterprise.

  18. Contact Lens Related Corneal Ulcer

    OpenAIRE

    Loh, KY; Agarwal, P

    2010-01-01

    A corneal ulcer caused by infection is one of the major causes of blindness worldwide. One of the recent health concerns is the increasing incidence of corneal ulcers associated with contact lens user especially if the users fail to follow specific instruction in using their contact lenses. Risk factors associated with increased risk of contact lens related corneal ulcers are: overnight wear, long duration of continuous wear, lower socio-economic classes, smoking, dry eye and poor hygiene. Th...

  19. A course in lens design

    CERN Document Server

    Velzel, Chris

    2014-01-01

    A Course in Lens Design is an instruction in the design of image-forming optical systems. It teaches how a satisfactory design can be obtained in a straightforward way. Theory is limited to a minimum, and used to support the practical design work. The book introduces geometrical optics, optical instruments and aberrations. It gives a description of the process of lens design and of the strategies used in this process. Half of its content is devoted to the design of sixteen types of lenses, described in detail from beginning to end. This book is different from most other books on lens design because it stresses the importance of the initial phases of the design process: (paraxial) lay-out and (thin-lens) pre-design. The argument for this change of accent is that in these phases much information can be obtained about the properties of the lens to be designed. This information can be used in later phases of the design. This makes A Course in Lens Design a useful self-study book, and a suitable basis for an intro...

  20. A Primer of Easy Pieces: Teaching through Typical Narrative.

    Science.gov (United States)

    Waldman, Peter

    1982-01-01

    A "Form Primer," developed for and used in an introductory architectural design course at Princeton University, is explained and illustrated. The concept holds that architecture is made up of a typology of pieces that are composed into a whole. (MSE)

  1. One-Piece Faraday Generator: A Paradoxical Experiment from 1851

    Science.gov (United States)

    Crooks, M. J.; And Others

    1978-01-01

    Describes an experiment based on Faraday's one-piece generator, where the rotating disk is replaced by a cylindrical permanent magnet. Explains the apparent paradox that an observer in an inertial frame could measure his absolute velocity. (GA)

  2. Gabor lens theory

    International Nuclear Information System (INIS)

    Irani, A.A.

    1978-01-01

    The principle of using the space charge of an electron cloud to focus ion beams was first proposed by Gabor. Electrons are to be confined radially by means of an axial magnetic field B/sub z/ and axially by means of externally applied electric fields E/sub z/. An ion beam of charge density n/sub i/ much less than n/sub e/, the electron charge density can then be focused by the radial electric field set up by the electron cloud. The case considered here is that of a hollow cylindrical conductor charged to a potential +V with grounded rings on either side to set up the axial E/sub z/ field. A solenoid wound around the central conductor supplies the B/sub z/ field. Theoretical calculations are carried out for n/sub e/ maximum as a function of B/sub z/ due to radial confinement and V due to axial confinement and the focal length of the Gabor Lens is calculated

  3. Not only hard contact lens wear but also soft contact lens wear may be associated with blepharoptosis

    NARCIS (Netherlands)

    I. Bleyen (Isabel); C.A. Hiemstra; T. Devogelaere (Thibaut); W.A. van den Bosch (Willem); R.J. Wubbels (René J.); A.D.A. Paridaens (Dion)

    2011-01-01

    textabstractObjective: The authors attempt to establish an association between prolonged hard and soft contact lens wear and ptosis. Design: Single-center retrospective consecutive series. Participants: All patients between 18 and 50 years of age who were diagnosed with unilateral or bilateral

  4. Immunoglobulin Concentration in Tears of Contact Lens Wearers

    OpenAIRE

    Maurya, Rajendra P.; Bhushan, Prashant; Singh, Virendra P.; Singh, Mahendra K.; Kumar, Prakash; Bhatia, Ravindra P.S.; Singh, Usha

    2014-01-01

    Purpose: To evaluate changes in the concentration of tear immunoglobulins in contact lens wearers. Methods: A total of 45 cases including 23 contact lens wearers (43 eyes) and 22 age and sex matched healthy controls having no ocular pathology were studied for immunoglobulins (IgA, IgG, IgM) in their tears by single radial immunodiffusion method. Results: Most of the cases used soft (56.6%) and semi-soft gas permeable (30.4%) contact lenses. Tear IgM was detected in only 17.4% and tear I...

  5. Ball Lens Fiber Optic Sensor based Smart Handheld Microsurgical Instrument.

    Science.gov (United States)

    Song, Cheol; Gehlbach, Peter L; Kang, Jin U

    2013-03-20

    During freehand performance of vitreoretinal microsurgery the surgeon must perform precise and stable maneuvers that achieve surgical objectives and avoid surgical risk. Here, we present an improved smart handheld microsurgical tool which is based on a ball lens fiber optic sensor that utilizes common path swept source optical coherence tomography. Improvements include incorporation of a ball lens single mode fiber optic probe that increases the working angle of the tool to greater than 45 degrees; and increases the magnitude of the distance sensing signal through water. Also presented is a cutting function with an improved ergonomic design.

  6. Optimization of the transition piece applying genetic algorithms

    International Nuclear Information System (INIS)

    Gallegos Munoz, A.; Ayala-Ramirez, V.; Alfaro-Ayala, J.A.; Toledo Acosta, B.M.

    2011-01-01

    The geometric optimization of the gas turbine transition piece, applying the Computational Fluid Dynamics (CFD) and Genetic Algorithms (GA), to obtain a uniform temperature and velocity distribution in the center of the outlet section, is presented. The study is carried out considering different dimensions of the transition piece which were defined by the genetic algorithm analysis. In each case, the temperature and velocity contours of the combustion gases are examined along the transition piece and outlet section, comparing the radial and circumferential velocity and temperature profiles. In this study, it is important to know the temperature and velocity profiles at the outlet of the transition piece, because they have impact on the vanes and blades of the first stage of the gas turbine. The study considers a steady state three-dimensional model, using FLUENT version 6.3.26 and a code of genetic algorithms where the geometric parameters were analyzed. To obtain the results, a structured grid about 5.1 million cells with second-order upwind scheme and coupled solver was applied. The results show the effect of the geometry of the transition piece in the velocity and temperature profiles at the outlet area, where the change of the cross sectional area influences the contours. A smooth change in the cross sectional section allows a uniform temperature and velocity distribution at the outlet section of the transition piece. The peak value of the temperature is decreased about 5.5% (11.4 K) in the radial direction whereas the velocity is decreased 3.62% (4.27 m/s). The peak value of the temperature in the circumferential direction is decreased about 3.33% (45.51 K) whereas velocity is decreased 3.63% (4.171 m/s). The new geometry of the transition piece leads to a diminution of the average turbine inlet temperature (TIT) of about 2.32% (28.29 K) and the average velocity of about 7.73% (4.217 m/s). - Highlights: → We apply two tools of analysis to optimize the

  7. An integral-field spectroscopic strong lens survey

    Energy Technology Data Exchange (ETDEWEB)

    Bolton, Adam S [Harvard-Smithsonian Center for Astrophysics, 60 Garden St. MS-20, Cambridge, MA 02138 (United States); Burles, Scott [Department of Physics and Kavli Institute, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02139 (United States)

    2007-12-15

    We present the observational results of a survey for strong gravitational lens systems consisting of extended emission-line galaxies lensed by intervening early-type galaxies, conducted using integral field units (IFUs) of the Magellan IMACS and Gemini GMOS-N spectrographs. These data are highly valuable for corroborating the lensing interpretation of Hubble Space Telescope imaging data. We show that in many cases, ground-based IFU spectroscopy is in fact competitive with space-based imaging for the measurement of the mass model parameters of the lensing galaxy. We demonstrate a novel technique of three-dimensional gravitational lens modeling for a single lens system with a resolved lensed rotation curve. We also describe the details of our custom IFU data analysis software, which performs optimal multi-fiber extraction, relative and absolute wavelength calibration to a few hundredths of a pixel RMS and nearly Poisson-limited sky subtraction.

  8. An integral-field spectroscopic strong lens survey

    International Nuclear Information System (INIS)

    Bolton, Adam S; Burles, Scott

    2007-01-01

    We present the observational results of a survey for strong gravitational lens systems consisting of extended emission-line galaxies lensed by intervening early-type galaxies, conducted using integral field units (IFUs) of the Magellan IMACS and Gemini GMOS-N spectrographs. These data are highly valuable for corroborating the lensing interpretation of Hubble Space Telescope imaging data. We show that in many cases, ground-based IFU spectroscopy is in fact competitive with space-based imaging for the measurement of the mass model parameters of the lensing galaxy. We demonstrate a novel technique of three-dimensional gravitational lens modeling for a single lens system with a resolved lensed rotation curve. We also describe the details of our custom IFU data analysis software, which performs optimal multi-fiber extraction, relative and absolute wavelength calibration to a few hundredths of a pixel RMS and nearly Poisson-limited sky subtraction

  9. Performance evaluation of macro lens in digital close range photogrammetry

    Science.gov (United States)

    Yanagi, H.; Chikatsu, H.

    2009-08-01

    Recently, the documentation and visualization of various cultural heritages have been receiving attention, and a small Buddha such as less than 10 cm tall which was stored in the womb of Buddha is also included in cultural heritages. Zoom lenses are generally used to document these small objects and thus conserve the cultural heritage. However, there exist certain issues pertaining to the use of zoom lenses for such digital documentation. These issues include image sharpness and distortions that occur with changes in focal length setting, and in particular, the depth of field is issue from application standpoint such as documentation of the small cultural heritage. On the other hand, macro lenses can be used to capture sharp images of small objects from the view point of working distance, and its depth of field is related to the aperture of the camera. In order to evaluate the effectiveness of macro lenses in digital close range photogrammetry, macro lens and zoom lens were mounted on a digital single lens reflex camera (Canon EOS20D, 8.2 Mega pixels). This paper deals in a first part with comparative evaluations for both lenses with respect to their lens distortion, imaging mode, and calibration aspects. The results indicated that macro lenses were more suitable for digital close range photogrammetry. Calibration tests are performed to demonstrate the effectiveness and practicability of macro lens in close range photogrammetic applications.

  10. Predicting scleral GP lens entrapped tear layer oxygen tensions.

    Science.gov (United States)

    Jaynes, Jared M; Edrington, Timothy B; Weissman, Barry A

    2015-02-01

    Over the past decade, utilization of scleral gas permeable (GP) contact lenses has steadily increased. Scleral GP lenses offer yet another option for patients suffering from visually debilitating corneal and tear conditions. Oxygen delivery to the cornea in the presence of a contact lens system continues to be a subject of interest, and scleral GP lenses are no exception. This paper utilizes an existing model based on simultaneous two lens systems (piggyback lenses) as a resistance to oxygen in series, and applies this model to scleral GP lens systems. Theoretical oxygen tensions are calculated for tear layers trapped beneath scleral contact lens systems and the anterior corneal surface with a simple single chamber corneal model using a computer software spreadsheet. Only the best case scenario for current scleral gas permeable lenses (thickness and Dk)/tear layer values allow sufficient tear layer oxygen tension (approximately 100 mmHg) to preclude corneal hypoxia. The results of the spreadsheet model suggest that clinicians would be prudent to prescribe scleral GP lenses manufactured in the highest Dk materials available and to fit without excessive corneal clearance to minimize anterior segment hypoxia. Copyright © 2014 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  11. Cionni ring and in-the-bag intraocular lens implantation for subluxated lenses: a prospective case series.

    Science.gov (United States)

    Vasavada, Abhay R; Praveen, Mamidipudi R; Vasavada, Viraj A; Yeh, Ru-Yin; Srivastava, Samaresh; Koul, Archana; Trivedi, Rupal H

    2012-06-01

    To report the intraoperative performance and postoperative outcomes of the Cionni-modified capsule tension ring (CTR) implantation in eyes with subluxated lenses. Prospective, observational case series. This study was carried out at Iladevi Cataract & IOL Research Centre, Ahmedabad, India. The study population comprised 41 eyes with subluxated lenses that underwent lens extraction, capsular bag fixation with modified CTR, and in-the-bag single-piece AcrySof intraocular lens (IOL) implantation. Main outcome measures were intraoperative performance and postoperative best-corrected visual acuity (BCVA), IOL centration, and complications. The mean age was 29.46 ± 16.16 years (3-68 years). Mean extent of subluxation was 6.1 ± 1.0 clock hours. Preoperatively, vitreous was detected in the anterior chambers of 5 eyes (12.2%). Two-port anterior chamber vitrectomy was performed in 2 eyes. Mean follow-up was 45.8 ± 2.9 months. Mean preoperative BCVA was 0.66 ± 0.22 logMAR (35 eyes). Mean postoperative BCVA at final follow-up was 0.33 ± 0.21 logMAR (41 eyes) (P IOL decentration was noted and repositioning was required in 2 eyes. Posterior capsule opacification developed in 14 eyes (34.2%); 12 eyes (29.3%) required Nd:YAG capsulotomy. Other complications included cystoid macular edema in 1 eye (2.4%), posterior synechiae in 1 eye (2.4%), and retinal detachment in 1 eye (2.4%). In-the-bag implantation of a Cionni-modified CTR with IOL appears to be a safe option in eyes with subluxated cataract, ensuring a stable IOL with few complications. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. [Contact lens care and maintenance].

    Science.gov (United States)

    Bloise, L

    2017-04-01

    All contact lenses with replacement schedules longer than daily must be maintained. At each step of their use, the lenses may be contaminated. Contact lens solutions perform the essential functions of cleaning, decontaminating and preserving the lenses to prevent infectious problems and improve wearing comfort. Contact lens contamination essentially comes from hands, cleaning solutions, cases, water and the environment. The pathogenic microorganisms are mainly Gram-negative bacteria, fungi and amoebae. Contact lens deposits may or may not have an organic origin. Their presence increases the risk of infection because they serve as a nutrient matrix for microbes, and they are responsible for wearing discomfort. Contact lens solutions differ in their composition, their mechanism of action and the concentration of the various agents. To prescribe the best lens care system to each wearer and for each material, it is necessary to be very familiar with them. Maintenance is the main cause of discomfort with contact lenses, either through improper use, solution-material incompatibility, or a reaction of the wearer to the components. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  13. The SNAP Strong Lens Survey

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, P.

    2005-01-03

    Basic considerations of lens detection and identification indicate that a wide field survey of the types planned for weak lensing and Type Ia SNe with SNAP are close to optimal for the optical detection of strong lenses. Such a ''piggy-back'' survey might be expected even pessimistically to provide a catalogue of a few thousand new strong lenses, with the numbers dominated by systems of faint blue galaxies lensed by foreground ellipticals. After sketching out our strategy for detecting and measuring these galaxy lenses using the SNAP images, we discuss some of the scientific applications of such a large sample of gravitational lenses: in particular we comment on the partition of information between lens structure, the source population properties and cosmology. Understanding this partitioning is key to assessing strong lens cosmography's value as a cosmological probe.

  14. Automated Fresnel lens tester system

    Energy Technology Data Exchange (ETDEWEB)

    Phipps, G.S.

    1981-07-01

    An automated data collection system controlled by a desktop computer has been developed for testing Fresnel concentrators (lenses) intended for solar energy applications. The system maps the two-dimensional irradiance pattern (image) formed in a plane parallel to the lens, whereas the lens and detector assembly track the sun. A point detector silicon diode (0.5-mm-dia active area) measures the irradiance at each point of an operator-defined rectilinear grid of data positions. Comparison with a second detector measuring solar insolation levels results in solar concentration ratios over the image plane. Summation of image plane energies allows calculation of lens efficiencies for various solar cell sizes. Various graphical plots of concentration ratio data help to visualize energy distribution patterns.

  15. Compliance among soft contact lens wearers.

    Science.gov (United States)

    Kuzman, Tomislav; Kutija, Marija Barisić; Masnec, Sanja; Jandroković, Sonja; Mrazovac, Danijela; Jurisić, Darija; Skegro, Ivan; Kalauz, Miro; Kordić, Rajko

    2014-12-01

    Contact lens compliance is proven to be crucial for preventing lens wear-related complications because of the interdependence of the steps in lens care regime and their influence on lens system microbial contamination. Awareness of the patients' lens handling compliance as well as correct recognition of non-compliant behaviours is the basis for creating more targeted strategies for patient education. The aim of this study was to investigate compliance among soft contact lens (SCL) wearers in different aspects of lens care handling and wearing habits. In our research 50 asymptomatic lens wearers filled out a questionnaire containing demographic data, lens type, hygiene and wearing habits, lenses and lens care system replacement schedule and self-evaluation of contact lens handling hygiene. We established criteria of compliance according to available manufacturer's recommendations, prior literature and our clinical experience. Only 2 (4%) of patients were fully compliant SCL wearers. The most common non-compliant behaviours were insufficient lens solution soaking time (62%), followed by failure to daily exchange lens case solution and showering while wearing lenses. 44% of patients reported storing lenses in saline solution. Mean lens storage case replacement was 3.6 months, with up to 78% patients replacing lens case at least once in 3 months. Average grade in self evaluating level of compliance was very good (4 +/- 0.78) (from 1-poor level of hygiene to 5-great level of hygiene). Lens wearers who reported excessive daily lens wear and more than 10 years of lens wearing experience were also found to be less compliant with other lens system care procedures. (t = -2.99, df=47, p lens system maintenance steps. Most common non-compliant behaviours were the ones that are crucial for maintaining lens sterility and preventing infection. Despite the low objective compliance rate, self grading was relatively high. Therefore, these results indicate the need for patient

  16. Influence of use of ultrasound on the mechanical properties of plated pieces by welding in ultrasonic field

    Directory of Open Access Journals (Sweden)

    Gh. Amza

    2015-07-01

    Full Text Available Plating by welding in an ultrasonic field represents a technological solution to increase resistance to corrosion and / or wear of pieces of the machinery industry. Research has been carried out for two types of parts, namely a piece of flange end type and bonnet type made of AISI 4130 steel, and as filler material for plating was used Inconel 625 Fe developed as electrode wire with a diameter of ø 1.2 / mm. The plating was done by depositing a single layer by welding in ultrasonic field, welding process in Ar 100/ % environment non-consumable tungsten electrode, WIG process, and when using ultrasonic activation it was used a longitudinal and a transverse wave with a frequency of 15 / kHz. For pieces plated by welding there have been made attempts of the hardness and tensile and bend shock.

  17. Computer-aided lens assembly

    Science.gov (United States)

    Tomlinson, Richard; Alcock, Rob; Petzing, Jon; Coupland, Jeremy

    2004-01-01

    We propose a computer-aided method of lens manufacture that allows assembly, adjustment, and test phases to be run concurrently until an acceptable level of optical performance is reached. Misalignment of elements within a compound lens is determined by a comparison of the results of physical ray tracing by use of an array of Gaussian laser beams with numerically obtained geometric ray traces. An estimate of misalignment errors is made, and individual elements are adjusted in an iterative manner until performance criteria are achieved. The method is illustrated for the alignment of an air-spaced doublet.

  18. Acanthamoeba keratitis. Contact lens and noncontact lens characteristics.

    Science.gov (United States)

    Chynn, E W; Lopez, M A; Pavan-Langston, D; Talamo, J H

    1995-09-01

    To identify potential differences in time to diagnosis and final visual outcome between contact lens and noncontact lens users with Acanthamoeba keratitis. Prior studies have shown early diagnosis and therapy to be related to outcome but have not analyzed differences among patients with and without contact lenses. A retrospective analysis of 11 consecutive cases (involving 13 eyes) of Acanthamoeba keratitis diagnosed at one institution over a 3-year period. Mean time to diagnosis was significantly longer in noncontact lens users versus those who wore contact lenses (mean, 5.8 versus 3.3 weeks). Fifty percent of patients who did not wear contact lenses had a poor outcome (visual acuity worse than 20/40 or penetrating keratoplasty) versus 14% of patients who wore contact lenses. Diagnoses were made later in patients without contact lenses, and these patients had a worse visual outcome than those with Acanthamoeba keratitis who wore contact lenses. All patients with unresponsive microbial keratitis, even those without contact lens use, should be evaluated for Acanthamoeba.

  19. Feminist Erotica and Agency @ The Love Piece Club

    OpenAIRE

    DALES, Laura

    2008-01-01

    The Love Piece Club is a shop devoted to sex goods for women, located in Tokyo and online at www.lovepiececlub.com. As well as online shopping, the website offers regular columns, articles and photo-essays on subjects related to sexuality and women's lives. The site and shop are managed by Kitahara Minori, a writer, businesswoman and advocate for feminist erotica. This paper explores the Love Piece Club as a discursive site – its potential meanings and its significance as a feminist work in p...

  20. Scanning electron microscopic characteristics of commercially available 1- and 3-piece intraocular lenses.

    Science.gov (United States)

    Brockmann, Tobias; Brockmann, Claudia; Nietzsche, Sandor; Bertelmann, Eckart; Strobel, Juergen; Dawczynski, Jens

    2013-12-01

    To evaluate commercially available 1- and 3-piece intraocular lenses (IOLs) with scanning electron microscopy (SEM). Department of Ophthalmology and Electron Microscopy Center, University Hospital Jena, Jena, Germany. Experimental study. Seven +23.0 diopter IOLs of different design and material and from different manufacturers were chosen for a detailed assessment. Scanning electron microscopy was used at standardized magnifications to assess typical IOL characteristics. The particular focus was the optic edge, the optic surface, the haptic–optic junction, and the haptic. All square-edged IOLs had a curvature radius of less than 10 μm, while the mean optic edge thickness ranged between 216 μm and 382 μm. A 360-degree square-edged boundary was present in all 3-piece IOLs and in a single 1-piece model. Relevant production remnants on the optic edge were observed in 1 case. Regarding the haptic, 3-piece IOLs had uniformly shaped fibers with a mean thickness of 177 μm ± 51 (SD) (range 116 to 220 μm). Chemical adhesives were used to attach the haptic in 1 case, where alterations of the IOL material were observed. In another case, the haptic fiber was press-fitted into the optic, which resulted in bulging of the optic profile. Inspection of surface characteristics showed wavelike patterns in 2 IOLs. Taking clinical relevance into account, all IOLs were of high manufacturing quality. Certain attention was paid in creating a sharp optic edge. Surface irregularities of 2 IOLs were attributed to the manufacturing technique. Methods for implementing the haptic–optic junction were diverse.

  1. A microcapillary lens for X-rays

    CERN Document Server

    Dudchik, Y I

    1999-01-01

    A new design of a compound refractive lens for X-rays is proposed. The lens is made as a set of glue microlenses placed in a glass capillary. The technique of lens fabrication is described. Results of ray tracing calculations for 8 and 15 keV photons are represented.

  2. Qualification of a Null Lens Using Image-Based Phase Retrieval

    Science.gov (United States)

    Bolcar, Matthew R.; Aronstein, David L.; Hill, Peter C.; Smith, J. Scott; Zielinski, Thomas P.

    2012-01-01

    In measuring the figure error of an aspheric optic using a null lens, the wavefront contribution from the null lens must be independently and accurately characterized in order to isolate the optical performance of the aspheric optic alone. Various techniques can be used to characterize such a null lens, including interferometry, profilometry and image-based methods. Only image-based methods, such as phase retrieval, can measure the null-lens wavefront in situ - in single-pass, and at the same conjugates and in the same alignment state in which the null lens will ultimately be used - with no additional optical components. Due to the intended purpose of a Dull lens (e.g., to null a large aspheric wavefront with a near-equal-but-opposite spherical wavefront), characterizing a null-lens wavefront presents several challenges to image-based phase retrieval: Large wavefront slopes and high-dynamic-range data decrease the capture range of phase-retrieval algorithms, increase the requirements on the fidelity of the forward model of the optical system, and make it difficult to extract diagnostic information (e.g., the system F/#) from the image data. In this paper, we present a study of these effects on phase-retrieval algorithms in the context of a null lens used in component development for the Climate Absolute Radiance and Refractivity Observatory (CLARREO) mission. Approaches for mitigation are also discussed.

  3. Immunoglobulin concentration in tears of contact lens wearers.

    Science.gov (United States)

    Maurya, Rajendra P; Bhushan, Prashant; Singh, Virendra P; Singh, Mahendra K; Kumar, Prakash; Bhatia, Ravindra P S; Singh, Usha

    2014-01-01

    To evaluate changes in the concentration of tear immunoglobulins in contact lens wearers. A total of 45 cases including 23 contact lens wearers (43 eyes) and 22 age and sex matched healthy controls having no ocular pathology were studied for immunoglobulins (IgA, IgG, IgM) in their tears by single radial immunodiffusion method. Most of the cases used soft (56.6%) and semi-soft gas permeable (30.4%) contact lenses. Tear IgM was detected in only 17.4% and tear IgG in 43.6% of contact lens wearers, while in controls IgG was detected in 9.1% but none of the controls had IgM. There was a significant rise in total tear IgA (13.17 ± 4.44 mg/dl) in contact lens wearer as compared to controls (8.93 ± 3.79 mg/dl). Rise of tear IgA was more in symptomatic patients (15.38 ± 5.28 mg/dl) and in those wearing hard (19.73 ± 5.43 mg/dl) and semi-soft contact lenses (13.31 ± 5.43 mg/dl). A significant increase in tear IgA was noticed in subjects wearing lenses for >3 years (15.69 ± 5.39 mg/dl). About 43.4% of lens wearers were symptomatic and 80% of their lenses showed deposits and/or haziness. All cases with IgM in tear were symptomatic. The relation of immunoglobulin concentration with increasing duration of wear and material of contact lens shows that tear immunoglobulin rise accrues due to mechanical stimulation, hence contact lenses should not be used for a long period and lenses of hard nature should be discouraged. The maintenance, cleaning and deproteinization of the lenses are of high importance to avoid immunostimulation.

  4. Intermediate results of sutureless intrascleral posterior chamber intraocular lens fixation.

    Science.gov (United States)

    Scharioth, Gabor B; Prasad, Som; Georgalas, Ilias; Tataru, Calin; Pavlidis, Mitrofanis

    2010-02-01

    To report the intermediate multicenter results of a technique of sutureless intrascleral fixation of a standard 3-piece posterior chamber intraocular lens (PC IOL) in the ciliary sulcus. Four European ophthalmology centers. A technique for sutureless intrascleral fixation of the haptics of a standard 3-piece PC IOL was retrospectively evaluated. The technique uses standardized maneuvers to fixate the PC IOL without need for special haptic architecture or preparation or haptic suturing. All patients having IOL implantation by the technique were evaluated for preoperative status (visual acuity, refractive error, preexisting ocular conditions, optical biometry), postoperative status, complications, and need for further surgery. The study evaluated 63 consecutive patients from 4 institutions (4 surgeons). The median follow-up was 7 months. Two dislocated PC IOLs (3.6%) were decentered; the other 61 IOLs (96.8%) were stable and well centered. There were no cases of recurrent dislocation, endophthalmitis, retinal detachment, or glaucoma. Fixation of PC IOL haptics in a limbus-parallel scleral tunnel provided exact centration and axial stability of the IOL and prevented distortion and subluxation in most cases. Copyright 2010 ASCRS and ESCRS. All rights reserved.

  5. The Ultrawideband Leaky Lens Antenna

    NARCIS (Netherlands)

    Bruni, S.; Neto, A.; Marliani, F.

    2007-01-01

    A novel directive and nondispersive antenna is presented: the ultrawideband (UWB) leaky lens. It is based on the broad band Cherenkov radiation occurring at a slot printed between different infinite homogeneous dielectrics. The first part of the paper presents the antenna concept and the UWB design.

  6. ECTOPIC LENS EXTRACTION IN CHILDREN

    Directory of Open Access Journals (Sweden)

    Vladimir Pfeifer

    2002-12-01

    Full Text Available Background. Ectopia lentis continues to be a therapeutic challenge for ophthalmologists. It can occur as an isolated condition, after ocular trauma, in association with other ocular disorders, as part of a systemic mesodermal disease or a complication of general metabolic disorders. Minimal subluxation of the lens may cause no visual symptoms, but in more advanced cases serious optical disturbances arise. The most important is amblyopia. Surgical treatment options include iris manipulation, lens discission, aspiration, intracapsular or extracapsular extraction, and pars plana lensectomy. The choice of surgical technique remains controversial, in part because of the historically poor visual results and high rate of perioperative complications, including vitreous loss and retinal detachment.Methods. We describe a surgical technique based on the use of the Cionni endocapsular tension ring, dry irrigation aspiration of lens material, centration of the capsular bag and foldable intraocular lens implantation into the bag. With mentioned surgical technique 8 patients were operated; 4 boys and 4 girls, together 11 eyes.Results. The final BCVA after follow up period improved in 9 eyes and it remained the same as before operation in one eye. Statistical comparison of preoperative and postoperative visual acuities showed significant improvement. On the other hand there was no correlation between preoperative and postoperative visual acuity.Conclusions. This surgical procedure is an alternative approach in solving this challenging cases of ectopia lentis with good postoperative visual rehabilitation.

  7. Spinning pipe gas lens revisited

    CSIR Research Space (South Africa)

    Mafusire, C

    2008-01-01

    Full Text Available , there is little information on optical phase aberrations and no study to date on the propagation parameters of the laser beam, but has rather remained rooted in the domain of ray optics. Researchers revisit the spinning pipe gas lens in this paper with new...

  8. Bioptics in sutureless intrascleral multifocal posterior chamber intraocular lens fixation.

    Science.gov (United States)

    Pavlidis, Mitrofanis; de Ortueta, Diego; Scharioth, Gabor B

    2011-05-01

    To present a technique for sutureless fixation of a three-piece, multifocal, posterior chamber intraocular lens (IOL) in the ciliary sulcus. A 24-year-old woman presented with bilateral subluxation of the crystalline lens. Two straight sclerotomies were prepared with a 24-gauge cannula 2.0 mm from the limbus 180° apart from each other. The cannula was used to create a 2.0- to 3.0-mm tunnel parallel to the limbus starting from the sclerotomies. The leading haptic of the multifocal IOL was grasped at its tip with end-gripping, 25-gauge forceps and pulled through the sclerotomy. The forceps was used to introduce the IOL haptic into the scleral tunnel parallel to the limbus. Multifocal posterior chamber IOLs were stable and well centered. No postoperative complications occurred in the 16-month follow-up period. Preoperative astigmatism was corrected after IOL implantation with corneal wavefront-guided laser epithelial keratomileusis. Sutureless fixation of multifocal posterior chamber IOL haptics in a scleral tunnel parallel to the limbus can be successful, resulting in long-term centration and three-dimensional axial stability for optimal refractive results. If necessary, postoperative wavefront-guided refractive correction can be performed to optimize final refraction. Copyright 2011, SLACK Incorporated.

  9. Tube entrance lens focus control

    Science.gov (United States)

    Weisser, D. C.; Fifield, L. K.; Kitchen, T. F. G.; Tunningley, T. B.; Lobanov, N. R.; Muirhead, A. G.

    2013-02-01

    The entrance of the accelerator tube in a large electrostatic accelerator imposes a strong lens that dominates the beam optics. The magnification of the lens is large because of the low injection energy, the high voltage gradient of the acceleration tube and the long distance to the terminal. In the absence of the acceleration, the magnification would produce an unacceptably large beam spot at the terminal. The tyranny of the lens is especially irksome when the accelerator is required to operate at a lower terminal voltage than the one corresponding to the nominal gradient at high voltage. One way around the difficulty, used in NEC Pelletron accelerators, is to insert a series of nylon and steel rods that short together units of the acceleration structure at the terminal leaving the ones near the entrance close to the nominal gradient for optimum transmission. This operation takes time and risks the loss of insulating gas. Another alternative used in the 25URC at Oak Ridge National Laboratory, is to focus the beam at the tube entrance, substantially diluting the effect of the entrance lens. The beam then diverges and so requires an additional lens part way to the terminal. This solution is only partially effective and still necessitates use of shorting rods for low voltage operation. The fact that these elaborate strategies are used is evidence that the alternative of lowering the injection energy as the terminal voltage is lowered imposes enough problems that it is not used in practice. We have modeled a solution that controls the voltage gradient at the tube entrance using an external power supply. This not only maintains the focusing effect of the lens but provides the opportunity to tune the beam by adjusting the entrance lens. A 150 kV power supply outside the pressure vessel feeds a controllable voltage through a high voltage feed-through to the fifth electrode of the accelerator tube. Thus 150 kV on this electrode creates the nominal gradient of 30 kV per

  10. Lens stem cells may reside outside the lens capsule: an hypothesis

    Directory of Open Access Journals (Sweden)

    Meyer Rita A

    2007-06-01

    Full Text Available Abstract In this paper, we consider the ocular lens in the context of contemporary developments in biological ideas. We attempt to reconcile lens biology with stem cell concepts and a dearth of lens tumors. Historically, the lens has been viewed as a closed system, in which cells at the periphery of the lens epithelium differentiate into fiber cells. Theoretical considerations led us to question whether the intracapsular lens is indeed self-contained. Since stem cells generate tumors and the lens does not naturally develop tumors, we reasoned that lens stem cells may not be present within the capsule. We hypothesize that lens stem cells reside outside the lens capsule, in the nearby ciliary body. Our ideas challenge the existing lens biology paradigm. We begin our discussion with lens background information, in order to describe our lens stem cell hypothesis in the context of published data. Then we present the ciliary body as a possible source for lens stem cells, and conclude by comparing the ocular lens with the corneal epithelium.

  11. Development of debris-resistant bottom end piece

    International Nuclear Information System (INIS)

    Sohn, Dong Seong; Lee, Jae Kyung; Hwang, Dae Hyun; Yim, Jung Sik; Song, Kee Nam; Oh, Dong Seok; Im, Hyun Tae

    1993-01-01

    Debris-related fuel failures has been identified to be one of the major causes of fuel failures recently occured in nuclear power plants. In order to reduce the possibility of debris-related fuel failures, it is necessary to prevent the debris from reaching to fuel rods. In this regard, it is important to develop Debris-Resistant Bottom End Piece. (Author)

  12. Sigtuna Think Piece 5 Climate Change within Education for ...

    African Journals Online (AJOL)

    This think piece describes a way of including climate change within education for sustainable development (ESD), with a specific ambition to illuminate the moral dimension in a locally relevant way in the teaching. A method – ethical tendency discourse analysis – for creating a locally relevant teaching content that ...

  13. Let's Measure the Dielectric Constant of a Piece of Paper!

    Science.gov (United States)

    Karlow, Edwin A.

    1991-01-01

    Described is a simple circuit with which students can observe the effect of common dielectric materials in a capacitor and measure the dielectric constant of a piece of paper. Discussed are the theory, apparatus construction, and experimental procedures for this activity. (CW)

  14. A piece of paper falling faster than free fall

    International Nuclear Information System (INIS)

    Vera, F; Rivera, R

    2011-01-01

    We report a simple experiment that clearly demonstrates a common error in the explanation of the classic experiment where a small piece of paper is put over a book and the system is let fall. This classic demonstration is used in introductory physics courses to show that after eliminating the friction force with the air, the piece of paper falls with acceleration g. To test if the paper falls behind the book in a nearly free fall motion or if it is dragged by the book, we designed a version of this experiment that includes a ball and a piece of paper over a book that is forced to fall using elastic cords. We recorded a video of our experiment using a high-speed video camera at 300 frames per second that shows that the book and the paper fall faster than the ball, which falls well behind the book with an acceleration approximately equal to g. Our experiment shows that the piece of paper is dragged behind the book and therefore the paper and book demonstration should not be used to show that all objects fall with acceleration g independently of their mass.

  15. Two-piece implants with turned versus microtextured collars.

    NARCIS (Netherlands)

    Cosyn, J.; Sabzevar, M.M.; Wilde, P.C.M. de; Rouck, T. de

    2007-01-01

    Implant companies have been promoting two-piece implants with microtextured collars in the interest of hard tissue preservation and/or soft tissue integration. However, this rationale may not be justified. Based on comparative studies currently available, it is unclear whether microroughened implant

  16. Three-piece Inflatable Penile Prosthesis: Surgical Techniques and ...

    African Journals Online (AJOL)

    Penile prosthesis surgery plays a vital role in the treatment of erectile dysfunction (ED). As far as outcome is concerned, it is one of the most rewarding procedures for both patients and surgeons. We describe our surgical technique for implantation of the three-piece inflatable penile prosthesis and point out the major surgical ...

  17. Think Piece: Re-thinking Education for Sustainable Development as ...

    African Journals Online (AJOL)

    Think Piece: Re-thinking Education for Sustainable Development as Transgressive Processes of Educational Engagement with Human Conduct, Emerging ... theorising the expansive and reflexive learning of citizens and how these processes might produce the desired change towards sustainable development (SD) in ...

  18. One-piece transparent shell improves design of helmet assembly

    Science.gov (United States)

    Jones, R. L.; Okane, J. H.

    1966-01-01

    One-piece transparent helmet shell made of polycarbonate is equipped with a helmet protection pad, a visor assembly, a communications skull cap, and an emergency oxygen supply. This design offers improvements over previous designs in weight, visual field, comfort and protection.

  19. Sigtuna Think Piece 7 Readings for Climate Change: Ecocriticism ...

    African Journals Online (AJOL)

    This think piece elaborates possible research connections between ecocriticism and climate change educational research, addressing the overarching question of what cultural responses to climate change can offer climate change education and climate change education research. It investigates literary critic Louise ...

  20. Sigtuna Think Piece 1 Climate Change Education in Africa ...

    African Journals Online (AJOL)

    Sigtuna Think Piece 1 Climate Change Education in Africa. ... Southern African Journal of Environmental Education ... Though Africa produces less than 10% of total greenhouse gas emissions, the continent was noted as one of the most vulnerable to climate change by the Intergovernmental Panel on Climate Change's ...

  1. Sigtuna Think Piece 10 Reflections on the Sigtuna Climate Change ...

    African Journals Online (AJOL)

    Sigtuna Think Piece 10 Reflections on the Sigtuna Climate Change Education Research Symposium. ... Southern African Journal of Environmental Education ... a short reflection from two Master's level students who participated in the symposium on Climate Change Education held at Sigtunastiftelsen on 28 March 2009.

  2. Subluxation of the crystalline lens: a no-ring approach.

    Science.gov (United States)

    Rodrigues, Antonio Carlos L; Trivedi, Rupal H; Wilson, M Edward

    2012-01-01

    To report the surgical technique and outcomes of a no-ring approach to posterior chamber intraocular lens (IOL) implantation in children and young adults with subluxation of the crystalline lens. A three-piece 5.5-mm hydrophobic acrylic IOL was implanted in which the optic and one haptic were inside the capsular bag and the other haptic was in the ciliary sulcus. The implantations were done in 13 eyes of 10 patients with lens subluxation. One haptic was fixated in the ciliary sulcus by passing it through an operculum-shaped opening in the capsular bag edge, made between 2 and 3 clock hours, clockwise from the middle point of the subluxated area. The mean age of the 10 patients was 12.61 ± 8.04 years and the mean follow-up was 21.38 ± 11.29 months. The mean preoperative and postoperative best-corrected visual acuity (BCVA) was 1.15 ± 0.58 and 0.37 ± 0.17 logarithm of the minimum angle of resolution, respectively, in 11 measured eyes. The postoperative BCVA was 20/40 or better in 4 eyes (36.36%), between 20/40 and 20/60 in 6 eyes (54.54%), and between 20/80 and 20/100 in 1 eye (9.09%). The BCVA improved in all eyes. Postoperative IOL decentration between 1.0 and 1.5 mm occurred in 3 of 13 eyes (23.08%). The results indicate that the no-ring technique allows centration of an IOL implanted into a subluxated capsular bag without using capsule tension rings. Copyright 2012, SLACK Incorporated.

  3. Modern lens antennas for communications engineering

    CERN Document Server

    Thornton, John

    2012-01-01

    The aim of this book is to present the modern design principles and analysis of lens antennas. It gives graduates and RF/Microwave professionals the design insights in order to make full use of lens antennas.  Why do we want to write a book in lens antennas? Because this topic has not been thoroughly publicized, its importance is underestimated. As antennas play a key role in communication systems, recent development in wireless communications would indeed benefit from the characteristics of lens antennas: low profile, and low cost etc.  The major advantages of lens antennas are na

  4. Společné, či oddělené vzdělávání dívek a chlapců? / Co-education or single-sex education?

    Directory of Open Access Journals (Sweden)

    Irena Smetáčková

    2013-10-01

    Full Text Available The article compares co-education and single-sex education. Based oninternational research, the positive and negative sides of both models are discussed. Focusing on gender equality, unreflected coeducation is found problematic because gender stereotypes are usually reproduced. The potential promotion of single-sexeducation in Czech Republic (following international experimental schools should take into account students’ opinions. The article brings the results of a survey (N = 556 that was focused on students’ approaches and experience with single-sex and co-education. Children prefer coeducational settings despite of reporting thegender biased peer harassment and the unequal treatment by teachers.

