21 CFR 886.1420 - Ophthalmic lens gauge.

Science.gov (United States)

2010-04-01

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

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 surgical...

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 a...

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 increasing...

21 CFR 886.4750 - Ophthalmic eye shield.

Science.gov (United States)

2010-04-01

...) 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 to... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic eye shield. 886.4750 Section 886.4750...

Ophthalmic Disorders in Adults with Down Syndrome

Directory of Open Access Journals (Sweden)

Sharon J. Krinsky-McHale

2012-01-01

Full Text Available A myriad of ophthalmic disorders is associated with the phenotype of Down syndrome including strabismus, cataracts, and refractive errors potentially resulting in significant visual impairment. Ophthalmic sequelae have been extensively studied in children and adolescents with Down syndrome but less often in older adults. In-depth review of medical records of older adults with Down syndrome indicated that ophthalmic disorders were common. Cataracts were the most frequent ophthalmic disorder reported, followed by refractive errors, strabismus, and presbyopia. Severity of intellectual disability was unrelated to the presence of ophthalmic disorders. Also, ophthalmic disorders were associated with lower vision-dependent functional and cognitive abilities, although not to the extent that was expected. The high prevalence of ophthalmic disorders highlights the need for periodic evaluations and individualized treatment plans for adults with Down syndrome, in general, but especially when concerns are identified.

Metallization of bacterial cellulose for electrical and electronic device manufacture

Science.gov (United States)

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.

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

OpenAIRE

Gaynes, Bruce I; Onyekwuluje, Anne

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...

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, or...

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 powers...

21 CFR 886.3100 - Ophthalmic tantalum clip.

Science.gov (United States)

2010-04-01

... blood vessels in the eye. (b) Classification. Class II (special controls). The device is exempt from the...) 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 permanently...

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 is...

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 5...

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 aqueous...

Communication: an ophthalmic practice issue.

Science.gov (United States)

Whitton, S J

1995-12-01

In the 1990's communication becomes an ophthalmic practice issue. The present ophthalmic climate of cost containment, downsizing, budget cuts, and lack of appreciation of contributions, results in a low staff morale. Recognition of the effects of job satisfaction and productivity led one group to seek solutions. A communication task force was formed to identify problems and the appropriate interventions.

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...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1415 Ophthalmic trial lens frame. (a) Identification. An opthalmic trial lens frame is a mechanical device intended to hold trial lenses for vision...

Sildenafil dilates ophthalmic artery in type 2 diabetic patients

Directory of Open Access Journals (Sweden)

Akeel AMH Zwain

2013-08-01

Full Text Available 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 enrolled in this study, 18 with type 2 diabetes mellitus matched with 17 normal individuals. Ophthalmic artery was insonated through a transorbital window using colored Doppler equipment with transcranial Doppler facility. Ophthalmic artery reactivity was assessed using breath holding/hyperventilation test, before and after giving 50 mg oral sildenafil. Results: It was found that in both normal subjects and diabetic patients, sildenafil increased baseline control of mean flow velocity of ophthalmic artery significantly (p 0.05 after sildenafil, in normal and diabetic groups. There was a significant increase of resistive index of ophthalmic artery flow in diabetic patients compared with that of normal subject (p < 0.05. Sildenafil decreased resistive index of ophthalmic artery flow significantly only in diabetic patients (p < 0.05. Conclusion: Sildenafil increased MFVopa, but had no significant effect on vasoreactivity of ophthalmic artery; sildenafil decreased resistive index only in type 2 diabetic patients.

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

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

Science.gov (United States)

Marlowe, Zora T; Davio, Stephen R

2014-01-01

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. 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. 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 below the declared concentration for drops expressed at the beginning of the 2-week dosing regimen and significantly above the declared concentration for drops expressed near the end of the dosing

21 CFR 524.1200b - Kanamycin ophthalmic aqueous solution.

Science.gov (United States)

2010-04-01

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

Alternative methods of ophthalmic treatment in Russia.

Science.gov (United States)

Vader, L

1994-04-01

Russian ophthalmic nurses and physicians are using alternative methods of treatment to supplement traditional eye care. As acupuncture and iridology become more popular in the United States, ophthalmic nurses need to be more knowledgeable about these treatments and the implications for patients.

Cellulose Degradation by Cellulose-Clearing and Non-Cellulose-Clearing Brown-Rot Fungi

OpenAIRE

Highley, Terry L.

1980-01-01

Cellulose degradation by four cellulose-clearing brown-rot fungi in the Coniophoraceae—Coniophora prasinoides, C. puteana, Leucogyrophana arizonica, and L. olivascens—is compared with that of a non-cellulose-clearing brown-rot fungus, Poria placenta. The cellulose- and the non-cellulose-clearing brown-rot fungi apparently employ similar mechanisms to depolymerize cellulose; most likely a nonenzymatic mechanism is involved.

Functional analysis of the cellulose synthase-like genes CSLD1, CSLD2 and CSLD4 in tip-growing arabidopsis cells

DEFF Research Database (Denmark)

Bernal Giraldo, Adriana Jimena; Yoo, Cheol-Min; Mutwil, Marek

2008-01-01

A reverse genetic approach was used to investigate the functions of three members of the cellulose synthase superfamily in Arabidopsis (Arabidopsis thaliana), CELLULOSE SYNTHASE-LIKE D1 (CSLD1), CSLD2, and CSLD4. CSLD2 is required for normal root hair growth but has a different role from that pre......A reverse genetic approach was used to investigate the functions of three members of the cellulose synthase superfamily in Arabidopsis (Arabidopsis thaliana), CELLULOSE SYNTHASE-LIKE D1 (CSLD1), CSLD2, and CSLD4. CSLD2 is required for normal root hair growth but has a different role from...... for insertions in these genes were partially rescued by reduced temperature growth. However, this was not the case for a double mutant homozygous for insertions in both CSLD2 and CSLD3, suggesting that there may be partial redundancy in the functions of these genes. Mutants in CSLD1 and CSLD4 had a defect...

Sustained ophthalmic delivery of highly soluble drug using pH-triggered inner layer-embedded contact lens.

Science.gov (United States)

Zhu, Qiang; Cheng, Hongbo; Huo, Yingnan; Mao, Shirui

2018-06-10

In the present work the feasibility of using inner layer-embedded contact lenses (CLs) to achieve sustained release of highly water soluble drug, betaxolol hydrochloride (BH) on the ocular surface was investigated. Blend film of cellulose acetate and Eudragit S100 was selected as the inner layer, while silicone hydrogel was used as outer layer to construct inner layer-embedded contact lenses. Influence of polymer ratio in the blend film on in vitro drug release behavior in phosphate buffered solution or simulated tear fluid was studied and drug-polymer interaction, erosion and swelling of the blend film were characterized to better understand drug-release mechanism. Storage stability of the inner layer-embedded contact lenses in phosphate buffer solution was also conducted, with ignorable drug loss and negligible change in drug release pattern within 30 days. In vivo pharmacokinetic study in rabbits showed sustained drug release for over 240 h in tear fluid, indicating prolonged drug precorneal residence time. In conclusion, cellulose acetate/Eudragit S100 inner layer-embedded contact lenses are quite promising as controlled-release carrier of highly water soluble drug for ophthalmic delivery. Copyright © 2018 Elsevier B.V. All rights reserved.

A new kind of monitor for ophthalmic operation

International Nuclear Information System (INIS)

Li, G; Wang, L L; Wang, Y; Lin, L; Jiang, W; Lu, Stephen C-Y; Besio, Walter G

2005-01-01

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

A new kind of monitor for ophthalmic operation

Energy Technology Data Exchange (ETDEWEB)

Li, G [College of Precision Instrument and Opto-Electronics Engineering, Tianjin University, Tianjin, 300072 (China); Wang, L L [College of Precision Instrument and Opto-Electronics Engineering, Tianjin University, Tianjin, 300072 (China); Wang, Y [College of Precision Instrument and Opto-Electronics Engineering, Tianjin University, Tianjin, 300072 (China); Lin, L [College of Precision Instrument and Opto-Electronics Engineering, Tianjin University, Tianjin, 300072 (China); Jiang, W [College of Precision Instrument and Opto-Electronics Engineering, Tianjin University, Tianjin, 300072 (China); Lu, Stephen C-Y [College of Precision Instrument and Opto-Electronics Engineering, Tianjin University, Tianjin, 300072 (China); Besio, Walter G [Biomedical Engineering Program, and Center for Biomedical Engineering and Rehabilitation Science Louisiana Tech. University, LA (United States)

2005-01-01

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.

determinants of general anaesthesia for ophthalmic surgery

African Journals Online (AJOL)

DR. CHARLES IMARENGIAYE

1999-08-01

Objectives: To study the pattern of anaesthesia for ophthalmic procedures in order to improve the scheduling of cases in the ophthalmic operating room. Methods: The surgical register of the operating room from. August 01, 1999 to July 31, 2004 was examined, to document the types of procedure, timing of surgery (elective ...

Ophthalmic gels: Past, present and future.

Science.gov (United States)

Al-Kinani, Ali A; Zidan, Ghada; Elsaid, Naba; Seyfoddin, Ali; Alani, Adam W G; Alany, Raid G

2018-02-15

Aqueous gels formulated using hydrophilic polymers (hydrogels) along with those based on stimuli responsive polymers (in situ gelling or gel forming systems) continue to attract increasing interest for various eye health-related applications. They allow the incorporation of a variety of ophthalmic pharmaceuticals to achieve therapeutic levels of drugs and bioactives at target ocular sites. The integration of sophisticated drug delivery technologies such as nanotechnology-based ones with intelligent and environment responsive systems can extend current treatment duration to provide more clinically relevant time courses (weeks and months instead of hours and days) which will inevitably reduce dose frequency, increase patient compliance and improve clinical outcomes. Novel applications and design of contact lenses and intracanalicular delivery devices along with the move towards integrating gels into various drug delivery devices like intraocular pumps, injections and implants has the potential to reduce comorbidities caused by glaucoma, corneal keratopathy, cataract, diabetic retinopathies and age-related macular degeneration. This review describes ophthalmic gelling systems with emphasis on mechanism of gel formation and application in ophthalmology. It provides a critical appraisal of the techniques and methods used in the characterization of ophthalmic preformed gels and in situ gelling systems along with a thorough insight into the safety and biocompatibility of these systems. Newly developed ophthalmic gels, hydrogels, preformed gels and in situ gelling systems including the latest in the area of stimuli responsive gels, molecularly imprinted gels, nanogels, 3D printed hydrogels; 3D printed devices comprising ophthalmic gels are covered. Finally, new applications of gels in the production of artificial corneas, corneal wound healing and hydrogel contact lenses are described. Copyright © 2017 Elsevier B.V. All rights reserved.

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.

21 CFR 886.4350 - Manual ophthalmic surgical instrument.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Manual ophthalmic surgical instrument. 886.4350 Section 886.4350 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... suturing needle, lachrymal probe, trabeculotomy probe, cornea-sclera punch, ophthalmic retractor...

Formulation and development of ophthalmic in situ gel for the treatment ocular inflammation and infection using application of quality by design concept.

Science.gov (United States)

Patel, Nirav; Thakkar, Vaishali; Metalia, Viral; Baldaniya, Lalji; Gandhi, Tejal; Gohel, Mukesh

2016-09-01

The conventional liquid ophthalmic delivery systems exhibit short pre-corneal residence time and the relative impermeability to the cornea which leads to poor ocular bioavailability. The aim of this study was to apply quality by design (QbD) for development of dexamethasone sodium phosphate (DSP) and tobramycin sulfate (TS)-loaded thermoresponsive ophthalmic in situ gel containing Poloxamer 407 and hydroxyl propyl methyl cellulose (HPMC) K4M for prolonging the pre-corneal residence time, ocular bioavability and decreases the frequency of administration of dosage form. The material attributes and the critical quality attributes (CQA) of the in situ gel were identified. Central composite design (CCD) was adopted to optimize the formulation. The ophthalmic in situ forming gels were prepared by cold method. Materials attributes were the amount of Poloxamer 407 and HPMC and CQA identified were Gel strength, mucoadhesive index, gelation temperature and % of drug release of both drug. Optimized batch (F*) containing 16.75% poloxamer 407 and 0.54% HPMC K4M were exhibited all results in acceptable limits. Compared with the marketed formulation, optimized in situ gel showed delayed Tmax, improved Cmax and AUC in rabbit aqueous humor, suggesting the sustained drug release and better corneal penetration and absorption. According to the study, it could be concluded that DSP and TS would be successfully formulated as in situ gelling mucoadhesive system for the treatment of steroid responsive eye infections with the properties of sustained drug release, prolonged ocular retention and improved corneal penetration.

Treatment of neuro-ophthalmic sarcoidosis.

Science.gov (United States)

Frohman, Larry P

2015-03-01

Because of the rarity of neuro-ophthalmic sarcoidosis, there are no therapeutic guidelines based on evidence-based medicine for this disorder. Review of literature combined with personal experience. Corticosteroids are the preferred initial therapy for neuro-ophthalmic sarcoidosis. If patients cannot tolerate the requisite dose of corticosteroid needed to control their disease, or if corticosteroids fail to adequately control the disease process, the choices of a second agent are based on the consideration of rapidity of clinical response and the safety profile. Although methotrexate and mycophenolate mofetil are the medications that are often selected after corticosteroid failure, more rapidly acting agents that have been used are infliximab and intravenous cyclophosphamide.

Audit of Referrals to an Ophthalmic Outpatient Clinic of a Tertiary ...

African Journals Online (AJOL)

Objectives: To determine the referral pattern and assess the quality and accuracy of referral letters to the ophthalmic outpatient clinic of University of Nigeria Teaching Hospital, Enugu. Methods: This study is a prospective cross-sectional survey of all new ophthalmic referrals to the ophthalmic outpatient clinic at University of ...

Degree and duration of corneal anesthesia after topical application of 0.4% oxybuprocaine hydrochloride ophthalmic solution in ophthalmically normal dogs.

Science.gov (United States)

Douet, Jean-Yves; Michel, Julien; Regnier, Alain

2013-10-01

To assess the anesthetic efficacy and local tolerance of topically applied 0.4% oxybuprocaine ophthalmic solution to in dogs and compare its effects with those of 1% tetracaine solution. 34 ophthalmically normal Beagles. Dogs were assigned to 2 groups, and baseline corneal touch threshold (CTT) was measured bilaterally with a Cochet-Bonnet aesthesiometer. Dogs of group 1 (n = 22) received a single drop of 0.4% oxybuprocaine ophthalmic solution in one eye and saline (0.9% NaCl) solution (control treatment) in the contralateral eye. Dogs of group 2 (n = 12) received a single drop of 0.4% oxybuprocaine ophthalmic solution in one eye and 1% tetracaine ophthalmic solution in the contralateral eye. The CTT of each eye was measured 1 and 5 minutes after topical application and then at 5-minute intervals until 75 minutes after topical application. CTT changes over time differed significantly between oxybuprocaine-treated and control eyes. After instillation of oxybuprocaine, maximal corneal anesthesia (CTT = 0) was achieved within 1 minute, and CTT was significantly decreased from 1 to 45 minutes, compared with the baseline value. No significant difference in onset, depth, and duration of corneal anesthesia was found between oxybuprocaine-treated and tetracaine-treated eyes. Conjunctival hyperemia and chemosis were detected more frequently in tetracaine-treated eyes than in oxybuprocaine-treated eyes. Topical application of oxybuprocaine and tetracaine similarly reduced corneal sensitivity in dogs, but oxybuprocaine was less irritating to the conjunctiva than was tetracaine.

Diquafosol ophthalmic solution 3 %: a review of its use in dry eye.

Science.gov (United States)

Keating, Gillian M

2015-05-01

Diquafosol ophthalmic solution 3 % (Diquas(®)) is a P2Y2 receptor agonist that promotes tear fluid and mucin secretion and is currently approved in Japan and South Korea for the treatment of dry eye. In randomized, double-blind, multicentre trials in patients with dry eye, significantly greater improvements in fluorescein and rose bengal staining scores were seen with diquafosol ophthalmic solution 3 % than with placebo, and diquafosol ophthalmic solution 3 % was noninferior to sodium hyaluronate ophthalmic solution 0.1 % in terms of the improvement in the fluorescein staining score and more effective than sodium hyaluronate ophthalmic solution 0.1 % in terms of the improvement in the rose bengal staining score. The efficacy of diquafosol ophthalmic solution 3 % in the treatment of dry eye was maintained in the longer term, with improvements also seen in subjective dry eye symptoms, and was also shown in a real-world setting. Diquafosol ophthalmic solution 3 % also demonstrated efficacy in various specific dry eye disorders, including aqueous-deficient dry eye, short tear film break-up time dry eye, obstructive meibomian gland dysfunction, dry eye following laser in situ keratomileusis surgery and dry eye following cataract surgery, as well as in contact lens wearers and visual display terminal users. Diquafosol ophthalmic solution 3 % was generally well tolerated in patients with dry eye, with eye irritation the most commonly reported adverse event. In conclusion, diquafosol ophthalmic solution 3 % is a useful option for the treatment of dry eye.

Rate of bacterial eradication by ophthalmic solutions of fourth-generation fluoroquinolones.

Science.gov (United States)

Callegan, Michelle C; Novosad, Billy D; Ramadan, Raniyah T; Wiskur, Brandt; Moyer, Andrea L

2009-04-01

Antibacterial activity of ophthalmic fourth-generation fluoroquinolones has traditionally been evaluated by comparing only their active ingredients, gatifloxacin and moxifloxacin. However, ophthalmic formulations of fourth-generation fluoroquinolones differ in terms of the inclusion of preservatives. While gatifloxacin ophthalmic solution 0.3% (Zymar; Allergan, Inc., Irvine, CA, USA) contains 0.005% benzalkonium chloride (BAK), moxifloxacin ophthalmic solution 0.5% (Vigamox; Alcon Laboratories, Inc., Fort Worth, TX, USA) is preservative-free. Recent studies have demonstrated that the presence of BAK dramatically affects the antibacterial activity of the ophthalmic formulation of gatifloxacin. This study was designed to compare the kill rates of ophthalmic solutions of fourth-generation fluoroquinolones against isolates of common ocular bacterial pathogens. Approximately 5.6 log(10) colony-forming units (CFU)/mL of Haemophilus influenzae (n=1), Streptococcus pneumoniae (n=1), Staphylococcus aureus (n=2), methicillin-resistant Staphylococcus aureus (MRSA) (n=4), methicillinresistant Staphylococcus epidermidis (MRSE) (n=4), and fluoroquinolone-resistant S. epidermidis (n=1) were incubated with ophthalmic solutions of either gatifloxacin or moxifloxacin. Viable bacteria were quantified at specific time points up to 60 minutes. Gatifloxacin 0.3% completely eradicated H. influenzae and Strep. pneumoniae in 5 minutes, one of two S. aureus isolates in 15 minutes, and the other S. aureus isolate in 60 minutes. Gatifloxacin 0.3% completely killed all MRSA, MRSE, and fluoroquinolone-resistant S. epidermidis isolates in 15 minutes. Moxifloxacin 0.5% completely eradicated Strep. pneumoniae and one of four MRSA isolates in 60 minutes. All other isolates incubated with moxifloxacin 0.5% retained viable bacteria ranging from 1.8 to 4.4 log(10) CFU/mL. The ophthalmic solution of gatifloxacin 0.3% eradicated bacteria that frequently cause postoperative ocular infections

76 FR 30176 - Dermatologic and Ophthalmic Drugs Advisory Committee; Notice of Meeting

Science.gov (United States)

2011-05-24

... committee will discuss biologics license application (BLA) 125387, aflibercept ophthalmic solution, proposed...] Dermatologic and Ophthalmic Drugs Advisory Committee; Notice of Meeting AGENCY: Food and Drug Administration...: Dermatologic and Ophthalmic Drugs Advisory Committee. General Function of the Committee: To provide advice and...

Ocular lens availability of glutathione from collagen inserts for protection of eye from radiation

International Nuclear Information System (INIS)

Omer, S.A.

2003-01-01

Full text: Ocular inserts of glutathione ( G ) were prepared using 1 % collagen solution containing free G ,liposomal G and liposomal G with Concanavalin A ,a specific targeting agent of G to ocular lens. These inserts have to be sterilized for in-vivo ophthalmic application by exposure to U V radiation for 2 hr. using dry ice and acetone for protection of G from thermal degradation. In vitro release characteristics of G (17.0 μ mole) from the prepared inserts were investigated at 37deg C in phosphate buffer pH 7.4 . The results of release data showed that the release of G from inserts were arranged in the following order, free G, liposomal G with or without Concanavalin A. The extent of uptake of G from the collagen inserts by rabbit cornea was also tested. The results of ocular lens availability of G from collagen inserts revealed that a highly significant increase in the uptake of G by ocular lenses,where the percentages drug uptake from the applied doses at T max were 1.12% (p(0.05), 2.12% (p(0.01) and 3.4% (p(0.001) in case of using collagen inserts containing free G, liposomal G and liposomal G with Concanavalin A respectively. That is to say,lipid nature of liposomes together with Concanavlin A improved the penetration of the entrapped hydrophilic G through corneal barrier to the ocular lenses

Development and Effects of FTY720 Ophthalmic Solution on Corneal Allograft Survival.

Science.gov (United States)

Liu, Zhaochuan; Lin, Haotian; Huang, Chulong; Chen, Wan; Xiang, Wu; Geng, Yu; Chen, Weirong

2015-11-12

Fingolimod (FTY720), a novel class of sphingosine 1-phosphate receptor modulators, has received special interest among ophthalmologists, particularly given that oral administration of FTY720 has proven to effectively treat corneal graft rejection in animal models. However, no studies have examined the performance of FTY720 as an ophthalmic solution in reducing corneal rejection in high-risk corneal rejection models, and the stability and ocular irritation profile of FTY720 ophthalmic solution are also unknown. Thus, we developed 0.1%, 0.2% and 0.5% FTY720 ophthalmic solutions and evaluated their chemical stabilities under various storage conditions with high- performance liquid chromatography. To investigate the ocular irritancy of the FTY720 ophthalmic solution, New Zealand albino rabbits were subjected to the Draize test. Furthermore, classic, well-established rat allogenic penetrating keratoplasty models were used to investigate the anti-rejection efficacy of the tested FTY720 ophthalmic solutions. We found that the non-irritating 0.5% FTY720 ophthalmic solution could prolong corneal allograft survival in rats with significant efficacy for about one month. Furthermore, no significant concentration changes occurred in any of the types of FTY720 ophthalmic solutions within three months. These results revealed crucial profiles of FTY720 ophthalmic solutions and warrant further investigation and optimization of FTY720 in the anti-rejection therapy after keratoplasty.

Lifitegrast Ophthalmic Solution 5%: A Review in Dry Eye Disease.

Science.gov (United States)

Keating, Gillian M

2017-02-01

Lifitegrast is a novel small molecule integrin antagonist that blocks the binding of intercellular adhesion molecule 1 (ICAM-1) to lymphocyte function-associated antigen 1 (LFA-1). Lifitegrast ophthalmic solution 5% (Xiidra™) was recently approved in the USA for the treatment of dry eye disease. The efficacy of lifitegrast ophthalmic solution 5% was compared with vehicle in a 12-week phase 2 study and three 12-week phase 3 studies (OPUS-1, OPUS-2 and OPUS-3) in patients with dry eye disease. Taken as a whole, results of these trials support the treatment effect of lifitegrast ophthalmic solution 5% in improving a symptom of dry eye disease (i.e. the change from baseline to day 84 in the eye dryness visual analogue scale score) and a sign of dry eye disease (i.e. the change from baseline to day 84 in the inferior corneal fluorescein staining score). Lifitegrast ophthalmic solution 5% was generally well tolerated. In conclusion, lifitegrast ophthalmic solution 5% provides a new option for the treatment of dry eye disease.

Allergic Contact Dermatitis to Ophthalmic Medications: Relevant Allergens and Alternative Testing Methods.

Science.gov (United States)

Grey, Katherine R; Warshaw, Erin M

Allergic contact dermatitis is an important cause of periorbital dermatitis. Topical ophthalmic agents are relevant sensitizers. Contact dermatitis to ophthalmic medications can be challenging to diagnose and manage given the numerous possible offending agents, including both active and inactive ingredients. Furthermore, a substantial body of literature reports false-negative patch test results to ophthalmic agents. Subsequently, numerous alternative testing methods have been described. This review outlines the periorbital manifestations, causative agents, and alternative testing methods of allergic contact dermatitis to ophthalmic medications.

Readability assessment of online ophthalmic patient information.

Science.gov (United States)

Edmunds, Matthew R; Barry, Robert J; Denniston, Alastair K

2013-12-01

Patients increasingly use the Internet to access information related to their disease, but poor health literacy is known to impact negatively on medical outcomes. Multiple agencies have recommended that patient-oriented literature be written at a fourth- to sixth-grade (9-12 years of age) reading level to assist understanding. The readability of online patient-oriented materials related to ophthalmic diagnoses is not yet known. To assess the readability of online literature specifically for a range of ophthalmic conditions. Body text of the top 10 patient-oriented websites for 16 different ophthalmic diagnoses, covering the full range of ophthalmic subspecialties, was analyzed for readability, source (United Kingdom vs non-United Kingdom, not for profit vs commercial), and appropriateness for sight-impaired readers. Four validated readability formulas were used: Flesch Reading Ease Score (FRES), Flesch-Kincaid Grade Level (FKGL), Simple Measure of Gobbledygook (SMOG), and Gunning Fog Index (GFOG). Data were compared with the Mann-Whitney test (for 2 groups) and Kruskal-Wallis test (for more than 2 groups) and correlation was assessed by the Spearman r. None of the 160 webpages had readability scores within published guidelines, with 83% assessed as being of "difficult" readability. Not-for-profit webpages were of significantly greater length than commercial webpages (P = .02) and UK-based webpages had slightly superior readability scores compared with those of non-UK webpages (P = .004 to P readability formula used). Of all webpages evaluated, only 34% included facility to adjust text size to assist visually impaired readers. To our knowledge, this is the first study to assess readability of patient-focused webpages specifically for a range of ophthalmic diagnoses. In keeping with previous studies in other medical conditions, we determined that readability scores were inferior to those recommended, irrespective of the measure used. Although readability is only one

Bilateral IgG4-related ophthalmic disease: a strong indication for systemic imaging.

Science.gov (United States)

Wu, Albert; Andrew, Nicholas H; McNab, Alan A; Selva, Dinesh

2016-10-01

To investigate whether bilateral or unilateral IgG4-related ophthalmic disease (IgG4-ROD) is associated with extra-ophthalmic IgG4-related disease (IgG4-RD). Twin-centre retrospective observational case series of biopsy-confirmed IgG4-ROD. Clinical and radiology data were reviewed for laterality of IgG4-ROD and presence of extra-ophthalmic disease. The literature was reviewed for case series of IgG4-ROD. 40 IgG4-ROD cases were identified, with median follow-up of 36 months. At diagnosis of IgG4-ROD, all cases were screened for extra-ophthalmic disease with physical examination and blood testing. Systemic imaging was performed in 20 (50%) cases due to clinical suspicion of extra-ophthalmic disease. Of the 21 unilateral IgG4-ROD cases, 3 (14%) had extra-ophthalmic involvement. Of the 19 bilateral cases, 15 (79%) had extra-ophthalmic involvement. Extra-ophthalmic involvement was strongly associated with bilateral IgG4-ROD (pIgG4-ROD is strongly associated with extra-ophthalmic IgG4-RD. We recommend that imaging of the neck, chest, abdomen and pelvis be performed for all bilateral cases. Systemic imaging should also be considered in unilateral cases as a significant proportion of these patients will also have extra-ophthalmic disease. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Diquafosol ophthalmic solution for dry eye treatment.

Science.gov (United States)

Nakamura, Masatsugu; Imanaka, Takahiro; Sakamoto, Asuka

2012-07-01

There has been rapid progress in our understanding of dry eye pathogenesis, as well as the development of improved diagnostic clinical tests. Various types of dry eye treatment drugs have been developed. This review summarizes the basic and clinical research carried out in the development of diquafosol for ophthalmic use. Diquafosol is a dinucleotide, purinoreceptor P2Y(2) receptor agonist. Basic pharmacological studies have shown that it acts on P2Y(2) receptors at the ocular surface, to promote tear and mucin secretion via elevated intracellular Ca(2+) concentrations. Diquafosol also improves tear and mucin secretion in experimental dry eye models. Based on the results of laboratory experiments, the authors conducted a series of clinical studies in patients with dry eye disease. Diquafosol was effective in the treatment of dry eye disease at an optimal dose of 3% six times a day. In comparison to commercially available 0.1% sodium hyaluronate ophthalmic solution, 3% diquafosol ophthalmic solution showed non-inferiority in improving corneal fluorescein staining scores and superiority in improving keratoconjunctival Rose Bengal staining scores. Diquafosol ophthalmic solution has a novel mechanism of action that is characterized by its stimulatory effects on tear and mucin secretion. This drug has the potential to be effective in patients with tear film instability and short break-up time type of dry eye, which are essential factors in dry eye pathogenesis.

Comparison of corneal safety and intraocular pressure-lowering effect of tafluprost ophthalmic solution with other prostaglandin ophthalmic solutions.

Science.gov (United States)

Kumagami, Takeshi; Wakiyama, Harumi; Kusano, Mao; Kajiyama, Ayano; Miura, Yoko; Uematsu, Masafumi; Yoneda, Ai; Kurihara, Junko; Suzuma, Kiyoshi; Kitaoka, Takashi

2014-05-01

The benzalkonium chloride (BAK) content of tafluprost ophthalmic solution (Tapros(®): tafluprost) has been reduced to balance corneal safety and preservative effectiveness (old formulation: 0.01%; new formulation: 0.001%). However, no reports have been published on its clinical effect. Therefore, we conducted a clinical research study to compare the safety of BAK-reduced tafluprost on the ocular surface with other prostaglandin ophthalmic solutions. This clinical study included 28 glaucoma patients (28 eyes) with a treatment history of latanoprost ophthalmic solution (Xalatan(®)) or travoprost ophthalmic solution (Travatan Z(®)), who presented with corneal epithelial disorders. The subjects were switched to BAK-reduced tafluprost, and its effect on the ocular surface was examined after 1 and 2 months of treatment [using fluorescein staining score, hyperemia, tear film breakup time, and intraocular pressure (IOP) lowering]. In all analyzed subjects (N=27), the fluorescein staining score was significantly improved after switching to BAK-reduced tafluprost (P<0.0001). Conversely, the IOP-lowering effect was not notably changed. The subjects switched from latanoprost (n=10) showed significant improvement in fluorescein staining score (P<0.05) as well as in IOP lowering (P<0.01). The subjects switched from travoprost (n=17) also showed significant improvement in fluorescein staining score (P<0.001), but without a significant change in IOP lowering. Tafluprost with reduced BAK has potential as a superior antiglaucoma drug, not only for its IOP-lowering effect, but also for its good corneal safety profile.

Comparison of systemic absorption between ofloxacin ophthalmic in situ gels and ofloxacin conventional ophthalmic solutions administration to rabbit eyes by HPLC-MS/MS.

Science.gov (United States)

Li, Jiawei; Zhao, Hainan; Okeke, Chukwunweike Ikechukwu; Li, Lin; Liu, Zhidong; Yin, Zhongpeng; Zhuang, Pengwei; Sun, Jingtong; Wu, Tao; Wang, Meng; Li, Nan; Pi, Jiaxin; Zhang, Qian; Zhang, Rui; Ma, Li; Pang, Xiaochen; Liu, Zhanbiao; Zhang, Li; Fan, Lili

2013-06-25

In recent years, many pharmaceutical scientists have focused on developing the in situ gel-forming systems to overcome the poor bioavailability and therapeutic response exhibited by conventional ophthalmic solutions due to rapid pre-corneal elimination of the drug. The present work was to compare the systemic absorptions of ophthalmic ofloxacin in situ gel with the conventional ofloxacin eye drop after topical instillation to rabbit eyes by HPLC-MS/MS method and also determine the relative contribution of the nasal and the conjunctival mucosae to systemic ofloxacin absorption following topical instillation. The systemic AUC, Cmax, Tmax and Ke for ophthalmic in situ gel and ophthalmic solution after ocular instillation were 202.63±118.85 and 202.25±57.74 ng mL(-1) h, 54.22±28.31 and 48.4±25.97 ng mL(-1), 1.08±0.20 and 1.25±0.88 h, 0.0576±0.0207 and 0.0388±0.0248, respectively. And the values for the ratios of the AUC of anterior chamber of rabbit eye to blood plasma, AUCac/AUCpl, for ofloxacin conventional eye drop and in situ gel were 0.25 and 0.52, respectively. Statistic results showed that there was no significant difference in systemic absorption between the test groups and the reference groups (P>0.05) as both formulations have an AUCsa/AUCpl of 0.35. Therefore, the ophthalmic in situ gel may not decrease the drugs systemic absorption when administered in an equivalent dose as ophthalmic solutions into the rabbit eyes. Copyright © 2013 Elsevier B.V. All rights reserved.

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

International Nuclear Information System (INIS)

Bobleter, O.; Niesner, R.; Roehr, M.

1976-01-01

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 14 C-labeled straw were treated at temperatures of between 200 and 275 0 C. 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

Medical physics aspects of ophthalmic brachytherapy

International Nuclear Information System (INIS)

Sharma, S.D.; Shanta, A.; Palani Selvam, T.; Tripathi, U.B.; Bhatt, B.C.

2004-11-01

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 90 Sr/ 90 Y 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 125 I seed sources by the Radiopharmaceuticals Division, BARC. This report presents a brief description on the clinical, dosimetry and radiation safety aspects of 90 Sr/ 90 Y and 106 Ru/ 106 Rh beta ray and 125 I 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 90 Sr/ 90 Y and 106 Ru/ 106 Rh beta and 125 I gamma ophthalmic plaques are given in Section II and Section III, respectively. Section IV contains the single seed dosimetry data of BARC OcuProsta 125 I seed as well as dosimetry data of typical eye plaques loaded with BARC OcuProsta 125 I 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)

New biphasic monocomponent composite material obtained by the partial oxypropylation of bacterial cellulose

International Nuclear Information System (INIS)

Rosa, Joyce Rover; Silva, Ingrid S.V. da; Pasquini, Daniel; Santos, Daniele B. dos; Barud, Hernane S.; Ribeiro, Sidney J.L.

2011-01-01

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)

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

Science.gov (United States)

Kim, Yong-Kyu; Jung, Cheolkyu; Woo, Se Joon; Park, Kyu Hyung

2015-12-01

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.

ANAESTHESIA FOR OPHTHALMIC SURGICAL PROCEDURES

African Journals Online (AJOL)

Objective: To review factors influencing the choice of anaesthesia for ophthalmic surgical procedures. ... as risk associated with general anaesthesia (8) they are more .... Wilson ME, Pandey SK, Thakur J. Paediatric cataract blindness in the ...

Cellulose synthase complex organization and cellulose microfibril structure.

Science.gov (United States)

Turner, Simon; Kumar, Manoj

2018-02-13

Cellulose consists of linear chains of β-1,4-linked glucose units, which are synthesized by the cellulose synthase complex (CSC). In plants, these chains associate in an ordered manner to form the cellulose microfibrils. Both the CSC and the local environment in which the individual chains coalesce to form the cellulose microfibril determine the structure and the unique physical properties of the microfibril. There are several recent reviews that cover many aspects of cellulose biosynthesis, which include trafficking of the complex to the plasma membrane and the relationship between the movement of the CSC and the underlying cortical microtubules (Bringmann et al. 2012 Trends Plant Sci. 17 , 666-674 (doi:10.1016/j.tplants.2012.06.003); Kumar & Turner 2015 Phytochemistry 112 , 91-99 (doi:10.1016/j.phytochem.2014.07.009); Schneider et al. 2016 Curr. Opin. Plant Biol. 34 , 9-16 (doi:10.1016/j.pbi.2016.07.007)). In this review, we will focus on recent advances in cellulose biosynthesis in plants, with an emphasis on our current understanding of the structure of individual catalytic subunits together with the local membrane environment where cellulose synthesis occurs. We will attempt to relate this information to our current knowledge of the structure of the cellulose microfibril and propose a model in which variations in the structure of the CSC have important implications for the structure of the cellulose microfibril produced.This article is part of a discussion meeting issue 'New horizons for cellulose nanotechnology'. © 2017 The Author(s).

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

International Nuclear Information System (INIS)

Ayaz, Tunahan; Akansel, Gur.; Hayirlioglu, Alper; Arslan, Arzu; Suer, Necdet; Kuru, Ihsan

2003-01-01

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

Polymyxin B and Trimethoprim Ophthalmic

Science.gov (United States)

Polymyxin B and trimethoprim ophthalmic combination is used to treat bacterial infections of the eye including conjunctivitis (pinkeye; infection ... inside and outer parts of the eyelid). Polymyxin B and trimethoprim are in a class of medications ...

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

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. (a...

Neuro-ophthalmic and clinical characteristics of brain tumours in a ...

African Journals Online (AJOL)

Background: Anecdotally, increasing number of patients are seen at Korle Bu Teaching Hospital (KBTH) with brain tumour. Neuro-ophthalmic symptoms and signs may help in timely diagnosis and intervention. Objective: To evaluate the neuro-ophthalmic and clinical characteristics of brain tumour in patients presenting at a ...

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.

Cellulose is not just cellulose

DEFF Research Database (Denmark)

Hidayat, Budi Juliman; Felby, Claus; Johansen, Katja Salomon

2012-01-01

are 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...... or enzymatic hydrolysis of plant cell walls is carried out simultaneously with the application of shear stress, plant cells such as fibers or tracheids break at their dislocations. At present it is not known whether specific carbohydrate binding modules (CBMs) and/or cellulases preferentially access cellulose...

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.

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.

Challenges Encountered Using Ophthalmic Anesthetics in Space Medicine

Science.gov (United States)

Bayuse, T.; Law, J.; Alexander, D.; Moynihan, S.; LeBlanc, C.; Langford, K.; Magalhaes, L.

2015-01-01

On orbit, ophthalmic anesthetics are used for tonometry and off-nominal corneal examinations. Proparacaine has been flown traditionally. However, the manufacturers recently changed its storage requirements from room temperature storage to refrigerated storage to preserve stability and prolong the shelf-life. Since refrigeration on orbit is not readily available and there were stability concerns about flying proparacaine unrefrigerated, tetracaine was selected as an alternative ophthalmic anesthetic in 2013. We will discuss the challenges encountered flying and using these anesthetics on the International Space Station.

The international council of ophthalmology: vision for ophthalmic education in an interdependent world.

Science.gov (United States)

Lee, Andrew G; Golnik, Karl C; Tso, Mark O M; Spivey, Bruce; Miller, Kathleen; Gauthier, Tina-Marie

2012-10-01

To describe the emerging strategic global perspective of the International Council of Ophthalmology (ICO) efforts in ophthalmic education. A global perspective describing how the development of sophisticated educational tools in tandem with information technology can revolutionize ophthalmic education worldwide. Review of ICO educational tools, resources, and programs that are available to ophthalmic educators across the globe. With the explosive growth of the Internet, the ability to access medical information in the most isolated of locations is now possible. Through specific ICO initiatives, including the ICO curricula, the "Teaching the Teachers" program, and the launching of the new ICO Center for Ophthalmic Educators, the ICO is providing ophthalmic educators across the globe with access to standardized but customizable educational programs and tools to better train ophthalmologists and allied eye care professionals throughout the world. Access to educational tools and strengthening of global learning will help providers meet the goals of VISION 2020 and beyond in eliminating avoidable blindness. It is the intent of the ICO that its programs for ophthalmic educators, including conferences, courses, curricula, and online resources, result in better-trained ophthalmologists and eye care professionals worldwide. Copyright © 2012 Elsevier Inc. All rights reserved.

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

OpenAIRE

Kim, Yong-Kyu; Jung, Cheolkyu; Woo, Se Joon; Park, Kyu Hyung

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...

Properties of cellulose derivatives produced from radiation-Modified cellulose pulps

International Nuclear Information System (INIS)

Iller, Edward; Stupinska, Halina; Starostka, Pawel

2007-01-01

The aim of project was elaboration of radiation methods for properties modification of cellulose pulps using for derivatives production. The selected cellulose pulps were exposed to an electron beam with energy 10 MeV in a linear accelerator. After irradiation pulps underwent the structural and physico-chemical investigations. The laboratory test for manufacturing carboxymethylocellulose (CMC), cellulose carbamate (CC) and cellulose acetate (CA) with cellulose pulps irradiated dose 10 and 15 kGy have been performed. Irradiation of the pulp influenced its depolimerisation degree and resulted in the drop of viscosity of CMC. However, the expected level of cellulose activation expressed as a rise of the substitution degree or increase of the active substance content in the CMC sodium salt was not observed. In the case of cellulose esters (CC, CA) formation, the action of ionising radiation on cellulose pulps with the dose 10 and 15 kGy enables obtaiment of the average values of polimerisation degree as required for CC soluble in aqueous sodium hydroxide solution. The properties of derivatives prepared by means of radiation and classic methods were compared

Synthesis and characterization of cellulose derivatives obtained from bacterial cellulose

International Nuclear Information System (INIS)

Oliveira, Rafael L. de; Barud, Hernane; Ribeiro, Sidney J.L.; Messaddeq, Younes

2011-01-01

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 13 C. 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)

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...

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. ...

International Council of Ophthalmology: Refocusing Ophthalmic Education in the Asia-Pacific Region and Beyond.

Science.gov (United States)

Golnik, Karl; Mayorga, Eduardo; Spivey, Bruce; Ritch, Robert; Gauthier, Tina-Marie

2012-01-01

The International Council of Ophthalmology (ICO) is a global organization with a regional focus. Working in partnership with supranational and ICO member societies, the ICO is building a "World Alliance for Sight" to improve access to the highest-quality eye care worldwide. Designed to preserve and restore vision on an international scale, the ICO initiative, "Refocusing Ophthalmic Education," enhances ophthalmic education of residents, subspecialists, medical students, and allied eye care personnel by redefining the most effective ways to teach and in creating beneficial educational opportunities. The "Teaching the Teachers" program helps ophthalmic educators incorporate more effective methods of training and continuing professional development to meet societal needs, achieved in part through regional courses for residency program directors; symposia, and keynote talks presented by ICO's World Ophthalmology Educational Colloquium, Conferences for Ophthalmic Educators, and ophthalmic surgical competency rubrics. Recognizing that standardized curricula are essential for consistent ophthalmic education, the ICO has developed a curricular framework whereby goals, expectations, knowledge base, competencies, and technical training are delineated. The ICO is defining worldwide models of team training and compiling best practice, which will include training-program accreditation to ensure improvement in the education of ophthalmologists. International Council of Ophthalmology Web-based teaching courses, a Webinar Network, and a technology blog further support information and communication technologies for teaching and learning. At the ICO's Center for Ophthalmic Educators (educators.icoph.org), trainers will find valuable teaching resources in multiple languages as well as ways to share ideas and collaborate with peers and other ophthalmic educators.

