WorldWideScience

Sample records for cellulose ophthalmic inserts

  1. Review of hydroxypropyl cellulose ophthalmic inserts for treatment of dry eye

    Directory of Open Access Journals (Sweden)

    Nguyen T

    2011-05-01

    Full Text Available Theresa Nguyen, Robert LatkanyDry Center, Physician Eyecare of New York, New York, NY, USAAbstract: Dry eye syndrome is a prevalent disease that affects visual acuity, activities of daily living, and quality of life. A number of contributory factors affect the severity of dry eye syndrome, including autoimmune disease, environmental surroundings, contact lens use, hormonal changes, anatomical features, chronic inflammation, infections, and iatrogenic factors, such as medications or surgery. Symptoms may include intermittent or constant blurry vision, discomfort, burning, foreign body sensation, hyperemia, dryness, and photophobia. The severity of dry eye syndrome can range from very mild disease to extremely severe cases with vision-threatening consequences. A variety of dry eye treatment modalities exist to address the different causes, symptoms, and consequences of ocular surface disease, including artificial tears, lubricating gels, ophthalmic inserts, anti-inflammatory drops, and surgical procedures. In this paper, an assortment of literature pertaining to the treatment of dry eye syndrome, in particular hydroxypropyl cellulose ophthalmic inserts, is reviewed. These inserts can be used effectively as monotherapy, or in conjunction with other therapies, and should be considered in the treatment of dry eye syndrome.Keywords: hydroxypropyl cellulose ophthalmic inserts, dry eye, punctal occlusion, ocular surface disease

  2. Iodine-125 ophthalmic applications with monolithic active insert

    International Nuclear Information System (INIS)

    A prototype ophthalmic applicator for conservative treatment of intraocular tumors was designed in 1985 by Klemp et al. This served to retain a number of 'seed-type' sources of iodine-125. Such applicator consists of two major parts: a seed-holding acrylic insert, spherically shaped, with drilled trenches on the convex side to accommodate the seeds, and a stainless steel shell capsule serving as radiation shield. This design proved to be difficult and hazardous to assemble and dismantle after usage. As these problems appeared likely to persist if not attended to, development of the applicator was undertaken in order to eliminate the necessity of using iodine seeds. The investigations preformed comprised uniform adsorption of iodine-125 on the concave surface of the silver shell and its hermetic sealing inside spherically shaped acrylic insert. The method of fixing iodine-125 on silver as well as the technique of its sealing in acryl is described. The results of the classification testing for performance requirements of the assembled applicator are quoted. Comparative measurements of the energy spectra of the radiation emitted by both the seed-less and seed-containing applicators are presented. From the results of the depth dose rate measurements it follows that the total activity incorporated in a seed-less applicator can be much lower than in seed-containing one without decrease in the dose rate value. (author)

  3. Ophthalmic viscosurgical device backflow into cartridge during intraocular lens insertion using injectors

    Directory of Open Access Journals (Sweden)

    Matsuura K

    2014-01-01

    Full Text Available Kazuki Matsuura,1 Yoshitsugu Inoue2 1Nojima Hospital, 2Tottori University, Kurayoshi City, Tottori, Japan Background: The purpose of this study was to assess the risk of intraocular contamination caused by intraocular lens (IOL insertion with injectors by observing the dynamics of an ophthalmic viscosurgical device (OVD. Methods: Each type of injector was equipped with a colored OVD and IOL, and a 2 mm length from the tip of the cartridge was replaced with a colored OVD. The various combinations of IOLs and injectors used were: a three-piece shaped IOL, VA60BBR + TypeE1 (HOYA incision size 2.5 mm; group A, n=5; a single-piece IOL, 251+ iSert micro, preloaded (HOYA, incision size 2.2 mm; group G, n=5; and a single-piece IOL, SN6CWS preloaded (Alcon, incision size 2.7 mm; group C, n=5. Results: In group A, the intraocular OVD instantly flowed backward into the injector, whereas the colored OVD was pushed backward deep inside the cartridge without flowing into the eye. In group B, the backflow of the intraocular OVD into the injector was limited, resulting in the influx of a large amount of the colored OVD into the eye along with the IOL. In group C, as in group A, a large amount of the intraocular OVD flowed backward into the injector. Consequently, a small amount of the colored OVD flowed into the eye. Conclusion: The tip of the injector and OVD could be contaminated because the surgical field cannot be completely sterile, even after preoperative disinfection. Our experiments revealed that OVD backflow into the injector cavity occurs during IOL insertion, and this phenomenon may have minimized intraocular contamination. However, small-diameter cartridges along with plate-type haptics allow insufficient OVD backflow, resulting in intraocular influx of the contaminated OVD. Surgeons have to be notified that intraoperative bacterial contamination can occur even after IOL insertion using injectors. Keywords: intraocular lens insertion

  4. Cellulose

    Science.gov (United States)

    Cellulose properties and structure are reviewed, with a primary focus on crystal structure and polymorphy. This focus highlights the conversion from cellulose I to cellulose II, which converts the molecules to being all parallel to each other in the crystal to being antiparallel. This has been co...

  5. Ciprofloxacin Ophthalmic

    Science.gov (United States)

    Ciprofloxacin ophthalmic solution is used to treat bacterial infections of the eye including conjunctivitis (pinkeye; infection of ... in the clear front part of the eye). Ciprofloxacin ophthalmic ointment is used to treat conjunctivitis. Ciprofloxacin ...

  6. Gentamicin Ophthalmic

    Science.gov (United States)

    Garamycin® Ophthalmic ... Ophthalmic gentamicin is used to treat certain eye infections. Gentamicin is in a class of medications called antibiotics. It works by killing the bacteria that cause infection.

  7. Erythromycin Ophthalmic

    Science.gov (United States)

    Romycin® Ophthalmic ... Ophthalmic erythromycin is used to treat bacterial infections of the eye. This medication is also used to prevent bacterial infections of the eye in newborn babies. Erythromycin is in a class ...

  8. Semisolid ophthalmic vehicles.

    Science.gov (United States)

    Giannaccini, B; Alderigi, C

    1989-09-01

    The present review is concerned with some essential formulative and therapeutic aspects of semisolid ophthalmic vehicles. The history and the most recent developments of the traditional lipophilic vehicles (ointments) are first outlined. The hydrophilic vehicles (hydrogels) based on synthetic polymers (polyacrylates, PEG, PVA, Pluronics, etc.), semisynthetic polymers (cellulose derivatives) and natural polymers (hyaluronic and polygalacturonic acid, alginates, etc.) are then examined. Some recent formulations of particular type are finally described. PMID:2699716

  9. Moxifloxacin Ophthalmic

    Science.gov (United States)

    Moxifloxacin ophthalmic solution is used to treat bacterial conjunctivitis (pink eye; infection of the membrane that covers ... the eyeballs and the inside of the eyelids). Moxifloxacin is in a class of antibiotics called fluoroquinolones. ...

  10. Cyclosporine Ophthalmic

    Science.gov (United States)

    Ophthalmic cyclosporine is used to increase tear production in people with dry eye disease. Cyclosporine is in a class of medications ... immunomodulators. It works by decreasing swelling in the eye to allow for tear production.

  11. Diclofenac Ophthalmic

    Science.gov (United States)

    Voltaren® Eye Drops ... Diclofenac ophthalmic solution is used to treat eye pain, redness, and swelling in patients who are recovering from cataract surgery (procedure to treat clouding of the lens in the eye). Diclofenac ...

  12. Brinzolamide Ophthalmic

    Science.gov (United States)

    Ophthalmic Brinzolamide is used to treat glaucoma, a condition that increases pressure in the eye and leads to vision loss. Brinzolamide is in ... anhydrase inhibitors. It decreases the pressure in the eye.

  13. Ophthalmic Lenses

    CERN Document Server

    Bhootra, Ajay Kumar

    2009-01-01

    This book is uniquely meant for the ophthalmologists, optometrists and opticians to help the world see better by excellent vision through the services of technicians and clinical principle based ophthalmology so that the management of ocular problems can be done for a better vision . Informs that a wide range of material and design of ophthalmic lenses with innovative developments is available. This book presents comprehensively rich information about the ophthalmic lenses and their dispensing tips . It will be highly useful mainly for the students of optometry and opticians, ophthalmologists,

  14. Ophthalmic ultrasonography

    International Nuclear Information System (INIS)

    Today, diagnostic ultrasound is an important and indispensable part of modern ophthalmology. These proceedings present an up-to-date platform of SIDUO research, and bring to light many interesting and useful contributions to ophthalmic ultrasound, both in the fields of educational work and of new scientific results and technical developments. This volume covers topics such as intraocular tumours, vitreo-retinal pathology, other types of intraocular pathology, biometry for lens implantation, clinical biometry, orbital tumours, plus the optic nerve and muscles, among other subjects. There is also an important section on the physics and techniques of ophthalmic ultrasonography. (orig.)

  15. Ciprofloxacin Ophthalmic

    Science.gov (United States)

    ... of the following symptoms, call your doctor immediately: rash hives itching tingling swelling of the face, throat, tongue, lips, eyes, hands, feet, ankles, or lower legs difficulty breathing or swallowing hoarseness Ophthalmic ciprofloxacin may cause other side effects. Call your doctor ...

  16. Travoprost Ophthalmic

    Science.gov (United States)

    Travoprost ophthalmic is used to treat glaucoma (a condition in which increased pressure in the eye can lead to gradual loss of vision) and ... a condition which causes increased pressure in the eye). Travoprost is in a class of medications called ...

  17. Tafluprost Ophthalmic

    Science.gov (United States)

    Tafluprost ophthalmic is used to treat glaucoma (a condition in which increased pressure in the eye can lead to gradual loss of vision) and ... a condition which causes increased pressure in the eye). Tafluprost is in a class of medications called ...

  18. Latanoprost Ophthalmic

    Science.gov (United States)

    Latanoprost ophthalmic is used to treat glaucoma (a condition in which increased pressure in the eye can lead to gradual loss of vision) and ... a condition which causes increased pressure in the eye). Latanoprost is in a class of medications called ...

  19. Unoprostone Ophthalmic

    Science.gov (United States)

    Unoprostone ophthalmic is used to treat glaucoma (a condition in which increased pressure in the eye can lead to gradual loss of vision) and ... a condition which causes increased pressure in the eye). It is in a class of medications called ...

  20. Bimatoprost Ophthalmic

    Science.gov (United States)

    Bimatoprost ophthalmic is used to treat glaucoma (a condition in which increased pressure in the eye can lead to gradual loss of vision) and ... a condition which causes increased pressure in the eye). Bimatoprost is in a class of medications called ...

  1. A reusable iodine-125 seed ophthalmic applicator

    International Nuclear Information System (INIS)

    A reusable iodine-125 seed ophthalmic applicator has been manufactured to treat intraocular tumours. It is made up of a stainless steel cap which houses a perspex insert; the perspex insert is used to contain four I-125 seeds. This applicator will treat a tumour with a surface diameter of 10mm and when loaded with four seeds each of activity 150MBq a dose of 60Gy may be delivered to a depth of 5mm in the eye in 5 to 6 days. The resultant dose to the sclera is of the order of 220Gy

  2. Radiosterilized tetracycline ophthalmic ointment

    International Nuclear Information System (INIS)

    The likelihood of FDA approval for a radiosterilized ophthalmic ointment has been resolved. This paper reviews the events that led to Lederle's NDA submission in 1973. The cost savings feature of 60Co γ ray sterilization in the final package makes it an attractive alternate to conventional aseptic manufacturing and packaging. (U.S.)

  3. Seed-less iodine-125 ophthalmic applicator

    International Nuclear Information System (INIS)

    A method of preparation a seed-less active insert of iodine-125 ophthalmic applicator is described. Internal electrolysis was applied for fixing iodine-125 on the concave surface of the silver shell which is afterwards hermetically sealed inside a spherically shaped acrylic insert. The current-voltage characteristics of the galvanic cell used for deposition of silver iodide were determined. The results of the measurements of the energy spectra of the radiation emitted by a seed-less and seed-containing applicator are presented. The iodine-125 surface distribution uniformity on a silver shell was measured. The depth dose rate measurements indicate that the total activity incorporated in a seed-less applicator can be lower than that in seed-containing, while simultaneously assuring the desired dose rate

  4. 21 CFR 886.4390 - Ophthalmic laser.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic laser. 886.4390 Section 886.4390 Food... DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4390 Ophthalmic laser. (a) Identification. An ophthalmic laser is an AC-powered device intended to coagulate or cut tissue of the eye, orbit, or surrounding...

  5. 21 CFR 886.3130 - Ophthalmic conformer.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic conformer. 886.3130 Section 886.3130...) MEDICAL DEVICES OPHTHALMIC DEVICES Prosthetic Devices § 886.3130 Ophthalmic conformer. (a) Identification. An ophthalmic conformer is a device usually made of molded plastic intended to be...

  6. 21 CFR 886.1640 - Ophthalmic preamplifier.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic preamplifier. 886.1640 Section 886.1640...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1640 Ophthalmic preamplifier. (a) Identification. An ophthalmic preamplifier is an AC-powered or battery-powered device intended to...

  7. 21 CFR 886.4690 - Ophthalmic photocoagulator.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic photocoagulator. 886.4690 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4690 Ophthalmic photocoagulator. (a) Identification. An ophthalmic photocoagulator is an AC-powered device intended to use the energy from an...

  8. 21 CFR 886.1760 - Ophthalmic refractometer.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic refractometer. 886.1760 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1760 Ophthalmic refractometer. (a) Identification. An ophthalmic refractometer is an automatic AC-powered device that consists of a fixation...

  9. 21 CFR 886.4790 - Ophthalmic sponge.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic sponge. 886.4790 Section 886.4790 Food... DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4790 Ophthalmic sponge. (a) Identification. An ophthalmic sponge is a device that is an absorbant sponge, pad, or spear made of folded gauze,...

  10. 21 CFR 886.1140 - Ophthalmic chair.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic chair. 886.1140 Section 886.1140 Food... DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1140 Ophthalmic chair. (a) Identification. An ophthalmic chair is an AC-powered or manual device with adjustable positioning in which a patient is to...

  11. 21 CFR 886.1680 - Ophthalmic projector.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic projector. 886.1680 Section 886.1680...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1680 Ophthalmic projector. (a) Identification. An ophthalmic projector is an AC-powered device intended to project an image on a screen for...

  12. Ophthalmic epidemiology in Europe

    DEFF Research Database (Denmark)

    Delcourt, Cécile; Korobelnik, Jean-François; Buitendijk, Gabriëlle H S;

    2015-01-01

    The European Eye Epidemiology (E3) consortium is a recently formed consortium of 29 groups from 12 European countries. It already comprises 21 population-based studies and 20 other studies (case-control, cases only, randomized trials), providing ophthalmological data on approximately 170,000 Euro......The European Eye Epidemiology (E3) consortium is a recently formed consortium of 29 groups from 12 European countries. It already comprises 21 population-based studies and 20 other studies (case-control, cases only, randomized trials), providing ophthalmological data on approximately 170......,000 European participants. The aim of the consortium is to promote and sustain collaboration and sharing of data and knowledge in the field of ophthalmic epidemiology in Europe, with particular focus on the harmonization of methods for future research, estimation and projection of frequency and impact of...

  13. Polymyxin B and Trimethoprim Ophthalmic

    Science.gov (United States)

    ... and trimethoprim ophthalmic combination is used to treat bacterial infections of the eye including conjunctivitis (pinkeye; infection ... follow these steps: Wash your hands thoroughly with soap and water. While tilting your head back, pull ...

  14. An Insight into Ophthalmic Drug Delivery System

    OpenAIRE

    Rathore K. S.; Nema R. K.

    2009-01-01

    Promising management of eye ailments take off effective concentration of drug at the eye for sufficient period of time. Dosage forms are administered directly to eye for localized ophthalmic therapy. Most of the treatments call for the topical administration of ophthalmic active drugs to the tissues around the ocular cavity. Conventional ophthalmic drug delivery systems including eye drops, ophthalmic ointments, are no longer sufficient to encounter eye diseases. This article reviews the cons...

  15. 21 CFR 349.18 - Ophthalmic vasoconstrictors.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 5 2010-04-01 2010-04-01 false Ophthalmic vasoconstrictors. 349.18 Section 349.18... FOR HUMAN USE OPHTHALMIC DRUG PRODUCTS FOR OVER-THE-COUNTER HUMAN USE Active Ingredients § 349.18 Ophthalmic vasoconstrictors. The active ingredient of the product consists of one of the following,...

  16. Once a day ocular inserts for sustained delivery of levofloxacin: Design, formulation and evaluation

    Directory of Open Access Journals (Sweden)

    Gevariya Hitesh

    2009-01-01

    Full Text Available Levofloxacin is a fluoroquinolone antibacterial drug effective in the treatment of bacterial conjunctivitis. The objective of the present work was to develop ocular inserts of levofloxacin and evaluate their potential for sustained ocular delivery. Conventional ophthalmic solution shows the poor bioavailability and therapeutic response due to many pre - corneal constraints. These constrains necessitate the controlled and sustained drug delivery to become a standard one in the modern pharmaceutical era. Matrix-type ocular inserts were prepared by the film-casting technique in Teflon-coated Petri dishes and characterized in vitro by drug release studies using a flow-through apparatus that simulated the eye conditions. Nine formulations were developed, which differed in the ratio of polymers polyethylene oxide (PEO, hydroxypropyl cellulose (HPC and ethyl cellulose (EC. All the formulations were subjected to evaluation of thickness, weight variation, folding endurance and drug content uniformity and in vitro release study. On the basis of in vitro drug release studies, the formulation with PEO/EC (F9 was found to be better than the other formulations (release of 101.35% within 24 hrs and it was selected as an optimized formulation, which was further subjected to in vivo studies and ageing studies. The in vitro result revealed that formulation F9 followed a perfect zero-order kinetics release (n = 1.03 and the rest of the formulations released the drug by super case II kinetics (n > 1. It was also observed that increasing the proportion of PEO and HPC to EC increases the rate of release of Levofloxacin. On the basis of in vitro and in vivo correlation stability studies, it can be concluded that this ocular inserts formulation can be a promising once-a-day controlled release formulation.

  17. 21 CFR 886.4855 - Ophthalmic instrument table.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic instrument table. 886.4855 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4855 Ophthalmic instrument table. (a) Identification. An ophthalmic instrument table is an AC-powered or manual device on which ophthalmic...

  18. 21 CFR 886.4230 - Ophthalmic knife test drum.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic knife test drum. 886.4230 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4230 Ophthalmic knife test drum. (a) Identification. An ophthalmic knife test drum is a device intended to test the keenness of ophthalmic...

  19. Ophthalmic halo reduced lenses design

    Science.gov (United States)

    Limon, Ofer; Zalevsky, Zeev

    2015-05-01

    The halo effect is a very problematic visual artifact occurring in extended depth of focus or multi-focal ophthalmic lenses such as e.g. intra-ocular (after cataract surgery) or contact lenses when used in dark illumination conditions. This artifact is generated due to surface structures added on top of those lenses in order to increase their depth of focus or to realize multiple focal lengths. In this paper we present novel solution that can resolve this major problem of ophthalmic lenses. The proposed solution involves modification to the surface structure that realizes the extended depth of focus. Our solution is fabricated and numerically and experimentally validated also in preliminary in-vivo trials.

  20. Potential bias in ophthalmic pharmaceutical clinical trials

    OpenAIRE

    Paul Varner

    2008-01-01

    Paul VarnerJohn J Pershing Veterans’ Administration Medical Center, Poplar Bluff, Missouri, USAAbstract: To make clinicians aware of potential sources of error in ophthalmic pharmaceutical clinical trials that can lead to erroneous interpretation of results, a critical review of the study design of various pharmaceutical ophthalmic clinical trials was completed. Discrepancies as a result of study shortcomings may explain observed differences between reported ophthalmic trial data an...

  1. 75 FR 54492 - Ophthalmic and Topical Dosage Form New Animal Drugs; Gentamicin and Betamethasone Ophthalmic...

    Science.gov (United States)

    2010-09-08

    ... HUMAN SERVICES Food and Drug Administration 21 CFR Part 524 Ophthalmic and Topical Dosage Form New Animal Drugs; Gentamicin and Betamethasone Ophthalmic Solution AGENCY: Food and Drug Administration, HHS...) for gentamicin sulfate and betamethasone acetate ophthalmic solution. This action is being taken...

  2. Ophthalmic findings in dyslexic schoolchildren.

    OpenAIRE

    Latvala, M L; Korhonen, T T; Penttinen, M.; Laippala, P.

    1994-01-01

    The ophthalmic findings of 55 dyslexic 12 to 13-year-old Finnish schoolchildren and 50 age, sex, and social class-matched control children were evaluated. On a neuropsychological basis the children could be divided into six subgroups: general deficiency, general language, visuomotor, naming, mixed, and normal. The two groups did not differ significantly from each other in visual acuity, cycloplegic refraction, the amount of phorias and tropias, stereo acuity, fusion, or accommodation. Converg...

  3. Current uses of ophthalmic lasers.

    OpenAIRE

    O'Neill, D; GREGSON, R; McHugh, D

    1992-01-01

    Current laser treatments are quick, relatively painless, and well tolerated. Some ophthalmic techniques can be performed only by laser while others have a lower morbidity than alternative treatments. Peripheral retinal photocoagulation and focal photocoagulation now offer greatly improved visual prognosis for diabetic patients with proliferative diabetic retinopathy or diabetic macular disease. Selected cases of macular degeneration may be treated by focal laser photocoagulation. The role of ...

  4. Calorimeter insertion

    CERN Multimedia

    2006-01-01

    Calorimeter insertion between toroids in the ATLAS experiment detector Calorimeters are surrounding the inner detector. Calorimeters will absorb and measure the energies of the most charged and neutral particles after the collisions. The saved energy in the calorimeter is detected and converted to signals that are taken out with data taking electronics.

  5. 21 CFR 349.10 - Ophthalmic astringent.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 5 2010-04-01 2010-04-01 false Ophthalmic astringent. 349.10 Section 349.10 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS FOR HUMAN USE OPHTHALMIC DRUG PRODUCTS FOR OVER-THE-COUNTER HUMAN USE Active Ingredients § 349.10...

  6. 21 CFR 349.12 - Ophthalmic demulcents.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 5 2010-04-01 2010-04-01 false Ophthalmic demulcents. 349.12 Section 349.12 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS FOR HUMAN USE OPHTHALMIC DRUG PRODUCTS FOR OVER-THE-COUNTER HUMAN USE Active Ingredients § 349.12...

  7. Wettability measurement of materials for ophthalmic applications

    International Nuclear Information System (INIS)

    The wettability properties of materials for ophthalmic applications have been investigated through the contact angle technique. Measurements have been carried out on ophthalmic lenses with differing optical power but coated with the same multilayer or with differing multilayer treatments but equal optical power, under different cleaning conditions. Contact lenses of differing materials, both gaspermeable and soft, were also tested in vitro.

  8. 21 CFR 349.14 - Ophthalmic emollients.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 5 2010-04-01 2010-04-01 false Ophthalmic emollients. 349.14 Section 349.14 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS FOR HUMAN USE OPHTHALMIC DRUG PRODUCTS FOR OVER-THE-COUNTER HUMAN USE Active Ingredients § 349.14...

  9. Cellulose is not just cellulose

    DEFF Research Database (Denmark)

    Hidayat, Budi Juliman; Felby, Claus; Johansen, Katja S.;

    2012-01-01

    Most secondary plant cell walls contain irregular regions known as dislocations or slip planes. Under industrial biorefining conditions dislocations have recently been shown to play a key role during the initial phase of the enzymatic hydrolysis of cellulose in plant cell walls. In this review we...... not regions where free cellulose ends are more abundant than in the bulk cell wall. In more severe cases cracks between fibrils form at dislocations and it is possible that the increased accessibility that these cracks give is the reason why hydrolysis of cellulose starts at these locations. If acid...

  10. Insertion sequences.

    OpenAIRE

    Mahillon, Jacques; Chandler, M.

    1998-01-01

    Insertion sequences (ISs) constitute an important component of most bacterial genomes. Over 500 individual ISs have been described in the literature to date, and many more are being discovered in the ongoing prokaryotic and eukaryotic genome-sequencing projects. The last 10 years have also seen some striking advances in our understanding of the transposition process itself. Not least of these has been the development of various in vitro transposition systems for both prokaryotic and eukaryoti...

  11. 21 CFR 886.1405 - Ophthalmic trial lens set.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic trial lens set. 886.1405 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1405 Ophthalmic trial lens set. (a) Identification. An ophthalmic trial lens set is a device that is a set of lenses of various dioptric...

  12. 21 CFR 886.1655 - Ophthalmic Fresnel prism.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic Fresnel prism. 886.1655 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1655 Ophthalmic Fresnel prism. (a) Identification. An ophthalmic Fresnel prism is a device that is a thin plastic sheet with embossed rulings...

  13. 21 CFR 886.5800 - Ophthalmic bar reader.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic bar reader. 886.5800 Section 886.5800...) MEDICAL DEVICES OPHTHALMIC DEVICES Therapeutic Devices § 886.5800 Ophthalmic bar reader. (a) Identification. An ophthalmic bar reader is a device that consists of a magnifying lens intended for use by...

  14. 21 CFR 886.3100 - Ophthalmic tantalum clip.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic tantalum clip. 886.3100 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Prosthetic Devices § 886.3100 Ophthalmic tantalum clip. (a) Identification. An ophthalmic tantalum clip is a malleable metallic device intended to be implanted...

  15. 21 CFR 886.1665 - Ophthalmic rotary prism.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic rotary prism. 886.1665 Section 886.1665...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1665 Ophthalmic rotary prism. (a) Identification. An ophthalmic rotary prism is a device with various prismatic powers intended to be handheld...

  16. 21 CFR 886.5100 - Ophthalmic beta radiation source.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic beta radiation source. 886.5100 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Therapeutic Devices § 886.5100 Ophthalmic beta radiation source. (a) Identification. An ophthalmic beta radiation source is a device intended to apply...

  17. 21 CFR 886.4250 - Ophthalmic electrolysis unit.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic electrolysis unit. 886.4250 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4250 Ophthalmic electrolysis unit. (a) Identification. An ophthalmic electrolysis unit is an AC-powered or battery-powered device intended to...

  18. 21 CFR 886.4750 - Ophthalmic eye shield.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic eye shield. 886.4750 Section 886.4750...) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4750 Ophthalmic eye shield. (a) Identification. An ophthalmic eye shield is a device that consists of a plastic or aluminum eye covering intended...

  19. 21 CFR 886.4770 - Ophthalmic operating spectacles (loupes).

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic operating spectacles (loupes). 886.4770... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4770 Ophthalmic operating spectacles (loupes). (a) Identification. Ophthalmic operating spectacles (loupes) are devices that consist of...

  20. 21 CFR 886.1650 - Ophthalmic bar prism.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic bar prism. 886.1650 Section 886.1650...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1650 Ophthalmic bar prism. (a) Identification. An ophthalmic bar prism is a device that is a bar composed of fused prisms of gradually...

  1. 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...

  2. 21 CFR 886.5810 - Ophthalmic prism reader.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic prism reader. 886.5810 Section 886.5810...) MEDICAL DEVICES OPHTHALMIC DEVICES Therapeutic Devices § 886.5810 Ophthalmic prism reader. (a) Identification. An ophthalmic prism reader is a device intended for use by a patient who is in a supine...

  3. 21 CFR 886.1670 - Ophthalmic isotope uptake probe.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic isotope uptake probe. 886.1670 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1670 Ophthalmic isotope uptake probe. (a) Identification. An ophthalmic isotope uptake probe is an AC-powered device intended to...

  4. 21 CFR 886.1410 - Ophthalmic trial lens clip.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic trial lens clip. 886.1410 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1410 Ophthalmic trial lens clip. (a) Identification. An ophthalmic trial lens clip is a device intended to hold prisms, spheres, cylinders,...

  5. 21 CFR 886.1860 - Ophthalmic instrument stand.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic instrument stand. 886.1860 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1860 Ophthalmic instrument stand. (a) Identification. An ophthalmic instrument stand is an AC-powered or nonpowered device intended to store...

  6. 21 CFR 886.4570 - Ophthalmic surgical marker.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic surgical marker. 886.4570 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4570 Ophthalmic surgical marker. (a) Identification. An ophthalmic surgical marker is a device intended to mark by use of ink, dye, or indentation...

  7. Oncocytic lesions of the ophthalmic region

    DEFF Research Database (Denmark)

    Østergaard, Jens; Prause, Jan U; Heegaard, Steffen

    2011-01-01

    Purpose: This study aimed to make a nationwide clinicopathological study of oncocytic lesions in the ophthalmic region and to characterize their cytokeratin (CK) expression. Methods: All histologically diagnosed oncocytic lesions in the ophthalmic region registered in Denmark over a 25-year period...... expression. Basal-type oncocytic cells reacted with antibodies against CK 5/6, CK 7, CK 8, CK 13, CK 14, CK 17, CK 18 and CK 19, and suprabasal cells with CK 4, CK 7, CK 8, CK 18 and CK 19. Antibodies against CK 1+10 and CK 20 showed no reaction. Conclusions: Oncocytic lesions of the ophthalmic region most...

  8. Transcutaneous Puncture of the Superior Ophthalmic Vein for Embolization of Dural Carotid-Ophthalmic Fistula

    OpenAIRE

    Chen, Wen-Hsien; Tsai, I-Chen; Huang, Hou-Chi; Lin, Chun-Han; Hung, Hao-Chun; Wu, Chen-Hao; Chi-Chang Chen, Clayton

    2008-01-01

    Carotid-ophthalmic fistula is a rare disease, which can be treated by transvenous endovascular embolization. Here, we report a unique case with draining vein thrombosed, making a transvenous approach impossible. An old but valuable technique, direct transcutaneous puncture of the superior ophthalmic vein, was used to save the patient's right eye. The old technique, direct puncture of the superior ophthalmic vein, retains its irreplaceable usefulness in this special situation. Thus, interventi...

  9. Ocular inserts - Advancement in therapy of eye diseases

    Directory of Open Access Journals (Sweden)

    Anita Kumari

    2010-01-01

    Full Text Available The ocular insert represents a significant advancement in the therapy of eye disease. Ocular inserts are defined as sterile, thin, multilayered, drug-impregnated, solid or semisolid consistency devices placed into the cul-de-sac or conjuctival sac, whose size and shape are especially designed for ophthalmic application. They are composed of a polymeric support that may or may not contain a drug. The drug can later be incorporated as dispersion or a solution in the polymeric support. They offer several advantages as increased ocular residence and sustained release of medication into the eye. The insert includes a body portion sized to position within a lachrymal canaliculus of the eyelid. The inserts are classified according to their solubility as insoluble, soluble, or bioerodible inserts. The release of drug from the insert depends upon the diffusion, osmosis, and bioerosion of the drug, and this article is an attempt to present a brief about this newer drug delivery system.

  10. Big data and ophthalmic research.

    Science.gov (United States)

    Clark, Antony; Ng, Jonathon Q; Morlet, Nigel; Semmens, James B

    2016-01-01

    Large population-based health administrative databases, clinical registries, and data linkage systems are a rapidly expanding resource for health research. Ophthalmic research has benefited from the use of these databases in expanding the breadth of knowledge in areas such as disease surveillance, disease etiology, health services utilization, and health outcomes. Furthermore, the quantity of data available for research has increased exponentially in recent times, particularly as e-health initiatives come online in health systems across the globe. We review some big data concepts, the databases and data linkage systems used in eye research-including their advantages and limitations, the types of studies previously undertaken, and the future direction for big data in eye research. PMID:26844660

  11. Ophthalmic regional blocks: management, challenges, and solutions

    OpenAIRE

    Palte HD

    2015-01-01

    Howard D Palte Department of Anesthesiology, Perioperative Medicine and Pain Management, Miller School of Medicine, University of Miami, Miami, FL, USA Abstract: In the past decade ophthalmic anesthesia has witnessed a major transformation. The sun has set on the landscape of ophthalmic procedures performed under general anesthesia at in-hospital settings. In its place a new dawn has ushered in the panorama of eye surgeries conducted under regional and topical anesthesia at specialty eye car...

  12. Ophthalmic parameters in adult Shih Tzu dogs

    OpenAIRE

    Karina Kamachi Kobashigawa; Tiago Barbalho Lima; Ivan Ricardo Martinez Padua; Alexandre Augusto Franchi de Barros Sobrinho; Fabio de Andrade Marinho; Kethye Priscila Ortêncio; José Luiz Laus

    2015-01-01

    Ocular surface diseases are often diagnosed in brachycephalic dogs. The ophthalmic parameters of the Shih Tzu dogs are evaluated in this study since this breed is among the most commonly affected by these diseases. In this study, ophthalmic parameters of this breed were partly studied under physical restraint. Schirmer tear test, breakup time test, aesthesiometry, biomicroscopy, non-contact specular microscopy, laser flaremetry, applanation tonometry, ultrasonography and ophthalmoscopy were c...

  13. Isolation and characterization of two cellulose morphology mutants of Gluconacetobacter hansenii ATCC23769 producing cellulose with lower crystallinity.

    Science.gov (United States)

    Deng, Ying; Nagachar, Nivedita; Fang, Lin; Luan, Xin; Catchmark, Jeffrey M; Tien, Ming; Kao, Teh-hui

    2015-01-01

    Gluconacetobacter hansenii, a Gram-negative bacterium, produces and secrets highly crystalline cellulose into growth medium, and has long been used as a model system for studying cellulose synthesis in higher plants. Cellulose synthesis involves the formation of β-1,4 glucan chains via the polymerization of glucose units by a multi-enzyme cellulose synthase complex (CSC). These glucan chains assemble into ordered structures including crystalline microfibrils. AcsA is the catalytic subunit of the cellulose synthase enzymes in the CSC, and AcsC is required for the secretion of cellulose. However, little is known about other proteins required for the assembly of crystalline cellulose. To address this question, we visually examined cellulose pellicles formed in growth media of 763 individual colonies of G. hansenii generated via Tn5 transposon insertion mutagenesis, and identified 85 that produced cellulose with altered morphologies. X-ray diffraction analysis of these 85 mutants identified two that produced cellulose with significantly lower crystallinity than wild type. The gene disrupted in one of these two mutants encoded a lysine decarboxylase and that in the other encoded an alanine racemase. Solid-state NMR analysis revealed that cellulose produced by these two mutants contained increased amounts of non-crystalline cellulose and monosaccharides associated with non-cellulosic polysaccharides as compared to the wild type. Monosaccharide analysis detected higher percentages of galactose and mannose in cellulose produced by both mutants. Field emission scanning electron microscopy showed that cellulose produced by the mutants was unevenly distributed, with some regions appearing to contain deposition of non-cellulosic polysaccharides; however, the width of the ribbon was comparable to that of normal cellulose. As both lysine decarboxylase and alanine racemase are required for the integrity of peptidoglycan, we propose a model for the role of peptidoglycan in the

  14. Isolation and characterization of two cellulose morphology mutants of Gluconacetobacter hansenii ATCC23769 producing cellulose with lower crystallinity.

    Directory of Open Access Journals (Sweden)

    Ying Deng

    Full Text Available Gluconacetobacter hansenii, a Gram-negative bacterium, produces and secrets highly crystalline cellulose into growth medium, and has long been used as a model system for studying cellulose synthesis in higher plants. Cellulose synthesis involves the formation of β-1,4 glucan chains via the polymerization of glucose units by a multi-enzyme cellulose synthase complex (CSC. These glucan chains assemble into ordered structures including crystalline microfibrils. AcsA is the catalytic subunit of the cellulose synthase enzymes in the CSC, and AcsC is required for the secretion of cellulose. However, little is known about other proteins required for the assembly of crystalline cellulose. To address this question, we visually examined cellulose pellicles formed in growth media of 763 individual colonies of G. hansenii generated via Tn5 transposon insertion mutagenesis, and identified 85 that produced cellulose with altered morphologies. X-ray diffraction analysis of these 85 mutants identified two that produced cellulose with significantly lower crystallinity than wild type. The gene disrupted in one of these two mutants encoded a lysine decarboxylase and that in the other encoded an alanine racemase. Solid-state NMR analysis revealed that cellulose produced by these two mutants contained increased amounts of non-crystalline cellulose and monosaccharides associated with non-cellulosic polysaccharides as compared to the wild type. Monosaccharide analysis detected higher percentages of galactose and mannose in cellulose produced by both mutants. Field emission scanning electron microscopy showed that cellulose produced by the mutants was unevenly distributed, with some regions appearing to contain deposition of non-cellulosic polysaccharides; however, the width of the ribbon was comparable to that of normal cellulose. As both lysine decarboxylase and alanine racemase are required for the integrity of peptidoglycan, we propose a model for the role of

  15. Cellulose microfibril deposition: coordinated activity at the plant plasma membrane

    NARCIS (Netherlands)

    Lindeboom, J.J.; Mulder, B.; Vos, J.W.; Ketelaar, M.J.; Emons, A.M.C.

    2008-01-01

    Plant cell wall production is a membrane-bound process. Cell walls are composed of cellulose microfibrils, embedded inside a matrix of other polysaccharides and glycoproteins. The cell wall matrix is extruded into the existing cell wall by exocytosis. This same process also inserts the cellulose syn

  16. 21 CFR 524.390a - Chloramphenicol ophthalmic ointment.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Chloramphenicol ophthalmic ointment. 524.390a... (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS OPHTHALMIC AND TOPICAL DOSAGE FORM NEW ANIMAL DRUGS § 524.390a Chloramphenicol ophthalmic ointment. (a) Specifications. Each gram contains 10...

  17. 21 CFR 524.1044a - Gentamicin ophthalmic solution.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Gentamicin ophthalmic solution. 524.1044a Section... (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS OPHTHALMIC AND TOPICAL DOSAGE FORM NEW ANIMAL DRUGS § 524.1044a Gentamicin ophthalmic solution. (a) Specifications. Each milliliter of sterile...

  18. 21 CFR 349.50 - Labeling of ophthalmic drug products.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 5 2010-04-01 2010-04-01 false Labeling of ophthalmic drug products. 349.50... (CONTINUED) DRUGS FOR HUMAN USE OPHTHALMIC DRUG PRODUCTS FOR OVER-THE-COUNTER HUMAN USE Labeling § 349.50 Labeling of ophthalmic drug products. (a) The word “physician” may be substituted for the word “doctor”...

  19. 21 CFR 524.1484a - Neomycin sulfate ophthalmic ointment.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Neomycin sulfate ophthalmic ointment. 524.1484a... (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS OPHTHALMIC AND TOPICAL DOSAGE FORM NEW ANIMAL DRUGS § 524.1484a Neomycin sulfate ophthalmic ointment. (a) Specifications. Each gram of the ointment...

  20. 21 CFR 524.575 - Cyclosporine ophthalmic ointment.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Cyclosporine ophthalmic ointment. 524.575 Section... (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS OPHTHALMIC AND TOPICAL DOSAGE FORM NEW ANIMAL DRUGS § 524.575 Cyclosporine ophthalmic ointment. (a) Specifications. Each gram of ointment contains...

  1. 21 CFR 524.1200a - Kanamycin ophthalmic ointment.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Kanamycin ophthalmic ointment. 524.1200a Section... (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS OPHTHALMIC AND TOPICAL DOSAGE FORM NEW ANIMAL DRUGS § 524.1200a Kanamycin ophthalmic ointment. (a) Specifications. The drug, which is in a suitable...

  2. 21 CFR 524.1044c - Gentamicin sulfate ophthalmic ointment.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Gentamicin sulfate ophthalmic ointment. 524.1044c... (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS OPHTHALMIC AND TOPICAL DOSAGE FORM NEW ANIMAL DRUGS § 524.1044c Gentamicin sulfate ophthalmic ointment. (a) Specifications. Each gram of ointment...

  3. 21 CFR 524.1982 - Proparacaine hydrochloride ophthalmic solution.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Proparacaine hydrochloride ophthalmic solution... SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS OPHTHALMIC AND TOPICAL DOSAGE FORM NEW ANIMAL DRUGS § 524.1982 Proparacaine hydrochloride ophthalmic solution. (a) Specifications. The drug...

  4. 21 CFR 349.16 - Ophthalmic hypertonicity agent.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 5 2010-04-01 2010-04-01 false Ophthalmic hypertonicity agent. 349.16 Section 349...) DRUGS FOR HUMAN USE OPHTHALMIC DRUG PRODUCTS FOR OVER-THE-COUNTER HUMAN USE Active Ingredients § 349.16 Ophthalmic hypertonicity agent. The active ingredient and its concentration in the product is as...

  5. 21 CFR 200.50 - Ophthalmic preparations and dispensers.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Ophthalmic preparations and dispensers. 200.50... (CONTINUED) DRUGS: GENERAL GENERAL Requirements for Specific Classes of Drugs § 200.50 Ophthalmic... intended for ophthalmic use, including preparations for cleansing the eyes, should be sterile. It...

  6. 21 CFR 886.1415 - Ophthalmic trial lens frame.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic trial lens frame. 886.1415 Section 886.1415 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1415 Ophthalmic trial lens frame....

  7. 21 CFR 524.390b - Chloramphenicol ophthalmic solution.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Chloramphenicol ophthalmic solution. 524.390b... (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS OPHTHALMIC AND TOPICAL DOSAGE FORM NEW ANIMAL DRUGS § 524.390b Chloramphenicol ophthalmic solution. (a) Specifications. Each milliliter contains...

  8. Ophthalmic masquerades of the atherosclerotic carotids

    Directory of Open Access Journals (Sweden)

    Anupriya Arthur

    2014-01-01

    Full Text Available Patients with carotid atherosclerosis can present with ophthalmic symptoms. These symptoms and signs can be due to retinal emboli, hypoperfusion of the retina and choroid, opening up of collateral channels, or chronic hypoperfusion of the globe (ocular ischemic syndrome. These pathological mechanisms can produce many interesting signs and a careful history can bring out important past symptoms pointing toward the carotid as the source of the patient′s presenting symptom. Such patients are at high risk for an ischemic stroke, especially in the subsequent few days following their first acute symptom. It is important for clinicians to be familiar with these ophthalmic symptoms and signs caused by carotid atherosclerosis for making an early diagnosis and to take appropriate measures to prevent a stroke. This review elaborates the clinical features, importance, and implications of various ophthalmic symptoms and signs resulting from atherosclerotic carotid artery disease.

  9. Calibration of Sr-90 ophthalmic applicators

    International Nuclear Information System (INIS)

    The purpose of this paper is to alert users of Sr-90 ophthalmic applicators about potential large errors in calibration of these devices. A discrepancy of more than 50% in calibration of Sr-90 ophthalmic applicators between the US National Institute of Standards and Technology (NIST) and one foreign manufacturer (the world's only remaining supplier) has been reported. A single-plane Sr-90 ophthalmic applicator was calibrated by the manufacturer, by NIST, and by the University of Wisconsin. The manufacturer's close rate calibration is confined to a 3-mm-diameter active area, while NIST measures all beta radiation emitted into a 2-PI solid angle. The discrepancy was verified by means of a technique based on that of NIST. Reports of calibrations at NIST of applicators made by several American manufacturers (no longer available) indicate that large discrepancies exist for other manufacturers as well

  10. Naturally occurring radioactivity in ophthalmic glass

    International Nuclear Information System (INIS)

    The manufacture of ophthalmic glass frequently utilizes mixtures of rare earths and zirconium oxides, which contain low levels of alpha-emitting decay products of natural thorium and uranium. Because of a concern about the possible effects of alpha irradiation of the cornea of the eye, the US Atomic Energy Commission in 1974 conducted a survey to determine the nature and quantity of radioactivity that might be present in ophthalmic glass in the United states and reviewed the pertinent dosimetry and radiobiologic significance related to the use of such glass. This report summarizes the salient features of the dosimetry used, briefly discusses the pertinent radiobiology, presents the results of analyses of 441 glass samples, and describes the industry ophthalmic glass radiological standard, issued voluntarily by the industry on November 1, 1975

  11. 新型组织工程材料细菌纤维素在眼科等医学领域的研究与应用%The research progress in bacterial cellulose and its application as new tissue engineering material in ophthalmic and other medical fields

    Institute of Scientific and Technical Information of China (English)

    李京

    2013-01-01

    Bacterial cellulose iunique and promising material aimplantand scaffoldin tissue engineering study.Iicomposed of pure cellulose nanofibemesh spun by bacteria.Aithigh watecontenand purity,iimore biocompatible fomultiple medical applications.In addition,iieasy to control itmechanical strength,chemical structure and morphology,therefore iimore suitable to be used abiomedical material in vivo.Bacterial cellulose habeen applied atissue engineering material in clinical medical aspects,foexample,wound dressingalternatives,artificial skin,artery eluting stent,bone tissue engineering scaffold,artificial blood vessel,artificial hearvalve prosthesis.The application of bacterial cellulose ialso extended to the construction of tissue engineering corneal stromand corneal contaclens.Thipapereviewthe progresin the applying spectrum of bacterial cellulose in corneal tissue engineering and othemedical field.%细菌纤维素(BC)是一种独特的具有应用前景的组织工程支架材料,由细菌产生的纳米纯纤维网状结构组成.BC具有强度大及含水量高的优点,具有更好的生物相容性,BC的机械强度、化学特性和形态学具有可控性,更适用于作为体内的生物材料.BC已广泛应用于生物医学领域,包括作为局部携带药物的伤口敷料替代品,在神经外科用于人工皮肤的覆盖和硬脑膜修补术以及动脉涂层支架,在骨科用于骨组织工程支架,在显微外科作为人工血管构建,在心血管外科用于人工心脏瓣膜的构建等,此外,BC的用途也已扩展到眼科领域组织工程化角膜基质的构建和角膜接触镜的生产.就BC在组织工程角膜及其他医学领域的应用进行综述.

  12. Topical ophthalmic NSAIDs: a discussion with focus on nepafenac ophthalmic suspension

    OpenAIRE

    Bruce I Gaynes; Anne Onyekwuluje

    2008-01-01

    Bruce I Gaynes1,2, Anne Onyekwuluje11Departments of Ophthalmology and 2Pharmacology, Rush College of Medicine, Chicago, Illinois, USAAbstract: The removal of diclofenac sodium ophthalmic solution as a viable pharmaceutical entity in September 1999 from the US market spurred considerable interest in the general safety and effectiveness of topical ophthalmic NSAIDs for treatment of anterior segment inflammation. In late 1999 the use of topical ocular NSAIDs declined in the US as a result of inc...

  13. Dural AVM supplied by the ophthalmic artery.

    LENUS (Irish Health Repository)

    Flynn, T H

    2012-02-03

    Dural arteriovenous malformations in the anterior cranial fossa are rare and are especially prone to haemorrhage. These lesions are usually treated by surgical excision. We report the embolization of an anterior cranial fossa DAVM using an endovascular approach via the ophthalmic artery.

  14. Ophthalmic implications of seasonal affective disorder

    International Nuclear Information System (INIS)

    A review of seasonal affective disorder (SAD) is presented with a discussion of its standard treatment of phototherapy. A number of ophthalmic implications related to SAD are proposed. These implications relate to both the condition and the phototherapy used in its treatment, especially the use of full spectrum light which contains ultraviolet and near ultraviolet radiation. 12 references

  15. Cellulose based conductive polymers

    OpenAIRE

    Lin, Haishu

    2015-01-01

    Conductive fibers show potential applications in different areas. In this thesis, cellulose and its derivatives, including carboxymethyl cellulose, cellulose acetate as well as methyl cellulose were used to produce fibers via wet spinning. Different conductive materials were also introduced in an attempt to obtain cellulose-derived conductive fibers. Different conductive fillers (Zelec, carbon black, conductive polymers) were evaluated. Among them, PEDOT and PPy conductive polymers showed...

  16. AN OPHTHALMIC HEALTH SURVEY IN NORTHERN IRAN

    Directory of Open Access Journals (Sweden)

    Kh. Moradpour

    1974-06-01

    Full Text Available The province of Rudsar is located in the Caspian littoral zone of Iran. In 1970 an ophthalmic health survey was carried out in 25 units, which were selected by random sampling in these areas. A total of 2,165 persons were examined and the results of this evaluation have been prepared in 6 parts, consisting of ophthalmic conditions and health customs, infectious eye diseases, visual status and diseases, blindness and its causes, eye complications of malnutrition, and other eye disease. The prevalence of trachoma is 24% and of conjunctivitis 11.2%, but infectious eye diseases are mild in these areas and their complications are very rare, and trachoma is deviated mainly to inclusion conjunctivitis. Visual defect are important problem in the Rudsar area; 17.8% of the persons examined of 10 years of age and over, had visual defects. The most important causes of visual defects are refraction abnor­malities, especially myopic astigmatism and contact. Visual defects are more prevalent in females than in males. Of the total number of persons examined, 2.63% had infectious eye diseases, 2.77% had blindness in at least one eye and 56.7% of the blindness was caused by cataracts. The eye complications of avitaminosis A and ariboflavinosis were observed, especially in rural areas. The establish­ment of an ophthalmic clinic, the use of a mobile dispensary unit for diagnosis, procedures for introducing patients to the ophthalmic clinic, and special procedures for the health of school children would be beneficial and are recommended for the control of ophthalmic disease. It is also necessary to have a special survey on toxoplasmosis, an investigation for clarification of the causes of differences in visual defects in males and females, and a survey on the causes of blepharitis.

  17. Metallization of bacterial cellulose for electrical and electronic device manufacture

    Energy Technology Data Exchange (ETDEWEB)

    Evans, Barbara R [Oak Ridge, TN; O' Neill, Hugh M [Knoxville, TN; Jansen, Valerie Malyvanh [Memphis, TN; Woodward, Jonathan [Knoxville, TN

    2010-09-28

    A method for the deposition of metals in bacterial cellulose and for the employment of the metallized bacterial cellulose in the construction of fuel cells and other electronic devices is disclosed. The method for impregnating bacterial cellulose with a metal comprises placing a bacterial cellulose matrix in a solution of a metal salt such that the metal salt is reduced to metallic form and the metal precipitates in or on the matrix. The method for the construction of a fuel cell comprises placing a hydrated bacterial cellulose support structure in a solution of a metal salt such that the metal precipitates in or on the support structure, inserting contact wires into two pieces of the metal impregnated support structure, placing the two pieces of metal impregnated support structure on opposite sides of a layer of hydrated bacterial cellulose, and dehydrating the three layer structure to create a fuel cell.

  18. Metallization of bacterial cellulose for electrical and electronic device manufacture

    Energy Technology Data Exchange (ETDEWEB)

    Evans, Barbara R. (Oak Ridge, TN); O' Neill, Hugh M. (Knoxville, TN); Jansen, Valerie Malyvanh (Memphis, TN); Woodward, Jonathan (Knoxville, TN)

    2011-06-07

    A method for the deposition of metals in bacterial cellulose and for the employment of the metallized bacterial cellulose in the construction of fuel cells and other electronic devices is disclosed. The method for impregnating bacterial cellulose with a metal comprises placing a bacterial cellulose matrix in a solution of a metal salt such that the metal salt is reduced to metallic form and the metal precipitates in or on the matrix. The method for the construction of a fuel cell comprises placing a hydrated bacterial cellulose support structure in a solution of a metal salt such that the metal precipitates in or on the support structure, inserting contact wires into two pieces of the metal impregnated support structure, placing the two pieces of metal impregnated support structure on opposite sides of a layer of hydrated bacterial cellulose, and dehydrating the three layer structure to create a fuel cell.

  19. Shortcomings of the industrial quality assurance of 106Ru ophthalmic plaques

    International Nuclear Information System (INIS)

    Background: Beta emitting 106Ru applicators manufactured by Bebig GmbH (Berlin, Germany) are widely used to treat intraocular tumors. The applicators are fixed to the bulbus and removed after several days. The following therapy relevant defects have been detected by an internal clinical acceptance test: risk of leakage and inconsistent dose-rate specifications by the manufacturer. In the meantime, components of the internal clinical acceptance test have been adopted successfully by the manufacturer of the 106Ru ophthalmic plaques. Material and Method: 106Ru ophthalmic plaques were tested with the following internal clinical acceptance tests: visual inspection, surface contamination, leakage, and dose-rate verification. The surface contamination test consists of a wet wipe test at moderate pressure. For the leakage test of the 106Ru ophthalmic plaques a clinically relevant scenario was developed in which the contact of the applicator with human tissue is simulated. In the course of it the applicator is inserted into Ringer's solution for several days. The certified energy dose-rate statements of the manufacturer are examined with a 1 mm3 plastic scintillator for consistency. (orig.)

  20. Are we pharmacovigilant enough in ophthalmic practice?

    Directory of Open Access Journals (Sweden)

    Ashok Dubey

    2013-01-01

    Full Text Available No drug is absolutely safe. Pharmacovigilance is the science related to detection, assessment, understanding and prevention of adverse effects or any other possible drug-related problems. The ocular medications and devices can cause localized and systemic adverse effects. Not all adverse effects are known when a drug or device is launched in market because of limitations of clinical trials. Many adverse effects are recognized due to the spontaneous reporting of the vigilant doctors who observe and report such events encountered in their practice. Despite a large ophthalmic patient population base, India does not have robust adverse drug reaction (ADR database because of lack of reporting culture. Government of India recently launched the Pharmacovigilance Programme of India (PvPI to monitor ADRs and create awareness among the healthcare professionals about the importance of ADRs. Suspecting and reporting a possible drug reaction is very important in developing a safe and rational ophthalmic practice.