  5. Contact lens surface by electron beam

    International Nuclear Information System (INIS)

    Shin, Jung Hyuck; Lee, Suk Ju; Hwang, Kwang Ha; Jeon Jin

    2011-01-01

    Contact lens materials needs good biocompatibility, high refractive index, high optical transparency, high water content etc. Surface treat method by using plasma and radiation can modify the physical and/or chemical properties of the contact lens surface. Radiation technology such as electron beam irradiation can apply to polymerization reaction and enhance the functionality of the polymer.The purpose of this study is to modify of contact lens surface by using Eb irradiation technology. Electron beam was irradiated to the contact lens surface which was synthesized thermal polymerization method and commercial contact lens to modify physical and chemical properties. Ft-IR, XP, UV-vis spectrophotometer, water content, oxygen trans-metastability were used to characterize the surface state, physicochemical, and optical property of the contact lens treated with Eb. The water content and oxygen transmissibility of the contact lens treated with Eb were increased due to increase in the hydrophilic group such as O-C=O and OH group on the contact lens surface which could be produced by possible reaction between carbon and oxygen during the Eb irradiation. All of the lenses showed the high optical transmittance above 90%. In this case of B/Es, TES, Ti contact lens, the optical transmittance decreased about 5% with increasing Eb dose in the wavelength of UV-B region. The contact lens modified by Eb irradiation could improve the physical properties of the contact lens such as water content and oxygen transmissibility

  6. Lens decenter and tilt measurement by interferogram

    Science.gov (United States)

    Hung, Min-Wei; Wu, Wen-Hong; Huang, Kuo-Cheng

    2009-11-01

    For the recent years, the vigorous development of the electro-optic industry, particularly the digital camera and the cellular phone camera, has placed a larger and larger demand for the optical devices. Among the optical lens, the aspherical optical lens plays the key component because the aspherical lens may provide better imaging quality then the spherical lens does. For the manufacturing reason, the aspherical lens is prone to a decenter or tilt issue with respect to the optical axes of its two surfaces. To measure decenter and tile error specifically would help to obviate the deficient lens, but most of the present measuring method can't provide this function. This paper proposed a new method to specifically measure the decenter and tile of lens by observing the interferogram of each surface. And the corresponding measuring instrument, which contains interferometer and motion stages, was introduced as well.

  7. Effect of a capsular tension ring on axial intraocular lens position.

    Science.gov (United States)

    Weber, Maria; Hirnschall, Nino; Rigal, Karl; Findl, Oliver

    2015-01-01

    To assess the effect of a capsular tension ring (CTR) on the postoperative anterior chamber depth (ACD). Vienna Institute for Research in Ocular Surgery, Department of Ophthalmology, Hanusch Hospital, Vienna, Austria. Prospective observer- and patient-masked randomized trial. Bilateral small-incision cataract surgery with implantation of a hydrophobic acrylic single-piece intraocular lens (IOL) (Tecnis ZCB00) was performed using a standard technique. Each patient received a CTR in 1 eye (CTR group) and no CTR in the fellow eye (control group). The ACD was measured preoperatively with biometry (IOLMaster 500) and at 1 hour and 12 weeks postoperatively using partial coherence interferometry (ACMaster). The subjective refraction was assessed at 12 weeks. Sixty eyes (30 patients) were included. Preoperatively, the mean axial length was 23.36 mm ± 1.55 (SD) (range 21.01 to 29.46 mm) in the CTR group and 23.37 ± 1.70 mm (range 21.14 to 28.84 mm) in the control group and the mean ACD was 3.06 ± 0.45 mm (range 2.25 to 4.16 mm) and 3.03 ± 0.47 mm (range 2.18 to 4.10 mm), respectively. The differences were not statistically significant (P=.148 and P=.074, respectively). The mean postoperative ACD was 4.83 ± 0.46 mm (range 3.84 to 5.76 mm) in the CTR group and 4.81 ± 0.43 mm (range 3.67 to 5.65 mm) in the control group. The difference between the groups was not statistically significant (P=.329). Implantation of a CTR had no significant influence on the postoperative axial IOL position. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  8. Fish-eye lens designs and their relative performance

    Science.gov (United States)

    Kumler, James J.; Bauer, Martin L.

    2000-10-01

    New panoramic and immersive digital imaging developments have generated increased interest in high performance fisheye camera lenses suitable for 35 mm single lens reflex (SLR) cameras. Special concerns for such applications are the uniformity of illumination and radial image mapping. Because two hemispherical images are digitally stitched together to form a complete 360-degree x 180-degree image, the performance of the lens at the 90 degree (preferably more than 90 degree) edge of the fisheye image is just as important as the center of the image. Lateral color, high order distortion (edge compression) and severe drop-off of illumination at the full field become obvious image defects and cause seams in the immersive image. Fisheye lens designs have widely varying relative illumination and distortion across the hemispherical field of view of the lens. After describing the contributing factors to relative illumination, we survey a collection of fisheye designs and compare their illumination performance, radial mapping and lateral color. A new method of measuring relative illumination and radial mapping in the laboratory is described and results on commercially available fish-eye lenses are presented.

  9. Pathologic evidence of pseudoexfoliation in cases of in-the-bag intraocular lens subluxation or dislocation.

    Science.gov (United States)

    Liu, Erica; Cole, Scott; Werner, Liliana; Hengerer, Fritz; Mamalis, Nick; Kohnen, Thomas

    2015-05-01

    To provide complete histopathologic evaluation of explanted capsular bags that spontaneously dislocated in the late postoperative period, with the main objective being to assess the presence of pseudoexfoliation (PXF) material. Goethe-University Frankfurt, Frankfurt, Germany, and John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. Retrospective case series. Standard gross and light microscopy and complete histopathology were performed on explanted subluxated and dislocated capsular bags containing an intraocular lens (IOL) or a capsular tension ring (CTR) and an IOL. Questionnaires were sent to explanting surgeons, and a patient chart review was performed, when available. The specimens were represented by capsular bags containing an IOL (n = 37) or an IOL-CTR (n = 3). The IOLs included 3-piece hydrophobic acrylic (n = 13), 1-piece hydrophobic acrylic (n = 7), 3-piece silicone (n = 6), 1-piece hydrophilic acrylic (n = 6), 3-piece hydrophilic acrylic (n = 2), and 1-piece poly(methyl methacrylate) (PMMA) (n = 6) designs; all CTRs were PMMA. Soemmering ring formation was mild in 8 specimens, moderate in 18 specimens, and severe in 14 specimens. Excessive contraction of the capsular bag with capsulorhexis phimosis was observed in 24 specimens. Twenty-six specimens had histopathologic evidence of PXF; 13 had a clinical history or evidence of PXF. Pseudoexfoliation might be implicated in a larger proportion of late in-the-bag IOL subluxations and dislocations than previously thought as a result of significant clinical underdiagnosis. This might indicate a need for new considerations during the preoperative and postoperative cataract surgery assessments and follow-up. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  10. Looking beyond the perfect lens

    International Nuclear Information System (INIS)

    Wee, W H; Pendry, J B

    2010-01-01

    The holy grail of imaging is the ability to see through anything. From the conservation of energy, we can easily see that to see through a lossy material would require lenses with gain. The aim of this paper therefore is to propose a simple scheme by which we can construct a general perfect lens, with gain-one that can restore both the phases and amplitudes of near and far fields.

  11. CONTACT LENS RELATED CORNEAL ULCER

    Directory of Open Access Journals (Sweden)

    AGARWAL P

    2010-01-01

    Full Text Available A corneal ulcer caused by infection is one of the major causes of blindness worldwide. One of the recent health concerns is the increasing incidence of corneal ulcers associated with contact lens user especially if the users fail to follow specific instruction in using their contact lenses. Risk factors associated with increased risk of contact lens related corneal ulcers are:overnight wear, long duration of continuous wear, lower socio-economic classes, smoking, dry eye and poor hygiene. The presenting symptoms of contact lens related corneal ulcers include eye discomfort, foreign body sensation and lacrimation. More serious symptoms are redness (especially circum-corneal injection, severe pain, photophobia, eye discharge and blurring of vision. The diagnosis is established by a thorough slit lamp microscopic examination with fluorescein staining and corneal scraping for Gram stain and culture of the infective organism. Delay in diagnosing and treatment can cause permanent blindness, therefore an early referral to ophthalmologist and commencing of antimicrobial therapy can prevent visual loss.

  12. Inspection of complex geometry pieces with an intelligent contact transducer

    International Nuclear Information System (INIS)

    Chatillon, S.; Roy, O.; Mahaut, St.

    2000-01-01

    A new multi-element contact transducer has been developed to improve the inspection of components with complex geometry. The emitting surface is flexible in order to optimize the contact with pieces. An algorithm, based on a simplified geometric model, has been used to determine the delays law which allows to control the focal characteristics of the transmitted field. Acquisition data lead in transmission with an articulated transducer validate the behavior provided by simulation. Thus the optimization of the delays law ensures the transmission of a beam which is homogeneous and controlled during the moving of the transducer. Inspections in echo-pulse mode are implemented on a sample simulating a component controlled on site. Results show that the dynamical adaptation of the delays law to the geometry of the piece leads to very good performances

  13. Device to detect faults on the surfaces of work pieces

    International Nuclear Information System (INIS)

    Savidge, D.H.; Wadsworth, E.

    1979-01-01

    The surface of a work piece, e.g. a steel block, can be scanned by a high-frequency induced eddy current probe. The probe forms the inductive part of a tuned high-frequency oscillator circuit. A buffer amplifier separates the frequency and the amplitude of the output signals received by the oscillator circuit and feeds these to a double-channel receiver. The scanning head can also have several probe coils. (RW) [de

  14. PieceStack: Toward Better Understanding of Stacked Graphs.

    Science.gov (United States)

    Wu, Tongshuang; Wu, Yingcai; Shi, Conglei; Qu, Huamin; Cui, Weiwei

    2016-02-24

    Stacked graphs have been widely adopted in various fields, because they are capable of hierarchically visualizing a set of temporal sequences as well as their aggregation. However, because of visual illusion issues, connections between overly-detailed individual layers and overly-generalized aggregation are intercepted. Consequently, information in this area has yet to be fully excavated. Thus, we present PieceStack in this paper, to reveal the relevance of stacked graphs in understanding intrinsic details of their displayed shapes. This new visual analytic design interprets the ways through which aggregations are generated with individual layers by interactively splitting and re-constructing the stacked graphs. A clustering algorithm is designed to partition stacked graphs into sub-aggregated pieces based on trend similarities of layers. We then visualize the pieces with augmented encoding to help analysts decompose and explore the graphs with respect to their interests. Case studies and a user study are conducted to demonstrate the usefulness of our technique in understanding the formation of stacked graphs.

  15. Eye lens membrane junctional microdomains: a comparison between healthy and pathological cases

    Energy Technology Data Exchange (ETDEWEB)

    Buzhynskyy, Nikolay; Scheuring, Simon [Institut Curie, Equipe Inserm Avenir, UMR168-CNRS, 26 Rue d' Ulm, 75248 Paris Cedex 05 (France); Sens, Pierre [ESPCI, CNRS-UMR 7083, 75231 Paris (France); Behar-Cohen, Francine, E-mail: simon.scheuring@curie.fr [UMRS Inserm 872, Universite Paris Descartes, Centre de Recherches des Cordeliers, 15 rue de l' Ecole de Medecine, 75270 Paris Cedex 06 (France)

    2011-08-15

    The eye lens is a transparent tissue constituted of tightly packed fiber cells. To maintain homeostasis and transparency of the lens, the circulation of water, ions and metabolites is required. Junctional microdomains connect the lens cells and ensure both tight cell-to-cell adhesion and intercellular flow of fluids through a microcirculation system. Here, we overview membrane morphology and tissue functional requirements of the mammalian lens. Atomic force microscopy (AFM) has opened up the possibility of visualizing the junctional microdomains at unprecedented submolecular resolution, revealing the supramolecular assembly of lens-specific aquaporin-0 (AQP0) and connexins (Cx). We compare the membrane protein assembly in healthy lenses with senile and diabetes-II cataract cases and novel data of the lens membranes from a congenital cataract. In the healthy case, AQP0s form characteristic square arrays confined by connexons. In the cases of senile and diabetes-II cataract patients, connexons were degraded, leading to malformation of AQP0 arrays and breakdown of the microcirculation system. In the congenital cataract, connexons are present, indicating probable non-membranous grounds for lens opacification. Further, we discuss the energetic aspects of the membrane organization in junctional microdomains. The AFM hence becomes a biomedical nano-imaging tool for the analysis of single-membrane protein supramolecular association in healthy and pathological membranes.

  16. Eye lens membrane junctional microdomains: a comparison between healthy and pathological cases

    Science.gov (United States)

    Buzhynskyy, Nikolay; Sens, Pierre; Behar-Cohen, Francine; Scheuring, Simon

    2011-08-01

    The eye lens is a transparent tissue constituted of tightly packed fiber cells. To maintain homeostasis and transparency of the lens, the circulation of water, ions and metabolites is required. Junctional microdomains connect the lens cells and ensure both tight cell-to-cell adhesion and intercellular flow of fluids through a microcirculation system. Here, we overview membrane morphology and tissue functional requirements of the mammalian lens. Atomic force microscopy (AFM) has opened up the possibility of visualizing the junctional microdomains at unprecedented submolecular resolution, revealing the supramolecular assembly of lens-specific aquaporin-0 (AQP0) and connexins (Cx). We compare the membrane protein assembly in healthy lenses with senile and diabetes-II cataract cases and novel data of the lens membranes from a congenital cataract. In the healthy case, AQP0s form characteristic square arrays confined by connexons. In the cases of senile and diabetes-II cataract patients, connexons were degraded, leading to malformation of AQP0 arrays and breakdown of the microcirculation system. In the congenital cataract, connexons are present, indicating probable non-membranous grounds for lens opacification. Further, we discuss the energetic aspects of the membrane organization in junctional microdomains. The AFM hence becomes a biomedical nano-imaging tool for the analysis of single-membrane protein supramolecular association in healthy and pathological membranes.

  17. Simulation of Impinging Cooling Performance with Pin Fins and Mist Cooling Adopted in a Simplified Gas Turbine Transition Piece

    OpenAIRE

    Tao Xu; Hang Xiu; Junlou Li; Haichao Ge; Qing Shao; Guang Yang; Zhenglei Yu

    2014-01-01

    The gas turbine transition piece was simplified to a one-four cylinder double chamber model with a single row of impinging holes in the outer wall. Heat transfer augmentation in the coolant chamber was achieved through the use of pin fin structure and mist cooling, which could increase the turbulence and heat transfer efficiency. The present research is focused on heat transfer and pressure characteristics of the impinging cooling in the coolant chamber using FLUENT software. With the given d...

  18. Primary intraocular lens implantation for penetrating lens trauma in Africa.

    Science.gov (United States)

    Bowman, R J; Yorston, D; Wood, M; Gilbert, C; Foster, A

    1998-09-01

    This study aimed to audit the surgical strategy of primary posterior chamber intraocular lens implantation for cases of recent penetrating trauma involving the lens in an African population. Retrospective, noncomparative case series. Seventy-two cases are reported, including all patients who underwent primary intraocular lens implantation for traumatic cataract extraction performed within 1 month of injury between 1988 and 1996. Demographic characteristics and follow-up attendance rates are analyzed. Surgical technique and the occurrence of intraoperative and postoperative complications are reported. Visual outcomes are reported with detailed analysis for cases of poor visual outcome. Mean age was 14.3 years (standard deviation = 11.1), 57 (79%) were male and 15 (21%) were female (chi-square = 23.66, P capsule had been breached by the trauma in 27 (38%) cases, and 15 of these required anterior vitrectomy. Capsular fixation of the implant was achieved in 49% of patients, the remainder having sulcus fixation. Intraoperative rupture of the posterior capsule occurred in four cases. The only common postoperative complication was acute fibrinous anterior uveitis, which occurred in 29 (40%) patients, and 32% of patients followed up for at least 6 months required secondary posterior capsulotomy. This was more common in younger patients (chi-square = 4.2, P < 0.05). Corrected postoperative visual acuities were available for 51 patients, of which 71% achieved 20/60 or better visual acuity. Patients 6 years of age or younger were less likely to achieve 20/60 (chi-square = 6.61, P = 0.01). This surgical strategy has proved successful, producing good visual results and causing no sight-threatening complications. Primary posterior capsulotomy may be appropriate for younger patients.

  19. Y-piece temperature and humidification during mechanical ventilation.

    Science.gov (United States)

    Solomita, Mario; Daroowalla, Feroza; Leblanc, Deniese S; Smaldone, Gerald C

    2009-04-01

    Practitioners often presume there is adequate humidification in the ventilator circuit if the Y-piece is at a specified temperature, but control of Y-piece temperature may be inadequate to ensure adequate humidification. In an in vitro bench model we measured water-vapor delivery with several heated humidification setups and a wide range of minute volume (V (E)) values. The setup included a condenser, hygrometry, and thermometer. First, we calibrated the system with a point-source humidifier and water pump. Then we tested the water-vapor delivery during non-heated-wire humidification and during heated-wire humidification with a temperature gradient of +3 degrees C, 0 degrees C, and -3 degrees C between the humidifier and the Y-piece. We compared the results to 2 recommended humidification values: 100% saturated (absolute humidity 44 mg H(2)O/L) gas at 37 degrees C (saturated/37 degrees C); and 75% saturated (absolute humidity 33 mg H(2)O/L), which is the humidity recommended by the International Organization for Standardization (the ISO standard). In all the experiments the setup was set to provide 35 degrees C at the Y-piece. Our method for measuring water-vapor delivery closely approximated the amount delivered by a calibrated pump, but slightly underestimated the water-vapor delivery in all the experiments and the whole V (E) range. At all V (E) values, water-vapor delivery during non-heated-wire humidification matched or exceeded saturated/37 degrees C and was significantly greater than that during heated-wire humidification. During heated-wire humidification, water-vapor delivery varied with the temperature gradient and did not reach saturated/37 degrees C at V (E) > 6 L/min. Water-vapor delivery with the negative temperature gradient was below the ISO standard. Maintaining temperature at one point in the inspiratory circuit (eg, Y-piece), does not ensure adequate water-vapor delivery. Other factors (humidification system, V (E), gradient setting) are critical

  20. Single Value Devices

    NARCIS (Netherlands)

    Mader, Angelika H.; Dertien, Edwin Christian; Reidsma, Dennis

    2011-01-01

    We live in a world of continuous information overflow, but the quality of information and communication is suffering. Single value devices contribute to the information and communication quality by fo- cussing on one explicit, relevant piece of information. The information is decoupled from a

  1. Single Value Devices

    NARCIS (Netherlands)

    Mader, Angelika H.; Dertien, Edwin Christian; Reidsma, Dennis; Camurri, Antonio; Costa, Cristina

    We live in a world of continuous information overflow, but the quality of information and communication is suffering. Single value devices contribute to information and communication quality by focussing on one explicit, relevant piece of information. The information is decoupled from a computer and

  2. Single Value Devices

    NARCIS (Netherlands)

    Mader, Angelika H.; Reidsma, Dennis; Dertien, Edwin Christian; Volpe, G; Kolkmeier, Jan; Camurri, A.; Kolkmeier, Jan; Nijholt, Antinus

    2015-01-01

    We live in a world of continuous information overflow, but the quality of information and communication is suffering. Single value devices contribute to the information and communication quality by focussing on one explicit, relevant piece of information. The information is decoupled from a computer

  3. A Class I (Senofilcon A) Soft Contact Lens Prevents UVB-Induced Ocular Effects, Including Cataract, in the Rabbit In Vivo

    Science.gov (United States)

    Lin, Li-Ren; Leverenz, Victor R.; Dang, Loan

    2011-01-01

    Purpose. UVB radiation from sunlight is known to be a risk factor for human cataract. The purpose in this study was to investigate the ability of a class I UV-blocking soft contact lens to protect against UVB-induced effects on the ocular tissues of the rabbit in vivo. Methods. Eyes of rabbits were exposed to UVB light for 30 minutes (270–360 nm, peak at 310 nm, 1.7 mW/cm2 on the cornea). Eyes were irradiated in the presence of either a UV-blocking senofilcon A contact lens, a minimally UV-blocking lotrafilcon A contact lens, or no contact lens at all. Effects on the cornea and lens were evaluated at various times after exposure. Results. Eyes irradiated with no contact lens protection showed corneal epithelial cell loss plus lens epithelial cell swelling, vacuole formation, and DNA single-strand breaks, as well as lens anterior subcapsular opacification. The senofilcon A lens protected nearly completely against the UVB-induced effects, whereas the lotrafilcon A lens showed no protection. Conclusions. The results indicate that use of a senofilcon A contact lens is beneficial in protecting ocular tissues of the rabbit against the harmful effects of UVB light, including photokeratitis and cataract. PMID:21421866

  4. Research on one manual zoom liquid lens

    Science.gov (United States)

    Zhao, Cunhua; Shi, Yongpeng; Li, Wenjiao; Li, Congcong

    2011-11-01

    In liquid zoom lens, the accurate fixed-focus location needs the accurate calculation of focal length. That is to say, the accurate calculation of surface curvature must be obtained. Therefore, the research of their relation in liquid zoom lens becomes extremely important which has a directly theoretical instruction for the design of liquid zoom lenses. In our paper, the relation is studied. A manual liquid lens is reported which has upper and nether components with specificaton Φ12×5mm. The zoom lens is obtained by the upper component circumvolving down into the nether components.

  5. Numerical analyses of planer plasmonic focusing lens

    Science.gov (United States)

    Chou, Yen-Yu; Lee, Yeeu-Chang

    2018-03-01

    The use of polystyrene (PS) sphere lithography has been widely applied in the fabrication of micron and nano structures, due to their low cost and ease of fabrication in large scale applications. This study evaluated the feasibility of plasmonic lens base on metal thin films with nanohole structures fabricated by using PS sphere lithography through three-dimensional (3D) finite difference time domain (FDTD) method. We calculated the intensity profile of lens with various wavelength of incident light, lens size, cutting positions, diameters of nanohole, and periods of nanohole to investigate the geometric parameters influence on the focusing properties of the plasmonic lens.

  6. Exchange of tears under a contact lens is driven by distortions of the contact lens.

    Science.gov (United States)

    Maki, Kara L; Ross, David S

    2014-12-01

    We studied the flow of the post-lens tear film under a soft contact lens to understand how the design parameters of contact lenses can affect ocular health. When a soft contact lens is inserted, the blinking eyelid causes the lens to stretch in order to conform to the shape of the eye. The deformed contact lens acts to assume its un-deformed shape and thus generates a suction pressure in the post-lens tear film. In consequence, the post-lens tear fluid moves; it responds to the suction pressure. The suction pressure may draw in fresh fluid from the edge of the lens, or it may eject fluid there, as the lens reassumes its un-deformed shape. In this article, we develop a mathematical model of the flow of the post-lens tear fluid in response to the mechanical suction pressure of a deformed contact lens. We predict the amount of exchange of fluid exchange under a contact lens and we explore the influence of the eye's shape on the rate of exchange of fluid. © The Author 2014. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

  7. New progress on monolithic X-ray lens in diffraction application

    International Nuclear Information System (INIS)

    Li Yude; He Yejun; Chen Jun; Luo Ping; Wang Dachun; Yan Yiming

    1999-12-01

    The basic physical properties for monolithic X-ray lens are introduced. The X-ray diffraction for macromolecular crystallography using monolithic X-ray lens were investigated. The experimental results show that in the same X-ray source power the diffracted intensity in the condition with X-ray lens was increased about 7 times, and the resolution was improved by 0.2 x 10 -10 -0.6 x 10 -10 m. The signal to noise ratio was also improved, and the time of measurement was reduced. The X-ray diffraction of Au thin films on the Si(100) single crystal substrates were investigated in a X-ray powder diffractometer. The experimental results show that in the same X-ray source power the diffracted intensity in the condition with X-ray lens was increased about 2 times, and the angular resolution of the diffractometer was enhanced

  8. The impact of mechanical properties of rock to the collision of rock piece

    Directory of Open Access Journals (Sweden)

    Borut Macuh

    2007-06-01

    Full Text Available The paper presents the analytical solution of the rock piece motion considering influences of geometrical and mechanical characteristics of rock mass on the arbitrary slope. The main objective of the paper is to determine the motion of the rock piece considering possibility of rock piece failure due to collision. Brief description of the analytical solution of the rock piece motion on a steep slope is given. The laboratory tests were performed to determine uniaxial compressive strength and elastic properties of the considered rock mass. Further, velocities that cause rock piece failure were determined. These maximum velocities indirectly belong to certain mass of rock piece and can be lower than velocities calculated in rock-fall analysis for certain slope geometry. Consequently, the energy magnitude is limited, because at certain velocity and mass of rock piece bigger pieces crash at collision.

  9. Surface topography of parallel grinding process for nonaxisymmetric aspheric lens

    International Nuclear Information System (INIS)

    Zhang Ningning; Wang Zhenzhong; Pan Ri; Wang Chunjin; Guo Yinbiao

    2012-01-01

    Workpiece surface profile, texture and roughness can be predicted by modeling the topography of wheel surface and modeling kinematics of grinding process, which compose an important part of precision grinding process theory. Parallel grinding technology is an important method for nonaxisymmetric aspheric lens machining, but there is few report on relevant simulation. In this paper, a simulation method based on parallel grinding for precision machining of aspheric lens is proposed. The method combines modeling the random surface of wheel and modeling the single grain track based on arc wheel contact points. Then, a mathematical algorithm for surface topography is proposed and applied in conditions of different machining parameters. The consistence between the results of simulation and test proves that the algorithm is correct and efficient. (authors)

  10. Eight piece quadrupole magnet, method for aligning quadrupole magent pole tips

    Energy Technology Data Exchange (ETDEWEB)

    Jaski, Mark S.; Liu, Jie; Donnelly, Aric T.; Downey, Joshua S.; Nudell, Jeremy J.; Jain, Animesh

    2018-01-30

    The invention provides an alternative to the standard 2-piece or 4-piece quadrupole. For example, an 8-piece and a 10-piece quadrupole are provided whereby the tips of each pole may be adjustable. Also provided is a method for producing a quadrupole using standard machining techniques but which results in a final tolerance accuracy of the resulting construct which is better than that obtained using standard machining techniques.

  11. Dual mode fuel injector with one piece needle valve member

    Science.gov (United States)

    Lawrence, Keith E.; Hinrichsen, Michael H.; Buckman, Colby

    2005-01-18

    A fuel injector includes a homogenous charge nozzle outlet set and a conventional nozzle outlet set controlled respectively by inner and outer needle value members. The homogenous charged nozzle outlet set is defined by an outer needle value member that is moveably positioned in an injector body, which defines the conventional nozzle outlet set. The inner needle valve member is positioned in the outer needle valve member. The outer needle valve member is a piece component that includes at least one external guide surface, an external value surface and an internal valve seat.

  12. Electrification: Connecting the Pieces in the Broader View

    Energy Technology Data Exchange (ETDEWEB)

    Gearhart, Chris C [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-11-28

    Presented at the SELECT Annual Meeting on September 26, 2017, this PowerPoint presentation gives an overview of connectivity and automation and how these new technologies will impact society in both known and unknown ways. Electrification challenges and opportunities are also outlined as without electrification, connectivity and automation will just magnify the negative health, climate and economic problems of the current transportation systems. Electrification can provide benefits while mitigating the negative consequences. And with careful connection of all of the pieces from materials up through controls, a sustainable transportation eco-system is attainable.

  13. [Acanthamoeba isolation from contact lens solution of contact lens wearers without keratitis].

    Science.gov (United States)

    Watanabe, R; Ishibashi, Y; Hommura, S; Ishii, K

    1994-05-01

    Acanthamoeba keratitis seems to be associated with wearing contact lenses. As controls, we surveyed contact lens wearers without keratitis. Contact lens solutions of 93 persons were examined in order to identify risk factors for contamination by Acanthamoeba. Therefore, the contact lens disinfection system and storage schedules were studied in each case. Acanthamoeba organisms were isolated from 4 specimens (4.3%). The incidence of Acanthamoeba was higher in specimens of soft contact lens solution than in those of hard contact lens solution, and all the Acanthamoeba positive cases had been using tap water.

  14. Primary anterior chamber intraocular lens for the treatment of severe crystalline lens subluxation.

    Science.gov (United States)

    Hoffman, Richard S; Fine, I Howard; Packer, Mark

    2009-10-01

    Subluxated cataractous and clear lenses are commonly treated by limbal or pars plana lensectomy followed by primary or secondary intraocular lens (IOL) implantation. Adjunctive capsular prosthetic devices have facilitated lens removal and IOL centration in these challenging cases but have also added complexity and potential complications to the procedure. Although crystalline lens extraction may be required to clear the visual axis in mild to moderate lens subluxations, we propose insertion of a primary anterior chamber IOL without lens extraction in severe subluxations when the eye is optically aphakic or can be made functionally aphakic following neodymium:YAG laser zonulysis. Two cases demonstrating this approach are presented.

  15. Protection of the eye lens

    International Nuclear Information System (INIS)

    2015-01-01

    The limit of radiation exposure for eye lens is going to decrease dramatically from 150 to 20 mSv as a transposition into the French law of a CIPR (International Commission for Radiation Protection) directive. Sanitary studies have shown that radiologists are more likely by a factor of 3.8 to get eye lens opacities than the rest of the population. The wearing of protective glasses is recommended and in order to get a better monitoring of the radiation dose new dosimeters have been designed, they can be worn on the glass frame of directly stuck on the skin near the eyes. A study has shown that veterinary surgeons that are accustomed to stay near animals to keep them quiet during radiological exams are prone to receive high doses as well as physicians that use hypnosis to decrease the level of anxiety of their patients during radiological exams. Radiation exposure of radiologists can be mitigated through: the use of protective shields and equipment and the optimization of the dose delivered to the patient. (A.C.)

  16. Non-contact optical measurement of lens capsule thickness during simulated accommodation

    Science.gov (United States)

    Ziebarth, Noel; Manns, Fabrice; Acosta, Ana-Carolina; Parel, Jean-Marie

    2005-04-01

    Purpose: To non-invasively measure the thickness of the anterior and posterior lens capsule, and to determine if it significantly changes during accommodation. Methods: Anterior and posterior capsule thickness was measured on post-mortem lenses using a non-contact optical system using a focus-detection technique. The optical system uses a 670nm laser beam delivered to a single-mode fiber coupler. The output of the fiber coupler is focused on the tissue surface using an aspheric lens (NA=0.68) mounted on a translation stage with a motorized actuator. Light reflected from the sample surface is collected by the fiber coupler and sent to a photoreceiver connected to a computer-controlled data acquisition system. Optical intensity peaks are detected when the aspheric lens is focused on the capsule boundaries. The capsule thickness is equal to the distance traveled between two peaks multiplied by the capsule refractive index. Anterior and posterior lens capsule thickness measurements were performed on 18 cynomolgus (age average: 6+/-1 years, range: 4-7 years) eyes, 1 rhesus (age: 2 years) eye, and 12 human (age average: 65+/-16, range: 47-92) eyes during simulated accommodation. The mounted sample was placed under the focusing objective of the optical system so that the light was incident on the center pole. Measurements were taken of the anterior lens capsule in the unstretched and the stretched 5mm states. The lens was flipped, and the same procedure was performed for the posterior lens capsule. Results: The precision of the optical system was determined to be +/-0.5um. The resolution is 4um and the sensitivity is 52dB. The human anterior lens capsule thickness was 6.0+/-1.2um unstretched and 4.9+/-0.9um stretched (p=0.008). The human posterior lens capsule was 5.7+/-1.2um unstretched and 5.7+/-1.4um stretched (p=0.974). The monkey anterior lens capsule thickness was 5.9+/-1.9um unstretched and 4.8+/-1.0um stretched (p=0.002). The monkey posterior lens capsule was 5

  17. Color corrected Fresnel lens for solar concentration

    International Nuclear Information System (INIS)

    Kritchman, E.M.

    1979-01-01

    A new linear convex Fresnel lens with its groove side down is described. The design philosophy is similar to the highly concentrating two focal Fresnel lens but including a correction for chromatic aberration. A solar concentration ratio as high as 80 is achieved. For wide acceptance angles the concentration nears the theoretical maximum. (author)

  18. Modified suturing contact lens for penetrating keratoplasty.

    Science.gov (United States)

    Kramer, S G; Stewart, H L

    1978-11-01

    The authors have previously described a suturing contact lens that protects the corneal endothelium by aiding in the maintenance of the anterior chamber during penetrating keratoplasty. This report describes structural modifications of the suturing contact lens, which improve its stability and effectiveness. An additional configuration for use in corneal lacerations is presented.

  19. Charged black lens in de Sitter space

    Science.gov (United States)

    Tomizawa, Shinya

    2018-02-01

    We obtain a charged black lens solution in the five-dimensional Einstein-Maxwell-Chern-Simons theory with a positive cosmological constant. It is shown that the solution obtained here describes the formation of a black hole with the spatial cross section of a sphere from that of the lens space of L (n ,1 ) in five-dimensional de Sitter space.

  20. [Iris hooks and modified capsular tension ring for subluxation lens in patients with Marfan's syndrome].

    Science.gov (United States)

    Wu, Wen-Jie; Zheng, Dan-ying; Zheng, Ying-feng; Cai, Xiao-yu

    2007-02-01

    To evaluate clinical efficiency and safety of the iris hooks and modified capsular tension ring (MCTR) for the treatment of subluxation lens in patients with Marfan's syndrome. This study comprised 5 patients (7 eyes) with Marfan's syndrome and subluxation lens. After 3.2 mm clear cornea incision and continuous curvilinear capsulorhexis (CCC), 2 - 4 disposable nylon iris hooks were inserted through the stab incisions and placed in the capsulorhexis to support the capsule and enlarged the CCC. Following irrigation/aspiration, a MCTR with suture in its eyelet was placed in the capsule bag. After tightening and tying the suture of MCTR, the capsular bag was centered and fixed. A foldable AcrySof one-piece intraocular lens (IOL) was then placed in the capsule bag. Twelve months after the operation, the best corrected visual acuity was >/= 0.8 in six eyes and 0.7 in one eye. The scheimpflug images obtained from the Pentacam demonstrated that the IOL were well centered. UBM showed that all the MCTR and the haptics of the IOL were in the capsule bag, the eyelet of the MCTR was rested stably between the capsulorhexis margin and the iris. The retroillumination photograph indicated that only one eye had obvious posterior capsular opacification. No intraoperative and postoperative complications such as prolapse of vitreous and retina detachment was occurred. The iris hooks can provide excellent intraoperative capsule-lens stability and facilitate the manipulation during operation. MCTR allows additional suture fixation to the eye wall without damaging the capsular bag and maintains the long-term stability of the intraocular lens. Furthermore, MCTR is helpful for avoiding dislocation of the IOL due to progressive weakening of the zonular fibers in some patients and provides long-term safety.

  1. Contact Lens Use in the Civil Airman Population

    National Research Council Canada - National Science Library

    Nakagawara, Van

    2002-01-01

    ...) aeromedical certificate. Although contact lens technology has advanced dramatically in recent years, the aviation environment may still have adverse effects on contact lens performance in some flight situations...

  2. Corrected electrostatic lens systems for ion beams

    International Nuclear Information System (INIS)

    Dalgish, R.L.

    1981-01-01

    Recent work in our laboratory has introduced a new class of electrostatic focus forming element for beams, the ELCO lens. It compares favourably with the electrostatic and magnetic quadrupole elements conventionally used for microbeam formation. The ELCO lens does however have disadvantages associated with apertures and alignment. We have continued with the development of ion beam lenses and have evolved a further class of lens element which eliminates aperture and alignment problems. This new element can be combined like optical lenses into an aberration corrected system. Experimental measurement on the basic lens element has confirmed mathematical analysis of ion trajectories through the element. This mathematical analysis predicts that the basic element can be combined into a corrected lens system for, either: (1) high resolution microprobe formation with intrinsic rastering ability, the spot size limited only by the beam properties; or (2) high quality image formation with large magnification/demagnification ratio and wide angular aperture. (orig.)

  3. Biomechanical evaluation of one-piece and two-piece small-diameter dental implants: In-vitro experimental and three-dimensional finite element analyses.

    Science.gov (United States)

    Wu, Aaron Yu-Jen; Hsu, Jui-Ting; Chee, Winston; Lin, Yun-Te; Fuh, Lih-Jyh; Huang, Heng-Li

    2016-09-01

    Small-diameter dental implants are associated with a higher risk of implant failure. This study used both three-dimensional finite-element (FE) simulations and in-vitro experimental tests to analyze the stresses and strains in both the implant and the surrounding bone when using one-piece (NobelDirect) and two-piece (NobelReplace) small-diameter implants, with the aim of understanding the underlying biomechanical mechanisms. Six experimental artificial jawbone models and two FE models were prepared for one-piece and two-piece 3.5-mm diameter implants. Rosette strain gauges were used for in-vitro tests, with peak values of the principal bone strain recorded with a data acquisition system. Implant stability as quantified by Periotest values (PTV) were also recorded for both types of implants. Experimental data were analyzed statistically using Wilcoxon's rank-sum test. In FE simulations, the peak value and distribution of von-Mises stresses in the implant and bone were selected for evaluation. In in-vitro tests, the peak bone strain was 42% lower for two-piece implants than for one-piece implants. The PTV was slightly lower for one-piece implants (PTV = -6) than for two-piece implants (PTV = -5). In FE simulations, the stresses in the bone and implant were about 23% higher and 12% lower, respectively, for one-piece implants than those for two-piece implants. Due to the higher peri-implant bone stresses and strains, one-piece implants (NobelDirect) might be not suitable for use as small-diameter implants. Copyright © 2016. Published by Elsevier B.V.

  4. Cooling profile following prosthetic preparation of 1-piece dental implants.

    Science.gov (United States)

    Cohen, Omer; Gabay, Eran; Machtei, Eli E

    2010-01-01

    The aim of this study was to evaluate the effect of water irrigation on heat dissipation kinetics following abutment preparation of 1-piece dental implants. UNO 1-piece dental implants were mounted on Plexiglas apparatus clamping the implant at the collar. T-type thermocouple was attached to the first thread of the implant and recorded thermal changes at 100 millisecond intervals. Implants were prepared using highspeed dental turbine at 400,000 RPM with a coarse diamond bur. Once temperature reached 47 degrees C, abutment preparation was discontinued. Thirty implants were divided into 2 groups. Group A: Passive cooling without water irrigation. Group B: Cooling with turbine's water spray adjacent to the implant (30 mL/min). The following parameters were measured: T47 (time from peak temperature to 47 degrees C), T50%, T75% (time until the temperature amplitude decayed by 50% and 75%, respectively), dTemp50%/dt decay, and dTemp75%/dt decay (cooling rate measured at 50% and 75% of amplitude decay, respectively). Water spray irrigation significantly reduced T47 (1.37+/-0.29 seconds vs 19.97+/-3.06 seconds, Pspray irrigation also increased cooling capacity ninefold: dTemp50%/dt decay (4.14+/-0.61 degrees C/s vs 0.48+/-0.06 degrees C/s, Pspray adjacent to the abutment following the cessation of implant preparation might prove beneficial for rapid cooling of the implant.

  5. Noncontact optical measurement of lens capsule thickness ex vivo

    Science.gov (United States)

    Ziebarth, Noel M.; Manns, Fabrice; Uhlhorn, Stephen; Parel, Jean-Marie

    2004-07-01

    Purpose: To design a non-contact optical system to measure lens capsule thickness in cadaver eyes. Methods: The optical system uses a 670nm laser beam delivered to a single-mode fiber coupler. The output of the fiber coupler is focused onto the tissue using an aspheric lens (NA=0.68) mounted on a motorized translation stage. Light reflected from the sample is collected by the fiber coupler and sent to a silicon photodiode connected to a power meter. Peaks in the power signal are detected when the focal point of the aspheric lens coincides with the capsule boundaries. The capsule thickness is proportional to the distance between successive peaks. Anterior and posterior lens capsule thickness measurements were performed on 13 human, 10 monkey, and 34 New Zealand white rabbit lenses. The cadaver eyes were prepared for optical measurements by bonding a PMMA ring on the sclera. The posterior pole was sectioned, excess vitreous was removed, and the eye was placed on a Teflon slide. The cornea and iris were then sectioned. After the experiments, the lenses were excised, placed in 10% buffered formalin, and prepared for histology. Results: Central anterior lens capsule thickness was 9.4+/-2.9μm (human), 11.2+/-6.6μm (monkey), and 10.3+/-3.6μm (rabbit) optically and 14.9+/-1.6μm (human), 17.7+/-4.9μm (monkey), and 12.6+/-2.3μm (rabbit) histologically. The values for the central posterior capsule were 9.4+/-2.9μm (human), 6.6+/-2.5μm (monkey), and 7.9+/-2.3μm (rabbit) optically and 4.6+/-1.4μm (human), 4.5+/-1.2μm (monkey), and 5.7+/-1.7μm (rabbit) histologically. Conclusions: This study demonstrates that a non-contact optical system can successfully measure lens capsule thickness in cadaver eyes.