INFLUENCE OF CELLULOSE POLYMERIZATION DEGREE AND CRYSTALLINITY ON KINETICS OF CELLULOSE DEGRADATION

OpenAIRE

Edita Jasiukaitytė-Grojzdek,; Matjaž Kunaver,; Ida Poljanšek

2012-01-01

Cellulose was treated in ethylene glycol with p-toluene sulfonic acid monohydrate as a catalyst at different temperatures. At the highest treatment temperature (150 °C) liquefaction of wood pulp cellulose was achieved and was dependant on cellulose polymerization degree (DP). Furthermore, the rate of amorphous cellulose weight loss was found to increase with cellulose degree of polymerization, while the rate of crystalline cellulose weight loss was reciprocal to the size of the crystallites. ...

Determination of permeability coefficients of ophthalmic drugs through different layers of porcine, rabbit and bovine eyes

OpenAIRE

Nagel, Stefan; Guthoff, Rudolf F.; Weitschies, Werner; Seidlitz, Anne; Kristl, Albin; Žakelj, Simon; Loch, Christian

2015-01-01

To treat ophthalmic diseases like glaucoma or inflammatory disorders topically applied ophthalmic formulations such as eye drops are usually used. In addition, novel ophthalmic implants releasing drug substances locally into different parts of the eye are available today. In the work presented here, the permeability coefficients of selected drugs (ciprofloxacin hydrochloride, lidocaine hydrochloride, timolol maleate) for ophthalmic tissues were determined using side-by-side diffusion chambers...

Comparison of Drug Concentrations in Human Aqueous Humor after the Administration of 0.3% Gatifloxacin Ophthalmic Gel, 0.3% Gatifloxacin and 0.5% Levofloxacin Ophthalmic Solutions.

Science.gov (United States)

Ding, Wenting; Ni, Weiling; Chen, Huilian; Yuan, Jingqun; Huang, Xiaodan; Zhang, Zheng; Wang, Yao; Yu, Yibo; Yao, Ke

2015-01-01

To investigate the penetration of 0.3% gatifloxacin ophthalmic gel, 0.3% gatifloxacin ophthalmic solution and 0.5% levofloxacin ophthalmic solution into aqueous humor after topical application. Age-related cataract patients (150 eyes in 150 cases) receiving phacoemulsification were randomly divided into three groups: a 0.3% gatifloxacin gel group (n=50), a 0.3% gatifloxacin solution group (n=50), and a 0.5% levofloxacin solution group (n=50). Each group was administered one drop of gel or solution every 15 minutes for four doses. Aqueous samples were collected at different time points after the last drop. High pressure liquid chromatography (HPLC) was applied to determine the concentrations. The one-way ANOVA analysis was performed. Our data indicated that the concentration of the gatifloxacin gel group was higher than that of the gatifloxacin solution group at all time points (P solution group at 120.0 min and 180.0 min (Psolutions reached their peak values at 60.0 min. 0.3% gatifloxacin ophthalmic gel application produced highest aqueous humor drug concentration, maintained the longest time, had the best penetration and bioavailability.

Cellulose-Hemicellulose Interactions at Elevated Temperatures Increase Cellulose Recalcitrance to Biological Conversion

Energy Technology Data Exchange (ETDEWEB)

Mittal, Ashutosh [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Himmel, Michael E [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Kumar, Rajeev [University of California, Riverside; Oak Ridge National Laboratory; ; Smith, Micholas Dean [Oak Ridge National Laboratory; University of Tennessee; Petridis, Loukas [Oak Ridge National Laboratory; University of Tennessee; Ong, Rebecca G. [Michigan Technological University; Cai, Charles M. [University of California, Riverside; Oak Ridge National Laboratory; Balan, Venkatesh [University of Houston; Dale, Bruce E. [Michigan State University; Ragauskas, Arthur J. [Oak Ridge National Laboratory; University of Tennessee; Smith, Jeremy C. [Oak Ridge National Laboratory; University of Tennessee; Wyman, Charles E. [University of California, Riverside; Oak Ridge National Laboratory

2018-01-23

It has been previously shown that cellulose-lignin droplets' strong interactions, resulting from lignin coalescence and redisposition on cellulose surface during thermochemical pretreatments, increase cellulose recalcitrance to biological conversion, especially at commercially viable low enzyme loadings. However, information on the impact of cellulose-hemicellulose interactions on cellulose recalcitrance following relevant pretreatment conditions are scarce. Here, to investigate the effects of plausible hemicellulose precipitation and re-association with cellulose on cellulose conversion, different pretreatments were applied to pure Avicel(R) PH101 cellulose alone and Avicel mixed with model hemicellulose compounds followed by enzymatic hydrolysis of resulting solids at both low and high enzyme loadings. Solids produced by pretreatment of Avicel mixed with hemicelluloses (AMH) were found to contain about 2 to 14.6% of exogenous, precipitated hemicelluloses and showed a remarkably much lower digestibility (up to 60%) than their respective controls. However, the exogenous hemicellulosic residues that associated with Avicel following high temperature pretreatments resulted in greater losses in cellulose conversion than those formed at low temperatures, suggesting that temperature plays a strong role in the strength of cellulose-hemicellulose association. Molecular dynamics simulations of hemicellulosic xylan and cellulose were found to further support this temperature effect as the xylan-cellulose interactions were found to substantially increase at elevated temperatures. Furthermore, exogenous, precipitated hemicelluloses in pretreated AMH solids resulted in a larger drop in cellulose conversion than the delignified lignocellulosic biomass containing comparably much higher natural hemicellulose amounts. Increased cellulase loadings or supplementation of cellulase with xylanases enhanced cellulose conversion for most pretreated AMH solids; however, this approach

78 FR 27971 - Determination That REV-EYES (Dapiprazole Hydrochloride Ophthalmic Solution), 0.5%, Was Not...

Science.gov (United States)

2013-05-13

...] Determination That REV-EYES (Dapiprazole Hydrochloride Ophthalmic Solution), 0.5%, Was Not Withdrawn From Sale... ophthalmic solution), 0.5%, was not withdrawn from sale for reasons of safety or effectiveness. This... ophthalmic solution, 0.5%, if all other legal and regulatory requirements are met. FOR FURTHER INFORMATION...

Synthesis and characterization of amorphous cellulose from triacetate of cellulose

International Nuclear Information System (INIS)

Vega-Baudrit, Jose; Sibaja, Maria; Nikolaeva, Svetlana; Rivera A, Andrea

2014-01-01

It was carried-out a study for the synthesis and characterization of amorphous cellulose starting from cellulose triacetate. X-rays diffraction was used in order to obtain the cellulose crystallinity degree, also infrared spectroscopy FTIR was used. (author)

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.

Approaching zero cellulose loss in cellulose nanocrystal (CNC) production: recovery and characterization of cellulosic solid residues (CSR) and CNC

Science.gov (United States)

Q.Q. Wang; J.Y. Zhu; R.S. Reiner; S.P. Verrill; U. Baxa; S.E. McNeil

2012-01-01

This study demonstrated the potential of simultaneously recovering cellulosic solid residues (CSR) and producing cellulose nanocrystals (CNCs) by strong sulfuric acid hydrolysis to minimize cellulose loss to near zero. A set of slightly milder acid hydrolysis conditions than that considered as “optimal” were used to significantly minimize the degradation of cellulose...

Comparison of the effectiveness of contemporary ophthalmic lenses against β radiation

International Nuclear Information System (INIS)

Dunlap, J.H.; Harvey, P.W.; Schwing, R.L.

1977-01-01

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.)

Radiation modification of cellulose pulps. Preparation of cellulose derivatives

International Nuclear Information System (INIS)

Iller, E.; Zimek, Z.; Stupinska, H.; Mikolajczyk, W; Starostka, P.

2005-01-01

One of the most common methods of cellulose pulp modification (activation) applied in the production process of cellulose derivatives is the treatment of the pulp with NaOH solutions leading to the formation of alkalicellulose. The product then undergoes a prolonged process of maturation by its storage under specific conditions. The goal of the process is lowering of the molecular weight of cellulose down to the level resulting from various technological requirements. The process is time-consuming and costly; besides, it requires usage of large-capacity technological vessels and produces considerable amounts of liquid waste. Therefore, many attempts have been made to limit or altogether eliminate the highly disadvantageous stage of cellulose treatment with lye. One of the alternatives proposed so far is the radiation treatment of the cellulose pulp. In the pulp exposed to an electron beam, the bonds between molecules of D-antihydroglucopiranoses loosen and the local crystalline lattice becomes destroyed. This facilitates the access of chemical reagents to the inner structure of the cellulose and, in consequence, eliminates the need for the prolonged maturation of alkalicellulose, thus reducing the consumption of chemicals by the whole process. Research aimed at the application of radiation treatment of cellulose pulp for the production of cellulose derivatives has been conducted by a number of scientific institutions including the Institute of Nuclear Chemistry and Technology, Institute of Biopolymers and Chemical Fibres, and Pulp and Paper Research Institute. For the investigations and assessment of the molecular, hypermolecular, morphologic properties and the chemical reactivity, cellulose pulps used for chemical processing, namely Alicell, Borregaard and Ketchikan, as well as paper pulps made from pine and birch wood were selected. The selected cellulose pulps were exposed to an electron beam with an energy of 10 MeV generated in a linear electron accelerator

76 FR 71044 - Determination That TRAVATAN (Travoprost Ophthalmic Solution), 0.004%, Was Not Withdrawn From Sale...

Science.gov (United States)

2011-11-16

...] Determination That TRAVATAN (Travoprost Ophthalmic Solution), 0.004%, Was Not Withdrawn From Sale for Reasons of... Drug Administration (FDA) has determined that TRAVATAN (travoprost ophthalmic solution), 0.004%, was... approve abbreviated new drug applications (ANDAs) for travoprost ophthalmic solution, 0.004%, if all other...

Development and Evaluation of Diclofenac Sodium Loaded-N-Trimethyl Chitosan Nanoparticles for Ophthalmic Use.

Science.gov (United States)

Asasutjarit, Rathapon; Theerachayanan, Thitaree; Kewsuwan, Prartana; Veeranodha, Sukitaya; Fuongfuchat, Asira; Ritthidej, Garnpimol C

2015-10-01

The ophthalmic preparation of diclofenac sodium (DC) for relieving ocular inflammation is presently available in the market only as an eye drop solution. Due to its low occular bioavailability, it requires frequent application leading to low patients' compliance and quality of life. This study was conducted to develop formulations of DC loaded-N-trimethyl chitosan nanoparticles (DC-TMCNs) for ophthalmic use to improve ocular biavailabiltiy of DC. DC-TMCNs varied in formulation compositions were prepared using ionic gelation technique and evaluated for their physicochemical properties, drug release, eye irritation potential, and ophthalmic absorption of diclofenac sodium. N-Trimethyl chitosan (TMC) with a 49.8% degree of quaternization was synthesized and used for DC-TMCNs production. The obtained DC-TMCNs had particle size in a range of 130-190 nm with zeta potential values of +4 to +9 mV and drug entrapment efficiencies of more than 70% depending on the content of TMC and sodium tripolyphosphate (TPP). The optimized DC-TMCNs formulation contained TMC, DC, and TPP at a weight ratio of TMC/DC/TPP = 3:1:1. Their lyophilized product reconstituted with phosphate buffer solution pH 5.5 possessed a drug release pattern that fitted within the zero-order model. The eye irritation tests showed that DC-TMCNs were safe for ophthalmic use. The in vivo ophthalmic drug absorption study performed on rabbits indicated that DC-TMCNs could improve ophthalmic bioavailability of DC. Results of this study suggested that DC-TMCNs had potential for use as an alternative to conventional DC eye drops for ophthalmic inflammation treatment.

A Profile of Neuro-Ophthalmic Practice Around the World.

Science.gov (United States)

Frohman, Larry P

2018-03-01

To compare contrast neuro-ophthalmic practice in various countries, an 18-question survey was sent to the international North American Neuro-Ophthalmology Society (NANOS) members in the spring of 2016. At least 1 NANOS member was contacted for each non-US nation in the NANOS membership roster. If there were multiple NANOS members from 1 country, multiple were contacted. If responses were received from more than 1 person from a single country, the first response received was used as the source data. The survey (in English) was emailed to 47 NANOS members from 31 countries. Twenty responses were received representing members from 15 nations. In all 15 nations, at least half of the neuro-ophthalmologists were trained as ophthalmologists. In 60% of nations, at least half of the neuro-ophthalmologists were trained internally, whereas in 33% of countries, at least half were trained in the United States. The number of physicians who practiced a significant amount of neuro-ophthalmology ranged from low (0.08/million, India) to high (3.10/million, Israel). Countries having the highest percentage of neuro-ophthalmologists exclusively practicing neuro-ophthalmology also were those with better patient access to neuro-ophthalmic care. Requirement of approval to see a neuro-ophthalmologist or for imaging studies requested by neuro-ophthalmologists was not typical. In most nations, academic neuro-ophthalmologists were paid a straight salary. In no nation were neuro-ophthalmologists paid more than another ophthalmic subspecialty. Individual national health care system designs and compensation models have had a profound influence on the rewards and challenges that face neuro-ophthalmologists. There seems to have been a connection between recognition of the discipline, financial rewards of neuro-ophthalmic practice, conditions that permit full-time neuro-ophthalmic practice, and patient access to care. A higher percentage of gross national product for health care did not seem to

Engineering Aspergillus oryzae A-4 through the chromosomal insertion of foreign cellulase expression cassette to improve conversion of cellulosic biomass into lipids.

Science.gov (United States)

Lin, Hui; Wang, Qun; Shen, Qi; Ma, Junwei; Fu, Jianrong; Zhao, Yuhua

2014-01-01

A genetic modification scheme was designed for Aspergillus oryzae A-4, a natural cellulosic lipids producer, to enhance its lipid production from biomass by putting the spotlight on improving cellulase secretion. Four cellulase genes were separately expressed in A-4 under the control of hlyA promoter, with the help of the successful development of a chromosomal genetic manipulation system. Comparison of cellulase activities of PCR-positive transformants showed that these transformants integrated with celA gene and with celC gene had significantly (pcellulase gene in A2-2 and D1-B1 was subsequently investigated. It was noted that cellulase expression repressed biomass formation but enhanced lipid accumulation; whereas the inhibitory effect on cell growth would be shielded during cellulosic lipids production owing to the essential role of cellulase in substrate utilization. Different metabolic profiles also existed between A2-2 and D1-B1, which could be attributed to not only different transgene but also biological impacts of different integration. Overall, both simultaneous saccharification and lipid accumulation were enhanced in A2-2 and D1-B1, resulting in efficient conversion of cellulose into lipids. A regulation of cellulase secretion in natural cellulosic lipids producers could be a possible strategy to enhance its lipid production from lignocellulosic biomass.

Chick chorioallantoic membrane model for in ovo evaluation of timolol maleate-brimonidine tartrate ocular inserts.

Science.gov (United States)

Ravindran, Vinod Kombath; Repala, Swathi; Subadhra, Sandhya; Appapurapu, Ashok Kumar

2014-06-01

The main aspire of this study was to develop ocular drug delivery system for dual drug glaucoma therapy by timolol maleate-brimonidine tartrate and endeavor the possibility of biocompatibility studies by in ova studies. Matrix type, both hydrophilic and lipophilic polymers, and reservoir-type ocular inserts of timolol maleate were prepared using hydrophilic polymers like polyvinyl alcohol, hydroxyl propyl methyl cellulose K4M and lipophilic polymers like ethylcellulose and eudragit S100 and were optimized. Based on the optimized formulation, triple-layered ocular inserts (reservoir type) of dual drug were prepared by solvent casting technique with an objective of reducing the frequency of administration, obtaining controlled release and greater therapeutic efficacy, preservative free dosage form for the treatment of glaucoma. FTIR spectral studies revealed no pharmaceutical incompatibility and no drug polymer interactions. Maximum drug release (99.18 ± 1.7) was achieved when PVP and HPMC K4M in 1:1 ratio with PEG 400 (0.3 ml) drug reservoir layer was sandwiched between ethyl cellulose as rate control membrane up to 32 h in a controlled fashion. Drug release was by non-Fickian diffusion mechanism for single drug formulation. But in dual drug insert, timolol maleate best fit into zero order and for brimonidine tartrate to Higuchi model and diffusion of drugs from this by non-Fickian diffusion mechanism. In ovo studies suggested that the optimized formulation was found to be sterile, biocompatible and physicochemically stable and support us to claim that the developed formulation was biocompatible.

IN-SITU OPHTHALMIC GELS FOR THE TREATMENT OF EYE DISEASES

OpenAIRE

M. Jothi, S.L. Harikumar* and Geeta Aggarwal

2012-01-01

Topical administration of a drug in the conjunctival cul-de-sac is the treatment of choice for diseases of the anterior segment of eye. Development of ophthalmic drug delivery systems has always been challenging because of the drawbacks with this route, like non-productive absorption, drainage, induced lacrimation, tear turn over, impermeability of drugs to cornea. New approaches have been investigated for delivery of drugs to the eye by means of polymeric delivery of ophthalmic drugs to the ...

Physicotechnical, spectroscopic and thermogravimetric properties of powdered cellulose and microcrystalline cellulose derived from groundnut shells

Directory of Open Access Journals (Sweden)

Chukwuemeka P. Azubuike

2012-09-01

Full Text Available α-Cellulose and microcrystalline cellulose powders, derived from agricultural waste products, that have for the pharmaceutical industry, desirable physical (flow properties were investigated. α–Cellulose (GCN was extracted from groundnut shell (an agricultural waste product using a non-dissolving method based on inorganic reagents. Modification of this α -cellulose was carried out by partially hydrolysing it with 2N hydrochloric acid under reflux to obtain microcrystalline cellulose (MCGN. The physical, spectroscopic and thermal properties of the derived α-cellulose and microcrystalline cellulose powders were compared with Avicel® PH 101, a commercial brand of microcrystalline cellulose (MCCA, using standard methods. X-ray diffraction and infrared spectroscopy analysis showed that the α-cellulose had lower crystallinity. This suggested that treatment with 2N hydrochloric acid led to an increase in the crystallinity index. Thermogravimetric analysis showed quite similar thermal behavior for all cellulose samples, although the α-cellulose had a somewhat lower stability. A comparison of the physical properties between the microcrystalline celluloses and the α-cellulose suggests that microcrystalline cellulose (MCGN and MCCA might have better flow properties. In almost all cases, MCGN and MCCA had similar characteristics. Since groundnut shells are agricultural waste products, its utilization as a source of microcrystalline cellulose might be a good low-cost alternative to the more expensive commercial brand.

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

OpenAIRE

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

2016-01-01

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 with the ...

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

Science.gov (United States)

Isik, Mehmet; Sardon, Haritz; Mecerreyes, David

2014-01-01

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. PMID:25000264

Efficacy of bromfenac sodium ophthalmic solution for treatment of dry eye disease.

Science.gov (United States)

Fujishima, Hiroshi; Fuseya, Miki; Ogata, Masarou; Murat, Dogru

2015-01-01

To evaluate the efficacy of bromfenac sodium ophthalmic solution (BF) in patients with dry eye disease (DED) inadequately controlled by monotherapy with artificial tears (ATs). An investigator-oriented trial with a single-arm, nonrandomized, open-label design. Twenty-six patients, who showed no symptomatic improvement of DED after 1 month of AT treatment, were enrolled. Bromfenac sodium ophthalmic solution was administered adjunctively with AT for 1 month. The BF treatment was then discontinued, and AT treatment alone was continued for 3 months. The signs and symptoms were evaluated at the beginning of BF treatment (Pre), at the end of the combined BF and AT treatment (BF1M), and at 1 and 3 months after discontinuation of BF treatment (Po1M and Po3M, respectively). The dryness scores at BF1M were significantly improved compared with Pre (P ophthalmic solution has improved the dryness of the eye and signs of DED through its anti-inflammatory effects. Nonsteroidal anti-inflammatory drugs were suitable as anti-inflammatory ophthalmic solutions for patients with DED.

Engineering Aspergillus oryzae A-4 through the chromosomal insertion of foreign cellulase expression cassette to improve conversion of cellulosic biomass into lipids.

Directory of Open Access Journals (Sweden)

Hui Lin

Full Text Available A genetic modification scheme was designed for Aspergillus oryzae A-4, a natural cellulosic lipids producer, to enhance its lipid production from biomass by putting the spotlight on improving cellulase secretion. Four cellulase genes were separately expressed in A-4 under the control of hlyA promoter, with the help of the successful development of a chromosomal genetic manipulation system. Comparison of cellulase activities of PCR-positive transformants showed that these transformants integrated with celA gene and with celC gene had significantly (p<0.05 higher average FPAase activities than those strains integrated with celB gene and with celD gene. Through the assessment of cellulosic lipids accumulating abilities, celA transformant A2-2 and celC transformant D1-B1 were isolated as promising candidates, which could yield 101%-133% and 35.22%-59.57% higher amount of lipids than the reference strain A-4 (WT under submerged (SmF conditions and solid-state (SSF conditions, respectively. Variability in metabolism associated to the introduction of cellulase gene in A2-2 and D1-B1 was subsequently investigated. It was noted that cellulase expression repressed biomass formation but enhanced lipid accumulation; whereas the inhibitory effect on cell growth would be shielded during cellulosic lipids production owing to the essential role of cellulase in substrate utilization. Different metabolic profiles also existed between A2-2 and D1-B1, which could be attributed to not only different transgene but also biological impacts of different integration. Overall, both simultaneous saccharification and lipid accumulation were enhanced in A2-2 and D1-B1, resulting in efficient conversion of cellulose into lipids. A regulation of cellulase secretion in natural cellulosic lipids producers could be a possible strategy to enhance its lipid production from lignocellulosic biomass.

Ophthalmic Drug Delivery Systems for Antibiotherapy—A Review

Science.gov (United States)

Dubald, Marion; Bourgeois, Sandrine; Andrieu, Véronique; Fessi, Hatem

2018-01-01

The last fifty years, ophthalmic drug delivery research has made much progress, challenging scientists about the advantages and limitations of this drug delivery approach. Topical eye drops are the most commonly used formulation in ocular drug delivery. Despite the good tolerance for patients, this topical administration is only focus on the anterior ocular diseases and had a high precorneal loss of drugs due to the tears production and ocular barriers. Antibiotics are popularly used in solution or in ointment for the ophthalmic route. However, their local bioavailability needs to be improved in order to decrease the frequency of administrations and the side effects and to increase their therapeutic efficiency. For this purpose, sustained release forms for ophthalmic delivery of antibiotics were developed. This review briefly describes the ocular administration with the ocular barriers and the currently topical forms. It focuses on experimental results to bypass the limitations of ocular antibiotic delivery with new ocular technology as colloidal and in situ gelling systems or with the improvement of existing forms as implants and contact lenses. Nanotechnology is presently a promising drug delivery way to provide protection of antibiotics and improve pathway through ocular barriers and deliver drugs to specific target sites. PMID:29342879

Ophthalmic Drug Delivery Systems for Antibiotherapy—A Review

Directory of Open Access Journals (Sweden)

Marion Dubald

2018-01-01

Full Text Available The last fifty years, ophthalmic drug delivery research has made much progress, challenging scientists about the advantages and limitations of this drug delivery approach. Topical eye drops are the most commonly used formulation in ocular drug delivery. Despite the good tolerance for patients, this topical administration is only focus on the anterior ocular diseases and had a high precorneal loss of drugs due to the tears production and ocular barriers. Antibiotics are popularly used in solution or in ointment for the ophthalmic route. However, their local bioavailability needs to be improved in order to decrease the frequency of administrations and the side effects and to increase their therapeutic efficiency. For this purpose, sustained release forms for ophthalmic delivery of antibiotics were developed. This review briefly describes the ocular administration with the ocular barriers and the currently topical forms. It focuses on experimental results to bypass the limitations of ocular antibiotic delivery with new ocular technology as colloidal and in situ gelling systems or with the improvement of existing forms as implants and contact lenses. Nanotechnology is presently a promising drug delivery way to provide protection of antibiotics and improve pathway through ocular barriers and deliver drugs to specific target sites.

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.

Subspecialization of the ophthalmic literature: a review of the publishing trends of the top general, clinical ophthalmic journals.

Science.gov (United States)

Kumar, Anupma; Cheeseman, Robert; Durnian, Jonathan M

2011-06-01

To investigate the publishing trends of the top general clinical ophthalmic journals and to report: (1) the proportions of articles published in terms of ophthalmic subspecialty, (2) the study design used, (3) any changes in publishing trends, and (4) any differences in the quality of study design between the subspecialties. Retrospective, database review. All original articles published in the top general, clinical ophthalmology journals from 2005 through 2009. All general, clinical ophthalmic journals were selected from the top 20 journals based on 2008 impact factor. All abstracts from original articles were reviewed, and the subject matter was recorded as belonging to 1 of the 11 ophthalmic subspecialties. After the content of the article was assigned, then the study design was recorded as one of the following: nonanalytic study, case-control or cohort study, randomized control trial, meta-analysis, laboratory science article, or systemic review. Subspecialty of the article and the study design used. Seven journals were included, and 12 426 abstracts were reviewed. Articles relating to medical retina were the most prevalent (29.1%), and those relating to strabismus were the least prevalent (2.3%). Case-control or cohort studies comprised most study designs (40.1%), with meta-analyses comprising the least (0.3%). The mean number of articles per year was 2485 (standard deviation, 125.1), remaining stable over the study period. Medical retina articles were significantly more common in 2009 than in 2005 (chi-square, 11.2; P = 0.0008), whereas the proportion of oculoplastic articles was significantly reduced (chi-square, 16.9; P<0.0001). Cataract and refractive surgery had the highest proportions of articles using the higher forms of study design (7.8%), and oculoplastics had the highest proportion of nonanalytic studies (64.5%). There are great differences across the specialty of ophthalmology in the subject matter of published literature, probably driven by recent

Ophthalmic Start-Up Chief Executive Officers' Perceptions of Development Hurdles.

Science.gov (United States)

Stewart, William C; Nelson, Lindsay A; Kruft, Bonnie; Stewart, Jeanette A

2018-01-01

To identify current challenges facing ophthalmic pharmaceutical start-ups in developing new products. Surveys were distributed to the chief executive officer (CEO) or president of ophthalmic start-ups. The survey attracted 24 responses from 78 surveys distributed (31%). The CEOs stated that a lack of financial capital (n = 18, 75%), FDA regulations (n = 6, 25%), and failure to meet clinical endpoints (n = 6, 25%) were their greatest development hurdles. Risk aversion to medicines in early development (n = 18, 75%), mergers and acquisitions reducing corporate choice for licensing agreements (n = 7, 29%), the emergence of large pharmaceutical-based venture capital funding groups (n = 12, 50%), and the failure of many large pharmaceutical companies to develop their own medicines (n = 10, 42%) were noted as recent prominent trends affecting fundraising. The study suggests that development funding, regulatory burden, and meeting clinical endpoints are the greatest development challenges faced by ophthalmic start-up CEOs. © 2017 S. Karger AG, Basel.

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.

Formulation and stability of an extemporaneous 0.02% chlorhexidine digluconate ophthalmic solution

Directory of Open Access Journals (Sweden)

Shu-Chiao Lin

2015-12-01

Conclusion: The acetate-buffered 0.02% chlorhexidine digluconate ophthalmic solution stored in light-resistant high-density polyethylene eyedroppers demonstrated excellent stability at 2–25°C for 6 months after being sealed and for 1 month after opening. This finding will enable us to prepare 0.02% chlorhexidine digluconate ophthalmic solutions based on a doctor's prescription.

Engineering Aspergillus oryzae A-4 through the Chromosomal Insertion of Foreign Cellulase Expression Cassette to Improve Conversion of Cellulosic Biomass into Lipids

Science.gov (United States)

Shen, Qi; Ma, Junwei; Fu, Jianrong; Zhao, Yuhua

2014-01-01

A genetic modification scheme was designed for Aspergillus oryzae A-4, a natural cellulosic lipids producer, to enhance its lipid production from biomass by putting the spotlight on improving cellulase secretion. Four cellulase genes were separately expressed in A-4 under the control of hlyA promoter, with the help of the successful development of a chromosomal genetic manipulation system. Comparison of cellulase activities of PCR-positive transformants showed that these transformants integrated with celA gene and with celC gene had significantly (pcellulase gene in A2-2 and D1-B1 was subsequently investigated. It was noted that cellulase expression repressed biomass formation but enhanced lipid accumulation; whereas the inhibitory effect on cell growth would be shielded during cellulosic lipids production owing to the essential role of cellulase in substrate utilization. Different metabolic profiles also existed between A2-2 and D1-B1, which could be attributed to not only different transgene but also biological impacts of different integration. Overall, both simultaneous saccharification and lipid accumulation were enhanced in A2-2 and D1-B1, resulting in efficient conversion of cellulose into lipids. A regulation of cellulase secretion in natural cellulosic lipids producers could be a possible strategy to enhance its lipid production from lignocellulosic biomass. PMID:25251435

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

International Nuclear Information System (INIS)

Fu, Jiapeng; Pang, Zengyuan; Yang, Jie; Huang, Fenglin; Cai, Yibing; Wei, Qufu

2015-01-01

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

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.

High Dehumidification Performance of Amorphous Cellulose Composite Membranes prepared from Trimethylsilyl Cellulose

KAUST Repository

Puspasari, Tiara

2018-04-11

Cellulose is widely regarded as an environmentally friendly, natural and low cost material which can significantly contribute the sustainable economic growth. In this study, cellulose composite membranes were prepared via regeneration of trimethylsilyl cellulose (TMSC), an easily synthesized cellulose derivative. The amorphous hydrophilic feature of the regenerated cellulose enabled fast permeation of water vapour. The pore-free cellulose layer thickness was adjustable by the initial TMSC concentration and acted as an efficient gas barrier. As a result, a 5,000 GPU water vapour transmission rate (WVTR) at the highest ideal selectivity of 1.1 x 106 was achieved by the membranes spin coated from a 7% (w/w) TMSC solution. The membranes maintained a 4,000 GPU WVTR with selectivity of 1.1 x 104 in the mixed-gas experiments, surpassing the performances of the previously reported composite membranes. This study provides a simple way to not only produce high performance membranes but also to advance cellulose as a low-cost and sustainable membrane material for dehumidification applications.

Degradation of γ-irradiated cellulose by the accumulating culture of a cellulose bacterium

International Nuclear Information System (INIS)

Namsaraev, B.B.; Kuznetsova, E.A.; Termkhitarova, N.G.

1987-01-01

Possibility of degradation of γ-irradiated cellulose by the accumulating culture of an anaerobic cellulose bacterium has been investigated. Cellulose irradiation by γ-quanta (Co 60 ) 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

An international strategic plan to preserve and restore vision: four curricula of ophthalmic education.

Science.gov (United States)

Tso, Mark O M; Goldberg, Morton F; Lee, Andrew G; Selvarajah, Sivaguru; Parrish, Richard K; Zagorski, Zbigniew

2007-05-01

To highlight the four International Curricula of Ophthalmic Education developed by the Task Forces of the International Council of Ophthalmology, published in Klinische Monatsblätter für Augenheilkunde in November 2006. A global perspective of developing educational curricula as tools to improve eye care. Review of the experience and conclusions of the four international panels. The Task Force on Resident and Specialist Education developed a curriculum consisting of 15 topics in basic, standard, and advanced levels to provide flexibility of educational programs of the ophthalmic specialist in different locations across the world. The curricula were designed to be an educational tool to stimulate multiple levels of training of the ophthalmic specialist. The Task Force on Ophthalmic Education of Medical Students designed a curriculum covering 11 topics and provides illustrative materials for teachers and students. The Task Force strongly advocates the ophthalmology curriculum to be part of the core program of general medical schools education. The Task Force on Para-ophthalmic Vision Specialist Education developed a curriculum to highlight the importance of a team approach to eye care, consisting of ophthalmic specialists and paraophthalmic personnel to produce maximum efficiency. The Task Force on Continuing Medical Education (CME) designed a curriculum exploring the principles, elements, categories, and administration of CME activities in a variety of topics. These curricula shifted the traditional apprentice system of education to a curriculum-based training program in which goals, expectations, competencies, and technical training are defined to improve eye care worldwide.

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.... (4) Petrolatum, up to 100 percent. (5) White ointment, up to 100 percent. (6) White petrolatum, up to...

Liquid crystalline solutions of cellulose in phosphoric acid for preparing cellulose yarns

NARCIS (Netherlands)

Boerstoel, H.

2006-01-01

The presen thesis describes a new process for manufacturing high tenacity and high modulus cellulose yarns. A new direct solvent for cellulose has been discovered, leading to liquid crystalline solutions. This new solvent, superphosphoric acid, rapidly dissolves cellulose. These liquid crystalline

Absorbed doses to the main parts of eyeball due to use 90Sr + 90Y ophthalmic applicator

International Nuclear Information System (INIS)

Chen Lishu

1993-05-01

The ophthalmic radiotherapy dosimetry and some affecting factors are introduced. The distributions of absorbed doses to the main parts of a fresh eyeball such as the cornea, sclera, lens and anterior chamber, during the radiotherapy by using a 90 Sr + 90 Y ophthalmic applicator are presented. An tissue-equivalent extrapolation ionization chamber was used in the dose measurement. The reasonable doses during ophthalmic radiotherapy for different depths have been obtained. Therefore, the absorbed dose to the lens, the most sensitive organ, can be given. These data are useful for radiation protection in ophthalmic radiotherapy

Characterization of cellulose nanowhiskers

International Nuclear Information System (INIS)

Nascimento, Nayra R.; Pinheiro, Ivanei F.; Morales, Ana R.; Ravagnani, Sergio P.; Mei, Lucia

2015-01-01

Cellulose is the most abundant polymer earth. The cellulose nanowhiskers can be extracted from the cellulose. These have attracted attention for its use in nanostructured materials for various applications, such as nanocomposites, because they have peculiar characteristics, among them, high aspect ratio, biodegradability and excellent mechanical properties. This work aims to characterize cellulose nanowhiskers from microcrystalline cellulose. Therefore, these materials were characterized by X-ray diffraction (XRD) to assess the degree of crystallinity, infrared spectroscopy (FT-IR), transmission electron microscopy (TEM) to the morphology of nanowhiskers and thermal stability was evaluated by Thermogravimetric Analysis (TGA). (author)

Effect of textured eye drop bottles on the photostability of pranoprofen 0.1% ophthalmic solution.

Science.gov (United States)

Iwatsuka, Kinya; Inada, Katsuhiro; Ueoka, Hiroki; Otsuka, Tadashi; Maeda, Masaki; Yamaguchi, Masazumi; Yasueda, Shin-ichi

2015-01-01

Ophthalmic solutions are usually filled in a plastic bottle due to its durability and disposability. In Japan, photostability is one of the concerns for the quality control because an eye drop bottle must be a transparent container. The present work studied the effect of textured eye drop bottles on its light blocking to improve the photostability of ophthalmic solutions. We investigated the photostability of Pranoprofen ophthalmic solution filled in a variety of textured eye drop bottles. Pranoprofen content was analyzed by high-performance liquid chromatography and surface structure of textured eye drop bottles was evaluated by transmittance, calculated average roughness (Ra) and haze intensity. We observed that eye drop bottle which had greater than Ra value of 1.0 µm and haze intensity 62% clearly showed photostability improvement. This report is the first one which shows that photostability of ophthalmic solution is improved by using textured eye drop bottle. Moreover, this approach is a simple and effective method to improve the photostability. This method is available for not only various ophthalmic applications but also other liquid pharmaceuticals or food products.

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.

Superior ophthalmic vein enlargement and increased muscle index in dysthyroid optic neuropathy.

Science.gov (United States)

Lima, Breno da Rocha; Perry, Julian D

2013-01-01

To compare superior ophthalmic vein diameter and extraocular muscle index in patients with thyroid eye disease with or without optic neuropathy. High-resolution CT scan images of 40 orbits of 20 patients with history of thyroid eye disease (with or without optic neuropathy), who underwent orbital decompression surgery from January 2007 to November 2009, were retrospectively reviewed. Superior ophthalmic vein diameter was measured in coronal and axial planes. Extraocular muscle index was calculated according to the method proposed by Barrett et al. The clinical diagnosis of optic neuropathy was based on characteristic signs that included afferent pupillary defect, decreased visual acuity, visual field defects, and dyschromatopsia. Orbits were divided in 2 groups based on presence or absence of optic neuropathy. Superior ophthalmic vein diameter was significantly higher in orbits with concomitant optic neuropathy (mean 2.4 ± 0.4mm, p optic neuropathy (mean 57.9% ± 5.7%, p = 0.0002). Muscle index greater than 50% was present in all patients with dysthyroid optic neuropathy. This study suggests that patients with thyroid eye disease with enlarged superior ophthalmic vein and increased extraocular muscle index are more likely to have concomitant optic neuropathy.

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.

Superabsorbent hydrogel composite based on copolymer cellulose/poly (vinyl alcohol)/CNT

International Nuclear Information System (INIS)

Khoerunnisa, Fitri; Hendrawan,; Sonjaya, Yaya; Putri, Oceu Dwi

2016-01-01

Superabsorbent hydrogels are cross-linked hydrophilic polymers that can absorb and retain a large volume of water, saline solution, or physiological fluids. A distinctive superabsorbent hydrogel composite based on cellulose/ poly (vinyl alcohol)/ carbon nanotubes was successfully synthesized via the graft bio-copolymerization in an aqueous medium with glutaraldehide as a crosslinking agent. The effect of carbon nanotubes (CNT) on water absorption capacity and mechanical properties of superabsorbent composite were particularly investigated. The Fourier transform infrared spectra showed the evidence of copolymerization of hydrogel precursors as well as the interaction of CNT filler with the hydrogel matrices, as indicated by the shifting of peak intensity and position of several functional groups (O-H, C-H sp"3, C=O, C-N, C-O). The modification of hydrogel surface morphology and porosity owing to CNT insertion was also confirmed by scanning electron microscopy images. The CNT insertion improved the mechanical strength of superabsorbent hydrogel composites. Moreover, insertion of CNT into hydrogel matrix remarkably increased the swelling capacity of superabsorbent composites up to 840%. This huge water absorption capacity of hydrogel composites offers promising applications in development of superabsorbent polymers.

Superabsorbent hydrogel composite based on copolymer cellulose/poly (vinyl alcohol)/CNT

Energy Technology Data Exchange (ETDEWEB)

Khoerunnisa, Fitri, E-mail: fitri.khoerunnisa@gmail.com; Hendrawan,; Sonjaya, Yaya; Putri, Oceu Dwi [Department of Chemistry, Indonesia University of Education, Setiabudi 229 Bandung, West Java, Indonesia 40154 (Indonesia)

2016-04-19

Superabsorbent hydrogels are cross-linked hydrophilic polymers that can absorb and retain a large volume of water, saline solution, or physiological fluids. A distinctive superabsorbent hydrogel composite based on cellulose/ poly (vinyl alcohol)/ carbon nanotubes was successfully synthesized via the graft bio-copolymerization in an aqueous medium with glutaraldehide as a crosslinking agent. The effect of carbon nanotubes (CNT) on water absorption capacity and mechanical properties of superabsorbent composite were particularly investigated. The Fourier transform infrared spectra showed the evidence of copolymerization of hydrogel precursors as well as the interaction of CNT filler with the hydrogel matrices, as indicated by the shifting of peak intensity and position of several functional groups (O-H, C-H sp{sup 3}, C=O, C-N, C-O). The modification of hydrogel surface morphology and porosity owing to CNT insertion was also confirmed by scanning electron microscopy images. The CNT insertion improved the mechanical strength of superabsorbent hydrogel composites. Moreover, insertion of CNT into hydrogel matrix remarkably increased the swelling capacity of superabsorbent composites up to 840%. This huge water absorption capacity of hydrogel composites offers promising applications in development of superabsorbent polymers.

Radioactivity measurements for some ophthalmic glasses

International Nuclear Information System (INIS)

Badawy, W.M.; Ali, E.M.; Gomaa, M.A.; Hussein, A

2007-01-01

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 2l4 Pb (352 keV), 212 Pb (238 keV) and 1460 keV gamma line for 40 K 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

Effects of viscoelastic ophthalmic solutions on cell cultures

Directory of Open Access Journals (Sweden)

Madhavan Hajib

1998-01-01

Full Text Available The development of mild but significant inflammation probably attributable to viscoelastic ophthalmic solutions in cataract surgery was recently brought to the notice of the authors, and hence a study of the effects of these solutions available in India, on cell cultures was undertaken. We studied the effects of 6 viscoelastic ophthalmic solutions (2 sodium hyaluronate designated as A and B, and 4 hydroxypropylmethylcellulose designated as C, D, E and F on HeLa, Vero and BHK-21 cell lines in tissue culture microtitre plates using undiluted, 1:10 and 1:100 dilutions of the solutions, and in cover slip cultures using undiluted solutions. Phase contrast microscopic examination of the solutions was also done to determine the presence of floating particles. The products D and F produced cytotoxic changes in HeLa cell line and these products also showed the presence of floating particles under phase contrast microscopy. Other products did not have any adverse effects on the cell lines nor did they show floating particles. The viscoelastic ophthalmic pharmaceutical products designated D and F have cytotoxic effects on HeLa cell line which appears to be a useful cell line for testing these products for their toxicity. The presence of particulate materials in products D and F indicates that the methods used for purification of the solution are not effective.

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....2 to 1 percent. (5) Propylene glycol, 0.2 to 1 percent. (e) Polyvinyl alcohol, 0.1 to 4 percent. (f...