  1. A new kind of monitor for ophthalmic operation

    International Nuclear Information System (INIS)

    The integrity of the vision channel is often checked using VEP in order to avoiding damaging important tissue during an ophthalmic operation. But the measurement of before operations has strong side effects, it may damage the eyeball. We will introduce a new kind for monitoring ophthalmic operations in this paper. It uses visual electrical evoked potential to check the integrity of the vision access and it can monitor ophthalmic operations and avoid damaging any tissue, so it ensures the safety of the operation

  2. Medical physics aspects of ophthalmic brachytherapy

    International Nuclear Information System (INIS)

    Intraocular melanoma is the most common primary malignancy of the eye. Radiation therapy using ophthalmic plaque has proved successful in the management of various ocular lesions. Although a few centres were using 90Sr/90Y plaques for shallow turtlours some years ago, eye plaque therapy was not a common practice in India. A revived interest in the use of eye plaque therapy and very high cost of imported sources has led to the development and production of 125I seed sources by the Radiopharmaceuticals Division, BARC. This report presents a brief description on the clinical, dosimetry and radiation safety aspects of 90Sr/90Y and 106Ru/106Rh beta ray and 125I gamma ray eye plaque applicators. This report has been divided in five Sections. Section I presents general introduction of ophthalmic brachytherapy including the structure of a human eye, types of ophthalmic plaques and characteristics of radioisotopes commonly used in such applications. A brief review of sources, applicators and dosimetry of 90Sr/90Y and 106Ru/106Rh beta and 125I gamma ophthalmic plaques are given in Section II and Section III, respectively. Section IV contains the single seed dosimetry data of BARC OcuProsta 125I seed as well as dosimetry data of typical eye plaques loaded with BARC OcuProsta 125I seed. Quality assurance and radiation safety aspects of these eye applicators are described in Section V. A proforma of the application required to be filled in by the user institution for obtaining regulatory consent to start eye plaque therapy has also been appended to this report. (author)

  3. Ophthalmic regional blocks: management, challenges, and solutions.

    Science.gov (United States)

    Palte, Howard D

    2015-01-01

    In the past decade ophthalmic anesthesia has witnessed a major transformation. The sun has set on the landscape of ophthalmic procedures performed under general anesthesia at in-hospital settings. In its place a new dawn has ushered in the panorama of eye surgeries conducted under regional and topical anesthesia at specialty eye care centers. The impact of the burgeoning geriatric population is that an increasing number of elderly patients will present for eye surgery. In order to accommodate increased patient volumes and simultaneously satisfy administrative initiatives directed at economic frugality, administrators will seek assistance from anesthesia providers in adopting measures that enhance operating room efficiency. The performance of eye blocks in a holding suite meets many of these objectives. Unfortunately, most practicing anesthesiologists resist performing ophthalmic regional blocks because they lack formal training. In future, anesthesiologists will need to block eyes and manage common medical conditions because economic pressures will eliminate routine preoperative testing. This review addresses a variety of topical issues in ophthalmic anesthesia with special emphasis on cannula and needle-based blocks and the new-generation antithrombotic agents. In a constantly evolving arena, the sub-Tenon's block has gained popularity while the deep angulated intraconal (retrobulbar) block has been largely superseded by the shallower extraconal (peribulbar) approach. Improvements in surgical technique have also impacted anesthetic practice. For example, phacoemulsification techniques facilitate the conduct of cataract surgery under topical anesthesia, and suture-free vitrectomy ports may cause venous air embolism during air/fluid exchange. Hyaluronidase is a useful adjuvant because it promotes local anesthetic diffusion and hastens block onset time but it is allergenic. Ultrasound-guided eye blocks afford real-time visualization of needle position and local

  4. Patient education preferences in ophthalmic care

    OpenAIRE

    Rosdahl JA; Swamy L; Stinnett S; Muir KW

    2014-01-01

    Jullia A Rosdahl, Lakshmi Swamy, Sandra Stinnett, Kelly W MuirDepartment of Ophthalmology, Duke Eye Center, Duke University, Durham, NC, USABackground: The learning preferences of ophthalmology patients were examined.Methods: Results from a voluntary survey of ophthalmology patients were analyzed for education preferences and for correlation with race, age, and ophthalmic topic.Results: To learn about eye disease, patients preferred one-on-one sessions with providers as well as printed materi...

  5. Health literacy and ophthalmic patient education

    OpenAIRE

    Kelly W. Muir; Lee, Paul P.

    2010-01-01

    In 1997, Ebrahimzadeh, Davalos and Lee wrote in this journal that only 32% of the ophthalmic patient educational materials reviewed were written at or below the recommended eighth grade reading level. Since that time, the National Assessment of Adult Literacy found that more than one third of adult Americans possess only basic or below basic health literacy skills, defined as the ability to understand written information in a healthcare setting. Subsequently, investigators have shown that poo...

  6. Patent perspectives for corticosteroids based ophthalmic therapeutics.

    Science.gov (United States)

    Suresh, Preeti K; Sah, Abhishek K

    2014-01-01

    Eye inflammation, if untreated at right time poses the risk of vision loss. Several categories of drugs are available in the global market, but corticosteroids are still used for the treatment of ocular inflammation including anterior/ posterior uveitis, age related macular degeneration (AMD) and post cataract surgery inflammation. Although corticosteroids have well-documented side effects as compared to non steroidal anti-inflammatory drugs (NSAIDs), but they are still regarded as better anti-inflammatory agents for treating ocular inflammations. The prime concern with conventional formulations such as (ophthalmic solutions, suspensions, ointments) is low drug bioavailability due to precorneal barrier of the eye, tear turnover and rapid drainage of drug via nasolacrimal drainage and drug induced systemic toxicity. To overcome these limitations, various novel formulations of corticosteroids have been explored. These include nanoparticles, solid lipid nanoparticles (SLN), nanostructured lipid carriers (NLC), nanomicelles, in-situ gels, iontophoresis, liposomes, nanoemulsions, microemulsions and ocular implants for the effective ophthalmic delivery of the corticosteroids. Topical nanocarriers have also been demonstrated to be promising vectors with potential application in the ophthalmic therapeutics. This review summarizes the clinical findings and patents on various corticosteroids as ocular pharmacotherapeutics. PMID:25020063

  7. Ophthalmic regional blocks: management, challenges, and solutions

    Directory of Open Access Journals (Sweden)

    Palte HD

    2015-08-01

    Full Text Available Howard D Palte Department of Anesthesiology, Perioperative Medicine and Pain Management, Miller School of Medicine, University of Miami, Miami, FL, USA Abstract: In the past decade ophthalmic anesthesia has witnessed a major transformation. The sun has set on the landscape of ophthalmic procedures performed under general anesthesia at in-hospital settings. In its place a new dawn has ushered in the panorama of eye surgeries conducted under regional and topical anesthesia at specialty eye care centers. The impact of the burgeoning geriatric population is that an increasing number of elderly patients will present for eye surgery. In order to accommodate increased patient volumes and simultaneously satisfy administrative initiatives directed at economic frugality, administrators will seek assistance from anesthesia providers in adopting measures that enhance operating room efficiency. The performance of eye blocks in a holding suite meets many of these objectives. Unfortunately, most practicing anesthesiologists resist performing ophthalmic regional blocks because they lack formal training. In future, anesthesiologists will need to block eyes and manage common medical conditions because economic pressures will eliminate routine preoperative testing. This review addresses a variety of topical issues in ophthalmic anesthesia with special emphasis on cannula and needle-based blocks and the new-generation antithrombotic agents. In a constantly evolving arena, the sub-Tenon’s block has gained popularity while the deep angulated intraconal (retrobulbar block has been largely superseded by the shallower extraconal (peribulbar approach. Improvements in surgical technique have also impacted anesthetic practice. For example, phacoemulsification techniques facilitate the conduct of cataract surgery under topical anesthesia, and suture-free vitrectomy ports may cause venous air embolism during air/fluid exchange. Hyaluronidase is a useful adjuvant because it

  8. Magnetic alignment and patterning of cellulose fibers

    International Nuclear Information System (INIS)

    The alignment and patterning of cellulose fibers under magnetic fields are reported. Static and rotating magnetic fields were used to align cellulose fibers with sizes ranging from millimeter to nanometer sizes. Cellulose fibers of the millimeter order, which were prepared for papermaking, and much smaller fibers with micrometer to nanometer sizes prepared by the acid hydrolysis of larger ones underwent magnetic alignment. Under a rotating field, a uniaxial alignment of fibers was achieved. The alignment was successfully fixed by the photopolymerization of a UV-curable resin precursor used as matrix. A monodomain chiral nematic film was prepared from an aqueous suspension of nanofibers. Using a field modulator inserted in a homogeneous magnetic field, simultaneous alignment and patterning were achieved

  9. Magnetic alignment and patterning of cellulose fibers

    Directory of Open Access Journals (Sweden)

    Fumiko Kimura and Tsunehisa Kimura

    2008-01-01

    Full Text Available The alignment and patterning of cellulose fibers under magnetic fields are reported. Static and rotating magnetic fields were used to align cellulose fibers with sizes ranging from millimeter to nanometer sizes. Cellulose fibers of the millimeter order, which were prepared for papermaking, and much smaller fibers with micrometer to nanometer sizes prepared by the acid hydrolysis of larger ones underwent magnetic alignment. Under a rotating field, a uniaxial alignment of fibers was achieved. The alignment was successfully fixed by the photopolymerization of a UV-curable resin precursor used as matrix. A monodomain chiral nematic film was prepared from an aqueous suspension of nanofibers. Using a field modulator inserted in a homogeneous magnetic field, simultaneous alignment and patterning were achieved

  10. Magnetic alignment and patterning of cellulose fibers

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, Fumiko; Kimura, Tsunehisa [Division of Forest and Biomaterials Science, Graduate School of Agriculture, Kyoto University, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 (Japan)], E-mail: tkimura@kais.kyoto-u.ac.jp

    2008-04-01

    The alignment and patterning of cellulose fibers under magnetic fields are reported. Static and rotating magnetic fields were used to align cellulose fibers with sizes ranging from millimeter to nanometer sizes. Cellulose fibers of the millimeter order, which were prepared for papermaking, and much smaller fibers with micrometer to nanometer sizes prepared by the acid hydrolysis of larger ones underwent magnetic alignment. Under a rotating field, a uniaxial alignment of fibers was achieved. The alignment was successfully fixed by the photopolymerization of a UV-curable resin precursor used as matrix. A monodomain chiral nematic film was prepared from an aqueous suspension of nanofibers. Using a field modulator inserted in a homogeneous magnetic field, simultaneous alignment and patterning were achieved.

  11. Electrically conductive cellulose composite

    Science.gov (United States)

    Evans, Barbara R.; O'Neill, Hugh M.; Woodward, Jonathan

    2010-05-04

    An electrically conductive cellulose composite includes a cellulose matrix and an electrically conductive carbonaceous material incorporated into the cellulose matrix. The electrical conductivity of the cellulose composite is at least 10 .mu.S/cm at 25.degree. C. The composite can be made by incorporating the electrically conductive carbonaceous material into a culture medium with a cellulose-producing organism, such as Gluconoacetobacter hansenii. The composites can be used to form electrodes, such as for use in membrane electrode assemblies for fuel cells.

  12. Cellulose synthase interacting protein: A new factor in cellulose synthesis

    OpenAIRE

    Gu, Ying; Somerville, Chris

    2010-01-01

    Cellulose is the most abundant biopolymer on earth. The great abundance of cellulose places it at the forefront as a primary source of biomass for renewable biofuels. However, the knowledge of how plant cells make cellulose remains very rudimentary. Cellulose microfibrils are synthesized at the plasma membrane by hexameric protein complexes, also known as cellulose synthase complexes. The only known components of cellulose synthase complexes are cellulose synthase (CESA) proteins until the re...

  13. Development of Curcumin Based Ophthalmic Formulation

    Directory of Open Access Journals (Sweden)

    D. Anjana

    2012-01-01

    Full Text Available Problem statement: Ophthalmic drug delivery system has been a major challenge due to the distinctive and unique anatomy of the eye. The use of phytochemicals for the application in ocular disease has not been investigated much, due to poor pharmacokinetics of phytochemical and hence poor therapeutic efficacy. Approach: Curcumin is one such phytochemical known for its medicinal properties, but its usage has been limited due to its poor bioavailability. Therapeutic ocular application of curcumin for indications such as allergic conjunctivitis and use of nanotechnology based delivery system for increasing its bioavailability haven’t been explored much. Thus the objective of current study was to develop a nanoemulsification based formulation for curcumin with enhanced bioavailability and efficacy for ophthalmic therapeutic application. Different surfactants and oils were screened based on its ability to solubilize hydrophobic curcumin for developing formulation. Ultrasonication was used for dispersion of curcumin in surfactants and nanoemulsification. Charecterization of the selected formulation was done based on particle size, Transmission Electron Microscope (TEM and Scanning Electron Microscope (SEM analysis and tested for different physiochemcial properties. Results: A novel formulation was developed through nanoemulsification technology by ultrasonication using carefully selected nonionic surafactants. Acconon and Tween 80 were chosen after thorough screening studies. The ratio of curcumin: Acconon: Tween80: water (0.12:1:7:1 was found to be optimum for the formulation. Particle size analysis showed that the nano droplets are in the range of 8-22 nm. Further the TEM and SEM studies also confirmed that the nanodroplets are in spherical shape. Formulation was found to be stable as ascertained by phase separation and observational studies. Conclusion: The studies ensured the stability and formation of characteristic nanodroplets with curcumin

  14. IgG4-related ophthalmic disease

    OpenAIRE

    Mejico, Luis J.

    2014-01-01

    IgG4-related disease is a fibro-inflammatory condition with tendency to form tumors with inflammatory infiltrate with IgG4 rich plasma cells and elevation of IgG4 level in serum, which may affect virtually every organ and tissue in the organism. IgG4-related ophthalmic disease may present as dacryoadenitis, myositis, other orbital tissues, hypophysitis or pachymeningitis causing cranial neuropathies. The diagnosis of IgG4-related disease is based on a typical clinical scenario, supportive lab...

  15. Ophthalmic equipment survey 2010: preliminary results

    OpenAIRE

    Patel D; Mercer E; Mason I.

    2010-01-01

    The delivery of ophthalmic services at all levels is completely dependent on equipment: from the simple torch light to the highly sophisticated equipment used for diagnosis and treatment.In order to achieve the aims of VISON 2020: The Right to Sight and eliminate avoidable blindness by the year 2020, it is not enough to have the right equipment available at all levels of service delivery; there has to be a good maintenance and repair support service.The purpose of this equipment survey (commi...

  16. Ophthalmic equipment survey 2010: preliminary results

    Directory of Open Access Journals (Sweden)

    Patel D

    2010-09-01

    Full Text Available The delivery of ophthalmic services at all levels is completely dependent on equipment: from the simple torch light to the highly sophisticated equipment used for diagnosis and treatment.In order to achieve the aims of VISON 2020: The Right to Sight and eliminate avoidable blindness by the year 2020, it is not enough to have the right equipment available at all levels of service delivery; there has to be a good maintenance and repair support service.The purpose of this equipment survey (commissioned by this journal was to obtain an overview of the key issues and challenges faced by eye health providers with regard to their equipment.

  17. Radiation sterilization of pharmaceutical-ophthalmic ointments

    International Nuclear Information System (INIS)

    The ophthalmic suspension whose active compounds are antibiotic and corticosteroids, was submitted, in the final package, to radiation in a Cobalt-60 source and their stability to gamma radiation has been investigated. This procedure aims to substitute the conventional aseptic method of manufacturing and packaging for radiation sterilization. Microbiological studies have been carried out to determine the minimum absorbed dose achieving the required Sterility Assurance Level (SAL) of 10-6. The microbiological and product stability data obtained till the present time, support the use of radiation sterilization. (author)

  18. 21 CFR 524.960 - Flumethasone, neomycin sulfate, and polymyxin B sulfate ophthalmic solutions.

    Science.gov (United States)

    2010-04-01

    ... sulfate ophthalmic solutions. 524.960 Section 524.960 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS OPHTHALMIC AND... ophthalmic solutions. (a) Specifications. Each milliliter of ophthalmic preparation contains 0.10...

  19. 21 CFR 886.1430 - Ophthalmic contact lens radius measuring device.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic contact lens radius measuring device... SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1430 Ophthalmic contact lens radius measuring device. (a) Identification. An ophthalmic contact lens radius measuring device...

  20. CELLULOSIC NANOCOMPOSITES: A REVIEW

    Directory of Open Access Journals (Sweden)

    Martin A. Hubbe

    2008-08-01

    Full Text Available Because of their wide abundance, their renewable and environmentally benign nature, and their outstanding mechanical properties, a great deal of attention has been paid recently to cellulosic nanofibrillar structures as components in nanocomposites. A first major challenge has been to find efficient ways to liberate cellulosic fibrils from different source materials, including wood, agricultural residues, or bacterial cellulose. A second major challenge has involved the lack of compatibility of cellulosic surfaces with a variety of plastic materials. The water-swellable nature of cellulose, especially in its non-crystalline regions, also can be a concern in various composite materials. This review of recent work shows that considerable progress has been achieved in addressing these issues and that there is potential to use cellulosic nano-components in a wide range of high-tech applications.

  1. Cellulose-silica aerogels.

    Science.gov (United States)

    Demilecamps, Arnaud; Beauger, Christian; Hildenbrand, Claudia; Rigacci, Arnaud; Budtova, Tatiana

    2015-05-20

    Aerogels based on interpenetrated cellulose-silica networks were prepared and characterised. Wet coagulated cellulose was impregnated with silica phase, polyethoxydisiloxane, using two methods: (i) molecular diffusion and (ii) forced flow induced by pressure difference. The latter allowed an enormous decrease in the impregnation times, by almost three orders of magnitude, for a sample with the same geometry. In both cases, nanostructured silica gel was in situ formed inside cellulose matrix. Nitrogen adsorption analysis revealed an almost threefold increase in pores specific surface area, from cellulose aerogel alone to organic-inorganic composite. Morphology, thermal conductivity and mechanical properties under uniaxial compression were investigated. Thermal conductivity of composite aerogels was lower than that of cellulose aerogel due to the formation of superinsulating mesoporous silica inside cellulose pores. Furthermore, composite aerogels were stiffer than each of reference aerogels. PMID:25817671

  2. Radioactivity measurements for some ophthalmic glasses

    International Nuclear Information System (INIS)

    The main aim of the present work is to implant the latest ICRP/IAEA recommendations related to exemption and clearness to the Ophthalmic Glass. As consumer product, glass lenses may contain trace quantities of uranium, thorium and potassium. Glass lenses under investigation were monitored for the detection of gamma rays and beta particles using radiation measuring devices. Using high purity germanium detector radioactivity concentration was estimated in Bq/kg. Activity concentration of 226 Ra, Th-232 and K-40 were determined using the energy gamma lines of 2l4Pb (352 keV), 212Pb (238 keV) and 1460 keV gamma line for 40K respectively .Experimental results showed that radioactivity concentration for radium -226 varies from 0.19 to 4.98 Bq/kg of radium-226, from to 0.18 to 2.83 Bq/kg for thorium -232 and from 0.8 to 1.13 Bq/kg for potassium. Implementing new ICRP recommendation of exemption and clearness indicated that several Ophthalmic Glass should not be in use

  3. National Strategies of Ophthalmic Education in Iran

    Directory of Open Access Journals (Sweden)

    B Einollahi

    2012-01-01

    Full Text Available Background: Academic medicine is in a state of dramatic transformation. For this reason strategic thinking is the most essential part of educational planning. The main purpose of the present study was developing the strategic educational planning of Ophthalmology in Iran from 2007 to 2010Methods: A qualitative investigation using focus group discussion has been implemented successfully for developing educational planning. Six to twelve representatives of key stakeholders in the ophthalmic education of Iran participated to this study.Results: Strengths, weaknesses, opportunities and threats of ophthalmology education in Iran were analyzed. Strategic goals in education, research, and health service providing domains were being developed. Educational goals were defined as training of human resources in accordance with the community needs at the level of general practitioner, specialist, and fellowships in ophthalmology. Research goals of the program were defined as scientific inter-departmental and international communications, in order to promote the level of education, research, and treatment in the country. Also, in the field of health services according to the community needs, providing services by the means of advanced and cost effective methods were defined as strategic objectives.Conclusion: Based on this strategic plan in the last three years ophthalmic education in Iran shall be many changes in educational, research and health care provision for social accountability.

  4. Programmable diffractive lens for ophthalmic application

    Science.gov (United States)

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

    2014-06-01

    Pixelated liquid crystal displays have been widely used as spatial light modulators to implement programmable diffractive optical elements, particularly diffractive lenses. Many different applications of such components have been developed in information optics and optical processors that take advantage of their properties of great flexibility, easy and fast refreshment, and multiplexing capability in comparison with equivalent conventional refractive lenses. We explore the application of programmable diffractive lenses displayed on the pixelated screen of a liquid crystal on silicon spatial light modulator to ophthalmic optics. In particular, we consider the use of programmable diffractive lenses for the visual compensation of refractive errors (myopia, hypermetropia, astigmatism) and presbyopia. The principles of compensation are described and sketched using geometrical optics and paraxial ray tracing. For the proof of concept, a series of experiments with artificial eye in optical bench are conducted. We analyze the compensation precision in terms of optical power and compare the results with those obtained by means of conventional ophthalmic lenses. Practical considerations oriented to feasible applications are provided.

  5. [Suprapubic catheter insertion].

    Science.gov (United States)

    Neumann, Eva; Schwentner, Christian

    2016-01-01

    The suprapubic catheter enables a percutaneous drainage of urine. The insertion is made superior of the pubic bone through the abdominal wall into the bladder. It allows a permanent drainage of urine bypassing the urethra. The insertion of a suprapubic catheter requires knowledge and expertise. This paper summarizes the basic background and allows to follow the practical application step by step. PMID:26800072

  6. Tie rod insertion test

    CERN Multimedia

    B. LEVESY

    2002-01-01

    The superconducting coil is inserted in the outer vaccum tank and supported by a set of tie rods. These tie rods are made of titanium alloy. This test reproduce the final insertion of the tie rods inside the outer vacuum tank.

  7. Computation of Dioptric and Magnification Matrices in Ophthalmic Lenses

    Science.gov (United States)

    Barbero, S.

    2014-06-01

    The diopter power and magnification matrices characterize the first-order properties of ophthalmic lenses for different gaze directions. Therefore an efficient method to compute them is highly valuable in ophthalmic lens design and optical performance simulations. I present a novel method to numerically compute these matrices in ophthalmic lenses comprising any set of arbitrary surfaces. The method is based on computing one base ray, along the gaze direction, and two rays close to it. These two rays are obtained varying a small parameter that indicates their separation from the base ray. The method was validated comparing the results with a single refractive surface where exact solutions are directly obtained.

  8. Ocular and systemic adverse effects of ophthalmic and non ophthalmic medications.

    Science.gov (United States)

    Izazola-Conde, C; Zamora-de la Cruz, D; Tenorio-Guajardo, G

    2011-01-01

    Information related to adverse drug effects caused by ocular medications and ocular adverse effects of systemically administered drugs has increased over the last several decades. Here we review the medical literature over the last four decades to both quantitatively and qualitatively determine the adverse effects of ocular drugs and ocular toxicity of non-ocular drugs. A systematic bibliographic review of the literature was performed with the following terms: "drug treatment", "drug therapy", "ocular adverse effects", "ocular side effects", "ocular toxicity", "systemic side effects", "systemic adverse effects", "systemic toxicity", "ocular drug" and "ophthalmic drug" using the Boolean operators or, and, not. Searches focused on: (1) Ocular side/adverse effects of ophthalmic drugs; (2) Ocular side/adverse effects of systemic drugs; (3) Systemic side/adverse effects of ophthalmic drugs. PubMed was used to perform searches. Limits included: species, human and field tag, abstract/title, dates from 01/01/1971 to 31/12/2010. A sub-selection of references was made by discarding articles that were irrelevant for the topics listed above. Adverse effects of alpha2-adrenergic agonists, beta-adrenergic antagonists, quinine derivatives and antituberculosis agents appear in the literature throughout the period of the review. Adverse effects of newer drugs such as amiodarone, phosphodiesterase 5 inhibitors, antiepileptics, tamoxifen, and its interactions have been published principally in the last two decades. It is imperative for patient safety that knowledge of the adverse effects of drugs on the eye whether topically or systemically administered, and the possible systemic effects of drugs given as ophthalmic medications be emphasized to clinicians. PMID:22423585

  9. Ophthalmic parameters in adult Shih Tzu dogs

    Directory of Open Access Journals (Sweden)

    Karina Kamachi Kobashigawa

    2015-07-01

    Full Text Available Ocular surface diseases are often diagnosed in brachycephalic dogs. The ophthalmic parameters of the Shih Tzu dogs are evaluated in this study since this breed is among the most commonly affected by these diseases. In this study, ophthalmic parameters of this breed were partly studied under physical restraint. Schirmer tear test, breakup time test, aesthesiometry, biomicroscopy, non-contact specular microscopy, laser flaremetry, applanation tonometry, ultrasonography and ophthalmoscopy were carried in 48 eyes of 24 male and female dogs, aged from two to four years, weighing between 5 and 10kg. All dogs were from a breeding kennel. Descriptive statistics were applied to the data. Mean and standard error for Schirmer tear test was 26.145±0.803mm min-1; breakup time test, 13.668±0.538s; and aesthesiometry, 2.395±0.071cm. The biomicroscopy evaluation showed that 70.83% of the eyes had medial entropion; 42% caruncular trichiasis; 33% distichiasis, 27% mild paracentral corneal opacity; and 13% corneal melanosis. Mean and standard error for endothelial cell density was 2221.591±20.161cells mm-2; endothelial cell hexagonality, 63.770±1.805%; endothelial cell area, 451.895±4.179mm2; central corneal thickness, 0.490±0.007 mm; laser flaremetry, 1.720±0.216PC ms-1; applanation tonometry, 16.118±0.460mmHg; axial length, 20.255±0.134mm; lens thickness, 6.624±0.031mm; anterior chamber, 4.064±0.109mm; and vitreous chamber, 9.565±0.054mm. Ophthalmoscopy findings were not different from previous reports for other breeds. The results showed that the ophthalmic Shih Tzu parameters did not differ from other breeds according to data in the literature, except for the breakup time and Cochet-Bonnet aesthesiometry.

  10. Flow analysis of the ophthalmic artery

    Energy Technology Data Exchange (ETDEWEB)

    Harada, Kuniaki; Hashimoto, Masato; Bandoh, Michio; Odawara, Yoshihiro; Kamagata, Masaki; Shirase, Ryuji [Sapporo Medical Univ. (Japan). Hospital

    2003-02-01

    The purpose of this study was to analyze the hemodynamics of ophthalmic artery flow using phase contrast MR angiography (PC-MRA). A total of 14 eyes from 10 normal volunteers and a patient with normal tension glaucoma (NTG) were analyzed. The optimal conditions were time repetition (TR)/echo time (TE)/flip angle (FA)/nex=40 ms/minimum/90 deg/2, field of view (FOV)=6 cm, matrix size=256 x 256. The resistive index (RI) and pulsatillity index (PI) values were significantly raised in the patient with NTG when compared to the control group. We therefore believe that PC-MRA may be a useful clinical tool for the assessment of the mechanism of NTG. (author)

  11. Dosimetry of Sr-90 ophthalmic applicators

    International Nuclear Information System (INIS)

    Sr-90 ophthalmic applicators are commonly used for the treatment of superficial eye disorders. Although a variety of dosimetric devices such as film, thermoluminescent dosimeters (TLD's), ion chambers, and radiochromic foils have been used to measure the peak dose at the applicator surface, there is no internationally agreed upon calibration procedure. Recently, large discrepancies among calibrations of the same applicator at three institutions have been reported. Here we describe a technique to obtain the peak dose rate at the applicator surface using LiF TLD's. The technique can be used for the calibration of flat as well as curved surface applicators. Results for two flat and three concave applicators are presented. Our measurement of the surface dose rate for one of the flat applicators is compared with those obtained by four other institutions, each using different dosimetric devices

  12. A survey of optometrists' ophthalmic medication prescribing

    Directory of Open Access Journals (Sweden)

    Gonzalez AL

    2014-03-01

    Full Text Available Agustin L Gonzalez, Nikki Bennett, Rakesh Lakhani Inter American University, School of Optometry, Bayamón, Puerto Rico Abstract: Optometry is recognized as a primary care profession within the health care system. For years, much emphasis has been placed on the core function of optometrists as prescribers for refractive correction, yet little is known about their medication prescribing habits. Optometrists have had the ability to prescribe medications for the last 30 years, and still little information is available about optometric pharmaceutical trends. This study consists of a survey aimed at obtaining self-reported data to depict optometrists' likelihood of prescribing ophthalmic medications during a regular clinic day. We conclude that optometrists are indeed using medications in their clinics, and the trends are very similar to the epidemiological distribution of eye disorders in the general population. Keywords: optometry, prescription drug audit, pharmacoepidemiology

  13. M-sequences in ophthalmic electrophysiology.

    Science.gov (United States)

    Müller, Philipp L; Meigen, Thomas

    2016-01-01

    The aim of this review is to use the multimedia aspects of a purely digital online publication to explain and illustrate the highly capable technique of m-sequences in multifocal ophthalmic electrophysiology. M-sequences have been successfully applied in clinical routines during the past 20 years. However, the underlying mathematical rationale is often daunting. These mathematical properties of m-sequences allow one not only to separate the responses from different fields but also to analyze adaptational effects and impacts of former events. By explaining the history, the formation, and the different aspects of application, a better comprehension of the technique is intended. With this review we aim to clarify the opportunities of m-sequences in order to motivate scientists to use m-sequences in their future research. PMID:26818968

  14. An historical ophthalmic study of Jane Austen.

    Science.gov (United States)

    Wilson, Graham A

    2012-11-01

    Today, no other classic novelist has the popularity or power of Jane Austen, and in 2013 the world will celebrate 200 years of her comic masterpiece Pride and Prejudice. Her millions of fans have an abiding fascination with all aspects of her life, including her health and the cause of her death. This historical ophthalmic study of Jane Austen, based on very incomplete medical bibliographic data, finds that she had a mild ocular surface disorder from age 23. This disorder did not significantly impact on her visual performance for writing. There are many references to eyes in her novels, but Jane's eyes and those of her characters cannot contribute further to the debate around the cause of her death at age 41. PMID:22923461

  15. Flow analysis of the ophthalmic artery

    International Nuclear Information System (INIS)

    The purpose of this study was to analyze the hemodynamics of ophthalmic artery flow using phase contrast MR angiography (PC-MRA). A total of 14 eyes from 10 normal volunteers and a patient with normal tension glaucoma (NTG) were analyzed. The optimal conditions were time repetition (TR)/echo time (TE)/flip angle (FA)/nex=40 ms/minimum/90 deg/2, field of view (FOV)=6 cm, matrix size=256 x 256. The resistive index (RI) and pulsatillity index (PI) values were significantly raised in the patient with NTG when compared to the control group. We therefore believe that PC-MRA may be a useful clinical tool for the assessment of the mechanism of NTG. (author)

  16. Verification of ophthalmic brachytherapy treatment planning

    International Nuclear Information System (INIS)

    Ophthalmic brachytherapy dose calculations were performed as an independent verification of commercial dosimetry software (BEBIG Plaque Simulator). Excel spreadsheets were constructed to follow the formalism of the AAPM Task Group No. 43. As a software commissioning tool, TG43 seed-based coordinates were reformatted to be compatible with plaque-based BEBIG dose tables for centrally positioned seeds. Plaque central axis doses were also calculated for rings of seeds. Close agreement with BEBIG doses was obtained in both cases. Tailored spreadsheet versions were subsequently created to verify patient treatment plans. Treatment time and dose to a specified central-axis point are calculated for ROPES plaques fully loaded with I-125 model 6702 seeds. Copyright (2001) Australasian College of Physical Scientists and Engineers in Medicine

  17. A Multi-Electrode Electric Field Based Sensing System For Ophthalmic Anesthesia Training.

    Science.gov (United States)

    Mukherjee, Biswarup; George, Boby; Sivaprakasam, Mohanasankar

    2015-06-01

    Local anesthesia administration prior to ophthalmic surgery involves inserting a syringe needle into a confined intraorbital space at the proper position, angle and depth. During this procedure ocular structures must remain unhurt and systemic complications must be avoided while achieving quick akinesia and analgesia. Animal cadavers do not emulate human anatomy accurately and human subject based training entails risk to the patient. Therefore, a training system that closely replicates the human ocular and orbital anatomy and provides the trainee with real-time feedback on the safety and effectiveness of the block administered would help reduce risks involved with real life procedures. This paper presents an anatomically accurate, rapid-prototyped manikin based training system for ophthalmic anesthetic blocks. The depth of penetration of the needle, the proximity of the needle to extraocular muscles and the touch of the needle to the muscles or optic nerve is detected by a multi-electrode electric field/capacitive sensing system. The eye structure of the manikin does not have any electrical connections to it, rendering it replaceable, thus, enabling the emulation of anatomical variations due to pathologies of the eye. A virtual instrument measures and computes the position of the needle and displays it to the trainee through an intuitive GUI with a 3D display of the orbital anatomy. The proposed capacitive sensing scheme has been validated by tests performed on a prototype system, thus demonstrating its usefulness for practical training purposes. PMID:25361511

  18. Ophthalmic Injuries in Orbito-Zygomatic Fractures

    International Nuclear Information System (INIS)

    Objective: To assess the frequency and severity of ophthalmic injuries in patients with orbito-zygomatic fractures. Study Design: A case series. Place and Duration of Study: Oral and Maxillofacial Department, KEMU/Mayo Hospital Lahore, from January 2009 to December 2011. Methodology: Patients with orbito-zygomatic fractures were divided into three groups. Group-1 patients had fracture of floor/medial wall of the orbit (orbital-blow out fracture). Group-2 had comminuted orbito-zygomatic fractures. Group-3 had simple zygomatic bone fractures. Frequency and types of ocular injuries were determined on each group. Results: There were 296 (260 male, 36 female) patients with mean age of 31.7 years. Group-1 (n = 20) had 28 ocular findings in 12 (60%) patients including diplopia (n = 10, 36%), enophthalmos (n = 6, 14%), and hyphema, vitreous hemorrhage, retinal hemorrhage, choroidal rupture, traumatic mydriasis, and commotio retinae in 2 cases, 7% each. In Group-2 (n = 106), 44 ocular findings were identified in 30 (28%) patients including diplopia (n = 10, 23%), enophthalmos (n = 4, 9%), commotio retinae (n = 10, 23%), reduced visual acuity (n = 6, 14%), retinal hemorrhage (n = 4, 9%) and corneal laceration, corneal abrasion, retinal detachment, traumatic mydriasis, and canthal laceration in 2 cases, 4.5%. In Group-3 (n = 170), 22 ocular findings were seen in 16 (9%) patients included diplopia (n = 10, 45%), enophthalmos (n = 4, 18%), and retinal tear, hyphema, angle recession, and traumatic mydriasis in 2 cases, (9%) each. Conclusion: Ophthalmic injuries are a common complication of orbitozygomatic fractures occurring in about 20% of patients in this study, most frequent in the orbital blow fractures subgroup. Ophthalmology consultation is recommended for patients presenting with midface fractures. (author)

  19. Latest technological developments in ophthalmic OCT

    International Nuclear Information System (INIS)

    Recent developments of ultrabroad bandwidth light sources and detection technology have enabled significant improvement of ophthalmic axial OCT imaging resolution, demonstrating the potential of ultrahigh resolution OCT (UHR OCT) to perform three-dimensional non-invasive optical biopsy, i. e. the in vivo visualization of microstructural morphology in situ, which had previously only been possible with histopathology. Therefore UHR OCT allows detection of intraretinal changes that can be used for diagnosis of retinal disease in its early stages, when treatment is most effective and irreversible damage can be prevented or delayed. Furthermore it may provide a better understanding of the pathogenesis of several macular pathologies as well as the development of new therapy approaches. Other recent developments of ophthalmic OCT include nearly cellular level resolution, depth resolved functional imaging of the living human retina as well as OCT imaging with enhanced penetration into the choroid by employing novel wavelength regions. Using adaptive optics to correct higher order aberrations of the human eye in combination with high speed, three-dimensional UHR OCT enables unprecedented in vivo volumetric visualization of intraretinal morphology. Preliminary results demonstrate visualization of retinal features that might correspond to the terminal bars of photoreceptors at the external limiting membrane. In addition, extensions of UHR OCT are developed that should provide non-invasive depth resolved functional imaging of the retina, including spectroscopic, blood flow or physiologic tissue information. These extensions of OCT should not only improve image contrast, but should also enable the differentiation of retinal pathologies via localized spectroscopic properties or functional state. (author)

  20. Ophthalmic Diseases in Patients With Obstructive Sleep Apnea.

    Science.gov (United States)

    Skorin, Leonid; Knutson, Rachel

    2016-08-01

    Symptomatic obstructive sleep apnea (OSA) affects 2% of women and 4% of men, but the prevalence of asymptomatic OSA is significantly higher. Several ophthalmic conditions are associated with OSA, including floppy eyelid syndrome, glaucoma, nonarteritic anterior ischemic optic neuropathy, papilledema, keratoconus, and central serous chorioretinopathy. The purpose of this review is to provide primary care physicians with a general knowledge of the signs, symptoms, and management of the ophthalmic diseases associated with OSA. PMID:27455101

  1. Sildenafil dilates ophthalmic artery in type 2 diabetic patients

    OpenAIRE

    Zwain, Akeel AMH; Hadi, Najah R.; Al-Mudhaffer, Ahmed M

    2013-01-01

    Background: Conflicting reports exist on the effect of sildenafil on ophthalmic artery blood flow; many visual disturbances due to vascular insult were reported with the use of sildenafil in diabetic patients like nonarteritic ischemic optic neuropathy. Objectives: The present work aimed to investigate whether sildenafil modulates ophthalmic artery vasoreactivity in patients with type 2 diabetes mellitus. Literature reports on this aspect are lacking. Methods: A total of 35 male subjects were...

  2. Risk factors of ophthalmic disorders in children with developmental delay

    DEFF Research Database (Denmark)

    Sandfeld, L.N.; Jensen, H.; Skov, L.

    2008-01-01

    PURPOSE: To identify diagnoses that increase the risk of ophthalmic disorders in developmentally delayed children. METHODS: A cross-sectional study of 1126 Danish children with developmental delay (IQ Udgivelsesdato: 2008/12......PURPOSE: To identify diagnoses that increase the risk of ophthalmic disorders in developmentally delayed children. METHODS: A cross-sectional study of 1126 Danish children with developmental delay (IQ Udgivelsesdato: 2008/12...

  3. Metabolic Acidosis with Ophthalmic Dorzolamide in a Neonate.

    Science.gov (United States)

    Capino, Amanda C; Dannaway, Douglas C; Miller, Jamie L

    2016-01-01

    Carbonic anhydrase inhibitors are a common cause of normal anion gap metabolic acidosis; however, development is less commonly associated with ophthalmic administration of these agents. We report a case of a premature neonate who was being treated at our institution with betaxolol, dorzolamide, and latanoprost ophthalmic products for suspected bilateral congenital glaucoma. In addition, the patient was also receiving caffeine, ursodiol, and acidified liquid human milk fortifier. The patient developed a normal anion gap metabolic acidosis, and both dorzolamide ophthalmic solution and the acidified human milk fortifier were considered potential causes. Upon discontinuation of the dorzolamide ophthalmic solution and the switching of liquid human milk fortifiers, the normal anion gap metabolic acidosis gradually resolved. As a result of the pH and acidity, the acidified liquid human milk fortifier is thought to be associated with an anion gap acidosis; therefore, dorzolamide is suspected to be the primary cause of a normal gap acidosis. This case demonstrates that systemic effects can occur with ophthalmic administration of dorzolamide in a premature neonate. Ophthalmic agents should not be overlooked as a potential cause of systemic toxicity. PMID:27453705

  4. Palladium-103 versus iodine-125 for ophthalmic plaque radiotherapy

    International Nuclear Information System (INIS)

    A dosimetry study compared the use of I-125 vs. Pd-103 radioactive seeds for ophthalmic plaque brachytherapy. Pd-103 seeds in ophthalmic plaques were used to treat 15 patients with intraocular malignant melanoma. Computer-aided simulations were performed to evaluate the intraocular dose distribution of I-125 versus Pd-103 ophthalmic plaques (delivering equivalent apex doses). Seven target points were selected. Starting at the outer scleral surface, four were located along the central axis of the plaque: the 1 mm point (the inner sclera), the 6 mm point, the tumors apex, and the opposite eye wall. They also evaluated the fovea, optic nerve, and the lens because they were considered to be critical structures. These studies demonstrated that the lower energy photons generated by Pd-103 seeds (average 21 KeV) in ophthalmic plaques were more rapidly absorbed in tissue than photons generated by I-125 (average 28 KeV). Therefore, during ophthalmic plaque radiotherapy, Pd-103 photons were found to be more rapidly absorbed within the tumor and less likely to reach most normal ocular structures. On average, the use of Pd-103 decreased the dose to the fovea by 5.7%, to the optic nerve by 8.4%, to the lens by 26%, and to the opposite eye wall by 38.4%. Pd-103 ophthalmic plaque brachytherapy resulted in slightly more irradiation of the tumor and less radiation to most normal ocular structures. 36 refs., 1 fig., 3 tabs

  5. Dose uniformity of loteprednol etabonate ophthalmic gel (0.5%) compared with branded and generic prednisolone acetate ophthalmic suspension (1%)

    OpenAIRE

    Marlowe ZT; Davio SR

    2013-01-01

    Zora T Marlowe, Stephen R DavioPharmaceutical Product Development, Global Pharmaceutical Research and Development, Bausch and Lomb, Inc, Rochester, NY, USAIntroduction: Loteprednol etabonate (LE) ophthalmic gel 0.5% (Lotemax®) is a new polycarbophil-based, nonsettling topical ophthalmic formulation. The formulation is a semisolid gel at rest and a shear thinning fluid when expressed through a dropper tip. The present study was undertaken to determine how the nonsettling character of L...

  6. AmrZ regulates cellulose production in Pseudomonas syringae pv. tomato DC3000.

    Science.gov (United States)

    Prada-Ramírez, Harold A; Pérez-Mendoza, Daniel; Felipe, Antonia; Martínez-Granero, Francisco; Rivilla, Rafael; Sanjuán, Juan; Gallegos, María-Trinidad

    2016-03-01

    In Pseudomonas syringae pv. tomato DC3000, the second messenger c-di-GMP has been previously shown to stimulate pellicle formation and cellulose biosynthesis. A screen for genes involved in cellulose production under high c-di-GMP intracellular levels led to the identification of insertions in two genes, wssB and wssE, belonging to the Pto DC3000 cellulose biosynthesis operon wssABCDEFGHI. Interestingly, beside cellulose-deficient mutants, colonies with a rougher appearance than the wild type also arouse among the transposants. Those mutants carry insertions in amrZ, a gene encoding a transcriptional regulator in different Pseudomonas. Here, we provide evidence that AmrZ is involved in the regulation of bacterial cellulose production at transcriptional level by binding to the promoter region of the wssABCDEFGHI operon and repressing cellulose biosynthesis genes. Mutation of amrZ promotes wrinkly colony morphology, increased cellulose production and loss of motility in Pto DC3000. AmrZ regulon includes putative c-di-GMP metabolising proteins, like AdcA and MorA, which may also impact those phenotypes. Furthermore, an amrZ but not a cellulose-deficient mutant turned out to be impaired in pathogenesis, indicating that AmrZ is a key regulator of Pto DC3000 virulence probably by controlling bacterial processes other than cellulose production. PMID:26564578

  7. Cellulose Synthesis and Its Regulation

    OpenAIRE

    Li, Shundai; Bashline, Logan; Lei, Lei; Gu, Ying

    2014-01-01

    Cellulose, the most abundant biopolymer synthesized on land, is made of linear chains of ß (1–4) linked D-glucose. As a major structural component of the cell wall, cellulose is important not only for industrial use but also for plant growth and development. Cellulose microfibrils are tethered by other cell wall polysaccharides such as hemicellulose, pectin, and lignin. In higher plants, cellulose is synthesized by plasma membrane-localized rosette cellulose synthase complexes. Despite the re...

  8. Fulton Cellulosic Ethanol Biorefinery

    Energy Technology Data Exchange (ETDEWEB)

    Sumait, Necy [BlueFire Ethanol, Irvine, CA (United States); Cuzens, John [BlueFire Ethanol, Irvine, CA (United States); Klann, Richard [BlueFire Ethanol, Irvine, CA (United States)

    2015-07-24

    Final report on work performed by BlueFire on the deployment of acid hydrolysis technology to convert cellulosic waste materials into renewable fuels, power and chemicals in a production facility to be located in Fulton, Mississippi.

  9. ALS insertion devices

    International Nuclear Information System (INIS)

    The Advanced Light Source (ALS), the first US third generation synchrotron radiation source, is currently under construction at the Lawrence Berkeley Laboratory. The low-emittance, 1.5 GeV electron storage ring and the insertion devices are specifically designed to produce high brightness beams in the UV to soft X-Ray range. The planned initial complement of insertion devices includes four 4.6 m long undulators, with period lengths of 3.9 cm, 5.0 cm (2) and 8.0 cm, and a 2.9 m long wiggler of 16 cm period length. Undulator design is well advanced and fabrication has begun on the 5.0 cm and 8.0 cm period length undulators. This paper discusses ALS insertion device requirements; general design philosophy; and design of the magnetic structure, support structure/drive systems, control system and vacuum system. 18 refs., 9 figs., 5 tabs

  10. Dose uniformity of loteprednol etabonate ophthalmic gel (0.5% compared with branded and generic prednisolone acetate ophthalmic suspension (1%

    Directory of Open Access Journals (Sweden)

    Marlowe ZT

    2013-12-01

    Full Text Available Zora T Marlowe, Stephen R DavioPharmaceutical Product Development, Global Pharmaceutical Research and Development, Bausch and Lomb, Inc, Rochester, NY, USAIntroduction: Loteprednol etabonate (LE ophthalmic gel 0.5% (Lotemax® is a new polycarbophil-based, nonsettling topical ophthalmic formulation. The formulation is a semisolid gel at rest and a shear thinning fluid when expressed through a dropper tip. The present study was undertaken to determine how the nonsettling character of LE ophthalmic gel affects dose uniformity. Prednisolone acetate ophthalmic suspension 1% (Pred Forte® and a generic prednisolone acetate suspension 1% were used as comparators.Methods: Drug concentrations of LE ophthalmic gel, Pred Forte, and a generic prednisolone acetate suspension were determined following simulated dosing – consisting of 2 drops, expressed four times daily for 2 weeks, with bottles that were shaken or not shaken immediately prior to expressing the drops. Drug concentrations were determined using a reverse-phase high-performance liquid chromatography (HPLC method and reported as a percentage of the declared (labeled concentration. Comparative kinetics of drug particle sedimentation were also determined for each formulation, using dispersion analysis under gravity.Results: Mean drug concentrations in drops of all three formulations were within a few percentage points of the declared concentration when the bottles were shaken for 5 seconds prior to dispensing. Only LE ophthalmic gel showed consistent and on-target concentrations when the bottles were unshaken prior to dispensing, with a mean (standard deviation [SD] percent declared concentration of 102% (1.92% over the 2-week dosing regimen. Drug concentrations for the branded and generic prednisolone acetate suspensions following expression from unshaken bottles were highly variable (overall relative SDs of 16.8% and 20.3%, respectively, with mean concentrations for both falling significantly

  11. Stability study of azithromycin in ophthalmic preparations

    Directory of Open Access Journals (Sweden)

    Andréia de Haro Moreno

    2009-06-01

    Full Text Available A stability study of azithromycin in ophthalmic preparations was developed by submission to different types of light, temperature and pH, using the biodiffusion assay (cylinder 3 x 3 for the quantifications. Bacillus subtilis, ATCC 9372, was used as test organism. The used concentration range was of 50 to 200 µg/mL. The study demonstrated that the drug suffered degradation when submitted to the ultraviolet light, germicide light, solar luminosity, acid solution, basic solution and hydrogen peroxide solution. The results were analyzed by the analysis of variance (ANOVA.O estudo de estabilidade de azitromicina em preparações oftálmicas foi realizado após exposição a diferentes tipos de luz, temperatura e pH, utilizando o método de difusão em ágar (cilindros 3 x 3 para as quantificações. A faixa de concentração foi de 50 a 200 µg/mL. O estudo demonstrou que o fármaco sofreu degradação quando submetido às luzes ultravioleta, germicida e solar, e a soluções ácida, alcalina e de peróxido de hidrogênio. Os resultados foram analisados através da análise da variância (ANOVA.

  12. New eye phantom for ophthalmic surgery

    Science.gov (United States)

    Fogli, Gessica; Orsi, Gianni; De Maria, Carmelo; Montemurro, Francesca; Palla, Michele; Rizzo, Stanislao; Vozzi, Giovanni

    2014-06-01

    In this work, we designed and realized a new phantom able to mimic the principal mechanical, rheological, and physical cues of the human eye and that can be used as a common benchmark to validate new surgical procedures, innovative vitrectomes, and as a training system for surgeons. This phantom, in particular its synthetic humor vitreous, had the aim of reproducing diffusion properties of the natural eye and can be used as a system to evaluate the pharmacokinetics of drugs and optimization of their dose, limiting animal experiments. The eye phantom was built layer-by-layer starting from the sclera up to the retina, using low cost and easy to process polymers. The validation of the phantom was carried out by mechanical characterization of each layer, by diffusion test with commercial drugs into a purposely developed apparatus, and finally by a team of ophthalmic surgeons. Experiments demonstrated that polycaprolactone, polydimethylsiloxane, and gelatin, properly prepared, are the best materials to mimic the mechanical properties of sclera, choroid, and retina, respectively. A polyvinyl alcohol-gelatin polymeric system is the best for mimicking the viscosity of the human humor vitreous, even if the bevacizumab half-life is lower than in the human eye.

  13. Patient education preferences in ophthalmic care

    Directory of Open Access Journals (Sweden)

    Rosdahl JA

    2014-04-01

    Full Text Available Jullia A Rosdahl, Lakshmi Swamy, Sandra Stinnett, Kelly W MuirDepartment of Ophthalmology, Duke Eye Center, Duke University, Durham, NC, USABackground: The learning preferences of ophthalmology patients were examined.Methods: Results from a voluntary survey of ophthalmology patients were analyzed for education preferences and for correlation with race, age, and ophthalmic topic.Results: To learn about eye disease, patients preferred one-on-one sessions with providers as well as printed materials and websites recommended by providers. Patients currently learning from the provider were older (average age 59 years, and patients learning from the Internet (average age 49 years and family and friends (average age 51 years were younger. Patients interested in cataracts, glaucoma, macular degeneration, and dry eye were older; patients interested in double vision and glasses were younger. There were racial differences regarding topic preferences, with Black patients most interested in glaucoma (46%, diabetic retinopathy (31%, and cataracts (28% and White patients most interested in cataracts (22%, glaucoma (22%, and macular degeneration (19%.Conclusion: Most ophthalmology patients preferred personalized education: one-on-one with their provider or a health educator and materials (printed and electronic recommended by their provider. Age-related topics were more popular with older patients, and diseases with racial risk factors were more popular with high risk racial groups.Keywords: patient education, eye disease, cataracts, macular degeneration, glaucoma, diabetic retinopathy

  14. Patient education preferences in ophthalmic care

    Science.gov (United States)

    Rosdahl, Jullia A; Swamy, Lakshmi; Stinnett, Sandra; Muir, Kelly W

    2014-01-01

    Background The learning preferences of ophthalmology patients were examined. Methods Results from a voluntary survey of ophthalmology patients were analyzed for education preferences and for correlation with race, age, and ophthalmic topic. Results To learn about eye disease, patients preferred one-on-one sessions with providers as well as printed materials and websites recommended by providers. Patients currently learning from the provider were older (average age 59 years), and patients learning from the Internet (average age 49 years) and family and friends (average age 51 years) were younger. Patients interested in cataracts, glaucoma, macular degeneration, and dry eye were older; patients interested in double vision and glasses were younger. There were racial differences regarding topic preferences, with Black patients most interested in glaucoma (46%), diabetic retinopathy (31%), and cataracts (28%) and White patients most interested in cataracts (22%), glaucoma (22%), and macular degeneration (19%). Conclusion Most ophthalmology patients preferred personalized education: one-on-one with their provider or a health educator and materials (printed and electronic) recommended by their provider. Age-related topics were more popular with older patients, and diseases with racial risk factors were more popular with high risk racial groups. PMID:24812493

  15. Optimization of 125I ophthalmic plaque brachytherapy

    International Nuclear Information System (INIS)

    Episcleral plaques containing 125I sources are often used in the treatment of ocular melanoma. Within four years post-treatment, however, the majority of patients experience some visual loss due to radiation retinopathy. The high incidence of late complications suggests that careful treatment optimization may lead to improved outcome. The goal of optimization would be to reduce the magnitude of vision-limiting complications without compromising tumor control. We have developed a three-dimensional computer model for ophthalmic plaque therapy which permits us to explore the potential of various optimization strategies. One simple strategy which shows promise is to maximize the ratio of dose to the tumor apex (T) compared to dose to the macula (M). By modifying the parameters of source location, activity distribution, source orientation, and shielding we find that the calculated T:M ratio can be varied by a factor of 2 for a common plaque design and posterior tumor location. Margins and dose to the tumor volume remain essentially unchanged

  16. Clinical quality assurance for 106Ru ophthalmic applicators

    International Nuclear Information System (INIS)

    Background and purpose: Episcleral brachytherapy using 106Ru/106Rh ophthalmic applicators is a proven method of therapy of uveal melanomas sparing the globe and in many cases sparing the vision. In the year 2001, an internal clinical quality assurance procedure revealed that part of the ophthalmic applicators leaked and that the calibration was erroneous. Consequently, the producer modernized its production procedures and, in May 2002, introduced a dose rate calibration that is traceable to the NIST standard. This NIST calibration confirmed that the previous calibration had been incorrect. In order to study the effects of the producer's new internal quality assurance procedures on the ophthalmic applicators, applicators of this new generation were submitted to a newly improved internal clinical acceptance test. Patients and methods: The internal clinical acceptance test consists of a leakage test and a dosimetric test of the ophthalmic applicators. The leakage test simulates contact of the ophthalmic applicators with chloride containing body fluid. The dosimetric tests measure depth dose curves and dose rate with a plastic scintillator dosimetric system and compare them with the indications in the producer's certificate. Furthermore, the depth dose profile of the most frequently used applicator (type CCB) was compared with published data. Results: The internal clinical leakage test showed that all of the tested ophthalmic applicators belonging to the new generation (n=17) were tight and not contaminated. The dosimetric acceptance tests applied to seven different types of applicators revealed that the relative depth dose profiles in the therapeutically relevant range (up to a depth of ≤7 mm) deviate from the producer's indications only by -2.7 to +3.2%. The acceptance test of the dose rate values of the ophthalmic applicators at a distance of 2 mm from the surface of the applicators resulted in a coefficient of variation of 1.7% (n=17). In the evaluation of the

  17. Pixel detector insertion

    CERN Multimedia

    CMS

    2015-01-01

    Insertion of the Pixel Tracker, the 66-million-channel device used to pinpoint the vertex of each colliding proton pair, located at the heart of the detector. The geometry of CMS is a cylinder lying on its side (22 meters long and 15 meters high in dia

  18. The Composite Insertion Electrode

    DEFF Research Database (Denmark)

    Atlung, Sven; Zachau-Christiansen, Birgit; West, Keld;

    1984-01-01

    The specific energy obtainable by discharge of porous insertion electrodes is limited by electrolyte depletion in thepores. This can be overcome using a solid ion conductor as electrolyte. The term "composite" is used to distinguishthese electrodes from porous electrodes with liquid electrolyte...