  6. Investigation of lens morphology and mechanical characteristics of lens capsule and lens nucleus in patients with agerelated and diabetic cataract

    Directory of Open Access Journals (Sweden)

    A. S. Tishkova

    2014-07-01

    Full Text Available Purpose: To investigate the influence of carbohydrate metabolism on the structure and mechanical properties of the lens capsule and nucleus.Methods: Human lens pathology was studied in different forms of cataract. 220 patients with a cataract (220 eyes were included in this study. Morphological, immunohystological and immunocytochemical investigations of lens substance (antibodies to a- (a-А and a-В, b-, g- crystallines, spectroscopic analyses of smears and morphometric analyses of slices, investigation of lens morphology and mechanical caracteristics of lens capsule and lens nucleus were performed.Results: The capsule of the lens in patients with senile cataract contains more Na+, Cl-. The capsule of the lens in patients with senile cataract contains more Ca2+, O. Mechanical strength of the capsule in the case of diabetes mellitus was lower comparatively with senile cataract in the same age groups. More significant expression of a-В and b-crystallines was found in patients with diabetes mellitus comparatively with patients with age-related cataract. Morphological features were founded in patients with cortical and nuclear forms of senile cataract and the diabetic cataract.Conclusion: During surgery (ultrasonic microcoaxial phacoemulsification the equivalent of ultrasound was recorded. Lower density of the lens nucleus of patients with diabetes mellitus made it possible to use lower energy parameters. Using the torsion ultrasound in those cases allowed us to decrease the influence of ultrasound on eye tissues and reduce the time of achieving the maximum BCVA in the postsurgical period.

  7. Investigation of lens morphology and mechanical characteristics of lens capsule and lens nucleus in patients with agerelated and diabetic cataract

    Directory of Open Access Journals (Sweden)

    A. S. Tishkova

    2013-01-01

    Full Text Available Purpose: To investigate the influence of carbohydrate metabolism on the structure and mechanical properties of the lens capsule and nucleus.Methods: Human lens pathology was studied in different forms of cataract. 220 patients with a cataract (220 eyes were included in this study. Morphological, immunohystological and immunocytochemical investigations of lens substance (antibodies to a- (a-А and a-В, b-, g- crystallines, spectroscopic analyses of smears and morphometric analyses of slices, investigation of lens morphology and mechanical caracteristics of lens capsule and lens nucleus were performed.Results: The capsule of the lens in patients with senile cataract contains more Na+, Cl-. The capsule of the lens in patients with senile cataract contains more Ca2+, O. Mechanical strength of the capsule in the case of diabetes mellitus was lower comparatively with senile cataract in the same age groups. More significant expression of a-В and b-crystallines was found in patients with diabetes mellitus comparatively with patients with age-related cataract. Morphological features were founded in patients with cortical and nuclear forms of senile cataract and the diabetic cataract.Conclusion: During surgery (ultrasonic microcoaxial phacoemulsification the equivalent of ultrasound was recorded. Lower density of the lens nucleus of patients with diabetes mellitus made it possible to use lower energy parameters. Using the torsion ultrasound in those cases allowed us to decrease the influence of ultrasound on eye tissues and reduce the time of achieving the maximum BCVA in the postsurgical period.

  8. Randomized trial of the effect of contact lens wear on self-perception in children.

    Science.gov (United States)

    Walline, Jeffrey J; Jones, Lisa A; Sinnott, Loraine; Chitkara, Monica; Coffey, Bradley; Jackson, John Mark; Manny, Ruth E; Rah, Marjorie J; Prinstein, Mitchell J

    2009-03-01

    To determine whether contact lens wear affects children's self-perceptions. The Adolescent and Child Health Initiative to Encourage Vision Empowerment Study was a randomized, single-masked trial conducted at five clinical centers in the United States. Subjects were 8- to 11-year-old myopic children randomly assigned to wear spectacles (n = 237) or soft contact lenses (n = 247) for 3 years. The primary endpoint was the Self-Perception Profile for Children Global Self-Worth scale. Secondary outcomes included the Physical Appearance, Athletic Competence, Scholastic Competence, Behavioral Conduct, and Social Acceptance Self-Perception Profile for Children scales. Global self-worth was not affected by contact lens wear [analysis of variance (ANOVA), difference = 0.06; 95% CI, -0.004 to 0.117]. Physical appearance (ANOVA, difference = 0.15; 95% CI, 0.07 to 0.22), athletic competence (ANOVA, difference = 0.08; 95% CI, 0.01 to 0.15), and social acceptance (ANOVA, difference = 0.10; 95% CI, 0.03 to 0.17) were all greater for contact lens wearers. Although contact lens wear does not affect global self-perceptions of 8- to 11-year-old myopic children their physical appearance, athletic competence, and social acceptance self-perceptions are likely to improve with contact lens wear. Eye care practitioners should consider the social and visual benefits of contact lens wear when choosing the most appropriate vision correction modality for children as young as 8 years of age.

  9. DotLens smartphone microscopy for biological and biomedical applications (Conference Presentation)

    Science.gov (United States)

    Sung, Yu-Lung; Zhao, Fusheng; Shih, Wei-Chuan

    2017-02-01

    Recent advances in inkjet-printed optics have created a new class of lens fabrication technique. Lenses with a tunable geometry, magnification, and focal length can be fabricated by dispensing controlled amounts of liquid polymer onto a heated surface. This fabrication technique is highly cost-effective, and can achieve optically smooth surface finish. Dubbed DotLens, a single of which weighs less than 50 mg and occupies a volume less than 50 μL. DotLens can be attached onto any smartphone camera akin to a contact lens, and enable smartphones to obtain image resolution as fine as 1 µm. The surface curvature modifies the optical path of light to the image sensor, and enables the camera to focus as close as 2 mm. This enables microscopic imaging on a smartphone without any additional attachments, and has shown great potential in mobile point-of-care diagnostic systems, particularly for histology of tissue sections and cytology of blood cells. DotLens Smartphone Microscopy represents an innovative approach fundamentally different from other smartphone microscopes. In this paper, we describe the application and performance of DotLens smartphone microscopy in biological and biomedical research. In particular, we show recent results from images collected from pathology tissue slides with cancer features. In addition, we show performance in cytological analysis of blood smear. This tool has empowered Citizen Science investigators to collect microscopic images from various interesting objects.

  10. Zoom lens calibration with zoom- and focus-related intrinsic parameters applied to bundle adjustment

    Science.gov (United States)

    Zheng, Shunyi; Wang, Zheng; Huang, Rongyong

    2015-04-01

    A zoom lens is more flexible for photogrammetric measurements under diverse environments than a fixed lens. However, challenges in calibration of zoom-lens cameras preclude the wide use of zoom lenses in the field of close-range photogrammetry. Thus, a novel zoom lens calibration method is proposed in this study. In this method, instead of conducting modeling after monofocal calibrations, we summarize the empirical zoom/focus models of intrinsic parameters first and then incorporate these parameters into traditional collinearity equations to construct the fundamental mathematical model, i.e., collinearity equations with zoom- and focus-related intrinsic parameters. Similar to monofocal calibration, images taken at several combinations of zoom and focus settings are processed in a single self-calibration bundle adjustment. In the self-calibration bundle adjustment, three types of unknowns, namely, exterior orientation parameters, unknown space point coordinates, and model coefficients of the intrinsic parameters, are solved simultaneously. Experiments on three different digital cameras with zoom lenses support the feasibility of the proposed method, and their relative accuracies range from 1:4000 to 1:15,100. Furthermore, the nominal focal length written in the exchangeable image file header is found to lack reliability in experiments. Thereafter, the joint influence of zoom lens instability and zoom recording errors is further analyzed quantitatively. The analysis result is consistent with the experimental result and explains the reason why zoom lens calibration can never have the same accuracy as monofocal self-calibration.

  11. Modeling internal stress distributions in the human lens: can opponent theories coexist?

    Science.gov (United States)

    Belaidi, A; Pierscionek, B K

    2007-08-03

    The effects of material properties and equatorial stretching forces on the stress distribution and shape profile of human lenses were investigated to see whether support could be found for either or both current theories of accommodation. Finite element analysis was used to create models using shape parameters and material properties from published data. Models were constructed for two lenses of different ages. Material properties were varied to show differences between models with a single elastic modulus and those with different moduli for the cortex and the nucleus. Two levels of stretching forces were applied at the equator. Comparisons between experimental and model profiles were made, and stress distribution patterns were constructed. In all models, stretching produces a flattening in the peripheral curvature of the lens. In the younger lens, model and experimental results show that central curvature at some points is steeper for stretched than for unstretched profiles. In the older lens, gradients are flatter at all central points for stretched model and experimental profiles compared to the unstretched profile. In all models, there is a region of higher stress distribution within the lens that corresponds with the position of an inflection point that appears on the anterior surface and, in the older lens, also on the posterior surface. The results show that equatorial stretching forces can produce shape changes in support of both current theories of accommodation depending on the lens age, shape, and applied force.

  12. Two-piece zirconia implants supporting all-ceramic crowns: a prospective clinical study.

    Science.gov (United States)

    Cionca, Norbert; Müller, Nada; Mombelli, Andrea

    2015-04-01

    The aim of this prospective clinical study is to evaluate the safety and efficacy of a new all-ceramic implant system to replace missing teeth in partially edentulous patients. Thirty-two partially edentulous, systemically healthy patients were treated with 49 two-piece zirconia implants (ZERAMEX(®) T Implant System). Zirconia abutments were connected with adhesive resin cement. Single-unit full-ceramic crowns were cemented. The cases have been followed for 588 ± 174 days after loading (range 369-889 days). All patients have been re-evaluated 1 year after loading. The cumulative survival rate 1 year after loading was 87% implants. All failures were the result of aseptic loosening, and no implants were lost after the first year. The results of the other cases were good, and the patients were very satisfied. The cumulative soft tissue complication rate was 0%, the cumulative technical complication rate was 4% implants, the cumulative complication rate for bone loss >2 mm was 0%, and the cumulative esthetic complication rate was 0%. Including the data from 20 patients treated with an earlier version of the system, an over-all 2-year cumulative survival rate of 86% was calculated for a total of 76 two-piece zirconia implants supporting all-ceramic crowns in 52 patients. Replacement of single teeth in the posterior area was possible with this new full-ceramic implant system. Failures were due to aseptic loosening. © 2014 The Authors. Clinical Oral Implants Research Published by John Wiley & Sons Ltd.

  13. Two-piece zirconia implants supporting all-ceramic crowns: A prospective clinical study

    Science.gov (United States)

    Cionca, Norbert; Müller, Nada; Mombelli, Andrea

    2015-01-01

    Objectives The aim of this prospective clinical study is to evaluate the safety and efficacy of a new all-ceramic implant system to replace missing teeth in partially edentulous patients. Material and methods Thirty-two partially edentulous, systemically healthy patients were treated with 49 two-piece zirconia implants (ZERAMEX® T Implant System). Zirconia abutments were connected with adhesive resin cement. Single-unit full-ceramic crowns were cemented. The cases have been followed for 588±174 days after loading (range 369–889 days). All patients have been re-evaluated 1 year after loading. Results The cumulative survival rate 1 year after loading was 87% implants. All failures were the result of aseptic loosening, and no implants were lost after the first year. The results of the other cases were good, and the patients were very satisfied. The cumulative soft tissue complication rate was 0%, the cumulative technical complication rate was 4% implants, the cumulative complication rate for bone loss >2 mm was 0%, and the cumulative esthetic complication rate was 0%. Including the data from 20 patients treated with an earlier version of the system, an over-all 2-year cumulative survival rate of 86% was calculated for a total of 76 two-piece zirconia implants supporting all-ceramic crowns in 52 patients. Conclusions Replacement of single teeth in the posterior area was possible with this new full-ceramic implant system. Failures were due to aseptic loosening. PMID:24666352

  14. Cuba Through A New Lens

    Directory of Open Access Journals (Sweden)

    Jean Stubbs

    2008-12-01

    Full Text Available [First paragraph] The Origins of the Cuban Revolution Reconsidered. Samuel Farber. Chapel Hill: University of North Carolina Press, 2006. x + 212 pp. (Paper US$ 19.95 Cuba: A New History. Ric hard Gott . New Haven: Yale University Press, 2005. xii + 384 pp. (Paper US$ 17.00 Havana: The Making of Cuban Culture. Antoni Kapcia. Oxford: Berg Publishers, 2005. xx + 236 pp. (Paper US$ 24.95 Richard Gott, Antoni Kapcia, and Samuel Farber each approach Cuba through a new lens. Gott does so by providing a broad-sweep history of Cuba, which is epic in scope, attaches importance to social as much as political and economic history, and blends scholarship with flair. Kapcia homes in on Havana as the locus for Cuban culture, whereby cultural history becomes the trope for exploring not only the city but also Cuban national identity. Farber revisits his own and others’ interpretations of the origins of the Cuban Revolution.

  15. Radiation studies in Lens culinaris

    International Nuclear Information System (INIS)

    Sinha, S.S.N.

    1977-01-01

    Estimation of chromosomal aberrations in flowers of Lens culinaris according to their sequence of development in the plants at 4, 8 and 12 Kr in the M 1 generation, showed that the later formed flowers had smaller percentages of cells with aberrations than those developed earlier. It is suggested that this may be the result of competition between more damaged and less damaged cells during the development of the shoot. There is consequently a decrease of sterility in successive flowers. The numbers of karyotypes taking part in the formation of lower and uppermost flowers were estimated cytologically at 4, 8 and 12 Kr. It was found that more karyotypes were involved in the formation of the lower flowers than in the upper ones. It appeared that at lower doses larger numbers of karyotypes were taking part in the formation of the chimaera than at higher doses. (auth.)

  16. Exome Array Analysis of Nuclear Lens Opacity.

    Science.gov (United States)

    Loomis, Stephanie J; Klein, Alison P; Lee, Kristine E; Chen, Fei; Bomotti, Samantha; Truitt, Barbara; Iyengar, Sudha K; Klein, Ronald; Klein, Barbara E K; Duggal, Priya

    2018-06-01

    Nuclear cataract is the most common subtype of age-related cataract, the leading cause of blindness worldwide. It results from advanced nuclear sclerosis, or opacity in the center of the optic lens, and is affected by both genetic and environmental risk factors, including smoking. We sought to understand the genetic factors associated with nuclear sclerosis through interrogation of rare and low frequency coding variants using exome array data. We analyzed Illumina Human Exome Array data for 1,488 participants of European ancestry in the Beaver Dam Eye Study who were without cataract surgery for association with nuclear sclerosis grade, controlling for age and sex. We performed single-variant regression analysis for 32,138 variants with minor allele frequency (MAF) ≥0.003. In addition, gene-based analysis of 11,844 genes containing at least two variants with MAF nuclear sclerosis, the possible association with the RNF149 gene highlights a potential candidate gene for future studies that aim to understand the genetic architecture of nuclear sclerosis.

  17. Microbial contamination of contact lens storage cases and domestic tap water of contact lens wearers.

    Science.gov (United States)

    Üstüntürk, Miray; Zeybek, Zuhal

    2012-11-01

    Contact lenses have been widely used as an alternative to spectacles both in developed and developing countries. However, under certain circumstances, adverse responses can occur during contact lens wear and several microorganisms--including bacteria, fungi, and free living amoebae--can cause several eye infections in wearers. Extended wear of contact lenses is the major risk factor of eye infections such as microbial keratitis, besides contaminated contact lens storage case, contaminated lens care solutions, and inaccurate contact lens handling. In this study, we collected contact lens storage case and domestic tap water samples from 50 asymptomatic contact lens wearers. We determined that total aerobic mesophilic bacteria were isolated in 45 (90 %), Gram negative rod bacteria were isolated in 20 (40 %), Pseudomonas spp. were isolated in 2 (4 %) and fungi were isolated in 18 (36 %) out of 50 contact lens storage cases. Free living amoebae were not detected in investigated contact lens storage cases. At the same time, out of 50, total aerobic mesophilic bacteria were isolated in 34 (68 %), fungi were isolated in 15 (30 %) and free living amoebae were isolated in 15 (30 %) domestic tap water samples. No Gram-negative rod bacteria and Pseudomonas spp. were detected in investigated water samples. Two contact lens case samples and two tap water samples were excluded from the analysis for Pseudomonas spp. for technical reasons. According to our findings, inadequate contact lens maintenance during lens wear may result in the contamination of contact lens storage cases. This situation can lead to severe eye infections in contact lens wearers over time.

  18. Effectiveness of one-piece implants inserted in cuspid sites.

    Science.gov (United States)

    Carinci, Francesco

    2012-12-01

    One-piece implants (OPIs) incorporate the trans-mucosal abutment facing the soft tissues as an integral part of the implant. OPIs are usually welded together and loaded immediately. Since no report focuses specifically on OPIs inserted in cuspid sites, a retrospective study is performed. Nineteen patients (10 females and 9 males) with a median age of 62 years (range, 43-80) were admitted at the Dental Clinic, University of Chieti (Italy), for evaluation and implant treatment, by one surgeon between January and December 2010. In our series, the survival rate (SVR) and success rate (SCR) were 96.8% and 100%, respectively. Statistical analysis demonstrated that no studied variable had an impact on the survival (i.e., lost implants) and clinical success (i.e., crestal bone resorption). OPIs are reliable devices for oral rehabilitation in the cuspid sites.

  19. Cutting insert and work piece materials for minimum quantity lubrication

    Science.gov (United States)

    Kurgin, Sheri; Barber, Gary; Zou, Qian

    2011-05-01

    There is considerable interest in utilizing either dry or minimum quantity lubrication (MQL) as an alternative to flood cooling due to environmental concerns with flood coolant such as excessive misting and disposal of the used coolant. Dry machining can result in high tool wear and also built up edge problems on the cutting tool. The objective of this research was to study the effect of work piece material and tool material on the machining characteristics, in this case reaming, of aluminum using MQL. In particular, a high tin casting and three different tool materials: carbide, DLC and PCD were studied. The high tin casting was found to produce lower cutting temperature and lower spindle power. The PCD coated insert performed the best in terms of lowest temperature rise, lowest spindle power and highest part quality.

  20. The RNA silencing pathway: the bits and pieces that matter.

    Directory of Open Access Journals (Sweden)

    Marian A C Groenenboom

    2005-07-01

    Full Text Available Cellular pathways are generally proposed on the basis of available experimental knowledge. The proposed pathways, however, may be inadequate to describe the phenomena they are supposed to explain. For instance, by means of concise mathematical models we are able to reveal shortcomings in the current description of the pathway of RNA silencing. The silencing pathway operates by cleaving siRNAs from dsRNA. siRNAs can associate with RISC, leading to the degradation of the target mRNA. We propose and analyze a few small extensions to the pathway: a siRNA degrading RNase, primed amplification of aberrant RNA pieces, and cooperation between aberrant RNA to trigger amplification. These extensions allow for a consistent explanation for various types of silencing phenomena, such as virus induced silencing, transgene and transposon induced silencing, and avoidance of self-reactivity, as well as for differences found between species groups.

  1. Resolving the Aerosol Piece of the Global Climate Picture

    Science.gov (United States)

    Kahn, R. A.

    2017-12-01

    Factors affecting our ability to calculate climate forcing and estimate model predictive skill include direct radiative effects of aerosols and their indirect effects on clouds. Several decades of Earth-observing satellite observations have produced a global aerosol column-amount (AOD) record, but an aerosol microphysical property record required for climate and many air quality applications is lacking. Surface-based photometers offer qualitative aerosol-type classification, and several space-based instruments map aerosol air-mass types under favorable conditions. However, aerosol hygroscopicity, mass extinction efficiency (MEE), and quantitative light absorption, must be obtained from in situ measurements. Completing the aerosol piece of the climate picture requires three elements: (1) continuing global AOD and qualitative type mapping from space-based, multi-angle imagers and aerosol vertical distribution from near-source stereo imaging and downwind lidar, (2) systematic, quantitative in situ observations of particle properties unobtainable from space, and (3) continuing transport modeling to connect observations to sources, and extrapolate limited sampling in space and time. At present, the biggest challenges to producing the needed aerosol data record are: filling gaps in particle property observations, maintaining global observing capabilities, and putting the pieces together. Obtaining the PDFs of key particle properties, adequately sampled, is now the leading observational deficiency. One simplifying factor is that, for a given aerosol source and season, aerosol amounts often vary, but particle properties tend to be repeatable. SAM-CAAM (Systematic Aircraft Measurements to Characterize Aerosol Air Masses), a modest aircraft payload deployed frequently could fill this gap, adding value to the entire satellite data record, improving aerosol property assumptions in retrieval algorithms, and providing MEEs to translate between remote-sensing optical constraints

  2. Corrosion mineralogy of an 1800 Spanish piece of eight

    International Nuclear Information System (INIS)

    Craig, J.R.; Callahan, J.E.; Kimbell, J.T.; Solberg, T.N.

    2002-01-01

    Spanish colonial eight real silver coins, commonly called Pieces of Eight, were used throughout the Spanish-speaking world for hundreds of years. We undertook a detailed mineralogical, textural, and chemical investigation of an 1800 Carlos IIII eight real coin recovered from the wreck of the Spanish frigate Santa Leocadia, which sank on the rocky shore of Ecuador on November 16, 1800, with a loss of more than 140 lives and of 2,100,000 pesos of gold and silver coins. The coin is a typical eight real piece, composed of about 90% Ag and 10% Cu. It was buried in elastic sediments beneath the oxidized zone, such that it reacted with sulfur released by sulfate-reducing bacteria. Consequently, the coin has been totally encapsulated in a mixture of sand, gravel, and shell fragments cemented by metal sulfides. The residual coin consists of silver with small interspersed micrometric grains of copper. Reaction of the dissolved metal with the bacterially generated diagenetic sulfur in the intergranular fluids resulted in extensive cementation of the sediment particles by Ag and Cu sulfides. In the 1-mm zone immediately adjacent to the coin, Cu-bearing acanthite occurs as concentric layers with intervening zones of sand and clay. Beyond this zone, acanthite formed from Ag dissolved from the coin occurs as a more or less continuous interstitial cement with local small islands of covellite, CuS. Copper also occurs as films of Cu carbonate on quartz grains, as isolated grains of jalpaite Ag 3 CuS 2 , stromeyerite AgCuS, mckinstryite (Ag,Cu) 2 S, and as atacamite Cu 2 C1(OH) 3 , which rim and replace detrital carbonate grains. (author)

  3. INTRAOCULAR LENS POSITION IN COMBINED PHACOEMULSIFICATION AND VITREORETINAL SURGERY.

    Science.gov (United States)

    Ozates, Serdar; Kiziltoprak, Hasan; Koc, Mustafa; Uzel, Mehmet Murat; Teke, Mehmet Yasin

    2017-10-09

    To assess the decentration and angle of tilt of the intraocular lens (IOL) according to the intravitreal tamponade types used in combined phacoemulsification and vitreoretinal surgery. This prospective and randomized clinical study involved 73 eyes of 69 patients who underwent combined vitreoretinal surgery. Eyes with intravitreal tamponades formed the study group and eyes without intravitreal tamponades formed the control group. The study group was further divided into silicone oil and gas tamponade subgroups. Cross-sectional IOL images were captured using a Pentacam HR (Oculus, Germany) and tilt and decentration were calculated with Adobe Photoshop software (Adobe, San Jose, CA). The mean angle of tilt and decentration at the vertical meridian were significantly higher in both tamponade groups than in the control group (P 0.05). When comparing the silicone oil and gas tamponade subgroups, no significant differences were noted on the position of IOL at both meridians (P > 0.05 for all). Intravitreal tamponades have an important effect on the position of IOL in combined vitreoretinal surgery. Silicone oil and gas tamponades may induce postoperative tilt and decentration of one-piece acrylic IOLs.

  4. Indigenous Knowledge - A Holistic View Through a Food Security Lens

    Science.gov (United States)

    Angnaboogok, V.; Behe, C.; Daniel, R. G.

    2017-12-01

    Rapid changes occurring within the Arctic heighten the need to understand the multiple drivers pushing change and their cumulative impacts. Most importantly to better understand Arctic change a holistic view is needed that can only be achieved through bringing together multiple knowledge systems and scientific disciplines. Inuit have called the Arctic home from time immemorial acquiring a knowledge system. The Inuit knowledge system continues to grow, and holds methodologies and assessment processes that provide a pathway for holistically understanding the Arctic. This holistic view is largely attributed to a focus on relationships between system components, close attention to food webs, and a unique understanding of interconnecting systems. The Alaskan Inuit understanding of food security represents an Indigenous way of viewing the world - where food security encompasses complex and interlinked cultural and environmental systems. These systems are comprised of connections among the health of people, animals, and plants; the different states of land, sea, and air; and the cultural fabric held together by language, cultural expression, and social integrity. Within the Inuit knowledge system, it is impossible to disentangle some of these relationships; when we discuss an Inuit food security perspective, it is this interconnectivity and these relationships that we refer to. This presentation will offer an introduction to what it means to adopt a food security lens approach - a view needed to build our knowledge of the changes that are occurring and further our understanding of cumulative impacts while illuminating the nexus between all pieces that make up Arctic ecosystems.

  5. Motorized injector-assisted intrascleral intraocular lens fixation.

    Science.gov (United States)

    Hung, Jia-Horung; Wang, Shih-Hao; Teng, Yu-Ti; Hsu, Sheng-Min

    2017-03-01

    For eyes with deficient capsular support, intraocular lens (IOL) implantation has long been a technical challenge. Recently, intrascleral fixation of the haptics of a three-piece posterior chamber IOL has become a popular option. In this procedure, externalization of the leading haptic during IOL injection is a stressful step. We present a modified technique to improve the ease and safety of this step. Our modified technique involves IOL injection with a motorized injector with several important modifications described here. With these modifications, a surgeon can easily maintain the correct orientation of the IOL in a well-controlled manner during IOL injection. The records of 13 patients who underwent this technique were retrospectively evaluated. Corrected-distance visual acuity improved significantly after surgery (pIOL decentration, or vitreous hemorrhage was noted during the follow-up period. In conclusion, the motorized injector-assisted intrascleral IOL fixation technique is a safe and effective alternative to the conventional procedure. This technique makes the process of leading haptic externalization easier and more controllable. Copyright © 2017. Published by Elsevier Taiwan.

  6. Motorized injector-assisted intrascleral intraocular lens fixation

    Directory of Open Access Journals (Sweden)

    Jia-Horung Hung

    2017-03-01

    Full Text Available For eyes with deficient capsular support, intraocular lens (IOL implantation has long been a technical challenge. Recently, intrascleral fixation of the haptics of a three-piece posterior chamber IOL has become a popular option. In this procedure, externalization of the leading haptic during IOL injection is a stressful step. We present a modified technique to improve the ease and safety of this step. Our modified technique involves IOL injection with a motorized injector with several important modifications described here. With these modifications, a surgeon can easily maintain the correct orientation of the IOL in a well-controlled manner during IOL injection. The records of 13 patients who underwent this technique were retrospectively evaluated. Corrected-distance visual acuity improved significantly after surgery (p<0.05. No postoperative retinal detachment, endophthalmitis, IOL decentration, or vitreous hemorrhage was noted during the follow-up period. In conclusion, the motorized injector-assisted intrascleral IOL fixation technique is a safe and effective alternative to the conventional procedure. This technique makes the process of leading haptic externalization easier and more controllable.

  7. Contact lens compliance among a group of young, university-based lens users in South India.

    Science.gov (United States)

    Noushad, Babu; Saoji, Yeshwant; Bhakat, Premjit; Thomas, Jyothi

    2012-01-01

    To investigate the rate of compliance with the soft contact lens care and maintenance procedures with a focus on contact lens wearing habits, cleaning and disinfecting procedures, and maintenance of lens care accessories in a group of young, university-based contact lens wearers Two hundred and sixteen young soft contact lens wearers with an age range of 18-22 years were selected conveniently from the student population of Manipal University, Manipal, India. After receiving informed consent from the participants, their level of compliance with contact lenses was assessed using a questionnaire. The mean (±SD) age of the participants was 21.86±2.35 years. Out of 216 subjects, only 34% of the lens users were identified to be compliant with the least level of compliance observed in the maintenance of lens care accessories. Conventional users showed significantly (p=0.001) better level of compliance compared to disposable wearers and so did the users who acquired their lenses from clinicians (p=0.001) compared to over-the-counter lens receipt. The gender (p=0.496) and years of experience in contact lens use (p=0.142) did not show any statistically significant difference in the level of compliance. This study demonstrated that non-compliance with lens care procedures among a group of young, university-based soft contact lens wearers is common. The results indicated that all subjects had some degree of non-compliance and the least level of compliance observed in the care of lens accessories.

  8. Tear film physiology and contact lens wear. II. Contact lens-tear film interaction.

    Science.gov (United States)

    Holly, F J

    1981-04-01

    The successful fitting of contact lenses requires the practitioner to take into account many properties of the specific lens type used but the practitioner must also understand patient factors including tear properties, use of appropriate solutions, procedures for lens cleaning, and efficiency of blinking. Selection of appropriate patients, selection of lens type, proper fitting, good maintenance, and training and monitoring of patients increase the probability of achieving success.

  9. Rapid identification of the quality decoction pieces by partial least squares -based pattern recognition: grade classification of the decoction pieces of Saposhnikovia divaricata.

    Science.gov (United States)

    Liu, Ying; Li, Li; Xiao, Yongqing; Yao, Jiaqi; Li, Pengyuan; Chen, Liang; Yu, Dingrong; Ma, Yinlian

    2016-08-01

    Herbal medicines are commonly used in many countries after they undergo processing. Quality decoction pieces are a guarantee of the efficacy and safety of the herbal medical products. Here, a strategy based on chemical analysis combined with chemometric techniques was proposed for the classification and prediction of the different grades of the decoction pieces. Considering the necessity for a shared and simple method for the grade classification for the public, in this paper, the characterization of the chemical constituents was determined by utilizing high-performance liquid chromatography (HPLC)/diode array detection. HPLC was first established for the characterization of the chemical constituents of the different grade decoction pieces. Furthermore, a simultaneous quantification of several of the marker compounds in these decoction pieces was obtained. Finally, a partial least squares-based pattern recognition method was utilized to obtain a predictive model for the grade classification of the decoction pieces. Saposhnikovia divaricata (Turcz.) Schischk was used as a case study. The partial least squares -based pattern recognition for the grade classification of the decoction pieces of S. divaricata demonstrated good sensitivity, specificity and prediction performance, which may efficiently validate the identification results of appearance assessment. The proposed strategy is expected to provide a new insight for the grade classification and quality control of the decoction pieces. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  10. Placement of a crystalline lens and intraocular lens: Retinal image quality.

    Science.gov (United States)

    Siedlecki, Damian; Nowak, Jerzy; Zajac, Marek

    2006-01-01

    The influence of changes of both crystalline lens and intraocular lens (IOL) misalignment on the retinal image quality was investigated. The optical model of the eye used in investigations was the Liou-Brennan model, which is commonly considered as one of the most anatomically accurate. The original crystalline lens from this model was replaced with an IOL, made of rigid polymethylmethacrylate, in a way that recommend obligatory procedures. The modifications that were made both for crystalline lens and IOL were the longitudinal, the transversal, and the angular displacement.

  11. Restoring lens capsule integrity enhances lens regeneration in New Zealand albino rabbits and cats.

    Science.gov (United States)

    Gwon, A; Gruber, L J; Mantras, C

    1993-11-01

    In studies conducted by numerous investigators for 150 years, lenses regenerated following endocapsular lens extraction in New Zealand albino rabbits have been irregular in shape, appearing primarily doughnut-shaped as a result of lack of lens growth at the site of the anterior capsulotomy and its adhesion to the posterior capsule. In the present study, we restored the lens capsule integrity by inserting a collagen patch at the time of surgery to seal the anterior capsulotomy and to improve the shape and structure of the regenerated lenses. We then filled the capsule bag with air to prevent adhesions between the anterior and posterior capsule and maintain capsule tautness and shape. Lens regeneration was first noted as early as one to two weeks. Regenerated lens filled approximately 50% of the capsule bag at two weeks and 100% by five weeks. Subsequent growth was in the anterior-posterior direction and measured by A-scan biometry. Lens thickness increased by 0.3 mm per month. The regenerated lenses were spherical with normal cortical structure and a nuclear opacity. In conclusion, restoration of lens capsular integrity with a collagen patch following endocapsular lens extraction enhanced the shape, structure, and growth rate of the regenerated lenses. In addition, lens regeneration was shown to occur in two cats.

  12. Development of Fresnel lens for improvement of rear visibility; Shikai kojo Fresnel lens no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Iwamoto, K.; Sanada, C.; Tsukino, M. [Nissan Motor Co. Ltd., Tokyo (Japan)

    1997-10-01

    Fresnel lenses have been widely used to increase the visual field around vehicles for drivers. However, internal reflection in these lenses has been an obstacle in producing dear images. This internal glow is generated by incident light from an unexpected direction reflecting on the non-lens surface or radiating from the non-lens surface of the Fresnel lens. The cause of internal glow has been made dear combining louver film with the lens. The newly developed technology removes obstacles in producing dear images by reducing internal glow. 7 figs.

  13. Night Vision Goggles Objectives Lens Focusing Methodology

    National Research Council Canada - National Science Library

    Pinkus, Alan; Task, H. L

    2000-01-01

    ...: interpupillary distance, tilt, eye relief, height, eyepiece and objective lens focus. Currently, aircrew use a Hoffman 20/20 test unit to pre-focus their NVG objective lenses at optical infinity before boarding their aircraft...

  14. Role of Aquaporin 0 in lens biomechanics

    Energy Technology Data Exchange (ETDEWEB)

    Sindhu Kumari, S.; Gupta, Neha [Physiology and Biophysics, Stony Brook University, Stony Brook, NY (United States); Shiels, Alan [Washington University School of Medicine, St. Louis, MO (United States); FitzGerald, Paul G. [Cell Biology and Human Anatomy, School of Medicine, University of California, Davis, CA (United States); Menon, Anil G. [University of Cincinnati College of Medicine, Cincinnati, OH (United States); Mathias, Richard T. [Physiology and Biophysics, Stony Brook University, Stony Brook, NY (United States); SUNY Eye Institute, NY (United States); Varadaraj, Kulandaiappan, E-mail: kulandaiappan.varadaraj@stonybrook.edu [Physiology and Biophysics, Stony Brook University, Stony Brook, NY (United States); SUNY Eye Institute, NY (United States)

    2015-07-10

    Maintenance of proper biomechanics of the eye lens is important for its structural integrity and for the process of accommodation to focus near and far objects. Several studies have shown that specialized cytoskeletal systems such as the beaded filament (BF) and spectrin-actin networks contribute to mammalian lens biomechanics; mutations or deletion in these proteins alters lens biomechanics. Aquaporin 0 (AQP0), which constitutes ∼45% of the total membrane proteins of lens fiber cells, has been shown to function as a water channel and a structural cell-to-cell adhesion (CTCA) protein. Our recent ex vivo study on AQP0 knockout (AQP0 KO) mouse lenses showed the CTCA function of AQP0 could be crucial for establishing the refractive index gradient. However, biomechanical studies on the role of AQP0 are lacking. The present investigation used wild type (WT), AQP5 KO (AQP5{sup −/−}), AQP0 KO (heterozygous KO: AQP0{sup +/−}; homozygous KO: AQP0{sup −/−}; all in C57BL/6J) and WT-FVB/N mouse lenses to learn more about the role of fiber cell AQPs in lens biomechanics. Electron microscopic images exhibited decreases in lens fiber cell compaction and increases in extracellular space due to deletion of even one allele of AQP0. Biomechanical assay revealed that loss of one or both alleles of AQP0 caused a significant reduction in the compressive load-bearing capacity of the lenses compared to WT lenses. Conversely, loss of AQP5 did not alter the lens load-bearing ability. Compressive load-bearing at the suture area of AQP0{sup +/−} lenses showed easy separation while WT lens suture remained intact. These data from KO mouse lenses in conjunction with previous studies on lens-specific BF proteins (CP49 and filensin) suggest that AQP0 and BF proteins could act co-operatively in establishing normal lens biomechanics. We hypothesize that AQP0, with its prolific expression at the fiber cell membrane, could provide anchorage for cytoskeletal structures like BFs and

  15. Retrospective multicenter analysis of immediate provisionalization using one-piece narrow-diameter (3.0-mm) implants.

    Science.gov (United States)

    Sohn, Dong-Seok; Bae, Min-Su; Heo, Jeong-Uk; Park, Jun-Sub; Yea, Sun-Hae; Romanos, Georgios E

    2011-01-01

    The aim of this retrospective analysis was to report on the clinical outcome of immediate provisionalization using one-piece narrow-diameter implants. The dental records of patients who received narrow implants were reviewed. Narrow-diameter (3.0-mm) one-piece implants were used to support restorations of missing maxillary lateral incisors and mandibular incisors. All implants were placed in a one-stage procedure according to the protocol recommended by the manufacturer, with immediate placement of provisional restorations. Following an average healing period of 3 months in the mandible and 5 months in the maxilla, the definitive prostheses were fabricated. The survival rate of the implants was analyzed, and radiographic evaluation was performed. RESULTS. Thirty-six patients (20 men and 16 women), aged from 42 to 72 years (average age of 53 years), were treated with 62 one-piece narrow implants. A success rate of 100% was observed over a period up to 33 months (mean, 23 ± 4.3 months). Among these, 8 implants were placed in maxillary lateral incisor positions and 54 implants were placed in mandibular incisor areas. Forty-four implants supported fixed partial prostheses, and 18 implants supported single crowns. The majority of the implants were 15 mm in length. Mean marginal bone loss at the 12-month follow-up visit was 0.53 ± 0.37 mm (range, 0 to 1.4 mm). The results obtained in this retrospective analysis suggest that the one-piece narrow-diameter implant can predictably restore missing maxillary lateral incisors and mandibular incisor with narrow interdental spaces and labiolingual widths.

  16. Contractual considerations in contact lens practice.

    Science.gov (United States)

    Classé, J G

    1986-03-01

    The use of forms in contact lens practice can save time, promote patient education, and reduce the opportunity for legal or economic disputes. The most commonly employed forms are those for contact lens fitting agreements, instructions for care and maintenance of lenses, prepaid service agreements, clinical investigations of investigatory lenses or solutions, and for extended wear patients. Sample forms are utilized for purposes of illustration.

  17. Evolution and the Calcite Eye Lens

    OpenAIRE

    Williams, Vernon L.

    2013-01-01

    Calcite is a uniaxial, birefringent crystal, which in its optically transparent form, has been used for animal eye lenses, the trilobite being one such animal. Because of the calcite birefringence there is a difficulty in using calcite as a lens. When the propagation direction of incoming light is not exactly on the c-axis, the mages blur. In this paper, calcite blurring is evaluated, and the non-blurring by a crystallin eye lens is compared to a calcite one.

  18. Acute lens-induced glaucomas: A review

    Directory of Open Access Journals (Sweden)

    Syed Shoeb Ahmad

    2017-02-01

    Full Text Available Lens-induced factors are important and common mechanisms causing acute elevation of intraocular pressure. While in most cases, the diagnosis and management are straight-forward, in others it is difficult and can lead to improper procedures, complications and poor visual outcomes. This review was done with the aim of studying the various types of lens-induced glaucomas, classifying them in an easy way to understand manner, their clinical features, current management and future possibilities.

  19. Randomized Trial of the Effect of Contact Lens Wear on Self-Perception in Children

    NARCIS (Netherlands)

    Walline, J.J.; Jones, L.A.; Sinnott, L.; Chitkara, M.; Coffey, B.; Jackson, J.M.; Manny, R.E.; Rath, M.J.; Prinstein, M.J.

    2009-01-01

    Purpose. To determine whether contact lens wear affects children's self-perceptions. Methods. The Adolescent and Child Health Initiative to Encourage Vision Empowerment Study was a randomized, single-masked trial conducted at five clinical centers in the United States. Subjects were 8- to

  20. [Preliminary study on standardization of production and processing of Angelicae Sinensis Radix pieces].