Ophthalmic implications of seasonal affective disorder

International Nuclear Information System (INIS)

Paramore, J.E.; King, V.M.

1989-01-01

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

[Tibolone's effect on retinal and ophthalmic arteries flowmetry].

Science.gov (United States)

Souza, Marco Aurélio Martins de; Geber, Selmo

2008-11-01

to evaluate the effect of tibolone use on doppler-velocimetric parameters of ophthalmic and retinal arteries. clinical, prospective, longitudinal, randomized, placebo-controlled, triple-blind study, in which among 100 menopausal women, 50 have used 2.5 mg of the active principle tibolone (Tib Group) and 50, placebo as a means to form the control-group (Plac Group). In the Tib Group, 44 of the 50 women returned after 84 days to finish the exams, and in the Plac Group, 47. The ophthalmic and retinal arteries were studied to determine the resistance index (RI), the pulsatility index (PI) and the systole/diastole ratio (S/D). Assessments have been done before and 84 days after medication. The t-Student test has been used for the comparison of means between the groups in independent samples, as well as for within-group comparisons in dependent samples. in both groups, the women's characteristics were similar in age, menopause duration, body mass index, arterial blood pressure, deliveries and cardiac rate. The Tib Group presented the following values in the ophthalmic artery: RI(pre)=0.71+/-0.05, RI(post)0.72+/-0.08 (p=0.43); PI(pre)=1.29+/-0.22, PI(post)=1.30+/-0.25 (p=0.4) and S/D(pre)=3.49+/-0.77, SD(post)=3.65+/-0.94 (p=0.32). In the retinal artery, the following values have been found: RI(pre)=0.67+/-0.09, RI(post)=0.69+/-0.10 (p=0.7); PI(pre)=1.20+/-0.29, PI(post)=1.22+/-0.3 (p=0.2) and SD(pre)=3.29+/-0.95, SD(post)=3.30+/-1.07 (p=0.3). Also, the tibolone and control groups did not show any significant difference in regard to the above indexes in the end of the study. the 2.5 mg dose of tibolone had no effect on the Doppler velocimetry indexes of the ophthalmic and retinal arteries.

Recent Strategies in Preparation of Cellulose Nanocrystals and Cellulose Nanofibrils Derived from Raw Cellulose Materials

Directory of Open Access Journals (Sweden)

Hongxiang Xie

2018-01-01

Full Text Available The recent strategies in preparation of cellulose nanocrystals (CNCs and cellulose nanofibrils (CNFs were described. CNCs and CNFs are two types of nanocelluloses (NCs, and they possess various superior properties, such as large specific surface area, high tensile strength and stiffness, low density, and low thermal expansion coefficient. Due to various applications in biomedical engineering, food, sensor, packaging, and so on, there are many studies conducted on CNCs and CNFs. In this review, various methods of preparation of CNCs and CNFs are summarized, including mechanical, chemical, and biological methods. The methods of pretreatment of cellulose are described in view of the benefits to fibrillation.

[Biological availability of ophthalmic drugs. 1. Increasing drug permeability in the cornea].

Science.gov (United States)

Masteiková, R; Chalupová, Z; Savickiene, N

2004-03-01

Most eye diseases are treated by topical administration of ophthalmic preparations. Low ophthalmic bioavailability is due to a number of physiological and physicochemical factors. The main obstacle to the penetration of active ingredients to the eye is the layered character of the cornea. Formulation of ophthalmic preparations enabling easier penetration of this biological barrier thus ranks among the most effective ways of improving bioavailability. Penetrability of the cornea can be increased by the following methods: a) adjustment of the actual acidity in such a way that pH of the preparation makes it possible to produce the optimal portion of non-ionized particles; b) incorporation of absorption enhancers (non-ionic tensides, salts of bile acids, some antimicrobial substances, EDTA, cyclodextrins, etc.) into the composition of the preparation, and c) production of prodrugs or ionic pairs.

Versatile High-Performance Regenerated Cellulose Membranes Prepared using Trimethylsilyl Cellulose as a Precursor

KAUST Repository

Puspasari, Tiara

2018-01-01

(TMSC), a highly soluble cellulose derivative, as a precursor for the fabrication of cellulose thin film composite membranes. TMSC is an attractive precursor to assemble thin cellulose films with good deposition behavior and film morphology; cumbersome

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.)

Long-term results of treatment with diquafosol ophthalmic solution for aqueous-deficient dry eye.

Science.gov (United States)

Koh, Shizuka; Ikeda, Chikako; Takai, Yoshihiro; Watanabe, Hitoshi; Maeda, Naoyuki; Nishida, Kohji

2013-09-01

To evaluate the preliminary long-term efficacy of diquafosol ophthalmic solution for aqueous-deficient dry eye. Fifteen patients with mild-to-moderate aqueous-deficient dry eye were enrolled. After a washout period, the patients were treated with 3 % diquafosol ophthalmic solution for 6 months. We assessed 12 subjective dry eye symptoms, corneal and conjunctival staining with fluorescein, tear film break-up time (BUT), lower tear meniscus height measured with anterior-segment optical coherence tomography, Schirmer's testing, and adverse reactions at baseline and 1, 3, and 6 months after the start of treatment. Treatment with diquafosol ophthalmic solution significantly improved dry eye symptoms, corneal staining, BUT, and tear meniscus height at 1 month and maintained the effectiveness for 6 months. Conjunctival staining significantly improved 3 and 6 months after treatment. No significant adverse reactions developed. Prolonged use of diquafosol ophthalmic solution for 6 months produced significant improvement both subjectively (dry eye symptom score) and objectively (ocular staining score and tear function tests) for aqueous-deficient dry eye.

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.

Ophthalmic plastic and orbital surgery in Taiwan.

Science.gov (United States)

Hsu, Chi-Hsin; Lin, I-Chan; Shen, Yun-Dun; Hsu, Wen-Ming

2014-06-01

We describe in this paper the current status of ophthalmic plastic and orbital surgery in Taiwan. Data were collected from the Bureau of National Health Insurance of Taiwan, the Bulletin of the Taiwan Ophthalmic Plastic and Reconstructive Society, and the Statistics Yearbook of Practicing Physicians and Health Care Organizations in Taiwan by the Taiwan Medical Association. We ascertained that 94 ophthalmologists were oculoplastic surgeons and accounted for 5.8% of 1621 ophthalmologists in Taiwan. They had their fellowship training abroad (most ophthalmologists trained in the United States of America) or in Taiwan. All ophthalmologists were well trained and capable of performing major oculoplastic surgeries. The payment rates by our National Health Insurance for oculoplastic and orbital surgeries are relatively low, compared to Medicare payments in the United States. Ophthalmologists should promote the concept that oculoplastic surgeons specialize in periorbital plastic and aesthetic surgeries. However, general ophthalmologists should receive more educational courses on oculoplastic and cosmetic surgery. Copyright © 2014. Published by Elsevier B.V.

Drug-loaded Cellulose Acetate and Cellulose Acetate Butyrate Films ...

African Journals Online (AJOL)

The purpose of this research work was to evaluate the contribution of formulation variables on release properties of matrix type ocular films containing chloramphenicol as a model drug. This study investigated the use of cellulose acetate and cellulose acetate butyrate as film-forming agents in development of ocular films.

Development and Effects of FTY720 Ophthalmic Solution on Corneal Allograft Survival

OpenAIRE

Zhaochuan Liu; Haotian Lin; Chulong Huang; Wan Chen; Wu Xiang; Yu Geng; Weirong Chen

2015-01-01

Fingolimod (FTY720), a novel class of sphingosine 1-phosphate receptor modulators, has received special interest among ophthalmologists, particularly given that oral administration of FTY720 has proven to effectively treat corneal graft rejection in animal models. However, no studies have examined the performance of FTY720 as an ophthalmic solution in reducing corneal rejection in high-risk corneal rejection models, and the stability and ocular irritation profile of FTY720 ophthalmic solution...

Investigation of size effect on film type haptic actuator made with cellulose acetate

International Nuclear Information System (INIS)

Kim, Sang-Youn; Kim, Jaehwan; Kim, Ki-Baek

2014-01-01

The most important factor in haptic interaction with hand-held devices is to develop a thin film type actuator which can be easily inserted into the devices and create vibrotactile signals with wide frequency bandwidth. This paper reports a film type vibrotactile actuator which is tiny enough to be embedded into small hand-held devices. The vibration mechanism and experiment results for the suggested vibrotactile actuator are explained. The aim of the actuator is to convey a vibrotactile force greater than a human’s vibrotactile threshold with broad frequency bandwidth to users. To achieve the requirement, we fabricate a film type vibrotactile actuator with cellulose acetate. When an AC voltage is applied to the actuator, the cellulose acetate film gets charged and then generates vibration. The suggested vibrotactile actuator is fabricated in two sizes: 50 mm × 25 mm and 25 mm × 25 mm. For each size of actuator, three kinds of actuator are fabricated with different pillar materials to support the cellulose acetate films. An experiment for measuring vibrational amplitude is conducted over a wide frequency range of actuation voltage. It is known that the proposed film type actuator is feasible for haptic application in the small hand-held devices. (paper)

Brittle Culm1, a COBRA-Like Protein, Functions in Cellulose Assembly through Binding Cellulose Microfibrils

Science.gov (United States)

Zhang, Baocai; Liu, Xiangling; Yan, Meixian; Zhang, Lanjun; Shi, Yanyun; Zhang, Mu; Qian, Qian; Li, Jiayang; Zhou, Yihua

2013-01-01

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. PMID:23990797

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.

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

Science.gov (United States)

Liu, Lifeng; Shang-Guan, Keke; Zhang, Baocai; Liu, Xiangling; Yan, Meixian; Zhang, Lanjun; Shi, Yanyun; Zhang, Mu; Qian, Qian; Li, Jiayang; Zhou, Yihua

2013-01-01

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.

Ophthalmic examination in early diagnosis of Alzheimer's disease

Directory of Open Access Journals (Sweden)

Xin Li

2018-02-01

Full Text Available Alzheimer's disease is a progressive neurodegenerative disorder causing irreversible deterioration in memory and loss of self-care ability, which is seriously affecting the quality of life. There is no cure for Alzheimer's disease. Medication only can control the progression of the disease. Early diagnosis and control of disease progress is of great significance in improving the quality of life of the patients and reducing the burden of family and society. Ophthalmic examination is seen as a window which can “see” brain directly, and some changes in the eye can reflect the changes of the brain most directly. This paper reviews the ophthalmic examination of Alzheimer's disease, including optical coherence tomography(OCT, visual field, contrast sensitivity and eye movements, et al. We hope to provide a new idea for the early diagnosis of Alzheimer's disease.

Postoperative pain in complex ophthalmic surgical procedures: comparing practice with guidelines.

Science.gov (United States)

Lesin, Mladen; Sundov, Zeljka Duplancic; Jukic, Marko; Puljak, Livia

2014-06-01

To analyze the management of postoperative pain after complex ophthalmic surgery and to compare it to the guidelines. A retrospective study. University Hospital Split, Croatia. Patients (N = 447) who underwent complex ophthalmic surgical procedures from 2008 to 2012. The following data were extracted from patient medical records: age, gender, type and dosage of premedication, preoperative patient's physical status, type of procedure, duration of procedure-surgical and anesthesia time, type and dosage of anesthesia, the type and dosage of postoperative analgesia for each postoperative day. None of the patients had information about pain intensity in their records. There were 90% patients who did not receive any medication the night before surgery, 54% did not receive any premedication immediately before surgery, 19% did not receive any pain medication after the surgery in the operating room and 46% of patients did not receive any analgesics after being released to the ophthalmology department. Among those who received analgesia after surgery, 98% received only one dose of an analgesic, and 93% of patients received analgesia only on the day of the surgery. Furthermore, patients were returned to the department immediately after surgery, without intensive monitoring. During the analyzed five years there were no educational session organized by anesthesiologist to the ophthalmic surgeons. Postoperative pain management and perioperative care of patients undergoing major ophthalmic surgery indicates lack of attention towards pain intensity and postoperative analgesia. Appropriate interventions should be employed to improve postoperative pain management, to facilitate patient recovery. Wiley Periodicals, Inc.

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

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.

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.

Identification and Characterization of Non-Cellulose-Producing Mutants of Gluconacetobacter hansenii Generated by Tn5 Transposon Mutagenesis

Science.gov (United States)

Deng, Ying; Nagachar, Nivedita; Xiao, Chaowen; Tien, Ming

2013-01-01

The acs operon of Gluconacetobacter is thought to encode AcsA, AcsB, AcsC, and AcsD proteins that constitute the cellulose synthase complex, required for the synthesis and secretion of crystalline cellulose microfibrils. A few other genes have been shown to be involved in this process, but their precise role is unclear. We report here the use of Tn5 transposon insertion mutagenesis to identify and characterize six non-cellulose-producing (Cel−) mutants of Gluconacetobacter hansenii ATCC 23769. The genes disrupted were acsA, acsC, ccpAx (encoding cellulose-complementing protein [the subscript “Ax” indicates genes from organisms formerly classified as Acetobacter xylinum]), dgc1 (encoding guanylate dicyclase), and crp-fnr (encoding a cyclic AMP receptor protein/fumarate nitrate reductase transcriptional regulator). Protein blot analysis revealed that (i) AcsB and AcsC were absent in the acsA mutant, (ii) the levels of AcsB and AcsC were significantly reduced in the ccpAx mutant, and (iii) the level of AcsD was not affected in any of the Cel− mutants. Promoter analysis showed that the acs operon does not include acsD, unlike the organization of the acs operon of several strains of closely related Gluconacetobacter xylinus. Complementation experiments confirmed that the gene disrupted in each Cel− mutant was responsible for the phenotype. Quantitative real-time PCR and protein blotting results suggest that the transcription of bglAx (encoding β-glucosidase and located immediately downstream from acsD) was strongly dependent on Crp/Fnr. A bglAx knockout mutant, generated via homologous recombination, produced only ∼16% of the wild-type cellulose level. Since the crp-fnr mutant did not produce any cellulose, Crp/Fnr may regulate the expression of other gene(s) involved in cellulose biosynthesis. PMID:24013627

A co-production of sugars, lignosulfonates, cellulose, and cellulose nanocrystals from ball-milled woods.

Science.gov (United States)

Du, Lanxing; Wang, Jinwu; Zhang, Yang; Qi, Chusheng; Wolcott, Michael P; Yu, Zhiming

2017-08-01

This study demonstrated the technical potential for the large-scale co-production of sugars, lignosulfonates, cellulose, and cellulose nanocrystals. Ball-milled woods with two particle sizes were prepared by ball milling for 80min or 120min (BMW 80 , BMW 120 ) and then enzymatically hydrolyzed. 78.3% cellulose conversion of BMW 120 was achieved, which was three times as high as the conversion of BMW 80 . The hydrolyzed residues (HRs) were neutrally sulfonated cooking. 57.72g/L and 88.16g/L lignosulfonate concentration, respectively, were harvested from HR 80 and HR 120 , and 42.6±0.5% lignin were removed. The subsequent solid residuals were purified to produce cellulose and then this material was acid-hydrolyzed to produce cellulose nanocrystals. The BMW 120 maintained smaller particle size and aspect ratio during each step of during the multiple processes, while the average aspect ratio of its cellulose nanocrystals was larger. The crystallinity of both materials increased with each step of wet processing, reaching to 74% for the cellulose. Copyright © 2017 Elsevier Ltd. All rights reserved.

Versatile High-Performance Regenerated Cellulose Membranes Prepared using Trimethylsilyl Cellulose as a Precursor

KAUST Repository

Puspasari, Tiara

2018-05-01

Cellulose has emerged as an indispensable membrane material due to its abundant availability, low cost, fascinating physiochemical properties and environment benignancy. However, it is believed that the potential of this polymer is not fully explored yet due to its insolubility in the common organic solvents, encouraging the use of derivatization-regeneration method as a viable alternative to the direct dissolution in exotic or reactive solvents. In this work, we use trimethylsilyl cellulose (TMSC), a highly soluble cellulose derivative, as a precursor for the fabrication of cellulose thin film composite membranes. TMSC is an attractive precursor to assemble thin cellulose films with good deposition behavior and film morphology; cumbersome solvents used in the one step cellulose processing are avoided. This derivative is prepared from cellulose by the known silylation reaction. The complete transformation of TMSC back into cellulose after the membrane formation is carried out by vapor-phase acid treatment, which is simple, scalable and reproducible. This process along with the initial TMSC concentration determines the membrane sieving characteristics. Unlike the typical regenerated cellulose membranes with meso- or macropores, membranes regenerated from TMSC display micropores suitable for the selective separation of nanomolecules in aqueous and organic solvent nanofiltration. The membranes introduced in this thesis represent the first polymeric membranes ever reported for highly selective separation of similarly sized small organic molecules based on charge and size differences with outstanding fluxes. Owing to its strong hydrophilic and amorphous character, the membranes also demonstrate excellent air-dehumidification performance as compared to previously reported thin film composite membranes. Moreover, the use of TMSC enables the creation of the previously unfeasible cellulose–polydimethylsiloxane (PDMS) and cellulose–polyethyleneimine (PEI) blend membranes

Physicochemical analysis of cellulose from microalgae ...

African Journals Online (AJOL)

USER

2016-06-15

Jun 15, 2016 ... The extraction method of algae cellulose was a modification of ... triplicate. Characterization of cellulose. Analysis of ... The current analysis of the cellulose extracted .... Cellulose nanomaterials review: structure, properties and.

Comparison of the effects of ophthalmic solutions on human corneal epithelial cells using fluorescent dyes.

Science.gov (United States)

Xu, Manlong; Sivak, Jacob G; McCanna, David J

2013-11-01

To investigate the effect of differently preserved ophthalmic solutions on the viability and barrier function of human corneal epithelial cells (HCEC) using fluorescent dyes. HCEC monolayers were exposed to the ophthalmic solutions containing benzalkonium chloride (BAK), edetate disodium, polyquad, stabilized oxychloro complex (Purite), sodium perborate, or sorbic acid for 5 min, 15 min, and 1 h. At 24 h after exposure, the cultures were assessed for metabolic activity using alamarBlue. The enzyme activity, membrane integrity, and apoptosis were evaluated using confocal microscopy. Barrier function was assessed using sodium fluorescein. The metabolic assay showed that the BAK-preserved ophthalmic solutions significantly reduced cell viability after a 5-min exposure compared to the phosphate buffered saline treated control (POphthalmic solutions with new preservatives had varying time-dependent adverse effects on cell viability, and the preservative-free solution had the least effect on HCEC. Sodium fluorescein permeability showed that HCEC monolayers treated with BAK-preserved solutions were more permeable to sodium fluorescein than those treated by the other ophthalmic solutions (Psolutions had greater adverse effects on metabolic activity, enzyme activity, membrane integrity, cell viability, and barrier function than the solutions that were not preserved with BAK. Our study suggests that BAK-free especially, preservative-free ophthalmic solutions are safer alternatives to BAK-preserved ones.

Optimizing Extraction of Cellulose and Synthesizing Pharmaceutical Grade Carboxymethyl Sago Cellulose from Malaysian Sago Pulp

Directory of Open Access Journals (Sweden)

Anand Kumar Veeramachineni

2016-06-01

Full Text Available Sago biomass is an agro-industrial waste produced in large quantities, mainly in the Asia-Pacific region and in particular South-East Asia. This work focuses on using sago biomass to obtain cellulose as the raw material, through chemical processing using acid hydrolysis, alkaline extraction, chlorination and bleaching, finally converting the material to pharmaceutical grade carboxymethyl sago cellulose (CMSC by carboxymethylation. The cellulose was evaluated using Thermogravimetric Analysis (TGA, Infrared Spectroscopy (FTIR, X-Ray Diffraction (XRD, Differential Scanning Calorimetry (DSC and Field Emission Scanning Electronic Microscopy (FESEM. The extracted cellulose was analyzed for cellulose composition, and subsequently modified to CMSC with a degree of substitution (DS 0.6 by typical carboxymethylation reactions. X-ray diffraction analysis indicated that the crystallinity of the sago cellulose was reduced after carboxymethylation. FTIR and NMR studies indicate that the hydroxyl groups of the cellulose fibers were etherified through carboxymethylation to produce CMSC. Further characterization of the cellulose and CMSC were performed using FESEM and DSC. The purity of CMSC was analyzed according to the American Society for Testing and Materials (ASTM International standards. In this case, acid and alkaline treatments coupled with high-pressure defibrillation were found to be effective in depolymerization and defibrillation of the cellulose fibers. The synthesized CMSC also shows no toxicity in the cell line studies and could be exploited as a pharmaceutical excipient.

Audit of patients' awareness of ophthalmic diagnoses.

Science.gov (United States)

Sudesh, S; Downes, S M; McDonnell, P J

1993-09-01

Providing information to patients about their medical condition and treatment options is important in medical management. To assess patients' knowledge of their ocular disease, prognosis, and treatment a questionnaire based survey was performed. 219 patients selected by random systematic sampling during six months from patients attending general ophthalmic clinics in Selly Oak Hospital, Birmingham, were questioned and 217 questionnaires were analysed. The findings showed that patients' knowledge of their diagnosis depended on their condition: patients with common conditions such as glaucoma and cataract had a better understanding of their condition, its treatment, and prognosis compared with patients with rarer conditions such as retinal detachment or patients with multiple diagnoses. In all, 152 patients (70%) wanted more information about their condition; 49 (23%) did not (although 12 (25%) had attempted to obtain information); and 16 (7%) were undecided. In view of the few patients with a precise understanding of their ophthalmic diagnosis and prognosis and the majority's wish for access to further information, that access needs improvement and different modes of disseminating the information should be implemented.

Pulsed UV laser technologies for ophthalmic surgery

International Nuclear Information System (INIS)

Razhev, A M; Bagayev, S N; Churkin, D S; Kargapol’tsev, E S; Chernykh, V V; Iskakov, I A; Ermakova, O V

2017-01-01

The paper provides an overview of the results of multiyear joint researches of team of collaborators of Institute of Laser Physics SB RAS together with NF IRTC “Eye Microsurgery” for the period from 1988 to the present, in which were first proposed and experimentally realized laser medical technologies for correction of refractive errors of known today as LASIK, the treatment of ophthalmic herpes and open-angle glaucoma. It is proposed to carry out operations for the correction of refractive errors the use of UV excimer KrCl laser with a wavelength of 222 nm. The same laser emission is the most suitable for the treatment of ophthalmic herpes, because it has a high clinical effect, combined with many years of absence of recrudescence. A minimally invasive technique of glaucoma operations using excimer XeCl laser (λ=308 nm) is developed. Its wavelength allows perform all stages of glaucoma operations, while the laser head itself has high stability and lifetime, will significantly reduce operating costs, compared with other types of lasers. (paper)

Pediatric ophthalmic indications for examination under anesthesia in ...

African Journals Online (AJOL)

Objective: To determine the ophthalmic indications and challenges for pediatric ocular examination under anesthesia (EUA). Methods: The surgical register and patients' records of children who underwent EUA between 1990 and 2007 were examined to document patients' bio data, diagnoses and details of procedures and ...

A new human eye model for ophthalmic brachytherapy dosimetry

International Nuclear Information System (INIS)

Yoriyaz, H.; Sanchez, A.; Dos Santos, A.

2005-01-01

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 125 I seeds and 60 Co 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)

A Molecular Description of Cellulose Biosynthesis

Science.gov (United States)

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

2016-01-01

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 which it is synthesized is now only beginning to emerge. On the basis of recent advances in structural and molecular biology on bacterial cellulose synthases, we review emerging concepts of how the enzymes polymerize glucose molecules, how the nascent polymer is transported across the plasma membrane, and how bacterial cellulose biosynthesis is regulated during biofilm formation. Additionally, we review evolutionary commonalities and differences between cellulose synthases that modulate the nature of the cellulose product formed. PMID:26034894

Regiocontroll synthesis cellulose-graft-polycaprolactone copolymer (2,3-di-O-PCL-cellulose by a new route

Directory of Open Access Journals (Sweden)

K. L. Wang

2017-12-01

Full Text Available A new and convenient route to the regiocontrolled synthesis of a cellulose-based derivate copolymer (2,3-di-O-polycaprolactone-cellulose grafting ε-caprolactone (ε-CL from α-cellulose, cellulose-graft-polycaprolactone (cellulose-g-PCL, by a classical ring-opening polymerization (ROP reaction, using stannous octoate (Sn(Oct2 as catalyst, in 68% concentration of zinc chloride aqueous solution at 120 °C was presented. By controlling the hydroxyl of cellulose/ε-CL, catalyst/monomer ratio and the reaction time, the molecular architecture of the copolymers can be altered. The solubility of cellulose in zinc chloride aqueous was indicated by UV/VIS spectrometer and rheological measurements. The structures and thermal properties of cellulose-g-polycaprolactone copolymers were characterized using Fourier Transform Infrared (FT-IR, Proton Nuclear Magnetic Resonance Spectroscopy (1H NMR, X-ray Diffraction (XRD, Thermogravimetric Analysis (TGA, Differential Scanning Calorimetry (DSC and Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES. The interesting results confirm that zinc chloride solution can break the intra-molecular hydrogen bonds of cellulose selectively (not only O3H···O5, but also O2H···O6, and has no effect on the inter-molecular hydrogen bonds (O6H···O3. And the grafting reactivity of hydroxyl on cellulose is C2–OH > C3–OH >> C6–OH in zinc chloride solution, and this is clearly different from other researches. Most importantly, this work confirms that the method to regiocontrolled synthesis cellulose-based derivative polymers by regiobreaking hydrogen bonds is feasible. It is strongly believed that the new discovery may give a novel, environmental, simple and inexpensive method to modify cellulose chemically with various side chains grafted on a given hydroxyl, through liberating hydroxyl as reactive group from hydrogen bonds broken selectively by different solvents.

High Dehumidification Performance of Amorphous Cellulose Composite Membranes prepared from Trimethylsilyl Cellulose

KAUST Repository

Puspasari, Tiara; Akhtar, Faheem Hassan; Ogieglo, Wojciech; Alharbi, Ohoud; Peinemann, Klaus-Viktor

2018-01-01

Cellulose is widely regarded as an environmentally friendly, natural and low cost material which can significantly contribute the sustainable economic growth. In this study, cellulose composite membranes were prepared via regeneration

Preparation of cellulose II and IIII films by allomorphic conversion of bacterial cellulose I pellicles

International Nuclear Information System (INIS)

Faria-Tischer, Paula C.S.; Tischer, Cesar A.; Heux, Laurent; Le Denmat, Simon; Picart, Catherine; Sierakowski, Maria-R.

2015-01-01

The structural changes resulting from the conversion of native cellulose I (Cel I) into allomorphs II (Cel II) and III I (Cel III I ) 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 III I 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 III I 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

Cytotoxicity of ophthalmic solutions with and without preservatives to human corneal endothelial cells, epithelial cells and conjunctival epithelial cells.

Science.gov (United States)

Ayaki, Masahiko; Yaguchi, Shigeo; Iwasawa, Atsuo; Koide, Ryohei

2008-08-01

The cytotoxicity of a range of commercial ophthalmic solutions in the presence and absence of preservatives was assessed in human corneal endothelial cells (HCECs), corneal epithelia and conjunctival epithelia using in vitro techniques. Cell survival was measured using the WST-1 assay for endothelial cells and the MTT assay for epithelial cells. Commercially available timolol, carteolol, cromoglicate, diclofenac, bromfenac and hyaluronic acid ophthalmic solutions were assessed for cytotoxicity in the presence and absence of preservatives. The preservatives benzalkonium, chlorobutanol and polysorbate were also tested. The survival of cells exposed to test ophthalmic solutions was expressed as a percentage of cell survival in the control solution (distilled water added to media) after 48 h exposure. HCEC survival was 20-30% in ophthalmic solutions diluted 10-fold. The survival of HCEC was significantly greater in all solutions in the absence of preservative than in the presence of preservative. The survival of corneal and conjunctival epithelia was consistent with that of HCECs for all test ophthalmic solutions. The preservatives polysorbate and benzalkonium were highly cytotoxic with cell survival decreasing to 20% at the concentration estimated in commercial ophthalmic solutions. By comparison, the survival of cells exposed to chlorobutanol was 80% or greater. The cytotoxicity of ophthalmic solutions to HCEC, corneal epithelia and conjunctival epithelia decreased in the absence of preservative.

Financial return-on-investment of ophthalmic interventions: a new paradigm.

Science.gov (United States)

Brown, Melissa M; Brown, Gary C; Lieske, Heidi B; Lieske, P Alexander

2014-05-01

Although the patient value gain (improvement in quality-of-life and/or length-of-life) has been highlighted in Value-based Medicine cost-utility analyses, the financial value gain associated with healthcare interventions has received less emphasis. It is important for professional healthcare providers to realize their interventions often confer a large financial return-on-investment (ROI) to society. The societal costs associated with vitreoretinal and other ophthalmic interventions include: direct ophthalmic medical costs expended (hospital, physician, drug, diagnostic testing and so forth), direct medical costs saved (decreased costs for depression, injury, skilled nursing facility, nursing home and others), direct nonmedical costs saved (decreased costs for caregivers, transportation, residence costs, moving costs, and others), and indirect medical costs saved (improving employment incidence and wages). The financial ROI for direct ophthalmic medical costs expended for ranibizumab therapy for neovascular age-related macular degeneration is 450%, whereas that for cataract surgery is 4500% and for medical open-angle glaucoma therapy is 4000%. Many costs gained add to the Gross Domestic Product and increase the wealth of the nation. Many vitreoretinal and other ophthalmologic interventions confer considerable patient value, but also result in a large financial ROI to society. This financial ROI increases the wealth of the nation.

Cellulose nanocrystal properties and their applications

Directory of Open Access Journals (Sweden)

mahdi jonoobi

2015-05-01

Full Text Available The main purpose of this work is to provide an overview of recent research in the area of cellulose nonmaterials production from different sources. Due to their abundance, their renewability, high strength and stiffness, being eco-friendly, and low weight; numerous studies have been reported on the isolation of cellulose nanomaterials from different cellulosic sources and their use in high performance applications. This work covers an introduction into the nano cellulose definition as well as used methods for isolation of nanomaterials (nanocrystals from various sources. The rod-like cellulose nanocrystals (CNC can be isolated from sources like wood, plant fibers, agriculture and industrial bio residues, tunicates, and bacterial cellulose using acid hydrolysis process. Following this, the paper focused on characterization methods, materials properties and structure. The current review is a comprehensive literature regarding the nano cellulose isolation and demonstrates the potential of cellulose nanomaterials to be used in a wide range of high-tech applications.

Polymorphy in native cellulose: recent developments

International Nuclear Information System (INIS)

Atalla, R.H.

1984-01-01

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 13 C-NMR studies. More recently, they have proposed, on the basis of high resolution solid-state 13 C-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 13 C-NMR investigations

Biochemistry of cellulose degradation and cellulose utilization for feeds and for protein

Energy Technology Data Exchange (ETDEWEB)

Sadara, J C; Lachke, A H; Shewale, J G

1979-01-01

A review discussing production of single-cell protein, fuel, and glucose from cellulose decomposition; surface or solid fermentations of single-cell protein; production of cellulases; and the biochemistry of cellulose degradation was presented.

All-cellulose composites of regenerated cellulose fibres by surface selective dissolution

NARCIS (Netherlands)

Soykeabkaew, N.; Nishino, T.; Peijs, Ton

2009-01-01

All-cellulose composites of Lyocell and high modulus/strength cellulose fibres were successfully prepared using a surface selective dissolution method. The effect of immersion time of the fibres in the solvent during composite's preparation and the effect of the starting fibre's structure on their

Evaluation of the cytotoxic effects of ophthalmic solutions containing benzalkonium chloride on corneal epithelium using an organotypic 3-D model.

Science.gov (United States)

Khoh-Reiter, Su; Jessen, Bart A

2009-07-28

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. 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 microL 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. 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. The lack of cytotoxicity demonstrated in 3-D corneal cultures and in monkey studies suggests that the levels of BAC contained in ophthalmic solutions are not likely to cause

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

21 CFR 524.390a - Chloramphenicol ophthalmic ointment.

Science.gov (United States)

2010-04-01

... (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS OPHTHALMIC AND TOPICAL DOSAGE FORM NEW ANIMAL DRUGS... treatment for 48 hours (2 days) after eye appears normal. Therapy for cats should not exceed 7 days... therapy should be considered. When infection may be cause of disease, especially in purulent or catarrhal...

Doppler sonographic evaluation of ophthalmic arterial flow pattern in hypertensive patients

International Nuclear Information System (INIS)

Ryu, Dae Sik; Kim, Young Goo

1994-01-01

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

Strong and Optically Transparent Films Prepared Using Cellulosic Solid Residue Recovered from Cellulose Nanocrystals Production Waste Stream

Science.gov (United States)

Qianqian Wang; J.Y. Zhu; John M. Considine

2013-01-01

We used a new cellulosic material, cellulosic solid residue (CSR), to produce cellulose nanofibrils (CNF) for potential high value applications. Cellulose nanofibrils (CNF) were produced from CSR recovered from the hydrolysates (waste stream) of acid hydrolysis of a bleached Eucalyptus kraft pulp (BEP) to produce nanocrystals (CNC). Acid hydrolysis greatly facilitated...

21 CFR 573.420 - Ethyl cellulose.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ethyl cellulose. 573.420 Section 573.420 Food and... Listing § 573.420 Ethyl cellulose. The food additive ethyl cellulose may be safely used in animal feed in accordance with the following prescribed conditions: (a) The food additive is a cellulose ether containing...

21 CFR 172.868 - Ethyl cellulose.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethyl cellulose. 172.868 Section 172.868 Food and... Multipurpose Additives § 172.868 Ethyl cellulose. The food additive ethyl cellulose may be safely used in food in accordance with the following prescribed conditions: (a) The food additive is a cellulose ether...

Optimization of upstream and development of cellulose hydrolysis process for cellulosic bio-ethanol production

Energy Technology Data Exchange (ETDEWEB)

Bae, Hyun Jong; Wi, Seung Gon; Kim, Su Bae; Shin, You Jung; Yi, Ju Hui [Chonnam National University, Bio-Energy Research Institute, Gwangju (Korea, Republic of)

2010-10-15

The purpose of this project is optimization of upstream and development of cellulose hydrolysis process for cellulosic bio-ethanol production. Research scope includes 1) screening of various microorganisms from decayed biomass in order to search for more efficient lignocellulose degrading microorganism, 2) identification and verification of new cell wall degrading cellulase for application cellulose bioconversion process, and 3) identification and characterization of novel genes involved in cellulose degradation. To find good microorganism candidates for lignocellulose degrading, 75 decayed samples from different areas were assayed in triplicate and analyzed. For cloning new cell wall degrading enzymes, we selected microorganisms because it have very good lignocellulose degradation ability. From that microorganisms, we have apparently cloned a new cellulase genes (10 genes). We are applying the new cloned cellulase genes to characterize in lignocellulsoe degradation that are most important to cellulosic biofuels production

Optimization of upstream and development of cellulose hydrolysis process for cellulosic bio-ethanol production

International Nuclear Information System (INIS)

Bae, Hyun Jong; Wi, Seung Gon; Kim, Su Bae; Shin, You Jung; Yi, Ju Hui

2010-10-01

The purpose of this project is optimization of upstream and development of cellulose hydrolysis process for cellulosic bio-ethanol production. Research scope includes 1) screening of various microorganisms from decayed biomass in order to search for more efficient lignocellulose degrading microorganism, 2) identification and verification of new cell wall degrading cellulase for application cellulose bioconversion process, and 3) identification and characterization of novel genes involved in cellulose degradation. To find good microorganism candidates for lignocellulose degrading, 75 decayed samples from different areas were assayed in triplicate and analyzed. For cloning new cell wall degrading enzymes, we selected microorganisms because it have very good lignocellulose degradation ability. From that microorganisms, we have apparently cloned a new cellulase genes (10 genes). We are applying the new cloned cellulase genes to characterize in lignocellulsoe degradation that are most important to cellulosic biofuels production

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),

Internally plasticised cellulose polymers

International Nuclear Information System (INIS)

Burnup, M.; Hayes, G.F.; Fydelor, P.J.

1981-01-01

Plasticised cellulose polymers comprise base polymer having a chain of β-anhydroglucose units joined by ether linkages, with at least one of said units carrying at least one chemically unreactive side chain derived from an allylic monomer or a vinyl substituted derivative of ferrocene. The side chains are normally formed by radiation grafting. These internally plasticised celluloses are useful in particular as inhibitor coatings for rocket motor propellants and in general wherever cellulose polymers are employed. (author)

Synthesis and Self-Assembly of Cellulose Microfibrils from Reconstituted Cellulose Synthase.

Science.gov (United States)

Cho, Sung Hyun; Purushotham, Pallinti; Fang, Chao; Maranas, Cassandra; Díaz-Moreno, Sara M; Bulone, Vincent; Zimmer, Jochen; Kumar, Manish; Nixon, B Tracy

2017-09-01

Cellulose, the major component of plant cell walls, can be converted to bioethanol and is thus highly studied. In plants, cellulose is produced by cellulose synthase, a processive family-2 glycosyltransferase. In plant cell walls, individual β-1,4-glucan chains polymerized by CesA are assembled into microfibrils that are frequently bundled into macrofibrils. An in vitro system in which cellulose is synthesized and assembled into fibrils would facilitate detailed study of this process. Here, we report the heterologous expression and partial purification of His-tagged CesA5 from Physcomitrella patens Immunoblot analysis and mass spectrometry confirmed enrichment of PpCesA5. The recombinant protein was functional when reconstituted into liposomes made from yeast total lipid extract. The functional studies included incorporation of radiolabeled Glc, linkage analysis, and imaging of cellulose microfibril formation using transmission electron microscopy. Several microfibrils were observed either inside or on the outer surface of proteoliposomes, and strikingly, several thinner fibrils formed ordered bundles that either covered the surfaces of proteoliposomes or were spawned from liposome surfaces. We also report this arrangement of fibrils made by proteoliposomes bearing CesA8 from hybrid aspen. These observations describe minimal systems of membrane-reconstituted CesAs that polymerize β-1,4-glucan chains that coalesce to form microfibrils and higher-ordered macrofibrils. How these micro- and macrofibrils relate to those found in primary and secondary plant cell walls is uncertain, but their presence enables further study of the mechanisms that govern the formation and assembly of fibrillar cellulosic structures and cell wall composites during or after the polymerization process controlled by CesA proteins. © 2017 American Society of Plant Biologists. All Rights Reserved.

New Zealand health reforms: effect on ophthalmic practice.

Science.gov (United States)

Raynel, S; Reynolds, H

1999-01-01

Are specialized ophthalmic units with inpatient facilities going to disappear in the New Zealand public health system? We have entered the era of cost containment, business methodologies, bench marking, day case surgery, and technologic advances. The dilemma for nursing is maintenance of a skill base with dwindling clinical practice areas.

Cellulose Nanomaterials in Water Treatment Technologies

Science.gov (United States)

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

2015-01-01

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

Cellulose nanomaterials in water treatment technologies.

Science.gov (United States)

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

2015-05-05

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.

Posidonia oceanica as a Renewable Lignocellulosic Biomass for the Synthesis of Cellulose Acetate and Glycidyl Methacrylate Grafted Cellulose

Directory of Open Access Journals (Sweden)

Elena Vismara

2013-05-01

Full Text Available High-grade cellulose (97% α-cellulose content of 48% crystallinity index was extracted from the renewable marine biomass waste Posidonia oceanica using H2O2 and organic peracids following an environmentally friendly and chlorine-free process. This cellulose appeared as a new high-grade cellulose of waste origin quite similar to the high-grade cellulose extracted from more noble starting materials like wood and cotton linters. The benefits of α-cellulose recovery from P. oceanica were enhanced by its transformation into cellulose acetate CA and cellulose derivative GMA-C. Fully acetylated CA was prepared by conventional acetylation method and easily transformed into a transparent film. GMA-C with a molar substitution (MS of 0.72 was produced by quenching Fenton’s reagent (H2O2/FeSO4 generated cellulose radicals with GMA. GMA grafting endowed high-grade cellulose from Posidonia with adsorption capability. GMA-C removes β-naphthol from water with an efficiency of 47%, as measured by UV-Vis spectroscopy. After hydrolysis of the glycidyl group to glycerol group, the modified GMA-C was able to remove p-nitrophenol from water with an efficiency of 92%, as measured by UV-Vis spectroscopy. α-cellulose and GMA-Cs from Posidonia waste can be considered as new materials of potential industrial and environmental interest.

Potassium fulvate-modified graft copolymer of acrylic acid onto cellulose as efficient chelating polymeric sorbent.

Science.gov (United States)

Mohamed, Magdy F; Essawy, Hisham A; Ammar, Nabila S; Ibrahim, Hanan S

2017-01-01

Acrylic acid (AA) was graft copolymerized from cellulose (Cell) in presence of potassium fulvate (KF) in order to enhance the chemical activity of the resulting chelating polymer and the handling as well. Fourier transform infrared (FTIR) proved that KF was efficiently inserted and became a permanent part of the network structure of the sorbent in parallel during the grafting copolymerization. Scanning electron microscopy (SEM) revealed intact homogeneous structure with uniform surface. This indicates improvement of the handling, however, it was not the case for the graft copolymer of acrylic acid onto cellulose in absence of KF, which is known to be brittle and lacks mechanical integrity. Effective insertion of this co-interpenetrating agent provided more functional groups, such as OH and COOH, which improved the chelating power of the produced sorbent as found for the removal of Cu 2+ ions from its aqueous solutions (the removal efficiency reached ∼98.9%). Different models were used to express the experimental data. The results corroborated conformity of the pseudo-second order kinetic model and Langmuir isotherm model to the sorption process, which translates into dominance of the chemisorption. Regeneration of the chelating polymers under harsh conditions did not affect the efficiency of copper ions uptake up to three successive cycles. A thermodynamic investigation ensured exothermic nature of the adsorption process that became less favourable at higher temperatures. Copyright © 2016 Elsevier B.V. All rights reserved.

Gatifloxacin Ophthalmic Solution for Treatment of Bacterial Conjunctivitis: Safety, Efficacy and Patient Perspective

OpenAIRE

Clyde Schultz

2012-01-01

Gatifloxacin is a fourth generation fluroquinolone antibiotic that has been prescribed for systemic use. However, the drug which was developed by Kyorin (Japan) was linked to toxic reactions and death and was banned in the United States and Canada for use as an oral dosage form. It continues to be used as a topical application for ophthalmic conditions as the systemic toxicity seen when taking the drug orally has not been observed with ophthalmic use. The available data indicate that ocular u...