  19. Inserting the CMS solenoid

    CERN Multimedia

    Maximilien Brice

    2005-01-01

    The huge superconducting solenoid for CMS is inserted into the cryostat barrel. CMS uses the world's largest thin solenoid, in terms of energy stored, and is 12 m long, with a diameter of 6 m and weighing 220 tonnes. When turned on the magnet will produce a field strength of 4 T using superconducting niobium-titanium material at 4.5 K.

  20. OPHTHALMIC DISORDERS AMONG STUDENTS OF SCHOOL FOR THE DEAF

    Directory of Open Access Journals (Sweden)

    Omolase C O

    2012-08-01

    Full Text Available Aim: This study aimed at determining the prevalence and pattern of ophthalmic disorders among students of School for the Deaf, Akure, Ondo State, Nigeria.Methodology: This is a cross sectional descriptive study was conducted in October, 2011 as part of activities marking the Annual Physicians’ week of Nigerian Medical Association (NMA,Ondo State. Ethical clearance was obtained from the Ethical Review Committee of Federal Medical Centre, Owo prior to commencement of this study. The permission of the School Authority was also obtained before the commencement of this study. The respondents were selected by simple random sampling technique. All enrolled participants were interviewed with the aid of the study instrument (questionnaire by the authors and interpreters (school teachers.Results: The respondents comprised of 91(56.9% Males and 69 Females (43.1%. Nearly all the respondents;158(98.8% were deaf and dumb. Most respondents; 116(72.5% had ocular examination in the past. Few respondents; 118(73.75% had ophthalmic disorder. The commonest ophthalmic disorder was refractive error which was found in 16 respondents (38.1%. Myopia was diagnosed in 9 respondents.CONCLUSION: Most of the respondents were deaf and dumb. Few respondents had ophthalmic disorder. The commonest ophthalmic disorder was refractive error. Myopia was the most predominant refractive error. There is need for periodic ocular screening and treatment atthe School for the Deaf.

  1. 21 CFR 524.1484e - Neomycin sulfate and polymyxin B sulfate ophthalmic solution.

    Science.gov (United States)

    2010-04-01

    ... ophthalmic solution. 524.1484e Section 524.1484e Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS OPHTHALMIC AND TOPICAL DOSAGE FORM NEW ANIMAL DRUGS § 524.1484e Neomycin sulfate and polymyxin B sulfate ophthalmic solution....

  2. 21 CFR 524.390d - Chloramphenicol-prednisolone ophthalmic ointment.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Chloramphenicol-prednisolone ophthalmic ointment... SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS OPHTHALMIC AND TOPICAL DOSAGE FORM NEW ANIMAL DRUGS § 524.390d Chloramphenicol-prednisolone ophthalmic ointment. (a) Specifications. Each...

  3. 21 CFR 524.1880 - Prednisolone-neomycin sulfate ophthalmic ointment.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Prednisolone-neomycin sulfate ophthalmic ointment... SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS OPHTHALMIC AND TOPICAL DOSAGE FORM NEW ANIMAL DRUGS § 524.1880 Prednisolone-neomycin sulfate ophthalmic ointment. (a)...

  4. 21 CFR 524.1600b - Nystatin, neomycin, thiostrepton, and triamcinolone acetonide ophthalmic ointment.

    Science.gov (United States)

    2010-04-01

    ... triamcinolone acetonide ophthalmic ointment. 524.1600b Section 524.1600b Food and Drugs FOOD AND DRUG... OPHTHALMIC AND TOPICAL DOSAGE FORM NEW ANIMAL DRUGS § 524.1600b Nystatin, neomycin, thiostrepton, and triamcinolone acetonide ophthalmic ointment. (a) Specifications. Each cubic centimeter of ointment contains:...

  5. 10 CFR 35.433 - Decay of strontium-90 sources for ophthalmic treatments.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Decay of strontium-90 sources for ophthalmic treatments... Brachytherapy § 35.433 Decay of strontium-90 sources for ophthalmic treatments. (a) Only an authorized medical... times for ophthalmic treatments. The decay must be based on the activity determined under § 35.432....

  6. Photoresponsive Cellulose Nanocrystals

    Directory of Open Access Journals (Sweden)

    Dimitris S Argyropoulos

    2011-07-01

    Full Text Available In this communication a method for the creation of fluorescent cellulose nanoparticles using click chemistry and subsequent photodimerization of the installed side‐ chains is demonstrated. In the first step, the primary hydroxyl groups on the surface of the CNCs were converted to carboxylic acids by using TEMPO‐mediated hypohalite oxidation. The alkyne groups, essential for the click reaction, were introduced into the surface of TEMPO‐ oxidized CNCs via carbodiimide‐mediated formation of an amide linkage between monomers carrying an amine functionality and carboxylic acid groups on the surface of the TEMPO‐oxidized CNCs. Finally, the reaction of surface‐modified TEMPO‐oxidized cellulose nanocrystals and azido‐bearing coumarin and anthracene monomers were carried out by means of a click chemistry, i.e., Copper(I‐catalyzed Azide‐Alkyne Cycloaddition (CuAAC to produce highly photo‐responsive and fluorescent cellulose nanoparticles. Most significantly, the installed coumarin and/or anthracene side‐chains were shown to undergo UV‐induced [2+2] and [4+4] cycloaddition reactions, bringing and locking the cellulose nanocrystals together. This effort paves the way towards creating, cellulosic photo responsive nano‐arrays with the potential of photo reversibility since these reactions are known to be reversible at varying wavelengths.

  7. Formulation evaluation and validation of ophthalmic emulsion of docosahexaenoic acid

    OpenAIRE

    R. R. Nikhade; Deshpande, S A

    2014-01-01

    The present study aimed at the formulation evaluation and validation of ophthalmic emulsion of docosahexaenoic acid for ophthalmic delivery of drug. Preparation of oil-in-water (o/w) type emulsion is one of the approaches to formulate drugs that are poorly water-soluble. When DHA is administered in  capsule dosage form then less amount of drug reaches to the site of inflammation in the eye hence more dose is required, still the inflammation is at risk. Hence, for the direct application of DHA...

  8. Ophthalmic and visual profile of guide dog owners in Scotland

    OpenAIRE

    Refson, K; Jackson, A; Dusoir, A; Archer, D.

    1999-01-01

    BACKGROUND/AIMS—Out of an estimated 90 000 visually impaired people in Scotland, 509 make use of a guide dog. Initial research in Northern Ireland suggests that the ophthalmic profile of guide dog owners (GDOs) is highly specific. The aim of this study was to compare the ophthalmic and visual characteristics of Scottish GDOs with other groups of visually impaired people.
METHODS—A random sample of GDOs from central and northern Scotland (n=82) underwent a detailed assessment of residual visio...

  9. The cellulose resource matrix.

    Science.gov (United States)

    Keijsers, Edwin R P; Yılmaz, Gülden; van Dam, Jan E G

    2013-03-01

    The emerging biobased economy is causing shifts from mineral fossil oil based resources towards renewable resources. Because of market mechanisms, current and new industries utilising renewable commodities, will attempt to secure their supply of resources. Cellulose is among these commodities, where large scale competition can be expected and already is observed for the traditional industries such as the paper industry. Cellulose and lignocellulosic raw materials (like wood and non-wood fibre crops) are being utilised in many industrial sectors. Due to the initiated transition towards biobased economy, these raw materials are intensively investigated also for new applications such as 2nd generation biofuels and 'green' chemicals and materials production (Clark, 2007; Lange, 2007; Petrus & Noordermeer, 2006; Ragauskas et al., 2006; Regalbuto, 2009). As lignocellulosic raw materials are available in variable quantities and qualities, unnecessary competition can be avoided via the choice of suitable raw materials for a target application. For example, utilisation of cellulose as carbohydrate source for ethanol production (Kabir Kazi et al., 2010) avoids the discussed competition with easier digestible carbohydrates (sugars, starch) deprived from the food supply chain. Also for cellulose use as a biopolymer several different competing markets can be distinguished. It is clear that these applications and markets will be influenced by large volume shifts. The world will have to reckon with the increase of competition and feedstock shortage (land use/biodiversity) (van Dam, de Klerk-Engels, Struik, & Rabbinge, 2005). It is of interest - in the context of sustainable development of the bioeconomy - to categorize the already available and emerging lignocellulosic resources in a matrix structure. When composing such "cellulose resource matrix" attention should be given to the quality aspects as well as to the available quantities and practical possibilities of processing the

  10. Electrochemical synthesis of cellulose mesylate

    Science.gov (United States)

    Khidirov, Sh Sh; Akhmedov, M. A.; Khibiev, H. S.

    2016-04-01

    The article deal with the possibility anode modification of cellulose to form its ester - mesylate by voltametric measurement method and preparative electrosynthesis on a platinum electrode in the system cellulose - dimethyl sulfoxide - methanesulfonic

  11. Structure of cellulose acetobacter xylinum

    International Nuclear Information System (INIS)

    The data are presented on optimization of cellulose synthesis by Acetobacter xylinum (strain VKM V-880) and the structural characteristics of A. xylinum cellulose gel film synthesized during static cultivation. The structural changes caused by the removal of water from gel films are established and the structural organization of macromolecular chains in cellulose A. xylinum is studied

  12. Cellulose Microfibril Formation by Surface-Tethered Cellulose Synthase Enzymes.

    Science.gov (United States)

    Basu, Snehasish; Omadjela, Okako; Gaddes, David; Tadigadapa, Srinivas; Zimmer, Jochen; Catchmark, Jeffrey M

    2016-02-23

    Cellulose microfibrils are pseudocrystalline arrays of cellulose chains that are synthesized by cellulose synthases. The enzymes are organized into large membrane-embedded complexes in which each enzyme likely synthesizes and secretes a β-(1→4) glucan. The relationship between the organization of the enzymes in these complexes and cellulose crystallization has not been explored. To better understand this relationship, we used atomic force microscopy to visualize cellulose microfibril formation from nickel-film-immobilized bacterial cellulose synthase enzymes (BcsA-Bs), which in standard solution only form amorphous cellulose from monomeric BcsA-B complexes. Fourier transform infrared spectroscopy and X-ray diffraction techniques show that surface-tethered BcsA-Bs synthesize highly crystalline cellulose II in the presence of UDP-Glc, the allosteric activator cyclic-di-GMP, as well as magnesium. The cellulose II cross section/diameter and the crystal size and crystallinity depend on the surface density of tethered enzymes as well as the overall concentration of substrates. Our results provide the correlation between cellulose microfibril formation and the spatial organization of cellulose synthases. PMID:26799780

  13. CHARACTERIZATION OF REGENERATED CELLULOSE MEMBRANES HYDROLYZED FROM CELLULOSE ACETATE

    Institute of Scientific and Technical Information of China (English)

    Yun Chen; Xiao-peng Xiong; Guang Yang; Li-na Zhang; Sen-lin Lei; Hui Lianga

    2002-01-01

    A series of cellulose acetate membranes were prepared by using formamide as additive, and then were hydrolyzedin 4 wt% aqueous NaOH solution for 8 h to obtain regenerated cellulose membranes. The dependence of degree ofsubstitution, structure, porous properties, solubility and thermal stability on hydrolysis time was studied by chemical titration,Fourier transform infrared spectroscopy, scanning electron microscopy, wide-angle X-ray diffraction, and differentialscanning calorimetry, respectively. The results indicated that the pore size of the regenerated cellulose membranes wasslightly smaller than that of cellulose acetate membrane, while solvent-resistance, crystallinity and thermostability weresignificantly improved. This work provides a simple way to prepare the porous cellulose membranes, which not only kept thegood pore characteristics of cellulose acetate membranes, but also possessed solvent-resistance, high crystallinity andthermostability. Therefore, the application range of cellulose acetate membranes can be expanded.

  14. Degradation of cellulose in irradiated wood and purified celluloses

    International Nuclear Information System (INIS)

    The degradation of cellulose chains in Pinus radiata and Eucalyptus regnans given small gamma-radiation doses has been studied. Scission yields showed marked dose-dependency effects, of which some appear to be due to an inherent dose-dependency exhibited by cellulose itself, and others indicate a protective action of some natural wood constituents. A uniform treatment of viscometry data reported by various workers who have studied radiation-induced degradation of purified cellulose materials, has been used to enable their scission results to be compared with each other and with those for natural wood cellulose of various dose levels. Generally, cellulose in wood is less degraded by radiation than is purified cellulose. However, with Eucalyptus regnans remarkably high scission yields, significantly higher than expected for purified cellulose, were observed at dose levels of 0.5-1.0 x 104Gy. The relevance of these results to changes in pulp yield following irradiation of wood chips, is briefly discussed. (author)

  15. The cellulose resource matrix

    NARCIS (Netherlands)

    Keijsers, E.R.P.; Yilmaz, G.; Dam, van J.E.G.

    2013-01-01

    The emerging biobased economy is causing shifts from mineral fossil oil based resources towards renewable resources. Because of market mechanisms, current and new industries utilising renewable commodities, will attempt to secure their supply of resources. Cellulose is among these commodities, where

  16. Cysticercosis cellulose cutis

    Directory of Open Access Journals (Sweden)

    Inamadar Arun

    2001-01-01

    Full Text Available A woman aged 30 years with solitary lesion of cysticercosis cellulose cutis is reported. Cutaneous cysticerci are often a pointer to the involvement of internal organs. Our patient was a pure vegetarian so, probable mode of infection may be ingestion of contaminated vegetables, where the practice of using pig feces as manure is prevalent.

  17. Derivatives of Oxidized Cellulose

    Czech Academy of Sciences Publication Activity Database

    Taubner, T.; Sobek, Jiří; Havelka, P.; Kvasnička, F.; Synytsya, A.; Čopíková, J.

    Praha : Česká společnost chemická, 2009, s. 777. ISSN 0009-2770. [International Conference on Polysaccharides-Glycoscience 2009 /5./. Praha (CZ), 11.11.2009-13.11.2009] Institutional research plan: CEZ:AV0Z40720504 Keywords : cellulose * reaction progress * chromatography Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  18. 21 CFR 524.1200b - Kanamycin ophthalmic aqueous solution.

    Science.gov (United States)

    2010-04-01

    ... (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS OPHTHALMIC AND TOPICAL DOSAGE FORM NEW ANIMAL DRUGS...) of this chapter. (c) Conditions of use. It is indicated for use in dogs in various eye infections due..., removal of foreign bodies, and intraocular surgery. Instill a few drops into the affected eye every...

  19. Intraorbital ophthalmic artery aneurysm associated with basilar tip saccular aneurysm

    Energy Technology Data Exchange (ETDEWEB)

    Dehdashti, A.R.; Tribolet, N. de [Department of Neurosurgery, HUG, Geneva (Switzerland); Safran, A.B. [Department of Ophthalmology, HUG, Geneva (Switzerland); Martin, J.B.; Ruefenacht, D.A. [Division of Neuroradiology, HUG, Geneva (Switzerland)

    2002-07-01

    We present a rare case of intraorbital ophthalmic artery aneurysm found incidentally, together with a ruptured aneurysm of the tip of the basilar artery. The intraorbital aneurysm was asymptomatic, and no treatment was offered. Angiographic control was recommended to detect any progression. Treatment may be indicated for documented enlargement or significant mass effect of the aneurysm. (orig.)

  20. Intraorbital ophthalmic artery aneurysm associated with basilar tip saccular aneurysm

    International Nuclear Information System (INIS)

    We present a rare case of intraorbital ophthalmic artery aneurysm found incidentally, together with a ruptured aneurysm of the tip of the basilar artery. The intraorbital aneurysm was asymptomatic, and no treatment was offered. Angiographic control was recommended to detect any progression. Treatment may be indicated for documented enlargement or significant mass effect of the aneurysm. (orig.)

  1. Numerical implementation of generalized Coddington equations for ophthalmic lens design

    Science.gov (United States)

    Rojo, P.; Royo, S.; Ramírez, J.; Madariaga, I.

    2014-02-01

    A method for general implementation in any software platform of the generalized Coddington equations is presented, developed, and validated within a Matlab environment. The ophthalmic lens design strategy is presented thoroughly, and the basic concepts of generalized ray tracing are introduced. The methodology for ray tracing is shown to include two inter-related processes. Firstly, finite ray tracing is used to provide the main direction of propagation of the considered ray at the incidence point of interest. Afterwards, generalized ray tracing provides the principal curvatures of the local wavefront at that point, and its orientation after being refracted by the lens. The curvature values of the local wavefront are interpreted as the sagital and tangential powers of the lens at the point of interest. The proposed approach is validated using a double-check of the calculated lens performance in the spherical lens case: while finite ray tracing is validated using a commercial ray tracing software, generalized ray tracing is validated using a software application for ophthalmic lens design based on the classical version of Coddington equations. Equations of the complete tracing process are developed in detail for the case of generic astigmatic ophthalmic lenses as an example. Three-dimensional representation of the sagital and tangential powers of the ophthalmic lens at all directions of gaze then becomes possible, and results are presented for lenses with different geometries.

  2. Exposure Limits in Ophthalmic Imaging with Scanning Laser Ophthalmoscopes

    International Nuclear Information System (INIS)

    We present an analysis of the exposure to laser radiation resulting from the use of scanning laser ophthalmoscopes in ophthalmic imaging of the ocular fundus. Exposures limits are determined, based on the IEC/EN 60825-1 standard. These limits are applied on the safety analysis of a commercial scanning laser ophthalmoscope. (author)

  3. ENDOSCOPIC GROMMET INSERTION OUR EXPERIENCE

    Directory of Open Access Journals (Sweden)

    Balasubramanian Thiagarajan

    2012-03-01

    Full Text Available Grommet insertion the commonest surgical procedure next only to circumcision is usually performed using an operating microscope 1. Authors have been using 4 mm 0 degree nasalendoscopes to perform this procedure during the last 5 years. This is a report of their experience in using endoscope inlieu of microscope in performing this surgery. This study makes a comparative analysis of Endoscopic Grommet insertion viz a viz Microscopic Grommet insertion. For this comparative analysis one year (2009 data base of Government Stanley Medical College Chennai India was used. This study reveals that Endoscopic Grommet insertion compared favorably with Microscopic Grommet insertion in all aspects with certain obvious advantages.

  4. Synthesis and characterization of cellulose derivatives obtained from bacterial cellulose

    International Nuclear Information System (INIS)

    The chemical modification of cellulose leads to production of derivatives with different properties from those observed for the original cellulose, for example, increased solubility in more traditional solvents. In this work we synthesized four derivatives of cellulose: microcrystalline cellulose, cellulose acetate, methylcellulose and carboxymethylcellulose using bacterial cellulose as a source. These were characterized in terms of chemical and structural changes by examining the degree of substitution (DS), infrared spectroscopy (FTIR) and nuclear magnetic resonance spectroscopy - NMR 13C. The molecular weight and degree of polymerization were evaluated by viscometry. The characterization of the morphology of materials and thermal properties were performed with the techniques of X-ray diffraction, electron microscopy images, differential scanning calorimetry (DSC) and thermogravimetric analysis. (author)

  5. Interactions of microfibrillated cellulose and cellulosic fines with cationic polyelectrolytes

    OpenAIRE

    Taipale, Tero

    2010-01-01

    The overall aim of this work was to produce and characterize different types of cellulosic fines and microfibrillated cellulose; to study their interactions with high molar mass cationic polyelectrolytes; and to demonstrate novel examples of their utilization. The work was performed, and its results discussed mainly from papermaking point of view, but the results are also well applicable in other fields of industry. Cellulosic fines are an essential component of papermaking fiber suspens...

  6. Facility target insert shielding assessment

    Energy Technology Data Exchange (ETDEWEB)

    Mocko, Michal [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-10-06

    Main objective of this report is to assess the basic shielding requirements for the vertical target insert and retrieval port. We used the baseline design for the vertical target insert in our calculations. The insert sits in the 12”-diameter cylindrical shaft extending from the service alley in the top floor of the facility all the way down to the target location. The target retrieval mechanism is a long rod with the target assembly attached and running the entire length of the vertical shaft. The insert also houses the helium cooling supply and return lines each with 2” diameter. In the present study we focused on calculating the neutron and photon dose rate fields on top of the target insert/retrieval mechanism in the service alley. Additionally, we studied a few prototypical configurations of the shielding layers in the vertical insert as well as on the top.

  7. Novel oil resistant cellulosic materials

    OpenAIRE

    Aulin, Christian

    2009-01-01

    The aim of this study has been to prepare and characterise oil resistant cellulosic materials, ranging from model surfaces to papers and aerogels. The cellulosic materials were made oil resistant by chemical and topographic modifications, based on surface energy, surface roughness and barrier approaches. Detailed wetting studies of the prepared cellulosic materials were made using contact angle measurements and standardised penetration tests with different alkanes and oil mixtures. A signific...

  8. Endoscopic grommet insertion our experience

    OpenAIRE

    Balasubramanian Thiagarajan; Venkatesan Ulaganathan; Seethalakshmi Narashiman

    2012-01-01

    Grommet insertion the commonest surgical procedure next only to circumcision is usually performed using an operating microscope 1. Authors have been using 4 mm 0 degree nasal endoscopes to perform this procedure during the last 5 years. This is a report of their experience in using endoscope inlieu of microscope in performing this surgery. This study makes a comparative analysis of Endoscopic Grommet insertion viz a viz Microscopic Grommet insertion. For this comparative analysis one year (20...

  9. Subjective Misidentification and Thought Insertion

    OpenAIRE

    Parrott, Matthew Thomas

    2015-01-01

    This essay presents a new account of thought insertion. Prevailing views in both philosophy and cognitive science tend to characterize the experience of thought insertion as missing or lacking some element, such as a ‘sense of agency’, found in ordinary first-person awareness of one’s own thoughts. By contrast, I propose that, rather than lacking something, experiences of thought insertion have an additional feature not present in ordinary conscious experiences of one’s own thoughts. More spe...

  10. Triple A syndrome with ophthalmic manifestations in two siblings

    Directory of Open Access Journals (Sweden)

    Babu Kalpana

    2007-01-01

    Full Text Available Triple A syndrome (Allgrove syndrome is a rare, autosomal recessive disorder characterized by adrenocorticotropic hormone resistant adrenal insufficiency, alacrima, achalasia of the esophageal cardia, progressive neurological degeneration and occasionally autonomic instability. We report the ophthalmic manifestations in 2 siblings from a consanguineous family with this syndrome. A routine ophthalmic examination showed absence of palpebral portion of lacrimal gland, dry eyes and sluggish pupillary reflexes in both eyes of these patients. Both of these patients had achalasia cardia while the boy additionally had increased serum cortisol levels. Topical ocular lubricants were prescribed for both of them and Heller′s cardiomyotomy with fundus plication was done for achalasia. These cases would create an awareness of this rare condition in ophthalmology in addition to suggesting its management.

  11. Hydrogel Contact Lens for Extended Delivery of Ophthalmic Drugs

    Directory of Open Access Journals (Sweden)

    Xiaohong Hu

    2011-01-01

    Full Text Available Soft contact lenses can improve the bioavailability and prolong the residence time of drugs and, therefore, are ideal drug carriers for ophthalmic drug delivery. Hydrogels are the leading materials of soft contact lenses because of their biocompatibility and transparent characteristic. In order to increase the amount of load drug and to control their release at the expected intervals, many strategies are developed to modify the conventional contact lens as well as the novel hydrogel contact lenses that include (i polymeric hydrogels with controlled hydrophilic/hydrophobic copolymer ratio; (ii hydrogels for inclusion of drugs in a colloidal structure dispersed in the contact lenses; (iii ligand-containing hydrogels; (iv molecularly imprinted polymeric hydrogels; (v hydrogel with the surface containing multilayer structure for drugs loading and releasing. The advantages and disadvantages of these strategies in modifying or designing hydrogel contact lenses for extended ophthalmic drug delivery are analyzed in this paper.

  12. The efficacy of acetone in the sterilisation of ophthalmic instruments

    Directory of Open Access Journals (Sweden)

    Agrawal Vinay

    1993-01-01

    Full Text Available Acetone has been considered a quick, effective and less expensive chemical sterilising agent and continues to be used by ophthalmic surgeons, at least in developing countries. Its utility however has been questioned recently. This study was designed to assess the efficacy of acetone against Pseudomonas aeruginosa, Bacillus subtilis and Aspergillus flavus present on ophthalmic surgical instruments (forceps, sutures. The instruments were contaminated by immersion in standard suspensions of the organisms and thereafter were either unwashed (group-I, washed and dried (group-II or only washed (group-III before immersion in acetone. The exposure to acetone was kept at 3, 10 and 20 minutes in each group. The results showed that acetone could eliminate Pseudomonas (vegetative bacteria after 10 minutes exposure in unwashed group and 3 minutes exposure in washed groups. It was ineffective against spore bearing bacteria (B. subtilis and fungus (Aspergillus flavus even after 20 minutes of exposure

  13. Blindness resulting from orbital complications of ophthalmic zoster.

    Science.gov (United States)

    Moniuszko, Anna; Sosnowska, Magdalena; Zajkowska, Agata; Garkowski, Adam; Czupryna, Piotr; Pancewicz, Sławomir; Zajkowska, Joanna

    2015-10-01

    Herpes zoster ophthalmicus occurs when the latent varicella zoster virus (VZV) reactivates in the trigeminal ganglion and ophthalmic branch of the trigeminal nerve. In the elderly, there is a sharp increase in the tendency of secondary skin bacterial infections occurrence due to the deterioration of capabilities of self-care and changed sanitation. We present a case of patient who developed phlegmon of the orbit, which resulted with complete unilateral blindness. Varicella zoster virus infection in the elderly may have a severe course due to the progressive weakening of the immune system related to the age. Moreover, skin lesions around the eye socket require special care in prevention of bacterial superinfections due to the extremely high risk of life-threatening complications or disability. Neuralgia resistant to pharmacological treatment present in the course of ophthalmic zoster and difficulty in caring about skin lesions predispose to the occurrence of complications. PMID:26759550

  14. Superselective ophthalmic intraarterial thrombolysis for central retinal artery thrombosis

    International Nuclear Information System (INIS)

    Objective: To investigate the effect of superselective ophthalmic artery thrombolysis for treatment of central retinal artery (CRAT). Methods: 250000-500000 u urokinase was directly perfused via ophthalmic artery (OA) through the retained superselective catheter after angiography into 8 eyes of 8 patients with CRAT. Results: The visual acuity (VA) was significantly improved in 4 eyes. the VA of 3 eyes reached 0.1-0.3 after 6 months follow-up. the other 3 eyes achieved no significant improvement of VA. The VA of 1 eye decreased from finger count (FC) to light perception (LP). Conclusions: Early diagnosis and early superselective trans-micro catheter thrombolysis would be more effective than traditional treatment. (authors)

  15. A new human eye model for ophthalmic brachytherapy dosimetry

    International Nuclear Information System (INIS)

    The present work proposes a new mathematical eye model for ophthalmic brachytherapy dosimetry. This new model includes detailed description of internal structures that were not treated in previous works, allowing dose determination in different regions of the eye for a more adequate clinical analysis. Dose calculations were determined with the MCNP-4C Monte Carlo particle transport code running n parallel environment using PVM. The Amersham CKA4 ophthalmic applicator has been chosen and the depth dose distribution has been determined and compared to those provide by the manufacturer. The results have shown excellent agreement. Besides, absorbed dose values due to both 125I seeds and 60Co plaques were obtained for each one of the different structures which compose the eye model and can give relevant information in eventual clinical analyses. (authors)

  16. Dosimetry of ophthalmic applications using 125I seed sources

    International Nuclear Information System (INIS)

    Intraocular melanoma is the most common primary malignancy of the eye and radiation therapy using ophthalmic plaque has proved successful for its management. The dose prescription point recommended for 125I eye plaque therapy is usually 5 mm from tumour base centre for tumours with 5 mm or less height and tumour apex, otherwise. A computational programme was written to generate data for the dosimetry of eye plaque therapy using 125I seeds. Variation of central axis depth dose and isodose distributions at reference depth have been studied for different diameter plaques. The reference dose rate chosen for a clinical application, based on treatment planning software, was compared with that derived from the data generated in the present study. The dosimetry data generated and presented in this paper will help pre-planning of ophthalmic applications, using 125I seeds. (author)

  17. Cellulose biogenesis in Dictyostelium discoideum

    Energy Technology Data Exchange (ETDEWEB)

    Blanton, R.L.

    1993-12-31

    Organisms that synthesize cellulose can be found amongst the bacteria, protistans, fungi, and animals, but it is in plants that the importance of cellulose in function (as the major structural constituent of plant cell walls) and economic use (as wood and fiber) can be best appreciated. The structure of cellulose and its biosynthesis have been the subjects of intense investigation. One of the most important insights gained from these studies is that the synthesis of cellulose by living organisms involves much more than simply the polymerization of glucose into a (1{r_arrow}4)-{beta}-linked polymer. The number of glucoses in a polymer (the degree of polymerization), the crystalline form assumed by the glucan chains when they crystallize to form a microfibril, and the dimensions and orientation of the microfibrils are all subject to cellular control. Instead of cellulose biosynthesis, a more appropriate term might be cellulose biogenesis, to emphasize the involvement of cellular structures and mechanisms in controlling polymerization and directing crystallization and deposition. Dictyostelium discoideum is uniquely suitable for the study of cellulose biogenesis because of its amenability to experimental study and manipulation and the extent of our knowledge of its basic cellular mechanisms (as will be evident from the rest of this volume). In this chapter, I will summarize what is known about cellulose biogenesis in D. discoideum, emphasizing its potential to illuminate our understanding both of D. discoideum development and plant cellulose biogenesis.

  18. Post-CTS Delay Insertion

    OpenAIRE

    Jianchao Lu; Baris Taskin

    2010-01-01

    A post-clock-tree-synthesis (post-CTS) optimization method is proposed that suggests delay insertion at the leaves of the clock tree in order to implement a limited version of clock skew scheduling. Delay insertion is limited on each clock tree branch simultaneous with a global monitoring of the total amount of delay insertion. The delay insertion for nonzero clock skew operation is performed only at the clock sinks in order to preserve the structure and the optimizations implemented in the c...

  19. IMPORTANCE OF MEDICAL AUDIT IN A COMMUNITY OPHTHALMIC OUTREACH PROGRAM

    OpenAIRE

    Shubhangi Prashant; Sharmil

    2014-01-01

    Outreach delivery of health care is an important part of Community ophthalmology, especially for Cataract patients. Quality assurance in such programmes, which guarantees every patient of best possible outcomes and fewest possible complications in such programmes of key importance. OBJECTIVES: To study the importance of medical audit in assessing & assuring the quality of surgical services provided to the patients in community ophthalmic outreach programmes. STUDY DESIGN: ...

  20. Microgravity-Induced Fluid Shift and Ophthalmic Changes

    OpenAIRE

    Emily S. Nelson; Lealem Mulugeta; Myers, Jerry G

    2014-01-01

    Although changes to visual acuity in spaceflight have been observed in some astronauts since the early days of the space program, the impact to the crew was considered minor. Since that time, missions to the International Space Station have extended the typical duration of time spent in microgravity from a few days or weeks to many months. This has been accompanied by the emergence of a variety of ophthalmic pathologies in a significant proportion of long-duration crewmembers, including globe...

  1. Designing a program for ophthalmic registered nurse first assistants.

    Science.gov (United States)

    Karger, E A

    1995-10-01

    Insurance companies eliminated payment for physician first assistants in cataract surgery. Community hospitals are responding to this situation by utilizing perioperative nurses and certified surgical technicians. The credentialing process is largely relegated to each hospital. The ophthalmic nurse is now quite pivotal in writing the policies and procedures. Also inherent in this expanded role is the development of preceptor training, job description and performance appraisals. This serves as a primer to specifically address these problems in a community hospital operating room. PMID:7594911

  2. Clinical utility of voriconazole eye drops in ophthalmic fungal keratitis

    OpenAIRE

    Daoud Al-Badriyeh; Chin Fen Neoh; Kay Stewart; et al.

    2010-01-01

    Daoud Al-Badriyeh, Chin Fen Neoh, Kay Stewart, David CM KongCentre for Medicine Use and Safety, Faculty of Pharmacy and Pharmaceutical Sciences, Monash University, Victoria, AustraliaAbstract: Fungal keratitis is one of the major causes of ophthalmic mycosis and is difficult to treat. The range of common antifungal agents available for fungal keratitis remains inadequate and is generally associated with poor clinical outcomes. Voriconazole is a new generation triazole antifungal agent. Only m...

  3. OPHTHALMIC DISORDERS AMONG STUDENTS OF SCHOOL FOR THE DEAF

    OpenAIRE

    Omolase C O; Komolafe O O; Adeniji A O

    2012-01-01

    Aim: This study aimed at determining the prevalence and pattern of ophthalmic disorders among students of School for the Deaf, Akure, Ondo State, Nigeria.Methodology: This is a cross sectional descriptive study was conducted in October, 2011 as part of activities marking the Annual Physicians’ week of Nigerian Medical Association (NMA),Ondo State. Ethical clearance was obtained from the Ethical Review Committee of Federal Medical Centre, Owo prior to commencement of this study. The permission...

  4. Dual-thread parallel control strategy for ophthalmic adaptive optics

    OpenAIRE

    Yu, Yongxin; Zhang, Yuhua

    2014-01-01

    To improve ophthalmic adaptive optics speed and compensate for ocular wavefront aberration of high temporal frequency, the adaptive optics wavefront correction has been implemented with a control scheme including 2 parallel threads; one is dedicated to wavefront detection and the other conducts wavefront reconstruction and compensation. With a custom Shack-Hartmann wavefront sensor that measures the ocular wave aberration with 193 subapertures across the pupil, adaptive optics has achieved a ...

  5. Blindness resulting from orbital complications of ophthalmic zoster

    OpenAIRE

    Moniuszko, Anna; Sosnowska, Magdalena; Zajkowska, Agata; Garkowski, Adam; Czupryna, Piotr; Pancewicz, Sławomir; Zajkowska, Joanna

    2015-01-01

    Herpes zoster ophthalmicus occurs when the latent varicella zoster virus (VZV) reactivates in the trigeminal ganglion and ophthalmic branch of the trigeminal nerve. In the elderly, there is a sharp increase in the tendency of secondary skin bacterial infections occurrence due to the deterioration of capabilities of self-care and changed sanitation. We present a case of patient who developed phlegmon of the orbit, which resulted with complete unilateral blindness. Varicella zoster virus infect...

  6. Ophthalmic Morbidity in School Children in Hilly Areas of Uttarakhand

    Directory of Open Access Journals (Sweden)

    Surekha Kishore

    2014-03-01

    Full Text Available Introduction: School children constitute about one fourth of population of India. Early detection and treatment of various eye diseases helps in avoiding many complications. The magnitude of blindness is 3-4 times greater in developing countries. Very few studies have been conducted in Uttarakhand revealing the ophthalmic morbidity in school children or general population. Hilly areas especially the remote ones face various problems like, poor transportation facilities, distant health facilities, use of traditional methods for treatment, faith healing, customs and belief system, lack of information.  Moreover   water supply, poor personal hygiene and other factors also add up to these problems. Aim: To study the ophthalmic morbidities in school children in 3 schools of Thatyur block. Methodology: It was a cross sectional study. Result: A total of 705 students were enrolled. Permission from school authorities was seeked before the start of study. Schools were visited twice in a week current and preliminary information was taken from the students & teacher regarding education, occupation, income etc. General examination and ophthalmic examination was done with day & torch light along with refraction, with the help of standard Snellen’s chart. Each eye was examined separately. A vision of 6/6 was considered as normal. Near vision was tested with new vision Snellen’s chart at 12-14 inches away from eye.

  7. Studies on characteristics of dosimetry for 125I ophthalmic applicator

    International Nuclear Information System (INIS)

    Isodose curves for 125I ophthalmic application in different geometry and activity can be obtained using the empirical formula based on suitable geometric model. The results of surface dose rate determined with lithium fluoride (LiF) thermoluminescent dosimeter (TLD's) chips in water-organic glass phantom and air had no obvious difference and the surface dose rate and its uniformity, (3.46 +- 0.011) and (0.178 +- 0.15) nGy/h·107Bq were obtained. Count measurements and dose determinations for the front and back etc. of the ophthalmic applicator with BaF2 scintillation detector and LiF TLD's had revealed the space distribution of dose for 125I ophthalmic applicator in which dose on the back was less than 0.1% of that on the front. The distribution of the absorbed dose rate along the eye axis had been measured using LiF TLD's in water-organic glass phantom. The measured and calculated dose data indicated that when measuring distances were larger than about 5 mm the experimental results agreed with those from calculation within the range of error, otherwise the measured values were lower, still it could be explained by experimental conditions

  8. Salvage/Adjuvant Brachytherapy After Ophthalmic Artery Chemosurgery for Intraocular Retinoblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Francis, Jasmine H., E-mail: francij1@mskcc.org [Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Barker, Christopher A.; Wolden, Suzanne L.; McCormick, Beryl; Segal, Kira; Cohen, Gil [Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Gobin, Y. Pierre; Marr, Brian P. [Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Weill-Cornell Medical College, New York-Presbyterian Hospital, New York, New York (United States); Brodie, Scott E. [Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Mount Sinai School of Medicine, New York, New York (United States); Dunkel, Ira J.; Abramson, David H. [Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Weill-Cornell Medical College, New York-Presbyterian Hospital, New York, New York (United States)

    2013-11-01

    Purpose: To evaluate the efficacy and toxicity of brachytherapy after ophthalmic artery chemosurgery (OAC) for retinoblastoma. Methods and Materials: This was a single-arm, retrospective study of 15 eyes in 15 patients treated with OAC followed by brachytherapy at (blinded institution) between May 1, 2006, and December 31, 2012, with a median 19 months' follow-up from plaque insertion. Outcome measurements included patient and ocular survival, visual function, and retinal toxicity measured by electroretinogram (ERG). Results: Brachytherapy was used as adjuvant treatment in 2 eyes and as salvage therapy in 13 eyes of which 12 had localized vitreous seeding. No patients developed metastasis or died of retinoblastoma. The Kaplan-Meier estimate of ocular survival was 79.4% (95% confidence interval 48.7%-92.8%) at 18 months. Three eyes were enucleated, and an additional 6 eyes developed out-of-target volume recurrences, which were controlled with additional treatments. Patients with an ocular complication had a mean interval between last OAC and plaque of 2.5 months (SD 2.3 months), which was statistically less (P=.045) than patients without ocular complication who had a mean interval between last OAC and plaque of 6.5 months (SD 4.4 months). ERG responses from pre- versus postplaque were unchanged or improved in more than half the eyes. Conclusions: Brachytherapy following OAC is effective, even in the presence of vitreous seeding; the majority of eyes maintained stable or improved retinal function following treatment, as assessed by ERG.

  9. Salvage/Adjuvant Brachytherapy After Ophthalmic Artery Chemosurgery for Intraocular Retinoblastoma

    International Nuclear Information System (INIS)

    Purpose: To evaluate the efficacy and toxicity of brachytherapy after ophthalmic artery chemosurgery (OAC) for retinoblastoma. Methods and Materials: This was a single-arm, retrospective study of 15 eyes in 15 patients treated with OAC followed by brachytherapy at (blinded institution) between May 1, 2006, and December 31, 2012, with a median 19 months' follow-up from plaque insertion. Outcome measurements included patient and ocular survival, visual function, and retinal toxicity measured by electroretinogram (ERG). Results: Brachytherapy was used as adjuvant treatment in 2 eyes and as salvage therapy in 13 eyes of which 12 had localized vitreous seeding. No patients developed metastasis or died of retinoblastoma. The Kaplan-Meier estimate of ocular survival was 79.4% (95% confidence interval 48.7%-92.8%) at 18 months. Three eyes were enucleated, and an additional 6 eyes developed out-of-target volume recurrences, which were controlled with additional treatments. Patients with an ocular complication had a mean interval between last OAC and plaque of 2.5 months (SD 2.3 months), which was statistically less (P=.045) than patients without ocular complication who had a mean interval between last OAC and plaque of 6.5 months (SD 4.4 months). ERG responses from pre- versus postplaque were unchanged or improved in more than half the eyes. Conclusions: Brachytherapy following OAC is effective, even in the presence of vitreous seeding; the majority of eyes maintained stable or improved retinal function following treatment, as assessed by ERG

  10. Insertion device vacuum system designs

    International Nuclear Information System (INIS)

    Synchrotron light source insertion device vacuum systems now in operation and systems proposed for the future are reviewed. An overview of insertion devices is given and four generic vacuum chamber designs, transition section design and pumping considerations are discussed. Examples of vacuum chamber systems are presented

  11. ISR Superconducting High luminosity Insertion

    CERN Multimedia

    1981-01-01

    The picture shows two of the eight superconducting quadrupoles of the low-beta insertion at intersection I8.The increase of luminosity produced by this insertion was above a factor 7. At right one can also see the Open- Axial- Field Magnet. The person is Stephan Pichler. See also 7702690X, 8102123, 8010397, 8008332.

  12. Reduction in drop size of ophthalmic topical drop preparations and the impact of treatment

    Directory of Open Access Journals (Sweden)

    Shiva Kumar

    2011-01-01

    Full Text Available In this work we devised a method to create smaller eye drops of the glaucoma medication timolol maleate by altering the dropper tip design and changing the physical properties of the formulation. Most ocular diseases are treated with topical application of eye drops. After instillation of an eye drop, typically, less than 5% of the applied drug penetrates the cornea and reaches the intraocular tissues; the major fraction of the instilled drug is absorbed and enters the systemic circulation. Ophthalmic solutions are available in multidose or single-dose glass/plastic dropper bottles that deliver drops with a volume that ranges from 25 μL to 70 μL (average 40 μL. Because of the low capacity of the precorneal area, the optimal drop volume is about 20 μL; with larger volumes there is the risk of adverse systemic effects due to absorption of the drug via the nasal mucosa. Thus, both from the biopharmaceutical and economic point of view, drops of only 5-15 mL volume should be instilled into the eye. In this present work we devised a method to reduce the size of the drop by inserting a glass capillary tube into the dropper tip and by changing the physical properties of the formulation (by altering the concentration of Tween 80™, i.e., 0.05% and 0.1% of Tween 80™. We measured the drop sizes of the different timolol eye drop formulations available in the market and estimated the yearly cost of the medications. Our timolol maleate formulation with 0.1% concentration of Tween 80™ delivered through the dropper tip with the inserted glass capillary was shown to be better than the other formulations available in the market in terms of ability to deliver smaller drops, meaning that each bottle would last longer and that the yearly cost of treatment would be lower.

  13. ACCESSIBILITY AND CRYSTALLINITY OF CELLULOSE

    Directory of Open Access Journals (Sweden)

    Michael Ioelovich

    2009-08-01

    Full Text Available The accessibility of cellulose samples having various degrees of crystallinity was studied with respect to molecules of water, lower primary alcohols, and lower organic acids. It was found that small water molecules have full access to non-crystalline domains of cellulose (accessibility coefficient α = 1. Molecules of the lowest polar organic liquids (methanol, ethanol, and formic acid have partial access into the non-crystalline domains (α<1, and with increasing diameter of the organic molecules their accessibility to cellulose structure decreases. Accessibility of cellulose samples to molecules of various substances is a linear function of the coefficient α and the content of non-crystalline domains. The relationship between crystallinity (X and accessibility (A of cellulose to molecules of some liquids has been established as A = α (1-X. The water molecules were found to have greater access to cellulose samples than the molecules of the investigated organic liquids. The obtained results permit use of accessibility data to estimate the crystallinity of cellulose, to examine the structural state of non-crystalline domains, and to predict the reactivity of cellulose samples toward some reagents.

  14. TEMPO-oxidized cellulose nanofibers

    Science.gov (United States)

    Isogai, Akira; Saito, Tsuguyuki; Fukuzumi, Hayaka

    2011-01-01

    Native wood celluloses can be converted to individual nanofibers 3-4 nm wide that are at least several microns in length, i.e. with aspect ratios >100, by TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical)-mediated oxidation and successive mild disintegration in water. Preparation methods and fundamental characteristics of TEMPO-oxidized cellulose nanofibers (TOCN) are reviewed in this paper. Significant amounts of C6 carboxylate groups are selectively formed on each cellulose microfibril surface by TEMPO-mediated oxidation without any changes to the original crystallinity (~74%) or crystal width of wood celluloses. Electrostatic repulsion and/or osmotic effects working between anionically-charged cellulose microfibrils, the ζ-potentials of which are approximately -75 mV in water, cause the formation of completely individualized TOCN dispersed in water by gentle mechanical disintegration treatment of TEMPO-oxidized wood cellulose fibers. Self-standing TOCN films are transparent and flexible, with high tensile strengths of 200-300 MPa and elastic moduli of 6-7 GPa. Moreover, TOCN-coated poly(lactic acid) films have extremely low oxygen permeability. The new cellulose-based nanofibers formed by size reduction process of native cellulose fibers by TEMPO-mediated oxidation have potential application as environmentally friendly and new bio-based nanomaterials in high-tech fields.

  15. Cellulose Synthesis in Agrobacterium tumefaciens

    Energy Technology Data Exchange (ETDEWEB)

    Alan R. White; Ann G. Matthysse

    2004-07-31

    We have cloned the celC gene and its homologue from E. coli, yhjM, in an expression vector and expressed the both genes in E. coli; we have determined that the YhjM protein is able to complement in vitro cellulose synthesis by extracts of A. tumefaciens celC mutants, we have purified the YhjM protein product and are currently examining its enzymatic activity; we have examined whole cell extracts of CelC and various other cellulose mutants and wild type bacteria for the presence of cellulose oligomers and cellulose; we have examined the ability of extracts of wild type and cellulose mutants including CelC to incorporate UDP-14C-glucose into cellulose and into water-soluble, ethanol-insoluble oligosaccharides; we have made mutants which synthesize greater amounts of cellulose than the wild type; and we have examined the role of cellulose in the formation of biofilms by A. tumefaciens. In addition we have examined the ability of a putative cellulose synthase gene from the tunicate Ciona savignyi to complement an A. tumefaciens celA mutant. The greatest difference between our knowledge of bacterial cellulose synthesis when we started this project and current knowledge is that in 1999 when we wrote the original grant very few bacteria were known to synthesize cellulose and genes involved in this synthesis were sequenced only from Acetobacter species, A. tumefaciens and Rhizobium leguminosarum. Currently many bacteria are known to synthesize cellulose and genes that may be involved have been sequenced from more than 10 species of bacteria. This additional information has raised the possibility of attempting to use genes from one bacterium to complement mutants in another bacterium. This will enable us to examine the question of which genes are responsible for the three dimensional structure of cellulose (since this differs among bacterial species) and also to examine the interactions between the various proteins required for cellulose synthesis. We have carried out one

  16. Ultrasonic dyeing of cellulose nanofibers.

    Science.gov (United States)

    Khatri, Muzamil; Ahmed, Farooq; Jatoi, Abdul Wahab; Mahar, Rasool Bux; Khatri, Zeeshan; Kim, Ick Soo

    2016-07-01

    Textile dyeing assisted by ultrasonic energy has attained a greater interest in recent years. We report ultrasonic dyeing of nanofibers for the very first time. We chose cellulose nanofibers and dyed with two reactive dyes, CI reactive black 5 and CI reactive red 195. The cellulose nanofibers were prepared by electrospinning of cellulose acetate (CA) followed by deacetylation. The FTIR results confirmed complete conversion of CA into cellulose nanofibers. Dyeing parameters optimized were dyeing temperature, dyeing time and dye concentrations for each class of the dye used. Results revealed that the ultrasonic dyeing produced higher color yield (K/S values) than the conventional dyeing. The color fastness test results depicted good dye fixation. SEM analysis evidenced that ultrasonic energy during dyeing do not affect surface morphology of nanofibers. The results conclude successful dyeing of cellulose nanofibers using ultrasonic energy with better color yield and color fastness results than conventional dyeing. PMID:26964959

  17. Indications and postoperative treatment for Ex-PRESS® insertion in Japanese patients with glaucoma: comparison with standard trabeculectomy

    Directory of Open Access Journals (Sweden)

    Kato N

    2015-08-01

    Full Text Available Noriko Kato,1,2 Genichiro Takahashi,1,2 Koichi Kumegawa,1,2 Yoshiaki Kabata,1,2 Hiroshi Tsuneoka1 1Department of Ophthalmology, Jikei University, School of Medicine, 2Katsushika Medical Center, Tokyo, Japan Background: We investigated indications and early postoperative treatment for Ex-PRESS® insertion for glaucoma by comparing postoperative outcomes with those for standard trabeculectomy. Methods: Ex-PRESS insertion was performed in 21 eyes and standard trabeculectomy (TLE in 22 eyes. Mean intraocular pressure (IOP in the 6 months after surgery, success rate for postoperative IOP decline, postoperative complications, postoperative treatment, filtering blebs, and indications were then retrospectively investigated. Results: Mean postoperative IOP did not differ significantly between the groups at any observation time for 6 months after surgery. Further, it did not differ between either the groups of patients with primary open-angle glaucoma (POAG and neovascular glaucoma (NTG, or the patients with primary open-angle glaucoma and NTG in the Ex-PRESS group. Comparison of success rates in reduction of postoperative IOP between the groups under the following four survival conditions showed no significant differences: postoperative IOP <30% of the preoperative IOP, complete success (no additional ophthalmic solution, and qualified success (ophthalmic solution required; 5 mmHg ≤ postoperative IOP ≤21 mmHg, complete success (no additional ophthalmic solution, and qualified success (ophthalmic solution required. With regard to postoperative complications and postoperative treatment, the incidence of hyphema was significantly lower in the Ex-PRESS group, but no other significant intergroup differences were seen. The height of the filtering bleb was lower in the Ex-PRESS group. Conclusion: Postoperative outcomes in the Ex-PRESS and TLE groups were comparable. The incidence of hyphema was significantly lower in the Ex-PRESS group. Ex-PRESS insertion

  18. Adaptive mutation related to cellulose producibility in Komagataeibacter medellinensis (Gluconacetobacter xylinus) NBRC 3288.

    Science.gov (United States)

    Matsutani, Minenosuke; Ito, Kohei; Azuma, Yoshinao; Ogino, Hidetaka; Shirai, Mutsunori; Yakushi, Toshiharu; Matsushita, Kazunobu

    2015-09-01

    Gluconacetobacter xylinus (formerly Acetobacter xylinum and presently Komagataeibacter medellinensis) is known to produce cellulose as a stable pellicle. However, it is also well known to lose this ability very easily. We investigated the on and off mechanisms of cellulose producibility in two independent cellulose-producing strains, R1 and R2. Both these strains were isolated through a repetitive static culture of a non-cellulose-producing K. medellinensis NBRC 3288 parental strain. Two cellulose synthase operons, types I and II, of this strain are truncated by the frameshift mutation in the bcsBI gene and transposon insertion in the bcsCII gene, respectively. The draft genome sequencing of R1 and R2 strains revealed that in both strains the bcsBI gene was restored by deletion of a nucleotide in its C-rich region. This result suggests that the mutations in the bcsBI gene are responsible for the on and off mechanism of cellulose producibility. When we looked at the genomic DNA sequences of other Komagataeibacter species, several non-cellulose-producing strains were found to contain similar defects in the type I and/or type II cellulose synthase operons. Furthermore, the phylogenetic relationship among cellulose synthase genes conserved in other bacterial species was analyzed. We observed that the cellulose genes in the Komagataeibacter shared sequence similarities with the γ-proteobacterial species but not with the α-proteobacteria and that the type I and type II operons could be diverged from a same ancestor in Komagataeibacter. PMID:25913006

  19. 21 CFR 524.154 - Bacitracin or bacitracin zinc-neomycin sulfate-polymyxin B sulfate ophthalmic ointment.

    Science.gov (United States)

    2010-04-01

    ...-polymyxin B sulfate ophthalmic ointment. 524.154 Section 524.154 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS OPHTHALMIC AND... sulfate ophthalmic ointment. (a) Sponsor. To firms identified in § 510.600(c) of this chapter as...

  20. 78 FR 77688 - Ophthalmic Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting

    Science.gov (United States)

    2013-12-24

    ... HUMAN SERVICES Food and Drug Administration Ophthalmic Devices Panel of the Medical Devices Advisory...). The meeting will be open to the public. Name of Committee: Ophthalmic Devices Panel of the Medical Devices Advisory Committee. General Function of the Committee: To provide advice and recommendations...

  1. 78 FR 13350 - Ophthalmic Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting

    Science.gov (United States)

    2013-02-27

    ... HUMAN SERVICES Food and Drug Administration Ophthalmic Devices Panel of the Medical Devices Advisory...). The meeting will be open to the public. Name of Committee: Ophthalmic Devices Panel of the Medical Devices Advisory Committee. General Function of the Committee: To provide advice and recommendations...