    Science.gov (United States)

    Nie, Rui-Jie; Wang, Ying-Zi; Sun, Zhen-Yang; Wang, Si-Yu; Zhang, Jing-Zhen

    2017-12-01

    Study on the standardization of Chinese materia medica is an important action for modernization and globalization for traditional Chinese medicine. Standardization on the processing of Chinese herbal pieces is an important part in the study on standardization of Chinese materia medica, so it is of great significance to establish the technical processing standards of Angelicae Sinensis Radix pieces for improving its quality. In this study, single factor experiment was designed to optimize the softening, cutting and drying processes of Angelicae Sinensis Radix. With ferulic acid, Angelicae Sinensis Radix polysaccharide, volatile oil and extracts (water and ethanol) content as the quality index, the effects of different softening, cutting and drying processes on the contents of the five components in Angelicae Sinensis Radix were analyzed, and the normalized distance evaluation method was used to analyze the experimental data. The results showed that the content of five components in Angelicae Sinensis Radix was affected by different softening methods and drying temperature, but the thickness of slice had little effect on the content. The best preparation process for Angelicae Sinensis Radix was as follows: Non-medicinal parts were removed; mildewed and rot as well as moth-eaten parts were removed; washed by the flowing drinking water; stacked in the drug pool; moistening method was used for softening, where 125 mL water was sprayed for every 1 kg of herbs every 2.5 h; upper part of herbs covered with clean and moist cotton, and cut into thin slices (1-2 mm) after 15 h moistening until appropriate softness, with disk thickness of 1-2 cm, then received blast drying for 6 h at 55 ℃, and turned over for 2 times during the drying. Copyright© by the Chinese Pharmaceutical Association.

  1. Unintentional variation in positive end expiratory pressure during resuscitation with a T-piece resuscitator.

    Science.gov (United States)

    Finer, Neil N; Rich, Wade D

    2011-06-01

    The ability of T-piece resuscitators to deliver consistent peak inspiratory pressure (PIP) and positive end expiratory pressure (PEEP) during real and simulated neonatal resuscitation has been well described. The Neopuff (Fisher & Paykel Healthcare, Auckland, New Zealand) has been the device used for nearly all of these comparisons. All high risk resuscitations were carried out in our dedicated resuscitation room, and were recorded on video tape for quality assurance purposes.(1) In addition to the audio and video recording, physiologic signals and resuscitation parameters, including oxygen saturation, pulse rate, airway pressure, FiO(2), and others signals as appropriate were also captured. These recordings were reviewed on a biweekly basis as part of a continuing quality review process. Resuscitations were graded for standard of care and the resuscitation checklist was reviewed to determine if the team had any unresolved issues that needed to be addressed. In the year between April of 2009 and March 2010, a period when we fully reviewed approximately 120 videos, we recognized visually obvious PEEP changes on 8 different occasions in ELBW infants. Our target PEEP was 5 cm H20. We observed rapid changes in the PEEP to as high as 15 cm H20 during resuscitation. Based on our single-center experience, a T-piece resuscitation device which has the adjustment for the PEEP level and the orifice which is occluded to deliver a breath in the same location has the potential to cause an inadvertent and potentially toxic increase of PEEP which might not be noticed by the operator. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  2. Immediate occlusal loading of one-piece zirconia implants: five-year radiographic and clinical evaluation.

    Science.gov (United States)

    Grassi, Felice Roberto; Capogreco, Mario; Consonni, Dario; Bilardi, Germano; Buti, Jacopo; Kalemaj, Zamira

    2015-01-01

    To evaluate radiographic and clinical outcomes of immediate occlusally loaded one-piece zirconia implants after 5 years of follow-up. This longitudinal clinical investigation included patients older than 18 years, in need of implant-supported single-unit dental rehabilitations. One-piece zirconia in healed and postextraction sites and immediately restored with provisional crowns in light occlusal contact. Definitive zirconia-ceramic restorations were delivered 3 to 4 months after surgery. Primary estimated outcomes were implant survival and success. Periapical radiographs were taken at implant insertion (T0), after 1 year (T1), and after 5 years (T2) to assess marginal bone loss (MBL). Probing depth (PD), modified Bleeding Index (mBI), modified Plaque Index (mPI), and gingival recession (REC) were also measured repeatedly for implants and reference teeth. Changes in parameters over time were assessed using the Wilcoxon signed rank test. In addition, multilevel mixed effects linear and logistic regression models were fitted to take into account within-subject correlations and baseline values. Thirty-two implants were inserted in postextraction and healed sites (n = 16 of each) in 17 patients. One immediate implant was lost after 3 months, and one patient with one implant dropped out after T1. Therefore, the cumulative survival rates were 96.9% at T1 and 96.8% at T2 (4.3 to 6 years). No significant differences were observed in mean MBL between immediate and delayed implants at either T1 or T2. Moreover, different baseline parameters (sex, arch, implant location, smoking habits, grafting) did not show any influence on MBL at either time. In general, for all clinical parameters (PD, mBI, mPI, REC), implants seemed to perform similar to if not better than natural teeth. Radiographic and clinical evaluations after 5 years showed satisfactory amounts of MBL and acceptable soft tissue health.

  3. Acoustic lens for capacitive micromachined ultrasonic transducers

    Science.gov (United States)

    Chang, Chienliu; Firouzi, Kamyar; Park, Kwan Kyu; Sarioglu, Ali Fatih; Nikoozadeh, Amin; Yoon, Hyo-Seon; Vaithilingam, Srikant; Carver, Thomas; Khuri-Yakub, Butrus T.

    2014-08-01

    Capacitive micromachined ultrasonic transducers (CMUTs) have great potential to compete with traditional piezoelectric transducers in therapeutic ultrasound applications. In this paper we have designed, fabricated and developed an acoustic lens formed on the CMUT to mechanically focus ultrasound. The acoustic lens was designed based on the paraxial theory and made of silicone rubber for acoustic impedance matching and encapsulation. The CMUT was fabricated based on the local oxidation of silicon (LOCOS) and fusion-bonding. The fabricated CMUT was verified to behave like an electromechanical resonator in air and exhibited wideband response with a center frequency of 2.2 MHz in immersion. The fabrication for the acoustic lens contained two consecutive mold castings and directly formed on the surface of the CMUT. Applied with ac burst input voltages at the center frequency, the CMUT with the acoustic lens generated an output pressure of 1.89 MPa (peak-to-peak) at the focal point with an effective focal gain of 3.43 in immersion. Compared to the same CMUT without a lens, the CMUT with the acoustic lens demonstrated the ability to successfully focus ultrasound and provided a viable solution to the miniaturization of the multi-modality forward-looking endoscopes without electrical focusing.

  4. Acoustic lens for capacitive micromachined ultrasonic transducers

    International Nuclear Information System (INIS)

    Chang, Chienliu; Firouzi, Kamyar; Sarioglu, Ali Fatih; Nikoozadeh, Amin; Yoon, Hyo-Seon; Vaithilingam, Srikant; Carver, Thomas; Khuri-Yakub, Butrus T; Kyu Park, Kwan

    2014-01-01

    Capacitive micromachined ultrasonic transducers (CMUTs) have great potential to compete with traditional piezoelectric transducers in therapeutic ultrasound applications. In this paper we have designed, fabricated and developed an acoustic lens formed on the CMUT to mechanically focus ultrasound. The acoustic lens was designed based on the paraxial theory and made of silicone rubber for acoustic impedance matching and encapsulation. The CMUT was fabricated based on the local oxidation of silicon (LOCOS) and fusion-bonding. The fabricated CMUT was verified to behave like an electromechanical resonator in air and exhibited wideband response with a center frequency of 2.2 MHz in immersion. The fabrication for the acoustic lens contained two consecutive mold castings and directly formed on the surface of the CMUT. Applied with ac burst input voltages at the center frequency, the CMUT with the acoustic lens generated an output pressure of 1.89 MPa (peak-to-peak) at the focal point with an effective focal gain of 3.43 in immersion. Compared to the same CMUT without a lens, the CMUT with the acoustic lens demonstrated the ability to successfully focus ultrasound and provided a viable solution to the miniaturization of the multi-modality forward-looking endoscopes without electrical focusing. (paper)

  5. LENS: Science Scope and Development Stages

    Science.gov (United States)

    Vogelaar, R. Bruce

    2013-04-01

    The Low-Energy Neutrino Spectroscopy (LENS) experiment will resolve the solar metallicity question via measurement of the CNO neutrino flux, as well as test the predicted equivalence of solar luminosity as measured by photon versus neutrinos. The LENS detector uses charged-current interaction of neutrinos on Indium-115 (loaded in a scintillator, InLS) to reveal the complete solar neutrino spectrum. LENS's optically segmented 3D lattice geometry achieves precise time and spatial resolution and unprecedented background rejection and sensitivity for low-energy neutrino events. This first-of-a-kind lattice design is also suited for a range of other applications where high segmentation and large light collection are required (eg: sterile neutrinos with sources, double beta decay, and surface detection of reactor neutrinos). The physics scope, detector design, and logic driving the microLENS and miniLENS prototyping stages will be presented. The collaboration is actively running programs; building, operating, developing, and simulating these prototypes using the Kimballton Underground Research Facility (KURF). New members are welcome to the LENS Collaboration, and interested parties should contact R. Bruce Vogelaar.

  6. Exploitation and application of radio-scanning cigarette cartoon lacking pieces online detection system

    International Nuclear Information System (INIS)

    Yang Qicheng; Ma Yunshen; Luo Bing; Chen Yong; Chen Yongfu

    2008-01-01

    Taking Hongta's detecting cigarette cartoon lacking pieces and eliminating it in the course of end-product automatic sorting consignment as an example, this paper introduces detailedly one type of cigarette cartoon lacking pieces online detection system with advantages of original principle, accurate detection, high speed and reliable performance, from the aspects of project design, detection principle, hard-ware configuration, applied technique, running status and etc. Gives one method of detecting and controlling cigarette product lacking pieces for cigarette manufactures. (authors)

  7. Individuality in harpsichord performance: disentangling performer- and piece-specific influences on interpretive choices.

    Science.gov (United States)

    Gingras, Bruno; Asselin, Pierre-Yves; McAdams, Stephen

    2013-01-01

    Although a growing body of research has examined issues related to individuality in music performance, few studies have attempted to quantify markers of individuality that transcend pieces and musical styles. This study aims to identify such meta-markers by discriminating between influences linked to specific pieces or interpretive goals and performer-specific playing styles, using two complementary statistical approaches: linear mixed models (LMMs) to estimate fixed (piece and interpretation) and random (performer) effects, and similarity analyses to compare expressive profiles on a note-by-note basis across pieces and expressive parameters. Twelve professional harpsichordists recorded three pieces representative of the Baroque harpsichord repertoire, including three interpretations of one of these pieces, each emphasizing a different melodic line, on an instrument equipped with a MIDI console. Four expressive parameters were analyzed: articulation, note onset asynchrony, timing, and velocity. LMMs showed that piece-specific influences were much larger for articulation than for other parameters, for which performer-specific effects were predominant, and that piece-specific influences were generally larger than effects associated with interpretive goals. Some performers consistently deviated from the mean values for articulation and velocity across pieces and interpretations, suggesting that global measures of expressivity may in some cases constitute valid markers of artistic individuality. Similarity analyses detected significant associations among the magnitudes of the correlations between the expressive profiles of different performers. These associations were found both when comparing across parameters and within the same piece or interpretation, or on the same parameter and across pieces or interpretations. These findings suggest the existence of expressive meta-strategies that can manifest themselves across pieces, interpretive goals, or expressive devices.

  8. Individuality in harpsichord performance: Disentangling performer- and piece-specific influences on interpretive choices

    Directory of Open Access Journals (Sweden)

    Bruno eGingras

    2013-11-01

    Full Text Available Although a growing body of research has examined issues related to individuality in music performance, few studies have attempted to quantify markers of individuality that transcend pieces and musical styles. This study aims to identify such meta-markers by discriminating between influences linked to specific pieces or interpretive goals and performer-specific playing styles, using two complementary statistical approaches: linear mixed models (LMMs to estimate fixed (piece and interpretation and random (performer effects, and similarity analyses to compare expressive profiles on a note-by-note basis across pieces and expressive parameters. Twelve professional harpsichordists recorded three pieces representative of the Baroque harpsichord repertoire, including three interpretations of one of these pieces, each emphasizing a different melodic line, on an instrument equipped with a MIDI console. Four expressive parameters were analyzed: articulation, note onset asynchrony, timing, and velocity. LMMs showed that piece-specific influences were much larger for articulation than for other parameters, for which performer-specific effects were predominant, and that piece-specific influences were generally larger than effects associated with interpretive goals. Some performers consistently deviated from the mean values for articulation and velocity across pieces and interpretations, suggesting that global measures of expressivity may in some cases constitute valid markers of artistic individuality. Similarity analyses detected significant associations among the magnitudes of the correlations between the expressive profiles of different performers. These associations were found both when comparing across parameters and within the same piece or interpretation, or on the same parameter and across pieces or interpretations. These findings suggest the existence of expressive meta-strategies that can manifest themselves across pieces, interpretive goals, or

  9. The Illocutionary Acts of Luffy's Utterances to His Addressees in Comic One Piece

    OpenAIRE

    Fasril, Adhy Kurnia Putra; Bachtiar, Bachtiar

    2012-01-01

    One aim of this article is to show through a concrete example how illocutionary acts used in One Piece comic. The illustrative example is taken from the utterances of One Piece comic. Central to the analysis proper form of utterances in One Piece comic that contain of illocutionary acts; i.e. representative, directive, commissive, expressive, declarative. 90 utterances were interpreted by actor, and it was found that the use of iilocutionary acts.

  10. Deep convolutional neural networks as strong gravitational lens detectors

    Science.gov (United States)

    Schaefer, C.; Geiger, M.; Kuntzer, T.; Kneib, J.-P.

    2018-03-01

    Context. Future large-scale surveys with high-resolution imaging will provide us with approximately 105 new strong galaxy-scale lenses. These strong-lensing systems will be contained in large data amounts, however, which are beyond the capacity of human experts to visually classify in an unbiased way. Aim. We present a new strong gravitational lens finder based on convolutional neural networks (CNNs). The method was applied to the strong-lensing challenge organized by the Bologna Lens Factory. It achieved first and third place, respectively, on the space-based data set and the ground-based data set. The goal was to find a fully automated lens finder for ground-based and space-based surveys that minimizes human inspection. Methods: We compared the results of our CNN architecture and three new variations ("invariant" "views" and "residual") on the simulated data of the challenge. Each method was trained separately five times on 17 000 simulated images, cross-validated using 3000 images, and then applied to a test set with 100 000 images. We used two different metrics for evaluation, the area under the receiver operating characteristic curve (AUC) score, and the recall with no false positive (Recall0FP). Results: For ground-based data, our best method achieved an AUC score of 0.977 and a Recall0FP of 0.50. For space-based data, our best method achieved an AUC score of 0.940 and a Recall0FP of 0.32. Adding dihedral invariance to the CNN architecture diminished the overall score on space-based data, but achieved a higher no-contamination recall. We found that using committees of five CNNs produced the best recall at zero contamination and consistently scored better AUC than a single CNN. Conclusions: We found that for every variation of our CNN lensfinder, we achieved AUC scores close to 1 within 6%. A deeper network did not outperform simpler CNN models either. This indicates that more complex networks are not needed to model the simulated lenses. To verify this, more

  11. Preservation of refrigerated calf meat pieces by ionization

    International Nuclear Information System (INIS)

    Hassouna, M.; Besbes, M.; Ben Hassen, A.; Mahjoub, A.; Maalej, M.

    1998-01-01

    The influence of five 60Co gamma radiation doses in the range of 1 to 5 kGy on chemical composition and bacteriological counts of pieces of calf meat, partially vacuum - packed before treatment, was studied during storage at + 4 degree C up to 28 days. In vivo thermoluminescence dosimetry (TLD) using dosimeters such as lithium fluoride (LiF) was used as a very sensitive procedure to control both dose delivered to the red meat and its degree of uniformity. These two parameters are generally recommended for the quality control of food irradiation process. While ionizing radiation doses of 1 or 2 kGy were unable to increase the shelf life of treated meat, doses of 3, 4 or 5 kGy were very efficient, and adequate to prevent completely the growth of microorganisms indicating faecal contamination such as total coliforms, faecal coliforms and Enterobacteriaceae; they also kept constant the contents of total mesophilic flora and maintained radioresistant psychrotrophic microflora below the value inducing superficial putrefaction of meat (10 7 CFU cntdot g -1 ) at all storage times. Pathogenic germs producing contaminating toxins in foodstuffs such as Salmonella, Staphylococcus aureus and anaerobic sulfite reducing bacteria were totally absent in both control and treated meat. When pieces of meat were irradiated with doses of 3, 4 or 5 kGy, microbial alcalinization and proteolysis revealed by total volatile basic nitrogen were very low during the whole storage period. In addition, total protein did not change as a result of treatment during that period. However, superficial browning and significant variations were observed in water - holding capacity and saturated and unsaturated fatty acids contents in the free fat of treated meat. Ionizing radiation doses had no effect on weight losses and even on the variations of pH after heating of ground calf meat in double boiler at 50, 70 or 90 degree C up to 1 h. However, these modifications very sensitive to cooking temperature

  12. Combined surgical management of capsular and iris deficiency with glued intraocular lens technique.

    Science.gov (United States)

    Kumar, Dhivya Ashok; Agarwal, Amar; Jacob, Soosan; Lamba, Mandeep; Packialakshmi, Sathiya; Meduri, Alessandro

    2013-05-01

    To determine the outcome after glued aniridia intraocular lens (IOL) and glued IOL with iridoplasty in eyes with combined lens capsular and iris deficiency. Twenty-seven eyes of 25 patients (6 had congenital aniridia with subluxated cataract and 19 had acquired lens/iris defects) were included. Glued IOL with aniridia IOL (Intra Ocular Care, Gujarat, India) was performed in eyes with total aniridia and iridoplasty with glued IOL with a three-piece foldable IOL (Sofport; Bausch & Lomb, Rochester, NY) was performed in eyes with partial aniridia. The postoperative outcomes were analyzed at follow-up examination (range: 6 to 48 months). Eleven eyes underwent glued aniridia IOL and 16 eyes underwent glued IOL with iridoplasty. There was significant improvement in (spectacle) corrected distance visual acuity (CDVA) (P = .002). Postoperatively, pigment dispersion on the IOL (n = 1) and raised intraocular pressure was seen in the glued aniridia IOL group and chronic uveitis (n = 1), cystoid macular edema (n = 1), and hyphema (n = 1) in the glued IOL with iridoplasty group. The CDVA remained unchanged in 14 eyes (51.8%) and improved in 13 eyes (48.1%). There was a difference in postoperative CDVA (P = .001) between eyes with glued aniridia IOL and glued IOL with iridoplasty. There was no IOL decentration, retinal detachment, corneal decompensation, or endophthalmitis. There was reduction in glare and photophobia. Both glued aniridia IOL and glued IOL/iridoplasty showed good functional and anatomical results with fewer complications in eyes with lens capsule and iris deficiency. However, long-term follow-up is required.[J Refract Surg. 2013;29(5):342-347.]. Copyright 2013, SLACK Incorporated.

  13. [Development and innovation of traditional Chinese medicine processing discipline and Chinese herbal pieces industry].

    Science.gov (United States)

    Xiao, Yong-Qing; Li, Li; Liu, Ying; Ma, Yin-Lian; Yu, Ding-Rong

    2016-01-01

    To elucidate the key issues in the development and innovation of traditional Chinese medicine processing discipline and Chinese herbal pieces industry Chinese herbal pieces industry. According to the author's accumulated experience over years and demand of the development of the Chinese herbal pieces industry, the key issues in the development and innovation on the Chinese herbal pieces industry were summarized. According to the author, the traditional Chinese medicine processing discipline shall focus on a application basis research. The development of this discipline should be closely related to the development of Chinese herbal pieces. The traditional Chinese medicine processing discipline can be improved and its results can be transformed only if this discipline were correlated with the Chinese herbal pieces industry, matched with the development of the Chinese herbal pieces industry, and solved the problems in the development on the Chinese herbal pieces industry. The development of traditional Chinese medicine processing discipline and the Chinese herbal pieces industry also requires scientific researchers to make constant innovations, realize the specialty of the researches, and innovate based on inheritance. Copyright© by the Chinese Pharmaceutical Association.

  14. Sharing of secondary electrons by in-lens and out-lens detector in low-voltage scanning electron microscope equipped with immersion lens.

    Science.gov (United States)

    Kumagai, Kazuhiro; Sekiguchi, Takashi

    2009-03-01

    To understand secondary electron (SE) image formation with in-lens and out-lens detector in low-voltage scanning electron microscopy (LV-SEM), we have evaluated SE signals of an in-lens and an out-lens detector in LV-SEM. From the energy distribution spectra of SEs with various boosting voltages of the immersion lens system, we revealed that the electrostatic field of the immersion lens mainly collects electrons with energy lower than 40eV, acting as a low-pass filter. This effect is also observed as a contrast change in LV-SEM images taken by in-lens and out-lens detectors.

  15. Bone response from a dynamic stimulus on a one-piece and multi-piece implant abutment and crown by finite element analysis.

    Science.gov (United States)

    Hajimiragha, Habib; Abolbashari, Mohammadreza; Nokar, Saeed; Abolbashari, AmirHossein; Abolbashari, Mehrdad

    2014-10-01

    The present study was done to evaluate the effects of different types of abutments on the rate and distribution of stress on the bone surrounding the implant by dynamic finite element analysis method. In this study two ITI abutment models-one-piece and multi-piece-along with fixture, bone, and superstructure have been simulated with the help of company-made models. The maximum Von Mises stress (MVMS) was observed in the distobuccal area of the cortical bone near the crest of implant in two implant models. In the multi-piece abutment, MVMS was higher than the one-piece model (27.9 MPa and 23.3 MPa, respectively). Based on the results of this study, it can be concluded that type of abutment influences the stress distribution in the area surrounding the implant during dynamic loading.

  16. Hydrometallurgical Recovery of Metals from Large Printed Circuit Board Pieces

    Science.gov (United States)

    Jadhav, U.; Hocheng, H.

    2015-09-01

    The recovery of precious metals from waste printed circuit boards (PCBs) is an effective recycling process. This paper presents a promising hydrometallurgical process to recover precious metals from waste PCBs. To simplify the metal leaching process, large pieces of PCBs were used instead of a pulverized sample. The chemical coating present on the PCBs was removed by sodium hydroxide (NaOH) treatment prior to the hydrometallurgical treatment. Among the leaching reagents examined, hydrochloric acid (HCl) showed great potential for the recovery of metals. The HCl-mediated leaching of waste PCBs was investigated over a range of conditions. Increasing the acid concentration decreased the time required for complete metal recovery. The shaking speed showed a pronounced positive effect on metal recovery, but the temperature showed an insignificant effect. The results showed that 1 M HCl recovered all of the metals from 4 cm × 4 cm PCBs at room temperature and 150 rpm shaking speed in 22 h.

  17. A One-Piece Lunar Regolith Bag Garage Prototype

    Science.gov (United States)

    Smithers, G. A.; Nehls, M. K.; Hovater, M. A.; Evans, S. W.; Miller, J. S.; Broughton, R. M., Jr.; Beale, D.; Kilinc-Balci, F.

    2007-01-01

    Shelter structures on the moon, even in early phases of exploration, should incorporate lunar materials as much as possible. This Technical Memorandum details the design and construction of a prototype for a one-piece regolith bag unpressurized garage concept and a materials testing program to investigate six candidate fabrics to learn how they might perform in the lunar environment. The conceptualization was that a lightweight fabric form be launched from Earth and landed on the lunar surface to be robotically filled with raw lunar regolith. Regolith bag fabric candidates included: Vectran(TM), Nextel(TM), Gore PTFE Fabric(TM), Zylon(TM), Twaron(TM), and Nomex(TM). Tensile (including post radiation exposure), fold, abrasion, and hypervelocity impact testing were performed under ambient conditions, and also performed under cold and elevated temperatures. In some cases, Johnson Space Center lunar simulant (JSC-1) was used in conjunction with testing. A series of preliminary structures was constructed during final prototype design based on the principles of the classic masonry arch. The prototype was constructed of Kevlar(TM) and filled with vermiculite. The structure is free-standing, but has not yet been load tested. Future plans would be to construct higher fidelity prototypes and to conduct appropriate tests of the structure.

  18. Tethered capsule OCT endomicroscopy for upper gastrointestinal tract imaging by using ball lens probe (Conference Presentation)

    Science.gov (United States)

    Dong, Jing; Gora, Michalina J.; Reddy, Rohith; Trasischker, Wolfgang; Poupart, Oriane; Lu, Weina; Carruth, Robert W.; Grant, Catriona N.; Soomro, Amna R.; Tiernan, Aubrey R.; Rosenberg, Mireille; Nishioka, Norman S.; Tearney, Guillermo J.

    2016-03-01

    While endoscopy is the most commonly used modality for diagnosing upper GI tract disease, this procedure usually requires patient sedation that increases cost and mandates its operation in specialized settings. In addition, endoscopy only visualizes tissue superfically at the macroscopic scale, which is problematic for many diseases that manifest below the surface at a microscopic scale. Our lab has previously developed technology termed tethered capsule OCT endomicroscopy (TCE) to overcome these diagnostic limitations of endoscopy. The TCE device is a swallowable capsule that contains optomechanical components that circumferentially scan the OCT beam inside the body as the pill traverses the organ via peristalsis. While we have successfully imaged ~100 patients with the TCE device, the optics of our current device have many elements and are complex, comprising a glass ferrule, optical fiber, glass spacer, GRIN lens and prism. As we scale up manufacturing of this device for clinical translation, we must decrease the cost and improve the manufacturability of the capsule's optical configuration. In this abstract, we report on the design and development of simplificed TCE optics that replace the GRIN lens-based configuration with an angle-polished ball lens design. The new optics include a single mode optical fiber, a glass spacer and an angle polished ball lens, that are all fusion spliced together. The ball lens capsule has resolutions that are comparable with those of our previous GRIN lens configuration (30µm (lateral) × 7 µm (axial)). Results in human subjects show that OCT-based TCE using the ball lens not only provides rapid, high quality microstructural images of upper GI tract, but also makes it possible to implement this technology inexpensively and on a larger scale.

  19. Acanthamoeba keratitis and contact lens wear.

    Science.gov (United States)

    Lindsay, Richard G; Watters, Grant; Johnson, Richard; Ormonde, Susan E; Snibson, Grant R

    2007-09-01

    Acanthamoeba keratitis is a rare but serious complication of contact lens wear that may cause severe visual loss. The clinical picture is usually characterised by severe pain, sometimes disproportionate to the signs, with an early superficial keratitis that is often misdiagnosed as herpes simplex virus (HSV) keratitis. Advanced stages of the infection are usually characterised by central corneal epithelial loss and marked stromal opacification with subsequent loss of vision. In this paper, six cases of contact lens-related Acanthamoeba keratitis that occurred in Australia and New Zealand over a three-year period are described. Three of the patients were disposable soft lens wearers, two were hybrid lens wearers and one was a rigid gas permeable lens wearer. For all six cases, the risk factors for Acanthamoeba keratitis were contact lens wear with inappropriate or ineffective lens maintenance and exposure of the contact lenses to tap or other sources of water. All six patients responded well to medical therapy that involved topical use of appropriate therapeutic agents, most commonly polyhexamethylene biguanide and propamidine isethionate, although two of the patients also subsequently underwent deep lamellar keratoplasty due to residual corneal surface irregularity and stromal scarring. Despite the significant advances that have been made in the medical therapy of Acanthamoeba keratitis over the past 10 years, prevention remains the best treatment and patients who wear contact lenses must be thoroughly educated about the proper use and care of the lenses. In particular, exposure of the contact lenses to tap water or other sources of water should be avoided.

  20. Properties of the cathode lens combined with a focusing magnetic/immersion-magnetic lens

    International Nuclear Information System (INIS)

    Konvalina, I.; Muellerova, I.

    2011-01-01

    The cathode lens is an electron optical element in an emission electron microscope accelerating electrons from the sample, which serves as a source for a beam of electrons. Special application consists in using the cathode lens first for retardation of an illuminating electron beam and then for acceleration of reflected as well as secondary electrons, made in the directly imaging low energy electron microscope or in its scanning version discussed here. In order to form a real image, the cathode lens has to be combined with a focusing magnetic lens or a focusing immersion-magnetic lens, as used for objective lenses of some commercial scanning electron microscopes. These two alternatives are compared with regards to their optical properties, in particular with respect to predicted aberration coefficients and the spot size, as well as the optimum angular aperture of the primary beam. The important role of the final aperture size on the image resolution is also presented.

  1. Experimental observation of lens damage after low doses of γ-ray irradiation to rabbit eyes

    International Nuclear Information System (INIS)

    Tang Xicheng; Hu Chunzhi; Wang Huijun; Zeng Aiping

    2000-01-01

    Objective: To investigate and evaluate low dose γ-ray radiation induced lens damage. Methods: Both eyes of each rabbit were exposed to a single dose of 25 or 50 cGy γ-rays in two groups, respectively. Samples were examined by transmission electron microscopy (TEM) and slit lamp microscopy (SLM)after irradiation. Results: Three days after 25 and 50 cGy irradiation,the epithelial cells of lens equator al region showed marked swelling and many vacuoles formed in intercellular space and cytoplasm,and accompanied by increased multi-lamellar bodies. Five months after irradiation, SLM of both groups showed that the posterior sub-capsule cortex exhibited clusters of vacuoles; 11 months after 50 cGy irradiation,the posterior sub-capsule and deep cortex manifested marked cloudy opacities. Conclusion: Low doses of γ-ray (25 and 50 cGy) irradiation can markedly damage lens of rabbits

  2. Gradient-index optical fiber lens for efficient fiber-to-chip coupling.

    Science.gov (United States)

    Melkonyan, Henrik; Al Qubaisi, Kenaish; Sloyan, Karen; Khilo, Anatol; Dahlem, Marcus S

    2017-06-12

    A gradient-index optical fiber lens is proposed and fabricated on the tip of a single-mode fiber using focused ion beam milling. Second-order effective medium theory is used to design a gradual change in the fill factor, which ensures a parabolic effective refractive index distribution. The proposed fiber lens design is simulated via the three-dimensional finite-difference time-domain method, and demonstrated through confocal optical measurements. At a wavelength of 1550 nm, the fabricated lenses focus a 10.4 μm mode field diameter exiting the fiber into spot sizes between 3-5 μm, located 4-6 μm away from the fiber tip. Direct coupling into a silicon-on-insulator chip is also demonstrated, where the fabricated gradient-index lens has a coupling efficiency comparable to a commercial lensed fiber.

  3. Optimization of Process Parameters During End Milling and Prediction of Work Piece Temperature Rise

    Directory of Open Access Journals (Sweden)

    Bhirud N.L.

    2017-09-01

    Full Text Available During the machining processes, heat gets generated as a result of plastic deformation of metal and friction along the tool–chip and tool–work piece interface. In materials having high thermal conductivity, like aluminium alloys, large amount of this heat is absorbed by the work piece. This results in the rise in the temperature of the work piece, which may lead to dimensional inaccuracies, surface damage and deformation. So, it is needed to control rise in the temperature of the work piece. This paper focuses on the measurement, analysis and prediction of work piece temperature rise during the dry end milling operation of Al 6063. The control factors used for experimentation were number of flutes, spindle speed, depth of cut and feed rate. The Taguchi method was employed for the planning of experimentation and L18 orthogonal array was selected. The temperature rise of the work piece was measured with the help of K-type thermocouple embedded in the work piece. Signal to noise (S/N ratio analysis was carried out using the lower-the-better quality characteristics. Depth of cut was identified as the most significant factor affecting the work piece temperature rise, followed by spindle speed. Analysis of variance (ANOVA was employed to find out the significant parameters affecting the work piece temperature rise. ANOVA results were found to be in line with the S/N ratio analysis. Regression analysis was used for developing empirical equation of temperature rise. The temperature rise of the work piece was calculated using the regression equation and was found to be in good agreement with the measured values. Finally, confirmation tests were carried out to verify the results obtained. From the confirmation test it was found that the Taguchi method is an effective method to determine optimised parameters for minimization of work piece temperature.

  4. Material Structure of a Graded Refractive Index Lens in Decapod Squid

    Science.gov (United States)

    Cai, Jing; Heiney, Paul; Sweeney, Alison

    2013-03-01

    Underwater vision with a camera-type eye that is simultaneously acute and sensitive requires a spherical lens with a graded distribution of refractive index. Squids have this type of lens, and our previous work has shown that its optical properties are likely achieved with radially variable densities of a single protein with multiple isoforms. Here we measure the spatial organization of this novel protein material in concentric layers of the lens and use these data to suggest possible mechanisms of self-assembly of the proteins into a graded refractive index structure. First, we performed small angle x-ray scattering (SAXS) to study how the protein is spatially organized. Then, molecular dynamic simulation allowed us to correlate structure to the possible dynamics of the system in different regions of the lens. The combination of simulation and SAXS data in this system revealed the likely protein-protein interactions, resulting material structure and its relationship to the observed and variable optical properties of this graded index system. We believe insights into the material properties of the squid lens system will inform the invention of self-assembling graded index devices.

  5. Lens exposure during brain scans using multidetector row CT scanners: methods for estimation of lens dose.

    Science.gov (United States)

    Suzuki, S; Furui, S; Ishitake, T; Abe, T; Machida, H; Takei, R; Ibukuro, K; Watanabe, A; Kidouchi, T; Nakano, Y

    2010-05-01

    Some recent studies on radiation lens injuries have indicated much lower dose thresholds than specified by the current radiation protection guidelines. The purpose of this research was to measure the lens dose during brain CT scans with multidetector row CT and to assess methods for estimating the lens dose. With 8 types of multidetector row CT scanners, both axial and helical scans were obtained for the head part of a human-shaped phantom by using normal clinical settings with the orbitomeatal line as the baseline. We measured the doses on both eyelids by using an RPLGD during whole-brain scans including the orbit with the starting point at the level of the inferior orbital rim. To assess the effect of the starting points on the lens doses, we measured the lens doses by using 2 other starting points for scanning (the orbitomeatal line and the superior orbital rim). The CTDIvols and the lens doses during whole-brain CT including the orbit were 50.9-113.3 mGy and 42.6-103.5 mGy, respectively. The ratios of lens dose to CTDIvol were 80.6%-103.4%. The lens doses decreased as the starting points were set more superiorly. The lens doses during scans from the superior orbital rim were 11.8%-20.9% of the doses during the scans from the inferior orbital rim. CTDIvol can be used to estimate the lens dose during whole-brain CT when the orbit is included in the scanning range.

  6. Exploiting the dispersion of the double-negative-index fishnet metamaterial to create a broadband low-profile metallic lens.

    Science.gov (United States)

    Orazbayev, B; Pacheco-Peña, V; Beruete, M; Navarro-Cía, M

    2015-04-06

    Metamaterial lenses with close values of permittivity and permeability usually display low reflection losses at the expense of narrow single frequency operation. Here, a broadband low-profile lens is designed by exploiting the dispersion of a fishnet metamaterial together with the zoning technique. The lens operates in a broadband regime from 54 GHz to 58 GHz, representing a fractional bandwidth ~7%, and outperforms Silicon lenses between 54 and 55.5 GHz. This broadband operation is demonstrated by a systematic analysis comprising Huygens-Fresnel analytical method, full-wave numerical simulations and experimental measurements at millimeter waves. For demonstrative purposes, a detailed study of the lens operation at two frequencies is done for the most important lens parameters (focal length, depth of focus, resolution, radiation diagram). Experimental results demonstrate diffraction-limited ~0.5λ transverse resolution, in agreement with analytical and numerical calculations. In a lens antenna configuration, a directivity as high as 16.6 dBi is achieved. The different focal lengths implemented into a single lens could be potentially used for realizing the front end of a non-mechanical zoom millimeter-wave imaging system.

  7. Development of Powerhouse Using Fresnel lens

    Directory of Open Access Journals (Sweden)

    Al-Dohani Nawar Saif

    2018-01-01

    Full Text Available Solar energy is an alternative source of renewable energy. Sultanate of Oman government showed initiation on utilization of solar energy for domestic and industrial applications. Fresnel lens is one of the methods to collect maximum energy by gathering heat of the sun in the concentrated form (using solar collectors. Earlier research work discloses that Fresnel lens gave better result in terms of power output and produces lower heat loss as compared to linear –parabolic solar collectors. In this work, development of a proto Fresnel lens power house was made to generate electricity. The focused heat from Fresnel lens was used to heat the molten salt in a heat exchanger to produce the steam. The generated steam was used to rotate the steam engine coupled to a generator. In the current work, a maximum power of 30 W was produced. In addition, comparative study was carried out regarding solar salts and heat exchanger materials to understand the Fresnel powerhouse performance. Overall the present study gave valuable information regarding usage of Fresnel lens for electricity generation in Oman.

  8. Non-compliance in contact lens wear.

    Science.gov (United States)

    Claydon, B E; Efron, N

    1994-10-01

    Non-compliance is emerging as a critical issue in the contact lens field. This problem has been studied at depth in general health care situations and is seen as the responsibility of both practitioner and patient (client) working in a health care partnership. The contact lens practitioner and patient present a specific case for the study of non-compliance in areas such as hygiene, solution use, appointment attendance and wearing times. From 40 to 91% of contact lens patients have been reported as non-complaint in the use of recommended care and maintenance regimens and many of these are confused or ignorant about their behaviour. In order to arrive at a general set of conclusions from the studies published to date, it is important to understand the methodology of each study, it purpose, the definition of non-compliance used and the way the results were analysed and described. This review summarizes the research into non-compliance in the contact lens field to data. A set of general conclusions is drawn and a model for compliance in the context of contact lens practice is proposed.

  9. Spherical aberration in contact lens wear.

    Science.gov (United States)

    Lindskoog Pettersson, A; Jarkö, C; Alvin, A; Unsbo, P; Brautaset, R

    2008-08-01

    The aim of the present studies was to investigate the effect on spherical aberration of different non custom-made contact lenses, both with and without aberration control. A wavefront analyser (Zywave, Bausch & Lomb) was used to measure the aberrations in each subject's right eye uncorrected and with the different contact lenses. The first study evaluated residual spherical aberration with a standard lens (Focus Dailies Disposable, Ciba Vision) and with an aberration controlled contact lens (ACCL) (Definition AC, Optical Connection Inc.). The second study evaluated the residual spherical aberrations with a monthly disposable silicone hydrogel lens with aberration reduction (PureVision, Bausch & Lomb). Uncorrected spherical aberration was positive for all pupil sizes in both studies. In the first study, residual spherical aberration was close to zero with the standard lens for all pupil sizes whereas the ACCL over-corrected spherical aberration. The results of the second study showed that the monthly disposable lens also over-corrected the aberration making it negative. The changes in aberration were statistically significant (plenses. Since the amount of aberration varies individually we suggest that aberrations should be measured with lenses on the eye if the aim is to change spherical aberration in a certain direction.

  10. A lazy way to design infrared lens

    Science.gov (United States)

    Qiu, RongSheng; Wu, JianDong; Chen, LongJiang; Yu, Kun; Pang, HaoJun; Hu, BaiZhen

    2017-08-01

    We designed a compact middle-wave infrared (MWIR) lens with a large focal length ratio (about 1.5:1), used in the 3.7 to 4.8 μm range. The lens is consisted of a compact front group and a re-imaging group. Thanks to the compact front group configuration, it is possible to install a filter wheel mechanism in such a tight space. The total track length of the lens is about 50mm, which includes a 2mm thick protective window and a cold shield of 12mm. The full field of view of the lens is about 3.6°, and F number is less than 1.6, the image circle is about 4.6mm in diameter. The design performance of the lens reaches diffraction limitation, and doesn't change a lot during a temperature range of -40°C +60°C. This essay proposed a stepwise design method of infrared optical system guided by the qualitative approach. The method fully utilize the powerful global optimization ability, with a little effort to write code snippet in optical design software, frees optical engineer from tedious calculation of the original structure.