Sticking to cellulose: exploiting Arabidopsis seed coat mucilage to understand cellulose biosynthesis and cell wall polysaccharide interactions.

Science.gov (United States)

Griffiths, Jonathan S; North, Helen M

2017-05-01

The cell wall defines the shape of cells and ultimately plant architecture. It provides mechanical resistance to osmotic pressure while still being malleable and allowing cells to grow and divide. These properties are determined by the different components of the wall and the interactions between them. The major components of the cell wall are the polysaccharides cellulose, hemicellulose and pectin. Cellulose biosynthesis has been extensively studied in Arabidopsis hypocotyls, and more recently in the mucilage-producing epidermal cells of the seed coat. The latter has emerged as an excellent system to study cellulose biosynthesis and the interactions between cellulose and other cell wall polymers. Here we review some of the major advances in our understanding of cellulose biosynthesis in the seed coat, and how mucilage has aided our understanding of the interactions between cellulose and other cell wall components required for wall cohesion. Recently, 10 genes involved in cellulose or hemicellulose biosynthesis in mucilage have been identified. These discoveries have helped to demonstrate that xylan side-chains on rhamnogalacturonan I act to link this pectin directly to cellulose. We also examine other factors that, either directly or indirectly, influence cellulose organization or crystallization in mucilage. © 2017 INRA. New Phytologist © 2017 New Phytologist Trust.

Cellulose ionics: switching ionic diode responses by surface charge in reconstituted cellulose films.

Science.gov (United States)

Aaronson, Barak D B; Wigmore, David; Johns, Marcus A; Scott, Janet L; Polikarpov, Igor; Marken, Frank

2017-09-25

Cellulose films as well as chitosan-modified cellulose films of approximately 5 μm thickness, reconstituted from ionic liquid media onto a poly(ethylene-terephthalate) (PET, 6 μm thickness) film with a 5, 10, 20, or 40 μm diameter laser-drilled microhole, show significant current rectification in aqueous NaCl. Reconstituted α-cellulose films provide "cationic diodes" (due to predominant cation conductivity) whereas chitosan-doped cellulose shows "anionic diode" effects (due to predominant anion conductivity). The current rectification, or "ionic diode" behaviour, is investigated as a function of NaCl concentration, pH, microhole diameter, and molecular weight of the chitosan dopant. Future applications are envisaged exploiting the surface charge induced switching of diode currents for signal amplification in sensing.

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

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.

Novel proton exchange membranes based on structure-optimized poly(ether ether ketone ketone)s and nanocrystalline cellulose

Science.gov (United States)

Ni, Chuangjiang; Wei, Yingcong; Zhao, Qi; Liu, Baijun; Sun, Zhaoyan; Gu, Yan; Zhang, Mingyao; Hu, Wei

2018-03-01

Two sulfonated fluorenyl-containing poly(ether ether ketone ketone)s (SFPEEKKs) were synthesized as the matrix of composite proton exchange membranes by directly sulfonating copolymer precursors comprising non-sulfonatable fluorinated segments and sulfonatable fluorenyl-containing segments. Surface-modified nanocrystalline cellulose (NCC) was produced as the "performance-enhancing" filler by treating the microcrystalline cellulose with acid. Two families of SFPEEKK/NCC nanocomposite membranes with various NCC contents were prepared via a solution-casting procedure. Results revealed that the insertion of NCC at a suitable ratio could greatly enhance the proton conductivity of the pristine membranes. For example, the proton conductivity of SFPEEKK-60/NCC-4 (SFPEEKK with 60% fluorenyl segments in the repeating unit, and inserted with 4% NCC) composite membrane was as high as 0.245 S cm-1 at 90 °C, which was 61.2% higher than that of the corresponding pure SFPEEKK-60 membrane. This effect could be attributed to the formation of hydrogen bond networks and proton conduction paths through the interaction between -SO3H/-OH groups on the surface of NCC particles and -SO3H groups on the SFPEEKK backbones. Furthermore, the chemically modified NCC filler and the optimized chemical structure of the SFPEEKK matrix also provided good dimensional stability and mechanical properties of the obtained nanocomposites. In conclusion, these novel nanocomposites can be promising proton exchange membranes for fuel cells at moderate temperatures.

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.

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.

Re-evaluation of Magnetic Resonance and Computerised Tomographic Imaging in Neuro-Ophthalmic Patients in an Academic Centre

NARCIS (Netherlands)

Koekoek, Clarence G. J.; Meiners, Linda C.; Pott, Jan Willem R.

The aim of the study is to report the frequency of missed diagnoses on magnetic resonance and computerised tomographic imaging in neuro-ophthalmic patients who were referred to an academic ophthalmology department, with apparent normal imaging. The authors included all neuro-ophthalmic patients,

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. © 2015 John Wiley & Sons Ltd.

Raman spectroscopy in the analysis of cellulose nanomaterials

Science.gov (United States)

Umesh P. Agarwal

2017-01-01

Cellulose nanomaterials (CNs) are new types of materials derived from celluloses and offer unique challenges and opportunities for Raman spectroscopic investigations. CNs can be classified into the categories of cellulose nanocrystals (CNCs, also known as cellulose whisker) and cellulose nanofibrils (CNFs, also known as nanofibrillated cellulose or NFCs) which when...

Extraction of cellulose from pistachio shell and physical and mechanical characterisation of cellulose-based nanocomposites

Science.gov (United States)

Movva, Mounika; Kommineni, Ravindra

2017-04-01

Cellulose is an important nanoentity that have been used for the preparation of composites. The present work focuses on the extraction of cellulose from pistachio shell and preparing a partially degradable nanocomposite with extracted cellulose. Physical and microstructural characteristics of nanocellulose extracted from pistachio shell powder (PSP) through various stages of chemical treatment are identified from scanning electron microscopy (SEM), Fourier transform infra-red spectroscopy (FTIR), x-ray powder diffraction (XRD), and thermogravimetric analysis (TGA). Later, characterized nanocellulose is reinforced in a polyester matrix to fabricate nanocellulose-based composites according to the ASTM standard. The resulting nanocellulose composite performance is evaluated in the mechanical perspective through tensile and flexural loading. SEM, FTIR, and XRD showed that the process for extraction is efficient in obtaining 95% crystalline cellulose. Cellulose also showed good thermal stability with a peak thermal degradation temperature of 361 °C. Such cellulose when reinforced in a matrix material showed a noteworthy rise in tensile and flexural strengths of 43 MPa and 127 MPa, at a definite weight percent of 5%.

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

International Nuclear Information System (INIS)

Kurata, A.; Suzuki, S.; Iwamoto, K.; Miyazaki, T.; Inukai, M.; Abe, K.; Niki, J.; Yamada, M.; Fujii, K.; Kan, S.

2009-01-01

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.)

Saccharification of cellulose by acetolysis

Energy Technology Data Exchange (ETDEWEB)

Tanaka, T; Yamanaka, S; Takinami, K

1978-01-01

For saccharification of cellulose, an acetolysis method using assimilable acid with a microorganism was applied. Based on this method, a new method which gave totally assimilable products was established. The rigid crystalline structure of cellulose was disrupted by acetolysis with 2-2.5 times as much acetic anhydride as cellulose on a weight basis and 1 N sulfuric acid as a catalyst. Then for cleavage of O-acetyl ester and glycosidic bonds, the resulting amorphous acetolysate of cellulose could easily be hydrolyzed by heating in 1 N sulfuric acid at 120/sup 0/C for 1-1.5 h without over-disruption of glucose. Ninety-eight % of the cellulose used was recovered in the form of hydrolysate having about 30% saccharide concentration. The hydrolysate obtained was composed of 74% glucose, 13% cellobiose and 11% mono-O-acetyl glucose on a weight basis.

Ophthalmic manifestations of head injury.

Science.gov (United States)

Kowal, L

1992-02-01

Head injuries are frequently associated with ophthalmic problems. The commonest problems seen in this series of 161 patients with head injury were problems with poor accommodation (16% of patients; 58% of these persisted), convergence (14% of patients; 35% of these persisted), pseudomyopia (19%; 55% persisted) and optic atrophy (26% of the patients; 78% of these were mild and easily missed on routine testing, and 22% were severe). Motility disorders were common, especially cranial nerve palsies. Other less frequent motility disturbances included apparent inferior oblique palsy, comitant esotropia, and exotropia which was often of the convergence insufficiency type.

Outpatients flow management and ophthalmic electronic medical records system in university hospital using Yahgee Document View.

Science.gov (United States)

Matsuo, Toshihiko; Gochi, Akira; Hirakawa, Tsuyoshi; Ito, Tadashi; Kohno, Yoshihisa

2010-10-01

General electronic medical records systems remain insufficient for ophthalmology outpatient clinics from the viewpoint of dealing with many ophthalmic examinations and images in a large number of patients. Filing systems for documents and images by Yahgee Document View (Yahgee, Inc.) were introduced on the platform of general electronic medical records system (Fujitsu, Inc.). Outpatients flow management system and electronic medical records system for ophthalmology were constructed. All images from ophthalmic appliances were transported to Yahgee Image by the MaxFile gateway system (P4 Medic, Inc.). The flow of outpatients going through examinations such as visual acuity testing were monitored by the list "Ophthalmology Outpatients List" by Yahgee Workflow in addition to the list "Patients Reception List" by Fujitsu. Patients' identification number was scanned with bar code readers attached to ophthalmic appliances. Dual monitors were placed in doctors' rooms to show Fujitsu Medical Records on the left-hand monitor and ophthalmic charts of Yahgee Document on the right-hand monitor. The data of manually-inputted visual acuity, automatically-exported autorefractometry and non-contact tonometry on a new template, MaxFile ED, were again automatically transported to designated boxes on ophthalmic charts of Yahgee Document. Images such as fundus photographs, fluorescein angiograms, optical coherence tomographic and ultrasound scans were viewed by Yahgee Image, and were copy-and-pasted to assigned boxes on the ophthalmic charts. Ordering such as appointments, drug prescription, fees and diagnoses input, central laboratory tests, surgical theater and ward room reservations were placed by functions of the Fujitsu electronic medical records system. The combination of the Fujitsu electronic medical records and Yahgee Document View systems enabled the University Hospital to examine the same number of outpatients as prior to the implementation of the computerized filing system.

21 CFR 524.1484a - Neomycin sulfate ophthalmic ointment.

Science.gov (United States)

2010-04-01

... (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS OPHTHALMIC AND TOPICAL DOSAGE FORM NEW ANIMAL DRUGS...) Severe infections should be supplemented by systemic therapy. (5) Prolonged administration of the drug... bacteria or fungi appear during therapy, appropriate measures should be taken. (6) Federal law restricts...

Evaluation of microcrystalline cellulose modifed from alpha ...

African Journals Online (AJOL)

Alpha cellulose was obtained from Costus afer and part of it was modified to microcrystalline cellulose (CAMCC). The physicochemical properties of the microcrystalline cellulose were determined and compared with those of commercial microcrystalline cellulose (Avicel 101). The swelling capacity, hydration capacity, loss ...

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.

Salvage/Adjuvant Brachytherapy After Ophthalmic Artery Chemosurgery for Intraocular Retinoblastoma

International Nuclear Information System (INIS)

Francis, Jasmine H.; Barker, Christopher A.; Wolden, Suzanne L.; McCormick, Beryl; Segal, Kira; Cohen, Gil; Gobin, Y. Pierre; Marr, Brian P.; Brodie, Scott E.; Dunkel, Ira J.; Abramson, David H.

2013-01-01

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

Cellulose utilization: an overview

Energy Technology Data Exchange (ETDEWEB)

Bassham, J A

1975-01-01

To summarize, the conversion of cellulose to ethanol via hydrolysis to glucose followed by fermentation appears to be highly efficient in terms of energy conservation, yield, and quality of product, especially when reasonably high quality cellulosic waste is available.

Engineering control of bacterial cellulose production using a genetic toolkit and a new cellulose-producing strain

Science.gov (United States)

Florea, Michael; Hagemann, Henrik; Santosa, Gabriella; Micklem, Chris N.; Spencer-Milnes, Xenia; de Arroyo Garcia, Laura; Paschou, Despoina; Lazenbatt, Christopher; Kong, Deze; Chughtai, Haroon; Jensen, Kirsten; Freemont, Paul S.; Kitney, Richard; Reeve, Benjamin; Ellis, Tom

2016-01-01

Bacterial cellulose is a strong and ultrapure form of cellulose produced naturally by several species of the Acetobacteraceae. Its high strength, purity, and biocompatibility make it of great interest to materials science; however, precise control of its biosynthesis has remained a challenge for biotechnology. Here we isolate a strain of Komagataeibacter rhaeticus (K. rhaeticus iGEM) that can produce cellulose at high yields, grow in low-nitrogen conditions, and is highly resistant to toxic chemicals. We achieved external control over its bacterial cellulose production through development of a modular genetic toolkit that enables rational reprogramming of the cell. To further its use as an organism for biotechnology, we sequenced its genome and demonstrate genetic circuits that enable functionalization and patterning of heterologous gene expression within the cellulose matrix. This work lays the foundations for using genetic engineering to produce cellulose-based materials, with numerous applications in basic science, materials engineering, and biotechnology. PMID:27247386

Opportunity for profitable investments in cellulosic biofuels

International Nuclear Information System (INIS)

Babcock, Bruce A.; Marette, Stephan; Treguer, David

2011-01-01

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. (author)

Management of ocular inflammation and pain following cataract surgery: focus on bromfenac ophthalmic solution

OpenAIRE

Cho, Hyung; Wolf, Kenneth J; Wolf, Eric J

2009-01-01

Hyung Cho1, Kenneth J Wolf1, Eric J Wolf21Department of Ophthalmology, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, New York, USA; 2Department of Ophthalmology, Edward S. Harkness Eye Institute of Columbia University College of Physicians and Surgeons, New York, NY, USAAbstract: Recently, several new ophthalmic NSAID products have been introduced for commercial use in the United States. The purpose of this review is to briefly overview the ophthalmic NSAIDs currently...

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.)

The Synthesis of a Novel Cellulose Physical Gel

Directory of Open Access Journals (Sweden)

Jiufang Duan

2014-01-01

Full Text Available Cellulose possessing β-cyclodextrin (β-CD was used as a host molecule and cellulose possessing ferrocene (Fc as a guest polymer. Infrared spectra, differential scanning calorimetry (DSC, ultraviolet spectroscopy (UV, and contact angle analysis were used to characterise the material structure and the inclusion behaviour. The results showed that the β-CD-cellulose and the Fc-cellulose can form inclusion complexes. Moreover, ferrocene oxidation, and reduction of state can be adjusted by sodium hypochlorite (NaClO as an oxidant and glutathione (GSH as a reductant. In this study, a physical gel based on β-CD-cellulose/Fc-cellulose was formed under mild conditions in which autonomous healing between cut surfaces occurred after 24 hours. The physical gel can be controlled in the sol-gel transition. The compressive strength of the Fc-cellulose/β-CD-cellulose gel increased with increased cellulose concentration. The host-guest interaction between the side chains of cellulose could strengthen the gel. The cellulose physical gel may eventually be used as a stimulus-responsive, healing material in biomedical applications.

Cellulose microfibril structure: inspirations from plant diversity

Science.gov (United States)

Roberts, A. W.

2018-03-01

Cellulose microfibrils are synthesized at the plasma membrane by cellulose synthase catalytic subunits that associate to form cellulose synthesis complexes. Variation in the organization of these complexes underlies the variation in cellulose microfibril structure among diverse organisms. However, little is known about how the catalytic subunits interact to form complexes with different morphologies. We are using an evolutionary approach to investigate the roles of different catalytic subunit isoforms in organisms that have rosette-type cellulose synthesis complexes.

Longitudinal ophthalmic findings in a child with Helsmoortel-Van der Aa Syndrome

Directory of Open Access Journals (Sweden)

Michael J. Gale

2018-06-01

Full Text Available Purpose: We present the first detailed ophthalmic description of a child with Helsmoortel-Van der Aa Syndrome (HVDAS, including longitudinal follow-up and analysis. Observations: After extensive workup, a young child with poor visual behavior, hypotonic cerebral palsy, intellectual disability, and global developmental delay was found to have a heterozygous de novo mutation in the ADNP gene and diagnosed with HVDAS. Ophthalmic findings were remarkable for progressive nystagmus, macular pigment mottling, mild foveal hypoplasia with abnormal macular laminations, persistent rod dysfunction with electronegative waveform, and progressive cone degeneration. Conclusions and importance: Patients with HVDAS are known to have abnormal visual behavior due to refractive or cortical impairment. However, we present the first description, to our knowledge, of an association with retinal mal-development and degeneration. Thus, patients with HVDAS should be referred for ophthalmic genetics evaluation, and HVDAS should be on the differential diagnosis for young children with global developmental delay who present with nystagmus, rod and cone dysfunction with electronegative waveform, and relative lack of severe structural degeneration on optical coherence tomography. Keywords: Helsmoortel-Van der Aa Syndrome, HVDAS, Activity-dependent neuroprotective protein, ADNP, Nystagmus, Retinal degeneration, Electronegative waveform, Optical coherence tomography

Diagnosis, treatment, and outcome of and risk factors for ophthalmic disease in leopard geckos (Eublepharis macularius) at a veterinary teaching hospital: 52 cases (1985-2013).

Science.gov (United States)

Wiggans, K Tomo; Sanchez-Migallon Guzman, David; Reilly, Christopher M; Vergneau-Grosset, Claire; Kass, Philip H; Hollingsworth, Steven R

2018-02-01

OBJECTIVE To describe diagnosis, treatment, and outcome of and risk factors for ophthalmic disease in leopard geckos (Eublepharis macularius) evaluated at a veterinary teaching hospital. DESIGN Retrospective case series. ANIMALS 112 of 144 (78%) leopard geckos that were evaluated at a veterinary teaching hospital in January 1985 through October 2013 and for which sufficient medical record information was available. PROCEDURES Information from medical records was used to identify leopard geckos with ophthalmic disease, characterize cases, and determine risk factors for the presence of ophthalmic disease. RESULTS Of the 112 leopard geckos, 52 (46%) had ophthalmic disease (mainly corneal or conjunctival disease). Female geckos were less likely to have ophthalmic disease, and there was a positive association between increasing age and ophthalmic disease. Use of a paper towel substrate, absence of any heat source, and lack of vitamin A supplementation were positively associated with a diagnosis of ophthalmic disease. Head dysecdysis was the only concurrent disorder significantly associated with ophthalmic disease. At necropsy, 5 affected leopard geckos had squamous metaplasia of the conjunctivae. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that ophthalmic disease is a common finding in leopard geckos. The cause of ocular surface disease in leopard geckos may be multifactorial, and hypovitaminosis A may be an important risk factor. Although animals receiving supplemental vitamin A were less likely to have ophthalmic disease, further understanding is required regarding the metabolism of and nutritional requirements for vitamin A in leopard geckos.

The international forum of ophthalmic simulation: developing a virtual reality training curriculum for ophthalmology.

Science.gov (United States)

Saleh, George M; Lamparter, Julia; Sullivan, Paul M; O'Sullivan, Fiona; Hussain, Badrul; Athanasiadis, Ioannis; Litwin, Andre S; Gillan, Stewart N

2013-06-01

To investigate the effect of a structured, supervised, cataract simulation programme on ophthalmic surgeons in their first year of training, and to evaluate the level of skill transfer. Trainees with minimal intraocular and simulator experience in their first year of ophthalmology undertook a structured, sequential, customised, virtual reality (VR) cataract training programme developed through the International Forum of Ophthalmic Simulation. A set of one-handed, bimanual, static and dynamic tasks were evaluated before and after the course and scores obtained. Statistical significance was evaluated with the Wilcoxon sign-rank test. The median precourse score of 101.50/400 (IQR 58.75-145.75) was significantly improved after completing the training programme ((postcourse score: 302/400, range: 266.25-343), p<0.001). While improvement was evident and found to be statistically significant in all parameters, greatest improvements were found for capsulorhexis and antitremor training ((Capsulorhexis: precourse score=0/100, range 0-4.5; postcourse score=81/100, range 13-87.75; p=0.002), (antitremor training: precourse score=0/100, range 0-0; postcourse score=80/100, range 60.25-91.50; p=0.001)). Structured and supervised VR training can offer a significant level of skills transfer to novice ophthalmic surgeons. VR training at the earliest stage of ophthalmic surgical training may, therefore, be of benefit.

Irradiation effects in wood and cellulose

International Nuclear Information System (INIS)

McLaren, K.G.

1976-01-01

For cellulosic materials the predominant effect of high energy radiation is depolymerisation and degradation by chain scission, although there is some evidence that crosslinking or cellulose stabilisation can occur under certain conditions. When the cellulose is in the form of a natural product such as wood, where it is intimately associated with other polysaccharides, lignins, resins and gums, the effects of radiation can be significantly modified. Examination of cellulose produced by chemical pulping treatment of wood which had been previously given small doses of radiation, showed significant differences in the extent of cellulose depolymerisation with different wood species. The relevance of this work to the paper pulp industry will also be discussed. (author)

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

RADIOCHEMICAL YIELDS OF GRAFT POLYMERIZATION REACTIONS OF CELLULOSE

Energy Technology Data Exchange (ETDEWEB)

Arthur, Jr, J C; Blouin, F A

1963-12-15

The preparation of radioinduced graft polymers of cotton cellulose, while retaining the fibrous nature and high molecular weight of the cellulose, depended primarily on the radiochemical yields of cellulose reactions and of graft polymerization reactions. Yields of the initial major molecular changes in cellulosic polymer indicated that, in the case of scission of the molecule and carboxyl group formation, chain reactions were not initiated by radiation; however, in the case of carbonyl group formation chain reactions were initiated but quickly terminated. Generally, experimental procedures, used in graft polymerization reactions, were: simultaneous irradiation reactions, that is, application of monomers or solutions of monomers to cellulose or chemically modified celluloses, then irradiation; and post-irradiation reactions, that is, irradiation of cellulose or chemically modified celluloses, then after removal from the field of radiation, contacting the irradiated cellulose with monomer. Some of the most important factors influencing the radiochemical yields of graft polymerization reactions, of styrene and acrylonitrile onto cellulose were: concentration of monomer in treating solution; solvent; ratio of monomer solution to cellulose; prior chemical modification of cellulose; and absence of oxygen, particularly in post-irradiation reactions. Experimental data are presented, and the direct and indirect effects of Co/sup 60/ gamma radiation on these reactions are discussed. (auth)

Pretreatment assisted synthesis and characterization of cellulose nanocrystals and cellulose nanofibers from absorbent cotton.

Science.gov (United States)

Abu-Danso, Emmanuel; Srivastava, Varsha; Sillanpää, Mika; Bhatnagar, Amit

2017-09-01

In this work, cellulose nanocrystals (CNCs) and cellulose nanofibers (CNFs) were synthesized from absorbent cotton. Two pretreatments viz. dewaxing and bleaching with mild alkali were applied to the precursor (cotton). Acid hydrolysis was conducted with H 2 SO 4 and dissolution of cotton was achieved with a mixture of NaOH-thiourea-urea-H 2 O at -3°C. Synthesized cellulose samples were characterized using FTIR, XRD, SEM, BET, and zeta potential. It seems that synthesis conditions contributed to negative surface charge on cellulose samples and CNCs had the higher negative surface charge compared to CNFs. Furthermore, BET surface area, pore volume and pore diameter of CNCs were found to be higher as compared to CNFs. The dewaxed cellulose nanofibers (CNF D) had a slightly higher BET surface area (0.47m 2 /g) and bigger pore diameter (59.87Å) from attenuated contraction compared to waxed cellulose nanofibers (CNFW) (0.38m 2 /g and 44.89Å). The XRD of CNCs revealed a semi-crystalline structure and the dissolution agents influenced the crystallinity of CNFs. SEM images showed the porous nature of CNFs, the flaky nature and the nano-sized width of CNCs. Synthesized CNF D showed a better potential as an adsorbent with an average lead removal efficiency of 91.49% from aqueous solution. Copyright © 2017 Elsevier B.V. All rights reserved.

Fluorescent cellulose nanocrystals via supramolecular assembly of terpyridine-modified cellulose nanocrystals and terpyridine-modified perylene

International Nuclear Information System (INIS)

Hassan, Mohammad L.; Moorefield, Charles M.; Elbatal, Hany S.; Newkome, George R.; Modarelli, David A.; Romano, Natalie C.

2012-01-01

Highlights: ► Surfaces of cellulose nanocrystals were modified with terpyridine ligands. ► Fluorescent nanocrystals could be obtained via self-assembly of terpyridine-modified perylene dye onto the terpyridine-modified cellulose nanocrystals. ► Further self-assembly of azide-functionalized terpyridine onto the fluorescent cellulose nanocrystals was possible to obtain nanocellulosic material with expected use in bioimaging. - Abstract: Due to their natural origin, biocompatibility, and non-toxicity, cellulose nanocrystals are promising candidates for applications in nanomedicine. Highly fluorescent nanocellulosic material was prepared via surface modification of cellulose nanocrystals with 2,2′:6′,2″-terpyridine side chains followed by supramolecular assembly of terpyridine-modified perylene dye onto the terpyridine-modified cellulose nanocrystals (CTP) via Ru III /Ru II reduction. The prepared terpyridine-modified cellulose-Ru II -terpyridine-modified perylene (CTP-Ru II -PeryTP) fluorescent nanocrystals were characterized using cross-polarized/magic angle spin 13 C nuclear magnetic resonance (CP/MAS 13 C NMR), Fourier transform infrared (FTIR), UV–visible, and fluorescence spectroscopy. In addition, further self-assembly of terpyridine units with azide functional groups onto CTP-Ru II -PeryTP was possible via repeating the Ru III /Ru II reduction protocol to prepare supramolecular fluorescent nanocrystals with azide functionality (CTP-Ru II -PeryTP-Ru II -AZTP). The prepared derivative may have potential application in bio-imaging since the terminal azide groups can be easily reacted with antigens via “Click” chemistry reaction.

Current characterization methods for cellulose nanomaterials.

Science.gov (United States)

Foster, E Johan; Moon, Robert J; Agarwal, Umesh P; Bortner, Michael J; Bras, Julien; Camarero-Espinosa, Sandra; Chan, Kathleen J; Clift, Martin J D; Cranston, Emily D; Eichhorn, Stephen J; Fox, Douglas M; Hamad, Wadood Y; Heux, Laurent; Jean, Bruno; Korey, Matthew; Nieh, World; Ong, Kimberly J; Reid, Michael S; Renneckar, Scott; Roberts, Rose; Shatkin, Jo Anne; Simonsen, John; Stinson-Bagby, Kelly; Wanasekara, Nandula; Youngblood, Jeff

2018-04-23

A new family of materials comprised of cellulose, cellulose nanomaterials (CNMs), having properties and functionalities distinct from molecular cellulose and wood pulp, is being developed for applications that were once thought impossible for cellulosic materials. Commercialization, paralleled by research in this field, is fueled by the unique combination of characteristics, such as high on-axis stiffness, sustainability, scalability, and mechanical reinforcement of a wide variety of materials, leading to their utility across a broad spectrum of high-performance material applications. However, with this exponential growth in interest/activity, the development of measurement protocols necessary for consistent, reliable and accurate materials characterization has been outpaced. These protocols, developed in the broader research community, are critical for the advancement in understanding, process optimization, and utilization of CNMs in materials development. This review establishes detailed best practices, methods and techniques for characterizing CNM particle morphology, surface chemistry, surface charge, purity, crystallinity, rheological properties, mechanical properties, and toxicity for two distinct forms of CNMs: cellulose nanocrystals and cellulose nanofibrils.

Laser cleaning of particulates from paper: Comparison between sized ground wood cellulose and pure cellulose

International Nuclear Information System (INIS)

Arif, S.; Kautek, W.

2013-01-01

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.

Microsurgical treatment of carotid-ophthalmic aneurysm associated with multiple anterior and posterior circulation aneurysms

Science.gov (United States)

Wang, Jiantao; Kan, Zhisheng; Wang, Shuo

2017-01-01

Abstract Background: The clipping of multiple intracranial aneurysms in 1 stage is uncommon. In this case, we report clipping of an ophthalmic aneurysm associated with multiple anterior and posterior circulation aneurysms via the Dolenc approach. Methods: The main symptoms of the patient are headache, along with nausea and vomiting. The patient's arteriogram revealed a wide-necked aneurysm of the right ophthalmic artery, an irregular aneurysm of the anterior communicating artery, and a basilar artery aneurysm. The surgical intervention for these aneurysms is a challenge because of the complex anatomical relationship with the surrounding structures. The 3 aneurysms, which were not amenable to a single intervention, were successfully clipped in 1 incision. Results: After surgery, the patient reported feeling well. One year after surgery, the patient had no SAH recurrence. Conclusions: Occasionally, surgical treatment was used even for aneurysms of the carotid-ophthalmic artery with aneurysms of anterior communicating artery and basilar artery, which are contraindicated for interventional therapy. PMID:28422878

The productive cellulase binding capacity of cellulosic substrates.

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Karuna, Nardrapee; Jeoh, Tina

2017-03-01

Cellulosic biomass is the most promising feedstock for renewable biofuel production; however, the mechanisms of the heterogeneous cellulose saccharification reaction are still unsolved. As cellulases need to bind isolated molecules of cellulose at the surface of insoluble cellulose fibrils or larger aggregated cellulose structures in order to hydrolyze glycosidic bonds, the "accessibility of cellulose to cellulases" is considered to be a reaction limiting property of cellulose. We have defined the accessibility of cellulose to cellulases as the productive binding capacity of cellulose, that is, the concentration of productive binding sites on cellulose that are accessible for binding and hydrolysis by cellulases. Productive cellulase binding to cellulose results in hydrolysis and can be quantified by measuring hydrolysis rates. In this study, we measured the productive Trichoderma reesei Cel7A (TrCel7A) binding capacity of five cellulosic substrates from different sources and processing histories. Swollen filter paper and bacterial cellulose had higher productive binding capacities of ∼6 µmol/g while filter paper, microcrystalline cellulose, and algal cellulose had lower productive binding capacities of ∼3 µmol/g. Swelling and regenerating filter paper using phosphoric acid increased the initial accessibility of the reducing ends to TrCel7A from 4 to 6 µmol/g. Moreover, this increase in initial productive binding capacity accounted in large part for the difference in the overall digestibility between filter paper and swollen filter paper. We further demonstrated that an understanding of how the productive binding capacity declines over the course of the hydrolysis reaction has the potential to predict overall saccharification time courses. Biotechnol. Bioeng. 2017;114: 533-542. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Ductile all-cellulose nanocomposite films fabricated from core-shell structured cellulose nanofibrils.

Science.gov (United States)

Larsson, Per A; Berglund, Lars A; Wågberg, Lars

2014-06-09

Cellulosic materials have many desirable properties such as high mechanical strength and low oxygen permeability and will be an important component in a sustainable biomaterial-based society, but unfortunately they often lack the ductility and formability offered by petroleum-based materials. This paper describes the fabrication and characterization of nanocomposite films made of core-shell modified cellulose nanofibrils (CNFs) surrounded by a shell of ductile dialcohol cellulose, created by heterogeneous periodate oxidation followed by borohydride reduction of the native cellulose in the external parts of the individual fibrils. The oxidation with periodate selectively produces dialdehyde cellulose, and the process does not increase the charge density of the material. Yet the modified cellulose fibers could easily be homogenized to CNFs. Prior to film fabrication, the CNF was shown by atomic force microscopy to be 0.5-2 μm long and 4-10 nm wide. The films were fabricated by filtration, and besides uniaxial tensile testing at different relative humidities, they were characterized by scanning electron microscopy and oxygen permeability. The strength-at-break at 23 °C and 50% RH was 175 MPa, and the films could, before rupture, be strained, mainly by plastic deformation, to about 15% and 37% at 50% RH and 90% RH, respectively. This moisture plasticization was further utilized to form a demonstrator consisting of a double-curved structure with a nominal strain of 24% over the curvature. At a relative humidity of 80%, the films still acted as a good oxygen barrier, having an oxygen permeability of 5.5 mL·μL/(m(2)·24 h·kPa). These properties indicate that this new material has a potential for use as a barrier in complex-shaped structures and hence ultimately reduce the need for petroleum-based plastics.

21 CFR 172.870 - Hydroxypropyl cellulose.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Hydroxypropyl cellulose. 172.870 Section 172.870... CONSUMPTION Multipurpose Additives § 172.870 Hydroxypropyl cellulose. The food additive hydroxypropyl cellulose may be safely used in food, except standardized foods that do not provide for such use, in...

The mechanism of Acetobacter xylinum cellulose biosynthesis: direction of chain elongation and the role of lipid pyrophosphate intermediates in the cell membrane

International Nuclear Information System (INIS)

Han, N.S.; Robyt, J.F.

1998-01-01

The biosynthesis of Acetobacter xylinum ATCC 10821 cellulose has been studied with resting cells and a membrane preparation using 14 C-pulse and chase reactions, with d-glucose and UDPGlc, respectively. Cellulose was biosynthesized from UDPGlc, and it was found to be tightly associated with both the cells and the membrane. The cellulose chains could be released from the cells and the membrane preparation by treating at pH 2, 100 C for 20 min. The cellulose chains that were released from the pulse and pulse-chase reactions were purified and separated from any low molecular weight substances by gel chromatography on Bio-Gel P4. They were then reduced with sodium borohydride and hydrolyzed with 4 M trifluoroacetic acid at 121 C for 2 h. Labeled products from the acid hydrolyzates were separated by paper chromatography and found to be d-glucose and d-glucitol. The amount of radioactivity in the products was determined by liquid scintillation counting. It was found that the pulsed products from the resting cells gave a ratio of d-[ 14 C]glucitol to d-[ 14 C]glucose of 1:11, and after chasing, the ratio decreased to 1:36. The pulsed products from the membrane gave a ratio of d-[ 14 C]glucitol to d-[ 14 C]glucose of 1:12, and after chasing for 5 min the ratio decreased to 1:43, and after 10 min, the ratio decreased to 1:66. These results show that the labeled d-glucitol obtained from the reducing end of the cellulose chain is chased into the interior of the cellulose chain during synthesis, showing that the cellulose chain is elongated from the reducing end. An insertion mechanism for the synthesis of cellulose from UDPGlc is proposed that involves lipid pyrophosphate glycosyl intermediates and three membrane enzymes: lipid phosphate:UDPGlc phosphotransferase, cellulose synthase, and lipid pyrophosphate phosphohydrolase. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

Cellulose Nanocrystals vs. Cellulose Nanofibrils: A Comparative study on Their Microstructures and Effects as Polymer Reinforcing Agents

Science.gov (United States)

Xuezhu Xu; Fei Liu; Long Jiang; J.Y. Zhu; Darrin Haagenson; Dennis P. Wiesenborn

2013-01-01

Both cellulose nanocrystals (CNCs) and cellulose nanofibrils (CNFs) are nanoscale cellulose fibers that have shown reinforcing effects in polymer nanocomposites. CNCs and CNFs are different in shape, size and composition. This study systematically compared their morphologies, crystalline structure, dispersion properties in polyethylene oxide (PEO) matrix, interactions...

[Optimization of benzalkonium chloride concentration in 0.0015% tafluprost ophthalmic solution from the points of ocular surface safety and preservative efficacy].

Science.gov (United States)

Asada, Hiroyuki; Takaoka-Shichijo, Yuko; Nakamura, Masatsugu; Kimura, Akio

2010-06-01

Optimization of benzalkonium chloride (alkyl dimethylbenzylammonium chloride: BAK) concentration as preservative in 0.0015% tafluprost ophthalmic solution (Tapros 0.0015% ophthalmic solution), an anti-glaucoma medicine, was examined from the points of ocular surface safety and preservative efficacy. BAKC(12), which is dodecyl dimethylbenzylammonium chloride, and BAKmix, which is the mixture of dodecyl, tetradecyl and hexadecyl dimethylbenzylammonium chloride were used in this study. The effects of BAKC(12) concentrations and the BAK types, BAKC(12) and BAKmix, in tafluprost ophthalmic solution on ocular surface safety were evaluated using the in vitro SV 40-immobilized human corneal epithelium cell line (HCE-T). Following treatments of Tafluprost ophthalmic solutions with BAKC(12), its concentration dependency was observed on cell viability of HCE-T. The cell viability of HCE-T after treatment of these solutions with 0.001% to 0.003% BAKC(12) for 5 minutes were the same level as that after treatment of the solution without BAK. Tafluprost ophthalmic solution with 0.01% BAKC(12) was safer for the ocular surface than the same solution with 0.01% BAKmix. Preservatives-effectiveness tests of tafluprost ophthalmic solutions with various concentrations of BAKC(12) were performed according to the Japanese Pharmacopoeia (JP), and solutions with more than 0.0005% BAKC(12) conformed to JP criteria. It was concluded that 0.0005% to 0.003% of BAKC(12) in tafluprost ophthalmic solution was optimal, namely, well-balanced from the points of ocular surface safety and preservative efficacy.

Cellulose Anionic Hydrogels Based on Cellulose Nanofibers As Natural Stimulants for Seed Germination and Seedling Growth.

Science.gov (United States)

Zhang, Hao; Yang, Minmin; Luan, Qian; Tang, Hu; Huang, Fenghong; Xiang, Xia; Yang, Chen; Bao, Yuping

2017-05-17

Cellulose anionic hydrogels were successfully prepared by dissolving TEMPO-oxidized cellulose nanofibers in NaOH/urea aqueous solution and being cross-linked with epichlorohydrin. The hydrogels exhibited microporous structure and high hydrophilicity, which contribute to the excellent water absorption property. The growth indexes, including the germination rate, root length, shoot length, fresh weight, and dry weight of the seedlings, were investigated. The results showed that cellulose anionic hydrogels with suitable carboxylate contents as plant growth regulators could be beneficial for seed germination and growth. Moreover, they presented preferable antifungal activity during the breeding and growth of the sesame seed breeding. Thus, the cellulose anionic hydrogels with suitable carboxylate contents could be applied as soilless culture mediums for plant growth. This research provided a simple and effective method for the fabrication of cellulose anionic hydrogel and evaluated its application in agriculture.

21 CFR 524.390d - Chloramphenicol-prednisolone ophthalmic ointment.

Science.gov (United States)

2010-04-01

.... 017030 in § 510.600(c) of this chapter. (c) Conditions of use. Dogs and cats—(1) Amount. Apply 4 to 6...) Limitations. Therapy for cats should not exceed 7 days, prolonged use in cats may produce blood dyscrasia. As... institute appropriate therapy. All topical ophthalmic preparations containing corticosteroids, with or...

Graft Copolymerization Of Methyl Methacrylate Onto Agave Cellulose

International Nuclear Information System (INIS)

Noor Afizah Rosli; Ishak Ahmad; Ibrahim Abdullah; Farah Hannan Anuar

2014-01-01

The grafting polymerization of methyl methacrylate (MMA) and Agave cellulose was prepared and the grafting reaction conditions were optimized by varying the reaction time and temperature, and ratio of monomer to cellulose. The resulting graft copolymers were characterized by Fourier transform infrared, X-ray diffraction analysis, thermogravimetric analysis, and scanning electron microscopy (SEM). The experimental results showed that the optimal conditions were at a temperature of 45 degree Celsius for 90 min with ratio monomer to cellulose at 1:1 (g/ g). An additional peak at 1738 cm -1 which was attributed to the C=O of ester stretching vibration of poly(methyl methacrylate), appeared in the spectrum of grafted Agave cellulose. A slight decrease of crystallinity index upon grafting was found from 0.74 to 0.68 for cellulose and grafted cellulose, respectively. Grafting of MMA onto cellulose enhanced its thermal stability and SEM observation further furnished evidence of grafting MMA onto Agave cellulose with increasing cellulose diameter and surface roughness. (author)

The Use of Flow Diverting Stents to Treat Para-Ophthalmic Aneurysms

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Pervinder Bhogal

2017-08-01

Full Text Available Background and purposeFew publications have dealt exclusively with the use of flow diverter stents for the treatment of para-ophthalmic aneurysms. We sought to determine the efficacy of flow diverting stents (FDSs to treat aneurysms in this specific location.MethodsWe retrospectively reviewed our database of prospectively collected information for all patients treated with flow diversion for an unruptured saccular para-ophthalmic aneurysm between September 2009 and January 2016. The aneurysm fundus size, neck size, number and type of FDS, complications, and follow-up data were recorded.ResultsWe identified 74 patients that matched our inclusion criteria. Of these patients, 18 patients were male (24.3%. The average fundus size was 4.8 mm, 11 aneurysms had previous coil occlusions and 63 were treated solely with flow diversion. At an initial angiographic follow-up (mean avg. 3.2 months, 71.8% of the aneurysms were occluded, and at the last follow-up (mean avg. 31.8 months, 88.9% of aneurysms were occluded. One patient suffered permanent morbidity (1.36% secondary to interruption of the antiplatelet medication and another died (1.36% secondary to in-stent thrombosis that was also due to an interruption in the antiplatelet medication.ConclusionTreatment of saccular para-ophthalmic aneurysms with FDS is feasible and carries a high degree of technical success with low complication rates and excellent rates of aneurysm exclusion.

Gatifloxacin Ophthalmic Solution for Treatment of Bacterial Conjunctivitis: Safety, Efficacy and Patient Perspective

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Clyde Schultz

2012-01-01

Full Text Available Gatifloxacin is a fourth generation fluroquinolone antibiotic that has been prescribed for systemic use. However, the drug which was developed by Kyorin (Japan was linked to toxic reactions and death and was banned in the United States and Canada for use as an oral dosage form. It continues to be used as a topical application for ophthalmic conditions as the systemic toxicity seen when taking the drug orally has not been observed with ophthalmic use. The available data indicate that ocular use of gatifloxacin is safe, and effective against a broad spectrum of bacteria, including intracellular bacteria and anaerobes.

Cellulose: To depolymerize… or not to?