  2. 75 FR 35495 - Ophthalmic Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting

    Science.gov (United States)

    2010-06-22

    ... HUMAN SERVICES Food and Drug Administration Ophthalmic Devices Panel of the Medical Devices Advisory...). The meeting will be open to the public. Name of Committee: Ophthalmic Devices Panel of the Medical Devices Advisory Committee. General Function of the Committee: To provide advice and recommendations...

  3. 77 FR 42503 - Ophthalmic Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting

    Science.gov (United States)

    2012-07-19

    ... HUMAN SERVICES Food and Drug Administration Ophthalmic Devices Panel of the Medical Devices Advisory...). The meeting will be open to the public. Name of Committee: Ophthalmic Devices Panel of the Medical Devices Advisory Committee. General Function of the Committee: To provide advice and recommendations...

  4. 21 CFR 524.1662 - Oxytetracycline hydrochloride ophthalmic and topical dosage forms.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Oxytetracycline hydrochloride ophthalmic and topical dosage forms. 524.1662 Section 524.1662 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... DOSAGE FORM NEW ANIMAL DRUGS § 524.1662 Oxytetracycline hydrochloride ophthalmic and topical dosage forms....

  5. 21 CFR 524.1883 - Prednisolone sodium phosphate-neomycin sulfate ophthalmic ointment.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Prednisolone sodium phosphate-neomycin sulfate... DOSAGE FORM NEW ANIMAL DRUGS § 524.1883 Prednisolone sodium phosphate-neomycin sulfate ophthalmic ointment. (a) Specifications. Prednisolone sodium phosphate-neomycin sulfate ophthalmic ointment...

  6. 10 CFR 35.2433 - Records of decay of strontium-90 sources for ophthalmic treatments.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Records of decay of strontium-90 sources for ophthalmic treatments. 35.2433 Section 35.2433 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Records § 35.2433 Records of decay of strontium-90 sources for ophthalmic treatments. (a) A licensee...

  7. 76 FR 72619 - Ophthalmic and Topical Dosage Form New Animal Drugs; Eprinomectin

    Science.gov (United States)

    2011-11-25

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration 21 CFR Part 524 Ophthalmic and Topical Dosage Form New...--OPHTHALMIC AND TOPICAL DOSAGE FORM NEW ANIMAL DRUGS 0 1. The authority citation for 21 CFR part 524...

  8. 75 FR 26647 - Ophthalmic and Topical Dosage Form New Animal Drugs; Ivermectin Topical Solution

    Science.gov (United States)

    2010-05-12

    ... parasites that were approved for the pioneer product with 3 years of marketing exclusivity (69 FR 501... HUMAN SERVICES Food and Drug Administration 21 CFR Part 524 Ophthalmic and Topical Dosage Form New... part 524 is amended as follows: PART 524--OPHTHALMIC AND TOPICAL DOSAGE FORM NEW ANIMAL DRUGS 0 1....

  9. Observation on 108 Normal Ophthalmic Arteries in 80 Patients by Digital Subtraction Angiography

    Institute of Scientific and Technical Information of China (English)

    1994-01-01

    By digital subtraction angiography(DSA), the authors made observations on 108 normal ophthalmic arteries in 80 patients with regard to the origins, courses, branching, morphology and anastomoses of the vessels. The merits and demerits of DSA in observing the ophthalmic artery were discussed. Eye Science 1994; 10: 157- 162.

  10. 75 FR 4692 - Ophthalmic and Topical Dosage Form New Animal Drugs; Miconazole, Polymixin B, and Prednisolone...

    Science.gov (United States)

    2010-01-29

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration 21 CFR Part 524 Ophthalmic and Topical Dosage Form New... Veterinary Medicine, 21 CFR part 524 is amended as follows: PART 524--OPHTHALMIC AND TOPICAL DOSAGE FORM...

  11. 76 FR 81806 - Ophthalmic and Topical Dosage Form New Animal Drugs; Ivermectin Topical Solution

    Science.gov (United States)

    2011-12-29

    ... exclusivity (69 FR 501, January 6, 2004). The supplemental ANADA is approved as of September 21, 2011, and 21... HUMAN SERVICES Food and Drug Administration 21 CFR Part 524 Ophthalmic and Topical Dosage Form New... for Veterinary Medicine, 21 CFR part 524 is amended as follows: PART 524--OPHTHALMIC AND...

  12. 75 FR 16346 - Ophthalmic and Topical Dosage Form New Animal Drugs; Orbifloxacin, Mometasone Furoate Monohydrate...

    Science.gov (United States)

    2010-04-01

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration 21 CFR Part 524 Ophthalmic and Topical Dosage Form New... Veterinary Medicine, 21 CFR part 524 is amended as follows: PART 524--OPHTHALMIC AND TOPICAL DOSAGE FORM...

  13. 78 FR 46977 - Ophthalmic Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting

    Science.gov (United States)

    2013-08-02

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration Ophthalmic Devices Panel of the Medical Devices Advisory...). The meeting will be open to the public. Name of Committee: Ophthalmic Devices Panel of the...

  14. Cellulose Derivatives for Water Repellent Properties

    Science.gov (United States)

    In this poster presentation, we will discuss the synthesis and structural characterizations of nitro-benzyl cellulose (1), amino-benzyl cellulose (2) and pentafluoro –benzyl cellulose (3). All cellulose derivatives are synthesized by etherification process in lithium chloride/N,N-dimethylacetamide h...

  15. Cellulose nanocrystals: synthesis, functional properties, and applications

    OpenAIRE

    George J.; Sabapathi SN

    2015-01-01

    Johnsy George, SN Sabapathi Food Engineering and Packaging Division, Defence Food Research Laboratory, Siddarthanagar, Mysore, Karnataka, India Abstract: Cellulose nanocrystals are unique nanomaterials derived from the most abundant and almost inexhaustible natural polymer, cellulose. These nanomaterials have received significant interest due to their mechanical, optical, chemical, and rheological properties. Cellulose nanocrystals primarily obtained from naturally occurring cellulose fibers...

  16. Cellulose synthase complexes: structure and regulation

    Directory of Open Access Journals (Sweden)

    Lei eLei

    2012-04-01

    Full Text Available This review is to update the most recent progress on characterization of the composition, regulation, and trafficking of cellulose synthase complexes. We will highlight proteins that interact with cellulose synthases, e.g. cellulose synthase-interactive protein 1 (CSI1. The potential regulation mechanisms by which cellulose synthase interact with cortical microtubules in primary cell walls will be discussed.

  17. Pharmaceutical significance of cellulose: A review

    Directory of Open Access Journals (Sweden)

    2008-11-01

    Full Text Available The amalgamation of polymer and pharmaceutical sciences led to the introduction of polymer in the design and development of drug delivery systems. Polymeric delivery systems are mainly intended to achieve controlled or sustained drug delivery. Polysaccharides fabricated into hydrophilic matrices remain popular biomaterials for controlled-release dosage forms and the most abundant naturally occurring biopolymer is cellulose; so hdroxypropylmethyl cellulose, hydroxypropyl cellulose, microcrystalline cellulose and hydroxyethyl cellulose can be used for production of time controlled delivery systems. Additionally microcrystalline cellulose, sodium carboxymethyl cellulose, hydroxypropylmethyl cellulose, hydroxyethyl cellulose as well as hydroxypropyl cellulose are used to coat tablets. Cellulose acetate phthalate and hydroxymethyl cellulose phthalate are also used for enteric coating of tablets. Targeting of drugs to the colon following oral administration has also been accomplished by using polysaccharides such as hdroxypropylmethyl cellulose and hydroxypropyl cellulose in hydrated form; also they act as binders that swell when hydrated by gastric media and delay absorption. This paper assembles the current knowledge on the structure and chemistry of cellulose, and in the development of innovative cellulose esters and ethers for pharmaceuticals.

  18. Radiation degradation of cellulose

    International Nuclear Information System (INIS)

    The application of straw and other cellulose polymers as feedstuff for ruminants is limited by its low digestibility. During recent decades it was attempted to increase the digestibility of straw by several chemical and physical methods. In this work some results of the degradation of gamma and electron treated wheat straw are reported. Complex methods of treatment (e.g. radiation influence and influence of lyes) are taken into consideration. In vitro-experiments with radiation treated straw show that the digestibility can be increased from 20% up to about 80%. A high pressure liquid chromatography method was used to analyze the hydrolysates. The contents of certain species of carbohydrates in the hydrolysates in dependence on the applied dose are given

  19. A Study To Evaluate Skills Of Ophthalmic Assistants For Assessment Of Cup Disc Ratio

    Directory of Open Access Journals (Sweden)

    Malik J.S

    1999-01-01

    Full Text Available Research question: 1. Whether paramedical ophthalmic assistants can be trained to examine vertical cup disc ratio? 2. Can the PMO As detect abnormal cup disc ratio after training? Objectives: 1. T o train ophthalmic assistants in cup disc ratio examination 2. To evaluate skills of trained ophthalmic assistants in cup disc ratio examination Study design: Cross sectional Setting: OPD of Ophthalmology department, Pt. B.D. Sharma PGIMS, Rohtak Participants: Five paramedical ophthalmic assistants, one ophthalmologist and 322 patients above 40 years of age. Statistical analysis: Sensitivity, specificity, Kappa values. Results: Data analysis of 322 cases was found by PMO As and ophthalmologist revealed sensitivity between 50-65% and specificity between 84.5-92.62%. A good agreement was found among all the examiners on computation of Kappa Values. It was concluded that ophthalmic assistants can examine vertical cup disc ratio after five days training.

  20. The assessment of visually impaired persons working capacities using electrophysiological and ophthalmic ergonomics methods

    Directory of Open Access Journals (Sweden)

    M. I. Razumovsky

    2014-07-01

    Full Text Available Aim was to analyze working capacities of visually impaired persons by means of complex electrophysiological and ophthalmic ergonomics eye examination.Materials and methods. Standard clinical ophthalmologic examination (visual acuity measurement, refractometry, biomicroscopy, ophthalmoscopy as well as electrophysiological (electrooculography, electrical sensitivity of the eye, critical flicker fusion frequency and ophthalmic ergonomics tests (accommodation measurement, professional testing using automated system «Proftest-1» were performed.Results. Complex electrophysiological and ophthalmic ergonomics tests were performed in 20 visually impaired persons. Their results revealed direct correlation between electrophysiological and ophthalmic ergonomics indices.Conclusion. Working capacities of visually impaired persons can be assessed reliably using complex electrophysiological and ophthalmic ergonomics eye examination only.

  1. The assessment of visually impaired persons working capacities using electrophysiological and ophthalmic ergonomics methods

    Directory of Open Access Journals (Sweden)

    M. I. Razumovsky

    2014-01-01

    Full Text Available Aim was to analyze working capacities of visually impaired persons by means of complex electrophysiological and ophthalmic ergonomics eye examination.Materials and methods. Standard clinical ophthalmologic examination (visual acuity measurement, refractometry, biomicroscopy, ophthalmoscopy as well as electrophysiological (electrooculography, electrical sensitivity of the eye, critical flicker fusion frequency and ophthalmic ergonomics tests (accommodation measurement, professional testing using automated system «Proftest-1» were performed.Results. Complex electrophysiological and ophthalmic ergonomics tests were performed in 20 visually impaired persons. Their results revealed direct correlation between electrophysiological and ophthalmic ergonomics indices.Conclusion. Working capacities of visually impaired persons can be assessed reliably using complex electrophysiological and ophthalmic ergonomics eye examination only.

  2. Resistance to fluoroquinolones and methicillin in ophthalmic isolates of Staphylococcus pseudintermedius from companion animals.

    Science.gov (United States)

    Kang, Min-Hee; Chae, Min-Joo; Yoon, Jang-Won; Lee, So-Young; Yoo, Jong-Hyun; Park, Hee-Myung

    2014-07-01

    Resistance to fluoroquinolones and methicillin was determined for 49 ophthalmic isolates of Staphylococcus pseudintermedius from dogs with and without ophthalmic disease. Resistance was observed for ciprofloxacin (40.8%), ofloxacin (38.8%), enrofloxacin (38.8%), levofloxacin (34.7%), and moxifloxacin (4.1%). Eighteen isolates, 16 of which were resistant to oxacillin, were mecA-positive. Nine of the 16 oxacillin-resistant mecA-positive S. pseudintermedius isolates were resistant to more than one fluoroquinolone and 2 isolates were resistant to 5 fluoroquinolones. The frequency of mecA gene occurrence and fluoroquinolone resistance was twice as high among S. pseudintermedius isolates derived from dogs with ophthalmic disease compared with isolates for dogs without ophthalmic disease. The high prevalence of methicillin and fluoroquinolone resistance in S. pseudintermedius from dogs with ophthalmic disease is a concern. PMID:24982521

  3. Increasing incidence of ophthalmic lymphoma in Denmark from 1980 to 2005

    DEFF Research Database (Denmark)

    Sjö, Lene D; Ralfkiær, Elisabeth Methner; Prause, Jan U;

    2008-01-01

    PURPOSE: To evaluate patient characteristics and incidence of ophthalmic lymphoma in Denmark during the period 1980 to 2005. METHODS: All patients in Denmark with a diagnosis of ophthalmic lymphoma during the period 1980 to 2005 were retrieved from three different population-based registries....... Specimens from all patients were collected and reclassified according to the World Health Organization (WHO) classification system. Incidence rates were calculated by using Poisson regression models. RESULTS: A total of 228 patients with a histologically verified diagnosis of ophthalmic lymphoma were...... Danish population ophthalmic lymphoma consists primarily of orbital MALT lymphoma. Although it is a rare disease in mostly elderly patients, the incidence of ophthalmic lymphoma is increasing at a rapid pace....

  4. IMPORTANCE OF MEDICAL AUDIT IN A COMMUNITY OPHTHALMIC OUTREACH PROGRAM

    Directory of Open Access Journals (Sweden)

    Shubhangi Prashant

    2014-05-01

    Full Text Available Outreach delivery of health care is an important part of Community ophthalmology, especially for Cataract patients. Quality assurance in such programmes, which guarantees every patient of best possible outcomes and fewest possible complications in such programmes of key importance. OBJECTIVES: To study the importance of medical audit in assessing & assuring the quality of surgical services provided to the patients in community ophthalmic outreach programmes. STUDY DESIGN: Cross Sectional Study. SETTING: Tertiary Level Eye Hospital and Locations of Outreach Camps. DURATION OF STUDY: 1 year, April 2010 to March 2011. METHODS & MATERIAL: Patients who had no ocular problems other than cataract & had undergone Cataract surgery as part of Outreach programmes, in 2 months – 1 year postoperative period, were selected at random. Interviewed & examined with Snellen's chart, Hand held Slit Lamp & Direct Ophthalmoscope to assess results of cataract surgery including complications. The data thus obtained was statistically analyzed for assessing the quality & effectiveness of community ophthalmic outreach programmes. RESULTS: Of the 1014 patients surveyed 59% were females. 31.5 % Patients got both eyes operated. Thus total 1334 eyes surveyed. 88% of surgeries in the given year have resulted in Good Vision as per WHO Standards. 11% & 2% surgeries resulted in intermediate and poor vision respectively. Only 2% of patients had to be brought to the hospital for further management. Most commonly encountered undesired effect was watering, noted in 2.7% patients followed by itching, redness, mostly in the early postoperative period. Most patients were satisfied about the services they obtained. CONCLUSION: Medical Audit is the mainstay in assessing & assuring the quality of community ophthalmic outreach programmes, which in turn maintain a public trust in the programme. It also helps in building a long term patient contact & finding out areas and groups where

  5. Simultaneous Bilateral Ophthalmic Artery Chemosurgery for Bilateral Retinoblastoma (Tandem Therapy)

    Science.gov (United States)

    Abramson, David H.; Marr, Brian P.; Francis, Jasmine H.; Dunkel, Ira J.; Fabius, Armida W. M.; Brodie, Scott E.; Mondesire-Crump, Ijah; Gobin, Y. Pierre

    2016-01-01

    Objective Report on the 7-year experience with bilateral ophthalmic artery chemosurgery (OAC-Tandem therapy) for bilateral retinoblastoma. Design Retrospective, single institution study. Subjects 120 eyes of 60 children with bilateral retinoblastoma treated since March 2008. Methods Retrospective review of all children treated at Memorial Sloan Kettering with bilateral ophthalmic artery chemosurgery (Melphalan, Carboplatin, Topotecan, Methotrexate) delivered in the same initial session to both naïve and previously treated eyes. Main Outcome Measures Ocular survival, metastatic disease, patient survival from metastases, second cancers, systemic adverse effects, need for transfusion of blood products, electroretinogram before and after treatment. Results 116 eyes were salvaged (4 eyes were enucleated: 3 because of progressive disease, 1 family choice). Kaplan Meier ocular survival was 99.2% at one year, 96.9% at 2 and 3 years and 94.9% for years 4 through 7. There were no cases of metastatic disease or metastatic deaths with a mean follow-up of 3.01 years. Two children developed second cancers (both pineoblastoma) and one of them died. Transfusion of blood products was required in 3 cases (4 transfusions), 1.9%. Two children developed fever/neutropenia requiring hospitalization (0.95%). ERGs were improved in 21.6% and unchanged after treatment in 52.5% of cases (increase or decrease of less than 25μV). Conclusions Bilateral ophthalmic artery chemosurgery is a safe and effective technique for managing bilateral retinoblastoma-even when eyes are advanced bilaterally, and if both eyes have progressed after systemic chemotherapy. Ocular survival was excellent (94.9% at 8 years), there were no cases of of metastatic disease and no deaths from metastatic disease, but children remain at risk for second cancers. In 21.6% of cases ERG function improved. Despite using chemotherapy in both eyes in the same session, systemic toxicity was low. PMID:27258771

  6. Ophthalmic disorders in adult lymphoma patients in Africa

    Directory of Open Access Journals (Sweden)

    Omoti Afekhide

    2009-01-01

    Full Text Available Context: Ocular manifestations of lymphoma are rare events. Most reports of ocular involvement in lymphoma are case reports or reports of a few patients. Aims: To determine the ophthalmic disorders in adult, African, lymphoma patients. Settings and Design: A prospective study of ocular disorders in adult patients with lymphoma was conducted at the University of Benin Teaching Hospital, Benin City, Nigeria, between July 2004 and June 2007. Materials and Methods: The patients were interviewed and examined by the authors and the ocular findings recorded. Statistical Analysis: Data was analyzed on computer with the aid of the Instat GraghPad™ v2.05a statistical package software. The mean, standard deviation, Mann-Whitney U-statistic and P value were calculated. Results: A total of 111 patients with hematological malignancies were seen over a period of three years of which 62 (55.85% had lymphomas. Of these, 51(82.3% were non-Hodgkin′s lymphoma and 11(17.7% were Hodgkin′s lymphoma. Ocular disorders occurred in 16 patients (31.4% with non-Hodgkin′s lymphoma and none of the patients with Hodgkin′s lymphoma (Mann-Whitney U-statistic is equal to 7.500, U′ is equal to161.50, P , 0.0001. The ocular disorders due to non-Hodgkin′s lymphoma were seen as - proptosis in six patients (11.8%, retinopathies in three (5.9%, conjunctival infiltration in three (5.9%, optic atrophy in two (3.9%, keratoconjunctivitis in one (two per cent, desquamating nodular lid lesions in one (two per cent, papilloedema in one (two per cent, and upper lid mass in one (two per cent. Four patients (6.5% had monocular blindness. Conclusions: Ophthalmic disorders are relatively common in non-Hodgkin′s lymphoma. Ophthalmic evaluation is needed in these patients for early identification and treatment of potentially blinding conditions.

  7. Dose uniformity of topical corticosteroid preparations: difluprednate ophthalmic emulsion 0.05% versus branded and generic prednisolone acetate ophthalmic suspension 1%

    OpenAIRE

    William Stringer; Roy Bryant

    2010-01-01

    William Stringer1, Roy Bryant21Module 3 Pharma Services, St. Petersburg, Florida; 2Encompass Pharmaceutical Services, Norcross, Georgia, USAPurpose: To compare the dose uniformity of difluprednate ophthalmic emulsion 0.05% (Durezol®) with both branded and generic prednisolone acetate ophthalmic suspension 1% under different simulated patient usage conditions.Methods: Drug concentrations of difluprednate emulsion, branded prednisolone acetate suspension (Pred Forte®) and generi...

  8. Insertion compounds of uranium oxides

    International Nuclear Information System (INIS)

    Insertion compounds are formed by the intercalation of an electropositive species, such as hydrogen or an alkali metal, with minimal structural rearrangement of the host oxide. In this report a review of the measured structural, thermodynamic and transport properties of the insertion compounds of α-U3O8, α-UO3, γ-UO3, δ-UO3 and related systems is given. (author)

  9. Thermophilic degradation of cellulosic biomass

    Science.gov (United States)

    Ng, T.; Zeikus, J. G.

    1982-12-01

    The conversion of cellulosic biomass to chemical feedstocks and fuel by microbial fermentation is an important objective of developing biotechnology. Direct fermentation of cellulosic derivatives to ethanol by thermophilic bacteria offers a promising approach to this goal. Fermentations at elevated temperatures lowers the energy demand for cooling and also facilitates the recovery of volatile products. In addition, thermophilic microorganisms possess enzymes with greater stability than those from mesophilic microorganisms. Three anaerobic thermophilic cocultures that ferment cellulosic substrate mainly to ethanol have been described: Clostridium thermocellum/Clostriidium thermohydrosulfuricum, C. thermocellum/Clostridium thermosaccharolyticum, and C. thermocellum/Thermoanaerobacter ethanolicus sp. nov. The growth characteristics and metabolic features of these cocultures are reviewed.

  10. Supercritical solvent impregnation of ophthalmic drugs on chitosan derivatives

    OpenAIRE

    Braga, Mara E. M.; Pato, Maria T. Vaz; Silva, Hélio S. R. Costa; Ferreira, Elisabeth I.; Gil, Maria H.; Duarte, Catarina M. M.; Sousa, Hermínio C. de

    2008-01-01

    In this work, three chitosan derivatives (N-carboxymethyl chitosan (CMC), N-carboxybutyl chitosan (CBC) and N-succinyl chitosan (SCC)) were impregnated with flurbiprofen (an anti-inflammatory drug) and timolol maleate (an anti-glaucoma drug), using a supercritical solvent impregnation (SSI) technique (and employing high pressure CO2 and CO2 + EtOH mixtures) in order to develop hydrogel-type ophthalmic drug delivery applications. Impregnation experiments were carried out from 9.0 up to 14.0 MP...

  11. Ophthalmic Manifestations of Linear Nevus Sebaceous/Organoid Nevus Syndrome

    International Nuclear Information System (INIS)

    Linear Nevus Sebaceous Syndrome (LNSS) is a rare sporadic oculoneurocutaneous disorder, also classified as Organoid Nevus Syndrome. It consists of a triad of midline facial linear nevus sebaceous, central nervous system and ocular abnormalities. To the best of authors' knowledge ophthalmic features of LNSS have never been reported in Pakistani population. We report two cases of LNSS, associated with multiple cutaneous nevus sebaceous lesions, complex ocular choristomas and rare bilateral presentation in one patient. Ocular choristomas included limbal dermoids, dermolipomas at superior fornices and chroidal choristoma. Ocular surface was successfully reconstructed by excision of limbal dermoids, partial keratectomy and amniotic membrane transp. (author)

  12. Characterization of Cellulose Synthesis in Plant Cells

    OpenAIRE

    Samaneh Sadat Maleki; Kourosh Mohammadi; Kong-shu Ji

    2016-01-01

    Cellulose is the most significant structural component of plant cell wall. Cellulose, polysaccharide containing repeated unbranched β (1-4) D-glucose units, is synthesized at the plasma membrane by the cellulose synthase complex (CSC) from bacteria to plants. The CSC is involved in biosynthesis of cellulose microfibrils containing 18 cellulose synthase (CesA) proteins. Macrofibrils can be formed with side by side arrangement of microfibrils. In addition, beside CesA, various proteins like the...

  13. Access to the ophthalmic artery by retrograde approach through the posterior communicating artery for intra-arterial chemotherapy of retinoblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Pham, Chi-Tuan; Blanc, Raphael; Pistocchi, Silvia; Bartolini, Bruno; Piotin, Michel [Fondation Rothschild Hospital, Department of Interventional Neuroradiology, Paris (France); Lumbroso-Le Rouic, Livia [Institut Curie, Department of Ocular Oncology, Paris (France)

    2012-08-15

    Intra-arterial infusion of chemotherapy into the ophthalmic artery for treatment of retinoblastoma has been realized after catheterization of the internal carotid and temporary balloon occlusion beyond the orifice of the ophthalmic artery, or more recently after superselective canulation of the ophthalmic artery by a microcatheter. The superselective catheterization of the ophthalmic artery could be cumbersome because of the implantation of the ostium on the carotid siphon or because of the tortuosity of the carotid siphon. We report our experience of using a retrograde approach through the posterior communicating artery that allows a more direct angle of access to the origin of the ophthalmic artery. (orig.)

  14. Access to the ophthalmic artery by retrograde approach through the posterior communicating artery for intra-arterial chemotherapy of retinoblastoma

    International Nuclear Information System (INIS)

    Intra-arterial infusion of chemotherapy into the ophthalmic artery for treatment of retinoblastoma has been realized after catheterization of the internal carotid and temporary balloon occlusion beyond the orifice of the ophthalmic artery, or more recently after superselective canulation of the ophthalmic artery by a microcatheter. The superselective catheterization of the ophthalmic artery could be cumbersome because of the implantation of the ostium on the carotid siphon or because of the tortuosity of the carotid siphon. We report our experience of using a retrograde approach through the posterior communicating artery that allows a more direct angle of access to the origin of the ophthalmic artery. (orig.)

  15. Chromophores in lignin-free cellulosic materials belong to three compound classes. Chromophores in cellulosics, XII

    Science.gov (United States)

    The CRI (chromophore release and identification) method isolates well-defined chromophoric substances from different cellulosic matrices, such as highly bleached pulps, cotton linters, bacterial cellulose, viscose or lyocell fibers, and cellulose acetates. The chromophores are present only in extrem...

  16. Bacterial cellulose/boehmite composites

    Energy Technology Data Exchange (ETDEWEB)

    Salvi, Denise T.B. de; Barud, Hernane S.; Messaddeq, Younes; Ribeiro, Sidney J.L. [Universidade Estadual Paulista Julio de Mesquita Filho. UNESP. Instituto de Quimica de Araraquara, SP (Brazil); Caiut, Jose Mauricio A. [Universidade de Sao Paulo. Departamento de Quimica - FFCLRP/USP, Ribeirao Preto, SP (Brazil)

    2011-07-01

    Composites based on bacterial cellulose membranes and boehmite were obtained. SEM results indicate that the bacterial cellulose (BC) membranes are totally covered by boehmite and obtained XRD patterns suggest structural changes due to this boehmite addition. Thermal stability is accessed through TG curves and is dependent on boehmite content. Transparency is high comparing to pure BC as can be seen through UV-vis absorption spectroscopy. (author)

  17. Bacterial cellulose/boehmite composites

    International Nuclear Information System (INIS)

    Composites based on bacterial cellulose membranes and boehmite were obtained. SEM results indicate that the bacterial cellulose (BC) membranes are totally covered by boehmite and obtained XRD patterns suggest structural changes due to this boehmite addition. Thermal stability is accessed through TG curves and is dependent on boehmite content. Transparency is high comparing to pure BC as can be seen through UV-vis absorption spectroscopy. (author)

  18. The fate of free radicals in a cellulose based hydrogel: detection by electron paramagnetic resonance spectroscopy.

    Science.gov (United States)

    Basumallick, Lipika; Ji, J Andrea; Naber, Nariman; Wang, Y John

    2009-07-01

    Cellulose derivatives are commonly used as gelling agents in topical and ophthalmic drug formulations. During the course of manufacturing, cellulose derivatives are believed to generate free radicals. These free radicals may degrade the gelling agent, leading to lower viscosity. Free radicals also may react with the active ingredient in the product. The formation of radicals in a 3% hydrogel of hypromellose (hydroxypropyl methylcellulose) was monitored by electron paramagnetic resonance (EPR) spectroscopy and spin trapping techniques. Radicals were trapped with 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) and quantitated by comparing the EPR intensity with 4-hydroxy-2,2,6,6-tetramethylpiperidinyloxy (TEMPOL), a stable free radical. Typically, the hydrogels showed an initial increase in the radical concentration within 2 days after autoclaving, followed by a drop in radical concentration in 7 days. EDTA prevented the formation of free radicals in the hypromellose (HPMC) hydrogel, suggesting the involvement of metal ions in the generation of free radicals. The oxidizing potential of the hydrogel was estimated by measuring the rate at which methionine (a model for the protein active pharmaceutical ingredient) was degraded, and was consistent with the amount of radicals present in the gel. This study is the first report investigating the application of EPR spectroscopy in detecting and estimating free radical concentration in cellulose based hydrogels. PMID:19090570

  19. Formulation evaluation and validation of ophthalmic emulsion of docosahexaenoic acid

    Directory of Open Access Journals (Sweden)

    R. R. Nikhade

    2014-03-01

    Full Text Available The present study aimed at the formulation evaluation and validation of ophthalmic emulsion of docosahexaenoic acid for ophthalmic delivery of drug. Preparation of oil-in-water (o/w type emulsion is one of the approaches to formulate drugs that are poorly water-soluble. When DHA is administered in  capsule dosage form then less amount of drug reaches to the site of inflammation in the eye hence more dose is required, still the inflammation is at risk. Hence, for the direct application of DHA to the eye it can be prepared in the form of eye drops. As the fish oil is richest source of DHA it was isolated from it. The isolated compound was identified by thin layer chromatography by comparing it with standard DHA. Further analysis of isolated compound was done by gas chromatography. The oil in water emulsion was formulated containing 3% DHA oil, 1% tween 80 and 0.5% span 80. The appearance of the emulsion was milky white, the median particle size was 0.4 µm, viscosity was 30 cp, The emulsion was stable at 25ºC and 40ºC for more than 3 months. furthermore the formulated emulsion was validated for the same physical properties which are previously evaluated. The analysis of DHA in the emulsion was done by gas chromatography.

  20. Microgravity-Induced Fluid Shift and Ophthalmic Changes

    Directory of Open Access Journals (Sweden)

    Emily S. Nelson

    2014-11-01

    Full Text Available Although changes to visual acuity in spaceflight have been observed in some astronauts since the early days of the space program, the impact to the crew was considered minor. Since that time, missions to the International Space Station have extended the typical duration of time spent in microgravity from a few days or weeks to many months. This has been accompanied by the emergence of a variety of ophthalmic pathologies in a significant proportion of long-duration crewmembers, including globe flattening, choroidal folding, optic disc edema, and optic nerve kinking, among others. The clinical findings of affected astronauts are reminiscent of terrestrial pathologies such as idiopathic intracranial hypertension that are characterized by high intracranial pressure. As a result, NASA has placed an emphasis on determining the relevant factors and their interactions that are responsible for detrimental ophthalmic response to space. This article will describe the Visual Impairment and Intracranial Pressure syndrome, link it to key factors in physiological adaptation to the microgravity environment, particularly a cephalad shifting of bodily fluids, and discuss the implications for ocular biomechanics and physiological function in long-duration spaceflight.

  1. Ophthalmic manifestations of methylmalonic aciduria accompanied with homocystinuria

    Directory of Open Access Journals (Sweden)

    Qiu-Jing Huang

    2015-12-01

    Full Text Available Methylmalonicaciduia(MMAaccompanied with homocystinuria is a rare autosomal-recessive with congenital metabolic disorder of Vitamin B12. There are three subtypes, cblC, cblD, cblF, in which cblC is the most common one. The diagnostic tests are tandem mass spectrometry and gas chromatography-mass spectrometry. Tests for activity of enzyme in fibroblasts from skin, complementary assay and genetic analysis can be used to make the subtype clear. Early-onset patients, defined by onset of symptoms before the age of 1 year, may have severe ocular involvement, including visual loss, nystagmus, strabismus, retinopathy, maculopathy, optic atrophy, abnormal electroretinography. Late-onset patients, defined by onset of symptoms after the age of 4 year, rarely have ocular manifestations. The pathogenesis of the ophthalmic symptoms may be related to the high level of homocystine, oxidative stress and the abnormal development of nervous systems. The treatment for MMA accompanied with homocystinuria is mostly symptomatic based. Ophthalmic treatment is limited. Early supplement of methionine,GSH or other antioxidants may be helpful for retinopathy. There is no standard ophthalmological examination for those patients in China. It is critical to set up inter-departmental cooperation and early stage examination for the treatments and outcomes of the patients.

  2. Clinical utility of voriconazole eye drops in ophthalmic fungal keratitis

    Directory of Open Access Journals (Sweden)

    Daoud Al-Badriyeh

    2010-05-01

    Full Text Available Daoud Al-Badriyeh, Chin Fen Neoh, Kay Stewart, David CM KongCentre for Medicine Use and Safety, Faculty of Pharmacy and Pharmaceutical Sciences, Monash University, Victoria, AustraliaAbstract: Fungal keratitis is one of the major causes of ophthalmic mycosis and is difficult to treat. The range of common antifungal agents available for fungal keratitis remains inadequate and is generally associated with poor clinical outcomes. Voriconazole is a new generation triazole antifungal agent. Only marketed in systemic formulation and, with broad-spectrum activity and high intraocular penetration, voriconazole has demonstrated effectiveness against fungal keratitis. Systemic voriconazole, however, is not without side effects and is costly. Voriconazole eye drops have been prepared extemporaneously and used for the treatment of ophthalmic fungal keratitis. The current article sought to review the literature for evidence related to the effectiveness and safety of topical voriconazole and its corneal penetration into the aqueous humor of the eye. The voriconazole eye drops used are typically of 1% concentration, well tolerated by the eye, and are stable. Despite existing evidence to suggest that the eye drops are effective in the treatment of fungal keratitis, more studies are needed, especially in relation to using the eye drops as first-line and stand-alone treatment, preparation of higher concentrations, and optimal dosing frequency.Keywords: voriconazole, fungal keratitis, eye drops, corneal penetration

  3. Clinical utility of voriconazole eye drops in ophthalmic fungal keratitis.

    Science.gov (United States)

    Al-Badriyeh, Daoud; Neoh, Chin Fen; Stewart, Kay; Kong, David C M

    2010-01-01

    Fungal keratitis is one of the major causes of ophthalmic mycosis and is difficult to treat. The range of common antifungal agents available for fungal keratitis remains inadequate and is generally associated with poor clinical outcomes. Voriconazole is a new generation triazole antifungal agent. Only marketed in systemic formulation and, with broad-spectrum activity and high intraocular penetration, voriconazole has demonstrated effectiveness against fungal keratitis. Systemic voriconazole, however, is not without side effects and is costly. Voriconazole eye drops have been prepared extemporaneously and used for the treatment of ophthalmic fungal keratitis. The current article sought to review the literature for evidence related to the effectiveness and safety of topical voriconazole and its corneal penetration into the aqueous humor of the eye. The voriconazole eye drops used are typically of 1% concentration, well tolerated by the eye, and are stable. Despite existing evidence to suggest that the eye drops are effective in the treatment of fungal keratitis, more studies are needed, especially in relation to using the eye drops as first-line and stand-alone treatment, preparation of higher concentrations, and optimal dosing frequency. PMID:20463910

  4. Association between Ophthalmic Timolol and Hospitalisation for Bradycardia

    Directory of Open Access Journals (Sweden)

    Nicole L. Pratt

    2015-01-01

    Full Text Available Introduction. Ophthalmic timolol, a topical nonselective beta-blocker, has the potential to be absorbed systemically which may cause adverse cardiovascular effects. This study was conducted to determine whether initiation of ophthalmic timolol was associated with an increased risk of hospitalisation for bradycardia. Materials and Methods. A self-controlled case-series study was undertaken in patients who were hospitalised for bradycardia and were exposed to timolol. Person-time after timolol initiation was partitioned into risk periods: 1–30 days, 31–180 days, and >180 days. A 30-day risk period prior to initiating timolol was also included. All remaining time was considered unexposed. Results. There were 6,373 patients with at least one hospitalisation for bradycardia during the study period; 267 were exposed to timolol. Risk of bradycardia was significantly increased in the 31–180 days after timolol initiation (incidence rate ratio (IRR = 1.93; 95% confidence interval (CI 1.00–1.87. No increased risk was observed in the first 30 days or beyond 180 days of continuous exposure (IRR = 1.40; 95% CI 0.87–2.26 and IRR = 1.21; 95% CI 0.64–2.31, resp.. Conclusion. Bradycardia is a potential adverse event following timolol initiation. Practitioners should consider patient history before choosing a glaucoma regime and closely monitor patients after treatment initiation with topical nonselective beta-blocker eye drops.

  5. Cellulose biosynthesis in Acetobacter xylinum

    International Nuclear Information System (INIS)

    Time-lapse video microscopy has shown periodic reversals during the synthesis of cellulose. In the presence of Congo Red, Acetobacter produces a band of fine fibrils. The direction of cell movement is perpendicular to the longitudinal axis of cell, and the rate of movement was decreased. A linear row of particles, presumably the cellulose synthesizing complexes, was found on the outer membrane by freeze-fracture technique. During the cell cycle, the increase of particles in linear row, the differentiation to four linear rows and the separation of the linear rows have been observed. A digitonin-solubilized cellulose synthase was prepared from A. xylinum, and incubated under conditions known to lead to active in vitro synthesis of 1,4-β-D-glucan polymer. Electron microscopy revealed that clusters of fibrils were assembled within minutes. Individual fibrils are 17 ± 2 angstroms in diameter. Evidence for the cellulosic composition of newly synthesized fibrils was based on incorporation of tritium from UDP-[3H] glucose binding of gold-labeled cellobiohydrolase, and an electron diffraction pattern identified as cellulose II polymorph instead of cellulose I

  6. Gene Insertion Patterns and Sites

    Science.gov (United States)

    Vain, Philippe; Thole, Vera

    During the past 25 years, the molecular analysis of transgene insertion patterns and sites in plants has greatly contributed to our understanding of the mechanisms underlying transgene integration, expression, and stability in the nuclear genome. Molecular characterization is also an essential step in the safety assessment of genetically modified crops. This chapter describes the standard experimental procedures used to analyze transgene insertion patterns and loci in cereals and grasses transformed using Agrobacterium tumefaciens or direct transfer of DNA. Methods and protocols enabling the determination of the number and configuration of transgenic loci via a combination of inheritance studies, polymerase chain reaction, and Southern analyses are presented. The complete characterization of transgenic inserts in plants is, however, a holistic process relying on a wide variety of experimental approaches. In this chapter, these additional approaches are not detailed but references to relevant bibliographic records are provided.

  7. Opportunity for profitable investments in cellulosic biofuels

    International Nuclear Information System (INIS)

    Research efforts to allow large-scale conversion of cellulose into biofuels are being undertaken in the US and EU. These efforts are designed to increase logistic and conversion efficiencies, enhancing the economic competitiveness of cellulosic biofuels. However, not enough attention has been paid to the future market conditions for cellulosic biofuels, which will determine whether the necessary private investment will be available to allow a cellulosic biofuels industry to emerge. We examine the future market for cellulosic biofuels, differentiating between cellulosic ethanol and 'drop-in' cellulosic biofuels that can be transported with petroleum fuels and have equivalent energy values. We show that emergence of a cellulosic ethanol industry is unlikely without costly government subsidies, in part because of strong competition from conventional ethanol and limits on ethanol blending. If production costs of drop-in cellulosic biofuels fall enough to become competitive, then their expansion will not necessarily cause feedstock prices to rise. As long as local supplies of feedstocks that have no or low-valued alternative uses exist, then expansion will not cause prices to rise significantly. If cellulosic feedstocks come from dedicated biomass crops, then the supply curves will have a steeper slope because of competition for land. - Research highlights: → The likelihood of a significant cellulosic ethanol industry in the US looks dim. → Drop-in biofuels made from cellulosic feedstocks have a more promising future. → The spatial dimension of markets for cellulosic feedstocks will be limited. → Corn ethanol will be a tough competitor for cellulosic ethanol.

  8. Cerebral Angiographic Findings of Cosmetic Facial Filler-related Ophthalmic and Retinal Artery Occlusion

    Science.gov (United States)

    2015-01-01

    Cosmetic facial filler-related ophthalmic artery occlusion is rare but is a devastating complication, while the exact pathophysiology is still elusive. Cerebral angiography provides more detailed information on blood flow of ophthalmic artery as well as surrounding orbital area which cannot be covered by fundus fluorescein angiography. This study aimed to evaluate cerebral angiographic features of cosmetic facial filler-related ophthalmic artery occlusion patients. We retrospectively reviewed cerebral angiography of 7 patients (4 hyaluronic acid [HA] and 3 autologous fat-injected cases) showing ophthalmic artery and its branches occlusion after cosmetic facial filler injections, and underwent intra-arterial thrombolysis. On selective ophthalmic artery angiograms, all fat-injected patients showed a large filling defect on the proximal ophthalmic artery, whereas the HA-injected patients showed occlusion of the distal branches of the ophthalmic artery. Three HA-injected patients revealed diminished distal runoff of the internal maxillary and facial arteries, which clinically corresponded with skin necrosis. However, all fat-injected patients and one HA-injected patient who were immediately treated with subcutaneous hyaluronidase injection showed preserved distal runoff of the internal maxillary and facial arteries and mild skin problems. The size difference between injected materials seems to be associated with different angiographic findings. Autologous fat is more prone to obstruct proximal part of ophthalmic artery, whereas HA obstructs distal branches. In addition, hydrophilic and volume-expansion property of HA might exacerbate blood flow on injected area, which is also related to skin necrosis. Intra-arterial thrombolysis has a limited role in reconstituting blood flow or regaining vision in cosmetic facial filler-associated ophthalmic artery occlusions. PMID:26713062

  9. A thermodynamic investigation of the cellulose allomorphs: Cellulose(am), cellulose Iβ(cr), cellulose II(cr), and cellulose III(cr)

    International Nuclear Information System (INIS)

    Highlights: • Cellulose allomorphs were prepared and carefully characterized. • Measurements by oxygen bomb calorimetry, solution calorimetry, and by PPMS. • Thermodynamic properties for interconversion reactions of the cellulose allomorphs. • Review of the earlier literature with recalculation of property values. • Standard thermodynamic formation properties. - Abstract: The thermochemistry of samples of amorphous cellulose, cellulose I, cellulose II, and cellulose III was studied by using oxygen bomb calorimetry, solution calorimetry in which the solvent was cadoxen (a cadmium ethylenediamine solvent), and with a Physical Property Measurement System (PPMS) in zero magnetic field to measure standard massic heat capacities Cp,w∘ over the temperature range T = (2 to 302) K. The samples used in this study were prepared so as to have different values of crystallinity indexes CI and were characterized by X-ray diffraction, by Karl Fischer moisture determination, and by using gel permeation chromatography to determine the weight average degree of polymerization DPw. NMR measurements on solutions containing the samples dissolved in cadoxen were also performed in an attempt to resolve the issue of the equivalency or non-equivalency of the nuclei in the different forms of cellulose that were dissolved in cadoxen. While large differences in the NMR spectra for the various cellulose samples in cadoxen were not observed, one cannot be absolutely certain that these cellulose samples are chemically equivalent in cadoxen. Equations were derived which allow one to adjust measured property values of cellulose samples having a mass fraction of water wH2O to a reference value of the mass fraction of water wref. The measured thermodynamic properties (standard massic enthalpy of combustion ΔcHw∘, standard massic enthalpy of solution ΔsolHw∘, and Cp,w∘) were used in conjunction with the measured CI values to calculate values of the changes in the standard massic

  10. Abnormal origin of the ophthalmic artery from the anterior cerebral artery: Neuroradiological and intraoperative findings

    International Nuclear Information System (INIS)

    A 7-year old male child with an abnormal ophthalmic artery arising from the A1 segment of the anterior cerebral artery is described. The patient suffered growth inhibition which was thought to be caused by a craniobasal cystic lesion affecting the hypothalamus. Preoperative angiograms revealed no vascular abnormalities. The right ophthalmic artery, however, could not be identified. During resection of a large arachnoid cyst the ophthalmic artery was found to arise from the A1 segment of the anterior cerebral artery. To the best of our knowledge, this exact anomaly has not previously been reported. The clinical, neuroradiological and intraoperative findings are presented. (orig.)

  11. Advances in biomedical and pharmaceutical applications of functional bacterial cellulose-based nanocomposites.

    Science.gov (United States)

    Ullah, Hanif; Wahid, Fazli; Santos, Hélder A; Khan, Taous

    2016-10-01

    Bacterial cellulose (BC) synthesized by certain species of bacteria, is a fascinating biopolymer with unique physical and mechanical properties. BC's applications range from traditional dessert, gelling, stabilizing and thickening agent in the food industry to advanced high-tech applications, such as immobilization of enzymes, bacteria and fungi, tissue engineering, heart valve prosthesis, artificial blood vessels, bone, cartilage, cornea and skin, and dental root treatment. Various BC-composites have been designed and investigated in order to enhance its biological applicability. This review focuses on the application of BC-based composites for microbial control, wound dressing, cardiovascular, ophthalmic, skeletal, and endodontics systems. Moreover, applications in controlled drug delivery, biosensors/bioanalysis, immobilization of enzymes and cells, stem cell therapy and skin tissue repair are also highlighted. This review will provide new insights for academia and industry to further assess the BC-based composites in terms of practical applications and future commercialization for biomedical and pharmaceutical purposes. PMID:27312644

  12. Concepts for stereoselective acrylate insertion

    KAUST Repository

    Neuwald, Boris

    2013-01-23

    Various phosphinesulfonato ligands and the corresponding palladium complexes [{((PaO)PdMeCl)-μ-M}n] ([{( X1-Cl)-μ-M}n], (PaO) = κ2- P,O-Ar2PC6H4SO2O) with symmetric (Ar = 2-MeOC6H4, 2-CF3C6H4, 2,6-(MeO)2C6H3, 2,6-(iPrO)2C 6H3, 2-(2′,6′-(MeO)2C 6H3)C6H4) and asymmetric substituted phosphorus atoms (Ar1 = 2,6-(MeO)2C6H 3, Ar2 = 2′-(2,6-(MeO)2C 6H3)C6H4; Ar1 = 2,6-(MeO)2C6H3, Ar2 = 2-cHexOC 6H4) were synthesized. Analyses of molecular motions and dynamics by variable temperature NMR studies and line shape analysis were performed for the free ligands and the complexes. The highest barriers of ΔGa = 44-64 kJ/mol were assigned to an aryl rotation process, and the flexibility of the ligand framework was found to be a key obstacle to a more effective stereocontrol. An increase of steric bulk at the aryl substituents raises the motional barriers but diminishes insertion rates and regioselectivity. The stereoselectivity of the first and the second methyl acrylate (MA) insertion into the Pd-Me bond of in situ generated complexes X1 was investigated by NMR and DFT methods. The substitution pattern of the ligand clearly affects the first MA insertion, resulting in a stereoselectivity of up to 6:1 for complexes with an asymmetric substituted phosphorus. In the consecutive insertion, the stereoselectivity is diminished in all cases. DFT analysis of the corresponding insertion transition states revealed that a selectivity for the first insertion with asymmetric (P aO) complexes is diminished in the consecutive insertions due to uncooperatively working enantiomorphic and chain end stereocontrol. From these observations, further concepts are developed. © 2012 American Chemical Society.

  13. Microfibrillated cellulose: morphology and accessibility

    Energy Technology Data Exchange (ETDEWEB)

    Herrick, F.W.; Casebier, R.L.; Hamilton, J.K.; Sandberg, K.R.

    1983-01-01

    Microfibrillated cellulose (MFC) is prepared by subjecting dilute slurries of cellulose fibers to repeated high-pressure homogenizing action. A highly microfibrillated product will have a gel-like appearance at 2% concentration in water. Such gels have pseudoplastic viscosity properties and are very fluid when stirred at high shear rate. The relative viscosity of 2% MFC dispersions may be used as a measure of the degree of homogenization or microfibrillation of a given wood cellulose pulp. The water retention value of an MFC product can also be used as an indicator for degree of homogenization. Structurally, MFC appears to be a web of interconnected fibrils and microfibrils, the latter having diameters in the range 10-100 nm as observed in scanning and transmission electron micrographs. Chemical studies have revealed that MFC is only moderately degraded, while being greatly expanded in surface area. The accessibility of cellulose in MFC is only moderately degraded, while being greatly expanded in surface area. The accessibility of cellulose in MFC toward chemical reagents is greatly increased. Higher reactivity was demonstrated in dilute cupriethylenediamine solubility, triphenylmethylation, acetylation, periodate oxidation, and mineral acid and cellulase enzyme hydrolysis rates. 16 references, 8 figures, 7 tables.

  14. The cellulose synthase companion proteins act non-redundantly with CELLULOSE SYNTHASE INTERACTING1/POM2 and CELLULOSE SYNTHASE 6

    OpenAIRE

    Endler, Anne; Schneider, Rene; Kesten, Christopher; Edwin R Lampugnani; Persson, Staffan

    2016-01-01

    ABSTRACT Cellulose is a cell wall constituent that is essential for plant growth and development, and an important raw material for a range of industrial applications. Cellulose is synthesized at the plasma membrane by massive cellulose synthase (CesA) complexes that track along cortical microtubules in elongating cells of Arabidopsis through the activity of the protein CELLULOSE SYNTHASE INTERACTING1 (CSI1). In a recent study we identified another family of proteins that also are associated ...

  15. A NOVEL OPHTHALMIC DRUG DELIVERY SYSTEM: IN-SITU GEL

    Directory of Open Access Journals (Sweden)

    A.P. Patil*, A.A. Tagalpallewar, G.M. Rasve, A.V. Bendre, P.G. Khapekar

    2012-09-01

    Full Text Available The ophthalmic in-situ gels now days proved an palpable sustained drug delivery in various eye diseases. The formulation of in-situ gels for eye which carries the advantages like easy for administration, reduces frequency of dose and improves patient compliance. The formation of in-situ gels depends on phase transition system or sol-gel transition system. The formulation approaches like temperature intonation, pH change and presence of ions from which the drug gets released in a sustained and controlled manner are utilised for in-situ gels. Various polymers that are used for the formulation of in-situ gels include chitosan, Pluronic F-127, poly-caprolactone, gellan gum, alginic acid, xyloglucan, pectin etc.

  16. Neuro-ophthalmic manifestation of neuromyelitis optica spectrum disorders

    Directory of Open Access Journals (Sweden)

    Xiao-jun ZHANG

    2014-10-01

    Full Text Available Neuromyelitis optica spectrum disorders (NMOSDs include classic neuromyelitis optica (NMO, opticospinal multiple sclerosis (OSMS, limited form of NMO and isolated optic neuritis or myelitis accompanied by either systemic autoimmune diseases or typical MRI findings of NMO. The common neuro-ophthalmic features of NMOSDs include simultaneous or consecutive bilateral optic neuritis, more commonly seen optic disk edema and surrounding exudate, poor visual recovery, steroid responsiveness and dependency. Combined with serum aquaporin 4 (AQP4 antibody and brain MRI examination, these clinical features can be helpful to the early differential diagnosis between NMOSDs and MS. Some types of eye movement abnormalities have been reported in patients with NMOSDs, but further investigation needs to be done before the specificity of these features are confirmed. doi: 10.3969/j.issn.1672-6731.2014.10.003

  17. Surface dose rate calibration of Sr-90 plane ophthalmic applicators

    International Nuclear Information System (INIS)

    Calibration of an imported strontium-90 ophthalmic applicator at the U.S. National Bureau of Standards (now the National Institute of Standards and Technology) has disclose a significant discrepancy in dose rate calibration (32%-35%) with that quoted by the manufacturer. The University of Wisconsin has investigated this discrepancy and found that both laboratories use similar techniques and a version of the Bragg-Gray equation to yield dose rate estimates. Experimental results indicate a strong relationship between the size of the collecting electrode used in the extrapolation chamber and the resulting estimate of absorbed dose rate. Calibration of these applicators is reviewed and suggestions for improvement and further research are proposed

  18. Irradiation of choroidal melanoma with iodine 125 ophthalmic plaque

    International Nuclear Information System (INIS)

    Radioactive iodine 125 is a low-energy γ isotope with physical characteristics suitable for irradiation of intraocular tumors. Metal ophthalmic applicators have been designed to shield vital ocular structures while allowing irradiation of the tumor. We compared the radiation effects of iodine 125 and cobalt 60. The Greene melanoma was transplanted into the suprachoroidal space of rabbits. The tumor then grew as an intraocular mass, was irradiated, and was followed up for two months before enucleation. Histopathologic examiation defined the extent of the radiation damage to the tumor and other ocular structures from the iodine 125 and from the cobalt 60. The eye irradiated with iodine 125 suffered minimal radiation damage, whereas the tumor was sterilized. The eye irradiated with cobalt 60 showed substantial radiation damage, and the melanoma was incompletely treated. Our results support the use of iodine 125 in treating intraocular tumors. More research is needed as to optimum total dose and dose rate

  19. Monte Carlo dosimetry of I-125 ophthalmic plaques

    International Nuclear Information System (INIS)

    I-125 seeds, mounted on the surface of gold-alloy plaques (1.0 to 2.0 cm in diameter), are used to treat intraocular malignancies. Currently available dose-computation algorithms ignore the perturbing influence of the plaque, assuming the seeds to be immersed in an infinite, homogeneous medium. The authors used a theoretical but physically and geometrically realistic approach, the Monte Carlo method, to calculate the absorbed dose in water arising from I-125 seeds backed by ophthalmic plaques. Preliminary results indicate that the plaque enhances dose by 2% very close to the seed and reduces dose by 4% to 7% at distances beyond 1 cm. Results are presented for various plaque dimensions, alloy compositions, and I-125 seed types in current clinical use

  20. A Case of Hydranencephaly in Which Ophthalmic Examinations Were Performed

    Directory of Open Access Journals (Sweden)

    Shohei Eda

    2016-09-01

    Full Text Available Purpose: We performed ophthalmic examinations, including optical coherence tomography (OCT, on a case diagnosed with hydranencephaly. Case Report: This case involved a female infant born at the gestational age of 35 weeks and 4 days, with the birth weight of 2,152 g, who was one of monochorionic diamniotic twins, and the identical twin died in utero at the gestational age of 24 weeks. After that, examination by fetal echo indicated that she had microcephaly and ventriculomegaly. Postnatal magnetic resonance imaging (MRI of her head indicated microcephaly and significant enlargement of the lateral ventricle on both sides, with no obvious signs of elevated intracranial pressure. The brain parenchyma of both sides of the frontal lobe, parietal lobe, and occipital lobe had marked thinning, yet that of the temporal lobe, basal ganglia, thalamus, brain stem, and cerebellum had been maintained. Moreover, no obvious hematoma or neoplastic lesions were observed. Ophthalmic examinations indicated that both of her eyes had slight light reflex, attributed to optic nerve atrophy. Examination by use of a hand-held OCT system indicated a layered structure of the retina and thinning of the ganglion cell layer. Flicker electroretinogram (ERG examination by use of a hand-held ERG system indicated an almost normal wave. However, no clear visual reaction was observed when she was 10 months old. Conclusion: Our findings in this case of hydranencephaly revealed that even though the outer layer functions of the patient’s retina were maintained, extensive damage to her cerebral cortex resulted in poor visual function.