  11. TESS Lens-Bezel Assembly Modal Testing

    Science.gov (United States)

    Dilworth, Brandon J.; Karlicek, Alexandra

    2017-01-01

    The Transiting Exoplanet Survey Satellite (TESS) program, led by the Kavli Institute for Astrophysics and Space Research at the Massachusetts Institute of Technology (MIT) will be the first-ever spaceborne all-sky transit survey. MIT Lincoln Laboratory is responsible for the cameras, including the lens assemblies, detector assemblies, lens hoods, and camera mounts. TESS is scheduled to be launched in August of 2017 with the primary goal to detect small planets with bright host starts in the solar neighborhood, so that detailed characterizations of the planets and their atmospheres can be performed. The TESS payload consists of four identical cameras and a data handling unit. Each camera consists of a lens assembly with seven optical elements and a detector assembly with four charge-coupled devices (CCDs) including their associated electronics. The optical prescription requires that several of the lenses are in close proximity to a neighboring element. A finite element model (FEM) was developed to estimate the relative deflections between each lens-bezel assembly under launch loads to predict that there are adequate clearances preventing the lenses from making contact. Modal tests using non-contact response measurements were conducted to experimentally estimate the modal parameters of the lens-bezel assembly, and used to validate the initial FEM assumptions. Key Words Non-contact measurements, modal analysis, model validation

  12. Complex PTSD and phased treatment in refugees: a debate piece

    Directory of Open Access Journals (Sweden)

    F. Jackie June ter Heide

    2016-02-01

    Full Text Available Background: Asylum seekers and refugees have been claimed to be at increased risk of developing complex posttraumatic stress disorder (complex PTSD. Consequently, it has been recommended that refugees be treated with present-centred or phased treatment rather than stand-alone trauma-focused treatment. This recommendation has contributed to a clinical practice of delaying or waiving trauma-focused treatment in refugees with PTSD. Objective: The aim of this debate piece is to defend two theses: (1 that complex trauma leads to complex PTSD in a minority of refugees only and (2 that trauma-focused treatment should be offered to all refugees who seek treatment for PTSD. Methods: The first thesis is defended by comparing data on the prevalence of complex PTSD in refugees to those in other trauma-exposed populations, using studies derived from a systematic review. The second thesis is defended using conclusions of systematic reviews and a meta-analysis of the efficacy of psychotherapeutic treatment in refugees. Results: Research shows that refugees are more likely to meet a regular PTSD diagnosis or no diagnosis than a complex PTSD diagnosis and that prevalence of complex PTSD in refugees is relatively low compared to that in survivors of childhood trauma. Effect sizes for trauma-focused treatment in refugees, especially narrative exposure therapy (NET and culturally adapted cognitive-behaviour therapy (CA-CBT, have consistently been found to be high. Conclusions: Complex PTSD in refugees should not be assumed to be present on the basis of complex traumatic experiences but should be carefully diagnosed using a validated interview. In line with treatment guidelines for PTSD, a course of trauma-focused treatment should be offered to all refugees seeking treatment for PTSD, including asylum seekers.

  13. Byzantine kalophonia, illustrated by St. John Koukouzeles’ piece

    Directory of Open Access Journals (Sweden)

    Maria Alexandru

    2012-01-01

    Full Text Available The present paper explores some aspects of the so-called kalophonic musical style which flourished during the last centuries of Byzantium. It focuses on a masterpiece by St. John Koukouzeles, namely the epibole Φρούρησον πανένδοξε (Ο Allglorious, keep watch over the city, in honor of St. Demetrios, the protector of Thessaloniki, and is complementary to some previous musicological analysis of this piece by Stephania Meralidou. After a brief presentation of the old sticheron Ἔχει μὲν ἡ θειοτάτη σου ψυχή, whereof St. John takes his departing point for the kalophonic composition, the paper concentrates on a multi-level analysis of the epibole, firstly on the ground of the late middle-Byzantine notation, according to the ms Vlatadon 46 (A.D. 1551, and secondly by comparing the old notation to its slow exegesis in new-Byzantine notation by Chourmouzios Chartophylax (score and recording issued by the Greek Byzantine Choir, dir. L. Angelopoulos.The analysis comprises several approaches like textual, music-architectural, modal, micro-syntactical, rhetorical, macro-syntactical, generative, comparative (cf. plates 7-12, 17-20. Since this material is also suitable for didactic purposes, the different plates are given again in the appendix, in form of exercises to be filled in by interested students.The different analytical approaches reveal the highly refined melodic fabric of kalophonia with its plethora of theseis-combinations, the extensive use of music-rhetorical devices, basic norms of the complex art of musical exegesis in this style, as well as the beauty of this kind of melodies, which have been acknowledged to represent the ‘zenith’ of Byzantine music (Wellesz.

  14. A One-Piece Lunar Regolith-Bag Garage Prototype

    Science.gov (United States)

    Smithers, Gweneth A.; Nehls, Mary K.; Hovater, Mary A.; Evans, Steven W.; Miller, J. Scott; Broughton, Roy M.; Beale, David; Killing-Balci, Fatma

    2007-01-01

    Shelter structures on the moon, even in early phases of exploration, should incorporate lunar materials as much as possible. We designed and constructed a prototype for a one-piece regolith-bag unpressurized garage concept, and, in parallel, we conducted a materials testing program to investigate six candidate fabrics to learn how they might perform in the lunar environment. In our concept, a lightweight fabric form is launched from Earth to be landed on the lunar surface and robotically filled with raw lunar regolith. In the materials testing program, regolith-bag fabric candidates included: Vectran(TM), Nextel(TM), Gore PTFE Fabric(TM), Zylon(TM), Twaron(TM), and Nomex(TM). Tensile (including post radiation exposure), fold, abrasion, and hypervelocity impact testing were performed under ambient conditions, and, within our current means, we also performed these tests under cold and elevated temperatures. In some cases, lunar simulant (JSC-1) was used in conjunction with testing. Our ambition is to continuously refine our testing to reach lunar environmental conditions to the extent possible. A series of preliminary structures were constructed during design of the final prototype. Design is based on the principles of the classic masonry arch. The prototype was constructed of Kevlar(TM) and filled with vermiculite (fairly close to the weight of lunar regolith on the moon). The structure is free-standing, but has not yet been load tested. Our plan for the future would be to construct higher fidelity mockups with each iteration, and to conduct appropriate tests of the structure.

  15. Research on Double CCD Dimensional Metrology Applying in Large Forge Piece

    International Nuclear Information System (INIS)

    Hu, C H; Xiong, Z

    2006-01-01

    As development of computer vision, stereoscopic vision sensors have been used more and more widely, and double CCD vision sensor with its simplicity of operator, highaccuracy and high-efficiency has been used in many spheres. It can be used in dimensional metrology of large forge piece, which greatly improves the efficiency and accuracy of large forge piece measurement

  16. Enumeration of pyramids of one-dimensional pieces of arbitrary fixed integer length

    DEFF Research Database (Denmark)

    Durhuus, Bergfinnur; Eilers, Søren

    We consider pyramids made of one-dimensional pieces of fixed integer length a and which may have pairwise overlaps of integer length from 1 to a. We prove that the number of pyramids of size m, i.e. consisting of m pieces, equals (am-1,m-1) for each a >= 2. This generalises a well known result...

  17. Bacteriological evaluation for one-and two-piece implant design supporting mandibular overdenture.

    Science.gov (United States)

    Abdelwahed, Ahmed; Mahrous, Ahmed I; Abadallah, Mohamed Farouk; Asfour, Hani; Aldawash, Hussien A; Alagha, Ebaa I

    2015-01-01

    This study evaluated and compared the bacteriological effect of two-piece implants and one-piece implants in complete overdenture cases on supporting structures. Ten male completely edentulous patients were selected and randomly divided into two equal groups according to the implant design and surgical technique for this study; Group 1: Patients were rehabilitated with complete mandibular overdenture supported by two-piece implants one on each side of the lower arch following two-stage surgical technique and Group 2: Patients were rehabilitated with complete mandibular overdenture supported by one-piece implants one on each side. Evaluation was made at the time of insertion, 6, 12, and 18 months after overdenture insertion, by measuring bacteriological changes around implants abutments. Complete overdenture supported by one-piece implants showed better effect on the bacteriological changes as compared to that supported by two-piece implants. Complete overdenture supported by one-piece implants one on each side of the lower arch showed better effect on the bacteriological changes than using the same prosthesis supported by two-piece implants.

  18. Successful mandible rehabilitation of lower incisors with one-piece implants.

    Science.gov (United States)

    Lauritano, Dorina; Grassi, Roberto; di Stasio, Dario; Lucchese, Alberta; Petruzzi, Massimo

    2014-12-05

    The popularity of one-piece implants has increased considerably among patients and dentists. The advantages of one-piece immediate loading are to reduce the number of interventions. These parameters can be better controlled with a one-piece implant. We considered 21 patients with one-piece implants inserted in mandible for this retrospective study. Inclusion criteria were: good oral hygiene, absence of lesions of the oral mucosa, no smoking or smoking less than 20 cigarettes a day, drinking less than two glasses of wine a day, good general health and no pregnancy. We enrolled 21 (12 women and 9 men) patients in this retrospective study. The mean follow-up was 1 year. A total of 84 one-piece implants were inserted in mandible to replace 42 lower first and 42 second incisors. The diameter of the implants was 3.0mm in all fixtures. The length of the implants was equal to or longer than 12 mm in 44 and 40 fixtures respectively. Of these, 48 were inserted in women and 36 in men (age range 33 to 67; mean age 58.3 years). There is no difference between the survival rates of one-piece immediate loading implants and two-piece implants and delayed loading. In conclusion, a one-piece immediate loading implant is a reliable device for mandible rehabilitation.

  19. Short- and Long-Term Musical Preferences: What Makes a Favourite Piece of Music?

    Science.gov (United States)

    Lamont, Alexandra; Webb, Rebecca

    2010-01-01

    Within the growing field of music preferences, little is currently known about the concept of a favourite piece of music. The current study explores listeners' nominated favourite pieces of music over short and longer time-spans, combining diary and interview methods to uncover what a favourite means, how stable it is, and what factors influence…

  20. Material Composition of Bucket Foundation Transition Piece for Offshore Wind Turbines

    DEFF Research Database (Denmark)

    Nezhentseva, Anastasia; Andersen, Lars; Ibsen, Lars Bo

    2010-01-01

    . This paper deals with the transition piece for a relatively novel type of foundation, the so-called suction bucket (caisson), focusing on the design of a transition piece connecting the turbine column with a suction bucket used as a monopod foundation for an offshore wind turbine. Since the current design...

  1. Piece2.0: an update for the pant gene structure comparison and evolution database

    Science.gov (United States)

    PIECE (Plant Intron Exon Comparison and Evolution) is a web-accessible database that houses intron and exon information of plant genes. PIECE serves as a resource for biologists interested in comparing intron–exon organization and provides valuable insights into the evolution of gene structure in pl...

  2. Acanthamoeba, bacterial, and fungal contamination of contact lens storage cases.

    Science.gov (United States)

    Gray, T B; Cursons, R T; Sherwan, J F; Rose, P R

    1995-01-01

    BACKGROUND--Microbial corneal infection is the most serious complication of contact lens wear. Contact lens cases are a recognised potential source of pathogens associated with corneal ulcers. METHODS--This survey established the incidence of protozoal, bacterial, and fungal contact lens case contamination in 101 asymptomatic daily wear cosmetic contact lens wearers from a domiciliary contact lens practice. RESULTS--Eighty two (81%) contact lens cases were found to be contaminated, with 19 (19%) sterile. Of all contact lens cases, 78 (77%) grew bacteria, 24 (24%) fungi, and 20 (20%) protozoa. Acanthamoeba spp were isolated from eight (8%) contact lens cases. Fifty six (55%) contact lens cases yielded mixed bacterial contamination. This is the first contact lens case survey in which hydrogen peroxide disinfection was the major method of contact lens disinfection (75% of subjects) and no home made saline was used. All the contaminating organisms were shown to possess the enzyme catalase that breaks down hydrogen peroxide to oxygen and water. The polymicrobial nature of the biofilms found in many contact lens cases is illustrated electron micrographically. CONCLUSION--Based on data from this and previous studies, the authors conclude with recommendations for contact lens wearers: (1) regular scrubbing of contact lens case interior to disrupt biofilms; (2) exposure of contact lens case to very hot water (> or = 70 degrees C) will kill Acanthamoeba contaminants; (3) allow contact lens case to air dry between uses; (4) if hydrogen peroxide disinfection is preferred, use a two step system; (5) replace contact lens case regularly. Images PMID:7626578

  3. The Alvarez-Lohmann lens as a do-nothing machine

    Science.gov (United States)

    Caulfield, H. John

    2002-02-01

    A do-nothing machine uses complex methods to convert an input pattern or function into an identical output pattern or function. They are of great interest because a selective modification somewhere within that machine can often accomplish useful results. Here, we start with the simplest possible optical system—a piece of glass split between the top and bottom by some simple or complex cut and rejoined perfectly. To light passing through, the cut does nothing. But, if we displace the top and bottom parts by some small amount, the combined system can serve as a variable thickness plate, a variable deflection angle prism, a variable focal length lens, etc. as first shown independently by Alvarez and Lohmann. This appears to be the first explanation of Alvarez-Lohmann lenses in such a simple way and it leads to the possibility of new structures not contemplated by either of the inventors.

  4. A modified-simple technique of removing the lens cortex during cataract surgery

    Directory of Open Access Journals (Sweden)

    Kyung Eun Han

    2017-01-01

    Full Text Available We describe here a surgical technique of removing the remaining cortex after phacoemulsification without performing the conventional irrigation/aspiration (I/A procedure. In this technique, the remaining cortex attached to the posterior capsule was separated and dissected into several pieces by continuous irrigation with balanced salt solution, which was supplied through a syringe attached to a bent, blunt-tip needle. Approximately, 10 s of manual irrigation separated most of the remaining cortex from the posterior capsule. Then, the capsular bag was inflated with an ophthalmic viscoelastic device (OVD, and this pushed the separated cortex toward the capsular fornix mechanically. An intraocular lens was inserted into the capsular bag, following which the remaining cortex and OVD were removed concomitantly using an automated I/A handpiece. This technique is a simple and easy maneuver to remove the cortex from all areas, including the subincisional area, and reduce the possibility of a posterior capsule tear.

  5. Characterization of lens based photoacoustic imaging system

    Directory of Open Access Journals (Sweden)

    Kalloor Joseph Francis

    2017-12-01

    Full Text Available Some of the challenges in translating photoacoustic (PA imaging to clinical applications includes limited view of the target tissue, low signal to noise ratio and the high cost of developing real-time systems. Acoustic lens based PA imaging systems, also known as PA cameras are a potential alternative to conventional imaging systems in these scenarios. The 3D focusing action of lens enables real-time C-scan imaging with a 2D transducer array. In this paper, we model the underlying physics in a PA camera in the mathematical framework of an imaging system and derive a closed form expression for the point spread function (PSF. Experimental verification follows including the details on how to design and fabricate the lens inexpensively. The system PSF is evaluated over a 3D volume that can be imaged by this PA camera. Its utility is demonstrated by imaging phantom and an ex vivo human prostate tissue sample.

  6. Freeform micromachining of an infrared Alvarez lens

    Science.gov (United States)

    Smilie, Paul J.; Dutterer, Brian S.; Lineberger, Jennifer L.; Davies, Matthew A.; Suleski, Thomas J.

    2011-02-01

    In 1967, Luis Alvarez introduced a novel concept for a focusing lens whereby two transmitting elements with cubic polynomial surfaces yield a composite lens of variable focal length with small lateral shifts. Computer simulations have demonstrated the behavior of these devices, but fabricating the refractive cubic surfaces of the types needed with adequate precision and depth modulation has proven to be challenging using standard methods, and, to the authors' knowledge, Alvarez lens elements have not been previously machined in infrared materials. Recent developments in freeform diamond machining capability have enabled the fabrication of such devices. In this paper, we discuss the fabrication of freeform refractive Alvarez elements in germanium using diamond micro-milling on a five-axis Moore Nanotech® 350FG Freeform Generator. Machining approaches are discussed, and measurements of surface figure and finish are presented. Initial experimental tests of optical performance are also discussed.

  7. Invited review article: the electrostatic plasma lens.

    Science.gov (United States)

    Goncharov, Alexey

    2013-02-01

    The fundamental principles, experimental results, and potential applications of the electrostatic plasma lens for focusing and manipulating high-current, energetic, heavy ion beams are reviewed. First described almost 50 years ago, this optical beam device provides space charge neutralization of the ion beam within the lens volume, and thus provides an effective and unique tool for focusing high current beams where a high degree of neutralization is essential to prevent beam blow-up. Short and long lenses have been explored, and a lens in which the magnetic field is provided by rare-earth permanent magnets has been demonstrated. Applications include the use of this kind of optical tool for laboratory ion beam manipulation, high dose ion implantation, heavy ion accelerator injection, in heavy ion fusion, and other high technology.

  8. 3D printed helical antenna with lens

    KAUST Repository

    Farooqui, Muhammad Fahad

    2016-12-19

    The gain of an antenna can be enhanced through the integration of a lens, however this technique has traditionally been restricted to planar antennas due to fabrication limitations of standard manufacturing processes. Here, with a unique combination of 3D and 2D inkjet printing of dielectric and metallic inks respectively, we demonstrate a Fresnel lens that has been monolithically integrated to a non-planar antenna (helix) for the first time. Antenna measurements show that the integration of a Fresnel lens enhances the gain of a 2-turn helix by around 4.6 dB giving a peak gain of about 12.9 dBi at 8.8 GHz.

  9. An "ESA-affordable" Laue-lens

    DEFF Research Database (Denmark)

    Lund, Niels

    2005-01-01

    With ESA's INTEGRAL mission gamma-ray astronomy has advanced to the point where major scientific advances must be expected from detailed studies of the many new point sources. The interest in developing focusing telescopes operating in the soft gamma-ray regime up to 1 MeV is therefore mounting r...... constraints of a specific medium size launch vehicle. The introduction of the lens mass as a primary design driver has some surprising effects for the choice of material for the crystals and new tradeoff considerations are introduced....... rapidly. Telescopes based on Laue diffraction of gamma-rays from crystals appear as one promising route, although the practical difficulties of realizing a large scale Laue lens are certainly not small. In this paper I have attempted to develop an optimized lens design considering the size and mass...

  10. Two-piece ALIF cage optimizes the bone-implant interface in a 360° setting.

    Science.gov (United States)

    Wilke, Hans-Joachim; Volkheimer, David; Robie, Bruce; Christensen, Finn B

    2017-11-01

    Clinical research has documented that cage subsidence and the loss of balance correction is a significant complication related to spinal fusion. Subsidence is a multifactorial complication, where implant design is one important element. The aim of the study is to compare the rigidity and bone-implant relative motion of segments treated with either a conventional one-piece ALIF cage versus a two-piece ALIF cage, which adapts in situ and permits 7°-21° of lordosis. Seven lumbosacral (L3-S1) human cadaver specimens were tested in a universal spine tester in the intact condition, the specimens instrumented with a two-piece ALIF cage (Statur ® -L, FBC Device, Denmark) and a one-piece ALIF cage (Pezo™-A, Ulrich GmbH & Co. KG., Germany), both supplemented with a pedicle screw system using pure moments of ±7.5 Nm in three principal motion directions. For assessment of the bone-implant interface, fluoroscopic videos were captured during motion and 3D motion was measured using an optical motion capturing system. Significantly less motion at the implant-endplate interface was found for the two-piece cage (1.0° ± 0.6°) in comparison to the one-piece cage (4.2° ± 1.7°) in flexion/extension. No significant differences in segment rigidity were found between the one-piece and two-piece cages in the 360° setup, while both configurations significantly reduced the range of motion compared to the intact condition (p one-piece ALIF cages, the two-piece cage concept reduced the relative motion at the bone-implant interface without compromising stability.

  11. The effectiveness of soft contact lens disinfection systems against Acanthamoeba on the lens surface.

    Science.gov (United States)

    Liedel, K K; Begley, C G

    1996-03-01

    This investigation compared the efficacy of three widely used contact lens disinfection systems against an ocular isolate of Acanthamoeba polyphaga. Twenty-seven worn Ciba NewVues lenses were quartered, heat sterilized and inoculated with Acanthamoeba. Lens quarters were then randomly assigned to three experimental groups, with Group A lenses exposed to cleaner and saline rinse only, Group B to disinfection only, and Group C to both cleaner and disinfection. One quarter of each lens served as a control and the other three quarters were experimental. Quantification of viable Acanthamoeba remaining on the lens was performed after each step of the disinfection process. Group A lenses showed no significant difference between the treatments, or the treatments and the control. Group B lenses demonstrated a significant difference (p = 0.0001) between the treatments and the control. In Group C (cleaning and disinfection), the control lens quarters were significantly different (p = 0.037) from the experimental group, but there was no significant difference between the treatments. All three disinfection regimens were very effective in reducing the number of viable Acanthamoeba on the contact lens surface. In the absence of proper cleaning (Group B), AOSept was the most effective of the three. These results also show the importance of thoroughly rubbing the contact lens surface to decrease the number of Acanthamoeba.

  12. Analytic models of plausible gravitational lens potentials

    International Nuclear Information System (INIS)

    Baltz, Edward A.; Marshall, Phil; Oguri, Masamune

    2009-01-01

    Gravitational lenses on galaxy scales are plausibly modelled as having ellipsoidal symmetry and a universal dark matter density profile, with a Sérsic profile to describe the distribution of baryonic matter. Predicting all lensing effects requires knowledge of the total lens potential: in this work we give analytic forms for that of the above hybrid model. Emphasising that complex lens potentials can be constructed from simpler components in linear combination, we provide a recipe for attaining elliptical symmetry in either projected mass or lens potential. We also provide analytic formulae for the lens potentials of Sérsic profiles for integer and half-integer index. We then present formulae describing the gravitational lensing effects due to smoothly-truncated universal density profiles in cold dark matter model. For our isolated haloes the density profile falls off as radius to the minus fifth or seventh power beyond the tidal radius, functional forms that allow all orders of lens potential derivatives to be calculated analytically, while ensuring a non-divergent total mass. We show how the observables predicted by this profile differ from that of the original infinite-mass NFW profile. Expressions for the gravitational flexion are highlighted. We show how decreasing the tidal radius allows stripped haloes to be modelled, providing a framework for a fuller investigation of dark matter substructure in galaxies and clusters. Finally we remark on the need for finite mass halo profiles when doing cosmological ray-tracing simulations, and the need for readily-calculable higher order derivatives of the lens potential when studying catastrophes in strong lenses

  13. Photonic crystal based polarization insensitive flat lens

    Science.gov (United States)

    Turduev, M.; Bor, E.; Kurt, H.

    2017-07-01

    The paper proposes a new design of an inhomogeneous artificially created photonic crystal lens structure consisting of annular dielectric rods to efficiently focus both transverse electric and transverse magnetic polarizations of light into the same focal point. The locations of each individual cell that contains the annular dielectric rods are determined according to a nonlinear distribution function. The inner and outer radii of the annular photonic dielectric rods are optimized with respect to the polarization insensitive frequency response of the transmission spectrum of the lens structure. The physical background of the polarization insensitive focusing mechanism is investigated in both spatial and frequency domains. Moreover, polarization independent wavefront transformation/focusing has been explored in detail by investigating the dispersion relation of the structure. Corresponding phase index distribution of the lens is attained for polarization insensitive normalized frequency range of a/λ  =  0.280 and a/λ  =  0.300, where a denotes the lattice constant of the designed structure and λ denotes the wavelength of the incident light. We show the wave transformation performance and focal point movement dynamics for both polarizations of the lens structure by specially adjusting the length of the structure. The 3D finite-difference time domain numerical analysis is also performed to verifiy that the proposed design is able to focus the wave regardless of polarization into approximately the same focal point (difference between focal distances of both polarizations stays below 0.25λ) with an operating bandwidth of 4.30% between 1476 nm and 1541 nm at telecom wavelengths. The main superiorities of the proposed lens structure are being all dielectric and compact, and having flat front and back surfaces, rendering the proposed lens design more practical in the photonic integration process in various applications such as optical switch

  14. Effect of infrared radiation on the lens

    Directory of Open Access Journals (Sweden)

    Aly Eman

    2011-01-01

    Full Text Available Background: Infrared (IR radiation is becoming more popular in industrial manufacturing processes and in many instruments used for diagnostic and therapeutic application to the human eye. Aim : The present study was designed to investigate the effect of IR radiation on rabbit′s crystalline lens and lens membrane. Materials and Methods: Fifteen New Zealand rabbits were used in the present work. The rabbits were classified into three groups; one of them served as control. The other two groups were exposed to IR radiation for 5 or 10 minutes. Animals from these two irradiated groups were subdivided into two subgroups; one of them was decapitated directly after IR exposure, while the other subgroup was decapitated 1 hour post exposure. IR was delivered from a General Electric Lamp model 250R 50/10, placed 20 cm from the rabbit and aimed at each eye. The activity of Na + -K + ATPase was measured in the lens membrane. Soluble lens proteins were extracted and the following measurements were carried out: estimation of total soluble protein, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE and Fourier transform infrared (FTIR spectroscopy. For comparison between multiple groups, analysis of variance was used with significance level set at P < 0.001. Results: The results indicated a change in the molecular weight of different lens crystalline accompanied with changes in protein backbone structure. These changes increased for the groups exposed to IR for 10 minutes. Moreover, the activity of Na + -K + ATPase significantly decreased for all groups. Conclusions: The protein of eye lens is very sensitive to IR radiation which is hazardous and may lead to cataract.

  15. The corneal stroma during contact lens wear.

    Science.gov (United States)

    Jalbert, Isabelle; Stapleton, Fiona

    2005-03-01

    Recent technological advances have lead to novel descriptions of the microanatomy of the corneal stroma. In the first section of this review, these findings and the role they play in the maintenance of vital properties such as corneal transparency, mechanical strength, homeostasis, wound-healing response and metabolism are described. In the second part, contact lens induced stromal alterations such as acidosis, oedema, striae, thinning and opacities are reviewed as well as the more recently described phenomenon of microdot deposits and keratocyte loss with an emphasis on how lens wearing stromal effects can be minimised.

  16. Sterilization potential of contact lens solutions

    Directory of Open Access Journals (Sweden)

    Dada Vijay

    1988-01-01

    Full Text Available In a dynamic field of Contact Lens Solutions maintenance of high standards of anti-microbial activity is a must Resterilization Activity Time′ is a universally accepted yardstick for such an evaluation. In this study eight brands of indigenous popular solutions alongwith two FDA approved solutions were tested for their sterilization efficacy: Standardized suspensions of Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans and Aspergillus fumigatus were used for the purpose. It was observed that the contact lens solutions available ir, the domestic market were not upto the mark Suggestions for improvement have also been made.

  17. Pulse transformer for the AA lithium lens

    CERN Document Server

    CERN PhotoLab

    1980-01-01

    The antiprotons emanating from the target were initially focused by a magnetic horn. Later on, a Li-lens was used during operation for the SPS collider, until 1992. A Li-rod (130 mm long, 34 mm in diameter) constituted the secondary of a 1:23 pulse-transformer. The half-sine pulse rose to 1000 kA in 900 microsec. The angular acceptance was 95 mrad. In operation after 1992, for LEAR only, a more modest Li-lens was used (155 mm long, diameter 20 mm, 480 kA, risetime 240 microsec, angular acceptance 75 mrad).

  18. Immunochemical analyses of soluble lens proteins in some marine fishes

    Digital Repository Service at National Institute of Oceanography (India)

    Menezes, M.R.

    Soluble eye lens proteins of 10 fishes, belonging to the families Clupeidae, Hemirhamphidae, Lactaridae, Scombridae, Stromatidae, Psettodidae, Bothidae and Soleidae were studied by immunoelectrophoresis using the lens antiserum of Sardinella...

  19. IOL Implants: Lens Replacement and Cataract Surgery (Intraocular Lenses)

    Science.gov (United States)

    ... Cataract Surgery vs. Laser-Assisted Cataract Surgery Cataract Vision Simulator Cataract Pictures and Videos: What Do ... Mar. 27, 2018 An intraocular lens (or IOL) is a tiny, artificial lens for the eye. It replaces the eye's ...

  20. Ambicor Two-Piece Inflatable Penile Prosthesis: Background and Contemporary Outcomes.

    Science.gov (United States)

    Ko, Oliver S; Bennett, Nelson E

    2018-04-01

    The two-piece inflatable penile prosthesis (IPP; Ambicor) might be a preferred option for men with erectile dysfunction (ED) who have significant retroperitoneal scarring, limited manual dexterity, or other issues. There are reported differences in outcomes and patient and partner satisfaction between three-piece and two-piece IPPs. To report contemporary outcomes, patient and partner satisfaction, and mechanical durability data of the two-piece compared with the three-piece IPP. A PubMed search was performed related to two-piece penile prostheses. Emphasis was placed on perioperative outcomes and patient and/or partner satisfaction scores. Non-English-language articles were excluded. Use of the Ambicor two-piece penile prosthesis was assessed by outlining the contemporary literature. The etiology of ED in this population, mechanical attributes, penile morphologic changes, satisfaction, and its use in special populations were reviewed. The most common etiology of ED for placement of the device remains a vasculogenic cause (range = 11-62%). Overall complication rates were 2.1% to 11.2% for the general population. Mechanical failure was seen in 0.7% to 6.1%. Infection rates were 0.7% to 4.8%. Spontaneous deflation was seen in approximately 25%. Higher complication rates were found in transgender patients after neophallus creation and the two-piece IPP could offer better durability compared with the three-piece IPP. Longer operative times, greater use of advanced dilation techniques, and greater length loss also have been reported. Overall satisfaction rates are higher than 85%. The predominant etiology of ED for two-piece penile prosthesis placement is vasculogenic. There is a trend toward IPP insertion in patients after radical prostatectomy or who have spinal cord injury. The two-piece device has similar complication rates and high patient satisfaction scores compared with three-piece IPPs. Further larger prospective studies are needed to validate our findings

  1. Modulation of lens cell adhesion molecules by particle beams

    Science.gov (United States)

    McNamara, M. P.; Bjornstad, K. A.; Chang, P. Y.; Chou, W.; Lockett, S. J.; Blakely, E. A.

    2001-01-01

    Cell adhesion molecules (CAMs) are proteins which anchor cells to each other and to the extracellular matrix (ECM), but whose functions also include signal transduction, differentiation, and apoptosis. We are testing a hypothesis that particle radiations modulate CAM expression and this contributes to radiation-induced lens opacification. We observed dose-dependent changes in the expression of beta 1-integrin and ICAM-1 in exponentially-growing and confluent cells of a differentiating human lens epithelial cell model after exposure to particle beams. Human lens epithelial (HLE) cells, less than 10 passages after their initial culture from fetal tissue, were grown on bovine corneal endothelial cell-derived ECM in medium containing 15% fetal bovine serum and supplemented with 5 ng/ml basic fibroblast growth factor (FGF-2). Multiple cell populations at three different stages of differentiation were prepared for experiment: cells in exponential growth, and cells at 5 and 10 days post-confluence. The differentiation status of cells was characterized morphologically by digital image analysis, and biochemically by Western blotting using lens epithelial and fiber cell-specific markers. Cultures were irradiated with single doses (4, 8 or 12 Gy) of 55 MeV protons and, along with unirradiated control samples, were fixed using -20 degrees C methanol at 6 hours after exposure. Replicate experiments and similar experiments with helium ions are in progress. The intracellular localization of beta 1-integrin and ICAM-1 was detected by immunofluorescence using monoclonal antibodies specific for each CAM. Cells known to express each CAM were also processed as positive controls. Both exponentially-growing and confluent, differentiating cells demonstrated a dramatic proton-dose-dependent modulation (upregulation for exponential cells, downregulation for confluent cells) and a change in the intracellular distribution of the beta 1-integrin, compared to unirradiated controls. In contrast

  2. Lens autofluorescence is not increased at high altitude

    DEFF Research Database (Denmark)

    Kessel, Line; Kofoed, Peter Kristian; Zubieta-Calleja, Gustavo

    2010-01-01

    PURPOSE: To study the relation between ambient environmental ultraviolet radiation exposure and lens fluorescence. METHODS: Non-invasive lens fluorometry measurements were compared in healthy Bolivian and Danish subjects. Background ultraviolet radiation was 4.5 times higher in Bolivia than in De...... living at sea level at 55 degrees northern latitude. These results suggest that lens ageing, as assessed by lens autofluorometry, is independent of exposure to ultraviolet radiation....

  3. Memory structures for encoding and retrieving a piece of music: an ERP investigation.

    Science.gov (United States)

    Williamon, Aaron; Egner, Tobias

    2004-12-01

    This study examined behavioral and neural correlates of expert musical memory, specifically the hypothesis that particular bars within a complex piece of music would serve as structural markers for encoding to and retrieval from memory. Six pianists were asked to learn and memorize a set prelude by J.S. Bach for performance, and to identify bars that they employed for structuring the prelude into component sections. Following performance from memory, the participants took part in a visual recognition memory task, in which single bars from the prelude had to be distinguished from matched new bars. During the recognition task, the electroencephalogram (EEG) was recorded, and event-related potentials (ERPs) from correctly identified prelude stimulus trials were averaged according to their hypothesized status into "structural" and "nonstructural" bars. The results showed that correct identification of structural bars was significantly faster (and tended to display higher accuracy) than recognition of non-structural ones. In addition, recognition of structural bars was associated with a significantly greater negative ERP peak of 300-400 ms latency and a right centro-parietal scalp distribution. This mid-latency negativity appears to index processing of stimuli that served as cues for encoding and retrieval of a complex semantic structure, and is qualitatively and conceptually different from other previously identified recognition memory ERPs (such as the "old/new" effect), as well as from the classic N400 ERP. The data support existing theories of expert memory and music cognition.

  4. Biological Width around One- and Two-Piece Implants Retrieved from Human Jaws

    Directory of Open Access Journals (Sweden)

    Ricardo Judgar

    2014-01-01

    Full Text Available Several histologic studies regarding peri-implant soft tissues and biological width around dental implants have been done in animals. However, these findings in human peri-implant soft tissues are very scarce. Therefore, the aim of this case series was to compare the biological width around unloaded one- and two-piece implants retrieved from human jaws. Eight partially edentulous patients received 2 test implants in the posterior mandible: one-piece (solid implants that comprise implant and abutment in one piece and two-piece (external hexagon with a healing abutment implants. After 4 months of healing, the implants and surrounding tissue were removed for histologic analysis. The retrieved implants showed healthy peri-implant bone and exhibited early stages of maturation. Marginal bone loss, gaps, and fibrous tissue were not present around retrieved specimens. The biologic width dimension ranged between 2.55 ± 0.16 and 3.26 ± 0.15 to one- and two-piece implants, respectively (P0.05. Within the limits of this study, it could be shown that two-piece implants resulted in the thickening of the connective tissue attachment, resulting in the increase of the biological width, when compared to one-piece implants.

  5. Biological width around one- and two-piece implants retrieved from human jaws.

    Science.gov (United States)

    Judgar, Ricardo; Giro, Gabriela; Zenobio, Elton; Coelho, Paulo G; Feres, Magda; Rodrigues, Jose A; Mangano, Carlo; Iezzi, Giovanna; Piattelli, Adriano; Shibli, Jamil Awad

    2014-01-01

    Several histologic studies regarding peri-implant soft tissues and biological width around dental implants have been done in animals. However, these findings in human peri-implant soft tissues are very scarce. Therefore, the aim of this case series was to compare the biological width around unloaded one- and two-piece implants retrieved from human jaws. Eight partially edentulous patients received 2 test implants in the posterior mandible: one-piece (solid implants that comprise implant and abutment in one piece) and two-piece (external hexagon with a healing abutment) implants. After 4 months of healing, the implants and surrounding tissue were removed for histologic analysis. The retrieved implants showed healthy peri-implant bone and exhibited early stages of maturation. Marginal bone loss, gaps, and fibrous tissue were not present around retrieved specimens. The biologic width dimension ranged between 2.55 ± 0.16 and 3.26 ± 0.15 to one- and two-piece implants, respectively (P 0.05). Within the limits of this study, it could be shown that two-piece implants resulted in the thickening of the connective tissue attachment, resulting in the increase of the biological width, when compared to one-piece implants.

  6. 21 CFR 886.1420 - Ophthalmic lens gauge.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic lens gauge. 886.1420 Section 886.1420...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1420 Ophthalmic lens gauge. (a) Identification. An ophthalmic lens gauge is a calibrated device intended to manually measure the curvature of a...

  7. In vivo study of lens regeneration in Rana cyanophlyctis under ...

    African Journals Online (AJOL)

    SAM

    2014-03-12

    Mar 12, 2014 ... enhanced the percentage lens regeneration not only in young tadpoles but also in froglets. Lens regeneration ability ... Influence of vitamin A and ascorbic acid on lens regeneration in young, mature tadpoles and froglets of the frog Rana cyanophlyctis. Group .... ingested by macrophages. Dorsal iris cells ...

  8. 21 CFR 800.10 - Contact lens solutions; sterility.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Contact lens solutions; sterility. 800.10 Section...) MEDICAL DEVICES GENERAL Requirements for Specific Medical Devices § 800.10 Contact lens solutions... ophthalmic use, including contact lens solutions, should be sterile. It is further evident that such...

  9. Initial Experience With Posterior Chamber Intraocular Lens Implant ...

    African Journals Online (AJOL)

    The results of extracapsular cataract extraction with posterior chamber intraocular lens implant at the Jos University Teaching Hospital are reviewed. The results suggest that despite lack of facilities to calculate the lens power for emmetropia, the use of a standard lens of about 19.0D will provide a good number of our ...

  10. Solar powered desalination system using Fresnel lens

    Science.gov (United States)

    Sales, M. T. B. F.

    2016-11-01

    The Philippines is surrounded by coastal areas and these areas can be a potential source for potable water. This study aims to design and construct a solar powered desalination system using Fresnel lens. The experimental study was conducted using polluted salt water for the sample and desalination was carried out using the designed system. The desalination system was composed of the solar concentrator, solar still and the condenser system. The Fresnel lens was made of acrylic plastic and was an effective solar concentrator. Solar stills made of dark colored glass bottles were effective in absorbing the solar energy. The condenser system made of polybutylene and polystyrene were effective in condensing the vapor at ambient temperature. The shortest time of vaporization of the salt water was at 293 sec and the optimum angle of position of the lens was 36.42°. The amount of condensate collected was directly proportional to the amount of salt water in the solar still. The highest mean efficiency of the designed set-up was 34.82%. The water produced by the solar powered desalination system using Fresnel lens passed the standards set by WHO (World Health Organization) for drinking water.

  11. Electronic states in a quantum lens

    International Nuclear Information System (INIS)

    Rodriguez, Arezky H.; Trallero-Giner, C.; Ulloa, S. E.; Marin-Antuna, J.

    2001-01-01

    We present a model to find analytically the electronic states in self-assembled quantum dots with a truncated spherical cap (''lens'') geometry. A conformal analytical image is designed to map the quantum dot boundary into a dot with semispherical shape. The Hamiltonian for a carrier confined in the quantum lens is correspondingly mapped into an equivalent operator and its eigenvalues and eigenfunctions for the corresponding Dirichlet problem are analyzed. A modified Rayleigh-Schro''dinger perturbation theory is presented to obtain analytical expressions for the energy levels and wave functions as a function of the spherical cap height b and radius a of the circular cross section. Calculations for a hard wall confinement potential are presented, and the effect of decreasing symmetry on the energy values and eigenfunctions of the lens-shape quantum dot is studied. As the degeneracies of a semicircular geometry are broken for b≠a, our perturbation approach allows tracking of the split states. Energy states and electronic wave functions with m=0 present the most pronounced influence on the reduction of the lens height. The method and expressions presented here can be straightforwardly extended to deal with more general Hamiltonians, including strains and valence-band coupling effects in Group III--V and Group II--VI self-assembled quantum dots

  12. Surgical treatment of hereditary lens subluxations.

    Science.gov (United States)

    Ozdek, Sengul; Sari, Ayca; Bilgihan, Kamil; Akata, Fikret; Hasanreisoglu, Berati

    2002-01-01

    To evaluate the effectiveness and results of pars plana vitreolensectomy approach with transscleral fixation of intraocular lens in hereditary lens subluxations. Fifteen eyes of 9 consecutive patients with a mean age of 12.8+/-6.2 years (6-26 years) with hereditary lens subluxation were operated on and the results were evaluated in a prospective study. Surgery was considered if best spectacle corrected visual acuity (BSCVA) was less than 20/70. All eyes underwent a 2-port pars plana vitreolensectomy and transscleral fixation of an intraocular lens (IOL). The mean follow-up period was 12.6+/-7.5 months (6-22 months). There was no major intraoperative complication. Preoperatively, 8 eyes (53.3%) had a BSCVA of counting fingers (CF) and 7 eyes (46.6%) had a BSCVA of 20/200 to 20/70. Postoperatively, 14 eyes (93.3%) had a BSCVA of 20/50 or better. None of the patients had IOL decentration or intraocular pressure (IOP) increase during the follow-up period. There was a macular hole formation in 1 eye postoperatively. The early results of pars plana vitreolensectomy with IOL implantation using scleral fixation technique had shown that it not only promises a rapid visual rehabilitation but it is also a relatively safe method. More serious complications, however, may occur in the long term.

  13. READING SCRIPTURE THROUGH A MYSTICAL LENS

    African Journals Online (AJOL)

    Reading scripture through a mystical lens. 144 the illuminatory function of scripture which confirms and explains experience, rather than in its philological or scientific status. Elisabeth often juxtaposes several texts when quoting from memory and the biblical foundation of her writings is clearly evident in certain cases which ...