Science.gov (United States)

Coseri, Sergiu

Oxidation of the primary OH groups in cellulose is a pivotal reaction both at lab and industrial scale, leading to the value-added products, i.e. oxidized cellulose which have tremendous applications in medicine, pharmacy and hi-tech industry. Moreover, the introduction of carboxyl moieties creates prerequisites for further cellulose functionalization through covalent attachment or electrostatic interactions, being an essential achievement designed to boost the area of cellulose-based nanomaterials fabrication. Various methods for the cellulose oxidation have been developed in the course of time, aiming the selective conversion of the OH groups. These methods use: nitrogen dioxide in chloroform, alkali metal nitrites and nitrates, strong acids alone or in combination with permanganates or sodium nitrite, ozone, and sodium periodate or lead (IV) tetraacetate. In the case of the last two reagents, cellulose dialdehydes derivatives are formed, which are further oxidized by sodium chlorite or hydrogen peroxide to form dicarboxyl groups. A major improvement in the cellulose oxidation was represented by the introduction of the stable nitroxyl radicals, such as 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO). However, a major impediment for the researchers working in this area is related with the severe depolymerisation occurred during the TEMPO-mediated conversion of CH 2 OH into COOH groups. On the other hand, the cellulose depolymerisation represent the key step, in the general effort of searching for alternative strategies to develop new renewable, carbon-neutral energy sources. In this connection, exploiting the biomass feed stocks to produce biofuel and other low molecular organic compounds, involves a high amount of research to improve the overall reaction conditions, limit the energy consumption, and to use benign reagents. This work is therefore focused on the parallelism between these two apparently antagonist processes involving cellulose, building a necessary

Cellulose-Based Bio- and Nanocomposites: A Review

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Susheel Kalia

2011-01-01

Full Text Available Cellulose macro- and nanofibers have gained increasing attention due to the high strength and stiffness, biodegradability and renewability, and their production and application in development of composites. Application of cellulose nanofibers for the development of composites is a relatively new research area. Cellulose macro- and nanofibers can be used as reinforcement in composite materials because of enhanced mechanical, thermal, and biodegradation properties of composites. Cellulose fibers are hydrophilic in nature, so it becomes necessary to increase their surface roughness for the development of composites with enhanced properties. In the present paper, we have reviewed the surface modification of cellulose fibers by various methods. Processing methods, properties, and various applications of nanocellulose and cellulosic composites are also discussed in this paper.

Cellulose-Based Nanomaterials for Energy Applications.

Science.gov (United States)

Wang, Xudong; Yao, Chunhua; Wang, Fei; Li, Zhaodong

2017-11-01

Cellulose is the most abundant natural polymer on earth, providing a sustainable green resource that is renewable, degradable, biocompatible, and cost effective. Recently, nanocellulose-based mesoporous structures, flexible thin films, fibers, and networks are increasingly developed and used in photovoltaic devices, energy storage systems, mechanical energy harvesters, and catalysts components, showing tremendous materials science value and application potential in many energy-related fields. In this Review, the most recent advancements of processing, integration, and application of cellulose nanomaterials in the areas of solar energy harvesting, energy storage, and mechanical energy harvesting are reviewed. For solar energy harvesting, promising applications of cellulose-based nanostructures for both solar cells and photoelectrochemical electrodes development are reviewed, and their morphology-related merits are discussed. For energy storage, the discussion is primarily focused on the applications of cellulose-based nanomaterials in lithium-ion batteries, including electrodes (e.g., active materials, binders, and structural support), electrolytes, and separators. Applications of cellulose nanomaterials in supercapacitors are also reviewed briefly. For mechanical energy harvesting, the most recent technology evolution in cellulose-based triboelectric nanogenerators is reviewed, from fundamental property tuning to practical implementations. At last, the future research potential and opportunities of cellulose nanomaterials as a new energy material are discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Acetone-based cellulose solvent.

Science.gov (United States)

Kostag, Marc; Liebert, Tim; Heinze, Thomas

2014-08-01

Acetone containing tetraalkylammonium chloride is found to be an efficient solvent for cellulose. The addition of an amount of 10 mol% (based on acetone) of well-soluble salt triethyloctylammonium chloride (Et3 OctN Cl) adjusts the solvent's properties (increases the polarity) to promote cellulose dissolution. Cellulose solutions in acetone/Et3 OctN Cl have the lowest viscosity reported for comparable aprotic solutions making it a promising system for shaping processes and homogeneous chemical modification of the biopolymer. Recovery of the polymer and recycling of the solvent components can be easily achieved. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Regioselective Synthesis of Cellulose Ester Homopolymers

Science.gov (United States)

Daiqiang Xu; Kristen Voiges; Thomas Elder; Petra Mischnick; Kevin J. Edgar

2012-01-01

Regioselective synthesis of cellulose esters is extremely difficult due to the small reactivity differences between cellulose hydroxyl groups, small differences in steric demand between acyl moieties of interest, and the difficulty of attaching and detaching many protecting groups in the presence of cellulose ester moieties without removing the ester groups. Yet the...

Ophthalmic epidemiology in Europe

DEFF Research Database (Denmark)

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

2016-01-01

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...

Cytocompatible cellulose hydrogels containing trace lignin

International Nuclear Information System (INIS)

Nakasone, Kazuki; Kobayashi, Takaomi

2016-01-01

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 12 h. 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 0.43 N/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. - Highlights: • Cellulose hydrogel films with trace lignin were obtained from sugarcane bagasse. • Lignin content was found to be in the range of 1.62 − 0.68% by UV–Vis spectroscopy. • Higher lignin content strengthened mechanical properties of the hydrogel films. • Trace lignin affected the hydrogel morphology such as roughness and porosity. • High cell proliferation was observed in the hydrogel containing 1.68% lignin.

Cytocompatible cellulose hydrogels containing trace lignin

Energy Technology Data Exchange (ETDEWEB)

Nakasone, Kazuki; Kobayashi, Takaomi, E-mail: takaomi@nagaoakut.ac.jp

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 12 h. 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 0.43 N/mm{sup 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. - Highlights: • Cellulose hydrogel films with trace lignin were obtained from sugarcane bagasse. • Lignin content was found to be in the range of 1.62 − 0.68% by UV–Vis spectroscopy. • Higher lignin content strengthened mechanical properties of the hydrogel films. • Trace lignin affected the hydrogel morphology such as roughness and porosity. • High cell proliferation was observed in the hydrogel containing 1.68% lignin.

Comparison the physicochemical properties of bunch press fibre cellulose and cyclone fibre cellulose of waste from industry Crude Palm Oil (CPO

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Irfan Gustian

2013-10-01

Full Text Available Normal 0 false false false EN-US X-NONE X-NONE Study on comparison the physicochemical properties of bunch press fibre cellulose (Bpfc and cyclone fibre cellulose (Cfc wastes from industry Crude Palm oil (CPO have been performed. The physicochemical properties both of celluloses have been done such as the average degree of polymerization (DP, solubility properties, functional group analysis, thermal properties and X-ray diffraction patterns. The average degrees of polymerization (DP have been obtained 2195 and 567 for Bpfc and Cfc. Bunch press fibre cellulose and cyclone fibre cellulose were soluble in cupriethylenediamine (CED. FT-IR analysis showed the same pattern of spectrum but different intensities. Thermal stability of bunch press fibre cellulose and cyclone fibre cellulose remains stable up to a temperature of 250 °C. Glass transition bunch press fibre cellulose greater than the glass transition cyclone fibre cellulose and X-ray diffraction pattern shows the same pattern and intensity varies.

Chapter 2.1 Integrated Production of Cellulose Nanofibrils and Cellulosic Biofuel by Enzymatic Hydrolysis of wood Fibers

Science.gov (United States)

Ronald Sabo; J.Y. Zhu

2013-01-01

One key barrier to converting woody biomass to biofuel through the sugar platform is the low efficiency of enzymatic cellulose saccharification due to the strong recalcitrance of the crystalline cellulose. Significant past research efforts in cellulosic biofuels have focused on overcoming the recalcitrance of lignocelluloses to enhance the saccharification of...

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

Long-term ophthalmic health care in Usher syndrome type I from an ICF perspective.

Science.gov (United States)

Möller, Kerstin; Eriksson, Kristina; Sadeghi, André M; Möller, Claes; Danermark, Berth

2009-01-01

The aim was to explore ophthalmic health care in female patients with Usher Syndrome type I (USH I) over 20 years and to evaluate the relationship between the ophthalmic health care and the health state of the patients from a health perspective. A retrospective study of records from ophthalmology departments (OD) and low vision clinics (LVC) from 1985 to 2004. Assessment of the reports was performed based on the International Classification of Functioning, Disability and Health (ICF). Findings were analysed by manifest content analysis with ICF as a framework and using four themes: health care system, procedure examinations, patient's functioning and disability and procedure actions. The records of nine female patients (aged 25-39 years, 1985) with USH I were selected from the national database of USH. A great number of notes were collected (OD 344 and LVC 566). Procedure examinations were exclusively oriented towards body structure and function. All patients showed aggravated visual impairment over and above the hearing and vestibular impairment. Procedure actions were oriented towards environmental factors. No correlation was found between procedures performed and patient's experience of disability. The high degree of resource allocation was not correlated to the patients' impairment. The study indicates that the ophthalmic health care was characterised by inefficiency. This conclusion is very serious because patients very likely face severe disability and emotional difficulties. ICF is ought to be incorporated in ophthalmic health care strategy to improve the health care.

Synthesis and Self-Assembly of Cellulose Microfibrils from Reconstituted Cellulose Synthase1[OPEN

Science.gov (United States)

Purushotham, Pallinti; Fang, Chao; Maranas, Cassandra; Bulone, Vincent

2017-01-01

Cellulose, the major component of plant cell walls, can be converted to bioethanol and is thus highly studied. In plants, cellulose is produced by cellulose synthase, a processive family-2 glycosyltransferase. In plant cell walls, individual β-1,4-glucan chains polymerized by CesA are assembled into microfibrils that are frequently bundled into macrofibrils. An in vitro system in which cellulose is synthesized and assembled into fibrils would facilitate detailed study of this process. Here, we report the heterologous expression and partial purification of His-tagged CesA5 from Physcomitrella patens. Immunoblot analysis and mass spectrometry confirmed enrichment of PpCesA5. The recombinant protein was functional when reconstituted into liposomes made from yeast total lipid extract. The functional studies included incorporation of radiolabeled Glc, linkage analysis, and imaging of cellulose microfibril formation using transmission electron microscopy. Several microfibrils were observed either inside or on the outer surface of proteoliposomes, and strikingly, several thinner fibrils formed ordered bundles that either covered the surfaces of proteoliposomes or were spawned from liposome surfaces. We also report this arrangement of fibrils made by proteoliposomes bearing CesA8 from hybrid aspen. These observations describe minimal systems of membrane-reconstituted CesAs that polymerize β-1,4-glucan chains that coalesce to form microfibrils and higher-ordered macrofibrils. How these micro- and macrofibrils relate to those found in primary and secondary plant cell walls is uncertain, but their presence enables further study of the mechanisms that govern the formation and assembly of fibrillar cellulosic structures and cell wall composites during or after the polymerization process controlled by CesA proteins. PMID:28768815

Cellulose biosynthesis in higher plants

Directory of Open Access Journals (Sweden)

Krystyna Kudlicka

2014-01-01

Full Text Available Knowledge of the control and regulation of cellulose synthesis is fundamental to an understanding of plant development since cellulose is the primary structural component of plant cell walls. In vivo, the polymerization step requires a coordinated transport of substrates across membranes and relies on delicate orientations of the membrane-associated synthase complexes. Little is known about the properties of the enzyme complexes, and many questions about the biosynthesis of cell wall components at the cell surface still remain unanswered. Attempts to purify cellulose synthase from higher plants have not been successful because of the liability of enzymes upon isolation and lack of reliable in vitro assays. Membrane preparations from higher plant cells incorporate UDP-glucose into a glucan polymer, but this invariably turns out to be predominantly β -1,3-linked rather than β -1,4-linked glucans. Various hypotheses have been advanced to explain this phenomenon. One idea is that callose and cellulose-synthase systems are the same, but cell disruption activates callose synthesis preferentially. A second concept suggests that a regulatory protein as a part of the cellulose-synthase complex is rapidly degraded upon cell disruption. With new methods of enzyme isolation and analysis of the in vitro product, recent advances have been made in the isolation of an active synthase from the plasma membrane whereby cellulose synthase was separated from callose synthase.

21 CFR 172.872 - Methyl ethyl cellulose.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Methyl ethyl cellulose. 172.872 Section 172.872... CONSUMPTION Multipurpose Additives § 172.872 Methyl ethyl cellulose. The food additive methyl ethyl cellulose... a cellulose ether having the general formula [C6H(10 -x-y)O5(CH3)x(C2H5)y]n, where x is the number...

Ionic liquid processing of cellulose.

Science.gov (United States)

Wang, Hui; Gurau, Gabriela; Rogers, Robin D

2012-02-21

Utilization of natural polymers has attracted increasing attention because of the consumption and over-exploitation of non-renewable resources, such as coal and oil. The development of green processing of cellulose, the most abundant biorenewable material on Earth, is urgent from the viewpoints of both sustainability and environmental protection. The discovery of the dissolution of cellulose in ionic liquids (ILs, salts which melt below 100 °C) provides new opportunities for the processing of this biopolymer, however, many fundamental and practical questions need to be answered in order to determine if this will ultimately be a green or sustainable strategy. In this critical review, the open fundamental questions regarding the interactions of cellulose with both the IL cations and anions in the dissolution process are discussed. Investigations have shown that the interactions between the anion and cellulose play an important role in the solvation of cellulose, however, opinions on the role of the cation are conflicting. Some researchers have concluded that the cations are hydrogen bonding to this biopolymer, while others suggest they are not. Our review of the available data has led us to urge the use of more chemical units of solubility, such as 'g cellulose per mole of IL' or 'mol IL per mol hydroxyl in cellulose' to provide more consistency in data reporting and more insight into the dissolution mechanism. This review will also assess the greenness and sustainability of IL processing of biomass, where it would seem that the choices of cation and anion are critical not only to the science of the dissolution, but to the ultimate 'greenness' of any process (142 references).

Ocular and systemic pharmacokinetics of lidocaine hydrochloride ophthalmic gel in rabbits after topical ocular administration.

Science.gov (United States)

Liu, Bing; Ding, Li; Xu, Xiaowen; Lin, Hongda; Sun, Chenglong; You, Linjun

2015-12-01

Lidocaine hydrochloride ophthalmic gel is a novel ophthalmic preparation for topical ocular anesthesia. The study is aimed at evaluating the ocular and systemic pharmacokinetics of lidocaine hydrochloride 3.5 % ophthalmic gel in rabbits after ocular topical administration. Thirty-six rabbits were randomly placed in 12 groups (3 rabbits per group). The rabbits were quickly killed according to their groups at 0 (predose), 0.0833, 0.167, 0.333, 0.667, 1, 1.5, 2, 3, 4, 6, and 8 h postdose and then the ocular tissue and plasma samples were collected. All the samples were analyzed by a validated LC-MS/MS method. The test result showed that the maximum concentration (C max) of lidocaine in different ocular tissues and plasma were all achieved within 20 min after drug administration, and the data of C max were (2,987 ± 1814) μg/g, (44.67 ± 12.91) μg/g, (26.26 ± 7.19) μg/g, (11,046 ± 2,734) ng/mL, and (160.3 ± 61.0) ng/mL for tear fluid, cornea, conjunctiva, aqueous humor, and plasma, respectively. The data of the elimination half-life in these tissues were 1.5, 3.2, 3.5, 1.9, and 1.7 h for tear fluid, cornea, conjunctiva, aqueous humor, and plasma, respectively. The intraocular lidocaine levels were significantly higher than that in plasma, and the elimination half-life of lidocaine in cornea, conjunctiva, and aqueous humor was relatively longer than that in tear fluid and plasma. The high intraocular penetration, low systemic exposure, and long duration in the ocular tissues suggested lidocaine hydrochloride 3.5 % ophthalmic gel as an effective local anesthetic for ocular anesthesia during ophthalmic procedures.

Sequence and structural analysis of the chitinase insertion domain reveals two conserved motifs involved in chitin-binding.

Directory of Open Access Journals (Sweden)

Hai Li

2010-01-01

Full Text Available Chitinases are prevalent in life and are found in species including archaea, bacteria, fungi, plants, and animals. They break down chitin, which is the second most abundant carbohydrate in nature after cellulose. Hence, they are important for maintaining a balance between carbon and nitrogen trapped as insoluble chitin in biomass. Chitinases are classified into two families, 18 and 19 glycoside hydrolases. In addition to a catalytic domain, which is a triosephosphate isomerase barrel, many family 18 chitinases contain another module, i.e., chitinase insertion domain. While numerous studies focus on the biological role of the catalytic domain in chitinase activity, the function of the chitinase insertion domain is not completely understood. Bioinformatics offers an important avenue in which to facilitate understanding the role of residues within the chitinase insertion domain in chitinase function.Twenty-seven chitinase insertion domain sequences, which include four experimentally determined structures and span five kingdoms, were aligned and analyzed using a modified sequence entropy parameter. Thirty-two positions with conserved residues were identified. The role of these conserved residues was explored by conducting a structural analysis of a number of holo-enzymes. Hydrogen bonding and van der Waals calculations revealed a distinct subset of four conserved residues constituting two sequence motifs that interact with oligosaccharides. The other conserved residues may be key to the structure, folding, and stability of this domain.Sequence and structural studies of the chitinase insertion domains conducted within the framework of evolution identified four conserved residues which clearly interact with the substrates. Furthermore, evolutionary studies propose a link between the appearance of the chitinase insertion domain and the function of family 18 chitinases in the subfamily A.

Paper actuators made with cellulose and hybrid materials.

Science.gov (United States)

Kim, Jaehwan; Yun, Sungryul; Mahadeva, Suresha K; Yun, Kiju; Yang, Sang Yeol; Maniruzzaman, Mohammad

2010-01-01

Recently, cellulose has been re-discovered as a smart material that can be used as sensor and actuator materials, which is termed electro-active paper (EAPap). This paper reports recent advances in paper actuators made with cellulose and hybrid materials such as multi-walled carbon nanotubes, conducting polymers and ionic liquids. Two distinct actuator principles in EAPap actuators are demonstrated: piezoelectric effect and ion migration effect in cellulose. Piezoelectricity of cellulose EAPap is quite comparable with other piezoelectric polymers. But, it is biodegradable, biocompatible, mechanically strong and thermally stable. To enhance ion migration effect in the cellulose, polypyrrole conducting polymer and ionic liquids were nanocoated on the cellulose film. This hybrid cellulose EAPap nanocomposite exhibits durable bending actuation in an ambient humidity and temperature condition. Fabrication, characteristics and performance of the cellulose EAPap and its hybrid EAPap materials are illustrated. Also, its possibility for remotely microwave-driven paper actuator is demonstrated.

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)

Paradigm Shifts in Ophthalmic Diagnostics.

Science.gov (United States)

Sebag, J; Sadun, Alfredo A; Pierce, Eric A

2016-08-01

Future advances in ophthalmology will see a paradigm shift in diagnostics from a focus on dysfunction and disease to better measures of psychophysical function and health. Practical methods to define genotypes will be increasingly important and non-invasive nanotechnologies are needed to detect molecular changes that predate histopathology. This is not a review nor meant to be comprehensive. Specific topics have been selected to illustrate the principles of important paradigm shifts that will influence the future of ophthalmic diagnostics. It is our impression that future evaluation of vision will go beyond visual acuity to assess ocular health in terms of psychophysical function. The definition of disease will incorporate genotype into what has historically been a phenotype-centric discipline. Non-invasive nanotechnologies will enable a paradigm shift from disease detection on a cellular level to a sub-cellular molecular level. Vision can be evaluated beyond visual acuity by measuring contrast sensitivity, color vision, and macular function, as these provide better insights into the impact of aging and disease. Distortions can be quantified and the psychophysical basis of vision can be better evaluated than in the past by designing tests that assess particular macular cell function(s). Advances in our understanding of the genetic basis of eye diseases will enable better characterization of ocular health and disease. Non-invasive nanotechnologies can assess molecular changes in the lens, vitreous, and macula that predate visible pathology. Oxygen metabolism and circulatory physiology are measurable indices of ocular health that can detect variations of physiology and early disease. This overview of paradigm shifts in ophthalmology suggests that the future will see significant improvements in ophthalmic diagnostics. The selected topics illustrate the principles of these paradigm shifts and should serve as a guide to further research and development. Indeed

Effect of ionizing radiation on starch and cellulose

International Nuclear Information System (INIS)

Klenha, J.; Bockova, J.

1973-09-01

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)

High Performance Regenerated Cellulose Membranes from Trimethylsilyl Cellulose

KAUST Repository

Ali, Ola

2013-01-01

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

Application and study of conjunctival sac disinfectants in ophthalmic surgeries

Directory of Open Access Journals (Sweden)

Yan-Fei Luo

2016-01-01

Full Text Available Postoperative endophthalmitis is the most serious complications of ophthalmic surgeries. Conjunctival sac disinfection is currently recognized as an effectively important way to reduce the risk of endophthalmitis. At present, there are some disinfectants has been used in clinic or in the researches:mercury agent, gentamicin, povidone iodine and acid electrolytic water. All kinds of disinfectants play the role of disinfection by different ways. Povidone iodine is the most widely used conjunctival sac disinfectant. Mercurial and gentamicin have been rarely used because they pollute the environment, are easy to cause drug resistant bacteria, localized side reactions and so on. The acid electrolyte water is not used in clinic at present. With the popularization and development of the ophthalmic surgeries, the ophthalmologists have become more and more concerned about the postoperative eye comfort, the research and application of conjunctival sac disinfectant in the future will continue to be updated and developed.

Optimization and evaluation of thermoresponsive diclofenac sodium ophthalmic in situ gels.

Science.gov (United States)

Asasutjarit, Rathapon; Thanasanchokpibull, Suthira; Fuongfuchat, Asira; Veeranondha, Sukitaya

2011-06-15

This work was conducted to optimize and evaluate Pluronic F127-based thermoresponsive diclofenac sodium ophthalmic in situ gels (DS in situ gel). They were prepared by cold method and investigated their physicochemical properties i.e., pH, flow ability, sol-gel transition temperature, gelling capacity and rheological properties. An optimized formulation was selected and investigated its physicochemical properties before and after autoclaving, eye irritation potency in SIRC cells and rabbits. In vivo ophthalmic absorption was performed in rabbits. It was found that physicochemical properties of DS in situ gels were affected by formulation compositions. Increment of Pluronic F127 content decreased sol-gel transition temperature of the products while increase in Pluronic F68 concentration tended to increase sol-gel transition temperature. In this study, Carbopol 940 did not affect sol-gel transition temperature but it affected transparency, pH, and gelling capacity of the products. The optimized formulation exhibited sol-gel transition at 32.6 ± 1.1 °C with pseudoplastic flow behavior. It was lost diclofenac sodium content during autoclaving. However, it was accepted as safe for ophthalmic use and could increase diclofenac sodium bioavailability in aqueous humor significantly. In conclusion, the optimized DS in situ gel had potential for using as an alternative to the conventional diclofenac sodium eye drop. However, autoclaving was not a suitable sterilization method for this product. Copyright © 2011 Elsevier B.V. All rights reserved.

Local toxicity of benzalkonium chloride in ophthalmic solutions following repeated applications.

Science.gov (United States)

Okahara, Akihiko; Kawazu, Kouichi

2013-01-01

We performed repeated toxicity studies of benzalkonium chloride (BAK)-containing vehicles of ophthalmic solutions in monkeys and rabbits to assess the local toxicity of BAK after repeated applications on the ocular surface. Local toxicity of BAK was evaluated by toxicity studies in which a 0.01% BAK-containing vehicle was applied twice/day for 52 weeks, 4 times/day for 39 weeks, or 6 times/day for 13 weeks, or in which a 0.005% BAK-containing vehicle was applied 6 times/day for 52 weeks or twice/day for 4 weeks in monkeys. Local toxicity of BAK was also evaluated where a 0.01% BAK-containing vehicle was applied 6 times/day for 6 weeks, or a 0.005% BAK-containing vehicle was applied twice/day for 39 weeks or 8 times/day for 4 weeks in rabbits. These doses were chosen because BAK is generally used at concentrations up to 0.01% in ophthalmic solutions. The BAK-containing vehicle did not cause ophthalmological changes suggestive of irritation, allergy, or corneal damage. We also did not observe any histopathological changes in the eyeball, eyelid, lacrimal gland, and nasal cavity, with repeated applications of BAK for up to 52 weeks, up to 8 times/day, or at concentrations up to 0.01%, in monkeys and rabbits. Our results suggest that BAK in concentrations up to 0.01% in ophthalmic solution is non-toxic to the eyeball, its accessory organs, and the nasal cavity after long repeated applications.

[Sinus pericranii associated to spontaneous thrombosis of the ophthalmic vein: neuroimaging studies].

Science.gov (United States)

Murias, E; Villota, E; Saiz, A; Gil, A; Calleja, S

2009-01-01

Sinus pericranii is an abnormal venous communication between the intracranial dural sinuses and epicranial venous dilatations. The periorbital location is uncommon; spontaneous partial thromboses of the subcutaneous varices have been reported in association with local signs and symptoms; however, to our knowledge there are no reports of sinus pericranii associated to thrombosis in the ophthalmic vein. Sinus pericranii is related to arteriovenous and lymphatic-venous malformations. We present the case of a patient with a generalized and diffuse disorder of venous drainage that affected the right cerebral hemisphere who presented at the emergency department with ophthalmologic signs and symptoms after thrombosis of the superior ophthalmic vein and who had three sinus pericranii located in the frontal, parietal, and occipital areas.

Preparation of membranes from cellulose obtained of sugarcane bagasse

International Nuclear Information System (INIS)

Pereira, Paulo Henrique Fernandes; Cioffi, Maria Odila Hilario; Voorwald, Herman Jacobus Cornelis; Pinho, Maria Noberta de; Silva, Maria Lucia Caetano Pinto da

2010-01-01

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)

Overview of Cellulose Nanomaterials, Their Capabilities and Applications

Science.gov (United States)

Robert J. Moon; Gregory T. Schueneman; John Simonsen

2016-01-01

Cellulose nanomaterials (CNs) are a new class of cellulose particles with properties and functionalities distinct from molecular cellulose and wood pulp, and as a result, they are being developed for applications that were once thought impossible for cellulosic materials. Momentum is growing in CN research and development, and commercialization in this field is...

Method of forming an electrically conductive cellulose composite

Science.gov (United States)

Evans, Barbara R [Oak Ridge, TN; O'Neill, Hugh M [Knoxville, TN; Woodward, Jonathan [Ashtead, GB

2011-11-22

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.

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.

Radiation pretreatment of cellulose for energy production

International Nuclear Information System (INIS)

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

1983-01-01

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)

Cellulose binding domain proteins

Science.gov (United States)

Shoseyov, Oded; Shpiegl, Itai; Goldstein, Marc; Doi, Roy

1998-01-01

A cellulose binding domain (CBD) having a high affinity for crystalline cellulose and chitin is disclosed, along with methods for the molecular cloning and recombinant production thereof. Fusion products comprising the CBD and a second protein are likewise described. A wide range of applications are contemplated for both the CBD and the fusion products, including drug delivery, affinity separations, and diagnostic techniques.

Properties of microcrystalline cellulose obtained from coconut ...

African Journals Online (AJOL)

The study revealed that the cellulose material compares favourably with Avicel PH 101 as well as official requirement specified in the British Pharmacopoeia 1993 for microcrystalline cellulose. Keywords: Coconut fruit fibre, microcrystalline cellulose, powder properties. Journal of Pharmacy and Bioresources Vol. 3 (1) 2006: ...

Structure/Function Analysis of Cotton-Based Peptide-Cellulose Conjugates: Spatiotemporal/Kinetic Assessment of Protease Aerogels Compared to Nanocrystalline and Paper Cellulose

Directory of Open Access Journals (Sweden)

J. Vincent Edwards

2018-03-01

Full Text Available Nanocellulose has high specific surface area, hydration properties, and ease of derivatization to prepare protease sensors. A Human Neutrophil Elastase sensor designed with a nanocellulose aerogel transducer surface derived from cotton is compared with cotton filter paper, and nanocrystalline cellulose versions of the sensor. X-ray crystallography was employed along with Michaelis–Menten enzyme kinetics, and circular dichroism to contrast the structure/function relations of the peptide-cellulose conjugate conformation to enzyme/substrate binding and turnover rates. The nanocellulosic aerogel was found to have a cellulose II structure. The spatiotemporal relation of crystallite surface to peptide-cellulose conformation is discussed in light of observed enzyme kinetics. A higher substrate binding affinity (Km of elastase was observed with the nanocellulose aerogel and nanocrystalline peptide-cellulose conjugates than with the solution-based elastase substrate. An increased Km observed for the nanocellulosic aerogel sensor yields a higher enzyme efficiency (kcat/Km, attributable to binding of the serine protease to the negatively charged cellulose surface. The effect of crystallite size and β-turn peptide conformation are related to the peptide-cellulose kinetics. Models demonstrating the orientation of cellulose to peptide O6-hydroxymethyl rotamers of the conjugates at the surface of the cellulose crystal suggest the relative accessibility of the peptide-cellulose conjugates for enzyme active site binding.

Structure/Function Analysis of Cotton-Based Peptide-Cellulose Conjugates: Spatiotemporal/Kinetic Assessment of Protease Aerogels Compared to Nanocrystalline and Paper Cellulose

Science.gov (United States)

Edwards, J. Vincent; Fontenot, Krystal; Liebner, Falk; Pircher, Nicole Doyle nee; French, Alfred D.; Condon, Brian D.

2018-01-01

Nanocellulose has high specific surface area, hydration properties, and ease of derivatization to prepare protease sensors. A Human Neutrophil Elastase sensor designed with a nanocellulose aerogel transducer surface derived from cotton is compared with cotton filter paper, and nanocrystalline cellulose versions of the sensor. X-ray crystallography was employed along with Michaelis–Menten enzyme kinetics, and circular dichroism to contrast the structure/function relations of the peptide-cellulose conjugate conformation to enzyme/substrate binding and turnover rates. The nanocellulosic aerogel was found to have a cellulose II structure. The spatiotemporal relation of crystallite surface to peptide-cellulose conformation is discussed in light of observed enzyme kinetics. A higher substrate binding affinity (Km) of elastase was observed with the nanocellulose aerogel and nanocrystalline peptide-cellulose conjugates than with the solution-based elastase substrate. An increased Km observed for the nanocellulosic aerogel sensor yields a higher enzyme efficiency (kcat/Km), attributable to binding of the serine protease to the negatively charged cellulose surface. The effect of crystallite size and β-turn peptide conformation are related to the peptide-cellulose kinetics. Models demonstrating the orientation of cellulose to peptide O6-hydroxymethyl rotamers of the conjugates at the surface of the cellulose crystal suggest the relative accessibility of the peptide-cellulose conjugates for enzyme active site binding. PMID:29534033

Enhancement of Cellulose Degradation by Cattle Saliva

Science.gov (United States)

Seki, Yasutaka; Kikuchi, Yukiko; Kimura, Yoshihiro; Yoshimoto, Ryo; Takahashi, Masatoshi; Aburai, Kenichi; Kanai, Yoshihiro; Ruike, Tatsushi; Iwabata, Kazuki; Sugawara, Fumio; Sakai, Hideki; Abe, Masahiko; Sakaguchi, Kengo

2015-01-01

Saccharification of cellulose is a promising technique for producing alternative source of energy. However, the efficiency of conversion of cellulose into soluble sugar using any currently available methodology is too low for industrial application. Many additives, such as surfactants, have been shown to enhance the efficiency of cellulose-to-sugar conversion. In this study, we have examined first whether cattle saliva, as an additive, would enhance the cellulase-catalyzed hydrolysis of cellulose, and subsequently elucidated the mechanism by which cattle saliva enhanced this conversion. Although cattle saliva, by itself, did not degrade cellulose, it enhanced the cellulase-catalyzed degradation of cellulose. Thus, the amount of reducing sugar produced increased approximately 2.9-fold by the addition of cattle saliva. We also found that non-enzymatic proteins, which were present in cattle saliva, were responsible for causing the enhancement effect. Third, the mechanism of cattle saliva mediated enhancement of cellulase activity was probably similar to that of the canonical surfactants. Cattle saliva is available in large amounts easily and cheaply, and it can be used without further purification. Thus, cattle saliva could be a promising additive for efficient saccharification of cellulose on an industrial scale. PMID:26402242

One-step Fabrication of Cellulose/Graphene Conductive Paper

Institute of Scientific and Technical Information of China (English)

KaiWen Mou; LuMing Yang; HuangWei Xiong; RuiTao Cha

2017-01-01

In this study,a straightforward,one-step wet-end formation process was employed to prepare cellulose/graphene conductive paper for antistatic packing materials.Cationic polyacrylamide was introduced into the cellulose/graphene slurry to improve the graphene loading on the surfaces of the cellulose fibers.The effect of the super calender process on the properties of the cellulose/graphene conductive paper was investigated.When 55 wt％ graphene was added,the volume resistivity of the cellulose/graphene conductive paper was 94.70 Ω·cm,decreasing to 35.46 Ω·cm after the super calender process.The cellulose/graphene conductive paper possessed excellent anti-static ability and could be used as an anti-static material.

Antimicrobial activity of a new preservative for multiuse ophthalmic solutions.

Science.gov (United States)

Ghelardi, Emilia; Celandroni, Francesco; Gueye, Sokhna A; Salvetti, Sara; Campa, Mario; Senesi, Sonia

2013-01-01

The aim of this study was to examine the antimicrobial activity and the preservative efficacy of a novel preservative solution containing sodium hydroxymethyl glycinate (SHMG) and edetate disodium (EDTA), which is used for preservation of some commercial ophthalmic formulations. In vitro susceptibility assays were performed against several gram-positive (Staphylococcus aureus, Staphylococcus epidermidis, and Bacillus cereus) and gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria representative of the microbial flora of epithelial surfaces or colonizing the conjunctiva, as well as against Candida albicans and Aspergillus niger. Using different concentrations of SHMG alone or in combination with EDTA, the minimal inhibitory and microbicidal concentrations against these organisms were assessed. In addition, 8 brands of multidose eye drops containing 0.002% SHMG and 0.1% EDTA as preservative were tested for antimicrobial activity using the antimicrobial effectiveness test recommended by the international pharmacopoeias. The minimal inhibitory and bactericidal/fungicidal concentration values of SHMG ranged from 0.0025% to 0.0125% for bacteria and from 0.125% to 0.50% for mold and yeast. Susceptibility testing demonstrated that the addition of EDTA substantially increased the SHMG activity against all bacterial and fungal strains. The preservative effectiveness test was applied to commercial eye drops. All the drop solutions met the criteria reported by the U.S. Pharmacopeia for parenteral and ophthalmic preparations. All products also satisfied the major acceptance criteria of the European Pharmacopeia with respect to the antifungal activity. With regard to the antibacterial activity, the less-stringent criteria of the European Pharmacopeia were fulfilled. The present study demonstrates the efficacy of a novel preservative for ophthalmic solutions (SHMG/EDTA) and its activity in protecting selected commercial artificial tears against microbial

Cellulose nanomaterials review: structure, properties and nanocomposites

Science.gov (United States)

Robert J. Moon; Ashlie Martini; John Nairn; John Simonsen; Jeff Youngblood

2011-01-01

This critical review provides a processing-structure-property perspective on recent advances in cellulose nanoparticles and composites produced from them. It summarizes cellulose nanoparticles in terms of particle morphology, crystal structure, and properties. Also described are the self-assembly and rheological properties of cellulose nanoparticle suspensions. The...

Cellulose powder from Cladophora sp. algae.

Science.gov (United States)

Ek, R; Gustafsson, C; Nutt, A; Iversen, T; Nyström, C

1998-01-01

The surface are and crystallinity was measured on a cellulose powder made from Cladophora sp. algae. The algae cellulose powder was found to have a very high surface area (63.4 m2/g, N2 gas adsorption) and build up of cellulose with a high crystallinity (approximately 100%, solid state NMR). The high surface area was confirmed by calculations from atomic force microscope imaging of microfibrils from Cladophora sp. algae.

Using carboxylated nanocrystalline cellulose as an additive in cellulosic paper and poly (vinyl alcohol) fiber paper.

Science.gov (United States)

Cha, Ruitao; Wang, Chengyu; Cheng, Shaoling; He, Zhibin; Jiang, Xingyu

2014-09-22

Specialty paper (e.g. cigarette paper and battery diaphragm paper) requires extremely high strength properties. The addition of strength agents plays an important role in increasing strength properties of paper. Nanocrystalline cellulose (NCC), or cellulose whiskers, has the potential to enhance the strength properties of paper via improving inter-fibers bonding. This paper was to determine the potential of using carboxylated nanocrystalline cellulose (CNCC) to improve the strength properties of paper made of cellulosic fiber or poly (vinyl alcohol) (PVA) fiber. The results indicated that the addition of CNCC can effectively improve the strength properties. At a CNCC dosage of 0.7%, the tear index and tensile index of the cellulosic paper reached the maximum of 12.8 mN m2/g and 100.7 Nm/g, respectively. More importantly, when increasing the CNCC dosage from 0.1 to 1.0%, the tear index and tensile index of PVA fiber paper were increased by 67.29%, 22.55%, respectively. Copyright © 2014 Elsevier Ltd. All rights reserved.

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.

Preparation of carboxymethyl cellulose produced from purun tikus (Eleocharis dulcis)

Science.gov (United States)

Sunardi, Febriani, Nina Mutia; Junaidi, Ahmad Budi

2017-08-01

Sodium carboxymethyl cellulose (Na-CMC) is one of the important modified cellulose, a water-soluble cellulose, which is widely used in many application of food, pharmaceuticals, detergent, paper coating, dispersing agent, and others. The main raw material of modified cellulose is cellulose from wood and cotton. Recently, much attention has been attracted to the use of various agriculture product and by-product, grass, and residual biomass as cellulose and modified cellulose source for addressing an environmental and economic concern. Eleocharis dulcis, commonly known as purun tikus (in Indonesia), is a native aquatic plant of swamp area (wetland) in Kalimantan, which consists of 30-40% cellulose. It is significantly considered as one of the alternative resources for cellulose. The aims of present study were to isolate cellulose from E. dulcis and then to synthesise Na-CMC from isolated cellulose. Preparation of carboxymethyl cellulose from E. dulcis was carried out by an alkalization and etherification process of isolated cellulose, using various concentration of sodium hydroxide (NaOH) and monochloroacetic acid (MCA). The results indicated that the optimum reaction of alkalization was reached at 20% NaOH and etherification at the mass fraction ratio of MCA to cellulose 1.0. The optimum reaction has the highest solubility and degree of substitution. The carboxymethylation process of cellulose was confirmed by Fourier Transform Infrared spectroscopy (FTIR). In addition, changes in crystallinity of cellulose and Na-CMC were evaluated by X-ray diffraction (XRD).

Biodegradation evaluation of bacterial cellulose, vegetable cellulose and poly (3-hydroxybutyrate in soil

Directory of Open Access Journals (Sweden)

Suellen Brasil Schröpfer

2015-04-01

Full Text Available In recent years, the inappropriate disposal of polymeric materials has increased due to industrial development and increase of population consumption. This problem may be minimized by using biodegradable polymers, such as bacterial cellulose and poly(hydroxybutyrate, from renewable resources. This work was aimed at monitoring and evaluating degradation of bacterial cellulose, vegetable cellulose and poly(3-hydroxybutyrate using Thermogravimetric Analysis and Scanning Electron Microscopy. Controlled mass polymer samples were buried in pots containing soil. Samples were removed in 30 day intervals up to 180 days. The results show that the mass of the polymer increased in the first month when in contact with the soil but then it was degraded as evidenced by mass loss and changes on the sample surface.

Carbonized cellulose paper as an effective interlayer in lithium-sulfur batteries

International Nuclear Information System (INIS)

Li, Shiqi; Ren, Guofeng; Hoque, Md Nadim Ferdous; Dong, Zhihua; Warzywoda, Juliusz; Fan, Zhaoyang

2017-01-01

Highlights: • A facile and economical method to fabricate interlayer for high-performance lithium-sulfur battery was demonstrated. • The performance of lithium-sulfur batteries without and with interlayer was compared. • The mechanism for the function of interlayer was explained. - Abstract: One of the several challenging problems hampering lithium-sulfur (Li-S) battery development is the so-called shuttling effect of the highly soluble intermediates (Li_2S_8–Li_2S_6). Using an interlayer inserted between the sulfur cathode and the separator to capture and trap these soluble intermediates has been found effective in diminishing this effect. Previously, most reported interlayer membranes were synthesized in a complex and expensive process, and might not be suitable for practical cheap batteries. Herein, a facile method is reported to pyrolyze the commonly used cellulose filter paper into highly flexible and conductive carbon fiber paper. When used as an interlayer, such a carbon paper can improve the cell capacity by several folds through trapping the soluble polysulfides. The enhanced electronic conductivity of the cathode, due to the interlayer, also significantly improves the cell rate performance. In addition, it was demonstrated that such an interlayer can also effectively mitigate the self-discharge problem of the Li-S batteries. This study indicates that the cost-effective pyrolyzed cellulose paper has potential as interlayer for practical Li-S batteries.

Carbonized cellulose paper as an effective interlayer in lithium-sulfur batteries

Energy Technology Data Exchange (ETDEWEB)

Li, Shiqi; Ren, Guofeng; Hoque, Md Nadim Ferdous [Department of Electrical and Computer Engineering and Nano Tech Center, Texas Tech University, Lubbock, TX 79409 (United States); Dong, Zhihua [Hangzhou Dianzi University, No. 1158, 2nd Street, Xiasha Higher Education District, Hangzhou City, Zhejiang Province (China); Warzywoda, Juliusz [Materials Characterization Center, Whitacre College of Engineering, Texas Tech University, Lubbock, TX 79409 (United States); Fan, Zhaoyang, E-mail: zhaoyang.fan@ttu.edu [Department of Electrical and Computer Engineering and Nano Tech Center, Texas Tech University, Lubbock, TX 79409 (United States)

2017-02-28

Highlights: • A facile and economical method to fabricate interlayer for high-performance lithium-sulfur battery was demonstrated. • The performance of lithium-sulfur batteries without and with interlayer was compared. • The mechanism for the function of interlayer was explained. - Abstract: One of the several challenging problems hampering lithium-sulfur (Li-S) battery development is the so-called shuttling effect of the highly soluble intermediates (Li{sub 2}S{sub 8}–Li{sub 2}S{sub 6}). Using an interlayer inserted between the sulfur cathode and the separator to capture and trap these soluble intermediates has been found effective in diminishing this effect. Previously, most reported interlayer membranes were synthesized in a complex and expensive process, and might not be suitable for practical cheap batteries. Herein, a facile method is reported to pyrolyze the commonly used cellulose filter paper into highly flexible and conductive carbon fiber paper. When used as an interlayer, such a carbon paper can improve the cell capacity by several folds through trapping the soluble polysulfides. The enhanced electronic conductivity of the cathode, due to the interlayer, also significantly improves the cell rate performance. In addition, it was demonstrated that such an interlayer can also effectively mitigate the self-discharge problem of the Li-S batteries. This study indicates that the cost-effective pyrolyzed cellulose paper has potential as interlayer for practical Li-S batteries.