  1. Interferon related ophthalmic complications in patients of hepatitis C

    International Nuclear Information System (INIS)

    To determine the frequency of ophthalmic complications of interferon-alpha 2b and ribavirin combination therapy in patients of chronic hepatitis C. Study Design: Quasi experimental study. Place and Duration of the Study: Eye and Medical Department of Military Hospital Rawalpindi and Combined Military Hospital Peshawar, Pakistan from Jan 2010 to Jan 2011. Patients and Methods: A total of 93 diagnosed and consenting cases of hepatitis C were recruited who were eligible for interferon therapy. They were administered 3 million units (mu) interferon (INF)-alpha 2b, subcutaneously thrice a week along with 800 mg of ribavirin orally daily for 6 months. Ocular examination of all the patients was performed before starting interferon and then monthly afterwards till the completion of interferon therapy. Their ocular complications were observed and recorded. Results: The study included 54 (58%) males and 39 (42%) females. Mean age of the patients was 40.59 +- 8.68 years. Ocular complications developed in 24 (25.8%) out of 93 patients. Retinal icroaneurysms were present in 5 (5.4%), cotton wool spots in 10 (10.8%), retinal hemorrhages in 8 (8.6%) and optic disc hyperaemia in 1 (1.1%) patient. These complications developed within 8-12 weeks after start of INF therapy. Conclusion: Interferon alpha-2b and ribavirin combination therapy is characterized by its ophthalmic complications which are usually benign and self limiting. In our study, ocular complications which include retinal microaneurysms, cotton wool spots, retinal haemorrhages and optic disc hyperaemia developed in 25.8% of patients. In two third of these cases, these complications resolved before completion of INF therapy. (author)

  2. Clinical, Pharmacokinetic, and In Vitro Studies to Support Bioequivalence of Ophthalmic Drug Products.

    Science.gov (United States)

    Choi, Stephanie H; Lionberger, Robert A

    2016-07-01

    For ophthalmic drug products, the determination of bioequivalence can be challenging, as drug concentrations at the site of action cannot always be measured. The FDA has recommended a variety of studies that can be used to demonstrate bioequivalence for different ophthalmic drug products. Product-specific bioequivalence recommendations for 28 ophthalmic products have been posted on FDA's website as of May 2016, outlining the specific tests which should be performed to demonstrate bioequivalence. The type of study that can be used to demonstrate bioequivalence depends on the drug product's active pharmaceutical ingredient(s), dosage form, indication, site of action, mechanism of action, and scientific understanding of drug release/drug availability and drug product characteristics. This article outlines the FDA's current guidance on studies to demonstrate bioequivalence through clinical endpoint studies, pharmacokinetic studies, and in vitro studies for generic ophthalmic drug products. PMID:27184578

  3. Ophthalmic artery color Doppler ultrasonography in mild-to-moderate preeclampsia

    Energy Technology Data Exchange (ETDEWEB)

    Ayaz, Tunahan; Akansel, Gur. E-mail: gakansel@superonline.com; Hayirlioglu, Alper; Arslan, Arzu; Suer, Necdet; Kuru, Ihsan

    2003-06-01

    Objective: To evaluate the hemodynamic changes in mild-moderate preeclampsia using ophthalmic artery Doppler ultrasonography technique. Methods: Ophthalmic artery pulsatility and resistivity indices were calculated in 30 mild-moderate preeclamptic women and 30 normotensive gravid women of matched gestational age. Student's t-test was performed to test the significance of difference. Results: Both indices of peripheral resistance were found to be significantly lower in the ophthalmic arteries of mild-moderately preeclamptic women than those measured in normotensive gravid women at similar stage of pregnancy. In a small number patients whose disease progressed to severe preeclampsia, both indices increased. Conclusion: In patients with mild-moderate preeclampsia, ophthalmic artery color Doppler ultrasonography detects hemodynamic changes that are not present in normotensive gravid women. Reversal of Doppler patterns in a small number of patients with progressive disease supports the hypotheses suggesting the presence of early vasodilation and late vasospasm in the etiology of preeclampsia.

  4. In vitro testing of thiolated poly(aspartic acid) from ophthalmic formulation aspects.

    Science.gov (United States)

    Budai-Szű Cs, Mária; Horvát, Gabriella; Gyarmati, Benjámin; Szilágyi, Barnabás Áron; Szilágyi, András; Csihi, Tímea; Berkó, Szilvia; Szabó-Révész, Piroska; Mori, Michela; Sandri, Giuseppina; Bonferoni, Maria Cristina; Caramella, Carla; Csányi, Erzsébet

    2016-08-01

    Ocular drug delivery formulations must meet anatomical, biopharmaceutical, patient-driven and regulatory requirements. Mucoadhesive polymers can serve as a better alternative to currently available ophthalmic formulations by providing improved bioavailability. If all requirements are addressed, a polymeric formulation resembling the tear film of the eye might be the best solution. The optimum formulation must not have high osmotic activity, should provide appropriate surface tension, pH and refractive index, must be non-toxic and should be transparent and mucoadhesive. We would like to highlight the importance of in vitro polymer testing from a pharmaceutical aspect. We, therefore, carried out physical-chemical investigations to verify the suitability of certain systems for ophthalmic formulations. In this work, in situ gelling, mucoadhesive thiolated poly(aspartic acid)s were tested from ophthalmic formulation aspects. The results of preformulation measurements indicate that these polymers can be used as potential carriers in ophthalmic drug delivery. PMID:26556306

  5. Internal Clinical Acceptance Test of the Dose Rate of 106Ru/106Rh Ophthalmic Applicators

    International Nuclear Information System (INIS)

    Episcleral brachytherapy using 106Ru/106Rh ophthalmic applicators is a proven method of therapy for uveal melanomas, sparing the globe and in many cases, conserving vision. In its certificates, Bebig, the manufacturer of the product, indicates a dose rate for the 106Ru/106Rh ophthalmic applicators which ensures traceability to the NIST standard (12/2001). Since the introduction of the NIST calibration, the quality of the calibration provided by Bebig to the clinical user has been examined for 45 ophthalmic applicators with a plastic scintillator measurement system. Of these, 20 ophthalmic applicators had a dose rate at the dose specification reference point that exceeded the dose rate stated in the manufacturer's certificate by up to 23%. (author)

  6. Ophthalmic artery color Doppler ultrasonography in mild-to-moderate preeclampsia

    International Nuclear Information System (INIS)

    Objective: To evaluate the hemodynamic changes in mild-moderate preeclampsia using ophthalmic artery Doppler ultrasonography technique. Methods: Ophthalmic artery pulsatility and resistivity indices were calculated in 30 mild-moderate preeclamptic women and 30 normotensive gravid women of matched gestational age. Student's t-test was performed to test the significance of difference. Results: Both indices of peripheral resistance were found to be significantly lower in the ophthalmic arteries of mild-moderately preeclamptic women than those measured in normotensive gravid women at similar stage of pregnancy. In a small number patients whose disease progressed to severe preeclampsia, both indices increased. Conclusion: In patients with mild-moderate preeclampsia, ophthalmic artery color Doppler ultrasonography detects hemodynamic changes that are not present in normotensive gravid women. Reversal of Doppler patterns in a small number of patients with progressive disease supports the hypotheses suggesting the presence of early vasodilation and late vasospasm in the etiology of preeclampsia

  7. Microbial Cellulose Assembly in Microgravity

    Science.gov (United States)

    Brown, R. Malcolm, Jr.

    1998-01-01

    Based on evidence indicating a possible correlation between hypo-gravity conditions and alteration of cellulose production by the gram negative bacterium, Acetobacter xylinum, a ground-based study for a possible long term Space Shuttle flight has been conducted. The proposed experiment for A. xylinum aboard the Shuttle is the BRIC (Biological Research in a Canister), a metal container containing spaces for nine Petri plates. Using a common experimental design, the cellulose production capability as well as the survivability of the A. xylinum strains NQ5 and AY201 have been described. It should now be possible to use the BRIC for the first long term microgravity experiments involving the biosynthesis of cellulose.

  8. Characterization of Cellulose Synthesis in Plant Cells

    Directory of Open Access Journals (Sweden)

    Samaneh Sadat Maleki

    2016-01-01

    Full Text Available Cellulose is the most significant structural component of plant cell wall. Cellulose, polysaccharide containing repeated unbranched β (1-4 D-glucose units, is synthesized at the plasma membrane by the cellulose synthase complex (CSC from bacteria to plants. The CSC is involved in biosynthesis of cellulose microfibrils containing 18 cellulose synthase (CesA proteins. Macrofibrils can be formed with side by side arrangement of microfibrils. In addition, beside CesA, various proteins like the KORRIGAN, sucrose synthase, cytoskeletal components, and COBRA-like proteins have been involved in cellulose biosynthesis. Understanding the mechanisms of cellulose biosynthesis is of great importance not only for improving wood production in economically important forest trees to mankind but also for plant development. This review article covers the current knowledge about the cellulose biosynthesis-related gene family.

  9. Characterization of Cellulose Synthesis in Plant Cells.

    Science.gov (United States)

    Maleki, Samaneh Sadat; Mohammadi, Kourosh; Ji, Kong-Shu

    2016-01-01

    Cellulose is the most significant structural component of plant cell wall. Cellulose, polysaccharide containing repeated unbranched β (1-4) D-glucose units, is synthesized at the plasma membrane by the cellulose synthase complex (CSC) from bacteria to plants. The CSC is involved in biosynthesis of cellulose microfibrils containing 18 cellulose synthase (CesA) proteins. Macrofibrils can be formed with side by side arrangement of microfibrils. In addition, beside CesA, various proteins like the KORRIGAN, sucrose synthase, cytoskeletal components, and COBRA-like proteins have been involved in cellulose biosynthesis. Understanding the mechanisms of cellulose biosynthesis is of great importance not only for improving wood production in economically important forest trees to mankind but also for plant development. This review article covers the current knowledge about the cellulose biosynthesis-related gene family. PMID:27314060

  10. Resistance to fluoroquinolones and methicillin in ophthalmic isolates of Staphylococcus pseudintermedius from companion animals

    OpenAIRE

    Kang, Min-Hee; Chae, Min-Joo; Yoon, Jang-Won; Lee, So-Young; Yoo, Jong-Hyun; Park, Hee-Myung

    2014-01-01

    Resistance to fluoroquinolones and methicillin was determined for 49 ophthalmic isolates of Staphylococcus pseudintermedius from dogs with and without ophthalmic disease. Resistance was observed for ciprofloxacin (40.8%), ofloxacin (38.8%), enrofloxacin (38.8%), levofloxacin (34.7%), and moxifloxacin (4.1%). Eighteen isolates, 16 of which were resistant to oxacillin, were mecA-positive. Nine of the 16 oxacillin-resistant mecA-positive S. pseudintermedius isolates were resistant to more than o...

  11. Antibiotic resistance and molecular characterization of ophthalmic Staphylococcus pseudintermedius isolates from dogs

    OpenAIRE

    Kang, Min-Hee; Chae, Min-Joo; Yoon, Jang-Won; Kim, Seung-Gon; Lee, So-Young; Yoo, Jong-Hyun; Park, Hee-Myung

    2014-01-01

    The prevalence, virulence potential, and antibiotic resistance of ophthalmic Staphylococcus pseudintermedius (SP) isolated from dogs were examined. Sixty-seven Staphylococcus species were isolated from ophthalmic samples and surveyed for species-specific sequences in the Staphylococcus intermedius group (SIG) nuclease gene (SInuc), exfoliative toxin gene for SIG (siet), and antibiotic resistance genes (blaZ and mecA). PCR-restriction fragment length polymorphism analysis of the pta gene was a...

  12. Aneurysm and infundibular dilatation at an unusual origin of the ophthalmic artery

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun Soo; Kim, Eui Jong; Lee, Kyung Mi; Choi, Woo Suk [Dept. of Radiology, Kyung Hee University Hospital, Seoul (Korea, Republic of)

    2014-10-15

    The ophthalmic artery usually arises from the anteromedial or superomedial aspect of the internal carotid artery. Rarely does it arise from the medial or posteromedial aspect of the internal carotid artery. In this paper, the authors report two cases of aneurysm and infundibular dilatation found at unusual sites of origin in the ophthalmic artery and review the literature about possible etiologies contributing to the anatomic variations.

  13. The assessment of visually impaired persons working capacities using electrophysiological and ophthalmic ergonomics methods

    OpenAIRE

    M. I. Razumovsky; O. E. Kolyuka; A. M. Razumovskaya

    2014-01-01

    Aim was to analyze working capacities of visually impaired persons by means of complex electrophysiological and ophthalmic ergonomics eye examination.Materials and methods. Standard clinical ophthalmologic examination (visual acuity measurement, refractometry, biomicroscopy, ophthalmoscopy) as well as electrophysiological (electrooculography, electrical sensitivity of the eye, critical flicker fusion frequency) and ophthalmic ergonomics tests (accommodation measurement, professional testing u...

  14. Aneurysm and infundibular dilatation at an unusual origin of the ophthalmic artery

    International Nuclear Information System (INIS)

    The ophthalmic artery usually arises from the anteromedial or superomedial aspect of the internal carotid artery. Rarely does it arise from the medial or posteromedial aspect of the internal carotid artery. In this paper, the authors report two cases of aneurysm and infundibular dilatation found at unusual sites of origin in the ophthalmic artery and review the literature about possible etiologies contributing to the anatomic variations.

  15. Chemical modification of cellulose for electrospinning applications

    OpenAIRE

    Martín Ferrer, Elena

    2013-01-01

    The aim of the thesis is to develop technology for producing cellulose fatty acid esters that later will be used to produce fibrous materials by means of electrospinning. Main material of the study is cellulose-stearate which is a polymer synthesised by reaction between stearoyl chloride and cellulose. The experimental part consists of synthesis of it by chemical modification of cellulose using ionic liquid as a reaction media. In addition, ionic liquid is also synthesised from the beginning....

  16. Filtration properties of bacterial cellulose membranes

    OpenAIRE

    Lehtonen, Janika

    2015-01-01

    Bacterial cellulose has the same molecular formula as cellulose from plant origin, but it is characterized by several unique properties including high purity, crystallinity and mechanical strength. These properties are dependent on parameters such as the bacterial strain used, the cultivation conditions and post-growth processing. The possibility to achieve bacterial cellulose membranes with different properties by varying these parameters could make bacterial cellulose an interesting materi...

  17. Biocompatibility of Bacterial Cellulose Based Biomaterials

    OpenAIRE

    Omar P. Troncoso; Solene Commeaux; Torres, Fernando G.

    2012-01-01

    Some bacteria can synthesize cellulose when they are cultivated under adequate conditions. These bacteria produce a mat of cellulose on the top of the culture medium, which is formed by a three-dimensional coherent network of pure cellulose nanofibers. Bacterial cellulose (BC) has been widely used in different fields, such as the paper industry, electronics and tissue engineering due to its remarkable mechanical properties, conformability and porosity. Nanocomposites based on BC have received...

  18. A Molecular Description of Cellulose Biosynthesis

    OpenAIRE

    McNamara, Joshua T.; Morgan, Jacob L.W.; Zimmer, Jochen

    2015-01-01

    Cellulose is the most abundant biopolymer on Earth, and certain organisms from bacteria to plants and animals synthesize cellulose as an extracellular polymer for various biological functions. Humans have used cellulose for millennia as a material and an energy source, and the advent of a lignocellulosic fuel industry will elevate it to the primary carbon source for the burgeoning renewable energy sector. Despite the biological and societal importance of cellulose, the molecular mechanism by ...

  19. Electrically conductive bacterial cellulose composite membranes produced by the incorporation of graphite nanoplatelets in pristine bacterial cellulose membranes

    Directory of Open Access Journals (Sweden)

    T. Zhou

    2013-09-01

    Full Text Available Graphite nanoplatelets (GNPs were utilized to improve the electrical conductivity of pristine bacterial cellulose (BC membranes. By physical and chemical methods, flake-shaped GNPs, weaving through the surface layer of web-like cellulose nanofibrils, were indeed fixed or trapped by the adjacent nanofibrils in the BC surface network, for comparison, rod-shaped multi-walled carbon nanotubes (MWCNTs were homogeneously inserted into BC membrane through the pore structures and tunnels within the BC membrane. Strong physical and chemical interaction exists between the BC nanofibrils and the particles of GNP or MWCNT even after 15 h sonication. BC membrane with 8.7 wt% incorporated GNPs reached the maximum electrical conductivity of 4.5 S/cm, while 13.9 wt% MWCNT/BC composite membrane achieved the maximum electrical conductivity of 1.2 S/cm. Compared with one dimensional (1-D MWCNTs, as long as GNPs inserted into BC membranes, the 2-D reinforcement of GNPs was proven to be more effective in improving the electrical conductivity of BC membranes thus not only break the bottleneck of further improvement of the electrical conductivity of BC-based composite membranes but also broaden the applications of BC and GNPs.

  20. The trafficking and behavior of cellulose synthase and a glimpse of potential cellulose synthesis regulators

    Institute of Scientific and Technical Information of China (English)

    Logan BASHLINE; Juan DU; Ying GU

    2011-01-01

    Cellulose biosynthesis is a topic of intensive research not only due to the significance of cellulose in the integrity of plant cell walls,but also due to the potential of using cellulose,a natural carbon source,in the production ot biofuels.Characterization of the composition,regulation,and trafficking of cellulose synthase complexes (CSCs) is critical to an understanding of cellulose biosynthesis as well as the characterization of additional proteins that contribute to the production of cellulose either through direct interactions with CSCs or through indirect mechanisms.In this review,a highlight of a few proteins that appear to affect cellulose biosynthesis,which includes:KORRIGAN (KOR),Cellulose Synthase-Interactive Protein 1 (CSI1),and the poplar microtubule-associated protein,PttMAP20,will accompany a description of cellulose synthase (CESA) behavior and a discussion of CESA trafficking compartments that might act in the regulation of cellulose biosynthesis.

  1. Adsorption and desorption of cellulose derivatives.

    NARCIS (Netherlands)

    Hoogendam, C.W.

    1998-01-01

    Cellulose derivatives, in particular carboxymethyl cellulose (CMC) are used in many (industrial) applications. The aim of this work is to obtain insight into the adsorption mechanism of cellulose derivatives on solid-liquid interfaces.In chapter 1 of this thesis we discuss some appl

  2. Iodine catalyzed acetylation of starch and cellulose

    Science.gov (United States)

    Starch and cellulose, earth's most abundant biopolymers, are of tremendous economic importance. Over 90% of cotton and 50% of wood are made of cellulose. Wood and cotton are the major resources for all cellulose products such as paper, textiles, construction materials, cardboard, as well as such c...

  3. Bioengineering cellulose-hemicellulose networks in plants

    NARCIS (Netherlands)

    Obembe, O.

    2006-01-01

    The interactions between cellulose and hemicellulose in the cell walls are important in the industrial application of the cellulose (natural) fibres. We strive to modify these interactions (i) by interfering with cellulose biosynthesis and (ii) by direct interference of the

  4. Vasculature of the ophthalmic rete in night herons (Nycticorax nycticorax): scanning electron microscopy of corrosion casts.

    Science.gov (United States)

    Ninomiya, Hiroyoshi

    2002-09-01

    Vasculature of the ophthalmic rete (rete ophthalmicum) in the night heron (Nycticorax nycticorax) was studied using scanning electron microscopy of vascular corrosion casts and light microscopy on tissue sections. Most blood to the eyeball and a lesser volume of blood to the brain passed through the ophthalmic rete via the external ophthalmic artery. The collateral retial arterioles originated from the external ophthalmic artery forming a flat and fusiform-shaped arterial network at the ventrotemporal region of the eyeball. The arterial network was intermixed with a similar complex of the veins from the eye. The ophthalmotemporal artery, which supplied the eyeball posteriorly, and supraorbital and infraorbital arteries, which supplied the eyeball anteriorly, originated from the rete. Blood from the eye, which is a site of potential heat loss, drained into the ophthalmic rete via the ophthalmotemporal vein. On the casts of retial arterioles, slit-like cleavages at branching sites representing flap valves, which might play a role as sluice valves, were seen. In addition, marks of circularly running grooves, which might represent tufts of smooth muscle cells and might contribute to a sphincter activity, were observed. These anatomical specializations of the avian ophthalmic rete, involving parallel arrangement of arteries and veins, may function to facilitate counter-current heat exchange and to regulate blood pressure and volume to the eye and the brain. PMID:12236865

  5. The first LHC insertion quadrupole

    CERN Multimedia

    2004-01-01

    An important milestone was reached in December 2003 at the CERN Magnet Assembly Facility. The team from the Accelerator Technology - Magnet and Electrical Systems group, AT-MEL, completed the first special superconducting quadrupole for the LHC insertions which house the experiments and major collider systems. The magnet is 8 metres long and contains two matching quadrupole magnets and an orbit corrector, a dipole magnet, used to correct errors in quadrupole alignment. All were tested in liquid helium and reached the ultimate performance criteria required for the LHC. After insertion in the cryostat, the superconducting magnet will be installed as the Q9 quadrupole in sector 7-8, the first sector of the LHC to be put in place in 2004. Members of the quadrupole team, from the AT-MEL group, gathered around the Q9 quadrupole at its inauguration on 12 December 2003 in building 181.

  6. Insertion device calculations with mathematica

    Energy Technology Data Exchange (ETDEWEB)

    Carr, R. [Stanford Synchrotron Radiation Lab., CA (United States); Lidia, S. [Univ. of California, Davis, CA (United States)

    1995-02-01

    The design of accelerator insertion devices such as wigglers and undulators has usually been aided by numerical modeling on digital computers, using code in high level languages like Fortran. In the present era, there are higher level programming environments like IDL{reg_sign}, MatLab{reg_sign}, and Mathematica{reg_sign} in which these calculations may be performed by writing much less code, and in which standard mathematical techniques are very easily used. The authors present a suite of standard insertion device modeling routines in Mathematica to illustrate the new techniques. These routines include a simple way to generate magnetic fields using blocks of CSEM materials, trajectory solutions from the Lorentz force equations for given magnetic fields, Bessel function calculations of radiation for wigglers and undulators and general radiation calculations for undulators.

  7. Ionic Liquids and Cellulose: Dissolution, Chemical Modification and Preparation of New Cellulosic Materials

    Directory of Open Access Journals (Sweden)

    Mehmet Isik

    2014-07-01

    Full Text Available Due to its abundance and a wide range of beneficial physical and chemical properties, cellulose has become very popular in order to produce materials for various applications. This review summarizes the recent advances in the development of new cellulose materials and technologies using ionic liquids. Dissolution of cellulose in ionic liquids has been used to develop new processing technologies, cellulose functionalization methods and new cellulose materials including blends, composites, fibers and ion gels.

  8. Impact of Biofield Treatment on Chemical and Thermal Properties of Cellulose and Cellulose Acetate

    OpenAIRE

    Trivedi, Mahendra Kumar

    2015-01-01

    Cellulose being an excellent biopolymer has cemented its place firmly in many industries as a coating material, textile, composites, and biomaterial applications. In the present study, we have investigated the effect of biofield treatment on physicochemical properties of cellulose and cellulose acetate. The cellulose and cellulose acetate were exposed to biofield and further the chemical and thermal properties were investigated. X-ray diffraction study asserted that the biofield treatment did...

  9. Graphene oxide/cellulose aerogels nanocomposite: Preparation, pyrolysis, and application for electromagnetic interference shielding.

    Science.gov (United States)

    Wan, Caichao; Li, Jian

    2016-10-01

    Hybrid aerogels consisting of graphene oxide (GO) and cellulose were prepared via a solution mixing-regeneration-freeze drying process. The presence of GO affected the micromorphology of the hybrid aerogels, and a self-assembly behavior of cellulose was observed after the incorporation of GO. Moreover, there is no remarkable modification in the crystallinity index and thermal stability after the insertion of GO. After the reduction of GO in the hybrid aerogels by l-ascorbic acid and the subsequent pyrolysis of the aerogels, the resultant displays some interesting characteristics, including good electromagnetic interference (EMI) shielding capacity (SEtotal=58.4dB), high electrical conductivity (19.1Sm(-1)), hydrophobicity, and fire resistance, which provide an opportunity for some advanced applications such as EMI protection, electrochemical devices, water-proofing agents, and fire retardants. Moreover, this work possibly helps to facilitate the development of both cellulose and GO-based materials and expand their application scope. PMID:27312627

  10. ATLAS insertable B-layer

    Czech Academy of Sciences Publication Activity Database

    Marčišovský, Michal

    2011-01-01

    Roč. 633, č. 1 (2011), "S224"-"S225". ISSN 0168-9002. [International workshop on radiation imaging detector s /11./. Praha, 26.06.2009-02.07.2009] R&D Projects: GA MŠk LA08015; GA MŠk LA08032 Institutional research plan: CEZ:AV0Z10100502 Keywords : ATLAS * pixel detector * insertable B-layer Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 1.207, year: 2011

  11. Vacuum guidelines for ISA insertions

    International Nuclear Information System (INIS)

    Vacuum requirements place design restrictions on the ISA insertions. The vacuum tube diameter, given a distance L between pumps, is determined by the desorption of molecules from the wall under the impact of ions created by the beam, whereas the thickness of the tube must be sufficient to prevent collapse. In addition, the entire vacuum chamber must be able to be baked out at approximately 2000C

  12. HTS Insert Magnet Design Study

    CERN Document Server

    Devaux, M; Fleiter, J; Fazilleau, P; Lécrevisse, T; Pes, C; Rey, J-M; Rifflet, J-M; Sorbi, M; Stenvall, A; Tixador, P; Volpini, G

    2011-01-01

    Future accelerator magnets will need to reach higher field in the range of 20 T. This field level is very difficult to reach using only Low Temperature Superconductor materials whereas High Temperature Superconductors (HTS) provide interesting opportunities. High current densities and stress levels are needed to design such magnets. YBCO superconductor indeed carries large current densities under high magnetic field and provides good mechanical properties especially when produced using the IBAD approach. The HFM EUCARD program studies the design and the realization of an HTS insert of 6 T inside a Nb3Sn dipole of 13T at 4.2 K. In the2HTS insert, engineering current densities higher than 250 MA/m under 19 T are required to fulfill the specifications. The stress level is also very severe. YBCO IBAD tapes theoretically meet these challenges from presented measurements. The insert protection is also a critical because HTS materials show low quench propagation velocities and the coupling with the Nb3Sn magnet make...

  13. High performance cellulose nanocomposites: comparing the reinforcing ability of bacterial cellulose and nanofibrillated cellulose

    OpenAIRE

    Lee, K. Y.; Tammelin, T.; Schulfter, K.; Kiiskinen, H.; Samela, J.; Bismarck, A.

    2012-01-01

    This work investigates the surface and bulk properties of nanofibrillated cellulose (NFC) and bacterial cellulose (BC), as well as their reinforcing ability in polymer nanocomposites. BC possesses higher critical surface tension of 57 mN m(-1) compared to NFC (41 mN m(-1)). The thermal degradation temperature in both nitrogen and air atmosphere of BC was also found to be higher than that of NFC. These results are in good agreement with the higher crystallinity of BC as determined by XRD, meas...

  14. DEVELOPMENT AND IN-VITRO CHARACTERIZATION OF OCULAR INSERT CONTAINING ERYTHROMYCIN

    Directory of Open Access Journals (Sweden)

    Kaul Shweta

    2012-08-01

    Full Text Available Ocular drug delivery is one of the most fascinating and challenging tasks being faced by the Pharmaceutical researchers. The challenges to the formulator are to circumvent the protective barriers of the eye without causing permanent tissue damage, maintain a therapeutic level at the site of action for prolonged period of time. The eye drop dosage form is easy to instill but suffers the drawback of getting the medication immediately diluted in the tear film as soon it is instilled into the cul-de-sac and is rapidly drained away, therefore, only a very small fraction of the instilled dose is absorbed into the target tissues. The frequent periodic instillation of eye drops becomes necessary to maintain a continuous sustained level of medication, which may lead to systemic side effects. Frequent dosing of large doses of drug becomes necessary to achieve the therapeutic objective which often results in corresponding increase in local and systemic side effects. So research on Novel ophthalmic drug delivery systems is in progress to overcome all these disadvantages of conventional ophthalmic dosage forms. In the present study, efforts were made for designing and evaluating Erythromycin ocular inserts. Erythromycin, a macrolide antibiotic is highly useful for the treatment of trachoma, conjunctivitis and keratitis. Erythromycin suffered the disadvantage of instillation as it is available as 0.5% w/w ointment to be placed in eye 6 times a day and hence maximized patient non compliance, leading to ineffective therapy. Various batches of Erythromycin ocular inserts were prepared by solvent casting method using HPMC- K4M, PVP K30 and MC as polymers and PEG-400 as plasticizer. The formulated ocuserts were then evaluated for their average weight variation, thickness, folding endurance, swelling index, drug content, in-vitro drug release.

  15. Production of bacterial cellulose from alternate feedstocks

    Energy Technology Data Exchange (ETDEWEB)

    D. N. Thompson; M. A. Hamilton

    2000-05-07

    Production of bacterial cellulose by Acetobacter xylinum ATCC 10821 and 23770 in static cultures was tested from unamended food process effluents. Effluents included low- and high-solids potato effluents (LS and HS), cheese whey permeate (CW), and sugar beet raffinate (CSB). Strain 23770 produced 10% less cellulose from glucose than did 10821, and diverted more glucose to gluconate. Unamended HS, CW, and CSB were unsuitable for cellulose production by either strain, while LS was unsuitable for production by 10821. However, 23770 produced 17% more cellulose from LS than from glucose, indicating unamended LS could serve as a feedstock for bacterial cellulose.

  16. Production of Bacterial Cellulose from Alternate Feedstocks

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, David Neil; Hamilton, Melinda Ann

    2000-05-01

    Production of bacterial cellulose by Acetobacter xylinum ATCC 10821 and 23770 in static cultures was tested from unamended food process effluents. Effluents included low- and high-solids potato effluents (LS & HS), cheese whey permeate (CW), and sugar beet raffinate (CSB). Strain 23770 produced 10% less cellulose from glucose than did 10821, and diverted more glucose to gluconate. Unamended HS, CW, and CSB were unsuitable for cellulose production by either strain, while LS was unsuitable for production by 10821. However, 23770 produced 17% more cellulose from LS than from glucose, indicating unamended LS could serve as a feedstock for bacterial cellulose.

  17. The Perspectives for Genetically Modified Cellulosic Ethanol in the Czech Republic

    OpenAIRE

    Blahova, Pavla; Janda, Karel; Kristoufek, Ladislav

    2014-01-01

    This paper connects the biofuels literature with genetic modifications literature by considering the potential of genetic modifications for increasing the efficiency of cellulosic biofuels production. This is done for one particular case through analyzing the effect of genetically modified corn adoption on overall yields of corn for silage. Our econometric model confirms that the use of genetically modified corn with inserted MON810 gene increases the overall corn biomass yield in the product...

  18. Cellulose nanomaterials in water treatment technologies.

    Science.gov (United States)

    Carpenter, Alexis Wells; de Lannoy, Charles-François; Wiesner, Mark R

    2015-05-01

    Cellulose nanomaterials are naturally occurring with unique structural, mechanical and optical properties. While the paper and packaging, automotive, personal care, construction, and textiles industries have recognized cellulose nanomaterials' potential, we suggest cellulose nanomaterials have great untapped potential in water treatment technologies. In this review, we gather evidence of cellulose nanomaterials' beneficial role in environmental remediation and membranes for water filtration, including their high surface area-to-volume ratio, low environmental impact, high strength, functionalizability, and sustainability. We make direct comparison between cellulose nanomaterials and carbon nanotubes (CNTs) in terms of physical and chemical properties, production costs, use and disposal in order to show the potential of cellulose nanomaterials as a sustainable replacement for CNTs in water treatment technologies. Finally, we comment on the need for improved communication and collaboration across the myriad industries invested in cellulose nanomaterials production and development to achieve an efficient means to commercialization. PMID:25837659

  19. Polymorphy in native cellulose: recent developments

    International Nuclear Information System (INIS)

    In a number of earlier studies, the authors developed a model of cellulose structure based on the existence of two stable, linearly ordered conformations of the cellulose chain that are dominant in celluloses I and II, respectively. The model rests on extensive Raman spectral observations together with conformational considerations and solid-state 13C-NMR studies. More recently, they have proposed, on the basis of high resolution solid-state 13C-NMR observations, that native celluloses are composites of two distinct crystalline forms that coexist in different proportions in all native celluloses. In the present work, they examine the Raman spectra of the native celluloses, and reconcile their view of conformational differences with the new level of crystalline polymorphy of native celluloses revealed in the solid-state 13C-NMR investigations

  20. Field Errors in Hybrid Insertion Devices

    OpenAIRE

    Schlueter, R.D.

    1995-01-01

    Hybrid magnet theory as applied to the error analyses used in the design of Advanced Light Source (ALS) insertion devices is reviewed. Sources of field errors in hybrid insertion devices are discussed.

  1. Field errors in hybrid insertion devices

    Energy Technology Data Exchange (ETDEWEB)

    Schlueter, R.D. [Lawrence Berkeley Lab., CA (United States)

    1995-02-01

    Hybrid magnet theory as applied to the error analyses used in the design of Advanced Light Source (ALS) insertion devices is reviewed. Sources of field errors in hybrid insertion devices are discussed.

  2. Direct-puncture approach to the extraconal portion of the superior ophthalmic vein for carotid cavernous fistulae

    Energy Technology Data Exchange (ETDEWEB)

    Kurata, A.; Suzuki, S.; Iwamoto, K.; Miyazaki, T.; Inukai, M.; Abe, K.; Niki, J.; Yamada, M.; Fujii, K. [Kitasato University School of Medicine, Department of Neurosurgery, Kanagawa (Japan); Kan, S. [Kitasato University School of Medicine, Department of Radiology, Kanagawa (Japan)

    2009-11-15

    The transvenous approach via the superior ophthalmic vein (SOV) is an available approach for carotid cavernous fistula (CCF), especially in the event that there is no other suitable approach route to the fistula. Surgical exposure of the peripheral roots of the SOV is commonly used; however, often, the SOV is often not accessible because of anatomical problems and/or complications. In this paper, we present and discuss our original direct-puncture approach to the extraconal portion of the SOV. An attempt on three patients with traumatic CCF failed with the transarterial approach and the conventional venous approach via the inferior petrosal sinus; therefore, the patients were treated with the direct-puncture approach to the extraconal portion of the SOV using two-dimensional digital subtraction angiography with local anesthesia. All cases that had tortuous and partially stenotic division of the SOV were treated successfully with this approach and without complications. This approach will become an alternate approach, especially when the peripheral roots of the SOV are focally narrowed and tortuous, making it impossible to insert a catheter. (orig.)

  3. Direct-puncture approach to the extraconal portion of the superior ophthalmic vein for carotid cavernous fistulae

    International Nuclear Information System (INIS)

    The transvenous approach via the superior ophthalmic vein (SOV) is an available approach for carotid cavernous fistula (CCF), especially in the event that there is no other suitable approach route to the fistula. Surgical exposure of the peripheral roots of the SOV is commonly used; however, often, the SOV is often not accessible because of anatomical problems and/or complications. In this paper, we present and discuss our original direct-puncture approach to the extraconal portion of the SOV. An attempt on three patients with traumatic CCF failed with the transarterial approach and the conventional venous approach via the inferior petrosal sinus; therefore, the patients were treated with the direct-puncture approach to the extraconal portion of the SOV using two-dimensional digital subtraction angiography with local anesthesia. All cases that had tortuous and partially stenotic division of the SOV were treated successfully with this approach and without complications. This approach will become an alternate approach, especially when the peripheral roots of the SOV are focally narrowed and tortuous, making it impossible to insert a catheter. (orig.)

  4. Delayed bowel perforation following suprapubic catheter insertion

    OpenAIRE

    Mehta Ajay; Ahmed Shwan J; Rimington Peter

    2004-01-01

    Abstract Background Complications of suprapubic catheter insertion are rare but can be significant. We describe an unusual complication of a delayed bowel perforation following suprapubic catheter insertion. Case presentation A gentleman presented with features of peritonitis and feculent discharge along a suprapubic catheter two months after insertion of the catheter. Conclusion Bowel perforation is the most feared complication of suprapubic catheter insertion especially in patients with low...

  5. Does 'insertion' work? France's minimum income"

    OpenAIRE

    Whitton, Timothy

    1993-01-01

    International audience France's Revenu Minimum d Insertion (RMI) received the approval of the French Parliament on 1st December1988, and came into effect shortly afterwardsi. In addition to a means test, the RMI is conditional upon signature of a contract (le contrat d'insertion) by which its recipients pledge themselves to take whatever action the RMI authorities recommend in order to re-insert themselves in main-stream society. Insertion is a difficult concept to translate into English. ...

  6. Regional insertion: an emergent approach

    International Nuclear Information System (INIS)

    The Brazilian Electrical Sector incorporates new variables that expressing the extensive spectrum of environmental impacts in the take of decisions, referring to the viability of realizing a electrical undertaking, attends the several restrictions that are important by the sector and by the society in the environment area and promotes the adequate generation of liquid benefits, consequential of the electrical undertaking. Due to these factors, the Electrical Sector is improving the concept of regional insertion, with the sectorial expansion in long-dated and the created demand in the environmental and social area, focalizing the solution for these questions. (C.G.C.). 1 fig, 2 tabs

  7. Tetrahedral mesh for needle insertion

    OpenAIRE

    Syvertsen, Rolf Anders

    2007-01-01

    This is a Master’s thesis in how to make a tetrahedral mesh for use in a needle insertion simulator. It also describes how it is possible to make the simulator, and how to improve it to make it as realistic as possible. The medical simulator uses a haptic device, a haptic scene graph and a FEM for realistic soft tissue deformation and interaction. In this project a tetrahedral mesh is created from a polygon model, and then the mesh has been loaded into the HaptX haptic scene graph. The object...

  8. Color Doppler imaging of the ophthalmic artery in patients with chronic heart failure

    Directory of Open Access Journals (Sweden)

    Daniela B. Almeida-Freitas

    2011-10-01

    Full Text Available Purpose: To evaluate the ophthalmic artery hemodynamics in patients with chronic heart failure. Methods: Doppler parameters of ophthalmic artery of 18 patients with chronic heart failure in different stages of the disease were compared with 21 healthy volunteers (control group. These parameters were also correlated with echocardiographic assessments and clinical cardiologic status. Results: Mean diastolic velocity was 5.14 ± 2.4 cm/s in the chronic heart failure group and 7.44 ± 3.5 cm/s in the control group (p=0.007. Mean resistance index of the ophthalmic artery was 0.76 ± 0.08 in the chronic heart failure group and 0.70 ± 0.08 in the control group (p=0.04. Mean systolic velocity of the ophthalmic artery was 22.03 ± 7.7 cm/s in the chronic heart failure group and 25.32 ± 9.2 cm/s in the control group (p=0.24. There was a negative correlation between the resistance index of the ophthalmic artery and systemic blood pressure of patients with chronic heart failure (r= -0.47, p=0.007. Diastolic velocity of the ophthalmic artery correlated positively with systemic blood pressure (r=0.44, p=0.02. Conclusion: Lower diastolic velocity and higher resistance index were observed in the ophthalmic artery of chronic heart failure patients when compared to the control group, which probably reflects the presence of orbital vasoconstriction in response to low cardiac output. Therefore, the influence of these findings on the structure and function of the optic nerve head deserves investigation.

  9. Optimization of sup 125 I ophthalmic plaque brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Astrahan, M.A.; Luxton, G.; Jozsef, G.; Liggett, P.E.; Petrovich, Z. (Univ. of Southern California School of Medicine, Los Angeles (USA))

    1990-11-01

    Episcleral plaques containing {sup 125}I sources are often used in the treatment of ocular melanoma. Within four years post-treatment, however, the majority of patients experience some visual loss due to radiation retinopathy. The high incidence of late complications suggests that careful treatment optimization may lead to improved outcome. The goal of optimization would be to reduce the magnitude of vision-limiting complications without compromising tumor control. We have developed a three-dimensional computer model for ophthalmic plaque therapy which permits us to explore the potential of various optimization strategies. One simple strategy which shows promise is to maximize the ratio of dose to the tumor apex (T) compared to dose to the macula (M). By modifying the parameters of source location, activity distribution, source orientation, and shielding we find that the calculated T:M ratio can be varied by a factor of 2 for a common plaque design and posterior tumor location. Margins and dose to the tumor volume remain essentially unchanged.

  10. Design and construction of ophthalmic simulators for clinical applications

    International Nuclear Information System (INIS)

    This work presents a calculational methodology for dose determination in human eye structures, such as: sclera, choroid, retina, lens, vitreous body, optic nerve and disc, and cornea, as well as tumor due to treatment to the eye plaques. A human eye model was constructed taking into consideration its main structural and dimension characteristics. Beyond that a mathematical model for the Co-60 and 1-125 plaques with all geometric details were built employing the MCNP-4C code. This model is able to calculate the axial and radial doses in any point of the eye and for each of its structures. An acrylic eye simulator was also built with the aim to obtain experimental results for the both model validations. This simulator is made of an acrylic sphere split into foils of 1 mm thickness which allow the introduction of a radiographic film to measure the axial and radial doses. The experimental data were used to validate the MCNP-4C results. The data from the mathematical model will serve as the basis to build a data bank for all the eye structures allowing different position and sizes of tumor as well as the replacement of all ophthalmic plaques used in the treatment. This data bank will be the principal part for the construction of a national software for the dose calculation and can be of great help for a reliable treatment system planning in radiotherapy/brachytherapy. (author)

  11. Space Flight-Induced Intracranial Hypertension: An Ophthalmic Review

    Science.gov (United States)

    Gibson, Charles Robert; Mader, Thomas H.

    2010-01-01

    Background: Although physiologic and pathologic changes associated with microgravity exposure have been studied extensively, the effect of this environment on the eye is largely unknown. Over the last several years, NASA s Space Medicine Division has documented astronauts presenting with varying degrees of disc edema, globe flattening, choroidal folds, cotton wool spots, and hyperopic shifts after long-duration space flight. Methods: Before and after long-duration space flight, six astronauts underwent complete eye examinations to include cycloplegic and/or manifest refraction and fundus photography. Five of these astronauts had Optical Coherence Tomography (OCT) and Magnetic Resonance Imaging (MRI) performed following their missions. Results: Following exposure to space flight of approximately 6-months duration, six astronauts had neuro-ophthalmic findings. These consisted of disc edema in four astronauts, globe flattening in four astronauts, choroidal folds in four astronauts, cotton wool spots in three astronauts, nerve fiber layer thickening by OCT in five astronauts, and decreased near vision in five astronauts. Four of the astronauts with near vision complaints had a hyperopic shift equal to or greater than + 0.50D between pre- and post-mission spherical equivalent refraction in one or both eyes (range +0.50D to +1.50D). These same four had globe flattening by MRI. Conclusions: The findings we describe may have resulted from a rise in intracranial pressure caused by microgravity fluid shifts, and could represent parts of a spectrum of ocular and cerebral responses to extended microgravity.

  12. Calibration of ophthalmic applicators at NIST: A revised approach

    International Nuclear Information System (INIS)

    A revised approach to the problem of measuring a surface-absorbed dose from beta-particle-emitting ophthalmic applicators is presented. The technique chosen employs an extrapolation chamber equipped with a 4-mm-diam collecting electrode to make current measurements at air gaps from 0.08 to 0.20 mm at 0.02-mm intervals. These data yield a linear relationship between current and air gap, the slope of which is used to determine average surface-absorbed-dose rate over the central area of the source. For additional information about the distribution of the activity over the source surface, autoradiographs using calibrated radiochromic dye films are analyzed to map the dose-rate profile across the surface of the applicator. Experiments varying several parameters of the extrapolation chamber measurement, including collecting electrode area, voltage gradient, range of air gaps used, and entrance foil material, are described. Also treated are calibrations of, and a description of the use of, radiochromic dye films for source profiling. Experiments for determining correction factors for the extrapolation chamber measurements are described, and an assessment of the uncertainties associated with these measurements is given

  13. Surface modification of cellulose fibres

    Directory of Open Access Journals (Sweden)

    Mohamed Naceur Belgacem

    2005-06-01

    Full Text Available Several approaches to the modification of cellulose fibres are described, namely: (i physical treatments such as corona or plasma treatments under different atmospheres; (ii grafting with hydrophobic molecules using well-known sizing compounds; (iii grafting with bi-functional molecules, leaving one of the functions available for further exploitation; and (iv grafting with organometallic compounds. The modified surfaces were characterized by elemental analysis, contact angle measurements, inverse gas chromatography, X-ray photoelectron and infrared spectroscopy, wettability, etc. These different tools provided clear-cut evidence of the occurrence of chemical reactions between the grafting agent used and the hydroxy functions of the cellulose surface, as well as of the existence of covalent bonding in the ensuing composite materials between the matrix and the fibres through the use of doubly reactive coupling agents.

  14. Cellulose degradation by oxidative enzymes

    Directory of Open Access Journals (Sweden)

    Maria Dimarogona

    2012-09-01

    Full Text Available Enzymatic degradation of plant biomass has attracted intensive research interest for the production of economically viable biofuels. Here we present an overview of the recent findings on biocatalysts implicated in the oxidative cleavage of cellulose, including polysaccharide monooxygenases (PMOs or LPMOs which stands for lytic PMOs, cellobiose dehydrogenases (CDHs and members of carbohydrate-binding module family 33 (CBM33. PMOs, a novel class of enzymes previously termed GH61s, boost the efficiency of common cellulases resulting in increased hydrolysis yields while lowering the protein loading needed. They act on the crystalline part of cellulose by generating oxidized and non-oxidized chain ends. An external electron donor is required for boosting the activity of PMOs. We discuss recent findings concerning their mechanism of action and identify issues and questions to be addressed in the future.

  15. Formulation development and evaluation of long acti ng ophthalmic in-situ gelling system of Dorzolamide Hydrochloride

    Directory of Open Access Journals (Sweden)

    Apurva Laxmikant Deulker

    2013-12-01

    Full Text Available This research paper describes the objective of the present study to formulate ophthalmic mucoadhesive in situgelling system of Dorzolamide Hydrochloride using two different polymers namely Poly Acrylic Acid and Xanthan Gum, individually and in combinations. Cellulose (HPMC was used as viscosity enhancing agent. The developed formulations were subjected to several evaluation parameters includingphysico-chemical properties, compatibility, in-vitrodrug release, microbiological, ex-vivoand stability testing and compared with marketed formulation wherever possible. All formulations were found to be milky with pH between 6.0 to 6.5 for sols and nearly neutral for gels. All formulations showed instantaneous gelling with translucent gel matrix which retained its integrity for extended period of time. The viscosity of best formulation (F4 was found to be 20 cps. The drug was compatible with both the polymers and the viscoliserin both solid as well as liquid states. In-vitrodrug release studies showed that all the formulations released drug over a period of 12 hours with formulation F4 (0.2% w/v Xanthan Gum showing the highest drug release of 90.84% of Dorzolamide Hydrochloride. All the formulations showed zero order drug release with the release mechanism being diffusion along with erosion of gel matrix for all formulations. Further the drug release from all the formulation was observed to be non-fickian. The best batch showed ex-vivodrug release through goat’s cornea for 9 hours with the release kinetics being similar to those seen with in-vitrodrug release. All the formulations were found to be sterile.

  16. Internal clinical acceptance test of the dose rate of 106Ru/106Rh ophthalmic applicators

    International Nuclear Information System (INIS)

    For the last forty years or so, episcleral brachytherapy using 106Ru/106Rh ophthalmic applicators has been a proven method of therapy for uveal melanomas, sparing the globe and in many cases conserving the vision. In episcleral brachytherapy, a radioactive 106Ru/106Rh ophthalmic applicator (BEBIG Co., Berlin, Germany) is temporarily fixed on the surface of the bulbus oculi, whereby the intraocular tumour gets irradiated protractedly through the sclera. 106Ru/106Rh ophthalmic applicators are primarily beta sources, i.e. they generate a local dose escalation both in the vessels supplying the tumour and in the tumour itself, while simultaneously sparing the risk structures. In its certificates, BEBIG, the manufacturer of the product, indicates a dose rate for the 106Ru/106Rh ophthalmic applicators at a dose specification reference point which ensures traceability to the NIST standard (12/2001). The dose specification reference point is situated at a distance of 2 mm from the middle of the inner (concave) surface of the applicators, and the dose rate was measured with a scintillation detector (diameter 1 mm, height 0.5 mm). The manufacturer indicates for this dose rate at the dose specification reference point a relative measurement uncertainty of ±20% within the 95% confidence interval. Since the introduction of the NIST calibration, the quality of the calibration passed on by BEBIG to the user has been examined for n=45 ophthalmic applicators

  17. Use of phase-contrast magnetic resonance angiography to measure blood flow in the ophthalmic artery

    International Nuclear Information System (INIS)

    The aim of this study was to examine the usefulness of phase-contrast magnetic resonance (MR) angiography (PC-MRA) to measure blood flow in the ophthalmic artery. PC-MRA was performed in 16 volunteers with no ophthalmic abnormalities and measurement of blood flow based on the results was attempted. It was possible to measure blood flow in the ophthalmic artery using PC-MRA in all 16 volunteers. The mean (±1 standard deviation) velocity was 9.17±2.28 cm/second, peak systolic velocity was 16.69±3.33 cm/second, and end diastolic velocity was 3.69±2.44 cm/second. The resistivity index was 0.79±0.12, the pulsatility index was 1.49±0.41, and flow was 6.25±2.33 ml/minute. It was possible to identify the ophthalmic artery and a portion of the artery in which blood flow could be measured using MR imaging, a preliminary step to blood flow measurement using MR angiography. In addition to the velocity of blood flow in the ophthalmic artery, measurement of the amount of flow was possible with PC-MRA, which is one advantage of this method. (author)

  18. Cell adhesion on cellulose nanofibrils

    OpenAIRE

    Liljeström, Anna

    2016-01-01

    Cellulose nanofibrils (CNF) is an emerging biomaterial suitable for medical research. CNF hydrogel has been used as a three dimensional platforms for cell culture. This thesis aims to understand how human liver carcinoma (HepG2) cells interact with CNF. Measurements were performed with Quartz crystal microbalance with dissipation in order to quantify cell adsorption on CNF. Furthermore, the effect of the cell medium on the viscoelastic properties of CNF and on cell-CNF interactions were ...

  19. Lowering costs of microbial cellulose

    OpenAIRE

    Pajuelo, María González; Bungay, Henry; Hogg, Tim; Vasconcelos, Isabel

    1997-01-01

    We have been conducting research with Acetobacter xylinium for microbial conversion of sugars to cellulose. A rotating disk biological contactor should lower costs considerably because its production rates are greater than for the usual method of surface culture. Another major cost saving comes from replacing expensive sugars in the medium with sugars derived from wastes. Extracts of spent grapes from wastes of Portuguese wine factories supply suitable sugars for good production of micr...

  20. The Cellulase KORRIGAN Is Part of the Cellulose Synthase Complex

    NARCIS (Netherlands)

    Vain, T.; Crowell, E.F.; Timpano, H.; Biot, E.; Desprez, T.; Mansoori Zangir, N.; Trindade, L.M.; Pagant, S.; Robert, S.; Hofte, H.; Gonneau, M.; Vernhettes, S.

    2014-01-01

    Plant growth and organ formation depend on the oriented deposition of load-bearing cellulose microfibrils in the cell wall. Cellulose is synthesized by a large relative molecular weight cellulose synthase complex (CSC), which comprises at least three distinct cellulose synthases. Cellulose synthesis

  1. Cellulose-binding domains: tools for innovation in cellulosic fibre production and modification

    NARCIS (Netherlands)

    Quentin, M.G.E.; Valk, van der H.C.P.M.; Dam, van J.E.G.; Jong, de E.