  14. Corneal ring infiltration in contact lens wearers

    Directory of Open Access Journals (Sweden)

    Seyed Ali Tabatabaei

    2017-01-01

    Full Text Available To report a case of atypical sterile ring infiltrates during wearing soft silicone hydrogel contact lens due to poor lens care. A 29-year-old woman presented with complaints of pain, redness, and morning discharge. She was wearing soft silicone hydrogel contact lens previously; her current symptoms began 1 week before presentation. On examination, best-corrected visual acuity was 20/40 in that eye. Slit-lamp examination revealed dense, ring-shaped infiltrate involving both the superficial and deep stromal layers with lucid interval to the limbus, edema of the epithelium, epithelial defect, and vascularization of the superior limbus. Cornea-specific in vivo laser confocal microscopy (Heidelberg Retina Tomograph 2 Rostock Cornea Module, HRT 2-RCM, Heidelberg Engineering GmbH, Dossenheim, Germany revealed Langerhans cells and no sign of Acanthamoeba or fungal features, using lid scraping and anti-inflammatory drops; her vision completely recovered. We reported an atypical case of a sterile corneal ring infiltrate associated with soft contact lens wearing; smear, culture, and confocal microscopy confirmed a sterile inflammatory reaction.

  15. Final report on the UKAEA defect detection trials on test pieces 3 and 4. December 1982

    International Nuclear Information System (INIS)

    Lock, D.L.; Cowburn, K.J.

    1983-03-01

    The report follows ND-R-845(R) which described the scope, inspection procedures and results of the defect detection trials on test pieces 3 and 4. The work has been aimed at assessing the ability of non-destructive testing techniques, to detect and size defects near the clad/base metal interface of a flat piece and the inner radius of a PWR inlet nozzle. Following the destructive examination of the test pieces at Ispra, the true sizes of the intended defects are now known. These sizes are compared with that intended and the performance of the inspection teams reviewed. (author)

  16. Classification of delocalization power of global unitary operations in terms of LOCC one-piece relocalization

    Directory of Open Access Journals (Sweden)

    Akihito Soeda

    2010-06-01

    Full Text Available We study how two pieces of localized quantum information can be delocalized across a composite Hilbert space when a global unitary operation is applied. We classify the delocalization power of global unitary operations on quantum information by investigating the possibility of relocalizing one piece of the quantum information without using any global quantum resource. We show that one-piece relocalization is possible if and only if the global unitary operation is local unitary equivalent of a controlled-unitary operation. The delocalization power turns out to reveal different aspect of the non-local properties of global unitary operations characterized by their entangling power.

  17. Collide@CERN: exclusive open rehearsal of Gilles Jobin's last piece

    CERN Multimedia

    2012-01-01

    Collide@CERN and Gilles Jobin, artist in residency at CERN, present an exclusive open rehearsal of his last piece SPIDER GALAXIES Tuesday 31 July 2012 - A new piece created to open new territories of the mind - Join us in Restaurant 1 from 4 p.m. (next to the Glass Box Restaurant) With this piece, the body turns into matter, which is complete, spatial and sensual. Come and see Gilles Jobin and his dancers. With a score by Cristian Vogel and Carla Scaletti invoking sound particles, while Daniel Demont disperses the spectrum. Protean, infinitely large or infinitesimal, such are the Spider Galaxies.    

  18. Primary culture and growth characteristics of four different species of lens epithelial cells

    Directory of Open Access Journals (Sweden)

    Li-Xia Ji

    2015-07-01

    Full Text Available AIM: To explore the primary culture conditions for four kinds of lens epithelial cells(LECsof rat, rabbit, dog, and human, and measure their growth characteristics. METHODS: The lens capsule or anterior capsular tissue of rat, rabbit, dog and patient were removed by different methods, and they were cut into tiny pieces for primary culture by modified tissue adherent method. The morphological features of four kinds of LECs were observed under an inverted microscope.RESULTS: Four kinds of LECs of rat, rabbit, dog and human could be cultured primarily by tissue adherent method. With the evolution of tissue source, the adherent capacity of LECs gradually strengthened, cells form were changed from irregular polygon to oval, nucleus rounded and cytoplasm enriched gradually. Four kinds of LECs had fibrotic changes after several passages.CONCLUSION: LECs of rat, rabbit, dog and human can be primarily cultured. This method lays the foundation for the mechanism research of caratact and related fields on the cellular and molecular levels.

  19. Two-step technique for posterior optic buttonholing of intraocular lens.

    Science.gov (United States)

    Agarwal, Tushar; Jhanji, Vishal; Singh, Digvijay; Khokhar, Sudarshan

    2014-04-01

    This study aims to describe a two-step surgical technique for placement of a posterior chamber intraocular lens (IOL) in cases with crystalline lens subluxation resulting from non-progressive zonular dialysis. The first stage entails a phacoemulsification with creation of a 4-mm posterior capsular opening using an automated vitrector. The second stage performed 6 weeks later includes an anterior vitrectomy and injection of a foldable three-piece IOL in the sulcus. The haptics of IOL are positioned in the sulcus while the optic is pushed behind the posterior capsular opening therefore "buttonholing" the IOL. Seven eyes of seven patients with posttraumatic zonular dialysis were operated using this technique. Follow-up of all cases revealed a well-centered IOL with good postoperative visual acuity (20/20 to 20/80). Our two-stage surgical technique precludes the insertion of capsular tension ring in cases with non-progressive zonular dialysis. The technique is recommended in the presence of less than or equal to 6 clock hours of zonular dialysis with preexisting posterior capsular tear or herniation of vitreous in the anterior chamber.

  20. Properties of the cathode lens combined with a focusing magnetic/immersion-magnetic lens

    Czech Academy of Sciences Publication Activity Database

    Konvalina, Ivo; Müllerová, Ilona

    2011-01-01

    Roč. 645, č. 1 (2011), s. 55-59 ISSN 0168-9002 R&D Projects: GA ČR GAP102/10/1410; GA AV ČR IAA100650902; GA MŠk ED0017/01/01 Institutional research plan: CEZ:AV0Z20650511 Keywords : cathode lens * compound objective lens * aberration coefficients * spot size * field calculations Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.207, year: 2011

  1. Intrinsic lens potential of neural retina inhibited by Notch signaling as the cause of lens transdifferentiation.

    Science.gov (United States)

    Iida, Hideaki; Ishii, Yasuo; Kondoh, Hisato

    2017-01-15

    Embryonic neural retinas of avians produce lenses under spreading culture conditions. This phenomenon has been regarded as a paradigm of transdifferentiation due to the overt change in cell type. Here we elucidated the underlying mechanisms. Retina-to-lens transdifferentiation occurs in spreading cultures, suggesting that it is triggered by altered cell-cell interactions. Thus, we tested the involvement of Notch signaling based on its role in retinal neurogenesis. Starting from E8 retina, a small number of crystallin-expressing lens cells began to develop after 20 days in control spreading cultures. By contrast, addition of Notch signal inhibitors to cultures after day 2 strongly promoted lens development beginning at day 11, and a 10-fold increase in δ-crystallin expression level. After Notch signal inhibition, transcription factor genes that regulate the early stage of eye development, Prox1 and Pitx3, were sequentially activated. These observations indicate that the lens differentiation potential is intrinsic to the neural retina, and this potential is repressed by Notch signaling during normal embryogenesis. Therefore, Notch suppression leads to lens transdifferentiation by disinhibiting the neural retina-intrinsic program of lens development. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. CARBON-FIBRE-REINFORCED POLYMER PARTS EFFECT ON SPACECRAFT OPTOELECTRONIC MODULE LENS SCATTERING

    Directory of Open Access Journals (Sweden)

    S. S. Kolasha

    2016-01-01

    Full Text Available Spacecraft optoelectronic modules traditionally have aluminum alloy or titanium alloy casing which substantial weight increases fuel consumption required to put them into orbit and, consequently, total cost of the project. Carbon fiber reinforced polymer based composite constructive materials is an efficient solution that allows reducing weight and dimensions of large optoelectronic modules 1,5–3 times and the coefficient of linear thermal expansion 15–20 times if compared with metals. Optical characteristic is a crucial feature of carbon-fibre-reinforced polymer that determines composite material interaction with electromagnetic emission within the optical range. This work was intended to develop a method to evaluate Carbon fiber reinforced polymer optoelectronic modules casing effect on lens scattering by computer simulation with Zemax application software package. Degrees of scattered, reflected and absorbed radiant flux effect on imaging quality are described here. The work included experimental study in order to determine bidirectional reflectance distribution function by goniometric method for LUP-0.1 carbon fabric check test pieces of EDT-69U epoxy binder with EPOFLEX-0.4 glue layer and 5056-3.5-23-A aluminium honeycomb filler. The scattered emission was registered within a hemisphere above the check test piece surface. Optical detection direction was determined with zenith (0º < θ < 90º and azimuth (0º < φ < 180º angles with 10° increment. The check test piece surface was proved to scatter emission within a narrow angle range (approximately 20° with clear directivity. Carbon fiber reinforced polymers was found to feature integrated reflectance coefficient 3 to 4 times greater than special coatings do. 

  3. Nanosecond KTN varifocal lens without electric field induced phase transition

    Science.gov (United States)

    Zhu, Wenbin; Chao, Ju-Hung; Chen, Chang-Jiang; Campbell, Adrian; Henry, Michael; Yin, Stuart (Shizhuo); Hoffman, Robert C.

    2017-08-01

    This paper presents a nanosecond speed KTN varifocal lens. The tuning principle of varifocal lens is based on the high-speed refractive index modulation from the nanosecond speed tunable electric field. A response time on the order of nanoseconds was experimentally demonstrated, which is the fastest varifocal lens reported so far. The results confirmed that the tuning speed of the KTN varifocal lens could be significantly increased by avoiding the electric field induced phase transition. Such a nanosecond speed varifocal lens can be greatly beneficial for a variety of applications that demand high speed axial scanning, such as high-resolution 3D imaging and high-speed 3D printing.

  4. [Grades evaluation of Phellodendri chinensis cortex pieces based on quality constant].

    Science.gov (United States)

    Deng, Zhe; Jiao, Meng-Jiao; Zhang, Jun; Zhang, Qing; Cui, Wen-Jin; Shen, Li; Cheng, Jin-Tang; Liu, An

    2017-09-01

    Quality constant is a comprehensive grades evaluation method for traditional Chinese medicine decoction pieces, which is better but based on traditional way. In this paper, a new grading mode for Phellodendri chinensis pieces was established based on quality constant evaluation method. The results showed that the range of relative quality constant for 15 batches of different samples was from 0.41 to 0.96. As customary, if these samples were divided into three grades: the relative quality constant shall be ≥0.77 for first grade; quality constant mode can be used to effectively grade the P. chinensis pieces in a scientific, reasonable, objective and specific way. Simultaneously, it provided a beneficial reference for grading cortex herbal pieces or medicines. Copyright© by the Chinese Pharmaceutical Association.

  5. NICHD Research Networks Help Piece Together the Puzzle of Polycystic Ovary Syndrome

    Science.gov (United States)

    ... research networks help piece together the puzzle of polycystic ovary syndrome Many people think that scientific progress is ... Consider, for example the puzzling disorder known as polycystic ovary syndrome (PCOS) . Women with this condition produce high ...

  6. Acid phosphatase and lipid peroxidation in human cataractous lens epithelium

    Directory of Open Access Journals (Sweden)

    Vasavada Abhay

    1993-01-01

    Full Text Available The anterior lens epithelial cells undergo a variety of degenerative and proliferative changes during cataract formation. Acid phosphatase is primarily responsible for tissue regeneration and tissue repair. The lipid hydroperoxides that are obtained by lipid peroxidation of polysaturated or unsaturated fatty acids bring about deterioration of biological membranes at cellular and tissue levels. Acid phosphatase and lipid peroxidation activities were studied on the lens epithelial cells of nuclear cataract, posterior subcapsular cataract, mature cataract, and mixed cataract. Of these, mature cataractous lens epithelium showed maximum activity for acid phosphatase (516.83 moles of p-nitrophenol released/g lens epithelium and maximum levels of lipid peroxidation (86.29 O.D./min/g lens epithelium. In contrast, mixed cataractous lens epithelium showed minimum activity of acid phosphatase (222.61 moles of p-nitrophenol released/g lens epithelium and minimum levels of lipid peroxidation (54.23 O.D./min/g lens epithelium. From our study, we correlated the maximum activity of acid phosphatase in mature cataractous lens epithelium with the increased areas of superimposed cells associated with the formation of mature cataract. Likewise, the maximum levels of lipid peroxidation in mature cataractous lens epithelium was correlated with increased permeability of the plasma membrane. Conversely, the minimum levels of lipid peroxidation in mixed cataractous lens epithelium makes us presume that factors other than lipid peroxidation may also account for the formation of mixed type of cataract.

  7. In vitro performance of one- and two-piece zirconia implant systems for anterior application.

    Science.gov (United States)

    Kammermeier, Armin; Rosentritt, Martin; Behr, Michael; Schneider-Feyrer, Sibylle; Preis, Verena

    2016-10-01

    To investigate the long-term in vitro performance and fracture resistance of one-piece and bonded two-piece zirconia implant systems for anterior application. Two groups of bonded two-piece zirconia (ZZB), four groups of one-piece zirconia (Z), and two groups of two-piece titanium (TTS, reference) implant systems were restored with identical monolithic zirconia crowns (n=10/group). Eight specimens per group were mounted at an angle of 135° in the chewing simulator and subjected to thermal cycling (TC:18,000 cycles; 5°/55°) and mechanical loading (ML:3.6×10(6) cycles; 100N) simulating an anterior situation. Fracture resistance and maximum bending stress were determined for specimens that survived aging and for two references per group after 24h water storage. SEM pictures were used for failure analysis. Data were statistically analysed (one-way-ANOVA, post-hoc Bonferroni, Kaplan-Meier-Log-Rank, α=0.05). A one-piece zirconia and a two-piece titanium implant system survived TCML without failures. Both bonded two-piece zirconia implant systems and a one-piece zirconia implant system totally failed (fractures of abutment or implant). Failure numbers of the other systems varied between 1× (1 group) and 5× (2 groups). Significantly different survival rates were found (Log-Rank-test: p=0.000). Maximum fracture forces/bending stresses varied significantly ( p=0.000) between 188.00±44.80N/381.02±80.15N/mm(2) and 508.67±107.00N/751.45±36.73N/mm(2). Mean fracture values after 24h water storage and TCML were not significantly different. Zirconia implant systems partly showed material defects or connection insufficiencies. Bonded two-piece systems had higher failure rates and lower fracture resistance than one-piece implants. Individual zirconia implant systems may be applied in anterior regions with limitations. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Distance pieces for the mutual support of hexagonal fuel element boxes of a fast sodium-cooled breeder reactor

    International Nuclear Information System (INIS)

    Wild, E.

    1986-01-01

    All fuel elements are supported by distance pieces below and above the fuel zone. Each distance piece consists of two adjacent distance pieces of the same width and length, which are made of various materials. Stellite 6 with Inconel 718 or Hastelloy are particularly suitable as pairs of materials. These pairs of materials hardly tend to cold welding. (DG) [de

  9. Subjective assessment of contact lens wear by army aircrew.

    Science.gov (United States)

    Lattimore, M R; Cornum, R L

    1993-07-01

    Because 23% of Army aviators are ametropic, contact lenses have drawn increased attention as a spectacle substitute to solve system compatibility problems. From November 1988 until October 1991, a series of contact lens research protocols were conducted to develop a comprehensive database on contact lens wear in varied environments. Questionnaires were used to assess suitability and acceptability of routine contact lens wear. Responses from 202 subjects were obtained from September 1989 through September 1991. The questions explored operational and safety of flight issues of contact lens wear. Subjects overwhelmingly approved of contact lens use in all settings: 95% expressed greater combat readiness and effectiveness with contact lenses, 98% felt contact lens use (and maintenance) in the cockpit had no adverse impact on safety of flight, and 98% endorsed the routine use of contact lenses. These data highlight Army aircrew acceptance of contact lens use.

  10. Pars Plana Vitrectomy in Treatment of Lens Injury

    Directory of Open Access Journals (Sweden)

    Remzi Avcı

    2013-01-01

    Full Text Available Lens injury due to traumas may present as loss of capsule integrity, cataract, lens subluxation, or lens luxation. In addition, lens subluxation and lens luxation may occur in pseudophakic patients due to trauma. Clear corneal, scleral or sclero-corneal phacoemulsification surgery, pars plana vitrectomy, pars plana vitrectomy with phaco-fragmentation, or pars plana vitrectomy with removal through corneal incision techniques are used in the treatment of lens injury due to traumas. Intraocular lens can be implanted in the bag, sulcus, or anterior chamber during the surgery. Depending on the circumstances, scleral fixated intraocular lenses or iris-claw lenses may also be preferred. Rehabilitation of such patients is not of a great concern today, with the advanced level of vitreoretinal surgery and cataract surgery techniques and with the current state of technology. (Turk J Ophthalmol 2013; 43: 51-4

  11. An Automatic System of Testing the Best Stress of Installation for Semiconductor Refrigeration Piece

    Science.gov (United States)

    Chen, Hongyan; Song, Ping

    Concerning the problems of the impact on the factors of installation about semiconductor refrigeration piece are rarely studied in China and abroad, a reasonable structure of test device is designed, using stepper motor to test the temperature of the cold surface under different stress of installation to get the best stress of installation for the semiconductor refrigeration piece. Experiments shows that the system is of good noise immunity, high controlling and measuring precision.

  12. Piece rates and their effects on health and safety - a literature review.

    Science.gov (United States)

    Johansson, Bo; Rask, Kjell; Stenberg, Magnus

    2010-07-01

    The purpose of this study was to carry out a broad survey and analysis of relevant research articles about piece rate wages and their effects on health and safety that were published internationally until the fall of 2008. The aim was to summarize and describe the state of the art of the research in this field and if possible draw conclusions from the accumulated research results. A total of 75 research articles were examined extensively and 31 of these were found relevant and had sufficient quality to serve the purpose of this study. The findings of these relevant articles are summarized and analyzed in the survey. Since the late 1980s, there has been a change of research focus regarding piece rates and their effects on health and safety. More recent research shows a clear interest for health, musculoskeletal injuries, physical workload, pains and occupational injuries. The previous interest in risk behavior, security and accidents is still there, but no longer dominates the research scene. Although research is still sparse and fragmented, much of the accumulated knowledge about the effects of piece rate work tells us that piece rates in many situations have a negative effect on health and safety. The fact that 27 of the 31 studied articles found negative effects of piece rates on different aspects of health and safety does not prove causality, but together they give very strong support for the hypothesis that in most situations piece rates have negative effects on health and safety. In order to achieve better knowledge about the effects of piece rates in branches where piece rates are regarded problematic, further research is needed and such research has to be designed to meet the specific questions that are to be answered. Copyright 2010 Elsevier Ltd. All rights reserved.

  13. Application of gamma radiation to the nodes detection in Pinus Radiata (D.Don) wood pieces

    International Nuclear Information System (INIS)

    Morales, J.R.; Dinator, Maria I; Karsulovic C, Jose T.; Leon G, Adolfo

    1996-01-01

    Attenuation of 59.5 KeV photons provided by an Am-241 source, has been used to detect knots in lumber pieces from Pinus Radiata (D.Don). It is shown that the linear attenuation coefficient is a sensitive parameter to detect singularities in the structure of this material. The scanning of the piece provides profiles which define the position and extension of the singularity. (author)

  14. Nzikitanza – A piece on the resistance against the MUOS in Niscemi , Sicily

    Directory of Open Access Journals (Sweden)

    Marcello Messina

    2015-12-01

    Full Text Available Nzikitanza for accordion, violin, cello and tape was written in 2012 as a reflection on the deployment of Sicilian territory for NATO and US military operations. In particular, the piece was inspired by the then newly formed resistance committee against the MUOS in Niscemi. This brief commentary will illustrate a priori and a posteriori reflections on the status of the piece as a contribution to forms of antagonistic culture.

  15. Pay Matters: The Piece Rate and Health in the Developing World.

    Science.gov (United States)

    Davis, Mary E

    Piece rate pay remains a common form of compensation in developing-world industries. While the piece rate may boost productivity, it has been shown to have unintended consequences for occupational safety and health, including increased accident and injury risk. This paper explores the relationship between worker pay and physical and emotional health, and questions the modern day business case for piece rate pay in the developing world. The relationship between piece rate and self-reported measures of physical and emotional health is estimated using a large survey of garment workers in 109 Vietnamese factories between 2010 and 2014. A random effects logit model controls for factory and year, predicting worker health as a function of pay type, demographics, and factory characteristics. Workers paid by the piece report worse physical and emotional health than workers paid by the hour (OR = 1.38-1.81). Wage incentives provide the most consistently significant evidence of all demographic and factory-level variables, including the factory's own performance on occupational safety and health compliance measures. These results highlight the importance of how workers are paid to understanding the variability in worker health outcomes. More research is needed to better understand the business case supporting the continued use of piece rate pay in the developing world. Copyright © 2016 The Author. Published by Elsevier Inc. All rights reserved.

  16. [Application of relative quality constant in grades evaluation of Glycyrrizae Radix et Rhizome pieces].

    Science.gov (United States)

    Deng, Zhe; Jiao, Meng-Jiao; Zhang, Jun; Xian, Jing; Zhang, Qing; Chen, Chang; Wang, Yue-Sheng; Liu, An

    2017-07-01

    Quality constant evaluation is a comprehensive method for grades evaluation of traditional Chinese medicine pieces, but when it comes to Glycyrrizae Radix et Rhizome pieces, grades evaluation is diverged due to significant difference in contents of liquiritin and glycyrrhizic acid and unreasonable weight of index. To solve this problem, we have established a relative quality constant method in this paper to evaluate grades of Glycyrrizae Radix et Rhizome pieces. Twenty-nine batches of different quality samples were collected and tested, and finally, 17 batches of them were chosen as researcher objects. The results revealed that the range of the relative quality constant of these samples was from 1.78 to 11.49. When Glycyrrizae Radix et Rhizome pieces are divided into three grades: the relative quality constant of first grade is greater than or equal to 9.19; the second grade is greater than or equal to 5.75 but less than 9.19; while the third grade is less than 5.75. This research indicates that relative quality constant can divide the grades of herbal pieces in a scientific, reasonable, objective and specific way and remedy the shortage of quality constant perfectly. It provides a novel mode for grading pieces of Chinese medicine that contains multi-target ingredients. Copyright© by the Chinese Pharmaceutical Association.

  17. Thermal Lens Spectroscopy as a 'new' analytical tool for actinide determination in nuclear reprocessing processes

    International Nuclear Information System (INIS)

    Canto, Fabrice; Couston, Laurent; Magnaldo, Alastair; Broquin, Jean-Emmanuel; Signoret, Philippe

    2008-01-01

    Thermal Lens Spectroscopy (TLS) consists of measuring the effects induced by the relaxation of molecules excited by photons. Twenty years ago, the Cea already worked on TLS. Technologic reasons impeded. But, needs in sensitive analytical methods coupled with very low sample volumes (for example, traces of Np in the COEX TM process) and also the reduction of the nuclear wastes encourage us to revisit this method thanks to the improvement of optoelectronic technologies. We can also imagine coupling TLS with micro-fluidic technologies, decreasing significantly the experiments cost. Generally two laser beams are used for TLS: one for the selective excitation by molecular absorption (inducing the thermal lens) and one for probing the thermal lens. They can be coupled with different geometries, collinear or perpendicular, depending on the application and on the laser mode. Also, many possibilities of measurement have been studied to detect the thermal lens signal: interferometry, direct intensities variations, deflection etc... In this paper, one geometrical configuration and two measurements have been theoretically evaluated. For a single photodiode detection (z-scan) the limit of detection is calculated to be near 5*10 -6 mol*L -1 for Np(IV) in dodecane. (authors)

  18. Spontaneous dislocation of lens bag with acrylic lens after uneventful cataract surgery - unusual complication of cataract surgery.

    Science.gov (United States)

    Shah, Mehul A; Shah, Shreya M; Mehta, Ruchir; Shah, Prerna

    2015-01-01

    Spontaneous dislocation of intraocular lens with bag is rare. We report a case of a 56-year-old male who presented with spontaneous anterior dislocation of an in-the-bag intraocular lens 3 years after manual small incision cataract surgery. He had undergone manual small incision cataract surgery with foldable acrylic intraocular lens implantation, and 18 months after cataract surgery ND: YAG capsulotomy with uneventful post capsulotomy follow-up. 17 months after capsulotomy, the patient presented with sudden decrease of vision. On anterior segment examination, the intraocular lens with bag was dislocated into the anterior chamber. It was managed with intraocular lens explantation with bag, anterior vitrectomy and sclera fixated intraocular lens. Spontaneous intraocular lens dislocation with bag is possible after 1.5 years of uneventful surgery which may be managed using different techniques.

  19. Gravitational Lens Time Delays Using Polarization Monitoring

    Directory of Open Access Journals (Sweden)

    Andrew Biggs

    2017-11-01

    Full Text Available Gravitational lens time delays provide a means of measuring the expansion of the Universe at high redshift (and therefore in the ‘Hubble flow’ that is independent of local calibrations. It was hoped that many of the radio lenses found in the JVAS/CLASS survey would yield time delays as these were selected to have flat spectra and are dominated by multiple compact components. However, despite extensive monitoring with the Very Large Array (VLA, time delays have only been measured for three of these systems (out of 22. We have begun a programme to reanalyse the existing VLA monitoring data with the goal of producing light curves in polarized flux and polarization position angle, either to improve delay measurements or to find delays for new sources. Here, we present preliminary results on the lens system B1600+434 which demonstrate the presence of correlated and substantial polarization variability in each image.

  20. Complications caused by contact lens wearing.

    Science.gov (United States)

    Beljan, Jasna; Beljan, Kristina; Beljan, Zdravko

    2013-04-01

    Complications in wearing contact lenses are very rare and caused by poor maintenance, over-extended wear and wearing of contact lenses in a polluted environment. Regular control by a professional person can efficiently reduce the number of complications. This paper describes the most common risks factors for complications, and complications of wearing contact lenses with the classification according to the anatomic parts of the eye: eyelids, tear film, limbus, corneal epithelium, corneal stroma and corneal endothelium. Every complication has been described by the characteristic signs and symptoms, etiology and pathology, as well as therapy and prognosis. The paper describes how to select adequate customers as contact lens users, with proper education in order to ensure minimal incidence of complications due to contact lens wear, thus attracting a lot of satisfied and healthy customers.

  1. Effects of Temperature on Hybrid Lens Performance

    Science.gov (United States)

    Askins, Steve; Victoria, Marta; Herrero, Rebeca; Domínguez, César; Antón, Ignacio; Sala, Gabriel

    2011-12-01

    In hybrid Silicone-on-glass Fresnel lenses, an optical silicone is molded onto a glass substrate and forms the Fresnel structure. These lenses offer a cost effective solution as a primary optical element in point-focus concentrator photovoltaic modules, as well as performance advantages. However, these lenses have a high performance variation with temperature due both to the change in index of refraction of silicone as well as to deformations in the facets caused by coefficient of thermal expansion (CTE) mismatch. In this study we perform measurements of the light flux at the focal plane of a family of SOG lenses, varying temperature and lens-to-receiver distances. The effect of varying silicone cure temperature and the depth of the silicone between the lens and the glass substrate on temperature dependence was investigated. A preliminary computer model of this behavior is presented.

  2. A Tribute to Dr. Willy Lens

    Directory of Open Access Journals (Sweden)

    Maarten Vansteenkiste

    2016-07-01

    Full Text Available Dr. Willy Lens, born on December 10th, 1943, passed away on August 29th, 2014. With his passing, the motivation community has lost a seminal member, a mentor, and a friend. Dr. Lens – a Fellow of the Association for Psychological Science and Founding Fellow of the American Educational Research Association – made fundamental contributions to the study of motivation both through his own work and through his caring and thoughtful mentorship of a large community of scholars. With this tribute, we want to honor Dr. Willy Lens’ significance to psychology and education as well as his positive influence, both personally and professionally, on the lives of dozens of scholars. With his contagious enthusiasm and caring mentorship, Willy was an example for our academic community and with this tribute we express our gratitude for the privilege to have collaborated with him.

  3. Stretched Lens Array Photovoltaic Concentrator Technology Developed

    Science.gov (United States)

    Piszczor, Michael F., Jr.; O'Neill, Mark J.

    2004-01-01

    Solar arrays have been and continue to be the mainstay in providing power to nearly all commercial and government spacecraft. Light from the Sun is directly converted into electrical energy using solar cells. One way to reduce the cost of future space power systems is by minimizing the size and number of expensive solar cells by focusing the sunlight onto smaller cells using concentrator optics. The stretched lens array (SLA) is a unique concept that uses arched Fresnel lens concentrators to focus sunlight onto a line of high-efficiency solar cells located directly beneath. The SLA concept is based on the Solar Concentrator Array with Refractive Linear Element Technology (SCARLET) design that was used on NASA's New Millennium Deep Space 1 mission. The highly successful asteroid/comet rendezvous mission (1998 to 2001) demonstrated the performance and long-term durability of the SCARLET/SLA solar array design and set the foundation for further improvements to optimize its performance.

  4. Intraocular lens implantation in microphthalmic patients.

    Science.gov (United States)

    Sinskey, R M; Amin, P; Stoppel, J

    1992-09-01

    Microphthalmos is a developmental disorder of the eye consisting of a smaller than normal eye. This disorder can present as an isolated condition or associated with other systemic alterations. It is not uncommon for patients with microphthalmos to have congenital cataracts along with other ocular and systemic abnormalities. This paper reports the experience with 11 microphthalmic eyes of seven patients who had primary or secondary intraocular lens (IOL) implantation over a six-year period from 1985 to 1991. In all cases the IOL had a 13.5 mm or 14.0 mm overall diameter and a 6.0 mm or 6.5 mm optic. It was difficult to obtain documentation of objective visual improvement in many of these cases because of the associated nystagmus. However, all patients reported subjective improvements. These results suggest that with proper technique and lens selection microphthalmic patients should be considered for IOL implantation with relative safety and success.

  5. Pulser for the Tevatron electron lens gun

    Energy Technology Data Exchange (ETDEWEB)

    Iouri Terechkine et al.

    2004-05-18

    To compensate for beam-beam interaction in Tevatron, an ''electron lens'' is considered to be an effective instrument. When a bunch of electrons with energy in the range (10-16) kV is overlapping with a bunch of antiprotons, the resulting focusing force for antiprotons can be adjusted by changing the electron beam current and by profiling its radial distribution. There exist several scenarios of how the system must function. According to one of them, an electron gun that supplies electrons must be fed by voltage pulses that follow with the frequency of antiproton bunches circulating in the Tevatron, which is about 2.5 MHz. To provide focusing tailored for each individual antiproton bunch, a modulator of the gun (pulser) must allow pulse-to-pulse voltage change. This report will cover main approaches to a design of a pulser for use with the gun of the Tevatron Electron Lens.

  6. Intraocular Lens Subluxation in Marfan Syndrome

    Science.gov (United States)

    Rodrigo, Bolaños-Jiménez; Paulina, López-Lizárraga E; Francesc, March de R; Eduardo, Telich-Tarriba J; Alejandro, Navas

    2014-01-01

    Purpose : Ectopia lentis (EL) is a major criteria for the diagnosis of Marfan syndrome, it may vary from an asymptomatic mild displacement to a significant subluxation that places the equator of the lens in the pupillary axis. The purpose of this work is to present the case of a patient with Marfan syndrome who received treatment for subluxation at our institution. Case Report : A 51-year-old female diagnosed with Marfan syndrome presented to the emergency department with bilateral eye redness, foreign body sensation and crusting around the eyes on awakening. She had the following history of cardiac and ophthalmologic complications, including: 1. Lens subluxation 2. High myopia 3. Aortic root dilation, 4. Mitral valve prolapse and 5. Tricuspid insufficiency. Conclusion : The ophthalmological management of Marfan patients is challenging and periodical follow-up is needed. Surgical versus conservative management is controversial, each case needs to be evaluated individually to analyze the risks and benefits of the procedures. PMID:25279020

  7. Pieced Together: Collage as an Artist's Method for Interdisciplinary Research

    Directory of Open Access Journals (Sweden)

    Kathleen Vaughan

    2005-03-01

    Full Text Available As a visual artist undertaking doctoral studies in education, the author required a research method that integrated her studio practice into her research process, giving equal weight to the visual and the linguistic. Her process of finding such a method is outlined in this article, which touches on arts-based research and practice-led research, and her ultimate approach of choice, collage. Collage, a versatile art form that accommodates multiple texts and visuals in a single work, has been proposed as a model for a “borderlands epistemology”: one that values multiple distinctive understandings and that deliberately incorporates nondominant modes of knowing, such as visual arts. As such, collage is particularly suited to a feminist, postmodern, postcolonial inquiry. This article offers a preliminary theorizing of collage as a method and is illustrated with images from the author's research/visual practice.

  8. Sterilization potential of contact lens solutions

    OpenAIRE

    Dada Vijay; Mehta Manoj

    1988-01-01

    In a dynamic field of Contact Lens Solutions maintenance of high standards of anti-microbial activity is a must Resterilization Activity Time′ is a universally accepted yardstick for such an evaluation. In this study eight brands of indigenous popular solutions alongwith two FDA approved solutions were tested for their sterilization efficacy: Standardized suspensions of Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans and Aspergillus fumigatus were used for the purpose. ...

  9. Performance of a Be Refractive Lens

    International Nuclear Information System (INIS)

    Smither, R.K.; Khounsary, A.M.; Mancini, D.C.; Saleem, K. Abu

    2004-01-01

    The performance of a beryllium compound refractive lens (CRL) was tested in the energy range of 11.5 to 8.0 keV. The beryllium refractive lens consists of 50 aligned, 1-mm-diameter, hollow spheres in a solid block of beryllium, 30 mm x 20 mm x 55 mm. The minimum web between each hollow sphere was 0.10 mm. The measured focal length of the lens for x-rays close to the axis of the beam was 147.7 cm +/- 2.0 cm at 10 keV and 120.2 +/- 2.0 cm at 9.1 keV. These values agree well with the theoretical values of 146.6 cm and 121.4 cm, respectively. The diameter of the best focus obtained at 10 keV was 35 μm horizontal and 45 μm vertical. For the modified version of the lens used in the 9.1 keV experiment these values were 25 μm horizontal and 35 μm vertical. The x-ray beam cross section for the 10 keV and the 9.1 keV experiments were 0.50 mm x 0.50 mm and 0.30 mm x 0.30 mm, respectively. The enhancement of the flux (photons per sq. mm) was 50:1 at 10 keV and 80:1 in the 9.1 keV experiment

  10. THE BOSS EMISSION-LINE LENS SURVEY. IV. SMOOTH LENS MODELS FOR THE BELLS GALLERY SAMPLE

    Energy Technology Data Exchange (ETDEWEB)

    Shu, Yiping [National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing 100012 (China); Bolton, Adam S.; Montero-Dorta, Antonio D.; Cornachione, Matthew A.; Zheng, Zheng; Brownstein, Joel R. [Department of Physics and Astronomy, University of Utah, 115 South 1400 East, Salt Lake City, UT 84112 (United States); Mao, Shude [Physics Department and Tsinghua Centre for Astrophysics, Tsinghua University, Beijing 100084 (China); Kochanek, Christopher S. [Department of Astronomy and Center for Cosmology and Astroparticle Physics, Ohio State University, Columbus, OH 43210 (United States); Pérez-Fournon, Ismael; Marques-Chaves, Rui [Instituto de Astrofísica de Canarias, C/Vía Láctea, s/n, E-38205 San Cristóbal de La Laguna, Tenerife (Spain); Oguri, Masamune [Research Center for the Early Universe, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Ménard, Brice, E-mail: yiping.shu@nao.cas.cn [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States)

    2016-12-20

    We present Hubble Space Telescope F606W-band imaging observations of 21 galaxy-Ly α emitter lens candidates in the Baryon Oscillation Spectroscopic Survey Emission-Line Lens Survey (BELLS) for the GALaxy-Ly α EmitteR sYstems (BELLS GALLERY) survey. Seventeen systems are confirmed to be definite lenses with unambiguous evidence of multiple imaging. The lenses are primarily massive early-type galaxies (ETGs) at redshifts of approximately 0.55, while the lensed sources are Ly α emitters (LAEs) at redshifts from two to three. Although most of the lens systems are well fit by smooth lens models consisting of singular isothermal ellipsoids in an external shear field, a thorough exploration of dark substructures in the lens galaxies is required. The Einstein radii of the BELLS GALLERY lenses are, on average, 60% larger than those of the BELLS lenses because of the much higher source redshifts. This will allow for a detailed investigation of the radius evolution of the mass profile in ETGs. With the aid of the average ∼13× lensing magnification, the LAEs are frequently resolved into individual star-forming knots with a wide range of properties. They have characteristic sizes from less than 100 pc to several kiloparsecs, rest-frame far-UV apparent AB magnitudes from 29.6 to 24.2, and typical projected separations of 500 pc to 2 kpc.

  11. [Congenital lens subluxation: visual acuity outcomes and intraocular lens postoperative position].

    Science.gov (United States)

    Arraes, Caroline; Endriss, Daniela; Lobato, Francisco; Arraes, João; Ventura, Marcelo

    2010-01-01

    To evaluate the visual acuity outcomes and to investigate the intraocular lens (IOL) and endocapsular ring positions with ultrasound biomicroscopy in 17 eyes of 10 patients with congenital lens subluxation who underwent the same surgical technique, by the same surgeon. The study was performed in the ''Hospital de Olhos de Pernambuco'' and ''Fundação Altino Ventura''. The surgical technique consisted of phacoaspiration with implant of endocapsular ring and intraocular lens with one loop haptic amputated. The age varied from 7 to 22 years. Data on visual acuity (VA) before and after surgery, surgery follow-up period, and complications were analyzed. All patients underwent ultrasound biomicroscopy. The mean follow-up period was 2.8 years. There was a VA improvement in 17 (100%) eyes: in 12 eyes (70.6%) the visual acuity was better than 20/40; 4 (23.5%) ranged from 20/40 to 20/100, and 1 (5.9%) had visual acuity worse than 20/100, however better than the preoperative visual acuity. The posterior capsular opacification occurred in 10 eyes (58.9%). Ultrasound biomicroscopy showed that all IOL were partially decentralized, however without surpassing the pupil border limit. Endocapsular ring position was correct and there was a good capsular support in all cases. The evaluated surgical treatment provided good intraocular lens and endocapsular ring position, with VA improvement Thus, this technique is a viable, effective and safe option for the visual rehabilitation of patients with congenital lens subluxation.

  12. Two families of astrophysical diverging lens models

    Science.gov (United States)

    Er, Xinzhong; Rogers, Adam

    2018-03-01

    In the standard gravitational lensing scenario, rays from a background source are bent in the direction of a foreground lensing mass distribution. Diverging lens behaviour produces deflections in the opposite sense to gravitational lensing, and is also of astrophysical interest. In fact, diverging lensing due to compact distributions of plasma has been proposed as an explanation for the extreme scattering events that produce frequency-dependent dimming of extragalactic radio sources, and may also be related to the refractive radio wave phenomena observed to affect the flux density of pulsars. In this work we study the behaviour of two families of astrophysical diverging lenses in the geometric optics limit, the power law, and the exponential plasma lenses. Generally, the members of these model families show distinct behaviour in terms of image formation and magnification, however the inclusion of a finite core for certain power-law lenses can produce a caustic and critical curve morphology that is similar to the well-studied Gaussian plasma lens. Both model families can produce dual radial critical curves, a novel distinction from the tangential distortion usually produced by gravitational (converging) lenses. The deflection angle and magnification of a plasma lens vary with the observational frequency, producing wavelength-dependent magnifications that alter the amplitudes and the shape of the light curves. Thus, multiwavelength observations can be used to physically constrain the distribution of the electron density in such lenses.

  13. Dynamic metasurface lens based on MEMS technology

    Directory of Open Access Journals (Sweden)

    Tapashree Roy

    2018-02-01

    Full Text Available In the recent years, metasurfaces, being flat and lightweight, have been designed to replace bulky optical components with various functions. We demonstrate a monolithic Micro-Electro-Mechanical System (MEMS integrated with a metasurface-based flat lens that focuses light in the mid-infrared spectrum. A two-dimensional scanning MEMS platform controls the angle of the lens along two orthogonal axes by ±9°, thus enabling dynamic beam steering. The device could be used to compensate for off-axis incident light and thus correct for aberrations such as coma. We show that for low angular displacements, the integrated lens-on-MEMS system does not affect the mechanical performance of the MEMS actuators and preserves the focused beam profile as well as the measured full width at half maximum. We envision a new class of flat optical devices with active control provided by the combination of metasurfaces and MEMS for a wide range of applications, such as miniaturized MEMS-based microscope systems, LIDAR scanners, and projection systems.