Bacterial cellulose/boehmite composites

International Nuclear Information System (INIS)

Salvi, Denise T.B. de; Barud, Hernane S.; Messaddeq, Younes; Ribeiro, Sidney J.L.; Caiut, Jose Mauricio A.

2011-01-01

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)

Ophthalmic Skills Assessment of Primary Health Care Workers at ...

African Journals Online (AJOL)

Proficiency in the basic ophthalmic skills is a cri cal factor in the effec ve delivery of eye care services at the primary level of care. The aim of the study was to assess the ability of ... out visual acuity test and correctly iden fy cataract and conjunc vi s using pictures of eye condi ons and ..... Medical Laboratory Technician.

Method of inserting fuel rod

International Nuclear Information System (INIS)

Kamimoto, Shuji; Imoo, Makoto; Tsuchida, Kenji.

1991-01-01

The present invention concerns a method of inserting a fuel rod upon automatic assembling, automatic dismantling and reassembling of a fuel assembly in a light water moderated reactor, as well as a device and components used therefor. That is, a fuel rod is inserted reliably to an aimed point of insertion by surrounding the periphery of the fuel rod to be inserted with guide rods, and thereby suppressing the movement of the fuel rod during insertion. Alternatively, a fuel rod is inserted reliably to a point of insertion by inserting guide rods at the periphery of the point of insertion for the fuel rod to be inserted thereby surrounding the point of insertion with the guide rods or fuel rods. By utilizing fuel rods already present in the fuel assembly as the guide rods described above, the fuel rod can be inserted reliably to the point of insertion with no additional devices. Dummy fuel rods are previously inserted in a fuel assembly which are then utilized as the above-mentioned guide rods to accurately insert the fuel rod to the point of insertion. (I.S.)

Coarse-grained model for the interconversion between different crystalline cellulose allomorphs

Energy Technology Data Exchange (ETDEWEB)

Langan, Paul [ORNL

2012-01-01

We present the results of Langevin dynamics simulations on a coarse grained model for crystalline cellulose. In particular, we analyze two different cellulose crystalline forms: cellulose I (the natural form of cellulose) and cellulose IIII (obtained after cellulose I is treated with anhydrous liquid ammonia). Cellulose IIII has been the focus of wide interest in the field of cellulosic biofuels as it can be efficiently hydrolyzed to glucose (its enzymatic degradation rates are up to 5 fold higher than those of cellulose I ). In turn, glucose can eventually be fermented into fuels. The coarse-grained model presented in this study is based on a simplified geometry and on an effective potential mimicking the changes in both intracrystalline hydrogen bonds and stacking interactions during the transition from cellulose I to cellulose IIII. The model accurately reproduces both structural and thermomechanical properties of cellulose I and IIII. The work presented herein describes the structural transition from cellulose I to cellulose IIII as driven by the change in the equilibrium state of two degrees of freedom in the cellulose chains. The structural transition from cellulose I to cellulose IIII is essentially reduced to a search for optimal spatial arrangement of the cellulose chains.

Alpha autoradiography by cellulose nitrate layer

International Nuclear Information System (INIS)

Simonovic, J.; Vukovic, J.; Antanasijevic, R.

1977-01-01

From domestic cellulose nitrate bulk material thin layers for α-particle autoradiography were prepared. An artificial test specimen of a uniformly alpha labelled grid source was used. The efficiency of autoradiography by cellulose nitrate was calculated comparing with data from an Ilford K2 nuclear emulsion exposed under the same conditions as the cellulose nitrate film. The resolution was determined as the distance from grid pitch edge at which the track density fell considerably. (Auth.)

Dissolution Behavior of Cellulose in IL + DMSO Solvent: Effect of Alkyl Length in Imidazolium Cation on Cellulose Dissolution

Directory of Open Access Journals (Sweden)

Airong Xu

2015-01-01

Full Text Available Four cellulose solvents including [C2mim][CH3COO] + DMSO, [C4mim][CH3COO] + DMSO, [C6mim][CH3COO] + DMSO, and [C8mim][CH3COO] + DMSO were prepared by adding dimethyl sulfoxide DMSO in 1-ethyl-3-methylimidazolium acetate [C2mim][CH3COO], 1-butyl-3-methylimidazolium acetate [C4mim][CH3COO], 1-hexyl-3-methylimidazolium acetate [C6mim][CH3COO], and 1-octyl-3-methylimidazolium acetate [C8mim][CH3COO], respectively. The solubilities of cellulose in these solvents were determined at 25°C. The effect of the alkyl chain length in imidazolium cation on cellulose solubility was investigated. With increasing alkyl chain length in imidazolium cation, the solubility of cellulose increases, but further increase in alkyl chain length results in decreases in cellulose.

Characterization of blend hydrogels based on plasticized starch/cellulose acetate/carboxymethyl cellulose synthesized by electron beam irradiation

Energy Technology Data Exchange (ETDEWEB)

Senna, Magdy M., E-mail: magdysenna@hotmail.com [Radiation Chemistry Department, National Center for Radiation Research and Technology, Atomic Energy Authority, Cairo (Egypt); Mostafa, Abo El-Khair B. [Chemistry Department, College for Girls, Ain Shams University, Cairo (Egypt); Mahdy, Sanna R.; El-Naggar, Abdel Wahab M. [Radiation Chemistry Department, National Center for Radiation Research and Technology, Atomic Energy Authority, Cairo (Egypt)

2016-11-01

Highlights: • Semi-interpenetrating (IPN) blend hydrogels were synthesized by EB irradiation. • The hydrogels were based on starch/cellulose acetate/carboxymethyl cellulose blends. • The gelation, swelling, thermal and mechanical properties of hydrogels were studied. • The thermal stability was studied by determining kinetic energy by different methods. - Abstract: Blend hydrogels based on aqueous solutions of plasticized starch and different ratios of cellulose acetate (CA) and carboxymethyl cellulose (CMC) were prepared by electron beam irradiation (EB). The blends before and after EB irradiation were characterized by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The physico-chemical properties of blend hydrogels prepared by electron beam irradiation were improved compared to unirradiated blends.

Characterization of blend hydrogels based on plasticized starch/cellulose acetate/carboxymethyl cellulose synthesized by electron beam irradiation

International Nuclear Information System (INIS)

Senna, Magdy M.; Mostafa, Abo El-Khair B.; Mahdy, Sanna R.; El-Naggar, Abdel Wahab M.

2016-01-01

Highlights: • Semi-interpenetrating (IPN) blend hydrogels were synthesized by EB irradiation. • The hydrogels were based on starch/cellulose acetate/carboxymethyl cellulose blends. • The gelation, swelling, thermal and mechanical properties of hydrogels were studied. • The thermal stability was studied by determining kinetic energy by different methods. - Abstract: Blend hydrogels based on aqueous solutions of plasticized starch and different ratios of cellulose acetate (CA) and carboxymethyl cellulose (CMC) were prepared by electron beam irradiation (EB). The blends before and after EB irradiation were characterized by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The physico-chemical properties of blend hydrogels prepared by electron beam irradiation were improved compared to unirradiated blends.

Cellulose Triacetate Synthesis from Cellulosic Wastes by Heterogeneous Reactions

Directory of Open Access Journals (Sweden)

Sherif Shawki Z. Hindi

2015-06-01

Full Text Available Cellulosic fibers from cotton fibers (CF, recycled writing papers (RWP, recycled newspapers (RN, and macerated woody fibers of Leucaena leucocephala (MWFL were acetylated by heterogeneous reactions with glacial acetic acid, concentrated H2SO4, and acetic anhydride. The resultant cellulose triacetate (CTA was characterized for yield and solubility as well as by using 1H-NMR spectroscopy and SEM. The acetylated product (AP yields for CF, RWP, RN, and MWFL were 112, 94, 84, and 73%, respectively. After isolation of pure CTA from the AP, the CTA yields were 87, 80, 68, and 54%. The solubility test for the CTA’s showed a clear solubility in chloroform, as well as mixture of chloroform and methanol (9:1v/v and vice versa for acetone. The degree of substitution (DS values for the CTA’s produced were nearly identical and confirmed the presence of CTA. In addition, the pore diameter of the CTA skeleton ranged from 0.072 to 0.239 µm for RWP and RN, and within the dimension scale of the CTA pinholes confirm the synthesis of CTA. Accordingly, pouring of the AP liquor at 25 °C in distilled water at the end of the acetylation and filtration did not hydrolyze the CTA to cellulose diacetate.

Kinetics of Cellulose Digestion by Fibrobacter succinogenes S85

OpenAIRE

Maglione, G.; Russell, J. B.; Wilson, D. B.

1997-01-01

Growing cultures of Fibrobacter succinogenes S85 digested cellulose at a rapid rate, but nongrowing cells and cell extracts did not have detectable crystalline cellulase activity. Cells that had been growing exponentially on cellobiose initiated cellulose digestion and succinate production immediately, and cellulose-dependent succinate production could be used as an index of enzyme activity against crystalline cellulose. Cells incubated with cellulose never produced detectable cellobiose, and...

Cellulose nanomaterials as green nanoreinforcements for polymer nanocomposites

Science.gov (United States)

Dufresne, Alain

2017-12-01

Unexpected and attractive properties can be observed when decreasing the size of a material down to the nanoscale. Cellulose is no exception to the rule. In addition, the highly reactive surface of cellulose resulting from the high density of hydroxyl groups is exacerbated at this scale. Different forms of cellulose nanomaterials, resulting from a top-down deconstruction strategy (cellulose nanocrystals, cellulose nanofibrils) or bottom-up strategy (bacterial cellulose), are potentially useful for a large number of industrial applications. These include the paper and cardboard industry, use as reinforcing filler in polymer nanocomposites, the basis for low-density foams, additives in adhesives and paints, as well as a wide variety of filtration, electronic, food, hygiene, cosmetic and medical products. This paper focuses on the use of cellulose nanomaterials as a filler for the preparation of polymer nanocomposites. Impressive mechanical properties can be obtained for these materials. They obviously depend on the type of nanomaterial used, but the crucial point is the processing technique. The emphasis is on the melt processing of such nanocomposite materials, which has not yet been properly resolved and remains a challenge. This article is part of a discussion meeting issue `New horizons for cellulose nanotechnology'.

Clinical utility of 3% diquafosol ophthalmic solution in the treatment of dry eyes

Science.gov (United States)

Koh, Shizuka

2015-01-01

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. PMID:26028958

Clinical utility of 3% diquafosol ophthalmic solution in the treatment of dry eyes.

Science.gov (United States)

Koh, Shizuka

2015-01-01

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.

Enhanced Cellulose Degradation Using Cellulase-Nanosphere Complexes

Science.gov (United States)

Blanchette, Craig; Lacayo, Catherine I.; Fischer, Nicholas O.; Hwang, Mona; Thelen, Michael P.

2012-01-01

Enzyme catalyzed conversion of plant biomass to sugars is an inherently inefficient process, and one of the major factors limiting economical biofuel production. This is due to the physical barrier presented by polymers in plant cell walls, including semi-crystalline cellulose, to soluble enzyme accessibility. In contrast to the enzymes currently used in industry, bacterial cellulosomes organize cellulases and other proteins in a scaffold structure, and are highly efficient in degrading cellulose. To mimic this clustered assembly of enzymes, we conjugated cellulase obtained from Trichoderma viride to polystyrene nanospheres (cellulase:NS) and tested the hydrolytic activity of this complex on cellulose substrates from purified and natural sources. Cellulase:NS and free cellulase were equally active on soluble carboxymethyl cellulose (CMC); however, the complexed enzyme displayed a higher affinity in its action on microcrystalline cellulose. Similarly, we found that the cellulase:NS complex was more efficient in degrading natural cellulose structures in the thickened walls of cultured wood cells. These results suggest that nanoparticle-bound enzymes can improve catalytic efficiency on physically intractable substrates. We discuss the potential for further enhancement of cellulose degradation by physically clustering combinations of different glycosyl hydrolase enzymes, and applications for using cellulase:NS complexes in biofuel production. PMID:22870287

Enhanced cellulose degradation using cellulase-nanosphere complexes.

Directory of Open Access Journals (Sweden)

Craig Blanchette

Full Text Available Enzyme catalyzed conversion of plant biomass to sugars is an inherently inefficient process, and one of the major factors limiting economical biofuel production. This is due to the physical barrier presented by polymers in plant cell walls, including semi-crystalline cellulose, to soluble enzyme accessibility. In contrast to the enzymes currently used in industry, bacterial cellulosomes organize cellulases and other proteins in a scaffold structure, and are highly efficient in degrading cellulose. To mimic this clustered assembly of enzymes, we conjugated cellulase obtained from Trichoderma viride to polystyrene nanospheres (cellulase:NS and tested the hydrolytic activity of this complex on cellulose substrates from purified and natural sources. Cellulase:NS and free cellulase were equally active on soluble carboxymethyl cellulose (CMC; however, the complexed enzyme displayed a higher affinity in its action on microcrystalline cellulose. Similarly, we found that the cellulase:NS complex was more efficient in degrading natural cellulose structures in the thickened walls of cultured wood cells. These results suggest that nanoparticle-bound enzymes can improve catalytic efficiency on physically intractable substrates. We discuss the potential for further enhancement of cellulose degradation by physically clustering combinations of different glycosyl hydrolase enzymes, and applications for using cellulase:NS complexes in biofuel production.

Enhanced cellulose degradation using cellulase-nanosphere complexes.

Science.gov (United States)

Blanchette, Craig; Lacayo, Catherine I; Fischer, Nicholas O; Hwang, Mona; Thelen, Michael P

2012-01-01

Enzyme catalyzed conversion of plant biomass to sugars is an inherently inefficient process, and one of the major factors limiting economical biofuel production. This is due to the physical barrier presented by polymers in plant cell walls, including semi-crystalline cellulose, to soluble enzyme accessibility. In contrast to the enzymes currently used in industry, bacterial cellulosomes organize cellulases and other proteins in a scaffold structure, and are highly efficient in degrading cellulose. To mimic this clustered assembly of enzymes, we conjugated cellulase obtained from Trichoderma viride to polystyrene nanospheres (cellulase:NS) and tested the hydrolytic activity of this complex on cellulose substrates from purified and natural sources. Cellulase:NS and free cellulase were equally active on soluble carboxymethyl cellulose (CMC); however, the complexed enzyme displayed a higher affinity in its action on microcrystalline cellulose. Similarly, we found that the cellulase:NS complex was more efficient in degrading natural cellulose structures in the thickened walls of cultured wood cells. These results suggest that nanoparticle-bound enzymes can improve catalytic efficiency on physically intractable substrates. We discuss the potential for further enhancement of cellulose degradation by physically clustering combinations of different glycosyl hydrolase enzymes, and applications for using cellulase:NS complexes in biofuel production.

A multiscale crack-bridging model of cellulose nanopaper

Science.gov (United States)

Meng, Qinghua; Li, Bo; Li, Teng; Feng, Xi-Qiao

2017-06-01

The conflict between strength and toughness is a long-standing challenge in advanced materials design. Recently, a fundamental bottom-up material design strategy has been demonstrated using cellulose nanopaper to achieve significant simultaneous increase in both strength and toughness. Fertile opportunities of such a design strategy aside, mechanistic understanding is much needed to thoroughly explore its full potential. To this end, here we establish a multiscale crack-bridging model to reveal the toughening mechanisms in cellulose nanopaper. A cohesive law is developed to characterize the interfacial properties between cellulose nanofibrils by considering their hydrogen bonding nature. In the crack-bridging zone, the hydrogen bonds between neighboring cellulose nanofibrils may break and reform at the molecular scale, rendering a superior toughness at the macroscopic scale. It is found that cellulose nanofibrils exhibit a distinct size-dependence in enhancing the fracture toughness of cellulose nanopaper. An optimal range of the length-to-radius ratio of nanofibrils is required to achieve higher fracture toughness of cellulose nanopaper. A unified law is proposed to correlate the fracture toughness of cellulose nanopaper with its microstructure and material parameters. The results obtained from this model agree well with relevant experiments. This work not only helps decipher the fundamental mechanisms underlying the remarkable mechanical properties of cellulose nanopaper but also provides a guide to design a wide range of advanced functional materials.

Cellulose-hemicellulose interaction in wood secondary cell-wall

International Nuclear Information System (INIS)

Zhang, Ning; Li, Shi; Hong, Yu; Chen, Youping; Xiong, Liming

2015-01-01

The wood cell wall features a tough and relatively rigid fiber reinforced composite structure. It acts as a pressure vessel, offering protection against mechanical stress. Cellulose microfibrils, hemicellulose and amorphous lignin are the three major components of wood. The structure of secondary cell wall could be imagined as the same as reinforced concrete, in which cellulose microfibrils acts as reinforcing steel bar and hemicellulose-lignin matrices act as the concrete. Therefore, the interface between cellulose and hemicellulose/lignin plays a significant role in determine the mechanical behavior of wood secondary cell wall. To this end, we present a molecular dynamics (MD) simulation study attempting to quantify the strength of the interface between cellulose microfibrils and hemicellulose. Since hemicellulose binds with adjacent cellulose microfibrils in various patterns, the atomistic models of hemicellulose-cellulose composites with three typical binding modes, i.e. bridge, loop and random binding modes are constructed. The effect of the shape of hemicellulose chain on the strength of hemicellulose-cellulose composites under shear loadings is investigated. The contact area as well as hydrogen bonds between cellulose and hemicellulose, together with the covalent bonds in backbone of hemicellulose chain are found to be the controlling parameters which determine the strength of the interfaces in the composite system. For the bridge binding model, the effect of shear loading direction on the strength of the cellulose material is also studied. The obtained results suggest that the shear strength of wood-inspired engineering composites can be optimized through maximizing the formations of the contributing hydrogen bonds between cellulose and hemicellulose. (paper)

Cellulose-hemicellulose interaction in wood secondary cell-wall

Science.gov (United States)

Zhang, Ning; Li, Shi; Xiong, Liming; Hong, Yu; Chen, Youping

2015-12-01

The wood cell wall features a tough and relatively rigid fiber reinforced composite structure. It acts as a pressure vessel, offering protection against mechanical stress. Cellulose microfibrils, hemicellulose and amorphous lignin are the three major components of wood. The structure of secondary cell wall could be imagined as the same as reinforced concrete, in which cellulose microfibrils acts as reinforcing steel bar and hemicellulose-lignin matrices act as the concrete. Therefore, the interface between cellulose and hemicellulose/lignin plays a significant role in determine the mechanical behavior of wood secondary cell wall. To this end, we present a molecular dynamics (MD) simulation study attempting to quantify the strength of the interface between cellulose microfibrils and hemicellulose. Since hemicellulose binds with adjacent cellulose microfibrils in various patterns, the atomistic models of hemicellulose-cellulose composites with three typical binding modes, i.e. bridge, loop and random binding modes are constructed. The effect of the shape of hemicellulose chain on the strength of hemicellulose-cellulose composites under shear loadings is investigated. The contact area as well as hydrogen bonds between cellulose and hemicellulose, together with the covalent bonds in backbone of hemicellulose chain are found to be the controlling parameters which determine the strength of the interfaces in the composite system. For the bridge binding model, the effect of shear loading direction on the strength of the cellulose material is also studied. The obtained results suggest that the shear strength of wood-inspired engineering composites can be optimized through maximizing the formations of the contributing hydrogen bonds between cellulose and hemicellulose.

Common causes of red eye presenting at an ophthalmic clinic ...

African Journals Online (AJOL)

Background: Redness of the eye is a common ophthalmic symptom. The problem causing redness could arise from within or outside the globe. These range from cases of simple inflammation following itching and minor trauma for example, to severe cases like orbital cellulitis and tumours. Patients may not even be aware of ...

Lattice insertions for POPAE

International Nuclear Information System (INIS)

Cho, Y.; Crosbie, E.A.; Diebold, R.; Johnson, D.E.; Ohnuma, S.; Ruggiero, A.G.; Teng, L.C.

1977-01-01

Four types of insertions are described for the six 200-m straight sections of POPAE. All have dispersion matched to zero. (1) Injection-ejection insertion--This has proper high-β values and phase advances for horizontal injection and vertical ejection. (2) Phase-adjust insertion--The phase advance in this insertion is adjustable over a range of approximately 100 0 . (3) General-purpose insertion--The β* is adjustable from 2.5. to 200 m and the crossing angle is adjustable from 0 to 11 mrad. (4) High-luminosity insertion--This gives an even lower β + of meter

Method of saccharifying cellulose

Science.gov (United States)

Johnson, E.A.; Demain, A.L.; Madia, A.

1983-05-13

A method is disclosed of saccharifying cellulose by incubation with the cellulase of Clostridium thermocellum in a broth containing an efficacious amount of thiol reducing agent. Other incubation parameters which may be advantageously controlled to stimulate saccharification include the concentration of alkaline earth salts, pH, temperature, and duration. By the method of the invention, even native crystalline cellulose such as that found in cotton may be completely saccharified.

Alpha autoradiography by cellulose nitrate layer

International Nuclear Information System (INIS)

Simonovic, J.; Vukovic, J.; Antanasijevic, R.

1976-01-01

From domestic cellulose nitrate bulk material thin layers for α-particle autoradiography were prepared. An artifical test specimen of a uniformly alpha labelled grid source was used. The efficiency of autoradiographs by cellulose nitrate was calculated comparing with data from an Ilford K2 nuclear emulsion exposed under the same conditions as the cellulose nitrate film. The resolution was determined as the distance from grid pitch edge at which the track density fell considerably. (orig.) [de

Efficacy of detergent and water versus bleach for disinfection of direct contact ophthalmic lenses.

Science.gov (United States)

Abbey, Ashkan M; Gregori, Ninel Z; Surapaneni, Krishna; Miller, Darlene

2014-06-01

Although manufacturers recommend cleaning ophthalmic lenses with detergent and water and then with a specific disinfectant, disinfectants are rarely used in ophthalmic practices. The aim of this pilot study was to evaluate the efficacy of detergent and water versus that of bleach, a recommended disinfectant, to eliminate common ocular bacteria and viruses from ophthalmic lenses. Three bacterial strains (Staphylococcus epidermidis, Corynebacterium straitum, and methicillin-resistant Staphylococcus aureus and 2 viral strains (adenovirus and herpes simplex virus [HSV] type-1) were individually inoculated onto 20 gonioscopy and laser lenses. The lenses were washed with detergent and water and then disinfected with 10% bleach. All the lenses were cultured after inoculation, after washing with detergent and water, and after disinfecting with the bleach. Bacterial cultures in thioglycollate broth were observed for 3 weeks, and viral cultures were observed for 2 weeks. The presence of viruses was also detected by multiplex polymerase chain reaction (PCR). All 20 lenses inoculated with S. epidermidis, C. straitum, adenovirus, and HSV-1 showed growth after inoculation but no growth after washing with detergent/water and after disinfecting with the bleach. All lenses showed positive HSV and adenovirus PCR results after inoculation and negative PCR results after washing with detergent/water and after disinfecting with bleach. All methicillin-resistant S. aureus-contaminated lenses showed growth after inoculation and no growth after washing with detergent and water. However, 1 lens showed positive growth after disinfecting with bleach. Cleaning with detergent and water seemed to effectively eliminate bacteria and viruses from the surface of contaminated ophthalmic lenses. Further studies are warranted to design practical disinfection protocols that minimize lens damage.

Facilitation of tear fluid secretion by 3% diquafosol ophthalmic solution in normal human eyes.

Science.gov (United States)

Yokoi, Norihiko; Kato, Hiroaki; Kinoshita, Shigeru

2014-01-01

To evaluate the increase in tear fluid volume induced by 3% diquafosol ophthalmic solution in normal human eyes. Prospective, randomized, double-masked, comparative study. Twenty healthy adults (17 males and 3 females; mean age, 38.8 years) underwent topical instillation of 2 ophthalmic solutions, artificial tears in 1 eye and 3% diquafosol ophthalmic solution in the fellow eye, in a masked manner. The radius of curvature of the central lower tear meniscus was measured at 5, 10, 15, 30, and 60 minutes after instillation by use of reflective meniscometry, and subjects' self-evaluated symptoms of wetness and stinging using a visual analog scale. Changes after instillation in the radius of curvature from baseline (artificial tear group vs diquafosol group; mean ± standard error of the mean) were as follows: at 5 minutes, -0.008 ± 0.012 vs 0.045 ± 0.013; at 10 minutes, 0.001 ± 0.014 vs 0.057 ± 0.016; at 15 minutes, -0.012 ± 0.014 vs 0.037 ± 0.019; at 30 minutes, -0.010 ± 0.016 vs 0.030 ± 0.025; and at 60 minutes, -0.029 ± 0.012 vs -0.020 ± 0.012. The diquafosol group showed significantly greater values from 5 to 30 minutes after instillation. Of the 40 eyes, 13 showed abnormal tear film breakup time (≤5 seconds). The diquafosol group had significantly more wetness at 15 minutes after instillation than did the artificial tear group. Topical instillation of 3% diquafosol ophthalmic solution increases tear fluid on the ocular surface for up to 30 minutes in normal human eyes. Copyright © 2014 Elsevier Inc. All rights reserved.

Relationship between the Direction of Ophthalmic Artery Blood Flow and Ocular Microcirculation before and after Carotid Artery Stenting.

Science.gov (United States)

Ishii, Masashi; Hayashi, Morito; Yagi, Fumihiko; Sato, Kenichiro; Tomita, Goji; Iwabuchi, Satoshi

2016-01-01

When internal carotid artery stenosis is accompanied by ocular ischemic syndrome, intervention is recommended to prevent irreversible visual loss. In this study, we used laser speckle flowgraphy to measure the ocular microcirculation in the optic nerve head before and after carotid artery stenting (CAS) of 40 advanced internal carotid stenosis lesions from 37 patients. The aim was to investigate the relationship between ocular microcirculation and the direction of ophthalmic artery blood flow obtained by angiography. We found that there was a significant increase in blood flow after CAS ( P = 0.003). Peak systolic velocity as an indicator of the rate of stenosis was also significantly higher in the group with retrograde/undetected flow of the ophthalmic artery than in the group with antegrade flow ( P = 0.002). In all cases where retrograde flow of the ophthalmic artery was observed before stenting, the flow changed to antegrade after stenting. Through the use of laser speckle flowgraphy, this study found that CAS can improve ocular microcirculation. Furthermore, while patients displaying retrograde flow of the ophthalmic artery before stenting have a poor prognosis, CAS corrected the flow to antegrade, suggesting that visual loss can be prevented by improving the ocular microcirculation.

Preliminary study for acetylation of cassava bagasse starch and microfibrillated cellulose of bamboo

Directory of Open Access Journals (Sweden)

Silviana Silviana

2018-01-01

Full Text Available Bio composite matrixes have been developed from several biomaterials, such as starch. One of potential resources is starch isolated from cassava bagasse still consisting 30-50% of starch. Reinforcement material may be inserted into bio composite to tough and reduce the drawback of the starch-based bio composite or bio plastic. Microfibrillated cellulose of bamboo (MFC can be used as toughening filler for composite matrix. However, surface modification of material could be employed to alter its properties, such as acetylation of starch-based bio composite and microfibrillated cellulose. The acetylation was executed by using glacial acetic acid (GAA catalyzed with sodium hydroxide. This paper investigates optimum condition of acetylation for bagasse starch (BS and bamboo MFC in different weight ratio of GAA to BS or MFC (1:1, 2:1, 3:1, 1:2, 1:3, temperature range of 30°C to 70°C, and pH range of 7 to 11. Data were resulted from degree of susbtitution for each running. The optimum condition of acetylation of BS was obtained at temperature of 50°C (for BS and 30°C (for MFC, pH of 9, and 2:1 ratio. This acetylation was confirmed by fourier transform infrared spectroscopy and scanning electron microscope.

The impact of the European Working Time Regulations on Ophthalmic Specialist Training--a national trainee survey.

Science.gov (United States)

O'Gallagher, M K; Lewis, G; Mercieca, K; Moutray, T

2013-01-01

To assess ophthalmic trainees' perspective of the impact of the European Working Time Regulations (EWTR) on their training. All trainees in ophthalmology in the UK were emailed a link to an electronic survey asking about their experiences of the EWTR. 324 trainees (46% of those invited) responded to the survey. 44.4% of trainees reported that their posts were compliant with the EWTR. 40.7% felt that training had been adversely affected. 49.1% thought that ophthalmic trainees should opt out of the EWTR to work more than 48 h per week, with 57 the mean number of hours suggested appropriate. Many ophthalmic trainees in the United Kingdom are working in rotas which are not compliant with the European Working Time Directive. Many trainees feel that implementation of the EWTD has had a negative effect on training and feel it would be acceptable to work a higher number of hours per week. Copyright © 2013 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.

Bromfenac ophthalmic solution for the treatment of postoperative ocular pain and inflammation: safety, efficacy, and patient adherence

OpenAIRE

Rajpal, Rajesh K; Ross, Bryan; Rajpal, Sachin D; Hoang, Khoa

2014-01-01

Rajesh K Rajpal, Bryan Ross, Sachin D Rajpal, Khoa HoangSee Clearly Vision Group, McLean, VA, USAAbstract: Ophthalmic nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used by clinicians to manage ocular inflammation and pain following cataract surgery. Over the past decade, the US Food and Drug Administration has approved multiple topical NSAIDs for these purposes, including several reformulated products. One of these medications, bromfenac ophthalmic solution, has a long and extens...

OPHTHALMIC FINDINGS IN LATE STAGE SJOGREN-LARSSON SYNDROME.

Science.gov (United States)

Nanda, Tavish; Kovach, Jaclyn L

2017-03-15

To report spectral domain optical coherence tomography and fundus autofluorescence documentation of late stage macular findings associated with Sjogren-Larsson Syndrome in three adult siblings. Three adult siblings with Sjogren-Larsson Syndrome underwent ophthalmic examination and imaging. Crystalline maculopathy and subretinal deposits, presumably lipofuscin accumulation, with macular atrophy were present in varying degrees in all three adult siblings. In adults with Sjogren-Larsson Syndrome, crystalline retinopathy can progress to macular atrophy and the appearance of lipofuscin accumulation.

Insertion Modeling and Its Applications

OpenAIRE

Alexander Letichevsky; Oleksandr Letychevskyi; Vladimir Peschanenko

2016-01-01

The paper relates to the theoretical and practical aspects of insertion modeling. Insertion modeling is a theory of agents and environments interaction where an environment is considered as agent with a special insertion function. The main notions of insertion modeling are presented. Insertion Modeling System is described as a tool for development of different kinds of insertion machines. The research and industrial applications of Insertion Modeling System are presented.

Cellulose-reinforced composites: from micro-to nanoscale

Directory of Open Access Journals (Sweden)

Alain Dufresne

2013-01-01

Full Text Available This paper present the most relevant advances in the fields of: i cellulose fibres surface modification; ii cellulose fibres-based composite materials; and iii nanocomposites based on cellulose whiskers or starch platelet-like nanoparticles. The real breakthroughs achieved in the first topic concern the use of solvent-free grafting process (plasma and the grafting of the matrix at the surface of cellulose fibres through isocyanate-mediated grafting or thanks to "click chemistry". Concerning the second topic, it is worth to mention that for some cellulose/matrix combination and in the presence of adequate aids or specific surface treatment, high performance composite materials could be obtained. Finally, nanocomposites allow using the semi-crystalline nature and hierarchical structure of lignocellulosic fibres and starch granules to more deeply achieve this goal profitably exploited by Mother Nature

Electrocatalytic oxidation of cellulose at a gold electrode.

Science.gov (United States)

Sugano, Yasuhito; Latonen, Rose-Marie; Akieh-Pirkanniemi, Marceline; Bobacka, Johan; Ivaska, Ari

2014-08-01

The electrochemical properties of cellulose dissolved in NaOH solution at a Au surface were investigated by cyclic voltammetry, FTIR spectroscopy, the electrochemical quartz crystal microbalance technique, and electrochemical impedance spectroscopy. The reaction products were characterized by SEM, TEM, and FTIR and NMR spectroscopy. The results imply that cellulose is irreversibly oxidized. Adsorption and desorption of hydroxide ions at the Au surface during potential cycling have an important catalytic role in the reaction (e.g., approach of cellulose to the electrode surface, electron transfer, adsorption/desorption of the reaction species at the electrode surface). Moreover, two types of cellulose derivatives were obtained as products. One is a water-soluble cellulose derivative in which some hydroxyl groups are oxidized to carboxylic groups. The other derivative is a water-insoluble hybrid material composed of cellulose and Au nanoparticles (≈4 nm). Furthermore, a reaction scheme of the electrocatalytic oxidation of cellulose at a gold electrode in a basic medium is proposed. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mass spectrometric studies of fast pyrolysis of cellulose

Energy Technology Data Exchange (ETDEWEB)

Degenstein, John; Hurt, Matt; Murria, Priya; Easton, McKay; Choudhari, Harshavardhan; Yang, Linan; Riedeman, James; Carlsen, Mark; Nash, John; Agrawal, Rakesh; Delgass, W.; Ribeiro, Fabio; Kenttämaa, Hilkka

2015-01-01

A fast pyrolysis probe/linear quadrupole ion trap mass spectrometer combination was used to study the primary fast pyrolysis products (those that first leave the hot pyrolysis surface) of cellulose, cellobiose, cellotriose, cellotetraose, cellopentaose, and cellohexaose, as well as of cellobiosan, cellotriosan, and cellopentosan, at 600°C. Similar products with different branching ratios were found for the oligosaccharides and cellulose, as reported previously. However, identical products (with the exception of two) with similar branching ratios were measured for cellotriosan (and cellopentosan) and cellulose. This result demonstrates that cellotriosan is an excellent small-molecule surrogate for studies of the fast pyrolysis of cellulose and also that most fast pyrolysis products of cellulose do not originate from the reducing end. Based on several observations, the fast pyrolysis of cellulose is suggested to initiate predominantly via two competing processes: the formation of anhydro-oligosaccharides, such as cellobiosan, cellotriosan, and cellopentosan (major route), and the elimination of glycolaldehyde (or isomeric) units from the reducing end of oligosaccharides formed from cellulose during fast pyrolysis.

Efficacy of Detergent and Water Versus Bleach for the Disinfection of Direct Contact Ophthalmic Lenses

Science.gov (United States)

Abbey, Ashkan M.; Gregori, Ninel Z.; Surapaneni, Krishna; Miller, Darlene

2014-01-01

Purpose While manufacturers recommend cleaning ophthalmic lenses with detergent and water and then a specific disinfectant, disinfectants are rarely used in ophthalmic practices. The aim of this pilot study was to evaluate the efficacy of detergent and water versus bleach, a recommended disinfectant, to eliminate common ocular bacteria and viruses from ophthalmic lenses. Methods Three bacterial strains (Staphylococcus epidermidis, Corynebacterium straitum, and methicillin-resistant Staphylococcus aureus (MRSA) and two viral strains (adenovirus and herpes simplex virus (HSV) type-1) were individually inoculated to 20 gonioscopy and laser lenses. Lenses were washed with detergent and water and then disinfected with 10% bleach. All lenses were cultured after inoculation, after detergent and water, and after the bleach. Bacterial cultures in thioglycollate broth were observed for 3 weeks and viral cultures for 2 weeks. The presence of viruses was also detected by multiplex polymerase chain reaction (PCR). Results All 20 lenses inoculated with Staphylococcus epidermidis, Corynebacterium straitum, adenovirus, and HSV-1 showed growth after inoculation, but no growth after detergent/water and after the bleach. All lenses showed positive HSV and adenovirus PCR after inoculation and negative PCR after detergent/water and after bleach. All MRSA contaminated lenses showed growth after inoculation and no growth after detergent and water. However, one lens showed positive growth after bleach. Conclusions Cleaning with detergent and water appeared to effectively eliminate bacteria and viruses from the surface of contaminated ophthalmic lenses. Further studies are warranted to design practical disinfection protocols that minimize lens damage. PMID:24747806

Design of Novel Ophthalmic Formulation Containing Drug Nanoparticles and Its Usefulness as Anti-glaucoma Drugs.

Science.gov (United States)

Nagai, Noriaki

2016-01-01

The ophthalmic application of drugs is the primary route of administration for the therapy of glaucoma; however, in traditional formulations, only small amounts of the administered drug penetrate the cornea to reach the desired intraocular tissue due to corneal barriers. Recently, nanoparticulate drug delivery is expected as a technology to overcome the difficulties in delivering drugs across biological barriers (improvement of bioavailability). In this study, we attempted to establish a new method for preparing solid drug nanoparticles by using a bead mill and various additives, and succeeded in preparing a high quality dispersion containing drug nanoparticles. For a more concrete example, a mean particle size of disulfiram (DSF) treated with bead mill is 183 nm. The corneal penetration and corneal residence time of DSF from the ophthalmic dispersion containing DSF nanoparticles were significantly higher than those from a 2-hydroxypropyl-β-cyclodextrin solution containing DSF (DSF solution). It is known that the administration of DSF has intraocular pressure (IOP)-reducing effects. The IOP-reducing effects of the ophthalmic dispersion containing DSF nanoparticles were significantly greater than those of the DSF solution in rabbits (the IOP was enhanced by placing the rabbits in a dark room for 5 h). In addition, the ophthalmic dispersion containing DSF nanoparticles is better tolerated by corneal epithelial cells than DSF solution. It is possible that dispersions containing DSF nanoparticles provide new possibilities for effectively treating glaucoma, and that ocular drug delivery systems using drug nanoparticles may expand their usage for therapy in the ophthalmologic field.

Enzymatic Cellulose Palmitate Synthesis Using Immobilized Lipase

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Anna Roosdiana

2017-06-01

Full Text Available Bacterial cellulose can be modified by esterification using palmitic acid and Mucor miehei  lipase  as catalyst. The purpose of this research was to determine the optimum conditions of esterification reaction of cellulose and palmitic acid . The esterification reaction was carried out at the time variation  of  6, 12, 18, 24 and 30 hours and the mass ratio of cellulose: palmitic acid (1: 11: 2, 1: 3, 1: 4, 1: 5,1:6 at 50 °C. The   cellulose palmitate  was examined  its  physical and chemical properties by using FTIR spectrophotometer, XRD, bubble point test and saponification  apparatus. The results showed that the optimum reaction time of esterification reaction of cellulose and palmitic acid occurred within 24 hours and the mass ratio of cellulose: palmitic acid was 1: 3 resulting in DS of  0.376 with  swelling index of 187 %, crystallinity index of 61.95%,  and Φ porous of 2.40 μm. Identification of functional groups using FTIR spectrophotometer showed that C=O ester group  was observed at 1737.74 cm-1 and strengthened  by  the appearance of C-O ester peak at 1280 cm-1. The conclusion of this study is reaction time and reactant ratio influence significantly the DS of cellulose ester.

Microfibrillated cellulose and new nanocomposite materials: a review

DEFF Research Database (Denmark)

Siró, Istvan; Plackett, David

2010-01-01

Due to their abundance, high strength and stiffness, low weight and biodegradability, nano-scale cellulose fiber materials (e.g., microfibrillated cellulose and bacterial cellulose) serve as promising candidates for bio-nanocomposite production. Such new high-value materials are the subject...... in order to address this hurdle. This review summarizes progress in nanocellulose preparation with a particular focus on microfibrillated cellulose and also discusses recent developments in bio-nanocomposite fabrication based on nanocellulose....

Paper Actuators Made with Cellulose and Hybrid Materials

OpenAIRE

Kim, Jaehwan; Yun, Sungryul; Mahadeva, Suresha K.; Yun, Kiju; Yang, Sang Yeol; Maniruzzaman, Mohammad

2010-01-01

Recently, cellulose has been re-discovered as a smart material that can be used as sensor and actuator materials, which is termed electro-active paper (EAPap). This paper reports recent advances in paper actuators made with cellulose and hybrid materials such as multi-walled carbon nanotubes, conducting polymers and ionic liquids. Two distinct actuator principles in EAPap actuators are demonstrated: piezoelectric effect and ion migration effect in cellulose. Piezoelectricity of cellulose EAPa...

COMPARATIVE STUDY OF EARLY POSTPARTUM IUCD INSERTION TO INTERVAL IUCD INSERTION

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Shibani Devi

2016-07-01

Full Text Available INTRODUCTION According to National Family Health Survey-3, Indian women have 13% unmet need for contraception and according to District Level Household & Facility Survey-3, it is 21.3% in the postpartum period. Postpartum intrauterine contraceptive device insertion - both immediately post-placental delivery and somewhat later, but within 48 hours after delivery are options which merit consideration as the woman is likely to have a high motivation for accepting contraception and the healthcare centre provides a convenient setting for insertion of IUCD. AIM Comparison of efficacy and complications of IUCD insertions in post-placental with interval period: 6-month followup. METHOD This perspective study was conducted among 100 women: - 50 women had IUCD inserted within 10 minutes of placental delivery and 50 had insertion more than 6 weeks after delivery. They were followed till 6 months post insertion and were compared regarding early and late complications, continuation rates and expulsion rates. RESULT At the end of six months, we found higher occurrence of lower abdominal pain, heavy menstrual bleeding in case of interval insertion as compared to post-placental insertion which was statistically significant (p value-0.04 & 0.007 respectively. However, the expulsion rates of post-placental IUCD were somewhat elevated (14% compared to interval insertions (2%. Continuation rates at the end of 6 months in both the groups were 82% and 86% respectively which is comparable. CONCLUSION Post-placental IUCD is thus found to be an ideal method to meet the unmet need of postpartum women as it is easily accessible and convenient for both women and their health care providers, is associated with less discomfort and fewer side effects and allow women to obtain safe, long acting, highly effective contraception while still in the health care system.