    2003-01-01

    Plant cell walls are composed of cellulose, nature's most abundant macromolecule, and therefore represent a renewable resource of special technical importance. Cellulose degrading enzymes involved in plant cell wall loosening (expansins), or produced by plant pathogenic microorganisms (cellulases),

  2. Engineering of a novel cellulose-adherent cellulolytic Saccharomyces cerevisiae for cellulosic biofuel production.

    Science.gov (United States)

    Liu, Zhuo; Ho, Shih-Hsin; Sasaki, Kengo; den Haan, Riaan; Inokuma, Kentaro; Ogino, Chiaki; van Zyl, Willem H; Hasunuma, Tomohisa; Kondo, Akihiko

    2016-01-01

    Cellulosic biofuel is the subject of increasing attention. The main obstacle toward its economic feasibility is the recalcitrance of lignocellulose requiring large amount of enzyme to break. Several engineered yeast strains have been developed with cellulolytic activities to reduce the need for enzyme addition, but exhibiting limited effect. Here, we report the successful engineering of a cellulose-adherent Saccharomyces cerevisiae displaying four different synergistic cellulases on the cell surface. The cellulase-displaying yeast strain exhibited clear cell-to-cellulose adhesion and a "tearing" cellulose degradation pattern; the adhesion ability correlated with enhanced surface area and roughness of the target cellulose fibers, resulting in higher hydrolysis efficiency. The engineered yeast directly produced ethanol from rice straw despite a more than 40% decrease in the required enzyme dosage for high-density fermentation. Thus, improved cell-to-cellulose interactions provided a novel strategy for increasing cellulose hydrolysis, suggesting a mechanism for promoting the feasibility of cellulosic biofuel production. PMID:27079382

  3. Effects of reaction conditions on cellulose structures synthesized in vitro by bacterial cellulose synthases.

    Science.gov (United States)

    Penttilä, Paavo A; Sugiyama, Junji; Imai, Tomoya

    2016-01-20

    Cellulose was synthesized by cellulose synthases extracted from the Komagataeibacter xylinus (formerly known as Gluconacetobacter xylinus). The effects of temperature and centrifugation of the reaction solution on the synthesis products were investigated. Cellulose with number-average degree of polymerization (DPn) roughly in the range 60-80 and cellulose II crystal structure was produced under all conditions. The amount of cellulose varied with temperature and centrifugation, and the centrifugation at 2000 × g also slightly reduced the DPn. Cellulose production was maximal around the temperature 35 °C and without centrifugation. At higher temperatures and during centrifugation at 2000 × g the proteins started to denature, causing differences also in the morphology of the cellulosic aggregates, as seen with electron microscopy. These observations serve as a basis for discussions about the factors affecting the structure formation and chain length of in vitro synthesized cellulose. PMID:26572398

  4. Micromechanics and poroelasticity of hydrated cellulose networks.

    Science.gov (United States)

    Lopez-Sanchez, P; Rincon, Mauricio; Wang, D; Brulhart, S; Stokes, J R; Gidley, M J

    2014-06-01

    The micromechanics of cellulose hydrogels have been investigated using a new rheological experimental approach, combined with simulation using a poroelastic constitutive model. A series of mechanical compression steps at different strain rates were performed as a function of cellulose hydrogel thickness, combined with small amplitude oscillatory shear after each step to monitor the viscoelasticity of the sample. During compression, bacterial cellulose hydrogels behaved as anisotropic materials with near zero Poisson's ratio. The micromechanics of the hydrogels altered with each compression as water was squeezed out of the structure, and microstructural changes were strain rate-dependent, with increased densification of the cellulose network and increased cellulose fiber aggregation observed for slower compressive strain rates. A transversely isotropic poroelastic model was used to explain the observed micromechanical behavior, showing that the mechanical properties of cellulose networks in aqueous environments are mainly controlled by the rate of water movement within the structure. PMID:24784575

  5. Cellulose Synthases and Synthesis in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Anne Endler; Staffan Persson

    2011-01-01

    Plant cell walls are complex structures composed of high-molecular-weight polysaccharides,proteins,and lignins. Among the wall polysaccharides,cellulose,a hydrogen-bonded β-1,4-linked glucan microfibril,is the main load-bearing wall component and a key precursor for industrial applications. Cellulose is synthesized by large multi-meric cellulose synthase (CesA) complexes,tracking along cortical microtubules at the plasma membrane. The only known components of these complexes are the cellulose synthase proteins. Recent studies have identified tentative interaction partners for the CesAs and shown that the migratory patterns of the CesA complexes depend on phosphorylation status. These advances may become good platforms for expanding our knowledge about cellulose synthesis in the near future. In addition,our current understanding of cellulose chain polymerization in the context of the CesA complex is discussed.

  6. CELLULOSE POWDER FROM OLIVE INDUSTRY SOLID WASTE

    Directory of Open Access Journals (Sweden)

    Othman A. Hamed,

    2012-07-01

    Full Text Available In the present work, a method for extracting cellulose from olive industry solid waste has been developed. The method involves subjecting solid olive waste to kraft pulping, followed by multistep bleaching processes. The totally free chlorine chemical bleaching sequence APEP was the most effective and gave an average cellulose yield of about 35%. The extracted cellulose was extensively characterized using FTIR, EMS, HPLC, and viscometry. Our key finding in this study is that the extracted cellulose was found to have physio-chemical properties that are similar to those of conventional microcrystalline cellulose (MCC. This is important, as our results show how lignocellulosic agricultural wastes can be utilized to produce high value cellulose powder.

  7. Size Effects of Nano-crystalline Cellulose

    Institute of Scientific and Technical Information of China (English)

    Guo Kang LI; Xiao Fang LI; Yong JIANG; Mei Zhen ZENG; En Yong DING

    2003-01-01

    Natural cellulose with the crystal form of cellulose Ⅰ, when treated with condensed lye(e.g. 18%NaOH), can change into new crystal form of cellulose Ⅱ. But the nano-crystallinecellulose(NCC) can do it when only treated with dilute lye (e.g. 1%NaOH) at room temperatureand even can dissolve into slightly concentrated lye (e.g. 4%NaOH).

  8. Bulk and interfacial properties of cellulose ethers

    OpenAIRE

    Bodvik, Rasmus

    2012-01-01

    This work summarizes several studies that all concern cellulose ethers of the types methylcellulose (MC) hydroxypropylmethylcellulose (HPMC) and ethyl(hydroxyethyl)cellulose (EHEC). They share the feature of negative temperature response, as they are soluble in water at room temperature but phase separate and sometimes form gels at high temperatures. The different types of viscosity transitions occurring in these three cellulose ethers are well-known. However, earlier studies have not solved ...

  9. Drag Reduction of Bacterial Cellulose Suspensions

    OpenAIRE

    Ogata, Satoshi; Numakawa, Tetsuya; Kubo, Takuya

    2010-01-01

    Drag reduction due to bacterial cellulose suspensions with small environmental loading was investigated. Experiments were carried out by measuring the pressure drop in pipe flow. It was found that bacterial cellulose suspensions give rise to drag reduction in the turbulent flow range. We observed a maximum drag reduction ratio of 11% and found that it increased with the concentration of the bacterial cellulose suspension. However, the drag reduction effect decreased in the presence of mechani...

  10. Drag Reduction of Bacterial Cellulose Suspensions

    OpenAIRE

    Satoshi Ogata; Tetsuya Numakawa; Takuya Kubo

    2011-01-01

    Drag reduction due to bacterial cellulose suspensions with small environmental loading was investigated. Experiments were carried out by measuring the pressure drop in pipe flow. It was found that bacterial cellulose suspensions give rise to drag reduction in the turbulent flow range. We observed a maximum drag reduction ratio of 11% and found that it increased with the concentration of the bacterial cellulose suspension. However, the drag reduction effect decreased in the presence of mechani...

  11. Cellulose biosynthesis and function in bacteria.

    OpenAIRE

    Ross, P; Mayer, R; Benziman, M

    1991-01-01

    The current model of cellulose biogenesis in plants, as well as bacteria, holds that the membranous cellulose synthase complex polymerizes glucose moieties from UDP-Glc into beta-1,4-glucan chains which give rise to rigid crystalline fibrils upon extrusion at the outer surface of the cell. The distinct arrangement and degree of association of the polymerizing enzyme units presumably govern extracellular chain assembly in addition to the pattern and width of cellulose fibril deposition. Most e...

  12. Liquid crystalline cellulose derivatives for mirrorless lasing

    OpenAIRE

    Wenzlik, Daniel

    2013-01-01

    In this thesis cholesteric films made of liquid crystalline cellulose derivatives with improved optical properties were prepared. The choice of the solvent, hydrogen bond influencing additives, the synthetic realization of a very high degree of substitution on the cellulosic polymer and the use of mechanical stirring at the upper concentration limit of the liquid crystalline range were the basis for an improved alignment of the applied cellulose tricarbamates. In combination with a tuned subs...

  13. Lyocell, The New Generation of Regenerated Cellulose

    OpenAIRE

    Éva Borbély

    2008-01-01

    For the majority of the last century, commercial routes to regenerated cellulosefibres have coped with the difficulties of making a good cellulose solution by using an easyto dissolve derivative (e.g. xanthane in the case of viscose rayon) or complex (e.g.cuprammonium rayon). For the purposes of this paper, advanced cellulosic fibres aredefined as those made from a process involving direct dissolution of cellulose. The firstexamples of such fibres have now been generically designaed as lyocel...

  14. Alexa Fluor-labeled Fluorescent Cellulose Nanocrystals for Bioimaging Solid Cellulose in Spatially Structured Microenvironments

    Energy Technology Data Exchange (ETDEWEB)

    Grate, Jay W.; Mo, Kai-For; Shin, Yongsoon; Vasdekis, Andreas; Warner, Marvin G.; Kelly, Ryan T.; Orr, Galya; Hu, Dehong; Dehoff, Karl J.; Brockman, Fred J.; Wilkins, Michael J.

    2015-03-18

    Cellulose nanocrystal materials have been labeled with modern Alexa Fluor dyes in a process that first links the dye to a cyanuric chloride molecule. Subsequent reaction with cellulose nanocrystals provides dyed solid microcrystalline cellulose material that can be used for bioimaging and suitable for deposition in films and spatially structured microenvironments. It is demonstrated with single molecular fluorescence microscopy that these films are subject to hydrolysis by cellulose enzymes.

  15. Alteration of in vivo cellulose ribbon assembly by carboxymethylcellulose and other cellulose derivatives

    OpenAIRE

    1982-01-01

    In vivo cellulose ribbon assembly by the Gram-negative bacterium Acetobacter xylinum can be altered by incubation in carboxymethylcellulose (CMC), a negatively charged water-soluble cellulose derivative, and also by incubation in a variety of neutral, water-soluble cellulose derivatives. In the presence of all of these substituted celluloses, normal fasciation of microfibril bundles to form the typical twisting ribbon is prevented. Alteration of ribbon assembly is most extensive in the presen...

  16. Comparative studies of various hyaluronic acids produced by microbial fermentation for potential topical ophthalmic applications

    DEFF Research Database (Denmark)

    Guillaumie, Fanny; Furrer, Pascal; Felt-Baeyens, Olivia;

    2010-01-01

    This work presents a comparative study of various hyaluronic acids (HA) produced by fermentation of either Bacillus subtilis or Streptococcus towards the selection of an optimal molecular weight (MW) HA for the preparation of topical ophthalmic formulations. The influence of HA MW on water binding...... capacity, sterile filtration, rheological properties, precorneal residence time and ocular tolerance of ophthalmic solutions was investigated. Molecular weight did not affect hydration of hyaluronic acid according to differential scanning calorimetry (DSC). In general, medium MW HA (0.6–1 MDa) resulted in...... ophthalmoscopy (CLSO) conclusively showed the excellent tolerance of both Bacillus-derived HA and Streptococcus-derived HA after topical instillation onto the corneal surface. Overall, this comprehensive work highlights the superiority of medium MW hyaluronic acid for topical ophthalmic formulations based on...

  17. Comparison of the effectiveness of contemporary ophthalmic lenses against β radiation

    International Nuclear Information System (INIS)

    As part of a study intended to identify the lens material and type that provides maximum eye protection against beta radiation, the effectiveness of contemporary ophthalmic lenses has been evaluated. From the calculations and measurements presented it is evident that safety glasses with crown glass ophthalmic lenses afford the eye the greatest protection against beta radiation, whereas street glasses with plastic ophthalmic lenses afford the eye very little protection. It is to be noted that glass street lenses (approximately 2.2 mm thick) provide greater protection than plastic safety lenses (approximately 3.5 mm thick). A warning is given against the use of safety lenses containing a large percentage of thorium. (U.K.)

  18. Spontaneous resolution of a flow-related ophthalmic-segment aneurysm after treatment of anterior cranial fossa dural arteriovenous fistula

    Directory of Open Access Journals (Sweden)

    Kevin Reinard

    2014-01-01

    Full Text Available Background: The natural history of proximal, feeding-artery aneurysms after successful obliteration of high-grade, anterior cranial fossa dural arteriovenous fistulas (dAVFs has not been well documented. Case Description: A 52-year-old Caucasian male presented with an unruptured anterior cranial fossa (dAVF and an associated aneurysm. Cerebral angiography revealed a large, contralateral, carotid-ophthalmic segment aneurysm, enlarged feeding ophthalmic arteries, as well as cortical venous drainage. Successful surgical obliteration of the dAVF was undertaken to eliminate the risk of hemorrhage. Conclusion: The carotid-ophthalmic aneurysm regressed significantly after surgical obliteration of the dAVF and a follow-up, planned coiling procedure to address the carotid-ophthalmic aneurysm was abandoned. This represents the first reported case of a near complete, spontaneous resolution of an unruptured carotid-ophthalmic aneurysm associated with a high-grade anterior cranial fossa dAVF.

  19. Cytocompatible cellulose hydrogels containing trace lignin.

    Science.gov (United States)

    Nakasone, Kazuki; Kobayashi, Takaomi

    2016-07-01

    Sugarcane bagasse was used as a cellulose resource to prepare transparent and flexible cellulose hydrogel films. On the purification process from bagasse to cellulose, the effect of lignin residues in the cellulose was examined for the properties and cytocompatibility of the resultant hydrogel films. The cellulose was dissolved in lithium chloride/N,N-dimethylacetamide solution and converted to hydrogel films by phase inversion. In the purification process, sodium hydroxide (NaOH) treatment time was changed from 1 to 12h. This resulted in cellulose hydrogel films having small amounts of lignin from 1.62 to 0.68%. The remaining lignin greatly affected hydrogel properties. Water content of the hydrogel films was increased from 1153 to 1525% with a decrease of lignin content. Moreover, lower lignin content caused weakening of tensile strength from 0.80 to 0.43N/mm(2) and elongation from 45.2 to 26.5%. Also, similar tendency was observed in viscoelastic behavior of the cellulose hydrogel films. Evidence was shown that the lignin residue was effective for the high strength of the hydrogel films. In addition, scanning probe microscopy in the morphological observation was suggested that the trace lignin in the cellulose hydrogel affected the cellulose fiber aggregation in the hydrogel network. The trace of lignin in the hydrogels also influenced fibroblast cell culture on the hydrogel films. The hydrogel film containing 1.68% lignin showed better fibroblast compatibility as compared to cell culture polystyrene dish used as reference. PMID:27127053

  20. Carboxymethylation of Cellulose by Microwave irradiation

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ Cellulose may be readily converted into ethers involving primary and secondary alcohol groups in each monomer unit and the glycosidic bonds. However, these reactions are rather more complicated than with simple substances, because the stereochemistry of the cellulose molecule is such that the vast majority of its hydroxyl groups form intra-chain hydrogen bonds or inter-chain hydrogen bonds with contiguous molecules. Carboxymethylcellulose (CMC) has played an important part in the commercial uses of cellulose derivatives. CMC becomes alkali and water soluble. The polarity can, in fact, be increased by introduction of ionizing groups, ie carboxymethyl group. CMC is generally produced by the reaction of alkali cellulose with chloroacetic acid.

  1. Chemo-catalytic valorization of cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Palkovits, R. [RWTH Aachen Univ. (Germany). Inst. fuer Technische und Makromolekulare Chemie

    2012-07-01

    Cellulose can be utilized as carbon source for the production of novel platform molecules as well as fuel motifs. Promising transformation strategies cover the hydrolytic hydrogenation or hydrogenolysis of cellulose to sugar alcohols, the hydrolysis of cellulose to glucose followed by dehydration to 5-hydroxymethylfurfural or levulinic acid and the further hydrogenation of levulinic acid to {gamma}-valerolactone. Main challenges result from the high degree of functionalization of cellulosic feedstocks. In line, processes are carried out in liquid phase utilizing rather polar solvents and aiming for a tailored defunctionalisation of these oxygen rich compounds. Consequently, such transformations require novel strategies concerning the development of suitable catalysts and appropriate process concepts. (orig.)

  2. Simultaneous cellulose conversion and hydrogen production assisted by cellulose decomposition under UV-light photocatalysis

    OpenAIRE

    Zhang, Guan; Ni, Chengsheng; Huang, Xiubing; Welgamage, Aakash; Lawton, Linda A.; Robertson, Peter K. J.; Irvine, John T. S.

    2016-01-01

    Photocatalytic conversion of cellulose to sugars and carbon dioxide with simultaneous production of hydrogen assisted by cellulose decomposition under UV or solar light irradiation was achieved upon immobilization of cellulose onto a TiO2 photocatalyst. This approach enables production of hydrogen from water without using valuable sacrificial agents, and provides the possibility for recovering sugars as liquid fuels.

  3. Simultaneous cellulose conversion and hydrogen production assisted by cellulose decomposition under UV-light photocatalysis.

    Science.gov (United States)

    Zhang, Guan; Ni, Chengsheng; Huang, Xiubing; Welgamage, Aakash; Lawton, Linda A; Robertson, Peter K J; Irvine, John T S

    2016-01-28

    Photocatalytic conversion of cellulose to sugars and carbon dioxide with simultaneous production of hydrogen assisted by cellulose decomposition under UV or solar light irradiation was achieved upon immobilization of cellulose onto a TiO2 photocatalyst. This approach enables production of hydrogen from water without using valuable sacrificial agents, and provides the possibility for recovering sugars as liquid fuels. PMID:26661296

  4. High Performance Regenerated Cellulose Membranes from Trimethylsilyl Cellulose

    KAUST Repository

    Ali, Ola

    2013-05-01

    Regenerated cellulose (RC) membranes are extensively used in medical and pharmaceutical separation processes due to their biocompatibility, low fouling tendency and solvent resistant properties. They typically possess ultrafiltration and microfiltration separation characteristics, but recently, there have been attempts to widen their pool of applications in nanofiltration processes. In this work, a novel method for preparing high performance composite RC membranes was developed. These membranes reveal molecular weight cut-offs (MWCO) of less than 250 daltons, which possibly put them ahead of all commercial RC membranes and in competition with high performance nanofiltration membranes. The membranes were prepared by acidic hydrolysis of dip-coated trimethylsilyl cellulose (TMSC) films. TMSC, with a degree of silylation (DS) of 2.8, was prepared from microcrystalline cellulose by reaction with hexamethyldisilazane under the homogeneous conditions of LiCl/DMAC solvent system. Effects of parameters, such as coating solution concentration and drying rates, were investigated. It was concluded that higher TMSC concentrations as well as higher solvent evaporation rates favor better MWCOs, mainly due to increase in the selective layer thickness. Successful cross-linking of prepared membranes with glyoxal solutions, in the presence of boric acid as a catalyst, resulted in MWCOs less than 250 daltons. The suitability of this crosslinking reaction for large scale productions was already proven in the manufacturing of durable-press fabrics. For us, the inexpensive raw materials as well as the low reaction times and temperatures were of interest. Moreover, the non-toxic nature of glyoxal is a key advantage in medical and pharmaceutical applications. The membranes prepared in this work are strong candidates for separation of small organic solutes from organic solvents streams in pharmaceutical industries. Their hydrophilicity, compared to typical nanofiltration membranes, offer

  5. Dosimetric Benefit of a New Ophthalmic Radiation Plaque

    Energy Technology Data Exchange (ETDEWEB)

    Marwaha, Gaurav, E-mail: marwahg2@ccf.org [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic Foundation, Cleveland, Ohio (United States); Cleveland Clinic Foundation, Cleveland, Ohio (United States); Wilkinson, Allan [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic Foundation, Cleveland, Ohio (United States); Cleveland Clinic Foundation, Cleveland, Ohio (United States); Bena, James [Department of Quantitative Health Sciences, Cleveland Clinic Foundation, Cleveland, Ohio (United States); Cleveland Clinic Foundation, Cleveland, Ohio (United States); Macklis, Roger [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic Foundation, Cleveland, Ohio (United States); Cleveland Clinic Foundation, Cleveland, Ohio (United States); Singh, Arun D. [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic Foundation, Cleveland, Ohio (United States); Department of Ophthalmic Oncology, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, Ohio (United States); Cleveland Clinic Foundation, Cleveland, Ohio (United States)

    2012-12-01

    Purpose: To determine whether the computed dosimetry of a new ophthalmic plaque, EP917, when compared with the standard Collaborative Ocular Melanoma Study (COMS) plaques, could reduce radiation exposure to vision critical structures of the eye. Methods and Materials: One hundred consecutive patients with uveal melanoma treated with COMS radiation plaques between 2007 and 2010 were included in this study. These treatment plans were generated with the use of Bebig Plaque Simulator treatment-planning software, both for COMS plaques and for EP917 plaques using I-125. Dose distributions were calculated for a prescription of 85 Gy to the tumor apex. Doses to the optic disc, opposite retina, lens, and macula were obtained, and differences between the 2 groups were analyzed by standard parametric methods. Results: When compared with the COMS plaques, the EP917 plaques used fewer radiation seeds by an average difference of 1.94 (P<.001; 95% confidence interval [CI], -2.8 to -1.06) and required less total strength of radiation sources by an average of 17.74 U (air kerma units) (P<.001; 95% CI, -20.16 to -15.32). The total radiation doses delivered to the optic disc, opposite retina, and macula were significantly less by 4.57 Gy, 0.50 Gy, and 11.18 Gy, respectively, with the EP917 plaques vs the COMS plaques. Conclusion: EP917 plaques deliver less overall radiation exposure to critical vision structures than COMS treatment plaques while still delivering the same total therapeutic dose to the tumor.

  6. Topotecan Delivery to the Optic Nerve after Ophthalmic Artery Chemosurgery

    Science.gov (United States)

    Taich, Paula; Requejo, Flavio; Asprea, Marcelo; Sgroi, Mariana; Gobin, Pierre; Abramson, David H.; Chantada, Guillermo; Schaiquevich, Paula

    2016-01-01

    Extraocular retinoblastoma is a major challenge worldwide, especially in developing countries. Current treatment involves the administration of systemic chemotherapy combined with radiation, but there is a clear need for improvement of chemotherapy bioavailability in the optic nerve. Our aim was to study the ophthalmic artery chemosurgery (OAC) local route for drug delivery assessing ocular and optic nerve exposure to chemotherapy and to compare it to exposure after intravenous infusion (IV) of the same dose in an animal model. Topotecan was used as a prototype drug that is active in retinoblastoma and based on the extensive knowledge of its pharmacokinetics in preclinical and clinical settings. Five Landrace pigs received 4mg of topotecan via OAC as performed in retinoblastoma patients. At the end of the infusion, the eyes were enucleated, the optic nerve and retina were dissected, and the vitreous and plasma were separated. After recovery and a wash-out period, the animals received a 30-min IV infusion of topotecan (4 mg). The remaining eye was enucleated and tissues and fluids were separated. All samples were stored until quantitation using HPLC. A significantly higher concentration of topotecan in the optic nerve, vitreous, and retina was obtained in eyes after OAC compared to IV infusion (p0.05). The median optic nerve-to-plasma ratio after OAC and IV was 44 and 0.35, respectively. Topotecan OAC delivery attained an 80-fold higher concentration in the optic nerve compared to the systemic infusion of the same dose with similar plasma concentrations in a swine model. Patients with retinoblastoma extension into the optic nerve may benefit from OAC for tumor burden by increased chemotherapy bioavailability in the optic nerve without increasing systemic exposure or toxicity. PMID:26959658

  7. Dose distribution determination of ruthenium-106 ophthalmic applicators

    International Nuclear Information System (INIS)

    Full text: Dose distributions of COB and CCA type ruthenium-106 ophthalmic applicators (15 and 20 mm diameter) were investigated using small thin CaSO4:Dy thermoluminescent dosimeters with dimensions of approximately 2 x 3 x 0.05 mm3. TLD characteristics, namely linearity, reproducibility and sensitivity were studied. Measured sensitivities (variations in response to a nominal dose due to differences in size, homogeneity, etc) of individual TLD discs ranged from approximately -20% to +17%. TLDs were then placed at different positions in a water equivalent eye phantom. Dose points in planes at 1 to 10 mm depths from the plaque active surface were measured. Hot spots and cold spots (up to 50% difference from the dose on the central axis) were found in various positions throughout the plaques. The depth dose values provided by the manufacturer agreed well with the measured ones, but the standard errors for TLD measurements were considerably less than that of manufacturer. The percentage uncertainty obtained with proposed method was on average better than 5% compared to 30% indicated by manufacturer. MOSFET semiconductor detector was also employed in determination of Percentage Depth Dose (PDD) of the plaques. This was found to be a very feasible dosimetry method providing fast readout and high sensitivity to low radiation doses. The measurements agreed within a few percent with TLD results and manufacturer provided data. Determination of dose distributions of ruthenium-106 applicators using small CaSO4:Dy TLDs proved to be a useful technique for estimation of 2D dose distributions resulting from plaque treatments. On the other hand, fast measurement of PDD using MOSFET detector can be used for regular quality assurance and acceptance testing of the plaques

  8. An interactive treatment planning system for ophthalmic plaque radiotherapy

    International Nuclear Information System (INIS)

    Brachytherapy using removable episcleral plaques containing sealed radioisotope sources is being studied as an alternative to enucleation in the treatment of choroidal melanoma and other tumors of the eye. Encouraging early results have been reported, but late complications which lead to loss of vision continue to be a problem. A randomized national study, the Collaborative Ocular Melanoma Study (COMS) is currently in progress to evaluate the procedure. The COMS specified isotope is 125I. Precise dosimetric calculations near the plaque may correlate strongly with complications and could also be used to optimize isotope loading patterns in the plaques. A microcomputer based treatment planning system has been developed for ophthalmic plaque brachytherapy. The program incorporates an interactive, 3-dimensional, solid-surface, color-graphic interface. The program currently supports 125I and 192Ir seeds which are treated as anisotropic line sources. Collimation effects related to plaque structure are accounted for, permitting detailed study of shielding effectiveness near the lip of a plaque. A dose distribution matrix may be calculated in any subregion of a transverse, sagittal, or coronal planar cross section of the eye, in any plane transecting the plaque and crossing the eye diametrically, or on a spherical surface within or surrounding the eye. Spherical surfaces may be displayed as 3-dimensional perspective projections or as funduscopic diagrams. Isodose contours are interpolated from the dose matrix. A pointer is also available to explicitly calculate and display dose at any location on the dosimetry surface. An interactive editing capability allows new plaque designs to be rapidly added to the system

  9. Investigation of the imaging diagnosis on the ophthalmic orbital diseases

    International Nuclear Information System (INIS)

    Ultrasonographic examination, X-ray computerized tomography (CT) and magnetic resonance imaging (MRI) were performed on orbital diseases. Ultrasonographic examination was a simple, rapid and harmless noninvasive precedure as a diagnostic tool for evaluation of soft tissues. Echography was not more precise than X-ray CT and MRI scan in orbital diagnosis of the localization, size and well-defined outline of the lesion, relating to the peri- and retroorbital organs, however, was useful for screening study of an orbital lesion. B-mode of orbital tumors was effective for the ultrasonic diagnosis and classification according to four types; solid, cystic, angiomatous and infiltrative patterns. B-scan study of intraorbital inflammatory pseudo tumor could provide a differential diagnosis between inflammatory edema and an inflammatory mass lesion. Echographic pictures of dural arterio-venous fistula disclosed the vascular dilatation of superior ophthalmic vein and those of Basedow's disease with thickening of extraocular muscles. X-ray CT revealed intraorbital and intraocular disease, the globes and its immediate surrounding tissue (optic nerve, extraocular muscle, etc.) and bony orbital walls as the same slice of film. X-ray CT pictures of a coronal section, the contrast enhancement, calcification and destruction of the bone were helpful for diagnosis. However, the displays of disorders near the bone were ill-defined because of an artifact induced by high X-ray absorptive power of the bone. MRI was an equipment for superior contrast resolution, with provided a tomography of any section, without artifacts of the bone, and was the superior technique for displaying a vascular lesion. MRI of orbital disease was effective for reconstructing the spatial correlations between the lesion and its surounding tissues. MRI, however, provided no information of the skeleton, being not available for subjects with a magnetic substance. (author)

  10. Dosimetric Benefit of a New Ophthalmic Radiation Plaque

    International Nuclear Information System (INIS)

    Purpose: To determine whether the computed dosimetry of a new ophthalmic plaque, EP917, when compared with the standard Collaborative Ocular Melanoma Study (COMS) plaques, could reduce radiation exposure to vision critical structures of the eye. Methods and Materials: One hundred consecutive patients with uveal melanoma treated with COMS radiation plaques between 2007 and 2010 were included in this study. These treatment plans were generated with the use of Bebig Plaque Simulator treatment-planning software, both for COMS plaques and for EP917 plaques using I-125. Dose distributions were calculated for a prescription of 85 Gy to the tumor apex. Doses to the optic disc, opposite retina, lens, and macula were obtained, and differences between the 2 groups were analyzed by standard parametric methods. Results: When compared with the COMS plaques, the EP917 plaques used fewer radiation seeds by an average difference of 1.94 (P<.001; 95% confidence interval [CI], −2.8 to −1.06) and required less total strength of radiation sources by an average of 17.74 U (air kerma units) (P<.001; 95% CI, −20.16 to −15.32). The total radiation doses delivered to the optic disc, opposite retina, and macula were significantly less by 4.57 Gy, 0.50 Gy, and 11.18 Gy, respectively, with the EP917 plaques vs the COMS plaques. Conclusion: EP917 plaques deliver less overall radiation exposure to critical vision structures than COMS treatment plaques while still delivering the same total therapeutic dose to the tumor.

  11. Persistent corneal epithelial defect responding to rebamipide ophthalmic solution in a patient with diabetes

    Directory of Open Access Journals (Sweden)

    Hayashi Y

    2016-05-01

    Full Text Available Yusuke Hayashi, Hiroshi Toshida, Yusuke Matsuzaki, Asaki Matsui, Toshihiko Ohta Department of Ophthalmology, Juntendo University Shizuoka Hospital, Izunokuni, Shizuoka, Japan Objective: Rebamipide ophthalmic suspension was developed for the treatment of dry eyes and for other corneal diseases, promoting the secretion of both mucin in tear fluid and membrane-associated mucin, increasing the number of goblet cells, and restoring the barrier function of the corneal epithelium. We report a case of a persistent corneal epithelial defect in a patient with diabetes treated with topical application of rebamipide ophthalmic suspension. Case presentation: A 73-year-old woman had a history of type 2 diabetes for 35 years and nonproliferative diabetic retinopathy for 23 years. She presented to our department with discharge and ophthalmalgia in the left eye. A corneal ulcer was detected, and culture of corneal scrapings was performed, with Staphylococcus aureus and Streptococcus canis being isolated. The infection was treated with levofloxacin eye drops and ofloxacin ophthalmic ointment based on the sensitivity profile of the isolate. However, a corneal epithelial defect persisted for approximately 2 months despite continuing treatment with 0.1% hyaluronic acid ophthalmic suspension and 0.3% ofloxacin eye ointment. Her hemoglobin A1c was 7.3%. The persistent corneal epithelial defect showed improvement at 2 weeks after treatment with rebamipide unit dose 2% ophthalmic suspension, and it did not recur even when vitrectomy was subsequently performed for vitreous hemorrhage due to progression of diabetic retinopathy. Conclusion: This is the first report about efficacy of rebamipide unit dose 2% ophthalmic suspension for presenting persistent corneal epithelial defect in a patient with diabetes. In the present case, the suggested mechanisms are the following: improving the corneal barrier function, stabilization of mucin on the keratoconjunctival epithelium, and

  12. Persistent corneal epithelial defect responding to rebamipide ophthalmic solution in a patient with diabetes

    Science.gov (United States)

    Hayashi, Yusuke; Toshida, Hiroshi; Matsuzaki, Yusuke; Matsui, Asaki; Ohta, Toshihiko

    2016-01-01

    Objective Rebamipide ophthalmic suspension was developed for the treatment of dry eyes and for other corneal diseases, promoting the secretion of both mucin in tear fluid and membrane-associated mucin, increasing the number of goblet cells, and restoring the barrier function of the corneal epithelium. We report a case of a persistent corneal epithelial defect in a patient with diabetes treated with topical application of rebamipide ophthalmic suspension. Case presentation A 73-year-old woman had a history of type 2 diabetes for 35 years and nonproliferative diabetic retinopathy for 23 years. She presented to our department with discharge and ophthalmalgia in the left eye. A corneal ulcer was detected, and culture of corneal scrapings was performed, with Staphylococcus aureus and Streptococcus canis being isolated. The infection was treated with levofloxacin eye drops and ofloxacin ophthalmic ointment based on the sensitivity profile of the isolate. However, a corneal epithelial defect persisted for approximately 2 months despite continuing treatment with 0.1% hyaluronic acid ophthalmic suspension and 0.3% ofloxacin eye ointment. Her hemoglobin A1c was 7.3%. The persistent corneal epithelial defect showed improvement at 2 weeks after treatment with rebamipide unit dose 2% ophthalmic suspension, and it did not recur even when vitrectomy was subsequently performed for vitreous hemorrhage due to progression of diabetic retinopathy. Conclusion This is the first report about efficacy of rebamipide unit dose 2% ophthalmic suspension for presenting persistent corneal epithelial defect in a patient with diabetes. In the present case, the suggested mechanisms are the following: improving the corneal barrier function, stabilization of mucin on the keratoconjunctival epithelium, and improving the wettability and stability of the tear film, which resulted in the promotion of healing of the corneal epithelial defect in a short time period. PMID:27257394

  13. The Use of Ophthalmic Ultrasonography to Identify Retinal Injuries Associated With Abusive Head Trauma.

    Science.gov (United States)

    Riggs, Becky J; Trimboli-Heidler, Carmelina; Spaeder, Michael C; Miller, Marijean M; Dean, Nathan P; Cohen, Joanna S

    2016-05-01

    Abusive head trauma includes any nonaccidental injury inflicted to a child's head and body. It is often characterized by, but not limited to, the repetitive acceleration-deceleration forces with or without blunt head impact. It has a mortality rate of 30%, and 80% of survivors experience permanent neurologic damage. In this case series, we hypothesize that bedside ultrasonography can be useful in the identification of retinal injuries that are consistent with abusive head trauma. Ocular manifestations of abusive head trauma are identified by dilated ophthalmic examination showing retinal hemorrhages that are too numerous to count, multilayered, and extending to the periphery. Traumatic retinoschisis, splitting of the retinal layers with or without blood accumulating in the intervening space, is exclusive for abusive head trauma in infants without a history of significant cerebral crush injury. Direct visualization of intraocular structures is difficult when the eyelids are swollen shut or when dilatation must be delayed. We present a series of 11 patients with brain injuries who underwent ophthalmic point-of-care ultrasonography that revealed traumatic retinoschisis on average 60 hours earlier than direct ophthalmic visualization. Dilated ophthalmic examinations and autopsy reports confirmed retinoschisis and other forms of retinal hemorrhages that were too numerous to count, multilayered, and extending to the periphery in all 11 patients. One patient did not have a dilated ophthalmic examination; however, traumatic retinoschisis and retinal hemorrhages were confirmed on autopsy. Ocular point-of-care ultrasonography is a promising tool to investigate abusive head trauma through the identification of traumatic retinoschisis and retinal hemorrhages when pupillary dilatation and direct ophthalmic examination is delayed. PMID:26481265

  14. Generalized ray tracing method for the calculation of the peripheral refraction induced by an ophthalmic lens

    OpenAIRE

    Rojo Badenas, Pilar

    2015-01-01

    This thesis proposes a method to evaluate and quantify in a precise way the peripheral refraction induced by an ophthalmic lens. The motivation for this work stems from the progression of myopia and its possible causes; two of them are particularly key for this PhD: (a) Peripheral refraction of the eye may have an important role in the progression of myopia and (b) ophthalmic lenses are the compensating element more used in children and teenagers. These two elements fully justify the need for...

  15. Determination of drug concentration in aqueous humor of cataract patients administered gatifloxacin ophthalmic gel

    Institute of Scientific and Technical Information of China (English)

    LIU Xuan; WANG Ning-li; WANG Yan-ling; MA Chen; MA Li; GAO Li-xin; HUANG Ying-xiang; XIONG Shi-hong; WANG Kang

    2010-01-01

    Background Ophthalmic gel has been developed to increase the drug concentration in aqueous humor and to retard the loss of drug from the conjunctival sac.The research was to compare the drug concentration in aqueous humor of cataract patients administered 0.3% gatifloxacin ophthalmic gel with that in patients administered 0.3% gatifloxacin ophthalmic solution.Methods Ninety-six patients with cataract (96 eyes) were randomly assigned to 8 groups.The patients in groups 1-4received topical gatifloxacin 0.3% ophthalmic gel and those in groups 5-8 received gatifloxacin 0.3% ophthalmic solution.The dose regimen was 1 drop, 4 times a day for 3 consecutive days prior to cataract surgery.On the day of surgery, 1drop was applied at 15, 30, 60 or 120 minutes before commencement of cataract surgery in groups 1 and 5, groups 2 and 6, goups 3 and 7, and groups 4 and 8, respectively.Aqueous humor was extracted during the cataract surgery for the analysis of gatifloxacin concentration..Results The concentrations of gatifloxacin in aqueous humor were (0.24±0.25) μg/ml, (1.11±0.74) μg/ml, (2.32±2.01)μg/ml and (1.85±1.14) μg/ml in groups 1 to 4, and (0.16±0.25) μg/ml, (0.31±0.24) μg/ml, (0.75±0.28) μg/ml and (0.33±0.22) μg/ml in groups 5 to 8, respectively.Patients receiving gatifloxacin ophthalmic gel showed greater mean values of gatifloxacin concentration in aqueous humor than those receiving gatifloxacin solution, and such differences were significant with P <0.05 for all comparisons except that between groups 1 and 5.Conclusion Topical gatifloxacin ophthalmic gel can attain significantly greater drug concentrations in human aqueous humor than gatifloxacin ophthalmic solution.

  16. Color Doppler imaging of the ophthalmic artery in patients with chronic heart failure

    OpenAIRE

    Almeida-Freitas, Daniela B.; Daniel Meira-Freitas; Luiz Alberto Soares Melo Jr.; Augusto Paranhos Jr.; Wagner Iared; Sergio Ajzen

    2011-01-01

    Purpose: To evaluate the ophthalmic artery hemodynamics in patients with chronic heart failure. Methods: Doppler parameters of ophthalmic artery of 18 patients with chronic heart failure in different stages of the disease were compared with 21 healthy volunteers (control group). These parameters were also correlated with echocardiographic assessments and clinical cardiologic status. Results: Mean diastolic velocity was 5.14 ± 2.4 cm/s in the chronic heart failure group and 7.44 ± 3.5 cm/s in ...

  17. Endovascular treatment of large and giant ophthalmic aneurysms with preservation of parent artery

    International Nuclear Information System (INIS)

    Objective: To evaluate the endovascular embolization treatment of large and giant ophthalmic aneurysms. Methods: Three aneurysms were embolized with coils only and 5 aneurysms were treated with stent placement together with subsequent coiling. Results: In the 3 aneurysms treated only with GDC, total embolization was achieved in 1 and partial embolization in 2. In the stent placement and coiling case, 4 aneurysms were densely packed and another one was partially packed. Conclusions: Combined stenting and coiling is effective and safe for the treatment of large and giant ophthalmic artery aneurysm with the preservation of parent artery

  18. Ophthalmic applicators: An overview of calibrations following the change to SI units

    International Nuclear Information System (INIS)

    Since the NIST dose to water standard for 90Sr/90Y ophthalmic applicators was introduced, numerous sources have undergone calibration either at NIST or at the University of Wisconsin Accredited Dosimetry Calibration Laboratory (UWADCL). From 1997 to 2008, 222 of these beta-emitting sources were calibrated at the UWADCL, and prior reference source strength values were available for 149 of these sources. A survey of UWADCL ophthalmic applicator calibrations is presented here, demonstrating an average discrepancy of -19% with a standard deviation of ±16% between prior reference values and the NIST-traceable UWADCL absorbed dose to water calibrations. Values ranged from -49% to +42%.

  19. PanoInserts: mobile spatial teleconferencing

    OpenAIRE

    Pece, F.; Steptoe, W.; F. Wanner; Julier, S.; Weyrich, T.; Kautz, J.; Steed, A.

    2013-01-01

    We present PanoInserts: a novel teleconferencing system that uses smartphone cameras to create a surround representation of meeting places. We take a static panoramic image of a location into which we insert live videos from smartphones. We use a combination of marker- and image-based tracking to position the video inserts within the panorama, and transmit this representation to a remote viewer. We conduct a user study comparing our system with fully-panoramic video and conventional webcam vi...

  20. Pyrolytic sugars from cellulosic biomass

    Science.gov (United States)

    Kuzhiyil, Najeeb

    Sugars are the feedstocks for many promising advanced cellulosic biofuels. Traditional sugars derived from starch and sugar crops are limited in their availability. In principle, more plentiful supply of sugars can be obtained from depolymerization of cellulose, the most abundant form of biomass in the world. Breaking the glycosidic bonds between the pyranose rings in the cellulose chain to liberate glucose has usually been pursued by enzymatic hydrolysis although a purely thermal depolymerization route to sugars is also possible. Fast pyrolysis of pure cellulose yields primarily levoglucosan, an anhydrosugar that can be hydrolyzed to glucose. However, naturally occurring alkali and alkaline earth metals (AAEM) in biomass are strongly catalytic toward ring-breaking reactions that favor formation of light oxygenates over anhydrosugars. Removing the AAEM by washing was shown to be effective in increasing the yield of anhydrosugars; but this process involves removal of large amount of water from biomass that renders it energy intensive and thereby impractical. In this work passivation of the AAEM (making them less active or inactive) using mineral acid infusion was explored that will increase the yield of anhydrosugars from fast pyrolysis of biomass. Mineral acid infusion was tried by previous researchers, but the possibility of chemical reactions between infused acid and AAEM in the biomass appears to have been overlooked, possibly because metal cations might be expected to already be substantially complexed to chlorine or other strong anions that are found in biomass. Likewise, it appears that previous researchers assumed that as long as AAEM cations were in the biomass, they would be catalytically active regardless of the nature of their complexion with anions. On the contrary, we hypothesized that AAEM can be converted to inactive or less active salts using mineral acids. Various biomass feedstocks were infused with mineral (hydrochloric, nitric, sulfuric and

  1. Delayed bowel perforation following suprapubic catheter insertion

    Directory of Open Access Journals (Sweden)

    Mehta Ajay

    2004-12-01

    Full Text Available Abstract Background Complications of suprapubic catheter insertion are rare but can be significant. We describe an unusual complication of a delayed bowel perforation following suprapubic catheter insertion. Case presentation A gentleman presented with features of peritonitis and feculent discharge along a suprapubic catheter two months after insertion of the catheter. Conclusion Bowel perforation is the most feared complication of suprapubic catheter insertion especially in patients with lower abdominal scar. The risk may be reduced with the use of ultrasound scan guidance.

  2. Nozzle insert for mixed mode fuel injector

    Science.gov (United States)

    Lawrence, Keith E.

    2006-11-21

    A fuel injector includes a homogenous charge nozzle outlet set and a conventional nozzle outlet set controlled respectively, by first and second needle valve members. The homogeneous charged nozzle outlet set is defined by a nozzle insert that is attached to an injector body, which defines the conventional nozzle outlet set. The nozzle insert is a one piece metallic component with a large diameter segment separated from a small diameter segment by an annular engagement surface. One of the needle valve members is guided on an outer surface of the nozzle insert, and the nozzle insert has an interference fit attachment to the injector body.

  3. A HTS dipole insert coil constructed

    CERN Document Server

    Ballarino, A; Rey, J M; Stenvall, A; Sorbi, M; Tixador, P

    2013-01-01

    This report is the deliverable report 7.4.1 “A HTS dipole insert coil constructed“. The report has three parts: “Design report for the HTS dipole insert”, “One insert pancake prototype coil constructed with the setup for a high field test”, and “All insert components ordered”. The three report parts show that, although the insert construction will be only completed by end 2013, all elements are present for a successful completion and that, given the important investments done by the participants, there is a full commitment of all of them to finish the project

  4. [Audiometry in the cellulose industry].

    Science.gov (United States)

    Corrao, C R; Milano, L; Pedulla, P; Carlesi, G; Bacaloni, A; Monaco, E

    1993-01-01

    A noise level dosimetry and audiometric testing were conducted in a cellulose factory to determine the hazardous noise level and the prevalence of noise induced hearing loss among the exposed workers. The noise level was recorded up to 90 db (A) in several working areas. 18 workers, potentially exposed to noise injury, evidenced a significant hearing loss. While no evidence of noise injury was recorded in a control group of 100 subjects. This finding suggest a strict relationship between audiometric tests, the noise level recorded in the working place and the working seniority of exposed employers. PMID:7720969

  5. Noise Making Genes in the Oxygen-18 Climate Signal of Tree-Ring Cellulose

    Science.gov (United States)

    Sternberg, L.; Ellsworth, P.

    2008-12-01

    Previous studies showed that the δ18O values of the oxygen attached to the second carbon of the cellulose glucose moieties (δ18OC-2) adds biochemical noise to the 18O climate signal of cellulose. We expanded the above study to include tree ring sequences to see if this noise persists across time within an individual. The δ18OC-2 noise persists and the δ18O value of the cellulose derivative not having this "noisy" oxygen δ18OP-G is a superior predictor of plant water and relative humidity. We previously proposed that the isotopic noise may be generated by synthesis of polyols (sugar alcohols), since the isotopic noise was particularly strong in areas of plant water or temperature stress. It is well known that plants generate polyols, such as mannitol or inositol to protect membrane structure and build up osmotic pressure under stressful conditions. A survey of previously published leaf cellulose δ18O values shows that, indeed, polyol producing plants tend to have lower oxygen isotope ratios. A working hypothesis based on the reactions of the oxygen attached to the second carbon of the glucose moieties was developed and tested with genetically modified Arabidopsis thaliana var. Columbia. A A. thaliana line genetically modified by the insertion of a mannitol synthesis gene (Mannose 6-Phosphate Reductase) and another mutant line which cannot synthesize starch (lacking plastid Phosphoglucose Mutase) showed significantly lower δ18O values of stem cellulose compared to the wild type. The primary cause of this lower isotopic value of the whole cellulose molecule was lower δ18OC-2 values. These results are consistent with our working hypothesis.

  6. Rheological characterization of microcrystalline cellulose and silicified microcrystalline cellulose wet masses using a mixer torque rheometer.

    Science.gov (United States)

    Luukkonen, P; Schaefer, T; Hellén, L; Juppo, A M; Yliruusi, J

    1999-10-25

    The rheological properties of silicified microcrystalline cellulose (Prosolv 50) were compared with those of standard grades of microcrystalline cellulose (Emcocel 50 and Avicel PH 101). Cellulose samples were analyzed using nitrogen adsorption together with particle size, flowability, density and swelling volume studies. The rheological behaviour of the wet powder masses was studied as a function of mixing time using a mixer torque rheometer (MTR). Silicified microcrystalline cellulose exhibited improved flow characteristics and increased specific surface area compared to standard microcrystalline cellulose grades. Although the silicification process affected the swelling properties and, furthermore, the mixing kinetics of microcrystalline cellulose, the source of the microcrystalline cellulose had a stronger influence than silicification on the liquid requirement at peak torque. PMID:10518674

  7. Effect of rheological properties of dissolved cellulose/microfibrillated cellulose blend suspensions on film forming.

    Science.gov (United States)

    Saarikoski, Eve; Rissanen, Marja; Seppälä, Jukka

    2015-03-30

    Enzymatically treated cellulose was dissolved in a NaOH/ZnO solvent system and mixed together with microfibrillated cellulose (MFC) in order to find the threshold in which MFC fibers form a percolation network within the dissolved cellulose solution and in order to improve the properties of regenerated cellulose films. In the aqueous state, correlations between the rheological properties of dissolved cellulose/MFC blend suspensions and MFC fiber concentrations were investigated and rationalized. In addition, rheological properties of diluted MFC suspensions were characterized and a correlation with NaOH concentration was found, thus partly explaining the flow properties of dissolved cellulose/MFC blend suspensions. Finally, based on results from Dynamic Mechanical Analysis (DMA), MFC addition had strengthening/plasticizing effect on regenerated cellulose films if low concentrations of MFC, below the percolation threshold (5.5-6 wt%, corresponding to 0.16-0.18 wt% of MFC in the blend suspensions), were used. PMID:25563945

  8. Cellulose nanocrystals: synthesis, functional properties, and applications

    Directory of Open Access Journals (Sweden)

    George J

    2015-11-01

    Full Text Available Johnsy George, SN Sabapathi Food Engineering and Packaging Division, Defence Food Research Laboratory, Siddarthanagar, Mysore, Karnataka, India Abstract: Cellulose nanocrystals are unique nanomaterials derived from the most abundant and almost inexhaustible natural polymer, cellulose. These nanomaterials have received significant interest due to their mechanical, optical, chemical, and rheological properties. Cellulose nanocrystals primarily obtained from naturally occurring cellulose fibers are biodegradable and renewable in nature and hence they serve as a sustainable and environmentally friendly material for most applications. These nanocrystals are basically hydrophilic in nature; however, they can be surface functionalized to meet various challenging requirements, such as the development of high-performance nanocomposites, using hydrophobic polymer matrices. Considering the ever-increasing interdisciplinary research being carried out on cellulose nanocrystals, this review aims to collate the knowledge available about the sources, chemical structure, and physical and chemical isolation procedures, as well as describes the mechanical, optical, and rheological properties, of cellulose nanocrystals. Innovative applications in diverse fields such as biomedical engineering, material sciences, electronics, catalysis, etc, wherein these cellulose nanocrystals can be used, are highlighted. Keywords: sources of cellulose, mechanical properties, liquid crystalline nature, surface modification, nanocomposites 

  9. Multipurpose Transposon-Insertion Libraries in Yeast.

    Science.gov (United States)

    Kumar, Anuj

    2016-01-01

    Libraries of transposon-insertion alleles constitute powerful and versatile tools for large-scale analysis of yeast gene function. Transposon-insertion libraries are constructed most simply through mutagenesis of a plasmid-based genomic DNA library; modification of the mutagenizing transposon by incorporation of yeast selectable markers, recombination sites, and an epitope tag enables the application of insertion alleles for phenotypic screening and protein localization. In particular, yeast genomic DNA libraries have been mutagenized with modified bacterial transposons carrying the URA3 marker, lox recombination sites, and sequence encoding multiple copies of the hemagglutinin (HA) epitope. Mutagenesis with these transposons has yielded a large resource of insertion alleles affecting nearly 4000 yeast genes in total. Through well-established protocols, these insertion libraries can be introduced into the desired strain backgrounds and the resulting insertional mutants can be screened or systematically analyzed. Relative to alternative methods of UV irradiation or chemical mutagenesis, transposon-insertion alleles can be easily identified by PCR-based approaches or high-throughput sequencing. Transposon-insertion libraries also provide a cost-effective alternative to targeted deletion approaches, although, in contrast to start-codon to stop-codon deletions, insertion alleles might not represent true null-mutants. For protein-localization studies, transposon-insertion alleles can provide encoded epitope tags in-frame with internal codons; in many cases, these transposon-encoded epitope tags can provide a more accurate localization for proteins in which terminal sequences are crucial for intracellular targeting. Thus, overall, transposon-insertion libraries can be used quickly and economically and have a particular utility in screening for desired phenotypes and localization patterns in nonstandard genetic backgrounds. PMID:27250950

  10. Radiation pretreatment of cellulose for energy production

    Science.gov (United States)

    Dela Rosa, A. M.; Dela Mines, A. S.; Banzon, R. B.; Simbul-Nuguid, Z. F.

    The effect of radiation pretreatment of agricultural cellulosic wastes was investigated through hydrolytic reactions of cellulose. Gamma irradiation significantly increased the acid hydrolysis of rice straw, rice hull and corn husk. The yields of reducing sugar were higher with increasing radiation dose in these materials. The observed radiation effect varied with the cellulosic material but it correlated with neither the cellulose content nor the lignin content. Likewise, the radiation pretreatment accelerated the subsequent enzymatic hydrolysis of rice straw and rice hull by cellulase. The irradiated rice straw appeared to be a better growth medium for the cellulolytic microorganism, Myrothecium verrucaria, than the non-irradiated material. This was attributed to increased digestibility of the cellulose by the microorganism.

  11. Radiation pretreatment of cellulose for energy production

    International Nuclear Information System (INIS)

    The effect of radiation pretreatment of agricultural cellulosic wastes was investigated through hydrolytic reactions of cellulose. Gamma irradiation significantly increased the acid hydrolysis of rice straw, rice hull and corn husk. The yields of reducing sugar were higher with increasing radiation dose in these materials. The observed radiation effect varied with the cellulose material but it correlated with neither the cellulose content nor the lignin content. Likewise, the radiation pretreatment accelerated the subsequent enzymatic hydrolysis of rice straw and rice hull by cellulase. The irradiated rice straw appeared to be a better growth medium for the cellulolytic microorganism, Myrothecium verrucaria, than the non-irradiated material. This was attributed to increased digestibility of the cellulose by the microorganism. (author)

  12. Single-cell protein from waste cellulose

    Science.gov (United States)

    Dunlap, C. E.; Callihan, C. D.

    1973-01-01

    The recycle, reuse, or reclamation of single cell protein from liquid and solid agricultural waste fibers by a fermentation process is reported. It is shown that cellulose comprises the bulk of the fibers at 50% to 55% of the dry weight of the refuse and that its biodegradability is of prime importance in the choice of a substrate. The application of sodium hydroxide followed by heat and pressure serves to de-polymerize and disrupt lignin structure while swelling the cellulose to increase water uptake and pore volume. Some of the lignin, hemi-celluloses, ash, and cellulose of the material is hydrolized and solubilized. Introduction of microorganisms to the substrate fibers mixed with nutrients produces continuous fermentation of cellulose for further protein extraction and purification.