  14. Adaptive Liquid Lens Actuated by Droplet Movement

    Directory of Open Access Journals (Sweden)

    Chao Liu

    2014-08-01

    Full Text Available In this paper we report an adaptive liquid lens actuated by droplet movement. Four rectangular PMMA (Polymethyl Methacrylate substrates are stacked to form the device structure. Two ITO (Indium Tin Oxide sheets stick on the bottom substrate. One PMMA sheet with a light hole is inserted in the middle of the device. A conductive droplet is placed on the substrate and touches the PMMA sheet to form a small closed reservoir. The reservoir is filled with another immiscible non-conductive liquid. The non-conductive liquid can form a smooth concave interface with the light hole. When the device is applied with voltage, the droplet stretches towards the reservoir. The volume of the reservoir reduces, changing the curvature of the interface. The device can thus achieve the function of an adaptive lens. Our experiments show that the focal length can be varied from −10 to −159 mm as the applied voltage changes from 0 to 65 V. The response time of the liquid lens is ~75 ms. The proposed device has potential applications in many fields such as information displays, imaging systems, and laser scanning systems.

  15. Compound refractive X-ray lens

    International Nuclear Information System (INIS)

    Nygren, D.R.; Cahn, R.; Cederstrom, B.; Danielsson, M.; Vestlund, J.

    2000-01-01

    An apparatus and method are disclosed for focusing X-rays. In one embodiment, his invention is a commercial-grade compound refractive X-ray lens. The commercial-grade compound refractive X-ray lens includes a volume of low-Z material. The volume of low-Z material has a first surface which is adapted to receive X-rays of commercially-applicable power emitted from a commercial-grade X-ray source. The volume of low-Z material also has a second surface from which emerge the X-rays of commercially-applicable power which were received at the first surface. Additionally, the commercial-grade compound refractive X-ray lens includes a plurality of openings which are disposed between the first surface and the second surface. The plurality of openings are oriented such that the X-rays of commercially-applicable power which are received at the first surface, pass through the volume of low-Z material and through the plurality openings. In so doing, the X-rays which emerge from the second surface are refracted to a focal point

  16. Laboratory Demonstration of Axicon-Lens Coronagraph

    Science.gov (United States)

    Choi, Jaeho; Jea, Geonho

    2018-01-01

    The results of laboratory based experiments of the proposed coronagraph using axicon-lenses that is conjunction with a method of noninterferometric quantitative phase imaging for direct imaging of exoplanets is will present. The light source is passing through tiny holes drilled on the thin metal plate is used as the simulated stellar and its companions. Those diffracted light at the edge of the holes bears a similarity to the light from the bright stellar. Those images are evaginated about the optical axis after the maximum focal length of the first axicon lens. Then the evaginated images of have cut off using the motorized iris which means the suppressed the central stellar light preferentially. Various length between the holes which represent the angular distance are examined. The laboratory experimental results are shown that the axicon-lens coronagraph has feature of ability to achieve the smaller IWA than l/D and high-contrast direct imaging. The laboratory based axicon-lens coronagraph imaging support the symbolic computation results which has potential in direct imaging for finding exoplanet and various astrophysical activities. The setup of the coronagraph is simple to build and is durable to operate. Moreover it can be transported the planets images to a broadband spectrometric instrument that able to investigate the constituent of the planetary system.

  17. Metasurface axicon lens design at visible wavelengths

    Science.gov (United States)

    Alyammahi, Saleimah; Zhan, Qiwen

    2017-08-01

    The emerging field of metasurfaces is promising to realize novel optical devices with miniaturized flat format and added functionalities. Metasurfaces have been demonstrated to exhibit full control of amplitude, phase and polarization of electromagnetic waves. Using the metasurface, the wavefront of light can be manipulated permitting new functionalities such as focusing and steering of the beams and imaging. One optical component which can be designed using metasurfaces is the axicon. Axicons are conical lenses used to convert Gaussian beams into nondiffraction Bessel beams. These unique devices are utilized in different applications ranging from optical trapping and manipulation, medical imaging, and surgery. In this work, we study axicon lens design comprising of planar metasurfaces which generate non-diffracting Bessel beams at visible wavelengths. Dielectric metasurfaces have been used to achieve high efficiency and low optical loss. We measured the spot size of the resulted beams at different planes to demonstrate the non-diffraction properties of the resulted beams. We also investigated how the spot size is influenced by the axicon aperture. Furthermore, we examined the achromatic properties of the designed axicon. Comparing with the conventional lens, the metasurface axicon lens design enables the creation of flat optical device with wide range of depth of focus along its optical axis.

  18. Radiation dose to the eye lens

    DEFF Research Database (Denmark)

    Baun, Christina; Falch Braas, Kirsten; D. Nielsen, Kamilla

    2015-01-01

    Radiation Dose to the Eye Lens: Does Positioning Really Matter? C. Baun1, K. Falch1, K.D. Nielsen2, S. Shanmuganathan1, O. Gerke1, P.F. Høilund-Carlsen1 1Department of Nuclear Medicine, Odense University Hospital, Odense C, Denmark. 2University College Lillebaelt, Odense, Denmark. Aim: The scan...... field in oncology patients undergoing eyes-to-thighs PET/CT must always include the base of the scull according to department guidelines. The eye lens is sensitive to radiation exposure and if possible it should be avoided to scan the eye. If the patient’s head is kipped backwards during the scan one...... might avoid including the eye in the CT scan without losing sufficient visualization of the scull base. The aim of this study was to evaluate the possibility of decreasing the radiation dose to the eye lens, simply by changing the head position, when doing the PET/CT scan from the base of the scull...

  19. Dynamic metasurface lens based on MEMS technology

    Science.gov (United States)

    Roy, Tapashree; Zhang, Shuyan; Jung, Il Woong; Troccoli, Mariano; Capasso, Federico; Lopez, Daniel

    2018-02-01

    In the recent years, metasurfaces, being flat and lightweight, have been designed to replace bulky optical components with various functions. We demonstrate a monolithic Micro-Electro-Mechanical System (MEMS) integrated with a metasurface-based flat lens that focuses light in the mid-infrared spectrum. A two-dimensional scanning MEMS platform controls the angle of the lens along two orthogonal axes by ±9°, thus enabling dynamic beam steering. The device could be used to compensate for off-axis incident light and thus correct for aberrations such as coma. We show that for low angular displacements, the integrated lens-on-MEMS system does not affect the mechanical performance of the MEMS actuators and preserves the focused beam profile as well as the measured full width at half maximum. We envision a new class of flat optical devices with active control provided by the combination of metasurfaces and MEMS for a wide range of applications, such as miniaturized MEMS-based microscope systems, LIDAR scanners, and projection systems.

  20. Radiation dose to the lens and cataract formation

    International Nuclear Information System (INIS)

    Henk, J.M.; Whitelocke, R.A.F.; Warrington, A.P.; Bessell, E.M.

    1993-01-01

    The purpose of this work was to determine the radiation tolerance of the lens of the eye and the incidence of radiation-induced lens changes in patients treated by fractionated supervoltage radiation therapy for orbital tumors. Forty patients treated for orbital lymphoma and pseudotumor with tumor doses of 20--40 Gy were studied. The lens was partly shielded using lead cylinders in most cases. The dose to the germinative zone of the lens was estimated by measurements in a tissue equivalent phantom using both film densitometry and thermoluminescent dosimetry. Opthalmological examination was performed at 6 monthly intervals after treatment. The lead shield was found to reduce the dose to the germinative zone of the lens to between 36--50% of the tumor dose for Cobalt beam therapy, and to between 11--18% for 5 MeV x-rays. Consequently, the lens doses were in the range 4.5--30 Gy in 10--20 fractions. Lens opacities first appeared from between 3 and 9 years after irradiation. Impairment of visual acuity ensued in 74% of the patients who developed lens opacities. The incidence of lens changes was strongly dose-related. None was seen after doses of 5 Gy or lower, whereas doses of 16.5 Gy or higher were all followed by lens opacities which impaired visual acuity. The largest number of patients received a maximum lens dose of 15 Gy; in this group the actuarial incidence of lens opacities at 8 years was 57% with visual impairment in 38%. The adult lens can tolerate a total dose of 5 Gy during a fractionated course of supervoltage radiation therapy without showing any changes. Doses of 16.5 Gy or higher will almost invariably lead to visual impairment. The dose which causes a 50% probability of visual impairment is approximately 15 Gy. 10 refs., 4 figs., 1 tab

  1. Novel Scanning Lens Instrument for Evaluating Fresnel Lens Performance: Equipment Development and Initial Results (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Herrero, R.; Miller, D. C.; Kurtz, S. R.; Anton, I.; Sala, G.

    2013-07-01

    A system dedicated to the optical transmittance characterization of Fresnel lenses has been developed at NREL, in collaboration with the UPM. The system quantifies the optical efficiency of the lens by generating a performance map. The shape of the focused spot may also be analyzed to understand change in the lens performance. The primary instrument components (lasers and CCD detector) have been characterized to confirm their capability for performing optical transmittance measurements. Measurements performed on SoG and PMMA lenses subject to a variety of indoor conditions (e.g., UV and damp heat) identified differences in the optical efficiency of the evaluated lenses, demonstrating the ability of the Scanning Lens Instrument (SLI) to distinguish between the aged lenses.

  2. Pharmacogenomics of warfarin: uncovering a piece of the warfarin mystery.

    Science.gov (United States)

    Gulseth, Michael P; Grice, Gloria R; Dager, William E

    2009-01-15

    The literature on the pharmacogenomics of warfarin and the use of genetic testing to optimize initial and maintenance warfarin dosing is reviewed. Warfarin tablets contain a racemic mixture of R- and S-isomers. The S-isomer is responsible for about 70% of warfarin's anticoagulant effect. Cytochrome P-450 isoenzyme 2C9 (CYP2C9) metabolizes S-warfarin into two inactive metabolites. Genetic variations to the gene encoding CYP2C9 (CYP2C9 ) are known to affect warfarin clearance. Single nucleotide polymorphisms (SNPs) have been identified that clearly influence warfarin metabolism and sensitivity, including SNP variants of CYP2C9 and SNPs in vitamin K epoxide reductase complex subunit 1 (VKORC1), which influence an individual's sensitivity to a given dose. Retrospective studies have evaluated potential factors influencing warfarin metabolism, maintenance dosing, and variability. Several dosing models used to predict warfarin dosing (initial or refinement) have been retrospectively evaluated in diverse patient populations. There are several arguments to support incorporating its use in current clinical practice; however, many expert clinicians in anticoagulation have expressed concern that the push for genotyping patients for CYP2C9 and VKORC1 is premature and not based on good, prospective evidence. Large, randomized controlled trials, in multiple patient populations, comparing clinical dosing to genetic-guided dosing are needed to fully determine the benefits of pharmacogenetic warfarin dosing. The increased understanding of pharmacogenomics may improve patient safety during initial dosing of warfarin. At this time, it is unknown if genotype-based dosing will become the standard of care for patients receiving the drug.

  3. Contact lens-related microbial keratitis: how have epidemiology and genetics helped us with pathogenesis and prophylaxis

    Science.gov (United States)

    Stapleton, F; Carnt, N

    2012-01-01

    Contact lens wear is a common predisposing factor in microbial keratitis and is one of the two preventable risk factors for corneal infection in a working age population. Our understanding of the prevention and prophylaxis of contact lens-related corneal infection is informed by recent epidemiological studies describing the incidence of and risk factors for the disease, the effect of causative organism on disease severity, and an appreciation of individual immune profiles in susceptibility to and severity of the disease. Although contemporary contact lenses have not reduced the overall incidence of keratitis, a reduction in morbidity may be achievable through recognition of appropriate risk factors in severe disease, including avoiding delays in presenting for appropriate treatment, and attention to storage case hygiene practise. Severe keratitis is most commonly associated with an environmental causative organism, and daily disposable lenses are associated with less severe disease. Pseudomonas aeruginosa remains the commonest cause of contact lens-related corneal infection probably because of its unique virulence characteristics and ability to survive in the contact lens/storage case/ocular environment. In two recent outbreaks of contact lens-related infections, there has been a strong association demonstrated with particular contact lens solutions. Since the recall of these specific contact lens solutions, the rate of Acanthamoeba keratitis has remained above the expected baseline, indicating unidentified risk factors that may include environmental exposures. Individual differences in susceptibility to microbial keratitis may be partly explained by differences in single-nucleotide polymorphisms in certain cytokine genes, particularly those with a proven protective role in corneal infection. PMID:22134592

  4. A Strong-Lens Survey in AEGIS: the influence of large scalestructure

    Energy Technology Data Exchange (ETDEWEB)

    Moustakas, Leonidas A.; Marshall, Phil; Newman, Jeffrey A.; Coil,Alison L.; Cooper, Michael C.; Davis, Marc; Fassnacht, Christopher D.; Guhathakurta, Puragra; Hopkins, Andrew; Koekemoer, Anton; Konidaris,Nicholas P.; Lotz, Jennifer M.; Willmer, Christopher N. A.

    2006-10-13

    We report on the results of a visual search for galaxy-scale strong gravitational lenses over 650 arcmin{sup 2} of HST/ACS (F606W and F814W) imaging in the DEEP2-Extended Groth Strip (EGS). In addition to a previously-known Einstein Cross also found by our search (the 'Cross', HSTJ141735+52264, z{sub lens} = 0.8106, z{sub source} = 3.40), we identify two new strong galaxy-galaxy lenses with multiple extended arcs. The first, HSTJ141820+52361 (the 'Dewdrop'; z{sub lens} = 0.5798), lenses two distinct extended sources into two pairs of arcs (z{sub source} = 0.9818), while the second, HSTJ141833+52435 (the 'Anchor'; z{sub lens} = 0.4625), produces a single pair of arcs (z{sub lens} not yet known). Four less convincing arc/counter-arc and two-image lens candidates are also found and presented for completeness. Lenses are found in a both underdense and overdense local environments, as characterized by a robust measure, 1+{delta}{sub 3}, a normalized density that uses the distance to the third nearest neighbor. All three definite lenses are fit reasonably well by simple singular isothermal ellipsoid models including external shear, giving {chi}{sub {nu}}{sup 2} values close to unity. These shears are much greater than those implied by a simple consideration of the three-dimensional convergence and shear from galaxies along the line of sight, where each galaxy is approximated by a singular isothermal sphere halo truncated at 200 h{sup -1} kpc. This shows how a realistic treatment of galaxies and the large scale structure they are embedded in is necessary, and that simply characterizing the very-local environment may be insufficient.

  5. Optical design of transmitter lens for asymmetric distributed free space optical networks

    Science.gov (United States)

    Wojtanowski, Jacek; Traczyk, Maciej

    2018-05-01

    We present a method of transmitter lens design dedicated for light distribution shaping on a curved and asymmetric target. In this context, target is understood as a surface determined by hypothetical optical detectors locations. In the proposed method, ribbon-like surfaces of arbitrary shape are considered. The designed lens has the task to transform collimated and generally non-uniform input beam into desired irradiance distribution on such irregular targets. Desired irradiance is associated with space-dependant efficiency of power flow between the source and receivers distributed on the target surface. This unconventional nonimaging task is different from most illumination or beam shaping objectives, where constant or prescribed irradiance has to be produced on a flat target screen. The discussed optical challenge comes from the applications where single transmitter cooperates with multitude of receivers located in various positions in space and oriented in various directions. The proposed approach is not limited to optical networks, but can be applied in a variety of other applications where nonconventional irradiance distribution has to be engineered. The described method of lens design is based on geometrical optics, radiometry and ray mapping philosophy. Rays are processed as a vector field, each of them carrying a certain amount of power. Having the target surface shape and orientation of receivers distribution, the rays-surface crossings map is calculated. It corresponds to the output rays vector field, which is referred to the calculated input rays spatial distribution on the designed optical surface. The application of Snell's law in a vector form allows one to obtain surface local normal vector and calculate lens profile. In the paper, we also present the case study dealing with exemplary optical network. The designed freeform lens is implemented in commercially available optical design software and irradiance three-dimensional spatial distribution is

  6. Inspection of complex geometry pieces with an intelligent contact transducer; Inspection de pieces de geometrie complexe a l'aide d'un traducteur contact intelligent

    Energy Technology Data Exchange (ETDEWEB)

    Chatillon, S.; Roy, O.; Mahaut, St

    2000-07-01

    A new multi-element contact transducer has been developed to improve the inspection of components with complex geometry. The emitting surface is flexible in order to optimize the contact with pieces. An algorithm, based on a simplified geometric model, has been used to determine the delays law which allows to control the focal characteristics of the transmitted field. Acquisition data lead in transmission with an articulated transducer validate the behavior provided by simulation. Thus the optimization of the delays law ensures the transmission of a beam which is homogeneous and controlled during the moving of the transducer. Inspections in echo-pulse mode are implemented on a sample simulating a component controlled on site. Results show that the dynamical adaptation of the delays law to the geometry of the piece leads to very good performances.

  7. The neutron silicon lens. An update of the thermal neutron lens results

    International Nuclear Information System (INIS)

    Johnson, M.W.; Daymond, M.R.

    2001-01-01

    This paper introduces the concept of the Neutron Silicon Lens (NSL) and provides and update on the experimental results achieved to date. The NSL design is a cylindrical neutron lens based on the use of multiple neutron mirrors supported and separated by silicon wafers. Such lenses would have many applications in both the primary and scattered beams on neutron instruments, and would lead to immediate improvements where the sample to be illuminated is small, as in high pressure or engineering strain scanning instruments. (author)

  8. Small DNA pieces in C. elegans are intermediates of DNA fragmentation during apoptosis.

    Directory of Open Access Journals (Sweden)

    P Joseph Aruscavage

    2010-06-01

    Full Text Available While studying small noncoding RNA in C. elegans, we discovered that protocols used for isolation of RNA are contaminated with small DNA pieces. After electrophoresis on a denaturing gel, the DNA fragments appear as a ladder of bands, approximately 10 nucleotides apart, mimicking the pattern of nuclease digestion of DNA wrapped around a nucleosome. Here we show that the small DNA pieces are products of the DNA fragmentation that occurs during apoptosis, and correspondingly, are absent in mutant strains incapable of apoptosis. In contrast, the small DNA pieces are present in strains defective for the engulfment process of apoptosis, suggesting they are produced in the dying cell prior to engulfment. While the small DNA pieces are also present in a number of strains with mutations in predicted nucleases, they are undetectable in strains containing mutations in nuc-1, which encodes a DNase II endonuclease. We find that the small DNA pieces can be labeled with terminal deoxynucleotidyltransferase only after phosphatase treatment, as expected if they are products of DNase II cleavage, which generates a 3' phosphate. Our studies reveal a previously unknown intermediate in the process of apoptotic DNA fragmentation and thus bring us closer to defining this important pathway.

  9. Numerical simulation of water flow through the bottom end piece of a nuclear fuel assembly

    International Nuclear Information System (INIS)

    Navarro, Moyses Alberto; Santos, Andre A.C. dos

    2007-01-01

    An experimental and numerical study was conducted on the pressure loss of flows through the bottom end piece of a nuclear fuel assembly. To determine an optimized numerical methodology using the commercial CFD code, CFX 10.0, a series of preliminary simulations of water flows through perforated plates in a square ducts were performed. A perforated plate is a predominant geometry of the bottom end piece, responsible for the majority of the flow's pressure drop. The numerical pressure loss applying an optimized mesh and the k-ε turbulence model showed good agreement when compared with a conventional methodology (Idelchik). Numerical results for the standard bottom end piece were obtained applying the previously determined mesh criteria and the k-ε turbulence model with some geometric simplifications. The agreement between the numerical simulations and experimental results can be considered satisfactory but suggest further numerical investigations with the bottom piece under real conditions of the experiment, without the geometric simplifications and with a gap between the piece and the wall of the flow channel. Additionally, other turbulence models should be appraised for this complex geometry. (author)

  10. Numerical Simulation of Water Flow through the Bottom End Piece of a Nuclear Fuel Assembly

    Science.gov (United States)

    Navarro, Moysés A.; Santos, André A. C. Dos

    An experimental and numerical study was conducted on the pressure loss of flows through the bottom end piece of a nuclear fuel assembly. To determine an optimized numerical methodology using the commercial CFD code, CFX 10.0, a series of preliminary simulations of water flows through perforated plates in a square ducts were performed. A perforated plate is a predominant geometry of the bottom end piece, responsible for the majority of the flow's pressure drop. The numerical pressure loss applying an optimized mesh and the k-ɛ turbulence model showed good agreement when compared with a conventional methodology (Idelchik). Numerical results for the standard bottom end piece were obtained applying the previously determined mesh criteria and the k-ɛ turbulence model with some geometric simplifications. The agreement between the numerical simulations and experimental results can be considered satisfactory but suggests further numerical investigations with the bottom piece under real conditions of the experiment, without the geometric simplifications and with a gap between the piece and the wall of the flow channel. Additionally, other turbulence models should be appraised for this complex geometry.

  11. Lens regeneration in mice under the influence of vitamin A

    Indian Academy of Sciences (India)

    The effect of vitamin A has been studied on lens regeneration in young (7 days old) as well as adult mice. A longitudinal slit was made under local anesthesia in the cornea over the lens. The lens was extracted intact through the incision. Intraperitonial injection of vitamin A (0.05 ml of 30 IU/ml in young and 0.05 ml of 50 ...

  12. Subcontact Lens Bubble Formation under Low Atmospheric Pressure Conditions.

    Science.gov (United States)

    1986-08-01

    of subcontact lens bubble formation under scleral lenses at altitudes greater than 18,000 ft. Later, after many advances in contact lens fitting and...Reported here are the results of contact lens bubble studies with soft hydrophilic nd rigid gas-permeable lenses . Testing was accomplished in simulated...ccurred at altitudes greater than 20,000 ft. For soft contact lenses , bubble formation was etected in 22 of 92 eyes tested, and occurred at altitudes

  13. Analysis of phakic before intraocular lens implantation for fundus examination

    OpenAIRE

    Juan Chen; Zhong-Ping Chen; Rui-Ling Zhu

    2014-01-01

    AIM:To investigate the findings of the eyes which were examined preoperatively by three mirror contact lens before the implantation of implantable collamer lens(ICL). To analysis the retinal pathological changes and to explore the clinical analysis of early diagnosis and treatment in retinopathy on fundus examination before operation. METHODS:The retrospective case series study included 127 eyes of 64 patients who underwent phakic intraocular lens implantation were received the fundus examina...

  14. Haemophilus influenzae corneal ulcer in a therapeutic contact lens wearer.

    OpenAIRE

    Armstrong, J. R.; Cohen, K. L.; McCarthy, L. R.

    1984-01-01

    Haemophilus influenzae is an unusual corneal pathogen and an unusual cause of corneal ulcers in Western society. In previous reports corneal complications from H. influenzae have been secondary to a conjunctivitis. The first case of a primary H. influenzae corneal ulcer as a complication of therapeutic contact lens wear is presented. Since other uncommon bacteria have been reported as causes of contact lens related corneal ulcers, the bacteriology of contact lens related corneal ulcers is rev...

  15. Java Application Shell: A Framework for Piecing Together Java Applications

    Science.gov (United States)

    Miller, Philip; Powers, Edward I. (Technical Monitor)

    2001-01-01

    This session describes the architecture of Java Application Shell (JAS), a Swing-based framework for developing interactive Java applications. Java Application Shell is being developed by Commerce One, Inc. for NASA Goddard Space Flight Center Code 588. The purpose of JAS is to provide a framework for the development of Java applications, providing features that enable the development process to be more efficient, consistent and flexible. Fundamentally, JAS is based upon an architecture where an application is considered a collection of 'plugins'. In turn, a plug-in is a collection of Swing actions defined using XML and packaged in a jar file. Plug-ins may be local to the host platform or remotely-accessible through HTTP. Local and remote plugins are automatically discovered by JAS upon application startup; plugins may also be loaded dynamically without having to re-start the application. Using Extensible Markup Language (XML) to define actions, as opposed to hardcoding them in application logic, allows easier customization of application-specific operations by separating application logic from presentation. Through XML, a developer defines an action that may appear on any number of menus, toolbars, and buttons. Actions maintain and propagate enable/disable states and specify icons, tool-tips, titles, etc. Furthermore, JAS allows actions to be implemented using various scripting languages through the use of IBM's Bean Scripting Framework. Scripted action implementation is seamless to the end-user. In addition to action implementation, scripts may be used for application and unit-level testing. In the case of application-level testing, JAS has hooks to assist a script in simulating end-user input. JAS also provides property and user preference management, JavaHelp, Undo/Redo, Multi-Document Interface, Single-Document Interface, printing, and logging. Finally, Jini technology has also been included into the framework by means of a Jini services browser and the

  16. Design and Tests of a High-Performance Long-Wave Infrared Refractive Thermal Imager: Freeform Lens in Coaxial System

    Directory of Open Access Journals (Sweden)

    Jinjin Chen

    2017-11-01

    Full Text Available In this paper, we used a freeform lens in a long-wave, un-cooled, refractive infrared (IR thermal imager and present the design strategy and test results. This optical system is composed of only one freeform lens and several spheres. It can correct the distortion issue inherent to wide field-of-view systems more effectively, and achieve a better thermal imaging performance simultaneously compared to traditional aspheric optical lenses. Such a design model can alleviate the calculation load and cater for the demand of the ultra-precision turning on single crystal germanium. It satisfies the design idea of freeform surfaces with machining feasibility. The refractive freeform IR imager can be realized from the theoretical design to the engineering applications. The research contents of this paper are helpful for the further application of the freeform lens to a more complex cooled infrared refractive thermal imager.

  17. In-the-bag capsular tension ring and intraocular lens subluxation or dislocation: a series of 23 cases.

    Science.gov (United States)

    Werner, Liliana; Zaugg, Brian; Neuhann, Tobias; Burrow, Michael; Tetz, Manfred

    2012-02-01

    To describe clinical and pathologic findings from cases of in-the-bag capsular tension ring (CTR) and intraocular lens (IOL) subluxation or dislocation. Retrospective case series with clinicopathologic correlation. Twenty-three explanted subluxated/dislocated capsular bags containing a CTR and an IOL explanted in Europe and submitted in fixative to the Berlin Eye Research Institute. Standard gross and light microscopy of specimens, complete histopathologic analyses of selected specimens done at the University of Utah, as well as questionnaire sent to explanting surgeons, and patient chart review, when available. Lens design, material, and abnormalities, capsular bag anomalies, patient demographic data, surgical dates, and presence or absence of known risk factors. Patients were aged 76.31 ± 8.24 years at explantation, which was performed 81.5 ± 32.2 months after implantation. The IOLs in these cases were 3-piece hydrophobic acrylic (N = 11), 1-piece hydrophobic acrylic (n = 6), 3-piece silicone (n = 4), or 1-piece hydrophilic acrylic (n = 2) designs; all CTRs were made of poly(methyl methacrylate). Available information on associated ocular conditions included pseudoexfoliation (n = 17), glaucoma (n = 4), vitrectomy/retina surgery (n = 3), and trauma (n = 1). Complete histopathologic assessment in 3 specimens showed signs consistent with pseudoexfoliation, without available history related to this condition in one of the cases. Moderate/severe degrees of Soemmering's ring formation and capsulorhexis phimosis were observed or reported in 13 and 11 specimens, respectively. Fourteen eyes were implanted and explanted by the same surgeon, with an interval of 92.7 ± 23.4 months between the procedures. His rate of explantation because of subluxation/dislocation was 0.76% of the CTRs implanted during the time considered. Explantation because of postoperative subluxation or dislocation of CTR-IOL-capsular bag complexes occurred approximately 6.8 years after implantation

  18. Disposable contact lenses vs. contact lens maintenance for extended wear.

    Science.gov (United States)

    Josephson, J E; Caffery, B E; Campbell, I; Slomovic, A R

    1990-01-01

    We compared a disposable extended wear contact lens modality with conventional extended wear over a 6-week period. To do so, we refit 31 patients who had successfully worn conventional extended wear contact lenses for more than 1 year. One eye was fit with the AcuvueR disposable contact lens, and a new extended wear lens of the type the patient had been wearing was placed on the other eye. At weekly intervals the disposable lens was discarded and a new disposable lens inserted. At the same time, the conventional lens on the fellow eye was cleaned, disinfected, and reinserted. After 6 weeks the ocular response, subjective impressions, and condition of the lenses in the two eyes were compared. Both lenses were then cultured. Three subjects had to discontinue disposable lens wear because of adverse reactions to trapped cellular debris and corneal microcysts. Although the results were not statistically significant, the Acuvue lens appeared to perform better than or equal to the conventional lens in biomicroscopic observation, visual acuity measurement, and subjective patient preference. Eighty-seven percent of patients preferred to continue with the disposable system. There were no differences found in the type or degree of microbial contamination of the lenses.

  19. Further studies of contact lens motion during blinking.

    Science.gov (United States)

    Conway, H D; Knoll, H A

    1986-10-01

    Contact lens motion is felt to be of increasing importance in connection with debris elimination, particularly in extended wear lenses. Thus an improved analysis is made of a simple model for investigating the initial motion of a hard contact lens over the eye during blinking. It is shown that the assumption of constant tear film thickness is a reasonable one. This greatly simplifies the analysis. Various vertical force vs. time variations are considered and lens velocity/time graphs and maximum lens displacement calculated. These are in good agreement with the results of experiment.

  20. Geometry-invariant gradient refractive index lens: analytical ray tracing.

    Science.gov (United States)

    Bahrami, Mehdi; Goncharov, Alexander V

    2012-05-01

    A new class of gradient refractive index (GRIN) lens is introduced and analyzed. The interior iso-indicial contours mimic the external shape of the lens, which leads to an invariant geometry of the GRIN structure. The lens model employs a conventional surface representation using a coincoid of revolution with a higher-order aspheric term. This model has a unique feature, namely, it allows analytical paraxial ray tracing. The height and the angle of an arbitrary incident ray can be found inside the lens in a closed-form expression, which is used to calculate the main optical characteristics of the lens, including the optical power and third-order monochromatic aberration coefficients. Moreover, due to strong coupling of the external surface shape to the GRIN structure, the proposed GRIN lens is well suited for studying accommodation mechanism in the eye. To show the power of the model, several examples are given emphasizing the usefulness of the analytical solution. The presented geometry-invariant GRIN lens can be used for modeling and reconstructing the crystalline lens of the human eye and other types of eyes featuring a GRIN lens.

  1. Particle swarm optimization applied to automatic lens design

    Science.gov (United States)

    Qin, Hua

    2011-06-01

    This paper describes a novel application of Particle Swarm Optimization (PSO) technique to lens design. A mathematical model is constructed, and merit functions in an optical system are employed as fitness functions, which combined radiuses of curvature, thicknesses among lens surfaces and refractive indices regarding an optical system. By using this function, the aberration correction is carried out. A design example using PSO is given. Results show that PSO as optical design tools is practical and powerful, and this method is no longer dependent on the lens initial structure and can arbitrarily create search ranges of structural parameters of a lens system, which is an important step towards automatic design with artificial intelligence.

  2. [Phacoemulsification of subluxated lens with capsular tension ring implantation].

    Science.gov (United States)

    Dorecka, Mariola; Rokicki, Wojciech; Nita, Malgorzata; Krysik, Katarzyna; Nita, Ewa; Sikorska, Aleksandra; Romaniuk, Wanda

    2007-01-01

    To evaluate long term results of phacoemulsification with PC IOL and capsular tension ring (CTR) implantation in lens subluxation. The study comprised of 134 patients--146 eyes with subluxated lens. In all cases phacoemulsification with PC IOL and CTR implantation was performed. No intaroperative complications has occured. Postoperative complications included: inflammation in the anterior chamber in 3 eyes (2.1%), retinal detachment in 2 eyes (1.4%). In all cases there was no PC IOL decentration. (1) CTR facilitates phacoemulsification with PC IOL implantation in lens subluxation. (2) Phacoemulsification of subluxated lens with PC IOL and CTR implantation seems to be safe and effective procedure.

  3. Acoustic Luneburg lens using orifice-type metamaterial unit cells

    Science.gov (United States)

    Park, Choon Mahn; Lee, Sang Hun

    2018-02-01

    A two-dimensional acoustic Luneburg lens that can be easily expanded into a three-dimensional sphere is fabricated. The required spatial distribution of the refractive index for this Luneburg lens is realized using the characteristics of orifice-type metamaterial unit cells. Typical characteristics of the resulting acoustic Luneburg lens, such as its aberration-free performance and capability for antipodal focusing of the lens for the incident plane waves, are investigated through experiments and simulations with the attenuation loss at frequencies that satisfy the homogeneous medium condition of the metamaterial. With the designed metamaterial, we achieved the minimum spot that lies within the classical diffraction limit at the focal point.

  4. Design of TIR collimating lens for ordinary differential equation of extended light source

    Science.gov (United States)

    Zhan, Qianjing; Liu, Xiaoqin; Hou, Zaihong; Wu, Yi

    2017-10-01

    The source of LED has been widely used in our daily life. The intensity angle distribution of single LED is lambert distribution, which does not satisfy the requirement of people. Therefore, we need to distribute light and change the LED's intensity angle distribution. The most commonly method to change its intensity angle distribution is the free surface. Generally, using ordinary differential equations to calculate free surface can only be applied in a point source, but it will lead to a big error for the expand light. This paper proposes a LED collimating lens based on the ordinary differential equation, combined with the LED's light distribution curve, and adopt the method of calculating the center gravity of the extended light to get the normal vector. According to the law of Snell, the ordinary differential equations are constructed. Using the runge-kutta method for solution of ordinary differential equation solution, the curve point coordinates are gotten. Meanwhile, the edge point data of lens are imported into the optical simulation software TracePro. Based on 1mm×1mm single lambert body for light conditions, The degrees of collimating light can be close to +/-3. Furthermore, the energy utilization rate is higher than 85%. In this paper, the point light source is used to calculate partial differential equation method and compared with the simulation of the lens, which improve the effect of 1 degree of collimation.

  5. Focal length estimation guided with object distribution on FocaLens dataset

    Science.gov (United States)

    Yan, Han; Zhang, Yu; Zhang, Shunli; Zhao, Sicong; Zhang, Li

    2017-05-01

    The focal length information of an image is indispensable for many computer vision tasks. In general, focal length can be obtained via camera calibration using specific planner patterns. However, for images taken by an unknown device, focal length can only be estimated based on the image itself. Currently, most of the single-image focal length estimation methods make use of predefined geometric cues (such as vanishing points or parallel lines) to infer focal length, which constrains their applications mainly on manmade scenes. The machine learning algorithms have demonstrated great performance in many computer vision tasks, but these methods are seldom used in the focal length estimation task, partially due to the shortage of labeled images for training the model. To bridge this gap, we first introduce a large-scale dataset FocaLens, which is especially designed for single-image focal length estimation. Taking advantage of the FocaLens dataset, we also propose a new focal length estimation model, which exploits the multiscale detection architecture to encode object distributions in images to assist focal length estimation. Additionally, an online focal transformation approach is proposed to further promote the model's generalization ability. Experimental results demonstrate that the proposed model trained on FocaLens can not only achieve state-of-the-art results on the scenes with distinct geometric cues but also obtain comparable results on the scenes even without distinct geometric cues.

  6. Spontaneous dislocation of lens bag with acrylic lens after uneventful cataract surgery ? unusual complication of cataract surgery

    OpenAIRE

    Shah, Mehul A.; Shah, Shreya M.; Mehta, Ruchir; Shah, Prerna

    2015-01-01

    Introduction: Spontaneous dislocation of intraocular lens with bag is rare.Methods: We report a case of a 56-year-old male who presented with spontaneous anterior dislocation of an in-the-bag intraocular lens 3 years after manual small incision cataract surgery. He had undergone manual small incision cataract surgery with foldable acrylic intraocular lens implantation, and 18 months after cataract surgery ND: YAG capsulotomy with uneventful post capsulotomy follow-up. 17 months after capsul...

  7. LENS - the Low-Energy Neutrino Spectrometer

    International Nuclear Information System (INIS)

    Hahn, Richard L.

    2004-01-01

    Despite the recent successes of SNO and KamLAND, the only detectors sensitive to <1 MeV-neutrinos have been the radiochemical chlorine and gallium solar neutrino experiments. LENS is being developed to measure in real time the charge-current fluxes and energy spectra of the lowest energy solar neutrinos, from the pp and 7Be branches (91% and 7% of solar neutrinos). The detector medium will be a metal-loaded liquid scintillator (M-LS), with indium as the metal, which serves as the target for neutrino capture in the LS. 115In has 95.71% natural abundance and a 114.2-keV neutrino-capture Q-value. Neutrino capture in 115In produces a β particle and preferentially feeds an excited state of 115Sn that de-excites by delayed emission of two γ rays. This triple-coincidence 'tag' in time and space in principle is a very powerful tool to discriminate neutrino-capture events from backgrounds. The International LENS R and D Collaboration is working to develop an In-LS neutrino detector, with special properties, such as high indium content, high light yield, high optical transparency, long-term chemical stability, and good signal-to-background ratio. Success in preparing the In-LS has been achieved via the synthesis of In-carboxylates that are soluble in pseudocumene LS (note that these methods may also be applicable to the preparation of Gd-LS for reactor antineutrino experiments). Testing of some prototype LENS In-LS detector modules has begun recently at the Gran Sasso Laboratory

  8. [Corneal protection in contact lens users].

    Science.gov (United States)

    Egorova, G B; Mitichkina, T S; Shamsudinova, A R

    2014-01-01

    To evaluate the efficacy of corneoprotective agents (Corneregel and Solcoseryl) in contact lens users. A total of 66 long-term contact lens wearers with dry eye symptoms and varying degrees of corneal epitheliopathy were monitored. All patients used artificial tears, which, however, were not effective enough to suppress manifestations of corneal epitheliopathy and to release the associated discomfort. The therapy was supplemented with Corneregel. The following examination methods were applied: biomicroscopy with fluorescent staining, Norn test, Schirmer's test, advanced tearscopy with digital image analysis of the precorneal tear film lipid layer, corneal confocal microscopy. In all cases the assessment was performed prior to starting Corneregel and repeated in 7 days, 14 days and 1 month. Complete corneal re-epithelization and restoration of the most superficial layer of the epithelium were achieved within 7-14 days. In case of severe initial epitheliopathy the effect of Corneregel was not sufficient and epithelium defects remained. These patients additionally received Solcoseryl Eye Gel. After the treatment course the condition of corneal epithelium ameliorated and contact lens wearing comfort increased. A longer precorneal tear film break-up time indicated an increase of tear film stability. The total tear production did not change significantly. The moistening effect of Corneregel and low-viscosity artificial tears together with intensive regeneration of corneal epithelium enables structural recovery of the epithelial membrane and considerable improvement of the anterior corneal stroma. At the first stage of corneoprotective treatment it is appropriate to use preservative-free artificial tears of low and high viscosity. If the effect of tear substitutive therapy is unsatisfactory it is recommended to prescribe Corneregel and Solcoseryl. The regimen is to be adjusted individually.

  9. Fabrication par injection flexible de pieces coniques pour des applications aerospatiales

    Science.gov (United States)

    Shebib Loiselle, Vincent

    Les materiaux composites sont presents dans les tuyeres de moteurs spatiaux depuis les annees soixante. Aujourd'hui, l'avenement des tissus tridimensionnels apporte une solution innovatrice au probleme de delamination qui limitait les proprietes mecaniques de ces composites. L'utilisation de ces tissus necessite toutefois la conception de procedes de fabrication mieux adaptes. Une nouvelle methode de fabrication de pieces composites pour des applications aerospatiales a ete etudiee tout au long de ce travail. Celle-ci applique les principes de l'injection flexible (procede Polyflex) a la fabrication de pieces coniques de fortes epaisseurs. La piece de validation a fabriquer represente un modele reduit de piece de tuyere de moteur spatial. Elle est composee d'un renfort tridimensionnel en fibres de carbone et d'une resine phenolique. La reussite du projet est definie par plusieurs criteres sur la compaction et la formation de plis du renfort et sur la formation de porosites de la piece fabriquee. Un grand nombre d'etapes ont ete necessaires avant la fabrication de deux pieces de validation. Premierement, pour repondre au critere sur la compaction du renfort, la conception d'un outil de caracterisation a ete entreprise. L'etude de la compaction a ete effectuee afin d'obtenir les informations necessaires a la comprehension de la deformation d'un renfort 3D axisymetrique. Ensuite, le principe d'injection de la piece a ete defini pour ce nouveau procede. Pour en valider les concepts proposes, la permeabilite du renfort fibreux ainsi que la viscosite de la resine ont du etre caracterisees. A l'aide de ces donnees, une serie de simulations de l'ecoulement pendant l'injection de la piece ont ete realisees et une approximation du temps de remplissage calculee. Apres cette etape, la conception du moule de tuyere a ete entamee et appuyee par une simulation mecanique de la resistance aux conditions de fabrication. Egalement, plusieurs outillages necessaires pour la fabrication

  10. Performance-Based Design Optimization of a Transition Piece for Bucket Foundations for Offshore Wind Turbines

    DEFF Research Database (Denmark)

    Nezhentseva, Anastasia; Andersen, Lars; Ibsen, Lars Bo

    2011-01-01

    This paper deals with optimization of the shape of the transition piece connecting turbine column with a suction bucket used as a monopod foundation for an offshore wind turbine. The structural behaviour of a transition piece made of compact reinforced composite (CRC) is analysed. Several...... geometries are compared to find the one providing better force distribution, preventing stress concentration and buckling, reducing the amount of material used as well as potentially minimizing scour. Local optimization of the cross section is performed with the aim of minimizing the material consumption...... (steel, as well as CRC). A non-linear finiteelement model is developed for analysis of the structure....