Method of producing thin cellulose nitrate film

International Nuclear Information System (INIS)

Lupica, S.B.

1975-01-01

An improved method for forming a thin nitrocellulose film of reproducible thickness is described. The film is a cellulose nitrate film, 10 to 20 microns in thickness, cast from a solution of cellulose nitrate in tetrahydrofuran, said solution containing from 7 to 15 percent, by weight, of dioctyl phthalate, said cellulose nitrate having a nitrogen content of from 10 to 13 percent

Tritium transfer studies in cellulose-HTO system

International Nuclear Information System (INIS)

Jayaraman, A.P.; Misra, B.M.

1986-01-01

This paper describes some aspects of studies on transfer of tritium to cellulose from tritiated water at six different specific activities and discusses the generalized tritiation pattern. Cellulose was irradiated in steps to 10 M Rads and the tritium transfer was determined at each stage. Experimental results signify substantial increase of tritiation in cellulose at higher dose of irradiation. (author). 8 refs

Characterization of low crystallinity cellulose as a direct compression excipient: Effects of physicochemical properties of cellulose excipients on their tabletting characteristics

Science.gov (United States)

Kothari, Sanjeev Hukmichand

A scale-up method for the preparation of a new excipient, low crystallinity powder cellulose (LCPC), was established. Physicochemical characterization of a series of LCPC materials was performed, and compared to the physicochemical properties of commercially existing cellulose excipients, microcrystalline cellulose (AvicelsRTM) and powdered celluloses (Solka Flocs RTM). Low crystallinity cellulose powders had high amorphous contents (>50%) and a low degree of polymerization (2 kg), typically showed low yield pressures (200 MPa), and intermediate compactability (250--600 MPa2) values. Mechanical characterization of the three types of cellulose materials, and the statistical models obtained for the results, indicated that a high porosity (>810%), a high average of amorphous content (>40%) and moisture content (>4%), and a low degree of polymerization (disintegration times (5 to 90 seconds) for LCPC tablets at low as well as high solid fractions suggest the high affinity of these materials to water, due to their high amorphous contents that expose a larger number of hydroxyl groups to water, compared to the more crystalline materials, such as microcrystalline celluloses, the tablets of which showed extremely long disintegration times (24 to 6000 seconds). The physicochemical and mechanical characterization of low crystallinity cellulose suggests it to be a promising direct compression excipient for immediate release tablet formulations.

Isolation of cellulose fibers from kenaf using electron beam

International Nuclear Information System (INIS)

Shin, Hye Kyoung; Pyo Jeun, Joon; Bin Kim, Hyun; Hyun Kang, Phil

2012-01-01

Cellulose fibers were isolated from a kenaf bast fiber using a electron beam irradiation (EBI) treatment. The methods of isolation were based on a hot water treatment after EBI and two-step bleaching processes. FT-IR spectroscopy demonstrated that the content of lignin and hemicellulose in the bleached cellulose fibers treated with various EBI doses decreased with increasing doses of EBI. Specifically, the lignin in the bleached cellulose fibers treated at 300 kGy, was almost completely removed. Moreover, XRD analyses showed that the bleached cellulose fibers treated at 300 kGy presented the highest crystallinity of all the samples treated with EBI. Finally, the morphology of the bleached fiber was characterized by SEM imagery, and the studies showed that the separated degree of bleached cellulose fibers treated with various EBI doses increased with an increase of EBI dose, and the bleached cellulose fibers obtained by EBI treatment at 300 kGy was separated more uniformly than the bleached cellulose fiber obtained by alkali cooking with non-irradiated kenaf fiber. - Highlights: ► This study was to provide a progressive and convenient cellulose isolation process. ► Using an electron beam irradiation, we can obtain cellulose fibers using only water without chemicals during cooking process. ► We think that this cellulose isolation method will have an effect on enormous environmental and economic benefits.

Extraction of cellulose microcrystalline from galam wood for biopolymer

Science.gov (United States)

Ismail, Ika; Sa'adiyah, Devy; Rahajeng, Putri; Suprayitno, Abdi; Andiana, Rocky

2018-04-01

Consumption of plastic raw materials tends to increase, but until now the meet of the consumption of plastic raw are still low, even some are still imported. Nowadays, Indonesia's plastic needs are supported by petrochemicals where raw materials are still dependent abroad and petropolymer raw materials are derived from petroleum which will soon be depleted due to rising petroleum needs. Therefore, various studies have been conducted to develop natural fiber-based polymers that are biodegradable and abundant in nature. It is because the natural polymer production process is very efficient and very environmentally friendly. There have been many studies of biopolymers especially natural fiber-based polymers from plants, due to plants containing cellulose, hemicellulose and lignin. However, cellulose is the only one who has crystalline structures. Cellulose has a high crystality compared to amorphous lignin and hemicellulose. In this study, extracted cellulose as biopolymer and amplifier on composite. The cellulose is extracted from galam wood from East Kalimantan. Cellulose extraction will be obtained in nano / micro form through chemical and mechanical treatment processes. The chemical treatment of cellulose extraction is alkalinization process using NaOH solution, bleaching using NaClO2 and acid hydrolysis using sulfuric acid. After chemical treatment, ultrasonic mechanical treatment is made to make cellulose fibers into micro or nano size. Besides, cellulose results will be characterized. Characterization was performed to analyze molecules of cellulose compounds extracted from plants using Fourier Transformation Infra Red (FTIR) testing. XRD testing to analyze cellulose crystallinity. Scanning Electron Microscope (SEM) test to analyze morphology and fiber size.

A novel nanoparticles impregnated ocular insert for enhanced bioavailability to posterior segment of eye: In vitro, in vivo and stability studies

Energy Technology Data Exchange (ETDEWEB)

Rathod, Lalaji V.; Kapadia, Rakhee; Sawant, Krutika K., E-mail: dr_krutikasawant@rediffmail.com

2017-02-01

neither affected the intra ocular pressure establishing their safety and non irritancy. - Highlights: • The present investigation reports a novel nanoparticle impregnated ocular inserts. • It demonstrates a novel method to enhance retention time of drug in eye. • It explores use of nanoparticle impregnated ocular inserts for treatment of eye diseases. • This investigation reports a novel formulation for ophthalmic drug delivery.

A novel nanoparticles impregnated ocular insert for enhanced bioavailability to posterior segment of eye: In vitro, in vivo and stability studies

International Nuclear Information System (INIS)

Rathod, Lalaji V.; Kapadia, Rakhee; Sawant, Krutika K.

2017-01-01

ocular pressure establishing their safety and non irritancy. - Highlights: • The present investigation reports a novel nanoparticle impregnated ocular inserts. • It demonstrates a novel method to enhance retention time of drug in eye. • It explores use of nanoparticle impregnated ocular inserts for treatment of eye diseases. • This investigation reports a novel formulation for ophthalmic drug delivery.

Deep lateral wall orbital decompression following strabismus surgery in patients with Type II ophthalmic Graves' disease.

Science.gov (United States)

Ellis, Michael P; Broxterman, Emily C; Hromas, Alan R; Whittaker, Thomas J; Sokol, Jason A

2018-01-10

Surgical management of ophthalmic Graves' disease traditionally involves, in order, orbital decompression, followed by strabismus surgery and eyelid surgery. Nunery et al. previously described two distinct sub-types of patients with ophthalmic Graves' disease; Type I patients exhibit no restrictive myopathy (no diplopia) as opposed to Type II patients who do exhibit restrictive myopathy (diplopia) and are far more likely to develop new-onset worsening diplopia following medial wall and floor decompression. Strabismus surgery involving extra-ocular muscle recession has, in turn, been shown to potentially worsen proptosis. Our experience with Type II patients who have already undergone medial wall and floor decompression and strabismus surgery found, when additional decompression is necessary, deep lateral wall decompression (DLWD) appears to have a low rate of post-operative primary-gaze diplopia. A case series of four Type II ophthalmic Graves' disease patients, all of whom had already undergone decompression and strabismus surgery, and went on to develop worsening proptosis or optic nerve compression necessitating further decompression thereafter. In all cases, patients were treated with DLWD. Institutional Review Board approval was granted by the University of Kansas. None of the four patients treated with this approach developed recurrent primary-gaze diplopia or required strabismus surgery following DLWD. While we still prefer to perform medial wall and floor decompression as the initial treatment for ophthalmic Graves' disease, for proptosis following consecutive strabismus surgery, DLWD appears to be effective with a low rate of recurrent primary-gaze diplopia.

A xylanase-aided enzymatic pretreatment facilitates cellulose nanofibrillation.

Science.gov (United States)

Long, Lingfeng; Tian, Dong; Hu, Jinguang; Wang, Fei; Saddler, Jack

2017-11-01

Although biological pretreatment of cellulosic fiber based on endoglucanases has shown some promise to facilitate cellulose nanofibrillation, its efficacy is still limited. In this study, a xylanase-aided endoglucanase pretreatment was assessed on the bleached hardwood and softwood Kraft pulps to facilitate the downstream cellulose nanofibrillation. Four commercial xylanase preparations were compared and the changes of major fiber physicochemical characteristics such as cellulose/hemicellulose content, gross fiber properties, fiber morphologies, cellulose accessibility/degree of polymerization (DP)/crystallinity were systematically evaluated before and after enzymatic pretreatment. It showed that the synergistic cooperation between endoglucanase and certain xylanase (Biobrite) could efficiently "open up" the hardwood Kraft pulp with limited carbohydrates degradation (cellulose nanofibrillation during mild sonication process (90Wh) with more uniform disintegrated nanofibril products (50-150nm, as assessed by scanning electron microscopy and UV-vis spectroscopy). Copyright © 2017 Elsevier Ltd. All rights reserved.

Crystallographic snapshot of cellulose synthesis and membrane translocation.

Science.gov (United States)

Morgan, Jacob L W; Strumillo, Joanna; Zimmer, Jochen

2013-01-10

Cellulose, the most abundant biological macromolecule, is an extracellular, linear polymer of glucose molecules. It represents an essential component of plant cell walls but is also found in algae and bacteria. In bacteria, cellulose production frequently correlates with the formation of biofilms, a sessile, multicellular growth form. Cellulose synthesis and transport across the inner bacterial membrane is mediated by a complex of the membrane-integrated catalytic BcsA subunit and the membrane-anchored, periplasmic BcsB protein. Here we present the crystal structure of a complex of BcsA and BcsB from Rhodobacter sphaeroides containing a translocating polysaccharide. The structure of the BcsA-BcsB translocation intermediate reveals the architecture of the cellulose synthase, demonstrates how BcsA forms a cellulose-conducting channel, and suggests a model for the coupling of cellulose synthesis and translocation in which the nascent polysaccharide is extended by one glucose molecule at a time.

Biofunctional Paper via Covalent Modification of Cellulose

Science.gov (United States)

Yu, Arthur; Shang, Jing; Cheng, Fang; Paik, Bradford A.; Kaplan, Justin M.; Andrade, Rodrigo B.; Ratner, Daniel M.

2012-01-01

Paper-based analytical devices are the subject of growing interest for the development of low-cost point-of-care diagnostics, environmental monitoring technologies and research tools for limited-resource settings. However, there are limited chemistries available for the conjugation of biomolecules to cellulose for use in biomedical applications. Herein, divinyl sulfone (DVS) chemistry was demonstrated to covalently immobilize small molecules, proteins and DNA onto the hydroxyl groups of cellulose membranes through nucleophilic addition. Assays on modified cellulose using protein-carbohydrate and protein-glycoprotein interactions as well as oligonucleotide hybridization showed that the membrane’s bioactivity was specific, dose-dependent, and stable over a long period of time. Use of an inkjet printer to form patterns of biomolecules on DVS-activated cellulose illustrates the adaptability of the DVS functionalization technique to pattern sophisticated designs, with potential applications in cellulose-based lateral flow devices. PMID:22708701

Development of composites of polycaprolactone with cellulose

International Nuclear Information System (INIS)

Aguiar, V.O.; Marques, M.F.V.

2015-01-01

In the present work, alkaline followed by an acid treatment were performed in plant sources of curaua and jute fibers to remove the amorphous portion and to aid fibrillation. Using the technique of X-ray diffraction it was observed that the chemical treatments led to a better organization of cellulose microfibrils and, consequently, the increase in their crystallinity index. Using the thermogravimetric analysis it was noted a slight decrease in thermal stability of the chemically treated cellulose fibers, however it did not impairs its use as filler in the polymer matrix. Through the SEM micrographs it was observed that the chemical treatment reduced the dimensions of the fibers in natura. Polycaprolactone composite was prepared in a twin-screw extruder at different amounts for several cellulose sources (those obtained from vegetable fibers, curaua and jute, commercial cellulose and amorphous cellulose) at and maintaining the process time and temperature constant. (author)

Comparison between Cellulose Nanocrystal and Cellulose Nanofibril Reinforced Poly(ethylene oxide) Nanofibers and Their Novel Shish-Kebab-Like Crystalline Structures

Science.gov (United States)

Xuezhu Xu; Haoran Wang; Long Jiang; Xinnan Wang; Scott A. Payne; J.Y. Zhu; Ruipeng Li

2014-01-01

Poly(ethylene oxide) (PEO) nanofiber mats were produced by electrospinning. Biobased cellulose nanocrystals (CNCs) and cellulose nanofibrils (CNFs) as reinforcement nanofillers were also added to the polymer to produce composite nanofiber mats. The effects of the two cellulose nanofillers on the rheological properties of the PEO solutions and the microstructure,...

Morphology and physical-chemical properties of celluloses obtained by different methods

Science.gov (United States)

Anpilova, A. Yu.; Mastalygina, E. E.; Mikhaylov, I. A.; Popov, A. A.; Kartasheva, Z. S.

2017-12-01

The morphology and structural characteristics of celluloses obtained by different methods were studied. The objects of the investigation are cellulose from pulp source, commercial celluloses produced by sodium and acid hydrolysis, laboratory produced cellulose from bleached birch kraft pulp, and cellulose obtained by thermooxidative catalytic treatment of maple leaves by peroxide. According to a complex analysis of cellulose characteristics, several types of celluloses were offered as modifying additives for polymers.

Evolving Microbial Communities in Cellulose-Fed Microbial Fuel Cell

Directory of Open Access Journals (Sweden)

Renata Toczyłowska-Mamińska

2018-01-01

Full Text Available The abundance of cellulosic wastes make them attractive source of energy for producing electricity in microbial fuel cells (MFCs. However, electricity production from cellulose requires obligate anaerobes that can degrade cellulose and transfer electrons to the electrode (exoelectrogens, and thus most previous MFC studies have been conducted using two-chamber systems to avoid oxygen contamination of the anode. Single-chamber, air-cathode MFCs typically produce higher power densities than aqueous catholyte MFCs and avoid energy input for the cathodic reaction. To better understand the bacterial communities that evolve in single-chamber air-cathode MFCs fed cellulose, we examined the changes in the bacterial consortium in an MFC fed cellulose over time. The most predominant bacteria shown to be capable electron generation was Firmicutes, with the fermenters decomposing cellulose Bacteroidetes. The main genera developed after extended operation of the cellulose-fed MFC were cellulolytic strains, fermenters and electrogens that included: Parabacteroides, Proteiniphilum, Catonella and Clostridium. These results demonstrate that different communities evolve in air-cathode MFCs fed cellulose than the previous two-chamber reactors.

Cellulose nanocrystals from acacia bark-Influence of solvent extraction.

Science.gov (United States)

Taflick, Ticiane; Schwendler, Luana A; Rosa, Simone M L; Bica, Clara I D; Nachtigall, Sônia M B

2017-08-01

The isolation of cellulose nanocrystals from different lignocellulosic materials has shown increased interest in academic and technological research. These materials have excellent mechanical properties and can be used as nanofillers for polymer composites as well as transparent films for various applications. In this work, cellulose isolation was performed following an environmental friendly procedure without chlorine. Cellulose nanocrystals were isolated from the exhausted acacia bark (after the industrial process of extracting tannin) with the objective of evaluating the effect of the solvent extraction steps on the characteristics of cellulose and cellulose nanocrystals. It was also assessed the effect of acid hydrolysis time on the thermal stability, morphology and size of the nanocrystals, through TGA, TEM and light scattering analyses. It was concluded that the extraction step with solvents was important in the isolation of cellulose, but irrelevant in the isolation of cellulose nanocrystals. Light scattering experiments indicated that 30min of hydrolysis was long enough for the isolation of cellulose nanocrystals. Copyright © 2017 Elsevier B.V. All rights reserved.

Characterization of TEMPO-oxidized bacterial cellulose

International Nuclear Information System (INIS)

Nascimento, Eligenes S.; Pereira, Andre L.S.; Lima, Helder L.; Barroso, Maria K. de A.; Barros, Matheus de O.; Morais, Joao P.S.; Borges, Maria de F.; Rosa, Morsyleide de F.

2015-01-01

The aim of this study was to characterize the TEMPO-oxidized bacterial cellulose, as a preliminary research for further application in nanocomposites. Bacterial cellulose (BC) was selectively oxidized at C-6 carbon by TEMPO radical. Oxidized bacterial cellulose (BCOX) was characterized by TGA, FTIR, XRD, and zeta potential. BCOX suspension was stable at pH 7.0, presented a crystallinity index of 83%, in spite of 92% of BC, because of decrease in the free hydroxyl number. FTIR spectra showed characteristic BC bands and, in addition, band of carboxylic group, proving the oxidation. BCOX DTG showed, in addition to characteristic BC thermal events, a maximum degradation peak at 233 °C, related to sodium anhydro-glucuronate groups formed during the cellulose oxidation. Thus, BC can be TEMPO-oxidized without great loss in its structure and properties. (author)

Digital video recording and archiving in ophthalmic surgery

Directory of Open Access Journals (Sweden)

Raju Biju

2006-01-01

Full Text Available Currently most ophthalmic operating rooms are equipped with an analog video recording system [analog Charge Couple Device camera for video grabbing and a Video Cassette Recorder for recording]. We discuss the various advantages of a digital video capture device, its archiving capabilities and our experience during the transition from analog to digital video recording and archiving. The basic terminology and concepts related to analog and digital video, along with the choice of hardware, software and formats for archiving are discussed.

Evaluation of supercritical CO2 dried cellulose aerogels as nano-biomaterials

Science.gov (United States)

Lee, Sinah; Kang, Kyu-Young; Jeong, Myung-Joon; Potthast, Antje; Liebner, Falk

2017-10-01

Cellulose is the renewable, biodegradable and abundant resource and is suggested as an alternative material to silica due to the high price and environmental load of silica. The first step for cellulose aerogel production is to dissolve cellulose, and hydrated calcium thiocyanate molten salt is one of the most effective solvents for preparing porous material. Cellulose aerogels were prepared from dissolved cellulose samples of different degree of polymerization (DP) and drying methods, and tested with shrinkage, density and mechanical strength. Supercritical CO2 dried cellulose aerogels shrank less compared to freeze-dried cellulose aerogels, whereas the densities were increased according to the DP increases in both cellulose aerogels. Furthermore, scanning electron microscope (SEM) images showed that the higher DP cellulose aerogels were more uniform with micro-porous structure. Regarding the mechanical strength of cellulose aerogels, supercritical CO2 dried cellulose aerogels with higher molecular weight were much more solid.

10 CFR 35.491 - Training for ophthalmic use of strontium-90.

Science.gov (United States)

2010-01-01

... the requirements in paragraph (b) of this section and has achieved a level of competency sufficient to... require the authorized user of strontium-90 for ophthalmic radiotherapy to be a physician who— (a) Is an...; (iii) Mathematics pertaining to the use and measurement of radioactivity; and (iv) Radiation biology...

Influence of Ophthalmic Solutions on Tear Components.

Science.gov (United States)

Shigeyasu, Chika; Yamada, Masakazu; Akune, Yoko

2016-11-01

Tear fluids are a mixture of secretions derived from lacrimal glands, accessory lacrimal glands, conjunctiva, and meibomian glands. Compositional changes to tears occur in the normal state and during ocular surface disease, such as dry eye conditions. We have investigated compositional changes to tears after topical application of ophthalmic solutions, with regard to tear-specific proteins (secretory immunoglobulin A, lactoferrin, lipocalin-1, and lysozyme) and ocular surface mucin in normal and dry eye conditions using high-performance liquid chromatography. After application of saline solution (0.9% sodium chloride) in normal subjects, transient but significant decreases in all tear components were observed. The recovery of protein concentrations took up to 30 minutes and lasted longer when the saline solution was applied more frequently. When applying ophthalmic solutions, a balance between washout and dilutional effects should be considered in addition to the therapeutic effect. Investigation of the effect of diquafosol solution (3%) in normal subjects revealed a significant increase in sialic acid concentration, a marker of ocular mucin, at 5 minutes after application, whereas a significant decrease was observed with saline. This result indicates the accelerated secretion of mucin from ocular tissues induced by diquafosol. A clinical study to determine the efficacy of diquafosol in patients with dry eye revealed improvements in tear breakup time, keratoconjunctival staining scores, and Schirmer test score, accompanied by an increase in sialic acid concentration in tears. Investigating normal and dry eye conditions through tear analysis may clarify the pathophysiology of dry eye conditions and support the efficacy of treatments.

Cellulose nanocrystal submonolayers by spin coating

NARCIS (Netherlands)

Kontturi, E.J.; Johansson, L.S.; Kontturi, K.S.; Ahonen, P.; Thune, P.C.; Laine, J.

2007-01-01

Dilute concentrations of cellulose nanocrystal solutions were spin coated onto different substrates to investigate the effect of the substrate on the nanocrystal submonolayers. Three substrates were probed: silica, titania, and amorphous cellulose. According to atomic force microscopy (AFM) images,

Ophthalmic Artery Embolization as Pretreatment of Orbital Exenteration for Conjunctival Squamous Cell Carcinoma

International Nuclear Information System (INIS)

Matsuo, Toshihiko; Ohara, Nobuya; Namba, Yuzaburo; Koshima, Isao; Ida, Kentaro; Kanazawa, Susumu

2009-01-01

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.

Assessing nano cellulose developments using science and technology indicators

International Nuclear Information System (INIS)

Milanez, Douglas Henrique; Amaral, Roniberto Morato do; Faria, Leandro Innocentini Lopes de; Gregolin, Jose Angelo Rodrigues

2013-01-01

This research aims to examine scientific and technological trends of developments in nano cellulose based on scientometric and patent indicators obtained from the Science Citation Index and Derwent Innovations Index in 2001-2010. The overall nano cellulose activity indicators were compared to nanotechnology and other selected nano materials. Scientific and technological future developments in nano cellulose were forecasted using extrapolation growth curves and the main countries were also mapped. The results showed that nano cellulose publications and patent documents have increased rapidly over the last five years with an average growth rate higher than that of nanotechnology and fullerene. The USA, Japan, France, Sweden and Finland all played a significant role in nano cellulose development and the extrapolation growth curves suggested that nano cellulose scientific and technological activities are still emerging. Finally, the evidence from this study recommends monitoring nano cellulose S and T advances in the coming years. (author)

Assessing nano cellulose developments using science and technology indicators

Energy Technology Data Exchange (ETDEWEB)

Milanez, Douglas Henrique; Amaral, Roniberto Morato do; Faria, Leandro Innocentini Lopes de; Gregolin, Jose Angelo Rodrigues, E-mail: douglasmilanez@yahoo.com.br [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Nucleo de Informacao Tecnologica em Materiais. Dept. de Engenharia de Materiais

2013-11-01

This research aims to examine scientific and technological trends of developments in nano cellulose based on scientometric and patent indicators obtained from the Science Citation Index and Derwent Innovations Index in 2001-2010. The overall nano cellulose activity indicators were compared to nanotechnology and other selected nano materials. Scientific and technological future developments in nano cellulose were forecasted using extrapolation growth curves and the main countries were also mapped. The results showed that nano cellulose publications and patent documents have increased rapidly over the last five years with an average growth rate higher than that of nanotechnology and fullerene. The USA, Japan, France, Sweden and Finland all played a significant role in nano cellulose development and the extrapolation growth curves suggested that nano cellulose scientific and technological activities are still emerging. Finally, the evidence from this study recommends monitoring nano cellulose S and T advances in the coming years. (author)

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)

Enhanced hydrolysis of cellulose hydrogels by morphological modification.

Science.gov (United States)

Alfassi, Gilad; Rein, Dmitry M; Cohen, Yachin

2017-11-01

Cellulose is one of the most abundant bio-renewable materials on earth, yet the potential of cellulosic bio-fuels is not fully exploited, primarily due to the high costs of conversion. Hydrogel particles of regenerated cellulose constitute a useful substrate for enzymatic hydrolysis, due to their porous and amorphous structure. This article describes the influence of several structural aspects of the cellulose hydrogel on its hydrolysis. The hydrogel density was shown to be directly proportional to the cellulose concentration in the initial solution, thus affecting its hydrolysis rate. Using high-resolution scanning electron microscopy, we show that the hydrogel particles in aqueous suspension exhibit a dense external surface layer and a more porous internal network. Elimination of the external surface layer accelerated the hydrolysis rate by up to sixfold and rendered the process nearly independent of cellulose concentration. These findings may be of practical relevance to saccharification processing costs, by reducing required solvent quantities and enzyme load.

Enzymatic hydrolysis of biomimetic bacterial cellulose-hemicellulose composites.

Science.gov (United States)

Penttilä, Paavo A; Imai, Tomoya; Hemming, Jarl; Willför, Stefan; Sugiyama, Junji

2018-06-15

The production of biofuels and other chemicals from lignocellulosic biomass is limited by the inefficiency of enzymatic hydrolysis. Here a biomimetic composite material consisting of bacterial cellulose and wood-based hemicelluloses was used to study the effects of hemicelluloses on the enzymatic hydrolysis with a commercial cellulase mixture. Bacterial cellulose synthesized in the presence of hemicelluloses, especially xylan, was found to be more susceptible to enzymatic hydrolysis than hemicellulose-free bacterial cellulose. The reason for the easier hydrolysis could be related to the nanoscale structure of the substrate, particularly the packing of cellulose microfibrils into ribbons or bundles. In addition, small-angle X-ray scattering was used to show that the average nanoscale morphology of bacterial cellulose remained unchanged during the enzymatic hydrolysis. The reported easier enzymatic hydrolysis of bacterial cellulose produced in the presence of wood-based xylan offers new insights to overcome biomass recalcitrance through genetic engineering. Copyright © 2018 Elsevier Ltd. All rights reserved.

Bioavailability and biochemical effects of diclofenac sodium 0.1% ophthalmic solution in the domestic chicken (Gallus gallus domesticus).

Science.gov (United States)

Griggs, Angela N; Yaw, Taylor J; Haynes, Joseph S; Ben-Shlomo, Gil; Tofflemire, Kyle L; Allbaugh, Rachel A

2017-03-01

To determine if topical ophthalmic diclofenac sodium 0.1% solution alters renal parameters in the domestic chicken, and to determine if the drug is detectable in plasma after topical ophthalmic administration. Thirty healthy domestic chickens. Over 7 days, six birds were treated unilaterally with one drop of artificial tear solution (group 1), 12 birds were treated unilaterally (group 2) and 12 bilaterally (group 3) with diclofenac sodium 0.1% ophthalmic solution. Treatments were provided every 12 h in all groups. Pre- and post-treatment plasma samples from all birds were evaluated for changes in albumin, total protein, and uric acid. Post-treatment samples of all birds, collected 15 min post-administration, were analyzed by high-performance liquid chromatography with mass spectrometry for diclofenac sodium detection. A randomly selected renal sample from each group was submitted for histopathologic review. Changes in pre- and post-treatment plasma albumin were significant (P Ophthalmic diclofenac sodium 0.1% administered topically every 12 h in one or both eyes for 7 days is detectable in systemic circulation in the domestic chicken, but does not cause overt significant changes in plasma uric acid or total protein. © 2016 American College of Veterinary Ophthalmologists.

Effects of Crystal Orientation on Cellulose Nanocrystals−Cellulose Acetate Nanocomposite Fibers Prepared by Dry Spinning

Science.gov (United States)

Si Chen; Greg Schueneman; R. Byron Pipes; Jeffrey Youngblood; Robert J. Moon

2014-01-01

This work presents the development of dry spun cellulose acetate (CA) fibers using cellulose nanocrystals (CNCs) as reinforcements. Increasing amounts of CNCs were dispersed into CA fibers in efforts to improve the tensile strength and elastic modulus of the fiber. A systematic characterization of dispersion of CNCs in the polymer fiber and their effect on the...

Safety comparison of additives in antiglaucoma prostaglandin (PG analog ophthalmic formulations

Directory of Open Access Journals (Sweden)

Fukuda M

2013-03-01

Full Text Available Masamichi Fukuda, Shinsuke Shibata, Naoko Shibata, Kenta Hagihara, Hiromoto Yaguchi, Hiromi Osada, Nobuo Takahashi, Eri Kubo, Hiroshi SasakiDepartment of Ophthalmology, Kanazawa Medical University, Uchinada, JapanPurpose: To investigate the safety of five types of antiglaucoma prostaglandin analog ophthalmic formulations, and to clarify their differences in accordance with contained additives (preservatives and surface-active agents.Methods: The following five types of ophthalmic solutions and three types of additives were investigated: latanoprost (Xalatan®; latanoprost, tafluprost (Tapros®; tafluprost, bimatoprost (Lumigan®; bimatoprost, travoprost (Travatan®; travoprost, travoprost (Travatan Z®; travoprost-Z, benzalkonium chloride (BAK, polyoxyethylene hardening castor oil 40 (HCO-40, and polysorbate 80 (P-80. These experimental solutions were exposed to the cultured cells of a rabbit-derived corneal cell line for a certain time, and the exposure time causing 50% cell damage (CD50, indicated by the ratio of viable cells to total cells was calculated (in vitro. In addition, corneal resistance (CR was measured and CR ratio (post-treatment CR/pretreatment CR × 100 was calculated (in vivo.Results: CD50 of each ophthalmic solution was the longest with tafluprost, followed by travoprost-Z, bimatoprost, travoprost, and latanoprost. CD50 of 0.005%, 0.01%, and 0.02% BAK was 14.5 minutes, 8.1 minutes, and 4.0 minutes, respectively. The number of viable cells decreased to 60%, 8 minutes after exposure with HCO-40, and 30 minutes after being exposed to P-80. The CR ratio was 81.0% with travoprost and 82.0% with latanoprost, indicating a significant posttreatment reduction of CR (P < 0.05. The CR ratio did not decrease after treatment with tafluprost, travoprost-Z, or bimatoprost. The CR ratio of 0.005%, 0.01%, and 0.02% BAK was 105.0%, 90.5%, and 68.7%, respectively, and that of HCO-40 and P-80 was 108.7% and 114.2%, respectively.Conclusion: BAK

Characterising the cellulose synthase complexes of cell walls

NARCIS (Netherlands)

Mansoori Zangir, N.

2012-01-01

One of the characteristics of the plant kingdom is the presence of a structural cell wall. Cellulose is a major component in both the primary and secondary cell walls of plants. In higher plants cellulose is synthesized by so called rosette protein complexes with cellulose synthases (CESAs) as

16 CFR 501.6 - Cellulose sponges, irregular dimensions.

Science.gov (United States)

2010-01-01

... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Cellulose sponges, irregular dimensions. 501... REQUIREMENTS AND PROHIBITIONS UNDER PART 500 § 501.6 Cellulose sponges, irregular dimensions. Variety packages of cellulose sponges of irregular dimensions, are exempted from the requirements of § 500.25 of this...

Optimization of cellulose acrylate and grafted 4-vinylpyridine and 1-vinylimidazole synthesis

Directory of Open Access Journals (Sweden)

Bojanić Vaso

2010-01-01

Full Text Available Optimization of cellulose acrylate synthesis by reaction with sodium cellulosate and acryloyl chloride was carried out. Optimal conditions for conducting the synthesis reaction of cellulose acrylate were as follows: the molar ratio of cellulose/potassium-t-butoxide/acryloyl chloride was 1:3:10 and the optimal reaction time was 10 h. On the basis of elemental analysis with optimal conditions for conducting the reaction of cellulose acrylate, the percentage of substitution of glucose units in cellulose Y = 80.7%, and the degree of substitution of cellulose acrylate DS = 2.4 was determined. The grafting reaction of acrylate vinyl monomers onto cellulose in acetonitrile with initiator azoisobutyronitrile (AIBN in a nitrogen atmosphere was performed, by mixing for 5 h at acetonitrile boiling temperature. Radical copolymerization of synthesized cellulose acrylate and 4-vinylpyridine, 1-vinylimidazole, 1-vinyl-2-pyrrolidinone and 9-vinylcarbazole, cellulose-poly-4-vinylpyridine (Cell-PVP, cellulose-poly-1- vinylimidazole (Cell-PVIm and cellulose-poly-1-vinyl-2-pyrrolidinone (Cell-P1V2P and cellulose-poly-9-vinylcarbazole (Cell-P9VK were synthesized. Acrylate cellulose and cellulose grafted copolymers were confirmed by IR spectroscopy, based on elementary analysis and the characteristics of grafted copolymers of cellulose were determined. The mass share of grafted copolymers, X, the relationship of derivative parts/cellulose vinyl group, Z, and the degree of grafting copolymers of cellulose (mass% were determined. In reaction of methyl iodide and cellulose-poly-4-vinylpyridine (Cell-PVP the cellulose-1-methyl-poly-4-vinylpyridine iodide (Cell-1-Me-PVPJ was synthesized. Cellulose acrylate and grafted copolymers were obtained with better thermal, electrochemical and ion-emulation properties for bonding of noble metals Au, Pt, Pd from water solutions. The synthesis optimization of cellulose acrylate was applied as a model for the synthesis of grafted

Potassium fulvate as co-interpenetrating agent during graft polymerization of acrylic acid from cellulose.

Science.gov (United States)

Ghazy, Mohamed B M; El-Hai, Farag Abd; Mohamed, Magdy F; Essawy, Hisham A

2016-10-01

Grafting polymerization of acrylic acid onto cellulose in presence of potassium fulvate (KF) as a co-interpenetrating agent results enhanced water sorption compared to materials prepared similarly in its absence. The insertion of potassium fulvate (KF) did not affect the grafting process and is thought to proceed in parallel to the graft polymerization via intensive polycondensation reactions of its function groups (-COOH and OH) with COOH of the monomer and OH groups of cellulose. The combination of graft copolymerization and polycondensation reactions is assumed to produce interpenetrating network structure. Fourier transform infrared (FTIR) confirmed successful incorporation within the network structure which is an evidence for formation of interpenetrating network. The obtained structures showed homogeneous uniform surface as revealed by scanning electron microscopy (SEM). The obtained superabsorbent possessed high water absorbency 422 and 48.8g/g in distilled water and saline (0.9wt.% NaCl solution), respectively, and enhanced water retention even at elevated temperatures as revealed by thermogravimetric analysis (TGA). This could be explained by the high content of hydrophilic groups. The new superabsorbents proved to be efficient devices for controlled release of fertilizers which expands their use in agricultural applications. Copyright © 2016 Elsevier B.V. All rights reserved.

Biodegradable Cellulose-based Hydrogels: Design and Applications

Science.gov (United States)

Sannino, Alessandro; Demitri, Christian; Madaghiele, Marta

2009-01-01

Hydrogels are macromolecular networks able to absorb and release water solutions in a reversible manner, in response to specific environmental stimuli. Such stimuli-sensitive behaviour makes hydrogels appealing for the design of ‘smart’ devices, applicable in a variety of technological fields. In particular, in cases where either ecological or biocompatibility issues are concerned, the biodegradability of the hydrogel network, together with the control of the degradation rate, may provide additional value to the developed device. This review surveys the design and the applications of cellulose-based hydrogels, which are extensively investigated due to the large availability of cellulose in nature, the intrinsic degradability of cellulose and the smart behaviour displayed by some cellulose derivatives.

Biodegradable Cellulose-based Hydrogels: Design and Applications

Directory of Open Access Journals (Sweden)

Marta Madaghiele

2009-04-01

Full Text Available Hydrogels are macromolecular networks able to absorb and release water solutions in a reversible manner, in response to specific environmental stimuli. Such stimuli-sensitive behaviour makes hydrogels appealing for the design of ‘smart’ devices, applicable in a variety of technological fields. In particular, in cases where either ecological or biocompatibility issues are concerned, the biodegradability of the hydrogel network, together with the control of the degradation rate, may provide additional value to the developed device. This review surveys the design and the applications of cellulose-based hydrogels, which are extensively investigated due to the large availability of cellulose in nature, the intrinsic degradability of cellulose and the smart behaviour displayed by some cellulose derivatives.

Cellulose binding domain fusion proteins

Science.gov (United States)

Shoseyov, Oded; Shpiegl, Itai; Goldstein, Marc A.; Doi, Roy H.

1998-01-01

A cellulose binding domain (CBD) having a high affinity for crystalline cellulose and chitin is disclosed, along with methods for the molecular cloning and recombinant production thereof. Fusion products comprising the CBD and a second protein are likewise described. A wide range of applications are contemplated for both the CBD and the fusion products, including drug delivery, affinity separations, and diagnostic techniques.

Dental glass ionomer cement reinforced by cellulose microfibers and cellulose nanocrystals

International Nuclear Information System (INIS)

Silva, Rafael M.; Pereira, Fabiano V.; Mota, Felipe A.P.; Watanabe, Evandro; Soares, Suelleng M.C.S.; Santos, Maria Helena

2016-01-01

The aim of this work was to evaluate if the addition of cellulose microfibers (CmF) or cellulose nanocrystals (CNC) would improve the mechanical properties of a commercial dental glass ionomer cement (GIC). Different amounts of CmF and CNC were previously prepared and then added to reinforce the GIC matrix while it was being manipulated. Test specimens with various concentrations of CmF or CNC in their total masses were fabricated and submitted to mechanical tests (to evaluate their compressive and diametral tensile strength, modulus, surface microhardness and wear resistance) and characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR). The incorporation of CmF in the GIC matrix did not greatly improve the mechanical properties of GIC. However, the addition of a small amount of CNC in the GIC led to significant improvements in all of the mechanical properties evaluated: compressive strength (increased up to 110% compared with the control group), elastic modulus increased by 161%, diametral tensile strength increased by 53%, and the mass loss decreased from 10.95 to 3.87%. Because the composites presented a considerable increase in mechanical properties, the modification of the conventional GIC with CNC can represent a new and promising dental restorative material. - Highlights: • Cellulose microfibers (CmF) and cellulose nanocrystals (CNC) were prepared. • The CmF and CNC were incorporated in commercial dental glass ionomer cement (GIC). • Small amount of CNC improved significantly all the mechanical properties evaluated. • Modified GIC with CNC can represent a new and promising dental restorative material.

Cellulosic Bionanocomposites: A Review of Preparation, Properties and Applications

Directory of Open Access Journals (Sweden)

Alain Dufresne

2010-12-01

Full Text Available 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 shown that cellulose nanoparticles could be used as fillers to improve mechanical and barrier properties of biocomposites. Their use for industrial packaging is being investigated, with continuous studies to find innovative solutions for efficient and sustainable systems. Processing is more and more important and different systems are detailed in this paper depending on the polymer solubility, i.e., (i hydrosoluble systems, (ii non-hydrosoluble systems, and (iii emulsion systems. This paper intends to give a clear overview of cellulose nanoparticles reinforced composites with more than 150 references by describing their preparation, characterization, properties and applications.

[A case of ophthalmic artery occlusion following injection of hyaluronic acid into the glabellar area].

Science.gov (United States)

Nonomura, Sakiko; Oshitari, Toshiyuki; Miura, Gen; Chiba, Akihiro; Yamamoto, Shuichi

2014-09-01

We report a case of unilateral blindness due to ophthalmic artery occlusion following injection of hyaluronic acid into the glabellar area for facial soft-tissue augmentation. A 20-year old woman underwent injection of hyaluronic acid into the glabellar area at an aesthetic plastic clinic. Immediately after injection, she suffered nausea, pain, paralysis of limbs and visual loss in her right eye. Hyaluronidase was instanly injected into the same place, but these symptoms did not improve. She was transferred to our hospital's emergency department. At the first examination, she had no light perception in the right eye and her right pupil was dilated. The fundus examination revealed right central artery occlusion. No significant findings were detected in her head. Eye ball massage, hyperbaric oxygen therapy, and drip infusion of urokinase were conducted, but no improvement resulted. Fluorescein and indocyanine green angiography showed no filling of the right retinal and choroidal arteries. Electroretinogram was completely disappeared. Magnetic resonance angiography could not reveal the obstruction point of the ophthalmic artery. Ophthalmic artery occlusion was believed to have occured after injection of hyaluronic acid into the glabellar area.

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.

Films based on oxidized starch and cellulose from barley.

Science.gov (United States)

El Halal, Shanise Lisie Mello; Colussi, Rosana; Deon, Vinícius Gonçalves; Pinto, Vânia Zanella; Villanova, Franciene Almeida; Carreño, Neftali Lenin Villarreal; Dias, Alvaro Renato Guerra; Zavareze, Elessandra da Rosa

2015-11-20

Starch and cellulose fibers were isolated from grains and the husk from barley, respectively. Biodegradable films of native starch or oxidized starches and glycerol with different concentrations of cellulose fibers (0%, 10% and 20%) were prepared. The films were characterized by morphological, mechanical, barrier, and thermal properties. Cellulose fibers isolated from the barley husk were obtained with 75% purity and high crystallinity. The morphology of the films of the oxidized starches, regardless of the fiber addition, was more homogeneous as compared to the film of the native starch. The addition of cellulose fibers in the films increased the tensile strength and decreased elongation. The water vapor permeability of the film of oxidized starch with 20% of cellulose fibers was lower than the without fibers. However the films with cellulose fibers had the highest decomposition with the initial temperature and thermal stability. The oxidized starch and cellulose fibers from barley have a good potential for use in packaging. The addition of cellulose fibers in starch films can contribute to the development of films more resistant that can be applied in food systems to maintain its integrity. Copyright © 2015 Elsevier Ltd. All rights reserved.

[Randomized parallel group study of 0.0015% tafluprost ophthalmic solution in patients with primary open-angle glaucoma or ocular hypertension (comparison with 0.005% latanoprost ophthalmic solution)].