  13. Dosimetry of a New P-32 Ophthalmic Applicator

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Chang Heon; Ye, Sung-Joon [Department of Radiation Oncology, Seoul National University College of Medicine, Seoul Korea 110-744 (Korea, Republic of); Han, Hyon Soo; Son, Kwang-Jae; Park, Ul Jae, E-mail: sye@snu.ac.k [Hanaro Applications Research, Korea Atomic Energy Research Institute, Daejeon Korea 305-353 (Korea, Republic of)

    2010-11-01

    Purpose: A {sup 90}Sr/Y applicator has been used as a {beta}-source for postoperative irradiation after pterygium excision. As an alternative to {sup 90}Sr/Y irradiation, we proposed treatments with {sup 32}P. This study aims to provide the dosimetry for this new applicator. Method and Materials: A {sup 32}P ophthalmic applicator, of which the design and materials were optimally designed by Monte Carlo simulations, was fabricated by the Korea Atomic Energy Research Institute. The absorbed dose at the front surface of the cylindrical {sup 32}P applicator was measured by using an extrapolation ionization chamber. Radiochromic film (RCF) was used to measure depth dose distributions and dose profiles at various depths. A micro-MOSFET detector was used for depth dose measurements. Results: The absorbed dose rates to the reference point (i.e., at the centre on the front surface of {sup 32}P applicator) were 0.238 {+-} 0.012 cGy/s for an extrapolation ionization chamber, 0.280 {+-} 0.001 cGy/s for RCF, and 0.257 {+-} 0.020 cGy/s for MOSFET. The axial depth dose rate was reduced into approximately 1/10 as {sup 32}P betas penetrate every 2 mm depth. Measured data in depths of 1 mm to 3.5 mm agreed with Monte Carlo data. Due to non-uniform absorption of {sup 32}P into an absorbent disk, the dose at the centre of trans-axial plane was 2%-4% less than the peak dose around the periphery. We confirmed no leakage of {sup 32}P activities and negligible exposure rate around the hand grip of the applicator. Conclusions: The {sup 32}P applicator can deliver uniform therapeutic doses to the surface of the conjunctiva, while sparing the lens better than {sup 90}Sr/Y applicators. The doses at any points from the {sup 32}P applicator can be calculated by using these measured data sets. The safety of {sup 32}P applicator was confirmed. However, prior to the clinical application of every new applicator, safety, dose uniformity, and absorbed dose rate at the reference point should be

  14. Dosimetry of a New P-32 Ophthalmic Applicator

    International Nuclear Information System (INIS)

    Purpose: A 90Sr/Y applicator has been used as a β-source for postoperative irradiation after pterygium excision. As an alternative to 90Sr/Y irradiation, we proposed treatments with 32P. This study aims to provide the dosimetry for this new applicator. Method and Materials: A 32P ophthalmic applicator, of which the design and materials were optimally designed by Monte Carlo simulations, was fabricated by the Korea Atomic Energy Research Institute. The absorbed dose at the front surface of the cylindrical 32P applicator was measured by using an extrapolation ionization chamber. Radiochromic film (RCF) was used to measure depth dose distributions and dose profiles at various depths. A micro-MOSFET detector was used for depth dose measurements. Results: The absorbed dose rates to the reference point (i.e., at the centre on the front surface of 32P applicator) were 0.238 ± 0.012 cGy/s for an extrapolation ionization chamber, 0.280 ± 0.001 cGy/s for RCF, and 0.257 ± 0.020 cGy/s for MOSFET. The axial depth dose rate was reduced into approximately 1/10 as 32P betas penetrate every 2 mm depth. Measured data in depths of 1 mm to 3.5 mm agreed with Monte Carlo data. Due to non-uniform absorption of 32P into an absorbent disk, the dose at the centre of trans-axial plane was 2%-4% less than the peak dose around the periphery. We confirmed no leakage of 32P activities and negligible exposure rate around the hand grip of the applicator. Conclusions: The 32P applicator can deliver uniform therapeutic doses to the surface of the conjunctiva, while sparing the lens better than 90Sr/Y applicators. The doses at any points from the 32P applicator can be calculated by using these measured data sets. The safety of 32P applicator was confirmed. However, prior to the clinical application of every new applicator, safety, dose uniformity, and absorbed dose rate at the reference point should be carefully evaluated by the method developed in this study.

  15. Photophysics of alloxazines on cellulose.

    Science.gov (United States)

    Sikorski, Marek; Sikorska, Ewa; Khmelinskii, Igor V; Gonzalez-Moreno, Rafael; Bourdelande, José L; Siemiarczuk, Aleksander

    2002-09-01

    We report the UV-Vis absorption, fluorescence and transient absorption spectra of selected methylalloxazines adsorbed on cellulose from a polar solvent. The ground-state properties of these probe molecules in the cellulose matrix are similar to those in polar protic solvents. Fluorescence decay data allowed identification of three emitting species for every molecule studied, excluding 1-methyllumichrome which lacks the capacity to rearrange into an isoalloxazinic form. The short-lived emission component was attributed to the neutral form of the molecule, and the two longer-lived components were assigned to the two distinct deprotonated monoanionic forms resulting from dissociation at the respective N(3) and N(1) nitrogen atoms. The two monoanions coexist due to their very similar pKa, values. Transient absorption experiments detected two species created by the laser pulse in these systems. The short-lived species was identified as the triplet excited state, and the long-lived species as the semireduced radical, formed by hydrogen atom or proton transfer from the glycosidic unit to the alloxazine carbonyl group. PMID:12665311

  16. Anaerobic digestion of cellulosic wastes

    International Nuclear Information System (INIS)

    Anaerobic digestion is a potentially attractive technology for volume reduction of low-level radioactive cellulosic wastes. A substantial fraction of the waste is converted to off-gas and a relatively small volume of biologically stabilized sludge is produced. Process development work has been completed using a 75-L digester to verify rates and conversions obtained at the bench scale. Start-up and operating procedures have been developed, and effluent was generated for characterization and disposal studies. Three runs using batch and fed-batch conditions were made lasting 36, 90, and 423 d. Solids solubilization rates and gas production rates averaged approximately 1.8 g cellulose per L of reactor per d and 1.2 L of off-gas per L reactor per d. Greater than 80% destruction of the volatile suspended solids was obtained. A simple dynamic process model was constructed to aid in process design and for use in process monitoring and control of a large-scale digester

  17. Anaerobic digestion of cellulosic wastes

    International Nuclear Information System (INIS)

    Anaerobic digestion is a potentially attractive technology for volume reduction of cellulosic wastes. A substantial fraction of the waste is converted to off-gas and a relatively small volume of biologically stabilized sludge is produced. Process development work is underway using a 75-L digester to verify rates and conversions obtained at the bench scale, to develop start-up and operating procedures, and to generate effluent for characterization and disposal studies. Three runs using batch and batch-fed conditions have been made lasting 36, 90, and over 200 days. Solids solubilization and gas production rates and total solids destruction have met or exceeded the target values of 0.6 g cellulose per L of reactor per day, 0.5 L off-gas per L of reactor per day, and 80% destruction of solids, respectively. Successful start-up procedures have been developed, and preliminary effluent characterization and disposal studies have been done. A simple dynamic process model has been constructed to aid in further process development and for use in process monitoring and control of a large-scale digester. 7 references, 5 figures, 1 table

  18. Brainstem auditory evoked responses and ophthalmic findings in llamas and alpacas in eastern Canada

    OpenAIRE

    Webb, Aubrey A.; Cullen, Cheryl L.; Lamont, Leigh A.

    2006-01-01

    Seventeen llamas and 23 alpacas of various coat and iris colors were evaluated for: 1) deafness by using brainstem auditory evoked response testing; and 2) for ocular abnormalities via complete ophthalmic examination. No animals were deaf. The most common ocular abnormalities noted were iris-to-iris persistent pupillary membranes and incipient cataracts.

  19. 78 FR 9349 - Medical Devices; Ophthalmic Devices; Classification of the Eyelid Weight

    Science.gov (United States)

    2013-02-08

    ... seq.), as amended by the Medical Device Amendments of 1976 (Pub. L. 94-295), the Safe Medical Devices.../downloads/MedicalDevices/DeviceRegulationandGuidance/Overview/MedicalDeviceUserFeeandModernizationActMDUFMA... HUMAN SERVICES Food and Drug Administration 21 CFR Part 886 Medical Devices; Ophthalmic...

  20. 78 FR 68714 - Medical Devices; Ophthalmic Devices; Classification of the Scleral Plug

    Science.gov (United States)

    2013-11-15

    ... Device Amendments of 1976 (the 1976 amendments) (Pub. L. 94-295), the Safe Medical Devices Act of 1990... HUMAN SERVICES Food and Drug Administration 21 CFR Part 886 Medical Devices; Ophthalmic Devices... regulation of medical devices intended for human use. Section 513 of the FD&C Act (21 U.S.C....

  1. 78 FR 5327 - Medical Devices; Ophthalmic Devices; Classification of the Scleral Plug

    Science.gov (United States)

    2013-01-25

    ... HUMAN SERVICES Food and Drug Administration 21 CFR Part 886 Medical Devices; Ophthalmic Devices...), the Safe Medical Devices Act of 1990 (Pub. L. 101-629), the Food and Drug Administration Modernization... the regulation of medical devices intended for human use. Section 513 of the FD&C Act (21 U.S.C....

  2. Staff dose of hospitalization in the treatment of patients in ophthalmic brachytherapy with 125 I

    International Nuclear Information System (INIS)

    The objective of this work, therefore, has been the evaluation of the dose levels which nursing staff can receive in care for ophthalmic brachytherapy patients treated with 125 I from measurements made on the same, evaluating, in an experimental way, job security following the PR rules laid down for these treatments. (Author)

  3. Generalized ray tracing method for the calculation of the peripheral refraction induced by an ophthalmic lens

    Science.gov (United States)

    Rojo, Pilar; Royo, Santiago; Caum, Jesus; Ramírez, Jorge; Madariaga, Ines

    2015-02-01

    Peripheral refraction, the refractive error present outside the main direction of gaze, has lately attracted interest due to its alleged relationship with the progression of myopia. The ray tracing procedures involved in its calculation need to follow an approach different from those used in conventional ophthalmic lens design, where refractive errors are compensated only in the main direction of gaze. We present a methodology for the evaluation of the peripheral refractive error in ophthalmic lenses, adapting the conventional generalized ray tracing approach to the requirements of the evaluation of peripheral refraction. The nodal point of the eye and a retinal conjugate surface will be used to evaluate the three-dimensional distribution of refractive error around the fovea. The proposed approach enables us to calculate the three-dimensional peripheral refraction induced by any ophthalmic lens at any direction of gaze and to personalize the lens design to the requirements of the user. The complete evaluation process for a given user prescribed with a -5.76D ophthalmic lens for foveal vision is detailed, and comparative results obtained when the geometry of the lens is modified and when the central refractive error is over- or undercorrected. The methodology is also applied for an emmetropic eye to show its application for refractive errors other than myopia.

  4. 21 CFR 524.1662b - Oxytetracycline hydrochloride, polymyxin B sulfate ophthalmic ointment.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Oxytetracycline hydrochloride, polymyxin B sulfate... DOSAGE FORM NEW ANIMAL DRUGS § 524.1662b Oxytetracycline hydrochloride, polymyxin B sulfate ophthalmic ointment. (a) Specifications. Each gram of the ointment contains oxytetracycline hydrochloride...

  5. Can ophthalmic drops cause central nervous system depression and cardiogenic shock in infants?

    Science.gov (United States)

    Kiryazov, Kiril; Stefova, Mariyka; Iotova, Violeta

    2013-11-01

    Topical ocular medications have been widely prescribed and successfully used in children for the management of different ophthalmic disorders. We present 2 infants admitted to our pediatric intensive care unit who developed altered state of consciousness, hypotonia, hypothermia, bradycardia, and apnea after instillation of ophthalmic drops. The second infant also had hypotension and broncho-obstruction. Few days before admission, both infants were diagnosed with congenital glaucoma, and topical antiglaucoma treatment was initiated. Ophthalmic drops with brimonidine and brinzolamide were prescribed to both patients, whereas the second infant also received topical timolol. After elimination of other possible causes, the diagnosis of intoxication with topical antiglaucoma medications was established. After discontinuation of eye drops and vigorous symptomatic treatment, both infants recovered without sequels. Topically applied ophthalmic drops may cause life-threatening systemic adverse effects in infants, such as central nervous system depression and cardiogenic shock. Moreover, these 2 patients illustrate the importance of careful evaluation of all topical medications and their consideration as possible causes of the derangements in critically ill infants. PMID:24196091

  6. Doses of radiation in the environment of patients undergoing treatment of ophthalmic brachytherapy

    International Nuclear Information System (INIS)

    This paper presents results for measures of dose made to different patient undergoing treatment with ophthalmic brachytherapy. The aim of these measures has been, on the one hand, verify assessments relating to radiation protection in the memory of the installation and, on the other hand, experimental measures that can serve to reduce the perception of the radiological risk professionals have. (Author)

  7. 76 FR 78150 - Ophthalmic and Topical Dosage Form New Animal Drugs; Hydrocortisone Aceponate, Miconazole Nitrate...

    Science.gov (United States)

    2011-12-16

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration 21 CFR Part 524 Ophthalmic and Topical Dosage Form New... to the Center for Veterinary Medicine, 21 CFR part 524 is amended as follows: PART...

  8. Surface dose rate measurement of 90Sr/90Y ophthalmic applicator: a comparative study

    International Nuclear Information System (INIS)

    Removable ophthalmic plaques are used in treatment of malignant melanoma of the uvea, post-operative irradiation in treatment of pterygium and other superficial lesions. 90Sr/90Y ophthalmic applicator uses 90Y(T1/2 64 hours) present in secular equilibrium with its parent 90Sr(T1/2 = 28 years). Filters (AI, Stainless Steel) in the front surface flatten the energy spectrum, absorb most of the low energy beta particles from 90Sr (0.54 MeV) and also permits the high-energy beta from 90Y (2.27 MeV) to enter the eye. Different methods have been used to quantify surface dose rate of ophthalmic applicators. Surface dose rate representing the applicator characteristic allows a convenient way for evaluation and correlation of results using different procedures. Experiments were performed to measure the surface dose rate of 90Sr/90Y planar ophthalmic applicator (Tracerlab, U.S.A.) by the reference method using extrapolation chamber and the GAFChromic MD-55 films

  9. BRIEF COMMUNICATIONS: Use of planar axially asymmetric focusers in laser ophthalmic surgery

    Science.gov (United States)

    Akopyan, V. S.; Danileĭko, Yu K.; Danilov, V. A.; Naumidi, L. P.; Popov, V. V.; Sisakyan, I. N.

    1985-02-01

    Planar focusers ensuring formation of an axially asymmetric distribution of the intensity of CO2 laser radiation, of the type used in ophthalmic surgery, are described and considered. Special attention is given to laser treatment of myopia (laser keratotomy). The promising nature of the proposed method is demonstrated.

  10. A Flip Turn for Membrane Protein Insertion

    OpenAIRE

    Shao, Sichen; Hegde, Ramanujan S.

    2011-01-01

    The transmembrane domains in a membrane protein must be recognized and correctly oriented before their insertion into the lipid bilayer. Devaraneni et al. (2011) generate snapshots at different stages of membrane protein biogenesis, revealing a dynamic set of steps that imply an unexpectedly flexible membrane insertion machinery.

  11. Hydrothermal degradation of cellulosic matter to sugars and their fermentative conversion to protein

    International Nuclear Information System (INIS)

    For the hydrothermal degradation of cellulosic matter, an apparatus was developed in which water is used as extraction medium. Samples, 0.15 g each, of pure cellulose (filter paper), natural straw, and 14C-labeled straw were treated at temperatures of between 200 and 2750C. Of the inserted cellulose, 65.7 percent was recovered at the optimum temperature as sugars and hydroxymethylfurfural. It was possible to degrade the straw selectively: at lower temperatures, the hemicellulose part of the plant matter was converted to xylose and arabinose; and then at higher temperatures, the cellulose was converted to glucose and cellobiose. At the same time, a certain amount of the sugars was transformed to furfural compounds. The growth behavior of the yeast Candida utilis (strain Weissenbach) was analyzed, using cellobiose, xylose, and glucose (standard) as carbon sources. The growth curves applying cellobiose were nearly identical to those of glucose. Xylose showed lower productivity than the hexoses. The main products of the hydrothermal degradation can, therefore, be used favorably as nutritive substances for this protein-producing yeast

  12. Simulations of Cellulose Translocation in the Bacterial Cellulose Synthase Suggest a Regulatory Mechanism for the Dimeric Structure of Cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Knott, Brandon C.; Crowley, Michael F.; Himmel, Michael E.; Zimmer, Jochen; Beckham, Gregg T.

    2016-05-01

    The processive cycle of the bacterial cellulose synthase (Bcs) includes the addition of a single glucose moiety to the end of a growing cellulose chain followed by the translocation of the nascent chain across the plasma membrane. The mechanism of this translocation and its precise location within the processive cycle are not well understood. In particular, the molecular details of how a polymer (cellulose) whose basic structural unit is a dimer (cellobiose) can be constructed by adding one monomer (glucose) at a time are yet to be elucidated. Here, we have utilized molecular dynamics simulations and free energy calculations to the shed light on these questions. We find that translocation forward by one glucose unit is quite favorable energetically, giving a free energy stabilization of greater than 10 kcal mol-1. In addition, there is only a small barrier to translocation, implying that translocation is not rate limiting within the Bcs processive cycle (given experimental rates for cellulose synthesis in vitro). Perhaps most significantly, our results also indicate that steric constraints at the transmembrane tunnel entrance regulate the dimeric structure of cellulose. Namely, when a glucose molecule is added to the cellulose chain in the same orientation as the acceptor glucose, the terminal glucose freely rotates upon forward motion, thus suggesting a regulatory mechanism for the dimeric structure of cellulose. We characterize both the conserved and non-conserved enzyme-polysaccharide interactions that drive translocation, and find that 20 of the 25 residues that strongly interact with the translocating cellulose chain in the simulations are well conserved, mostly with polar or aromatic side chains. Our results also allow for a dynamical analysis of the role of the so-called 'finger helix' in cellulose translocation that has been observed structurally. Taken together, these findings aid in the elucidation of the translocation steps of the Bcs

  13. Central Solenoid Insert Technical Specification

    Energy Technology Data Exchange (ETDEWEB)

    Martovetsky, Nicolai N [ORNL; Smirnov, Alexandre [ORNL

    2011-09-01

    The US ITER Project Office (USIPO) is responsible for the ITER central solenoid (CS) contribution to the ITER project. The Central Solenoid Insert (CSI) project will allow ITER validation the appropriate lengths of the conductors to be used in the full-scale CS coils under relevant conditions. The ITER Program plans to build and test a CSI to verify the performance of the CS conductor. The CSI is a one-layer solenoid with an inner diameter of 1.48 m and a height of 4.45 m between electric terminal ends. The coil weight with the terminals is approximately 820 kg without insulation. The major goal of the CSI is to measure the temperature margin of the CS under the ITER direct current (DC) operating conditions, including determining sensitivity to load cycles. Performance of the joints, ramp rate sensitivity, and stability against thermal or electromagnetic disturbances, electrical insulation, losses, and instrumentation are addressed separately and therefore are not major goals in this project. However, losses and joint performance will be tested during the CSI testing campaign. The USIPO will build the CSI that will be tested at the Central Solenoid Model Coil (CSMC) Test Facility at the Japan Atomic Energy Agency (JAEA), Naka, Japan. The industrial vendors (the Suppliers) will report to the USIPO (the Company). All approvals to proceed will be issued by the Company, which in some cases, as specified in this document, will also require the approval of the ITER Organization. Responsibilities and obligations will be covered by respective contracts between the USIPO, called Company interchangeably, and the industrial Prime Contractors, called Suppliers. Different stages of work may be performed by more than one Prime Contractor, as described in this specification. Technical requirements of the contract between the Company and the Prime Contractor will be covered by the Fabrication Specifications developed by the Prime Contractor based on this document and approved by

  14. Pharmacopoeial and physicochemical properties of α-cellulose and microcrystalline cellulose powders derived from cornstalks

    Directory of Open Access Journals (Sweden)

    Chukwuemeka P Azubuike

    2012-01-01

    Full Text Available Background: Suitable α-cellulose and microcrystalline cellulose powders for use in the pharmaceutical industry can be derived from agricultural wastes. Aims: The pharmacopoeial and physicochemical properties of cornstalk α-cellulose (CCC and cornstalk microcrystalline cellulose powders (MCCC were compared to a commercial brand of microcrystalline cellulose (Avicel PH101 to evaluate their usefulness as pharmaceutical excipients. Settings and Design: Physicochemical properties of an excipient play a very crucial role in the functions of the excipient; hence, these properties were evaluated and compared with a commercial brand. Materials and Methods: α-cellulose was extracted from cornstalks. Modification of this α-cellulose powder was carried out by its partial hydrolysis with hydrochloric acid (HCl to obtain a microcrystalline cellulose powder. Their pharmacopoeial, physicochemical and microbiological properties were evaluated using standard methods. Statistical Analysis: OriginPro 8 SR2 v. 0891 (B891 software (OriginLab Corporation USA was used for statistical evaluation. One-way analysis of variance was used to differentiate between samples and decide where significant differences were established. Results: The yield of α-cellulose from the cornstalks was 32.5%w/w and that of microcrystalline cellulose 26%w/w. All the cellulose samples met all the pharmacopoeial parameters that were carried out. The comparison of physicochemical properties of the CCC, MCCC and Avicel PH101 suggests that the microcrystalline celluloses might have better flow and compression properties than the CCC sample. The three cellulose powders were of high microbial excipient quality. For almost all parameters evaluated, it was generally observed that the MCCC has similar characteristics to Avicel PH101. Conclusions: MCCC can be a suitable alternative to the expensive Avicel PH101as pharmaceutical excipients.

  15. Degradation of cellulose by basidiomycetous fungi.

    Science.gov (United States)

    Baldrian, Petr; Valásková, Vendula

    2008-05-01

    Cellulose is the main polymeric component of the plant cell wall, the most abundant polysaccharide on Earth, and an important renewable resource. Basidiomycetous fungi belong to its most potent degraders because many species grow on dead wood or litter, in environment rich in cellulose. Fungal cellulolytic systems differ from the complex cellulolytic systems of bacteria. For the degradation of cellulose, basidiomycetes utilize a set of hydrolytic enzymes typically composed of endoglucanase, cellobiohydrolase and beta-glucosidase. In some species, the absence of cellobiohydrolase is substituted by the production of processive endoglucanases combining the properties of both of these enzymes. In addition, systems producing hydroxyl radicals based on cellobiose dehydrogenase, quinone redox cycling or glycopeptide-based Fenton reaction are involved in the degradation of several plant cell wall components, including cellulose. The complete cellulolytic complex used by a single fungal species is typically composed of more than one of the above mechanisms that contribute to the utilization of cellulose as a source of carbon or energy or degrade it to ensure fast substrate colonization. The efficiency and regulation of cellulose degradation differs among wood-rotting, litter-decomposing, mycorrhizal or plant pathogenic fungi and yeasts due to the different roles of cellulose degradation in the physiology and ecology of the individual groups. PMID:18371173

  16. Recycling of cellulosic fibers by enzymatic process.

    Science.gov (United States)

    Shojaei, K M; Dadashian, F; Montazer, M

    2012-02-01

    In this research, enzymatic treatment as an environmental friendly process has been used for recycling process of old cellulosic wastes such as cotton, viscose, and lyocell. Cellulase hydrolyses cellulosic chains and shortens cellulosic fibers. This study investigates to detect the optimum enzyme concentration and time of treatments for suitable changes of length and weight loss. The main purposes of this article are shortening of cellulosic fibers and evaluating of enzymatic treatment in different kind of cellulosic fibers. According to the data of experiments, with the increase of enzyme concentration and the treatment time, the length and weight loss percentage of the cellulosic fibers has been decreased. The length and weight loss percentage of treated viscose is more than that of lyocell and cotton fibers. Optimized condition, reaction time, and enzyme concentration have been determined by mean length of treated cellulosic samples. Suitable longitudinal distribution of fiber for papermaking industries is in the range of 0 to 4 mm. Optimum enzyme concentration and treatment time for recycling cotton, lyocell, and viscose fibers are 2% and 48 h for cotton and lyocell and 0.5% and 48 h for viscose, respectively. According to the data of experiment, the length of treated fibers is appropriate for its usage as a raw material in papermaking industries. PMID:22161212

  17. A novel cellulose hydrogel prepared from its ionic liquid solution

    Institute of Scientific and Technical Information of China (English)

    LI Lu; LIN ZhangBi; YANG Xiao; WAN ZhenZhen; CUI ShuXun

    2009-01-01

    A novel cellulose hydrogel is prepared by regenerating cellulose from its ionic liquid solution. The transparency cellulose hydrogel presents a good chemical stability and an acceptable mechanical property. This non-toxic cellulose hydrogel should be biocompatibie and may be useful in the future as a biomaterial.

  18. Colonization of Crystalline Cellulose by Clostridium cellulolyticum ATCC 35319

    OpenAIRE

    Gelhaye, E.; Gehin, A; Petitdemange, H.

    1993-01-01

    Cellulose colonization by Clostridium cellulolyticum was studied by using [methyl-3H]thymidine incorporation. The colonization process indicated that a part of the bacterial population was released from cellulose to the liquid phase before binding and colonizing another adhesion site of the cellulose. We postulate that cellulose colonization occurs according to the following process: adhesion, colonization, release, and readhesion.

  19. Surface modification of cellulose nanocrystals

    Institute of Scientific and Technical Information of China (English)

    WANG Neng; DING Enyong; CHENG Rongshi

    2007-01-01

    In order to improve the dispersibility of cellulose nanocrystal(CNC) particles,three difierent grafted reactions of acetylation,hydroxyethylation and hydroxypropylation were introduced to modify the CNC surface.The main advantages of these methods were the simple and easily controlled reaction conditions,and the dispersibility of the resulting products was distinctly improved.The properties of the modified CNC were characterized by means of Fourier transform infrared spectroscopy(FT-IR),13 C nuclear magnetic resonance(NMR),transmission electron microscopy(TEM)and thermogravimetric analyses(TGA).The results indicated mat after desiccation,the modification products could be dispersed again in the proper solvents by ultrasonic treatments,and the diameter of their particles had no obvious changes.However,their thermal degradation behaviors were quite different.The initial decomposition temperature of the modified products via hydroxyethylation or hydroxypropylation was lower than that of modified products via acetylation.

  20. A fuel insert shuffle planner expert system

    International Nuclear Information System (INIS)

    During the refueling outage of a pressurized water reactor, the fuel assembly inserts must be moved from their current fuel assemblies to the proper fuel assemblies for the next cycle core design. The crane movement pattern, or shuffle plan, to perform this operation should be as efficient as possible because a less efficient plan could cause the power plant to be shut down for a longer period of time. The current method to develop this plan requires three to four man-weeks of a reactor engineer's time. This plan is developed by the reactor engineer who uses his expertise from previous insert shuffles. Further modifications to this plan are sometimes required due to either changes in the desired core load pattern or damaged fuel or inserts. These changes generally require two to four man-days during the plant outage time. A full-scale prototype of an insert shuffle advisor expert system has been developed to create the insert shuffle plan. This system substantially reduces the manpower requirements needed to develop this plan. It is also a vehicle for preserving the expertise needed to develop this plan. Since the plan can be developed more quickly with the insert shuffle advisor, several strategies can be tried. This gives the potential for a more efficient insert shuffle plan than could be found by the reactor engineer. A more efficient plan means that the power plant could be shut down for a shorter period of time. This would have considerable financial advantages

  1. Lyocell, The New Generation of Regenerated Cellulose

    Directory of Open Access Journals (Sweden)

    Éva Borbély

    2008-06-01

    Full Text Available For the majority of the last century, commercial routes to regenerated cellulosefibres have coped with the difficulties of making a good cellulose solution by using an easyto dissolve derivative (e.g. xanthane in the case of viscose rayon or complex (e.g.cuprammonium rayon. For the purposes of this paper, advanced cellulosic fibres aredefined as those made from a process involving direct dissolution of cellulose. The firstexamples of such fibres have now been generically designaed as lyocell fibres todistinguish them from rayons, and the first commercial lyocell fibre is Courtaulds’ Tencel.

  2. Preparation of membranes from cellulose obtained of sugarcane bagasse

    International Nuclear Information System (INIS)

    In this work, cellulose obtained from sugarcane bagasse to produce both cellulose and acetylated cellulose to prepare asymmetric membranes. Membranes was procedure used a mixture of materials of DMAc/ LiCl systemic in different conditions. Cellulose and acetylated cellulose were characterized by thermogravimetric (TG), Xray diffraction (XRD) and scanning Electron Microscopy (SEM). Observed less stability thermal of acetylated cellulose when compared of cellulose. All membranes procedure were asymmetric, characterized by presence of a dense skin and porous support can be observed. SEM showed that the morphology of the superficial of membranes depends on the method preparation. (author)

  3. Hydrolyzability of xylan after adsorption on cellulose: Exploration of xylan limitation on enzymatic hydrolysis of cellulose.

    Science.gov (United States)

    Wang, Xiao; Li, Kena; Yang, Ming; Zhang, Junhua

    2016-09-01

    During pretreatment of lignocellulosic materials, the dissolved xylan would re-adsorb on cellulose, and then inhibits the cellulose hydrolysis by cellulases. However, the hydrolyzability of xylan adsorbed on cellulose is not clear. In this work, the adsorption behavior of xylans on celluloses and the hydrolysis of adsorbed xylan by xylanase (XYL) were investigated. The results indicated that the adsorption of beechwood xylan (BWX) and oat spelt xylan (OSX) on Avicel was conformed to Langmuir-type adsorption isotherm. Higher ion strength increased the adsorption of BWX on Avicel, but not that of OSX. Both BWX and OSX adsorbed on Avicel and corn stover after dilute acid pretreatment (CS-DA) could be hydrolyzed by XYL. Compared to OSX, BWX adsorbed on cellulosic materials could be more easily hydrolyzed by XYL. Thus, supplementation of XYL could hydrolyze the xylan adsorbed on cellulose and potentially improved hydrolysis efficiency of lignocelluloses. PMID:27185150

  4. Homogeneous preparation of cellulose acetate propionate (CAP) and cellulose acetate butyrate (CAB) from sugarcane bagasse cellulose in ionic liquid.

    Science.gov (United States)

    Huang, Kelin; Wang, Ben; Cao, Yan; Li, Huiquan; Wang, Jinshu; Lin, Weijiang; Mu, Chaoshi; Liao, Dankui

    2011-05-25

    Cellulose acetate butyrate (CAB) and cellulose acetate propionate (CAP) were prepared homogeneously in a 1-allyl-3-methylimidazolium chloride (AmimCl) ionic liquid system from sugarcane bagasse (SB). The reaction temperature, reaction time, and molar ratio of butyric (propionic) anhydride/anhydroglucose units in the cellulose affect the butyryl (B) or propionyl (P) content of CAB or CAP samples. The (13)C NMR data revealed the distribution of the substituents of CAB and CAP. The thermal stability of sugar cane bagasse cellulose was found by thermogravimetric analysis to have decreased after chemical modification. After reaction, the ionic liquid was effectively recycled and reused. This study provides a new way for high-value-added utilization of SB and realizing the objective of turning waste into wealth. PMID:21452895

  5. Insertions and the emergence of novel protein structure: a structure-based phylogenetic study of insertions

    Directory of Open Access Journals (Sweden)

    Blouin Christian

    2007-11-01

    Full Text Available Abstract Background In protein evolution, the mechanism of the emergence of novel protein domain is still an open question. The incremental growth of protein variable regions, which was produced by stochastic insertions, has the potential to generate large and complex sub-structures. In this study, a deterministic methodology is proposed to reconstruct phylogenies from protein structures, and to infer insertion events in protein evolution. The analysis was performed on a broad range of SCOP domain families. Results Phylogenies were reconstructed from protein 3D structural data. The phylogenetic trees were used to infer ancestral structures with a consensus method. From these ancestral reconstructions, 42.7% of the observed insertions are nested insertions, which locate in previous insert regions. The average size of inserts tends to increase with the insert rank or total number of insertions in the variable regions. We found that the structures of some nested inserts show complex or even domain-like fold patterns with helices, strands and loops. Furthermore, a basal level of structural innovation was found in inserts which displayed a significant structural similarity exclusively to themselves. The β-Lactamase/D-ala carboxypeptidase domain family is provided as an example to illustrate the inference of insertion events, and how the incremental growth of a variable region is capable to generate novel structural patterns. Conclusion Using 3D data, we proposed a method to reconstruct phylogenies. We applied the method to reconstruct the sequences of insertion events leading to the emergence of potentially novel structural elements within existing protein domains. The results suggest that structural innovation is possible via the stochastic process of insertions and rapid evolution within variable regions where inserts tend to be nested. We also demonstrate that the structure-based phylogeny enables the study of new questions relating to the

  6. Brittle Culm1, a COBRA-like protein, functions in cellulose assembly through binding cellulose microfibrils.

    Directory of Open Access Journals (Sweden)

    Lifeng Liu

    Full Text Available Cellulose represents the most abundant biopolymer in nature and has great economic importance. Cellulose chains pack laterally into crystalline forms, stacking into a complicated crystallographic structure. However, the mechanism of cellulose crystallization is poorly understood. Here, via functional characterization, we report that Brittle Culm1 (BC1, a COBRA-like protein in rice, modifies cellulose crystallinity. BC1 was demonstrated to be a glycosylphosphatidylinositol (GPI anchored protein and can be released into cell walls by removal of the GPI anchor. BC1 possesses a carbohydrate-binding module (CBM at its N-terminus. In vitro binding assays showed that this CBM interacts specifically with crystalline cellulose, and several aromatic residues in this domain are essential for binding. It was further demonstrated that cell wall-localized BC1 via the CBM and GPI anchor is one functional form of BC1. X-ray diffraction (XRD assays revealed that mutations in BC1 and knockdown of BC1 expression decrease the crystallite width of cellulose; overexpression of BC1 and the CBM-mutated BC1s caused varied crystallinity with results that were consistent with the in vitro binding assay. Moreover, interaction between the CBM and cellulose microfibrils was largely repressed when the cell wall residues were pre-stained with two cellulose dyes. Treating wild-type and bc1 seedlings with the dyes resulted in insensitive root growth responses in bc1 plants. Combined with the evidence that BC1 and three secondary wall cellulose synthases (CESAs function in different steps of cellulose production as revealed by genetic analysis, we conclude that BC1 modulates cellulose assembly by interacting with cellulose and affecting microfibril crystallinity.

  7. Reaction mechanisms in cellulose pyrolysis: a literature review

    Energy Technology Data Exchange (ETDEWEB)

    Molton, P.M.; Demmitt, T.F.

    1977-08-01

    A bibliographic review of 195 references is presented outlining the history of the research into the mechanisms of cellulose pyrolysis. Topics discussed are: initial product identification, mechanism of initial formation of levoglucosan, from cellulose and from related compounds, decomposition of cellulose to other compounds, formation of aromatics, pyrolysis of levoglucosan, crosslinking of cellulose, pyrolytic reactions of cellulose derivatives, and the effects of inorganic salts on the pyrolysis mechanism. (JSR)

  8. Preparation, characterisation and wetting of fluorinated cellulose surfaces

    OpenAIRE

    Aulin, Christian

    2007-01-01

    This thesis deals with the wetting by oil mixtures of two different model cellulose surfaces. The surfaces studied were a regenerated cellulose (RG) surface prepared by spin-coating, and a film consisting of polyelectrolyte multilayers (PEM) of Poly(ethyleneimine) (PEI) and a carboxymethylated Microfibrillated Cellulose (MFC). After coating or covalently modifying the cellulose surfaces with various amounts of fluorosurfactants, the fluorinated cellulose films were used to follow the spreadin...

  9. Cellulosic Bionanocomposites: A Review of Preparation, Properties and Applications

    OpenAIRE

    Alain Dufresne; Gilberto Siqueira; Julien Bras

    2010-01-01

    Cellulose is the most abundant biomass material in nature. Extracted from natural fibers, its hierarchical and multi-level organization allows different kinds of nanoscaled cellulosic fillers—called cellulose nanocrystals or microfibrillated cellulose (MFC)—to be obtained. Recently, such cellulose nanoparticles have been the focus of an exponentially increasing number of works or reviews devoted to understanding such materials and their applications. Major studies over the last decades have s...

  10. Spray-Dried Cellulose Nanofibers as Novel Tablet Excipient

    OpenAIRE

    Kolakovic, Ruzica; Peltonen, Leena; Laaksonen, Timo; Putkisto, Kaisa; Laukkanen, Antti; Hirvonen, Jouni

    2011-01-01

    The purpose of this study was to evaluate the potential of cellulose nanofibers (also referred as microfibrillated cellulose, nanocellulose, nanofibrillated, or nanofibrillar cellulose) as novel tabletting material. For this purpose, physical and mechanical properties of spray-dried cellulose nanofibers (CNF) were examined, and results were compared to those of two commercial grades of microcrystalline cellulose (MCC), Avicel PH101 and Avicel PH102, which are the most commonly and widely used...

  11. Hydrolytic and Oxidative Mechanisms Involved in Cellulose Degradation

    OpenAIRE

    Nutt, Anu

    2006-01-01

    The enzymatic degradation of cellulose is an important process in nature. This thesis has focused on the degradation of cellulose by enzymes from two cellulose-degrading fungi, Hypocrea jecorina and Phanerochaete chrysosporium, including both the action of the individual enzymes and their synergistic interplay. The end-preference of cellobiohydrolases on crystalline cellulose was studied. Cellobiohydrolases belonging to glycosyl hydrolase (GH) family 7 were found to hydrolyse cellulose proce...

  12. Role of bacterial cellulose fibrils in Agrobacterium tumefaciens infection.

    OpenAIRE

    Matthysse, A G

    1983-01-01

    During the attachment of Agrobacterium tumefaciens to carrot tissue culture cells, the bacteria synthesize cellulose fibrils. We examined the role of these cellulose fibrils in the attachment process by determining the properties of bacterial mutants unable to synthesize cellulose. Such cellulose-minus bacteria attached to the carrot cell surface, but, in contrast to the parent strain, with which larger clusters of bacteria were seen on the plant cell, cellulose-minus mutant bacteria were att...

  13. Fabrication of polyaniline/carboxymethyl cellulose/cellulose nanofibrous mats and their biosensing application

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • PANI nanorods have been grown onto the surface of CMC/cellulose nanofibers for the fabrication of biosensor substrate material. • The proposed laccase biosensor exhibited a low detection limit and high sensitivity in the detection of catechol. • Hierarchical PANI/CMC/cellulose nanofibers are the promising material in the design of high-efficient biosensors. - Abstract: We report a facile approach to synthesizing and immobilizing polyaniline nanorods onto carboxymethyl cellulose (CMC)-modified cellulose nanofibers for their biosensing application. Firstly, the hierarchical PANI/CMC/cellulose nanofibers were fabricated by in situ polymerization of aniline on the CMC-modified cellulose nanofiber. Subsequently, the PANI/CMC/cellulose nanofibrous mat modified with laccase (Lac) was used as biosensor substrate material for the detection of catechol. PANI/CMC/cellulose nanofibers with highly conductive and three dimensional nanostructure were characterized by scanning electron microscopy (SEM), transmission electron microscope (TEM), Fourier transform infrared spectra (FT-IR), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Under optimum conditions, the Lac/PANI/CMC/cellulose/glassy carbon electrode (GCE) exhibited a fast response time (within 8 s), a linear response range from 0.497 μM to 2.27 mM with a high sensitivity and low detection limit of 0.374 μM (3σ). The developed biosensor also displayed good repeatability, reproducibility as well as selectivity. The results indicated that the composite mat has potential application in enzyme biosensors

  14. Fabrication of polyaniline/carboxymethyl cellulose/cellulose nanofibrous mats and their biosensing application

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Jiapeng, E-mail: firgexiao@sina.cn; Pang, Zengyuan, E-mail: pangzengyuan1212@163.com; Yang, Jie, E-mail: young1993@126.com; Huang, Fenglin, E-mail: flhuang@jiangnan.edu.cn; Cai, Yibing, E-mail: yibingcai@jiangnan.edu.cn; Wei, Qufu, E-mail: qfwei@jiangnan.edu.cn

    2015-09-15

    Graphical abstract: - Highlights: • PANI nanorods have been grown onto the surface of CMC/cellulose nanofibers for the fabrication of biosensor substrate material. • The proposed laccase biosensor exhibited a low detection limit and high sensitivity in the detection of catechol. • Hierarchical PANI/CMC/cellulose nanofibers are the promising material in the design of high-efficient biosensors. - Abstract: We report a facile approach to synthesizing and immobilizing polyaniline nanorods onto carboxymethyl cellulose (CMC)-modified cellulose nanofibers for their biosensing application. Firstly, the hierarchical PANI/CMC/cellulose nanofibers were fabricated by in situ polymerization of aniline on the CMC-modified cellulose nanofiber. Subsequently, the PANI/CMC/cellulose nanofibrous mat modified with laccase (Lac) was used as biosensor substrate material for the detection of catechol. PANI/CMC/cellulose nanofibers with highly conductive and three dimensional nanostructure were characterized by scanning electron microscopy (SEM), transmission electron microscope (TEM), Fourier transform infrared spectra (FT-IR), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Under optimum conditions, the Lac/PANI/CMC/cellulose/glassy carbon electrode (GCE) exhibited a fast response time (within 8 s), a linear response range from 0.497 μM to 2.27 mM with a high sensitivity and low detection limit of 0.374 μM (3σ). The developed biosensor also displayed good repeatability, reproducibility as well as selectivity. The results indicated that the composite mat has potential application in enzyme biosensors.

  15. Mutation in the xpsD gene of Xanthomonas axonopodis pv. citri affects cellulose degradation and virulence

    Directory of Open Access Journals (Sweden)

    Juliana Cristina Baptista

    2010-01-01

    Full Text Available The Gram-negative bacterium Xanthomonas axonopodis pv. citri, the causal agent of citrus canker, is a major threat to the citrus industry worldwide. Although this is a leaf spot pathogen, it bears genes highly related to degradation of plant cell walls, which are typically found in plant pathogens that cause symptoms of tissue maceration. Little is known on Xac capacity to cause disease and hydrolyze cellulose. We investigated the contribution of various open reading frames on degradation of a cellulose compound by means of a global mutational assay to selectively screen for a defect in carboxymethyl cellulase (CMCase secretion in X. axonopodis pv. citri. Screening on CMC agar revealed one mutant clone defective in extracellular glycanase activity, out of nearly 3,000 clones. The insertion was located in the xpsD gene, a component of the type II secretion system (T2SS showing an influence in the ability of Xac to colonize tissues and hydrolyze cellulose. In summary, these data show for the first time, that X. axonopodis pv. citri is capable of hydrolyzing cellulose in a T2SS-dependent process. Furthermore, it was demonstrated that the ability to degrade cellulose contributes to the infection process as a whole.

  16. A pilot study for development of a novel tool for clinical decision making to identify fallers among ophthalmic patients

    OpenAIRE

    Melillo, P; Orrico, A; Attanasio, M.; Rossi, S.; Pecchia, L; Chirico, F.; F. Testa; Simonelli, F.

    2015-01-01

    Background Falls in the elderly is a major problem. Although falls have a multifactorial etiology, a commonly cited cause of falls in older people is poor vision. This study proposes a method to discriminate fallers and non-fallers among ophthalmic patients, based on data-mining algorithms applied to health and socio-demographic information. Methods A group of 150 subjects aged 55 years and older, recruited at the Eye Clinic of the Second University of Naples, underwent a baseline ophthalmic ...

  17. Current practices of diagnostic techniques requir- ing the use of ophthalmic drugs among KwaZulu- Natal optometrists*

    OpenAIRE

    K. P. Mashige; K. S. Naidoo

    2009-01-01

    In anendeavour to improve the quality of optometric eye care services in South Africa, the scope of practice was expanded to include the use of ocular diagnostic procedures such as goniosco-py that require the use of ophthalmic drugs. The purpose of this study was to assess the practices of specific diagnostic techniques (contact tonometry, 78 D/90 D lens fundus examination, binocular indirect ophthalmoscopy and gonioscopy) requiring the use of ophthalmic drugs among optometrists in KwaZulu-N...

  18. Comparative effiacy of marine Streptomyces formulation versus ciproflxacin ophthalmic solution for treating Staphylococcus aureus-induced conjunctivitis in animal model

    OpenAIRE

    Femina Wahaab; Kalidass Subramaniam; Morris Jawahar

    2016-01-01

    Objective: To report the efficacy of marine actinomycetes in controlling Staphylococcus aureus (S. aureus)-induced conjunctivitis in experimental rabbit. Methods: The ethyl acetate extracts of the best isolates of actinomycetes from the soil samples of Rameswaram coastal regions, Tamil Nadu, India, were concentrated and re-constituted in buffer and used as actinomycetes ophthalmic suspension in this study. The anti-inflammatory efficacy of actinomycetes ophthalmic suspension wa...

  19. Accessibility of ophthalmic healthcare for residents of an offshore island—an example of integrated delivery system

    OpenAIRE

    Chen, Li-Ju; Chang, Yun-Jau; Shieh, Chun-Fu; Yu, Jy-Haw; Yang, Ming-Chin

    2016-01-01

    Background To assess the utilization of and satisfaction with ophthalmic healthcare provided by integrated delivery system (IDS) since 2000 and vision-related quality of life (VRQoL) for residents of an offshore island of Taiwan. Methods Facilitators interviewed residents (age ≥ 50 years) with the 25-item National Eye Institute Visual Function Questionnaire (NEI-VFQ-25) for VRQoL and a questionnaire on clinical information, ophthalmic care utilization and satisfaction. Results A total of 841 ...

  20. Protective Effect of Tea Polyphenol Ophthalmic Gel on Lens Epithelial Cells in Rabbits with Silicone Oil Tamponade after Vitrectomy

    OpenAIRE

    Xianzhen Ma; Dadong Guo; Hongsheng Bi; Xiaofeng Xie; Junguo Guo; Yan Cui

    2014-01-01

    Purpose. The aim of this study was to investigate the effect of tea polyphenols (TP) ophthalmic gel on lens epithelial cells (LECs) in rabbits with silicone oil tamponade after vitrectomy. Methods. In this study, unilateral vitrectomy with silicone oil tamponade was performed using 2-month-old New Zealand white rabbits (n = 72); meanwhile, age-matched nonoperated rabbits (n = 18) were used as controls. The TP ophthalmic gel was administered topically in the surgical eyes till they were sacrif...

  1. HB+ inserted into the CMS Solenoid

    CERN Multimedia

    Tejinder S. Virdee, CERN

    2006-01-01

    The first half of the barrel hadron calorimeter (HB+) has been inserted into the superconducting solenoid of CMS, in preparation for the magnet test and cosmic challenge. The operation went smoothly, lasting a couple of days.

  2. Rapid saccharification for production of cellulosic biofuels.

    Science.gov (United States)

    Lee, Dae-Seok; Wi, Seung Gon; Lee, Soo Jung; Lee, Yoon-Gyo; Kim, Yeong-Suk; Bae, Hyeun-Jong

    2014-04-01

    The economical production of biofuels is hindered by the recalcitrance of lignocellulose to processing, causing high consumption of processing enzymes and impeding hydrolysis of pretreated lignocellulosic biomass. We determined the major rate-limiting factor in the hydrolysis of popping pre-treated rice straw (PPRS) by examining cellulase adsorption to lignin and cellulose, amorphogenesis of PPRS, and re-hydrolysis. Based on the results, equivalence between enzyme loading and the open structural area of cellulose was required to significantly increase productive adsorption of cellulase and to accelerate enzymatic saccharification of PPRS. Amorphogenesis of PPRS by phosphoric acid treatment to expand open structural area of the cellulose fibers resulted in twofold higher cellulase adsorption and increased the yield of the first re-hydrolysis step from 13% to 46%. The total yield from PPRS was increased to 84% after 3h. These results provide evidence that cellulose structure is one of major effects on the enzymatic hydrolysis. PMID:24607460

  3. Carboxymethylation of Cellulose by Microwave irradiation

    Institute of Scientific and Technical Information of China (English)

    YE; Jun

    2001-01-01

    Cellulose may be readily converted into ethers involving primary and secondary alcohol groups in each monomer unit and the glycosidic bonds. However, these reactions are rather more complicated than with simple substances, because the stereochemistry of the cellulose molecule is such that the vast majority of its hydroxyl groups form intra-chain hydrogen bonds or inter-chain hydrogen bonds with contiguous molecules. Carboxymethylcellulose (CMC) has played an important part in the commercial uses of cellulose derivatives. CMC becomes alkali and water soluble. The polarity can, in fact, be increased by introduction of ionizing groups, ie carboxymethyl group. CMC is generally produced by the reaction of alkali cellulose with chloroacetic acid.……

  4. Cellulosic ethanol is ready to go

    Energy Technology Data Exchange (ETDEWEB)

    Burke, M. [SunOpta BioProcess Group, Brampton, ON (Canada)

    2006-07-01

    A corporate overview of the SunOpta organization was presented. The organization includes three divisions, notably organic food, industrial minerals, and a bioprocess group. It is a Canadian organization that has experienced over 60 per cent growth per year since 1999. The presentation provided a history of the bioprocess group from 1973 to 2003. The presentation also illustrated the biomass process from wood, straw or corn stover to cellulosic ethanol and acetone and butanol. Several images were presented. The production of xylitol from oat hulls and birch and from ryegrass straw to linerboard was also illustrated. Last, the presentation illustrated the biomass production of cellulose, hemicellulose and lignin extraction as well as the ammonia pretreatment of cellulosics. The presentation also listed several current and future developments such as an expansion plan and implementation of cellulosic ethanol. Economic success was defined as requiring proximity to market; high percentage concentration to distillation; and co-located within existing infrastructure. figs.

  5. Stimuli-sensitive hydrogels: A novel ophthalmic drug delivery system

    Directory of Open Access Journals (Sweden)

    Singh Vinod

    2010-01-01

    Full Text Available Background: Stimuli-sensitive hydrogels are three-dimensional, hydrophilic, polymeric networks capable of imbibing large amounts of water or biological fluids on stimulation, such as pH, temperature and ionic change. Aim: To develop hydrogels that are sensitive to stimuli, i.e. pH, in the cul-de-sac of the eye for providing a prolonged effect and increased bioavailability with reduction in frequency of administration. Materials and Methods: Hydrogels were formulated by using timolol maleate as the model drug, polyacrylic acid as the gelling agents, hydroxyl ethyl cellulose as the viscolizer and sodium chloride as the isotonic agent. Stirring of ingredients in pH 4 phosphate buffer at high speed was carried out. The dynamic dialysis technique was used for drug release studies. In vivo study for reduction in intraocular pressure was carried out by using albino rabbits. Statistical Analysis: Drug release studies data were used for statistical analysis in first-order plots, Higuchi plots and Peppas exponential plots. Student t-test was performed for in vivo study. Results: Viscosity of the hydrogel increases from 3.84 cps to 9.54 cps due to change in pH 4 to pH 7.4. The slope value of the Peppas equation was found to be 0.3081, 0.3743 and 0.2964. Up to 80% of drug was released in an 8 h drug release study. Sterile hydrogels with no ocular irritation were obtained. Conclusions: Hydrogels show increase in viscosity due to change in pH. Hydrogels were therapeutically effacious, stable, non-irritant and showed Fickian diffusion. In vivo results clearly show a prolonged reduction in intraocular pressure, which was helpful for reduction in the frequency of administration.

  6. An Unusual Complication of Suprapubic Catheter Insertion

    Directory of Open Access Journals (Sweden)

    Krishnan Ananthakrishnan

    2006-01-01

    Full Text Available A patient who had a small bowel mesentery perforation following insertion of a suprapubic catheter (SPC is described. He had no bowel complaints immediately following the procedure, but presented 10 weeks later with insidious onset bowel obstruction due to the kink caused by the catheter. This complication occurred despite cystoscopy control and adequate bladder distension prior to the procedure. This isolated case illustrates the fact that regardless of the ease and frequency of SPC insertion, complications do occur.

  7. Cellulose whisker/epoxy resin nanocomposites

    OpenAIRE

    Tang, Liming; Weder, Christoph

    2010-01-01

    New nanocomposites composed of cellulose nanofibers or “whiskers” and an epoxy resin were prepared. Cellulose whiskers with aspect ratios of ∼10 and ∼84 were isolated from cotton and sea animals called tunicates, respectively. Suspensions of these whiskers in dimethylformamide were combined with an oligomeric difunctional diglycidyl ether of bisphenol A with an epoxide equivalent weight of 185−192 and a diethyl toluenediamine-based curing agent. Thin films were produced by casting these mixtu...

  8. Nanopores Structure in Electrospun Bacterial Cellulose

    OpenAIRE

    Pierre Basmaji; Gabriel Molina de Olyveira; Ligia Maria Manzine Costa; Lauro Xavier Filho

    2011-01-01

    Bacterial cellulose (BC) has established to be a remarkably versatile biomaterial and can be used in wide variety of applied scientific endeavours, especially for medical devices, lately, bacterial cellulose mats are used in the treatment of skin conditions such as burns and ulcers, because of the morphology of fibrous biopolymers serving as a support for cell proliferation, its pores allow gas exchange between the organism and the environment. Moreover, the nanostructure and morphological si...

  9. Cellulose composite structures – by design

    OpenAIRE

    Winkworth-Smith, Charles G.

    2015-01-01

    The aim of the work presented in this thesis was to investigate different mechanical and chemical pre-treatments which can dramatically change the properties of native cellulose and add alternative routes to structure formation. Ball milled cellulose, which had a reduced crystallinity, degree of polymerisation and degradation temperature, was rehydrated in excess water resulting in recrystallisation. Fully amorphous samples recrystallised to the more thermodynamically stable type II polymorph...