  11. Lentil (Lens culinaris) Lipid Transfer Protein Len c 3: A Novel Legume Allergen

    NARCIS (Netherlands)

    Akkerdaas, J.; Finkina, E. I.; Balandin, S. V.; Santos Magadán, S.; Knulst, A.; Fernandez-Rivas, M.; Asero, R.; van Ree, R.; Ovchinnikova, T. V.

    2012-01-01

    Background: Lentils are increasingly consumed in many parts of the world. Two allergens, Len c 1 and 2, have been reported previously. Recently, peanut and green bean lipid transfer proteins (LTPs) have been identified as the first two members of an important group of allergens that might be

  12. Abnormal lens morphogenesis and ectopic lens formation in the absence of beta-catenin function

    Czech Academy of Sciences Publication Activity Database

    Krešlová, Jana; Machoň, Ondřej; Růžičková, Jana; Láchová, Jitka; Wawrousek, E.F.; Kemler, R.; Krauss, S.; Piatigorsky, J.; Kozmik, Zbyněk

    2007-01-01

    Roč. 45, č. 4 (2007), s. 157-168 ISSN 1526-954X R&D Projects: GA ČR GA204/04/1358 Institutional research plan: CEZ:AV0Z50520514 Keywords : Wnt * beta-catenin * gene * lens Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.516, year: 2007

  13. Antenna and coil design for wireless signal detection and charging of embedded power active contact lens.

    Science.gov (United States)

    Ng, Benny; Heckler, Paul; Do, Alex; Azar, Phillip; Leon, Errol; Smilkstein, Tina

    2014-01-01

    This paper presents a screen printed 2.4 GHz antenna and induction charging coil for an active contact lens with a single large pixel user display and on-board 3.8 V 5 uAh rechargeable battery. The antenna traces are printed using silver conductive paste on a 25 um polyethylene terephthalate (PET) substrate. The incoming signal from the antenna feeds into an IC that amplifies and rectifies the signal. The coil provides wireless energy transfer to inductively charge a thin film battery [1] located on the contact lens. The printed antenna achieved a S11 of -4 dB at 2.4 GHz and a gain of -13 dB.

  14. Evolution of a protein superfamily: relationships between vertebrate lens crystallins and microorganism dormancy proteins.

    Science.gov (United States)

    Wistow, G

    1990-02-01

    A search of sequence databases shows that spherulin 3a, an encystment-specific protein of Physarum polycephalum, is probably structurally related to the beta- and gamma-crystallins, vertebrate ocular lens proteins, and to Protein S, a sporulation-specific protein of Myxococcus xanthus. The beta- and gamma-crystallins have two similar domains thought to have arisen by two successive gene duplication and fusion events. Molecular modeling confirms that spherulin 3a has all the characteristics required to adopt the tertiary structure of a single gamma-crystallin domain. The structure of spherulin 3a thus illustrates an earlier stage in the evolution of this protein superfamily. The relationship of beta- and gamma-crystallins to spherulin 3a and Protein S suggests that the lens proteins were derived from an ancestor with a role in stress-response, perhaps a response to osmotic stress.

  15. Pars plana vitrectomy with posterior iris claw implantation for posteriorly dislocated nucleus and intraocular lens

    Directory of Open Access Journals (Sweden)

    Kishor B Patil

    2011-01-01

    Full Text Available We evaluated the safety and efficacy of pars plana vitrectomy (PPV with primary posterior iris claw intraocular lens (IOL implantation in cases of posterior dislocation of nucleus and IOL without capsular support. This was a retrospective interventional case series. Fifteen eyes underwent PPV with primary posterior iris claw IOL implantation performed by a single vitreoretinal surgeon. The main outcome measures were changes in best corrected visual acuity and anterior and posterior segment complications. A total of 15 eyes were included in this study. Eight had nucleus drop, three had IOL drop during cataract surgery and four had traumatic posterior dislocation of lens. The final postoperative best corrected visual acuity was 20/60 or better in 11 patients. This procedure is a viable option in achieving good functional visual acuity in eyes without capsular support.

  16. Statistical simplex approach to primary and secondary color correction in thick lens assemblies

    Science.gov (United States)

    Ament, Shelby D. V.; Pfisterer, Richard

    2017-11-01

    A glass selection optimization algorithm is developed for primary and secondary color correction in thick lens systems. The approach is based on the downhill simplex method, and requires manipulation of the surface color equations to obtain a single glass-dependent parameter for each lens element. Linear correlation is used to relate this parameter to all other glass-dependent variables. The algorithm provides a statistical distribution of Abbe numbers for each element in the system. Examples of several lenses, from 2-element to 6-element systems, are performed to verify this approach. The optimization algorithm proposed is capable of finding glass solutions with high color correction without requiring an exhaustive search of the glass catalog.

  17. Survival Rates and Bone and Soft Tissue Level Changes Around One-Piece Dental Implants Placed with a Flapless or Flap Protocol: 8.5-Year Results.

    Science.gov (United States)

    Froum, Stuart J; Khouly, Ismael

    The purpose of the current study was to determine the survival rates and to measure marginal bone changes and peri-implant conditions 8.5 years after placement of one-piece implants with an anodically oxidized surface (AOS). A total of 52 subjects who received a one-piece implant with an AOS using a flapless or flap protocol and completed a previous randomized clinical trial were contacted for a recall visit 8.5 years after implant placement (T 8.5 ). Implant success and survival rates, probing pocket depth (PPD), presence of bleeding on probing (BoP), papilla level, and incidence of complications and peri-implant disease were assessed by a single, blinded examiner. A second blinded examiner evaluated marginal bone level changes. Results for 8.5 years were compared to those at the time of implant placement, implant loading (0.5 year), and 1 and 1.5 years follow-up. The results based on 28 patients who attended the follow-up visit (half had flapless and half a flap protocol) showed a 100% implant survival rate and a 96.4% implant success rate 8.5 years after implant placement using one-piece implants, with no difference in survival and success rates between the flapless and the flap protocol. During the same follow-up period, a significant increase in crestal bone height from 1.5 to 8.5 years was observed. Analysis suggested decreasing mean levels of bone loss with time (P One-piece implants with an AOS showed high survival rates and stable marginal bone and periimplant soft tissue levels regardless of whether a flapless or flap protocol was used.

  18. Magnetic system of the Tevatron electron lens

    International Nuclear Information System (INIS)

    Bogdanov, I.; Kozub, S.; Pleskach, V.; Sytnik, V.; Tkachenko, L.; Zintchenko, S.; Zubko, V.; Kuznetsov, G.; Sery, A.; Shiltsev, V.

    2000-01-01

    The Tevatron Electron Lens (TEL) system consisting of seven SC and four conventional magnets has been developed and fabricated in IHEP for increase of luminosity in Tevatron. The SC cable tension and preload of SC coils are calculated. The chosen cable design and cooling of the SC magnets ensure sufficient temperature margin for operating of SC magnets and their safety during quench. The system of conventional and SC solenoids create necessary trajectory of magnetic field lines for the TEL electron beam motion. SC dipoles and warm correctors permit to carry out correction of the electron beam motion [ru

  19. Septic lens implantation syndrome in a cat.

    Science.gov (United States)

    Dalesandro, Nicole; Stiles, Jean; Miller, Margaret

    2011-09-01

    A 13-year-old female spayed domestic shorthair cat was presented initially for a change in the appearance of the left eye. On initial examination, a small penetrating wound was suspected as the cause for a corneal scar, an anterior cortical incipient cataract and mild iritis. The cat was not re-presented until 1 year later at which time ocular pain was marked. Severe anterior uveitis and glaucoma were diagnosed and the eye enucleated. Histopathology documented intralenticular coccoid bacteria and septic lens implantation syndrome. © 2011 American College of Veterinary Ophthalmologists.

  20. [Contact lens-associated Paecilomyces lilacinus keratitis].

    Science.gov (United States)

    Mihailovic, N; Alnawaiseh, M; Zumhagen, L; Eter, N

    2017-01-01

    We present the case of a 23-year-old otherwise healthy female patient with contact lens-associated Paecilomyces lilacinus keratitis. The clinical findings stabilized after initial local antimycotic and antibacterial treatment; however, in the further course of local therapy an extensive relapse occurred which required treatment by perforating keratoplasty à chaud due to a penetrating corneal ulcer. The patient responded well to subsequent treatment with systemic and local antimycotic medication. After a few months HLA-matched keratoplasty was performed. During the follow-up time of 14 months there were no signs of recurrence of the infection.

  1. Scleral lens for keratoconus: technology update

    OpenAIRE

    Rathi, Varsha; Taneja,Mukesh; Mandathara,Preeji; Sangwan,Virender; Dumpati,Srikanth

    2015-01-01

    Varsha M Rathi,1 Preeji S Mandathara,2 Mukesh Taneja,1 Srikanth Dumpati,1 Virender S Sangwan1 1L V Prasad Eye Institute, Hyderabad, India; 2School of Optometry and Vision Science, University of New South Wales, Kensington, NSW, Australia Abstract: Scleral lenses are large diameter lenses which rest over the sclera, unlike the conventional contact lenses which rest on the cornea. These lenses are fitted to not touch the cornea and there is a space created between the cornea and the lens. Th...

  2. Scientific performance assessments through a gender lens

    DEFF Research Database (Denmark)

    Nielsen, Mathias Wullum

    2018-01-01

    The focus on excellence and quality assurance in the academy has spawned a signifi cant increase in the use of bibliometric measures in performance assessments of individual researchers. This article investigates the organizational consequences of this development through a gender lens. Based....... They adhere to the prevailing ethos of the academic meritocracy by standardizing the criteria for organizational advancement and ensuring transparency and accountability in the selection process. While bibliometric tools in this sense may lead to the recruitment of scientists with a strong CV and track record...

  3. Polarization response of RHIC electron lens lattices

    Directory of Open Access Journals (Sweden)

    V. H. Ranjbar

    2016-10-01

    Full Text Available Depolarization response for a system of two orthogonal snakes at irrational tunes is studied in depth using lattice independent spin integration. In particular we consider the effect of overlapping spin resonances in this system, to understand the impact of phase, tune, relative location and threshold strengths of the spin resonances. These results are benchmarked and compared to two dimensional direct tracking results for the RHIC e-lens lattice and the standard lattice. Finally we consider the effect of longitudinal motion via chromatic scans using direct six dimensional lattice tracking.

  4. International survey of contact lens prescribing for extended wear.

    Science.gov (United States)

    Efron, Nathan; Morgan, Philip B; Woods, Craig A

    2012-02-01

    To determine the extent of extended wear (EW) contact lens prescribing worldwide and to characterize the associated demographics and fitting patterns. Up to 1000 survey forms were sent to contact lens fitters in up to 39 countries between January and March every year for five consecutive years (2006-2010). Practitioners were asked to record data relating to the first 10 contact lens fits or refits performed after receiving the survey form. Survey data collected since 1997 was also analyzed to assess EW fitting trends since that time. Details for lens modality were received for 107,094 rigid and soft lens fits of which 88,392 were for soft lens daily wear (DW) and 7470 were for soft lens EW. Overall, EW represents 7.8% of all soft lens fits, ranging from 0.6% in Malaysia to 27% Norway. Compared with DW fittings, EW fittings can be characterized as follows: older age (32.7 ± 13.6 vs. 29.4 ± 12.0 years for DW); males are over-represented; greater proportion of refits; 72% silicone hydrogel; higher proportion of presbyopia and spherical designs; and higher proportion of monthly lens replacement. Of those wearing EW lenses, 80% use multipurpose solutions, whereas 9% do not use any care system. Between 1997 and 1999, the rate of EW prescribing decreased from 5 to 1% of all soft lens fits; it increased to a peak of 12% in 2006, and settled back to 8% by 2010. EW prescribing has failed to break through the "glass ceiling" of 15% and is unlikely to become a mainstream lens wearing modality until the already low risks of ocular complications can be reduced to be equivalent to that for DW.

  5. Light transmittance of 1-piece hydrophobic acrylic intraocular lenses with surface light scattering removed from cadaver eyes.

    Science.gov (United States)

    Werner, Liliana; Morris, Caleb; Liu, Erica; Stallings, Shannon; Floyd, Anne; Ollerton, Andrew; Leishman, Lisa; Bodnar, Zachary

    2014-01-01

    To assess the potential effect of surface light scattering on light transmittance of 1-piece hydrophobic acrylic intraocular lenses (IOLs) with or without a blue-light filter. John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. Experimental study. Intraocular lenses were obtained from human cadavers (49 IOLs total; 36 with blue-light filter) and from finished-goods inventory (controls). The IOLs were removed from cadaver eyes and the power and model matched to unused controls. After surface proteins were removed, the IOLs were hydrated for 24 hours at room temperature. Surface light scattering was measured with a Scheimpflug camera (EAS-1000 Anterior Segment Analysis System). Light transmittance was measured with a Lambda 35 UV/Vis spectrophotometer (single-beam configuration; RSA-PE-20 integrating sphere). Hydrated scatter values ranged from 4.8 to 202.5 computer-compatible tape (CCT) units for explanted IOLs with blue-light filter and 1.5 to 11.8 CCT units for controls; values ranged from 6.0 to 137.5 CCT units for explanted IOLs without a blue-light filter and 3.5 to 9.6 CCT units for controls. In both groups, there was a tendency toward increasing scatter values with increasing postoperative time. No differences in light transmittance were observed between explanted IOLs and controls in both groups (IOLs with blue-light filter: P=.407; IOL with no blue-light filter: P=.487; both paired t test). Although surface light scattering of explanted IOLs was significantly higher than that of controls and appeared to increase with time, no effect was observed on light transmittance of 1-piece hydrophobic acrylic IOLs with or without a blue-light filter. Copyright © 2013 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  6. Dose limits to the eye lens

    Energy Technology Data Exchange (ETDEWEB)

    Sion, N.

    2016-09-15

    Protecting the human body from the effects of ionizing radiation is essential to forestall stochastic effects and require placing limits on the effective dose. Dose limits on specific organs are also necessary to reduce the deterministic effects and tissue reactions. The standard for radiation protection was ISO 15382 (2002) which mainly dealt with beta radiation for nuclear power plant workers. Clearly an update is required to allow for new technology and the proliferative use of radiation in medical practices. There is a need for more explicit radiation monitoring to operators and staff. ICRP118 (International Commission on Radiological Protection), Ref. 1, evolved their recommendations to include eye lens doses as a follow on to their publication 103 and to focus on radiation exposures. It provides updated estimates of 'practical' threshold doses for tissue injury at the level of 1% incidence. This paper discusses the current status and the recommendation for a drastic reduction of the dose limit to the eye lens. (author)

  7. Scleral lens for keratoconus: technology update

    Directory of Open Access Journals (Sweden)

    Rathi VM

    2015-10-01

    Full Text Available Varsha M Rathi,1 Preeji S Mandathara,2 Mukesh Taneja,1 Srikanth Dumpati,1 Virender S Sangwan1 1L V Prasad Eye Institute, Hyderabad, India; 2School of Optometry and Vision Science, University of New South Wales, Kensington, NSW, Australia Abstract: Scleral lenses are large diameter lenses which rest over the sclera, unlike the conventional contact lenses which rest on the cornea. These lenses are fitted to not touch the cornea and there is a space created between the cornea and the lens. These lenses are inserted in the eyes after filling with sterile isotonic fluid. Generally, scleral contact lenses are used for high irregular astigmatism as seen in various corneal ectatic diseases such as keratoconus, pellucid marginal degeneration, or/and as liquid bandage in ocular surface disorders. In this article, we review the new developments, that have taken place over the years, in the field of scleral contact lenses as regard to new designs, materials, manufacturing technologies, and fitting strategies particularly for keratoconus. Keywords: keratoconus, scleral lens, technology update, PROSE

  8. Curiosity's Mars Hand Lens Imager (MAHLI) Investigation

    Science.gov (United States)

    Edgett, Kenneth S.; Yingst, R. Aileen; Ravine, Michael A.; Caplinger, Michael A.; Maki, Justin N.; Ghaemi, F. Tony; Schaffner, Jacob A.; Bell, James F.; Edwards, Laurence J.; Herkenhoff, Kenneth E.; Heydari, Ezat; Kah, Linda C.; Lemmon, Mark T.; Minitti, Michelle E.; Olson, Timothy S.; Parker, Timothy J.; Rowland, Scott K.; Schieber, Juergen; Sullivan, Robert J.; Sumner, Dawn Y.; Thomas, Peter C.; Jensen, Elsa H.; Simmonds, John J.; Sengstacken, Aaron J.; Wilson, Reg G.; Goetz, Walter

    2012-01-01

    The Mars Science Laboratory (MSL) Mars Hand Lens Imager (MAHLI) investigation will use a 2-megapixel color camera with a focusable macro lens aboard the rover, Curiosity, to investigate the stratigraphy and grain-scale texture, structure, mineralogy, and morphology of geologic materials in northwestern Gale crater. Of particular interest is the stratigraphic record of a ?5 km thick layered rock sequence exposed on the slopes of Aeolis Mons (also known as Mount Sharp). The instrument consists of three parts, a camera head mounted on the turret at the end of a robotic arm, an electronics and data storage assembly located inside the rover body, and a calibration target mounted on the robotic arm shoulder azimuth actuator housing. MAHLI can acquire in-focus images at working distances from ?2.1 cm to infinity. At the minimum working distance, image pixel scale is ?14 μm per pixel and very coarse silt grains can be resolved. At the working distance of the Mars Exploration Rover Microscopic Imager cameras aboard Spirit and Opportunity, MAHLI?s resolution is comparable at ?30 μm per pixel. Onboard capabilities include autofocus, auto-exposure, sub-framing, video imaging, Bayer pattern color interpolation, lossy and lossless compression, focus merging of up to 8 focus stack images, white light and longwave ultraviolet (365 nm) illumination of nearby subjects, and 8 gigabytes of non-volatile memory data storage.

  9. Near UV radiation effect on the lens and retina

    International Nuclear Information System (INIS)

    Zigman, S.

    1987-01-01

    The discussion presented in this paper indicates that the retina of a diurnal animal with a natural UV-absorbing lens (ie: the gray squirrel) is susceptible to near-UV damage from environmental sources only after the lens has been removed. This suggests that it is very important to protect against near-UV exposure of human eyes after cataract surgery

  10. Introduction to designing information and organizations with a positive lens

    NARCIS (Netherlands)

    Avital, M.; Boland, R.J.; Lyytinen, K.

    2009-01-01

    The role and potential contribution of a positive lens to the design of systems and organizations is the focus of this introductory essay. The positive lens refers to a perspective in the social sciences that emphasizes the capacity of people and organizations to construct better work environments,

  11. Isofocusing and immunological investigations on cephalopod lens proteins

    NARCIS (Netherlands)

    Brahma, S.K.; Lancieri, M.

    1979-01-01

    Soluble lens proteins from Octopus vulgaris, Sepia officinalis, and Loligo vulgaris were analyzed by thin-layer isoelectric focusing and compared by various immunochemical methods using antibodies directed against total soluble lens protein antigens from the said three species. The results show

  12. RETINAL BREAKS IN VITRECTOMY FOR RETAINED LENS FRAGMENTS

    NARCIS (Netherlands)

    Tan, H. Stevie; Mura, Marco; Oberstein, Sarit Y. Lesnik; Bijl, Heico M.

    2012-01-01

    Purpose: To describe the incidence and outcome of retinal breaks in vitrectomy for retained lens fragments. Methods: This is a retrospective noncomparative interventional case series. Medical records of consecutive cases of vitrectomy for retained lens fragments over a period of 4 years were

  13. The NNEST lens non native english speakers in TESOL

    CERN Document Server

    Mahboob, Ahmar

    2010-01-01

    The NNEST Lens invites you to imagine how the field of TESOL and applied linguistics can develop if we use the multilingual, multicultural, and multinational perspectives of an NNEST lens to re-examine our assumptions, practices, and theories in the field

  14. The "Youth Lens": Analyzing Adolescence/ts in Literary Texts

    Science.gov (United States)

    Petrone, Robert; Sarigianides, Sophia Tatiana; Lewis, Mark A.

    2014-01-01

    Drawing from interdisciplinary scholarship that re-conceptualizes adolescence as a cultural construct, this article introduces a "Youth Lens." A "Youth Lens" comprises an approach to textual analysis that examines how ideas about adolescence and youth get formed, circulated, critiqued, and revised. Focused specifically on its…

  15. Optimized lens-sparing treatment of retinoblastoma with electron beams

    NARCIS (Netherlands)

    Steenbakkers, RJHM; Altschuler, MD; DAngio, GJ; Goldwein, JW; Kassaee, A

    1997-01-01

    Purpose: The ideal lens-sparing radiotherapy technique for retinoblastoma calls for 100% dose to the entire retina including the ora serrata and zero dose to the lens, Published techniques, most of which use photons, have not accomplished this ideal treatment. We describe here a technique that

  16. A Broadband Metasurface-Based Terahertz Flat-Lens Array

    KAUST Repository

    Wang, Qiu

    2015-02-12

    A metasurface-based terahertz flat-lens array is proposed, comprising C-shaped split-ring resonators exhibiting locally engineerable phase discontinuities. Possessing a high numerical aperture, the planar lens array is flexible, robust, and shows excellent focusing characteristics in a broadband terahertz frequency. It could be an important step towards the development of planar terahertz focusing devices for practical applications.

  17. Prevalence of corneal ulcer among contact lens wearers in Nigeria ...

    African Journals Online (AJOL)

    Corneal Ulceration has been described as the most serious complication of contact lens wear worldwide. The incidence of corneal ulceration in contact lens wearers in Nigeria was determined retrospectively. 1759 case notes of patients who had worn contact lenses for at least one year were obtained from eye clinics in ...

  18. Incidence of contact lens-associated microbial keratitis

    NARCIS (Netherlands)

    Cheng, K.H.; Leung, S.L.; Hoekman, J.W.; Beekhuis, W.H.; Mulder, P.G.H.; Geerards, A.J.M.; Kijlstra, A.

    1999-01-01

    Background. The incidence of contact-lens-associated microbial keratitis is uncertain and its related morbidity in the general population of contact-lens wearers is not known. We examined these issues in a prospective epidemiological study. Methods. We surveyed all practising ophthalmologists in the

  19. Preparing Teacher Candidates to Integrate Reading and Writing Instruction: A Conceptual Piece

    Science.gov (United States)

    Nicholas, Erika L.

    2017-01-01

    This piece focuses on increasing writing instruction for secondary English teacher candidates in the form of integrating reading and writing. Often, teacher candidates are not sufficiently prepared in university coursework to teach writing and are left to rely on formulaic writing that merely prepares their students for the end-of-year tests.…

  20. Comparison of the T-piece resuscitator with other neonatal manual ventilation devices: A qualitative review.

    LENUS (Irish Health Repository)

    2012-01-31

    AIM: To review the literature surrounding various aspects of T-piece resuscitator use, with particular emphasis on the evidence comparing the device to other manual ventilation devices in neonatal resuscitation. DATA SOURCES: The Medline, EMBASE, Cochrane databases were searched in April 2011. Ongoing trials were identified using www.clinicaltrials.gov and www.controlled-trials.com. Additional studies from reference lists of eligible articles were considered. All studies including T-piece resuscitator use were eligible for inclusion. RESULTS: Thirty studies were included. There were two randomised controlled trials in newborn infants comparing the devices, one of which addressed short and intermediate term morbidity and mortality outcomes and found no difference between the T-piece resuscitator and self inflating bag. From manikin studies, advantages to the T-piece resuscitator include the delivery of inflating pressures closer to predetermined target pressures with least variation, the ability to provide prolonged inflation breaths and more consistent tidal volumes. Disadvantages include a technically more difficult setup, more time required to adjust pressures during resuscitation, a larger mask leak and less ability to detect changes in compliance. CONCLUSIONS: There is a need for appropriately designed randomised controlled trials in neonates to highlight the efficacy of one device over another. Until these are performed, healthcare providers should be appropriately trained in the use of the device available in their departments, and be aware of its own limitations.

  1. Pelvic abscess as a result of incorrect three-piece implant usage

    Directory of Open Access Journals (Sweden)

    Yu. G. Alyaev

    2014-11-01

    Full Text Available The case presented is a demonstrative example of dangerous complication after penile prothesis implantation. Pelvic abscess with purulent fistula was a result of incorrect three-piece implant usage. Infectious complication was caused by the reservoir of the implant. In the event of such complications is necessary to use the full range of modern methods of radiation diagnosis.

  2. Pelvic abscess as a result of incorrect three-piece implant usage

    Directory of Open Access Journals (Sweden)

    Yu. G. Alyaev

    2013-01-01

    Full Text Available The case presented is a demonstrative example of dangerous complication after penile prothesis implantation. Pelvic abscess with purulent fistula was a result of incorrect three-piece implant usage. Infectious complication was caused by the reservoir of the implant. In the event of such complications is necessary to use the full range of modern methods of radiation diagnosis.

  3. Ways of Knowing and Types of Knowledge: How Do Students Approach a New Piece of Music?

    Science.gov (United States)

    dos Santos, Regina Antunes Teixeira; Gerling, Cristina Capparelli

    2012-01-01

    In an exploratory study lasting more than 16 weeks, 15 undergraduate and graduate piano students prepared a short piece by the Brazilian composer Guarnieri, "Ponteio" no. 22, without guidance from their piano teachers. The data that were collected included their performances, interviews pertaining to their practice and stimulated recall…

  4. Debris filtering effectiveness and pressure drop tests of debris resistance-bottom end piece

    International Nuclear Information System (INIS)

    Chung, Moon Ki; Song, Chul Hwa; Chung, Heung June; Won, Soon Yeun; Cho, Young Ro; Kim, Bok Deuk

    1992-03-01

    In this final report, described are the test conditions and test procedures for the debris filtering effectiveness and pressure drop tests for developing the Debris Resistance-Bottom End Piece (DR-BEP). And the test results are tabulated for later evaluation. (Author)

  5. Flight Performance of an Advanced Thermal Protection Material: Toughened Uni-Piece Fibrous Insulation

    Science.gov (United States)

    Leiser, Daniel B.; Gordon, Michael P.; Rasky, Daniel J. (Technical Monitor)

    1995-01-01

    The flight performance of a new class of low density, high temperature thermal protection materials (TPM) is described and compared to "standard" Space Shuttle TPM. This new functionally gradient material designated as Toughened Uni-Piece Fibrous Insulation (TUFI), was bonded on a removable panel attached to the base heat shield of Orbiter 105, Endeavour.

  6. On the question of the capacity of warehouses of packaged-piece cargoes

    Directory of Open Access Journals (Sweden)

    Ilesaliev D.I.

    2017-06-01

    Full Text Available Mathematical models are proposed that establish interrelations between the individual parameters of a warehouse of packaged piece cargo. The models were used in the study of the mutual influence of the parameters on each other, also the capacity of the warehouses of packaged cargo

  7. [Development of Chinese herbal pieces and analysis of problems of total quality management].

    Science.gov (United States)

    Wang, Jie; Qiao, Xi-yao; Lin, Fei; Chen, Yin-feng

    2014-11-01

    Chinese herbal pieces are a key factor to protecting the quality of the clinical efficacy of traditional Chinese medicine (TCM), and it is one of the basic elements of ensuring the quality of TCM and people's usage safety. However, Chinese herbal pieces has massive problem such as adulteration and counterfeit, dyeing and weighting, pesticide residues, heavy metals in excess of the standards, and all the issues are repeated excessive in the clinic treatment. These issues impacted sound development of production, management and use of TCM, but also brings common people hidden trouble for the clinical safety of medication. Protect and improve the quality of the Chinese herbal pieces demand that continue improve quality system, in-depth scientific research, and strengthen self-discipline and other factors. So it is fundamentally to ensure good quality of Chinese herbal pieces with the color, taste and shape by systematic supervision to it from the source, production, management and research, with strengthened implementation and en- forcement of the "3G".

  8. Grafted fetal suprachiasmatic nucleus cells survive much better in tissue pieces than in suspension

    NARCIS (Netherlands)

    Boer, G. J.; Griffioen, H. A.; Saeed, P.

    1992-01-01

    A comparison was made between the survival of fetal suprachiasmatic nucleus (SCN) grafted either in tissue pieces or as tissue suspension. Donor tissue was obtained from day 15, 16 or 17 Wistar fetuses, and stereotaxically placed in the dorsal thalamus of the brain of vasopressin(VP)-deficient

  9. Fascia compared to one-piece composite cartilage-perichondrium grafting for tympanoplasty

    NARCIS (Netherlands)

    Lyons, Sarah A.|info:eu-repo/dai/nl/413920984; Su, Tanly; Vissers, Linda E T|info:eu-repo/dai/nl/413985652; Peters, Jeroen P M|info:eu-repo/dai/nl/413968960; Smit, Adriana L|info:eu-repo/dai/nl/413982084; Grolman, Wilko|info:eu-repo/dai/nl/175476136

    2016-01-01

    OBJECTIVE: To evaluate the effectiveness of type 1 tympanoplasty with one-piece composite cartilage-perichondrium (CCP) grafts compared to temporalis fascia (TF) grafts for tympanic membrane (TM) closure and hearing improvement in adult patients with a subtotal TM perforation and chronic otitis

  10. Structural Optimization of an Offshore Wind Turbines Transition Pieces for Bucket Foundations

    DEFF Research Database (Denmark)

    Nezhentseva, Anastasia; Andersen, Lars Vabbersgaard; Ibsen, Lars Bo

    Traditionally, offshore constructions are made of steel. The focus of this paper is optimization of a transition piece (TP) connecting the offshore wind turbine column with a suction bucket foundation. Suction caissons, typically used for shallow water depths, have been proved to be adequate...

  11. One-piece, composite crucible with integral withdrawal/discharge section

    Science.gov (United States)

    Besser, Matthew; Terpstra, Robert L.; Sordelet, Daniel J.; Anderson, Iver E.; Hartman, Alan D.; Argetsinger, Edward R.; Hansen, Jeffrey S.; Paige, Jack I.; Turner, Paul C.

    2002-07-30

    A one-piece, composite open-bottom casting mold with integral withdrawal section is fabricated by thermal spraying of materials compatible with and used for the continuous casting of shaped products of reactive metals and alloys such as, for example, titanium and its alloys or for the gas atomization thereof.

  12. Joining the Pieces: Using Concept Maps for Integrated Learning and Assessment in an Introductory Management Course

    Science.gov (United States)

    Connolly, Heather; Spiller, Dorothy

    2016-01-01

    This paper reports on and evaluates the use of concept mapping as a learning tool in a large first year Management course. The goal was to help students make personal sense of course learning and to build their understanding of links and relationships between key course ideas. Concept mapping was used for three summative assessment pieces,…

  13. Material Composition of Bucket Foundation Transition Piece for Offshore Wind Turbines

    DEFF Research Database (Denmark)

    Nezhentseva, Anastasia; Andersen, Lars; Ibsen, Lars Bo

    2010-01-01

    the structural behaviour of a transition piece made of steel (reference case), compact reinforced composite (CRC) and composite shell elements made of CRC glued to steel sheets. A finite-element model is developed in ABAQUS. Three material models are checked for buckling and material failure in the Ultimate...

  14. Enterocyte Damage: A Piece in the Puzzle of Post-Cardiac Arrest Syndrome.

    Science.gov (United States)

    Piton, Gaël; Belin, Nicolas; Barrot, Loïc; Belon, François; Cypriani, Benoit; Navellou, Jean-Christophe; Capellier, Gilles

    2015-11-01

    Cardiac arrest is considered to be a cause of small bowel ischemia, but the consequences of cardiac arrest on the human small bowel have been rarely studied. Plasma citrulline concentration is a marker of functional enterocyte mass, and plasma intestinal fatty acid-binding protein (I-FABP) concentration is a marker of enterocyte damage. We aimed to measure enterocyte biomarkers after cardiac arrest and to study the prognostic value of biomarker abnormalities. This is a prospective, observational, single-center study of patients admitted to the intensive care unit (ICU) for cardiac arrest, evaluating plasma citrulline and I-FABP concentrations at admission and after 24  h and variables according to the Utstein criteria. Variables according to 28-day Cerebral Performance Category score of 1 to 2 (good neurological outcome) versus 3 to 5 (poor neurological outcome) were compared. Sixty-nine patients with cardiac arrest of both cardiac and hypoxic origin were included. At ICU admission, plasma citrulline concentration was low in 65% and plasma I-FABP was elevated in 82% of the patients. After 24  h, plasma citrulline was low in 82% and I-FABP was normal in 60% of the patients. Patients with a poor neurological outcome had a lower plasma citrulline concentration and a higher I-FABP concentration at ICU admission. By multivariate analysis, plasma citrulline levels of 13.1  μmol L or less and I-FABP more than 260  pg mL were independently associated with a poor neurological outcome (odds ratio, 21.9 [2.2-215], and odds ratio, 13.6 [1.4-129], respectively). Cardiac arrest resuscitation is associated with evidence of small bowel mucosal damage in most patients, with a short and intense I-FABP elevation at admission and a decrease in citrulline concentration during the first day. In this study, low plasma citrulline and high I-FABP concentrations at ICU admission were predictive of a poor neurological outcome. This study confirms that cardiac arrest is a model of

  15. A novel device for resonance frequency assessment of one-piece implants.

    Science.gov (United States)

    Gabay, Eran; Cohen, Omer; Machtei, Eli E

    2012-01-01

    Immediate loading and/or restoration of dental implants requires the assessment of implant stability, which is best performed by resonance frequency analysis (RFA) prior to loading. One-piece dental implants are usually used for immediate loading, but there is currently no available reliable method to assess the primary stability of one-piece dental implants. Therefore, this study sought to validate a novel device designed for RFA measurements of one-piece implants. Thirty (3.75 x 13 mm) internal-hex implants (Seven, MIS) were divided into two groups; 15 were placed in an acrylic glass block and 15 were placed in fresh porcine jawbone using 30 N/cm2 of insertion torque. Implant stability quotient (ISQ) values were measured using the Osstell Mentor device; then, a new external fixation device was attached to the implant abutment with a 10-mm arm extending from the implant to an internal-hex ring at its proximal end. ISQ values were measured at the implant's internal hex and at the internal hex of the device, and the damping ratio was calculated. The measurements were repeated with 15 (3 x 13 mm) one-piece implants (UNO, MIS) attached to the same device. The damping ratio between the implant and the proximal device was 23.6% ± 4% in acrylic glass (50.1 ± 1.7 ISQ and 38.2 ± 1.8 ISQ, respectively) and 23.1% ± 3% in porcine bone (74.9 ± 2.8 ISQ and 57.5 ± 0.5 ISQ, respectively). ISQ values determined by the device on one-piece and two-piece implants were similar (57.4 ± 0.9 and 57.5 ± 0.5, respectively). With the present validation of this external fixation device for the measurements of implant stability using RFA, it is now possible to measure primary stability of any one-piece implant system, obviating the need for custom-made Osstell adaptors.

  16. [GA(2)LEN (Global Allergy and Asthma European Network): European network of excellence for asthma and allergic diseases].

    Science.gov (United States)

    Gjomarkaj, M; Pace, E; Canonica, G W; Bonini, S; Ricci, G; Burney, P; Zuberbier, T; Van Cauwenberge, P; Bousquet, J

    2009-12-01

    Allergic diseases represent some of the main health problems in Europe. These are increasing in prevalence, seriousness and social cost. The Global Allergy and Asthma European Network (GA(2)LEN), a network of excellence of the 6 degrees management program, was created in the 2005 with the aim to gather the European leader institutions of the research and clinical assistance fields, in order to guarantee the excellence and avoid the fragmentation of the energy spent in fighting allergy diseases in general. The GA(2)LEN has drawn a great advantage from the personal efforts of every single researcher who have proved their strong motivation in carrying on this "pan-European" model of collaboration. The network has been organized in order to increase the team work in scientific research projects in allergic and asthma disease field, making the GA(2)LEN the worldwide leader in this area. On these basis research projects have been carried on about which first data have been already published. The activities of the GA(2)LEN include in general the establishment of a lasting organization of the planning phase, the activity linked to every single project and to the improving on the existing projects, as well as the draft of new guidelines. This review reports the main achieved goals.

  17. Patient acceptability of the Tecnis® multifocal intraocular lens

    Directory of Open Access Journals (Sweden)

    Sood P

    2011-03-01

    Full Text Available Priyanka Sood1, Maria A Woodward21Emory Eye Center, Atlanta, GA, USA; 2Kellogg Eye Center, Ann Arbor, MI, USAAbstract: Cataract surgery has evolved. The goal of the surgeon includes both restoration of vision and refinement of vision. Patients' desire for spectacle independence has driven the market for presbyopia-correcting cataract surgery and development of novel intraocular lens (IOL designs. The Tecnis® Multifocal Intraocular Lens incorporates an aspheric, modified anterior prolate IOL with a diffractive multifocal lens design. The design aims to minimize spherical aberration and improve range of focus. The purpose of this review is to assess patient acceptability of the Tecnis® multifocal intraocular lens.Keywords: Tecnis®, intraocular lens, multifocal, presbyopia 

  18. Composite modified Luneburg model of human eye lens.

    Science.gov (United States)

    Gómez-Correa, J E; Balderas-Mata, S E; Pierscionek, B K; Chávez-Cerda, S

    2015-09-01

    A new lens model based on the gradient-index Luneburg lens and composed of two oblate half spheroids of different curvatures is presented. The spherically symmetric Luneburg lens is modified to create continuous isoindicial contours and to incorporate curvatures that are similar to those found in a human lens. The imaging capabilities of the model and the changes in the gradient index profile are tested for five object distances, for a fixed geometry and for a fixed image distance. The central refractive index decreases with decreasing object distance. This indicates that in order to focus at the same image distance as is required in the eye, a decrease in refractive power is needed for rays from closer objects that meet the lens surface at steeper angles compared to rays from more distant objects. This ensures a highly focused image with no spherical aberration.

  19. Design of LED projector based on gradient-index lens

    Science.gov (United States)

    Qian, Liyong; Zhu, Xiangbing; Cui, Haitian; Wang, Yuanhang

    2018-01-01

    In this study, a new type of projector light path is designed to eliminate the deficits of existing projection systems, such as complex structure and low collection efficiency. Using a three-color LED array as the lighting source, by means of the special optical properties of a gradient-index lens, the complex structure of the traditional projector is simplified. Traditional components, such as the color wheel, relay lens, and mirror, become unnecessary. In this way, traditional problems, such as low utilization of light energy and loss of light energy, are solved. With the help of Zemax software, the projection lens is optimized. The optimized projection lens, LED, gradient-index lens, and digital micromirror device are imported into Tracepro. The ray tracing results show that both the utilization of light energy and the uniformity are improved significantly.

  20. Dielectrically embedded flat mesh lens for millimeter waves applications.

    Science.gov (United States)

    Pisano, Giampaolo; Ng, Ming Wah; Ozturk, Fahri; Maffei, Bruno; Haynes, Vic

    2013-04-10

    A flat lens based on subwavelength periodic metal meshes has been developed using photolithographic techniques. These mesh grids are stacked at specific distances and embedded in polypropylene. A code was developed to optimize more than 1000 transmission line circuits required to vary the device phase shift across the lens flat surface, mimicking the behavior of a classical lens. A W-band mesh-lens prototype was successfully manufactured and its RF performance characterized using a vector network analyzer coupled to corrugated horn antennas. Co-polarization far-field beam patterns were measured and compared with finite-element method models. The excellent agreement between data and simulations validated our designing tools and manufacturing procedures. This mesh lens is a low-loss, robust, light, and compact device that has many potential applications including millimeter wave quasi-optical systems for future cosmic microwave background polarization instruments.