  10. Nanosized Cellulose Fibrils as Stabilizer of Emulsions

    OpenAIRE

    Xhanari, Klodian

    2011-01-01

    Pickering emulsions have been a subject of research for many years due to their practical applications not only in everyday life products but also in industry. The stability of these emulsions is due to the irreversible adsorption of colloid particles at the oil/water interface which prevents droplet coalescence. Cellulose materials are among the different types of particles used as stabilizers. Most of the studies report the use of native cellulose as stabilizer of oil-in-water emulsions due...

  11. Production of Cellulosic Polymers from Agricultural Wastes

    OpenAIRE

    Israel, A. U.; I. B. Obot; Umoren, S. A.; Mkpenie, V.; Asuquo, J. E.

    2008-01-01

    Cellulosic polymers namely cellulose, di-and triacetate were produced from fourteen agricultural wastes; Branch and fiber after oil extraction from oil palm (Elais guineensis), raffia, piassava, bamboo pulp, bamboo bark from raphia palm (Raphia hookeri), stem and cob of maize plant (Zea mays), fruit fiber from coconut fruit (Cocos nucifera), sawdusts from cotton tree (Cossypium hirsutum), pear wood (Manilkara obovata), stem of Southern gamba green (Andropogon tectorus), sugarcane baggase (Sac...

  12. Strength of inserts in titanium alloy machining

    Science.gov (United States)

    Kozlov, V.; Huang, Z.; Zhang, J.

    2016-04-01

    In this paper, a stressed state of a non-worn cutting wedge in a machined titanium alloy (Ti6Al2Mo2Cr) is analyzed. The distribution of contact loads on the face of a cutting tool was obtained experimentally with the use of a ‘split cutting tool’. Calculation of internal stresses in the indexable insert made from cemented carbide (WC8Co) was carried out with the help of ANSYS 14.0 software. Investigations showed that a small thickness of the cutting insert leads to extremely high compressive stresses near the cutting edge, stresses that exceed the ultimate compressive strength of cemented carbide. The face and the base of the insert experience high tensile stresses, which approach the ultimate tensile strength of cemented carbide and increase a probability of cutting insert destruction. If the thickness of the cutting insert is bigger than 5 mm, compressive stresses near the cutting edge decrease, and tensile stresses on the face and base decrease to zero. The dependences of the greatest normal and tangential stresses on thickness of the cutting insert were found. Abbreviation and symbols: m/s - meter per second (cutting speed v); mm/r - millimeter per revolution (feed rate f); MPa - mega Pascal (dimension of specific contact loads and stresses); γ - rake angle of the cutting tool [°] α - clearance angle of the sharp cutting tool [°].

  13. Z-2 Threaded Insert Design and Testing

    Science.gov (United States)

    Ross, Amy; Rhodes, Richard; Jones, Robert J.; Graziosi, David; Ferl, Jinny; Sweeny, Mitch; Scarborough, Stephen

    2016-01-01

    NASA's Z-2 prototype space suit contains several components fabricated from an advanced hybrid composite laminate consisting of IM10 carbon fiber and fiber glass. One requirement was to have removable, replaceable helicoil inserts to which other suit components would be fastened. An approach utilizing bonded in inserts with helicoils inside of them was implemented. During initial assembly, cracking sounds were heard followed by the lifting of one of the blind inserts out of its hole when the screws were torqued. A failure investigation was initiated to understand the mechanism of the failure. Ultimately, it was determined that the pre-tension caused by torqueing the fasteners is a much larger force than induced from the pressure loads of the suit which was not considered in the insert design. Bolt tension is determined by dividing the torque on the screw by a k value multiplied by the thread diameter of the bolt. The k value is a factor that accounts for friction in the system. A common value used for k for a non-lubricated screw is 0.2. The k value can go down by as much as 0.1 if the screw is lubricated which means for the same torque, a much larger tension could be placed on the bolt and insert. This paper summarizes the failure investigation that was performed to identify the root cause of the suit failure and details how the insert design was modified to resist a higher pull out tension.

  14. Oxidative-stress detoxification and signalling in cyanobacteria: the crucial glutathione synthesis pathway supports the production of ergothioneine and ophthalmate.

    Science.gov (United States)

    Narainsamy, Kinsley; Farci, Sandrine; Braun, Emilie; Junot, Christophe; Cassier-Chauvat, Corinne; Chauvat, Franck

    2016-04-01

    Using genetics and metabolomics we investigated the synthesis (gshA and gshB genes) and catabolism (ggt) of the conserved antioxidant glutathione in the model cyanobacterium Synechocystis PCC6803. These three genes are crucial to Synechocystis, in agreement with the proposed invention of glutathione by ancient cyanobacteria to protect themselves against the toxicity of oxygen they produced through photosynthesis. Consistent with their indispensability, gshA and gshB also operate in the production of another antioxidant, ergothioneine, as well as of the glutathione analogues ophthalmate and norophthalmate. Furthermore, we show that glutathione, ophthalmate and norophthalmate are accumulated in cells stressed by glucose, and that the two glutathione-dependent glyoxalase enzymes operate in the protection against glucose and its catabolite methylglyoxal. These findings are interesting because ophthalmate and norophthalmate were observed only in mammals so far, where ophthalmate is regarded as a biomarker of glutathione depletion. Instead, our data suggest that ophthalmate and norophthalmate are stress-induced markers of cysteine depletion triggered by its accelerated incorporation into glutathione, to face its increased demand for detoxification purposes. Hence, Synechocystis is an attractive model for the analysis of the role of glutathione, ergothioneine, ophthalmate and norophthalmate, in signalling and detoxification of oxidants and metabolic by-products. PMID:26713511

  15. Utilization of biocatalysts in cellulose waste minimization

    Energy Technology Data Exchange (ETDEWEB)

    Woodward, J.; Evans, B.R.

    1996-09-01

    Cellulose, a polymer of glucose, is the principal component of biomass and, therefore, a major source of waste that is either buried or burned. Examples of biomass waste include agricultural crop residues, forestry products, and municipal wastes. Recycling of this waste is important for energy conservation as well as waste minimization and there is some probability that in the future biomass could become a major energy source and replace fossil fuels that are currently used for fuels and chemicals production. It has been estimated that in the United States, between 100-450 million dry tons of agricultural waste are produced annually, approximately 6 million dry tons of animal waste, and of the 190 million tons of municipal solid waste (MSW) generated annually, approximately two-thirds is cellulosic in nature and over one-third is paper waste. Interestingly, more than 70% of MSW is landfilled or burned, however landfill space is becoming increasingly scarce. On a smaller scale, important cellulosic products such as cellulose acetate also present waste problems; an estimated 43 thousand tons of cellulose ester waste are generated annually in the United States. Biocatalysts could be used in cellulose waste minimization and this chapter describes their characteristics and potential in bioconversion and bioremediation processes.

  16. Biohydrogen, bioelectricity and bioalcohols from cellulosic materials

    Energy Technology Data Exchange (ETDEWEB)

    Nissila, M.

    2013-03-01

    The demand for renewable energy is increasing due to increasing energy demand and global warming associated with increasing use of fossil fuels. Renewable energy can be derived from biological production of energy carriers from cellulosic biomass. These biochemical processes include biomass fermentation to hydrogen, methane and alcohols, and bioelectricity production in microbial fuel cells (MFCs). The objective of this study was to investigate the production of different energy carriers (hydrogen, methane, ethanol, butanol, bioelectricity) through biochemical processes. Hydrogen production potential of a hot spring enrichment culture from different sugars was determined, and hydrogen was produced continuously from xylose. Cellulolytic and hydrogenic cultures were enriched on cellulose, cellulosic pulp materials, and on silage at different process conditions. The enrichment cultures were further characterized. The effect of acid pretreatment on hydrogen production from pulp materials was studied and compared to direct pulp fermentation to hydrogen. Electricity and alcohol(s) were simultaneously produced from xylose in MFCs and the exoelectrogenic and alcohologenic enrichment cultures were characterized. In the end, the energy yields obtained from different biochemical processes were determined and compared. In this study, cultures carrying out simultaneous cellulose hydrolysis and hydrogen fermentation were enriched from different sources at different operational conditions. These cultures were successfully utilized for cellulose to hydrogen fermentation in batch systems. Based on these results further research should be conducted on continuous hydrogen production from cellulosic materials.

  17. Nanofibrillar cellulose films for controlled drug delivery.

    Science.gov (United States)

    Kolakovic, Ruzica; Peltonen, Leena; Laukkanen, Antti; Hirvonen, Jouni; Laaksonen, Timo

    2012-10-01

    Nanofibrillar cellulose (NFC) (also referred to as cellulose nanofibers, nanocellulose, microfibrillated, or nanofibrillated cellulose) has gotten recent and wide attention in various research areas. Here, we report the application of nanofibrillar cellulose as a matrix-former material for long-lasting (up to three months) sustained drug delivery. Film-like matrix systems with drug loadings between 20% and 40% were produced by a filtration method. This simple production method had an entrapment efficacy>90% and offers a possibility for the film thickness adjustment as well as applicability in the incorporation of heat sensitive compounds. The films had excellent mechanical properties suitable for easy handling and shape tailoring of the drug release systems. They were characterized in terms of the internal morphology, and the physical state of the encapsulated drug. The drug release was assessed by dissolution tests, and suitable mathematical models were used to explain the releasing kinetics. The drug release was sustained for a three month period with very close to zero-order kinetics. It is assumed that the nanofibrillar cellulose film sustains the drug release by forming a tight fiber network around the incorporated drug entities. The results indicate that the nanofibrillar cellulose is a highly promising new material for sustained release drug delivery applications. PMID:22750440

  18. Cellulose fractionation with IONCELL-P.

    Science.gov (United States)

    Stepan, A M; Monshizadeh, A; Hummel, M; Roselli, A; Sixta, H

    2016-10-01

    IONCELL-P is a solvent fractionation process, which can separate pulps almost quantitatively into pure cellulose and hemicellulose fractions using IL-water mixtures. In this work the role of the molecular weight of cellulose on its solubility in ionic liquid-water mixtures is studied. The aim of this study was to understand and identify the determining factors of this IONCELL-P fractionation. Cotton linters (CL) served as model cellulose substrate and was degraded by ozone treatment to adjust the molecular weight to that of hemicelluloses and low molar mass cellulose in commercial pulps. The ozone treated CLs were subjected to the IONCELL-P process using 1-ethyl-3-methylimidazolium acetate ([emim][OAc]) and water mixtures with a water content between 13.5 and 19wt%. Based on the molar mass distributions of dissolved and undissolved cellulose the effect of the molecular weight of cellulose in IL-water mixture appears to be a key factor in the fractionation process. PMID:27312618

  19. Isolation of cellulose microfibrils - An enzymatic approach

    Directory of Open Access Journals (Sweden)

    Sain, M.

    2006-11-01

    Full Text Available Isolation methods and applications of cellulose microfibrils are expanding rapidly due to environmental benefits and specific strength properties, especially in bio-composite science. In this research, we have success-fully developed and explored a novel bio-pretreatment for wood fibre that can substantially improve the microfibril yield, in comparison to current techniques used to isolate cellulose microfibrils. Microfibrils currently are isolated in the laboratory through a combination of high shear refining and cryocrushing. A high energy requirement of these procedures is hampering momentum in the direction of microfibril isolation on a sufficiently large scale to suit potential applications. Any attempt to loosen up the microfibrils by either complete or partial destruction of the hydrogen bonds before the mechanical process would be a step forward in the quest for economical isolation of cellulose microfibrils. Bleached kraft pulp was treated with OS1, a fungus isolated from Dutch Elm trees infected with Dutch elm disease, under different treatment conditions. The percentage yield of cellulose microfibrils, based on their diameter, showed a significant shift towards a lower diameter range after the high shear refining, compared to the yield of cellulose microfibrils from untreated fibres. The overall yield of cellulose microfibrils from the treated fibres did not show any sizeable decrease.

  20. Responses of different dosemeters in beta dosimetry of 106Ru/106Rh ophthalmic applicators

    International Nuclear Information System (INIS)

    This work presents the TL response of three kinds of dosimeters from different manufacturing characteristics under irradiation of 106 Ru / 106 Rh sealed sources used in ophthalmic brachytherapy. They are: Ca SO4:Dy + teflon (D- Ca SO4:Dy -0,4), LiF:Mg, Ti (TLD-100) and Ca SO4:Dy (TLD-900). Some of reports accepted by scientific community (NCS report 14 e ICRU report 72) as reference in the quality control of beta applicators dosimetry recommend that the absorbed dose standard uncertainties can be kept below 20%. The TLD Ca SO4:Dy + teflon presented proper sensibility and high precision comparing with the others. Considering the similar dimensions of ophthalmic tumors and aside critical structures it is relevant to reduce undesirable effects due to the irradiation of these structures. Therefore, the quality control in the beta dosimetry using this kind of source is a constant challenge. (author)

  1. Pulse-to-pulse interaction analysis and parameter optimization for future-generation ophthalmic laser systems

    Science.gov (United States)

    Tinne, N.; Kaune, B.; Bleeker, S.; Lubatschowski, H.; Krüger, A.; Ripken, T.

    2014-02-01

    The immediate pulse-to-pulse interaction becomes more and more important for future-generation high-repetition rate ophthalmic laser systems. Therefore, we investigated the interaction of two laser pulses with different spatial and temporal separation by time-resolved photography. There are various different characteristic interaction mechanisms which are divided into 11 interaction scenarios. Furthermore, the parameter range has been constricted regarding the medical application; here, the efficiency was optimized to a maximum jet velocity along the scanning axis with minimum applied pulse energy as well as unwanted side effects at the same time. In conclusion, these results are of great interest for the prospective optimization of the ophthalmic surgical process with future-generation fs-lasers.

  2. Cellulose nanofibers from Curaua fibers

    International Nuclear Information System (INIS)

    Curaua is a plant from Amazon region whose leaves were used by the indians of the region to make nets, ropes, fishing wires, etc., due to their high mechanical resistance. Nowadays, some industries, mainly textile and automobile, have increased their interest on these fibers to prepare polymer composites, because their properties could be compared to composites with glass fibers. In this work, cellulose nanofibers were obtained from curaua fibers, which were submitted to alkaline treatment with a solution of NaOH 5%. Nanofibers, in watery suspension, were characterized morphologically by TEM and AFM, and they show needle like format and the ratio L/D of 14. The suspension was dried by freeze dried process, in vacuum and air circulation oven, and these nanofibers were analyzed by x-ray diffraction, presenting high crystalline index, and by thermogravimetric analysis (TGA), which showed that nanofibers have poorer thermal stability than the treated fiber, but they can reach values next to the ones of the original fibers, depending on the drying process of the suspension. (author)

  3. IN SITU GELS- A NEW TRENDS IN OPHTHALMIC DRUG DELIVERY SYSTEMS

    OpenAIRE

    Ramanjit Saini; Seema Saini; Gurpreet Singh; Dr. Angshu Banerjee

    2015-01-01

    Ophthalmic drug delivery is one of the most interesting and challenging endeavor facing the pharmaceutical scientist. The conventional ocular drug delivery systems like solutions, suspensions, and ointments show drawbacks such as increased precorneal elimination, high variability in efficiency, and blurred vision respectively so there was a need for developing advanced drug delivery system. In situ forming polymeric formulations were developed to overcome the conventional drug therapy drawbac...

  4. Persistent corneal epithelial defect responding to rebamipide ophthalmic solution in a patient with diabetes

    OpenAIRE

    Hayashi Y; Toshida H; Matsuzaki Y; Matsui A; Ohta T

    2016-01-01

    Yusuke Hayashi, Hiroshi Toshida, Yusuke Matsuzaki, Asaki Matsui, Toshihiko Ohta Department of Ophthalmology, Juntendo University Shizuoka Hospital, Izunokuni, Shizuoka, Japan Objective: Rebamipide ophthalmic suspension was developed for the treatment of dry eyes and for other corneal diseases, promoting the secretion of both mucin in tear fluid and membrane-associated mucin, increasing the number of goblet cells, and restoring the barrier function of the corneal epithelium. We report a case ...

  5. Ophthalmic Artery Obstruction and Cerebral Infarction Following Periocular Injection of Autologous Fat

    OpenAIRE

    Lee, Chang Mok; Hong, In Hwan; Park, Sung Pyo

    2011-01-01

    We report a case of ophthalmic artery obstruction combined with brain infarction following periocular autologous fat injection. The patient, a 44-year-old woman, visited our hospital for decreased visual acuity in her left eye and dysarthria one hour after receiving an autologous fat injection in the periocular area. Her best corrected visual acuity for the concerned eye was no light perception. Also, a relative afferent pupillary defect was detected in this eye. The left fundus exhibited wid...

  6. Review of moxifloxacin hydrochloride ophthalmic solution in the treatment of bacterial eye infections

    OpenAIRE

    Darlene Miller

    2008-01-01

    Darlene MillerAbrams Ocular Microbiology Laboratory, Bascom Palmer Eye Institute, Anne Bates Leach Eye Hospital, Miller School of Medicine-University of Miami, FL, USAAbstract: Moxifloxacin hydrochloride ophthalmic solution 0.5% (Vigamox®) is the ocular formulation/adaptation of moxifloxacin. Moxifloxacin is a broad spectrum 8-methoxyfluoroquinolone which terminates bacterial growth by binding to DNA gyrase (topoisomerase II) and topoisomerase IV, essential bacterial enzymes involved ...

  7. Solvent Composition is Critical for Carbodiimide Cross-Linking of Hyaluronic Acid as an Ophthalmic Biomaterial

    OpenAIRE

    Jui-Yang Lai

    2012-01-01

    Hyaluronic acid (HA) is one of the most important ophthalmic biomaterials, while also being used for tissue engineering and drug delivery. Although chemical cross-linking is an effective way to improve the material performance, it may as a consequence be detrimental to the living cells/tissues. Given that the cross-linking efficiency is mediated by the solvent composition during the chemical modification, this study aims to explore the stability and biocompatibility of carbodiimide cross-link...

  8. The management of ophthalmic involvement in blue rubber bleb nevus syndrome

    OpenAIRE

    Petek, B; Jones, RL

    2014-01-01

    Objective: Blue rubber bleb nevus syndrome is a rare vascular disease most commonly associated with venous malformations of the skin and the gastrointestinal tract. Few ophthalmic cases have been reported to date, and no clear treatment regimen exists. We describe the case of a 59-year-old man, along with a review of literature, to help in the future diagnosis and treatment of patients with the disease. Methods: This paper is an observational case report and a review of medical literature o...

  9. The management of ophthalmic involvement in blue rubber bleb nevus syndrome

    OpenAIRE

    Petek, Bradley; Jones, Robin L.

    2014-01-01

    [english] Objective: Blue rubber bleb nevus syndrome is a rare vascular disease most commonly associated with venous malformations of the skin and the gastrointestinal tract. Few ophthalmic cases have been reported to date, and no clear treatment regimen exists. We describe the case of a 59-year-old man, along with a review of literature, to help in the future diagnosis and treatment of patients with the disease. Methods: This paper is an observational case report and a review of medical lite...

  10. 103Pd versus 125I ophthalmic plaque brachytherapy: preoperative comparative radiation dosimetry for 319 uveal melanomas

    OpenAIRE

    Finger, Paul T; Zhou, Di; Kalach, Nina; Semenova, Ekaterina; Choi, Walter

    2014-01-01

    Objective This study was conducted to compare the relative, clinical intraocular dose distribution for palladium-103 (103Pd) versus iodine-125 (125I) ophthalmic plaque radiation therapy. Methods Preoperative comparative radiation dosimetry was performed to evaluate 319 consecutive uveal melanomas treated between 2006 and 2012. Results There were 68 (21.3 %) anterior (iris and/or ciliary body) and 251 (78.7 %) choroidal melanomas examined in this study. According to AJCC staging, 7th edition, ...

  11. Regulation of vascular tone in rabbit ophthalmic artery: cross talk of endogenous and exogenous gas mediators.

    Science.gov (United States)

    Salomone, Salvatore; Foresti, Roberta; Villari, Ambra; Giurdanella, Giovanni; Drago, Filippo; Bucolo, Claudio

    2014-12-15

    Nitric oxide (NO), carbon monoxide (CO) and hydrogen sulphide (H2S) modulate vascular tone. In view of their therapeutic potential for ocular diseases, we examined the effect of exogenous CO and H2S on tone of isolated rabbit ophthalmic artery and their interaction with endogenous and exogenous NO. Ophthalmic artery segments mounted on a wire myograph were challenged with cumulative concentrations of phenylephrine (PE) in the presence or absence of NG-nitro-L-arginine (LNNA) to inhibit production of NO, the CO-releasing molecules CORMs or the H2S-donor GYY4137. The maximal vasoconstriction elicited by PE reached 20-30% of that induced by KCl but was dramatically increased by incubation with LNNA. GYY4137 significantly raised PE-mediated vasoconstriction, but it did not change the response to PE in the presence of LNNA or the relaxation to sodium nitroprusside (SNP). CORMs concentration-dependently inhibited PE-induced constriction, an effect that was synergistic with endogenous NO (reduced by LNNA), but insensitive to blockade of guanylyl cyclase by 1H-[1,2,4]oxadiazolo[4,3,-α]quinoxalin-1-one (ODQ). In vascular tissues cyclic GMP (cGMP) levels seemed reduced by GYY4137 (not significantly), but were not changed by CORM. These data indicate that CO is able per se to relax isolated ophthalmic artery and to synergize with NO, while H2S counteracts the effect of endogenous NO. CO does not stimulate cGMP production in our system, while H2S may reduce cGMP production stimulated by endogenous NO. These findings provide new insights into the complexities of gas interactions in the control of ophthalmic vascular tone, highlighting potential pharmacological targets for ocular diseases. PMID:25451691

  12. Evaluation of the ophthalmic and dermal irritability of the OLEOMASAJE formulation

    OpenAIRE

    Maritza F. Díaz; Kendra García; Rosa I. Meneau; Yaíma Sánchez; Gastón García

    2015-01-01

    Context: Ozonized vegetable oils present germicidal effects which can be used as active principle in different cosmetological compositions. The thematic about of the corporal massage advantage have been very treatment by aesthetics, dermatologic and consumers. OLEOMASAJE formulation content ozonized sunflower oil OLEOZON as active principle active which present moisturizer and conditioner effects. Aims: To determine the possible dermal and ophthalmic irritability effects of the OLEOMASAJE...

  13. Effectiveness and relevant factors of 2 % rebamipide ophthalmic suspension treatment in dry eye

    OpenAIRE

    UEDA, Kaori; Matsumiya, Wataru; Otsuka, Keiko; Maeda, Yoshifumi; Nagai, Takayuki; Nakamura, Makoto

    2015-01-01

    Background Rebamipide with mucin secretagogue activity was recently approved for the treatment of dry eye. The efficacy and safety in the treatment of rebamipide were shown in two pivotal clinical trials. It was the aim of this study to evaluate the effect of 2 % rebamipide ophthalmic suspension in patients with dry eye and analyze relevant factors for favorable effects of rebamipide in clinical practice. Methods This was a retrospective cohort study of 48 eyes from 24 patients with dry eye t...

  14. 4D microscope-integrated OCT improves accuracy of ophthalmic surgical maneuvers

    Science.gov (United States)

    Carrasco-Zevallos, Oscar; Keller, Brenton; Viehland, Christian; Shen, Liangbo; Todorich, Bozho; Shieh, Christine; Kuo, Anthony; Toth, Cynthia; Izatt, Joseph A.

    2016-03-01

    Ophthalmic surgeons manipulate micron-scale tissues using stereopsis through an operating microscope and instrument shadowing for depth perception. While ophthalmic microsurgery has benefitted from rapid advances in instrumentation and techniques, the basic principles of the stereo operating microscope have not changed since the 1930's. Optical Coherence Tomography (OCT) has revolutionized ophthalmic imaging and is now the gold standard for preoperative and postoperative evaluation of most retinal and many corneal procedures. We and others have developed initial microscope-integrated OCT (MIOCT) systems for concurrent OCT and operating microscope imaging, but these are limited to 2D real-time imaging and require offline post-processing for 3D rendering and visualization. Our previously presented 4D MIOCT system can record and display the 3D surgical field stereoscopically through the microscope oculars using a dual-channel heads-up display (HUD) at up to 10 micron-scale volumes per second. In this work, we show that 4D MIOCT guidance improves the accuracy of depth-based microsurgical maneuvers (with statistical significance) in mock surgery trials in a wet lab environment. Additionally, 4D MIOCT was successfully performed in 38/45 (84%) posterior and 14/14 (100%) anterior eye human surgeries, and revealed previously unrecognized lesions that were invisible through the operating microscope. These lesions, such as residual and potentially damaging retinal deformation during pathologic membrane peeling, were visualized in real-time by the surgeon. Our integrated system provides an enhanced 4D surgical visualization platform that can improve current ophthalmic surgical practice and may help develop and refine future microsurgical techniques.

  15. Surface tension examination of various liquid oral, nasal, and ophthalmic dosage forms

    OpenAIRE

    Han, Kimberly; Woghiren, Osakpolor E.; Priefer, Ronny

    2016-01-01

    Surface tension at the surface-to-air interface is a physico-chemical property of liquid pharmaceutical formulations that are often overlooked. To determine if a trend between surface tension and route of administration exists, a suite of oral, nasal, and ophthalmic drug formulations were analyzed. The surface tension at the surface-to-air interface of the oral formulations studied were in or above the range of the surface tension of gastric, duodenum, and jejunum fluids. The range of surface...

  16. Impact of the Topical Ophthalmic Corticosteroid Loteprednol Etabonate on Intraocular Pressure

    OpenAIRE

    Sheppard, John D.; Timothy L Comstock; Cavet, Megan E.

    2016-01-01

    Corticosteroids are a mainstay therapeutic option for the treatment of ocular inflammation. However, safety remains a concern for clinicians, particularly with long-term use. Though highly effective at suppressing inflammatory and allergic responses, topical ophthalmic corticosteroids carry an inherent risk of side effects, including elevated intraocular pressure (IOP), a risk factor for the development of glaucoma. The corticosteroid loteprednol etabonate (LE) contains an ester rather than a...

  17. Brachytherapy of ocular melanoma : physical and dosimetric aspects of 125I ophthalmic plaques

    International Nuclear Information System (INIS)

    Off-axis absorbed dose distribution of ophthalmic plaques is a useful parameter for the explanation of some observed biological effects. From a specific dosimetric software, developed in our brachytherapy department, and from our measurements around 125I eye plaque, we studied the dose distribution effects on the spread of activities inside the plaques. After analysis of experimental data, we observed also that the dose distribution in the penumbra area may be described easily with decrement lines. (author). 17 refs., 9 figs

  18. Critical appraisal of ophthalmic ketorolac in treatment of pain and inflammation following cataract surgery

    OpenAIRE

    Reddy RK; Kim SJ

    2011-01-01

    Rahul Reddy, Stephen Jae KimDepartment of Ophthalmology, Vanderbilt University, Nashville, TN, USABackground: The purpose of this review was to provide a critical appraisal of the literature supporting the efficacy of ophthalmic ketorolac (Acuvail®) in the treatment of pain and inflammation after cataract surgery.Methods: Literature search and expert opinion of the authors.Results: Recent studies indicate greater intraocular drug levels in the anterior chamber and iris-ciliary body af...

  19. Ophthalmic survey of a diabetic clinic: II. Requirements for treatment of retinopathy.

    OpenAIRE

    Grey, R H; Morris, A.

    1986-01-01

    The eyes of 658 patients attending a district general hospital diabetic clinic were examined for retinopathy requiring treatment by photocoagulation or vitreoretinal surgery. Although the majority of patients with serious retinopathy were already under ophthalmic supervision, 39 cases (52 eyes) were found which required treatment. Eighty eyes had had previous photocoagulation, and treatment was recommended for maculopathy in 40 eyes, proliferative retinopathy in seven eyes, and combined macul...

  20. Degradation of γ-irradiated cellulose by the accumulating culture of a cellulose bacterium

    International Nuclear Information System (INIS)

    Possibility of degradation of γ-irradiated cellulose by the accumulating culture of an anaerobic cellulose bacterium has been investigated. Cellulose irradiation by γ-quanta (Co60) has been carried out using the RKh-30 device with 35.9 Gy/min dose rate. Radiation monitoring has been carried out by the standard ferrosulfate method. Samples have been irradiated in dry state or when water presenting with MGy. It is detected that the accumulating culture with the growth on the irradiated cellulose has a lag-phase, which duration reduces when the cellulose cleaning by flushing with distillation water. The culture has higher growth and substrate consumption rate when growing by cellulose irradiated in comparison with non-irradiated one. The economical coefficient is the same in using both the irradiated and non-irradiated cellulose. The quantity of forming reducing saccharides, organic acids, methane and carbon dioxide is the same both when cultivating by irradiated cellulose and by non-irradiated. pH of the culture liquid is shifted to the acid nature in the process of growth

  1. Preparation of cellulose II and IIII films by allomorphic conversion of bacterial cellulose I pellicles

    International Nuclear Information System (INIS)

    The structural changes resulting from the conversion of native cellulose I (Cel I) into allomorphs II (Cel II) and IIII (Cel IIII) have usually been studied using powder samples from plant or algal cellulose. In this work, the conversion of Cel I into Cel II and Cel IIII was performed on bacterial cellulose films without any mechanical disruption. The surface texture of the films was observed by atomic force microscopy (AFM) and the morphology of the constituting cellulose ribbons, by transmission electron microscopy (TEM). The structural changes were characterized using solid-state NMR spectroscopy as well as X-ray and electron diffraction. The allomorphic change into Cel II and Cel IIII resulted in films with different crystallinity, roughness and hydrophobic/hydrophilicity surface and the films remained intact during all process of allomorphic conversion. - Highlights: • Description of a method to modify the allomorphic structure of bacterial cellulose films • Preparation of films with specific morphologies and hydrophobic/hydrophilic surface characters • First report on cellulose III films from bacterial cellulose under swelling conditions • Detailed characterization of cellulose II and III films with complementary techniques • Development of films with specific properties as potential support for cells, enzymes, and drugs

  2. Cellulose-clay layered nanocomposite films fabricated from aqueous cellulose/LiOH/urea solution.

    Science.gov (United States)

    Yang, Quanling; Wu, Chun-Nan; Saito, Tsuguyuki; Isogai, Akira

    2014-01-16

    Transparent and flexible cellulose-clay (montmorillonite, MTM) nanocomposite films are prepared from cellulose/LiOH/urea solutions. The results show that the composites possess intercalated nanolayered structures. Almost no Na ions are present in MTM, probably because they are substituted by Li ions. The nanocomposite films possess high mechanical strength and gas barrier properties, and lower coefficients of thermal expansion than those of the original cellulose film. In particular, the composite film of 85% cellulose and 15% MTM has the highest tensile strength and Young's modulus 161 and 180% greater than those of the 100% cellulose film, and coefficient of thermal expansion and oxygen permeability at 50-75% RH decrease to 60 and 42-33%, respectively. Moreover, the initial hydrophilic nature of cellulose film changes to somewhat hydrophobic through incorporation of hydrophilic MTM platelets. This is probably because the orientation of cellulose chains on the film surface changes by the formation of numerous hydrogen bonds between cellulose molecules and MTM platelets. PMID:24188852

  3. Engineering of a novel cellulose-adherent cellulolytic Saccharomyces cerevisiae for cellulosic biofuel production

    Science.gov (United States)

    Liu, Zhuo; Ho, Shih-Hsin; Sasaki, Kengo; den Haan, Riaan; Inokuma, Kentaro; Ogino, Chiaki; van Zyl, Willem H.; Hasunuma, Tomohisa; Kondo, Akihiko

    2016-01-01

    Cellulosic biofuel is the subject of increasing attention. The main obstacle toward its economic feasibility is the recalcitrance of lignocellulose requiring large amount of enzyme to break. Several engineered yeast strains have been developed with cellulolytic activities to reduce the need for enzyme addition, but exhibiting limited effect. Here, we report the successful engineering of a cellulose-adherent Saccharomyces cerevisiae displaying four different synergistic cellulases on the cell surface. The cellulase-displaying yeast strain exhibited clear cell-to-cellulose adhesion and a “tearing” cellulose degradation pattern; the adhesion ability correlated with enhanced surface area and roughness of the target cellulose fibers, resulting in higher hydrolysis efficiency. The engineered yeast directly produced ethanol from rice straw despite a more than 40% decrease in the required enzyme dosage for high-density fermentation. Thus, improved cell-to-cellulose interactions provided a novel strategy for increasing cellulose hydrolysis, suggesting a mechanism for promoting the feasibility of cellulosic biofuel production. PMID:27079382

  4. Evaluation of the cytotoxic effects of ophthalmic solutions containing benzalkonium chloride on corneal epithelium using an organotypic 3-D model

    Directory of Open Access Journals (Sweden)

    Jessen Bart A

    2009-07-01

    Full Text Available Abstract Background Benzalkonium chloride (BAC is a common preservative used in ophthalmic solutions. The aim of this study was to compare the cytotoxic effects of BAC-containing ophthalmic solutions with a BAC-free ophthalmic solution using an organotypic 3-dimensional (3-D corneal epithelial model and to determine the effects of latanoprost ophthalmic solution and its BAC-containing vehicle on corneal thickness in a monkey model. Methods The cytotoxicity of commercially available BAC-containing ophthalmic formulations of latanoprost (0.02% BAC and olopatadine (0.01% BAC was compared to that of BAC-free travoprost and saline in a corneal organotypic 3-D model using incubation times of 10 and 25 minutes. To compare the extent of differentiation of 3-D corneal cultures to monolayer transformed human corneal epithelial (HCE-T cell cultures, expression levels (mRNA and protein of the corneal markers epidermal growth factor receptor, transglutaminase 1 and involucrin were quantified. Finally, latanoprost ophthalmic solution or its vehicle was administered at suprapharmacologic doses (two 30 μL drops twice daily in 1 eye for 1 year in monkey eyes, and corneal pachymetry was performed at baseline and at weeks 4, 13, 26 and 52. Results In the 3-D corneal epithelial culture assays, there were no significant differences in cytotoxicity between the BAC-containing latanoprost and olopatadine ophthalmic solutions and BAC-free travoprost ophthalmic solution at either the 10- or 25-minute time points. The 3-D cultures expressed higher levels of corneal epithelial markers than the HCE-T monolayers, indicating a greater degree of differentiation. There were no significant differences between the corneal thickness of monkey eyes treated with latanoprost ophthalmic solution or its vehicle (both containing 0.02% BAC and untreated eyes. Conclusion The lack of cytotoxicity demonstrated in 3-D corneal cultures and in monkey studies suggests that the levels of BAC

  5. New biphasic monocomponent composite material obtained by the partial oxypropylation of bacterial cellulose; Novo material composito bifasico monocomponente obtido pela oxipropilacao parcial de celulose bacteriana

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    This study aimed to partial oxypropylation of bacterial cellulose (CB), as well as the characterization of pure CB, oxypropylated CB (CBO) and oxypropylated CB after Soxhlet extraction with hexane (CBOE). The oxypropylation reaction was carried out by propylene oxide polymerization, catalyzed by KOH, in the presence of CB The CB samples, before and after modification, were subjected to analysis of scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). It was possible verify that the partial transformation of bacterial cellulose by inserting a layer of thermoplastic polymer on its surface occurred efficiently, obtaining a biphasic monocomponent composite material. (author)

  6. The Effect of Live Classical Piano Music on the Vital Signs of Patients Undergoing Ophthalmic Surgery

    Science.gov (United States)

    Camara, Jorge G.; Ruszkowski, Joseph M.; Worak, Sandra R.

    2008-01-01

    Context Music and surgery. Objective To determine the effect of live classical piano music on vital signs of patients undergoing ophthalmic surgery. Design Retrospective case series. Setting and Patients 203 patients who underwent various ophthalmologic procedures in a period during which a piano was present in the operating room of St. Francis Medical Center. [Note: St. Francis Medical Center has recently been renamed Hawaii Medical Center East.] Intervention Demographic data, surgical procedures, and the vital signs of 203 patients who underwent ophthalmic procedures were obtained from patient records. Blood pressure, heart rate, and respiratory rate measured in the preoperative holding area were compared with the same parameters taken in the operating room, with and without exposure to live piano music. A paired t-test was used for statistical analysis. Main outcome measure Mean arterial pressure, heart rate, and respiratory rate. Results 115 patients who were exposed to live piano music showed a statistically significant decrease in mean arterial blood pressure, heart rate, and respiratory rate in the operating room compared with their vital signs measured in the preoperative holding area (P < .0001). The control group of 88 patients not exposed to live piano music showed a statistically significant increase in mean arterial blood pressure (P < .0002) and heart rate and respiratory rate (P < .0001). Conclusion Live classical piano music lowered the blood pressure, heart rate, and respiratory rate in patients undergoing ophthalmic surgery. PMID:18679538

  7. Ophthalmic Artery Embolization as Pretreatment of Orbital Exenteration for Conjunctival Squamous Cell Carcinoma

    International Nuclear Information System (INIS)

    The aim of this study is to describe the effect of transarterial embolization from the ophthalmic artery as a pretreatment for orbital exenteration. A 75-year-old Chinese man with a 7-year history of gradual increase of the left eye swelling showed a massive conjunctival tumor growing outwardly from the interpalpebral fissure and had no light perception in the left eye. Magnetic resonance imaging showed orbital invasion of the tumor around the left eyeglobe. The initial surgery for the planned orbital exenteration was discontinued after skin incision around the orbital margin due to massive hemorrhage. The patient underwent transarterial embolization with gelatin sponge (Spongel) of the feeding arteries from the left ophthalmic artery and, the next day, had orbital exenteration with well-controllable bleeding and reconstruction with free vascularized anterolateral thigh cutaneous flap transfer. Pathologically, well-differentiated squamous cell carcinoma proliferated in exophytic, papillary, and nested fashions, arising from the bulbar conjunctiva. Tumor cells were also found in the conjunctival stroma around the vessels. The sclera at the equator had a perforated site with tumor cell invasion, but no intraocular invasion was found. Hematoxylin-positive gelatin sponges were found inside the orbital vessels and large choroidal vessels. In conclusion, transarterial embolization of feeding arteries arising from the ophthalmic artery is a useful pretreatment to control bleeding at orbital exenteration for malignancy.

  8. Interferometric And Microscopic Measurements Of Surface Finish Appearance Evaluations Of Ophthalmic Lens Edges

    Science.gov (United States)

    Gamble, M.; Mezghani, S.; El Mansori, M.; Divo, F.

    2011-01-01

    Surface appearance and product material integrity are important features that will affect product functionality, reliability and customer confidence. Yet despite this, and perhaps surprisingly, lens surface inspection is still undertaken visually with undefined criteria, varying levels of quality expertise, and differing moods of inspectors. In this paper, an objective quality inspection method for the polished edge of ophthalmic lenses is developed. Four defect categorizes have been indentified on the machined edge of non-acceptable lenses: chatter marks, linear, creep and cracks. Chatter matters have an irregular surface with waviness. The linear defect has a linear defect along the lens' edge surface. Creep has deformation of the surface due to the material removal process. Cracks have cracks along the surface of the lens. The developed technique was applied to several ophthalmic lens materials (Polycarbonate, CR39, high index materials) that contain defects of diverse shapes and sizes in different locations. Results show the effectiveness of the developed inspection technique for ophthalmic lens quality assurance and defect identification. It was also found that there is a correlation between the scale-sensitive fractal dimension parameter and surface finish appearance.

  9. Clinical utility of 3% diquafosol ophthalmic solution in the treatment of dry eyes

    Directory of Open Access Journals (Sweden)

    Koh S

    2015-05-01

    Full Text Available Shizuka Koh Department of Ophthalmology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan Abstract: Diquafosol is a drug used for dry eye treatment with a novel mechanism of action. It stimulates the secretion of tear fluid and mucin on the ocular surface, thus enabling us to selectively treat the tear film layer, playing an important role in the establishment of the concept of “Tear Film Oriented Therapy (TFOT”, an effective therapeutic approach to dry eye in Japan. The 3% diquafosol ophthalmic solution has been widely used for the treatment of dry eye in clinical practice, and it is currently available in Japan and South Korea. This review provides an overview of the clinical utility of 3% diquafosol ophthalmic solution, focusing on the results of clinical studies on various types of dry eye, including aqueous-deficient dry eye, short tear film breakup time-type dry eye, and post dry eye after laser in situ keratomileusis. It also introduces the additive effect of diquafosol on sodium hyaluronate monotherapy for dry eye, and the effect of 3% diquafosol ophthalmic solution for dry eye-related conditions. Additionally, it summarizes the ocular effects of diquafosol in healthy human eyes. Lastly, the importance of improving tear film stability in dry eye treatment, as well as general advances in dry eye treatments, are described. Keywords: diquafosol, dry eye, mucin secretion, fluid secretion, ocular surface, vision

  10. Color Doppler Imaging of Ophthalmic Arteries : Age Related Changes in the Normal Subjects

    International Nuclear Information System (INIS)

    Color Doppler imaging (CDI) with Doppler spectral analysis was done to evaluate the age related changes of the ophthalmic arteries in 60 normotensive subjects (Age : 19∼64y, mean =38.3y, M : F = 1 : 1). A 7 MHz linear transducer for small parts (Acuson L7384) was used. The ophthalmic artery about 1∼1.5 cm behind the optic nerve head was depicted by the CDI. The maximum peak velocity (S1), the second peak velocity (S2), the maximum peak diastolic velocity (D1) and the end diastolic velocity (D*2) were recorded. Additionally, the piteously index(PI), the resistive index (RI), the ratio of S1 to S2 (S1 / S2) and the ratio of S1 to D1 (S1 / D1) were calculated. Correlation between the age and the above indices (ratio) was estimated. PI, RI, S1 / S2 and S1 / D1 declined progressively as a function of advancing age. The S1 / S2 showed the strongest inverse correlation with age (r = -0.667). The meaning of the S2's in old age is not clear. It could be related to the decreased compliance of the aged ophthalmic arteries

  11. Doppler sonographic evaluation of ophthalmic arterial flow pattern in hypertensive patients

    International Nuclear Information System (INIS)

    To compare the Doppler velocity waveform pattern of ophthalmic artery of hypertensive patients with that of normotensive subjects. Doppler velocity waveform was obtained from ophthalmic artery in 45 hypertensive patients and 60 normotensive subjects. Both hypertensives and normotensive subjects were classified according to age into those younger than and those older than 45 years. Doppler indices(pulsatility index(PI), resistance index(RI), the first systolic peak/the second systolic peak(S1/S2), the first systolic peak/diastolic peak(S1/D)) measured in hypertensive patients were compared with normotensive subjects. Among the various doppler indices, only S1/S2 showed significant difference(P < 0.05) between the hypertensive patients and normotensive subjects younger than 45 years. Doppler velocity waveform of hypertensive patients older than 45 years showed no significant difference from that of normotensive subjects with corresponding age. Doppler velocity waveform of ophthalmic artery in hypertensive patients younger than 45 years shows pattern with S2 higher than that of normotensive subjects. High S2 component(reflective-wave) may represent increased vascular impedance due to vasococonstriction of retinal arterioles in hypertensive patients

  12. Superior ophthalmic vein approach for endovascular treatment of dural cavernous sinus fistulas

    International Nuclear Information System (INIS)

    Objective: To investigate the method for surgical exposure the superior ophthalmic vein with embolization of the cavernous sinus dural arteriovenous fistula and evaluate its efficacy and safety. Methods: Surgical exposure of the superior ophthalmic vein was performed by eyelid incision and followed by catheterization and embolization with micro-coils for 16 patients with cavernous sinus dural arteriovenous fistulas. Results: Clinical cure was achieved in all patients and complete angiographic obliteration of fistula was documented in 15 patients (94%). Residual fistula was left in 1 patients with compact occlusion via pterygoid drainage but disappeared one month later by manual compression of the carotid artery. Headache and vomiting were the most common symptoms after the embolization, other 2 patients had mild diplopia and relieved within two months. No permanent procedure-related morbidity and recurrence occurred during clinical follow up for 5 months to 6 years. Conclusion: Surgical exposure of the superior ophthalmic vein for embolization of cavernous sinus dural arteriovenous fistula is a safe and efficient method. (authors)

  13. Diode-light transillumination for ophthalmic plaque localization around juxtapapillary choroidal melanomas

    International Nuclear Information System (INIS)

    Purpose: An evaluation of plaque-mounted diode-light transillumination (DLT) for localization of episcleral plaques beneath juxtapapillary tumors. Methods and materials: Two patients scheduled for radiotherapy for juxtapapillary melanomas were offered DLT as an additional method of ophthalmic plaque localization. Plaques were constructed by affixing 4 non-heat producing, light-emitting diodes with their apertures flush with the episcleral outer surface of the plaque's rim. Bio-implantable epoxy was used to encapsulate the electronic components. Then the plaques were loaded with 103Pd seeds. After the eye-plaques were sewn to the episclera covering the base of the intraocular tumors, the diode-lights were illuminated, viewed and recorded. Photodocumentation of the relative position of the 4 lights around tumor's base was obtained in both cases. Results: Digital images of plaque-mounted diode retro-transillumination were obtained. No evidence of diode-light toxicity was noted. Both tumors were found to be covered by the ophthalmic plaques. Conclusion: Juxtapapillary tumors are often difficult or impossible to visualize with standard transillumination techniques and have been associated with poor local control rates. We have developed plaque-mounted DLT in an effort to improve ophthalmic plaque localization. Retrobulbar transillumination was viewed by indirect ophthalmoscopy and recorded with video-imaging. This technique provides unique photographic documentation of episcleral plaque localization beneath juxtapapillary tumors

  14. In vitro and in vivo evaluation of ocular inserts of ofloxacin

    Directory of Open Access Journals (Sweden)

    Tanwar Y.S.

    2007-06-01

    Full Text Available Ocular inserts of ofloxacin were prepared with objectives of reducing the frequency of administration, obtaining controlled release and greater therapeutic efficacy in the treatment of eye infections such as conjunctivitis, keratitis, corneal ulcers, etc. Polyvinyl alcohol (PVA ofloxacin films were prepared by mercury substrate method. The ocular inserts were evaluated for drug-excipient interaction, physico-chemical characteristics, microbiological and in vitro and in vivo release studies.  There was no interaction between drug and excipients as revealed by UV absorption and IR spectra of the pure drug, medicated and placebo formulations. The weight and thickness of the inserts were in the range of 57.3-126.0 mg and 55.6-99.3 microns, respectively for different formulations; casting of rate-controlling membrane increased the weight and thickness of the inserts. Tensile strength and percent elongation at break varied with the nature of rate-controlling membrane and film thickness. Moisture vapour transmission through films followed zero-order kinetics and decreased with increase in film thickness. The drug content varied from 99.53-99.86%. The method of exposure to UV radiation was used for sterilization of ocular inserts and no microbial growth was observed in any formulation during sterility testing by direct inoculation method. The influence of rate-controlling membrane of different polymers of ethyl cellulose (EC and polymethacrylates (Eudragit RL100, Eudragit RS100 on release kinetics was studied. The drug release for prepared formulations with rate-controlling membrane of EC, Eudragit RS100 (ERS, Eudragit RL 100 (ERL was found to be 85.80, 93.85 and 98.71%, respectively and followed zero-order kinetics. Ocular insert F3 with rate-controlling membrane of Eudragit RS100, when inserted into the eye of rabbit showed controlled release up to 24 hours. There was a good correlation between in vitro and in vivo release data. The developed

  15. Laser cleaning of particulates from paper: Comparison between sized ground wood cellulose and pure cellulose

    International Nuclear Information System (INIS)

    Visible laser cleaning of charcoal particulates from yellow acid mechanical ground wood cellulose paper was compared with that from bleached sulphite softwood cellulose paper. About one order of magnitude of fluence range is available for a cleaning dynamics between the cleaning threshold and the destruction threshold for two laser pulses. Wood cellulose paper exhibited a higher destruction threshold of the original paper than that of the contaminated specimen because of heat transfer from the hot or evaporating charcoal particulates. In contrast, the contaminated bleached cellulose paper exhibited a higher destruction threshold due to shading by the particulates. The graphite particles are not only detached thermo-mechanically, but also by evaporation or combustion. A cleaning effect was found also outside the illuminated areas due to lateral blasting. Infrared measurements revealed dehydration/dehydrogenation reactions and cross-links by ether bonds together with structural changes of the cellulose chain arrangement and the degree of crystallinity.

  16. Laser cleaning of particulates from paper: Comparison between sized ground wood cellulose and pure cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Arif, S.; Kautek, W., E-mail: wolfgang.kautek@univie.ac.at

    2013-07-01

    Visible laser cleaning of charcoal particulates from yellow acid mechanical ground wood cellulose paper was compared with that from bleached sulphite softwood cellulose paper. About one order of magnitude of fluence range is available for a cleaning dynamics between the cleaning threshold and the destruction threshold for two laser pulses. Wood cellulose paper exhibited a higher destruction threshold of the original paper than that of the contaminated specimen because of heat transfer from the hot or evaporating charcoal particulates. In contrast, the contaminated bleached cellulose paper exhibited a higher destruction threshold due to shading by the particulates. The graphite particles are not only detached thermo-mechanically, but also by evaporation or combustion. A cleaning effect was found also outside the illuminated areas due to lateral blasting. Infrared measurements revealed dehydration/dehydrogenation reactions and cross-links by ether bonds together with structural changes of the cellulose chain arrangement and the degree of crystallinity.

  17. Acid hydrolysis of cellulosic fibres: Comparison of bleached kraft pulp, dissolving pulps and cotton textile cellulose.

    Science.gov (United States)

    Palme, Anna; Theliander, Hans; Brelid, Harald

    2016-01-20

    The behaviour of different cellulosic fibres during acid hydrolysis has been investigated and the levelling-off degree of polymerisation (LODP) has been determined. The study included a bleached kraft pulp (both never-dried and once-dried) and two dissolving pulps (once-dried). Additionally, cotton cellulose from new cotton sheets and sheets discarded after long-time use was studied. Experimental results from the investigation, together with results found in literature, imply that ultrastructural differences between different fibres affect their susceptibility towards acid hydrolysis. Drying of a bleached kraft pulp was found to enhance the rate of acid hydrolysis and also result in a decrease in LODP. This implies that the susceptibility of cellulosic fibres towards acid hydrolysis is affected by drying-induced stresses in the cellulose chains. In cotton cellulose, it was found that use and laundering gave a substantial loss in the degree of polymerisation (DP), but that the LODP was only marginally affected. PMID:26572472

  18. Surface modification of cellulose by PCL grafts

    Energy Technology Data Exchange (ETDEWEB)

    Paquet, Olivier; Krouit, Mohammed; Bras, Julien [Laboratoire de Genie des Procedes Papetiers (UMR 5518 CNRS-CTP-INPG), Grenoble INP-Pagora, 461 Rue de la papeterie, F-38402 St Martin d' Heres (France); Thielemans, Wim [Driving Innovation in Chemistry and Chemical Engineering (DICE), School of Chemistry and Process and Environmental Research Division - Faculty of Engineering, University of Nottingham, University Park, Nottingham, NG7 2RD (United Kingdom); Belgacem, Mohamed Naceur, E-mail: Naceur.Belgacem@efpg.inpg.fr [Laboratoire de Genie des Procedes Papetiers (UMR 5518 CNRS-CTP-INPG), Grenoble INP-Pagora, 461 Rue de la papeterie, F-38402 St Martin d' Heres (France)

    2010-02-15

    Two cellulosic substrates (microcrystalline cellulose, MCC, and bleached kraft softwood pulps, BSK) were grafted by polycaprolactone (PCL) chains with different molecular weights, following a three-step procedure using non-swelling conditions in order to limit the reaction to their surface. First, one of the two OH PCL ends was blocked by phenyl isocyanate and the reaction product (adduct 1) was subsequently reacted with 2,4-toluene diisocyanate (adduct 2) to provide it with an NCO function, capable of reacting with cellulose. The ensuing PCL-grafted cellulosic materials were characterized by weight gain, elemental analysis, contact angle measurements, attenuated total reflexion-Fourier transform infrared (ATR-FTIR), X-ray photoelectron spectroscopy (XPS) and biodegradation tests. The modification was proven to occur by the presence of nitrogen atoms in the elemental analysis tests and XPS spectra of modified and soxhlet-extracted cellulose. The contact angle measurements have also shown that the surface became as hydrophobic as PCL itself. The polar component of the surface energy of cellulosic substrates before treatment was found to be about 32 and 10 mJ m{sup -2}, for MCC and BSK, respectively. This value vanished to practically zero after grafting with different PCLs. The strategy proposed in the present work is original since, to the best of our knowledge, this paper reports for the first time the chemical 'grafting onto' of the cellulose surface by PCL macromolecular structures, with the aim of obtaining fibre-matrix co-continuous fully sustainable and biodegradable composite materials.

  19. Effect of ionizing radiation on starch and cellulose

    International Nuclear Information System (INIS)

    The investigation is reported of the effects of ionizing radiation both on macromolecular systems generally and on polysaccharides, starch and cellulose. Attention is focused on changes in the physical and physico-chemical properties of starch and cellulose, such as starch swelling, gelation, viscosity, solubility, reaction with iodine, UV, IR and ESR spectra, chemical changes resulting from radiolysis and from the effect of amylases on irradiated starch, changes in cellulose fibre strength, water absorption, stain affinity, and also the degradation of cellulose by radiation and the effect of cellulases on irradiated cellulose. Practical applications of the findings concerning cellulose degradation are discussed. (author)

  20. AC loss performance of CS insert coil

    International Nuclear Information System (INIS)

    The ITER Central Solenoid (CS) model coil and the CS insert coil were fabricated, and the test was carried out. The AC loss measurement of the coil is one of the most important tests to determine coil performance. The AC loss of a short sample conductor for the CS insert coil was measured by using the calorimetric method, and the coupling time constants of the conductor were estimated to be 30 ms and 20 ms for pulse and discharge tests, respectively. The AC loss of the CS insert coil was measured by using the calorimetric method for pulse and discharge tests. The coupling time constant estimated from the result of the pulse tests was 34 ms and almost equal to that of the short sample. The coupling time constant for the discharge test was estimated to be 140 ms and about 4 times that of the pulse test. (author)