Science.gov (United States)

Ge, Jian; Li, Xiaoxin; Sun, Xinghuai; He, Xiangge; Zhang, Hong

2015-02-01

To confirm the non-inferiority of the IOP-lowering effect of the 0.0015% Tafluprost ophthalmic solution to the 0.005% Latanoprost ophthalmic solution in patients with primary open-angle glaucoma or ocular hypertension.Safety was also compared between two groups. This study was conducted from August 2008 to December 2009, at five clinical trial sites in China. Patients of this study population was diagnosed with primary open-angle glaucoma or ocular hypertension in both eyes.Subjects were randomized into 0.0015% Tafluprost group or 0.005% Latanoprost group.Intraocular pressure (IOP) measurement by Goldmann applanation tonometer, slit-lamp microscopy, Gonioscopy, Fundascopy, Visual acuity test, Perimetry, Blood pressure and pulse rate, Subjective symptoms were compered between two groups at Week 0, Week 2 and Week 4.For main effectiveness evaluation index adopt the bad effect evaluation, safety evaluation index by Fisher's exact test probability method. The 246 subjects/246 eyes were randomized (Tafluprost group:122 subjects/122 eyes, Latanoprost group:124 subjects/ 124 eyes). Change in the IOP at 17:00 of Week 2 is (8.8 ± 3.8) mmHg and (8.9 ± 4.4) mmHg (1 mmHg = 0.133 kPa) in Tafluprost group and Latanoprost group. Percent change in the IOP at 17:00 of Week 2 is (33.2 ± 12.8)% and (34.4 ± 14.1)% in Tafluprost group and Latanoprost group. Change in the IOP at 17:00 at the end of treatment is (9.8 ± 4.0) mmHg and (9.2 ± 4.1) mmHg in Tafluprost group and Latanoprost group. Percent change in the IOP at 17:00 at the end of treatment is 37.2% ± 13.4% group and 35.7% ± 13.0% in Tafluprost and Latanoprost group.In addition, distribution of subjects with percentage decrease of IOP > 30% was 72.5% in Tafluprost group higher than 63.8% in Latanoprost group. The major adverse reactions were conjunctival hyperemia, eye irritation, eye pain and foreign body sensation. The incidence of adverse reactions is 31.7% in Tafluprost group and 20.8% in Latanoprost group. The inter

Integrated production of nano-fibrillated cellulose and cellulosic biofuel (ethanol) by enzymatic fractionation of wood fibers

Science.gov (United States)

Junyong Zhu; Ronald Sabo; Xiaolin Luo

2011-01-01

This study demonstrates the feasibility of integrating the production of nano-fibrillated cellulose (NFC), a potentially highly valuable biomaterial, with sugar/biofuel (ethanol) from wood fibers. Commercial cellulase enzymes were used to fractionate the less recalcitrant amorphous cellulose from a bleached Kraft eucalyptus pulp, resulting in a highly crystalline and...

Some Physical Characteristics of Microcrystalline Cellulose ...

African Journals Online (AJOL)

Purpose: The microcrystalline cellulose is an important ingredient in pharmaceutical, food, cosmetic and other industries. This study aimed at evaluating the physical characteristics of microcrystalline cellulose (CP-MCC), obtained from the raw cotton of Cochlospermum planchonii. Methods: CP-MCC was obtained from the ...

Ignition inhibitors for cellulosic materials

International Nuclear Information System (INIS)

Alvares, N.J.

1976-01-01

By exposing samples to various irradiance levels from a calibrated thermal radiation source, the ignition responses of blackened alpha-cellulose and cotton cloth with and without fire-retardant additives were compared. Samples treated with retardant compounds which showed the most promise were then isothermally pyrolyzed in air for comparisons between the pyrolysis rates. Alpha-cellulose samples containing a mixture of boric acid, borax, and ammonium di-hydrogen phosphate could not be ignited by irradiances up to 4.0 cal cm -2 s-1 (16.7 W/cm 2 ). At higher irradiances the specimens ignited, but flaming lasted only until the flammable gases were depleted. Cotton cloth containing a polymeric retardant with the designation THPC + MM was found to be ignition-resistant to all irradiances below 7.0 cal cm -2 s -1 (29.3 W/cm 2 ). Comparison of the pyrolysis rates of the retardant-treated alpha-cellulose and the retardant-treated cotton showed that the retardant mechanism is qualitatively the same. Similar ignition-response measurements were also made with specimens exposed to ionizing radiation. It was observed that gamma radiation results in ignition retardance of cellulose, while irradiation by neutrons does not

Production of Cellulosic Polymers from Agricultural Wastes

Directory of Open Access Journals (Sweden)

A. U. Israel

2008-01-01

Full Text Available 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 (Saccharium officinarum and plantain stem (Musa paradisiaca. They were subjected to soda pulping and hypochlorite bleaching system. Results obtained show that pulp yield from these materials were: 70.00, 39.59, 55.40, 86.00, 84.60, 80.00, 40.84, 81.67, 35.70, 69.11, 4.54, 47.19, 31.70 and 52.44% respectively. The pulps were acetylated with acetic anhydride in ethanoic acid catalyzed by conc. H2SO4 to obtain cellulose derivatives (Cellulose diacetate and triacetate. The cellulose diacetate yields were 41.20, 17.85, 23.13, 20.80, 20.23, 20.00, 39.00, 44.00, 18.80, 20.75, 20.03, 41.20, 44.00, and 39.00% respectively while the results obtained as average of four determinations for cellulose triacetate yields were: 52.00, 51.00, 43.10, 46.60, 49.00, 35.00, 40.60, 54.00, 57.50, 62.52, 35.70. 52.00, 53.00 and 38.70% respectively for all the agricultural wastes utilized. The presence of these cellulose derivatives was confirmed by a solubility test in acetone and chloroform.

Natural cellulose fiber as substrate for supercapacitor.

Science.gov (United States)

Gui, Zhe; Zhu, Hongli; Gillette, Eleanor; Han, Xiaogang; Rubloff, Gary W; Hu, Liangbing; Lee, Sang Bok

2013-07-23

Cellulose fibers with porous structure and electrolyte absorption properties are considered to be a good potential substrate for the deposition of energy material for energy storage devices. Unlike traditional substrates, such as gold or stainless steel, paper prepared from cellulose fibers in this study not only functions as a substrate with large surface area but also acts as an interior electrolyte reservoir, where electrolyte can be absorbed much in the cellulose fibers and is ready to diffuse into an energy storage material. We demonstrated the value of this internal electrolyte reservoir by comparing a series of hierarchical hybrid supercapacitor electrodes based on homemade cellulose paper or polyester textile integrated with carbon nanotubes (CNTs) by simple solution dip and electrodeposited with MnO2. Atomic layer deposition of Al2O3 onto the fiber surface was used to limit electrolyte absorption into the fibers for comparison. Configurations designed with different numbers of ion diffusion pathways were compared to show that cellulose fibers in paper can act as a good interior electrolyte reservoir and provide an effective pathway for ion transport facilitation. Further optimization using an additional CNT coating resulted in an electrode of paper/CNTs/MnO2/CNTs, which has dual ion diffusion and electron transfer pathways and demonstrated superior supercapacitive performance. This paper highlights the merits of the mesoporous cellulose fibers as substrates for supercapacitor electrodes, in which the water-swelling effect of the cellulose fibers can absorb electrolyte, and the mesoporous internal structure of the fibers can provide channels for ions to diffuse to the electrochemical energy storage materials.

Progesterone increases resistance of ophthalmic and central retinal arteries in climacteric women.

Science.gov (United States)

Souza, M A M De; Souza, B M De; Geber, S

2013-04-01

To evaluate the effect of a synthetic progestin on the vascular resistance of the ophthalmic and central retinal arteries in climacteric women, compared to placebo, using transorbital ultrasound with Doppler velocimetry. We performed a prospective, randomized, double-blinded, placebo-controlled study with 216 climacteric women. Subjects were randomly allocated to one of two groups: either the group receiving placebo (one pill/day for 30 days) (n = 108) or the group receiving progestin (5 mg medroxyprogesterone acetate/day for 30 days) (n = 108). Transorbital Doppler velocimetric ultrasound was performed, before and after treatment; we measured the pulsatility index, resistance index and systole/diastole ratio. The mean ages of the participants in the study group and the control group were 54 ± 6.2 years (range 48-59 years) and 55 ± 6.8 years (range 46-60 years), respectively. When we compared the effect of the progestin on the central retinal artery before and after treatment, we observed a significant increase after the treatment in all Doppler indices. The same was observed when we compared the effect of the progestin on the ophthalmic artery. In the group of women receiving placebo, the Doppler indices were similar before and after treatment. Our results demonstrate the existence of a progestogenic vasoconstrictive effect in the ophthalmic and central retinal arteries. As this study provides new data, the observed effect needs further investigations to better elucidate its extent. Moreover, our findings may be particularly useful to others interested in understanding the vascular dynamics of the cerebral vessels and to researchers running clinical trials related to hormone replacement therapy.

Characterization of cellulose nanowhiskers; Caracterizacao do nanowhiskers de celulose

Energy Technology Data Exchange (ETDEWEB)

Nascimento, Nayra R.; Pinheiro, Ivanei F.; Morales, Ana R.; Ravagnani, Sergio P.; Mei, Lucia, E-mail: 25nareis@gmail.com [Universidade Estadual de Campinas (UNICAMP), SP (Brazil)

2015-07-01

Cellulose is the most abundant polymer earth. The cellulose nanowhiskers can be extracted from the cellulose. These have attracted attention for its use in nanostructured materials for various applications, such as nanocomposites, because they have peculiar characteristics, among them, high aspect ratio, biodegradability and excellent mechanical properties. This work aims to characterize cellulose nanowhiskers from microcrystalline cellulose. Therefore, these materials were characterized by X-ray diffraction (XRD) to assess the degree of crystallinity, infrared spectroscopy (FT-IR), transmission electron microscopy (TEM) to the morphology of nanowhiskers and thermal stability was evaluated by Thermogravimetric Analysis (TGA). (author)

Adsorption of TNT, DNAN, NTO, FOX7, and NQ onto cellulose, chitin, and cellulose triacetate. Insights from Density Functional Theory calculations

Science.gov (United States)

Todde, Guido; Jha, Sanjiv K.; Subramanian, Gopinath; Shukla, Manoj K.

2018-02-01

Insensitive munitions (IM) compounds such as DNAN (2,4-dinitroanisole), NTO (3-nitro-1,2,4-triazol-5-one), NQ (nitroguanidine), and FOX7 (1,1-diamino-2,2-dinitroethene) reduce the risk of accidental explosions due to shock and high temperature exposure. These compounds are being used as replacements for sensitive munition compounds such as TNT (2,4,6-trinitromethylbenzene) and RDX (1,3,5-hexahydro-1,3,5-trinitro-1,3,5-triazine). NTO and NQ in IM compounds are more soluble than TNT or RDX, hence they can easily spread in the environment and get dissolved if exposed to precipitation. DNAN solubility is comparable to TNT solubility. Cellulosic biomass, due to its abundance in the environment and its chemical structure, has a high probability of adsorbing these IM compounds, and thus, it is important to investigate the interactions between cellulose and cellulose like biopolymers (e.g. cellulose triacetate and chitin) with IM compounds. Using Density Functional Theory methods, we have studied the adsorption of TNT, DNAN, NTO, NQ, and FOX7 onto cellulose Iα and Iβ, chitin, and cellulose triacetate I (CTA I). Solvent effects on the adsorption were also investigated. Our results show that all contaminants are more strongly adsorbed onto chitin and cellulose Iα than onto CTA I and cellulose Iβ. Dispersion forces were found to be the predominant contribution to the adsorption energies of all contaminants.

Dissolution of cellulose in ionic liquid: A review

Science.gov (United States)

Mohd, N.; Draman, S. F. S.; Salleh, M. S. N.; Yusof, N. B.

2017-02-01

Dissolution of cellulose with ionic liquids (IL) and deep eutectic solvent (DES) lets the comprehensive dissolution of cellulose. Basically, cellulose can be dissolved, in some hydrophilic ionic liquids, such as 1-butyl-3-methylimidazolium chloride (BMIMCl) and 1-allyl-3-methylimidazolium chloride (AMIMCl). Chloride based ionic liquids are suitable solvents for cellulose dissolution. Although the ILs is very useful in fine chemical industry, its application in the pharmaceutical and food industry have been very limited due to issues with toxicity, purity, and high cost. Seeing to these limitations, new green alternative solvent which is DES was used. This green solvents, may be definitely treated as the next-generation reagents for more sustainable industrial development. Thus, this review aims to discuss the dissolution of cellulose either with ionic liquids or DES and its application.

Structure and engineering of celluloses.

Science.gov (United States)

Pérez, Serge; Samain, Daniel

2010-01-01

This chapter collates the developments and conclusions of many of the extensive studies that have been conducted on cellulose, with particular emphasis on the structural and morphological features while not ignoring the most recent results derived from the elucidation of unique biosynthetic pathways. The presentation of structural and morphological data gathered together in this chapter follows the historical development of our knowledge of the different structural levels of cellulose and its various organizational levels. These levels concern features such as chain conformation, chain polarity, chain association, crystal polarity, and microfibril structure and organization. This chapter provides some historical landmarks related to the evolution of concepts in the field of biopolymer science, which parallel the developments of novel methods for characterization of complex macromolecular structures. The elucidation of the different structural levels of organization opens the way to relating structure to function and properties. The chemical and biochemical methods that have been developed to dissolve and further modify cellulose chains are briefly covered. Particular emphasis is given to the facets of topochemistry and topoenzymology where the morphological features play a key role in determining unique physicochemical properties. A final chapter addresses what might be considered tomorrow's goal in amplifying the economic importance of cellulose in the context of sustainable development. Selected examples illustrate the types of result that can be obtained when cellulose fibers are no longer viewed as inert substrates, and when the polyhydroxyl nature of their surfaces, as well as their entire structural complexity, are taken into account. Copyright © 2010 Elsevier Inc. All rights reserved.

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 equivalent...

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.

Chest tube insertion

Science.gov (United States)

Chest drainage tube insertion; Insertion of tube into chest; Tube thoracostomy; Pericardial drain ... Be careful there are no kinks in your tube. The drainage system should always sit upright and be placed ...

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.

Cellulose nanocrystal: electronically conducting polymer nanocomposites for supercapacitors

OpenAIRE

Liew, Soon Yee

2012-01-01

This thesis describes the use of cellulose nanocrystals for the fabrication of porous nanocomposites with electronic conducting polymers for electrochemical supercapacitor applications. The exceptional strength and negatively charged surface functionalities on cellulose nanocrystals are utilised in these nanocomposites. The negatively charged surface functionalities on cellulose nanocrystals allow their simultaneous incorporation into electropolymerised, positively charged conducting polymer ...

Formation of Irreversible H-bonds in Cellulose Materials

Science.gov (United States)

Umesh P. Agarwal; Sally A. Ralph; Rick S. Reiner; Nicole M. Stark

2015-01-01

Understanding of formation of irreversible Hbonds in cellulose is important in a number of fields. For example, fields as diverse as pulp and paper and enzymatic saccharification of cellulose are affected. In the present investigation, the phenomenon of formation of irreversible H-bonds is studied in a variety of celluloses and under two different drying conditions....

Model films of cellulose. I. Method development and initial results

NARCIS (Netherlands)

Gunnars, S.; Wågberg, L.; Cohen Stuart, M.A.

2002-01-01

This report presents a new method for the preparation of thin cellulose films. NMMO (N- methylmorpholine- N-oxide) was used to dissolve cellulose and addition of DMSO (dimethyl sulfoxide) was used to control viscosity of the cellulose solution. A thin layer of the cellulose solution is spin- coated

Applications of bacterial cellulose and its composites in biomedicine.

Science.gov (United States)

Rajwade, J M; Paknikar, K M; Kumbhar, J V

2015-03-01

Bacterial cellulose produced by few but specific microbial genera is an extremely pure natural exopolysaccharide. Besides providing adhesive properties and a competitive advantage to the cellulose over-producer, bacterial cellulose confers UV protection, ensures maintenance of an aerobic environment, retains moisture, protects against heavy metal stress, etc. This unique nanostructured matrix is being widely explored for various medical and nonmedical applications. It can be produced in various shapes and forms because of which it finds varied uses in biomedicine. The attributes of bacterial cellulose such as biocompatibility, haemocompatibility, mechanical strength, microporosity and biodegradability with its unique surface chemistry make it ideally suited for a plethora of biomedical applications. This review highlights these qualities of bacterial cellulose in detail with emphasis on reports that prove its utility in biomedicine. It also gives an in-depth account of various biomedical applications ranging from implants and scaffolds for tissue engineering, carriers for drug delivery, wound-dressing materials, etc. that are reported until date. Besides, perspectives on limitations of commercialisation of bacterial cellulose have been presented. This review is also an update on the variety of low-cost substrates used for production of bacterial cellulose and its nonmedical applications and includes patents and commercial products based on bacterial cellulose.

Single-molecule study of oxidative enzymatic deconstruction of cellulose.

Science.gov (United States)

Eibinger, Manuel; Sattelkow, Jürgen; Ganner, Thomas; Plank, Harald; Nidetzky, Bernd

2017-10-12

LPMO (lytic polysaccharide monooxygenase) represents a unique paradigm of cellulosic biomass degradation by an oxidative mechanism. Understanding the role of LPMO in deconstructing crystalline cellulose is fundamental to the enzyme's biological function and will help to specify the use of LPMO in biorefinery applications. Here we show with real-time atomic force microscopy that C1 and C4 oxidizing types of LPMO from Neurospora crassa (NcLPMO9F, NcLPMO9C) bind to nanocrystalline cellulose with high preference for the very same substrate surfaces that are also used by a processive cellulase (Trichoderma reesei CBH I) to move along during hydrolytic cellulose degradation. The bound LPMOs, however, are immobile during their adsorbed residence time ( ~ 1.0 min for NcLPMO9F) on cellulose. Treatment with LPMO resulted in fibrillation of crystalline cellulose and strongly ( ≥ 2-fold) enhanced the cellulase adsorption. It also increased enzyme turnover on the cellulose surface, thus boosting the hydrolytic conversion.Understanding the role of enzymes in biomass depolymerization is essential for the development of more efficient biorefineries. Here, the authors show by atomic force microscopy the real-time mechanism of cellulose deconstruction by lytic polysaccharide monooxygenases.

Mechanical properties of cellulose nanomaterials studied by contact resonance atomic force microscopy

Science.gov (United States)

Ryan Wagner; Robert J. Moon; Arvind Raman

2016-01-01

Quantification of the mechanical properties of cellulose nanomaterials is key to the development of new cellulose nanomaterial based products. Using contact resonance atomic force microscopy we measured and mapped the transverse elastic modulus of three types of cellulosic nanoparticles: tunicate cellulose nanocrystals, wood cellulose nanocrystals, and wood cellulose...

Experimental study on the liquefaction of cellulose in supercritical ethanol

Science.gov (United States)

Peng, Jinxing; Liu, Xinyuan; Bao, Zhenbo

2018-03-01

Cellulose is the major composition of solid waste for producing biofuel; cellulose liquefaction is helpful for realizing biomass supercritical liquefaction process. This paper is taking supercritical ethanol as the medium, liquefied cellulose with the intermittence installation of high press cauldron. Experiments have studied technical condition and the technology parameter of cellulose liquefaction in supercritical ethanol, and the pyrolysis mechanism was analysed based on the pyrolysis product. Results show that cellulose can be liquefied, can get good effect through appropriate technology condition. Under not catalyst, highest liquefaction rate of cellulose can reach 73.5%. The composition of the pyrolysis product was determined by GC-MS.

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

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.

Laser tissue welding in ophthalmic surgery.

Science.gov (United States)

Rossi, Francesca; Matteini, Paolo; Ratto, Fulvio; Menabuoni, Luca; Lenzetti, Ivo; Pini, Roberto

2008-09-01

Laser welding of ocular tissues is an alternative technique or adjunct to conventional suturing in ophthalmic surgery. It is based on the photothermal interaction of laser light with the main components of the extracellular matrix of connective tissues. The advantages of the welding procedure with respect to standard suturing and stapling are reduced operation times, lesser inflammation, faster healing and increased ability to induce tissue regeneration. The procedure we set up is based on the use of an infrared diode laser in association with the topical application of the chromophore Indocyanine Green. Laser light may be delivered either continuously or in pulses, thus identifying two different techniques that have been applied clinically in various types of transplants of the cornea.

Biofunctional paper via the covalent modification of cellulose.

Science.gov (United States)

Yu, Arthur; Shang, Jing; Cheng, Fang; Paik, Bradford A; Kaplan, Justin M; Andrade, Rodrigo B; Ratner, Daniel M

2012-07-31

Paper-based analytical devices are the subject of growing interest for the development of low-cost point-of-care diagnostics, environmental monitoring technologies, and research tools for limited-resource settings. However, there are limited chemistries available for the conjugation of biomolecules to cellulose for use in biomedical applications. Herein, divinyl sulfone (DVS) chemistry was demonstrated to immobilize small molecules, proteins, and DNA covalently onto the hydroxyl groups of cellulose membranes through nucleophilic addition. Assays on modified cellulose using protein-carbohydrate and protein-glycoprotein interactions as well as oligonucleotide hybridization showed that the membrane's bioactivity was specific, dose-dependent, and stable over a long period of time. The use of an inkjet printer to form patterns of biomolecules on DVS-activated cellulose illustrates the adaptability of the DVS functionalization technique to pattern sophisticated designs, with potential applications in cellulose-based lateral flow devices.

Ophthalmic compensation of visual ametropia based on a programmable diffractive lens

Science.gov (United States)

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

2013-11-01

Pixelated liquid crystal displays have been widely used as spatial light modulators to implement programmable diffractive optical elements (DOEs), 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. In this paper, we explore the application of programmable diffractive lenses displayed on the pixelated screen of a liquid crystal on silicon spatial light modulator (LCoS-SLM) to ophthalmic optics. In particular, we consider the use of programmable diffractive lenses for the visual compensation of some refractive errors (myopia, hyperopia). The theoretical principles of compensation are described and sketched using geometrical optics and paraxial ray tracing. A series of experiments with artificial eye in optical bench are conducted to analyze the compensation accuracy in terms of optical power and to compare the results with those obtained by means of conventional ophthalmic lenses. Practical considerations oriented to feasible applications are provided.

Endovascular Treatment of Persistent Epistaxis due to Pseudoaneurysm Formation of the Ophthalmic Artery Secondary to Nasogastric Tube

Energy Technology Data Exchange (ETDEWEB)

Selcuk, Hakan, E-mail: hakanselcuk73@yahoo.com; Soylu, Nur; Albayram, Sait; Selcuk, Dogan; Ozer, Harun; Kocer, Naci; Islak, Civan [Cerrahpasa Medical School, Istanbul University, Department of Radiology, Division of Neuroradiology (Turkey)

2005-04-15

We present the case of a 60-year-old man with persistent epistaxis for 20 days that had started 2 weeks after removal of a nasogastric tube placed for an abdominal operation. There was no pathologic finding at selective facial and internal maxillary artery injections. An injury to the ethmoidal branches of the ophthalmic arteries or other arterial origins of bleeding was suspected. The internal carotid artery angiography revealed a pseudoaneurysm of an anterior ethmoidal branch of the left ophthalmic artery. The pseudoaneurysm was occluded with NBCA-histoacryl (25%) injection.

Endovascular Treatment of Persistent Epistaxis due to Pseudoaneurysm Formation of the Ophthalmic Artery Secondary to Nasogastric Tube

International Nuclear Information System (INIS)

Selcuk, Hakan; Soylu, Nur; Albayram, Sait; Selcuk, Dogan; Ozer, Harun; Kocer, Naci; Islak, Civan

2005-01-01

We present the case of a 60-year-old man with persistent epistaxis for 20 days that had started 2 weeks after removal of a nasogastric tube placed for an abdominal operation. There was no pathologic finding at selective facial and internal maxillary artery injections. An injury to the ethmoidal branches of the ophthalmic arteries or other arterial origins of bleeding was suspected. The internal carotid artery angiography revealed a pseudoaneurysm of an anterior ethmoidal branch of the left ophthalmic artery. The pseudoaneurysm was occluded with NBCA-histoacryl (25%) injection

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

Science.gov (United States)

2013-11-15

... amendments), as ``preamendments devices.'' FDA classifies these devices after the Agency takes the following.... FDA-2012-N-1238] Medical Devices; Ophthalmic Devices; Classification of the Scleral Plug AGENCY: Food... scleral plugs in order to provide a reasonable assurance of safety and effectiveness of the device. The...

Efficacy and safety of diquafosol ophthalmic solution in patients with dry eye syndrome: a Japanese phase 2 clinical trial.

Science.gov (United States)

Matsumoto, Yukihiro; Ohashi, Yuichi; Watanabe, Hitoshi; Tsubota, Kazuo

2012-10-01

To investigate the dose-dependent efficacy and safety of diquafosol ophthalmic solution for the treatment of dry eye syndrome. Randomized, double-masked, multicenter, parallel-group, placebo-controlled trial. A total of 286 Japanese patients with dry eye who were prescribed topical diquafosol (1%, n = 96; 3%, n = 96) or placebo ophthalmic solution (n = 94). After a washout period of 2 weeks, qualified subjects were randomized to receive a single drop of 1% or 3% diquafosol or placebo ophthalmic solutions 6 times per day for 6 weeks. The primary outcome measure was fluorescein corneal staining score assessment. The secondary outcome measures were Rose Bengal corneal and conjunctival staining scores, tear break-up time (BUT), and subjective symptom assessment. Safety measures were clinical blood and urine examination and recording of adverse events. Fluorescein corneal staining scores significantly improved with both 1% and 3% topical diquafosol compared with placebo at 4 weeks, respectively (P = 0.037, P = 0.002). There was a dose-dependent effect among the groups. Rose Bengal corneal and conjunctival staining scores also improved significantly with both 1% and 3% diquafosol compared with placebo (P = 0.007 and P = 0.004, respectively). Subjective dry eye symptom scores significantly improved with both diquafosol ophthalmic solutions (P ≤ 0.033), although there were no significant differences in BUT compared with placebo. No significant differences between the treatment groups were observed in relation to the occurrence of adverse events. Both 1% and 3% diquafosol ophthalmic solutions are considered effective and safe for the treatment of dry eye syndrome. Copyright © 2012 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Scientific publications in ophthalmic journals from China and other top-ranking countries: a 12-year review of the literature.

Science.gov (United States)

Huang, Wenbin; Wang, Wei; Zhan, Jiao; Zhou, Minwen; Chen, Shida; Zhang, Xiulan

2013-06-26

Eye diseases with increasing mortality are common health problems that affect people of all ages and demographic backgrounds. In this study, we study the publication characteristics in international ophthalmic journals of the US, the UK, Germany, Australia, Japan, and China. Articles published in 53 ophthalmic journals from 2000 to 2011 were retrieved from the PubMed database. We recorded the number of articles published each year, analyzed the publication type, and evaluated the accumulated and average impact factors (IFs), and the distribution of articles in ophthalmic journals in relation to IFs. The characteristics of publication outputs from China and other top-ranking countries were compared. The total number of articles increased significantly during the past 12 years, with an increase of 51.0%. The growth in the annual number of articles from the US, the UK, Australia, and China showed a significantly positive trend. Publications from the US exceeded those from any other country and had the highest IFs, largest number of total citations of articles, and the most articles published in leading ophthalmic journals. During the past 12 years, China contributed 3.5% of the total publications, and the number of Chinese articles showed a more than 6-fold increase (from 99 to 605, R2 =0.947, P<0.001). The numbers of IFs and citations of articles originating in China were mostly lower than for other top-ranking counties. Research on ophthalmic journals has maintained an upward growing trend from 2000 to 2011. Chinese ophthalmology research has developed rapidly, but the gap still exists between China and other top-ranking countries for the advanced level of research.

Experimental insertions

International Nuclear Information System (INIS)

Sandweiss, J.; Kycia, T.F.

1975-01-01

A discussion is given of the eight identical experimental insertions for the planned ISABELLE storage rings. Four sets of quadrupole doublets are used to match the β functions in the insertions to the values in the cells, and the total free space available at the crossing point is 40 meters. An asymmetric beam energy operation is planned, which will be useful in a number of experiments

Immediate Effects of 3% Diquafosol and 0.1% Hyaluronic Acid Ophthalmic Solution on Tear Break-Up Time in Normal Human Eyes.

Science.gov (United States)

Nam, Ki Tae; Ahn, So Min; Eom, Youngsub; Kim, Hyo Myung; Song, Jong Suk

2015-12-01

The purpose of this study was to evaluate the immediate effect of 3% diquafosol ophthalmic solution on tear break-up time (TBUT) in normal human eyes, and to compare it with that of saline and 0.1% hyaluronate ophthalmic solution. Cross sectional comparative study in the first study, 10 healthy volunteers underwent topical application of 2 different ophthalmic solutions in each eye. Saline was randomly applied to one eye and 3% diquafosol ophthalmic solution was added to the fellow eye. TBUT was measured and video recorded before application and at 5, 10, 15, and 20 min after. The TBUT in each eye was compared at each time point with regard to the 2 different ophthalmic solutions. In the second study, another 10 healthy volunteers were included. The same methods were used to compare the immediate effects of 0.1% hyaluronate and 3% diquafosol ophthalmic solution application on TBUT. In the first study, topical instillation of saline did not increase TBUT. However, 3% diquafosol significantly increased TBUT for up to 15 min after application. At every time point, the TBUT increased more significantly from baseline in the diquafosol group than it did in the saline group. In the second study, 0.1% hyaluronate increased TBUT for up to 5 min after application, while 3% diquafosol increased TBUT for up to 15 min. Although the TBUT changes after 5 min were not significantly different between the 2 groups, the TBUT changes at 10, 15, and 20 min were significantly greater in the 3% diquafosol group than they were in the 0.1% hyaluronic acid group (+1.58 ± 0.82 vs. +0.53 ± 1.36 at 10 min, +0.67 ± 0.91 vs. -0.04 ± 1.29 at 15 min, and -0.06 ± 0.96 vs. -0.59 ± 0.90, diquafosol group vs. hyaluronic acid group). One drop of 3% diquafosol increased TBUT for up to 15 min after application. The immediate effect of 3% diquafosol on TBUT was greater than that of saline and even that of 1% hyaluronate ophthalmic solution.

Effect of γ-radiation on the saccharification of cellulose

International Nuclear Information System (INIS)

De la Rosa, A.M.; Banzon, R.B.; Abad, L.V.; Nuguid, Z.F.; Bulos, A.S.

1985-01-01

The effect of gamma radiation on the acid and saccharification of agricultural cellulosic wastes was investigated. Radiation doses of 200 KGy and higher significantly increased the saccharification of rice straw, rice hull and corn husk. The observed radiation effects varied with the cellulosic material. Rice straw exhibited the greatest radiosensitivity while rice hull showed the least susceptibility to gamma radiation. Possible mechanisms for the radiation-induced degradation of cellulose and agricultural cellulosic wastes are discussed. (author)

Structure and transformation of tactoids in cellulose nanocrystal suspensions

Science.gov (United States)

Wang, Pei-Xi; Hamad, Wadood Y.; MacLachlan, Mark J.

2016-05-01

Cellulose nanocrystals obtained from natural sources are of great interest for many applications. In water, cellulose nanocrystals form a liquid crystalline phase whose hierarchical structure is retained in solid films after drying. Although tactoids, one of the most primitive components of liquid crystals, are thought to have a significant role in the evolution of this phase, they have evaded structural study of their internal organization. Here we report the capture of cellulose nanocrystal tactoids in a polymer matrix. This method allows us to visualize, for the first time, the arrangement of cellulose nanocrystals within individual tactoids by electron microscopy. Furthermore, we can follow the structural evolution of the liquid crystalline phase from tactoids to iridescent-layered films. Our insights into the early nucleation events of cellulose nanocrystals give important information about the growth of cholesteric liquid crystalline phases, especially for cellulose nanocrystals, and are crucial for preparing photonics-quality films.

Formulation and process factors influencing product quality and in vitro performance of ophthalmic ointments.

Science.gov (United States)

Xu, Xiaoming; Al-Ghabeish, Manar; Rahman, Ziyaur; Krishnaiah, Yellela S R; Yerlikaya, Firat; Yang, Yang; Manda, Prashanth; Hunt, Robert L; Khan, Mansoor A

2015-09-30

Owing to its unique anatomical and physiological functions, ocular surface presents special challenges for both design and performance evaluation of the ophthalmic ointment drug products formulated with a variety of bases. The current investigation was carried out to understand and identify the appropriate in vitro methods suitable for quality and performance evaluation of ophthalmic ointment, and to study the effect of formulation and process variables on its critical quality attributes (CQA). The evaluated critical formulation variables include API initial size, drug percentage, and mineral oil percentage while the critical process parameters include mixing rate, temperature, time and cooling rate. The investigated quality and performance attributes include drug assay, content uniformity, API particle size in ointment, rheological characteristics, in vitro drug release and in vitro transcorneal drug permeation. Using design of experiments (DoE) as well as a novel principle component analysis approach, five of the quality and performance attributes (API particle size, storage modulus of ointment, high shear viscosity of ointment, in vitro drug release constant and in vitro transcorneal drug permeation rate constant) were found to be highly influenced by the formulation, in particular the strength of API, and to a lesser degree by processing variables. Correlating the ocular physiology with the physicochemical characteristics of acyclovir ophthalmic ointment suggested that in vitro quality metrics could be a valuable predictor of its in vivo performance. Published by Elsevier B.V.

Efeitos hemostático e estrutural da esponja de celulose liofilizada Hemostatic and structural effects of lyophilized cellulose sponge

Directory of Open Access Journals (Sweden)

LUÍS RENATO MELLO

1998-09-01

fagocitose, fato este ainda não relatado na literatura.Hemostatic effects of oxidized cellulose (Surgicel are well known. Based on a possible similar effect of a sponge obtained after lyophilization of biosynthetic cellulose, two different experimental studies were planned. Phase I - Pieces of cellulose sponge were inserted into small provoked cortical wounds of twelve dogs. The time elapsed to obtain bloodstill after cortical damage and application of cellulose was observed in every dog, searching to detect any possible hemostatic effect of the material. The animals were sacrificed after 7, 30 and 90 days. An average time of 1 minute was elapsed until bleeding control was achieved. No clinical adverse effect was noticed. Microscopy showed histiocytic and mild foreign body reaction at 7 days, which diminished at 30 days. Almost no reaction surrounded the implant at 90 days. Lyophilized cellulose has a peculiar eosinophilic appearance, composed by thin irregular filaments which diminished their thickness with the time. At 90 days only sparse irregular cellulose filaments could be detected. Phase II - Small equal sponge fragments were inserted in the liver of twelve rats and observed 7, 30 and 90 days. At autopsy, small peritoneal adhesions were noticed at 30 and 90 days. Microscopy showed intense histioplasmocytic and foreign body reaction in all animals mainly at 7 days. In two animals, refringent intracellular cellulose particles were evident inside giant foreign body cells after 90 days. This fact evidences that cellulose can be reabsorbed by phagocytic phenomena when implanted in mammalians. A comparative group with other hemostatic material and the same method must be done to clarify the issue of hemostatic effects of this membrane.

Application of ophthalmic ultrasonographyin DR

Directory of Open Access Journals (Sweden)

Ya-Ke Li

2018-02-01

Full Text Available AIM: To investigate the value of ultrasonography in diabetic retinopathy(DR. METHODS: Totally 103 cases(103 eyesof type 2 diabetes mellitus were selected from May 2015 to May 2017 in our hospital, there were 32 patients 32 eyes with non diabetic retinopathy(NDR, 40 patients 40 eyes with non proliferative diabetic retinopathy(NPDR, and 31 patients 31 eyes with proliferative diabetic retinopathy(PDR, 40 healthy volunteers(40 eyeswere selected as control group, the maximum systolic blood flow velocity(PSV, end diastolic velocity(EDVand resistance index(RIof the central retinal artery(CRA, posterior ciliary artery(PCAand ophthalmic artery(OAwere detected by color Doppler ultrasound. RESULTS: The difference of PSV, EDV and RI of CRA, PCA and OA in each group was statistically significant(PPPPCONCLUSION: Color Doppler ultrasound monitoring the hemodynamic changes of ocular blood vessels in diabetes can provide evidence for early detection of diabetic retinopathy.

Cellulose multilayer Membranes manufacture with Ionic liquid

KAUST Repository

Livazovic, Sara; Li, Z.; Behzad, Ali Reza; Peinemann, Klaus-Viktor; Nunes, Suzana Pereira

2015-01-01

and ultrafiltration, with thin selective layers of naturally available cellulose has been hampered by the availability of non-aggressive solvents. We propose the manufacture of cellulose membranes based on two approaches: (i) silylation, coating from solutions

Characterization of Aldehyde Crosslinked Kenaf Regenerated Cellulose Film

Directory of Open Access Journals (Sweden)

Hatika Kaco

2015-08-01

Full Text Available Regenerated cellulose film with better mechanical properties was successfully produced by introducing aldehyde crosslinker during the regeneration process. The cellulose source material was derived from kenaf core powder and dissolved in LiOH/urea solvent at −13 °C to form a cellulose solution. The cellulose solution was cast and coagulated in a crosslinker bath at different percentages of glutaraldehyde (GA and glyoxal (GX to form a regenerated cellulose film. According to Fourier transform infrared spectroscopy (FTIR spectra, the hydroxyl group of the cellulose was reduced, reducing the percentage of swelling as the percentage of crosslinker was increased. X-ray diffraction (XRD patterns showed that the crystallinity index of the crosslinked film was decreased. The pore size of the films decreased as the percentage of crosslinker was increased, resulting in decreased film transparency. The pore volume and percentage of swelling in water of the films also increased with decreases in the pore size as the percentage of crosslinker was increased. The tensile strengths of the GA- and GX-crosslinked films increased by 20 and 15% with the addition of 20% of each crosslinker, respectively.

Physical properties of agave cellulose graft polymethyl methacrylate

Energy Technology Data Exchange (ETDEWEB)

Rosli, Noor Afizah; Ahmad, Ishak; Abdullah, Ibrahim; Anuar, Farah Hannan [Polymer Research Centre (PORCE), School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi Selangor (Malaysia)

2013-11-27

The grafting polymerization of methyl methacrylate and Agave cellulose was prepared and their structural analysis and morphology were investigated. The grafting reaction was carried out in an aqueous medium using ceric ammonium nitrate as an initiator. The structural analysis of the graft copolymers was carried out by Fourier transform infrared and X-ray diffraction. The graft copolymers were also characterized by field emission scanning electron microscopy (FESEM). An additional peak at 1732 cm{sup −1} which was attributed to the C=O of ester stretching vibration of poly(methyl methacrylate), appeared in the spectrum of grafted Agave cellulose. A slight decrease of crystallinity index upon grafting was found from 0.74 to 0.68 for cellulose and grafted Agave cellulose, respectively. Another evidence of grafting showed in the FESEM observation, where the surface of the grafted cellulose was found to be roughed than the raw one.

Structural differences of xylans affect their interaction with cellulose

NARCIS (Netherlands)

Kabel, M.A.; Borne, van den H.; Vincken, J.P.; Voragen, A.G.J.; Schols, H.A.

2007-01-01

The affinity of xylan to cellulose is an important aspect of many industrial processes, e.g. production of cellulose, paper making and bio-ethanol production. However, little is known about the adsorption of structurally different xylans to cellulose. Therefore, the adsorption of various xylans to

Direct observation of the effects of cellulose synthesis inhibitors using live cell imaging of Cellulose Synthase (CESA) in Physcomitrella patens.

Science.gov (United States)

Tran, Mai L; McCarthy, Thomas W; Sun, Hao; Wu, Shu-Zon; Norris, Joanna H; Bezanilla, Magdalena; Vidali, Luis; Anderson, Charles T; Roberts, Alison W

2018-01-15

Results from live cell imaging of fluorescently tagged Cellulose Synthase (CESA) proteins in Cellulose Synthesis Complexes (CSCs) have enhanced our understanding of cellulose biosynthesis, including the mechanisms of action of cellulose synthesis inhibitors. However, this method has been applied only in Arabidopsis thaliana and Brachypodium distachyon thus far. Results from freeze fracture electron microscopy of protonemal filaments of the moss Funaria hygrometrica indicate that a cellulose synthesis inhibitor, 2,6-dichlorobenzonitrile (DCB), fragments CSCs and clears them from the plasma membrane. This differs from Arabidopsis, in which DCB causes CSC accumulation in the plasma membrane and a different cellulose synthesis inhibitor, isoxaben, clears CSCs from the plasma membrane. In this study, live cell imaging of the moss Physcomitrella patens indicated that DCB and isoxaben have little effect on protonemal growth rates, and that only DCB causes tip rupture. Live cell imaging of mEGFP-PpCESA5 and mEGFP-PpCESA8 showed that DCB and isoxaben substantially reduced CSC movement, but had no measureable effect on CSC density in the plasma membrane. These results suggest that DCB and isoxaben have similar effects on CSC movement in P. patens and Arabidopsis, but have different effects on CSC intracellular trafficking, cell growth and cell integrity in these divergent plant lineages.

Structure and dynamics of a complex of cellulose with EDA: insights into the action of amines on cellulose

Energy Technology Data Exchange (ETDEWEB)

Sawada, Daisuke [ORNL; Nishiyama, Yoshiharu [Centre de Recherches sur les Macromolecules Vegetales (CERMAV-CNRS); Petridis, Loukas [ORNL; Parthasarathi, R. [Los Alamos National Laboratory (LANL); Gnanakaran, S [Los Alamos National Laboratory (LANL); Forsyth, V. T. [Institut Laue Langevin and Keele University; Wada, Masahisa [University of Tokyo, Japan; Langan, Paul [ORNL

2013-01-01

The neutron structure of a complex of EDA with cellulose has been determined to reveal the location of hydrogen atoms involved in hydrogen bonding. EDA disrupts the hydrogen bonding pattern of naturally occurring cellulose by accepting a strong hydrogen bond from the O6 hydroxymethyl group as the conformation of this group is rotated from tg to gt. The O3-H O5 intrachain hydrogen bond commonly found in cellulose allomorphs is observed to be disordered in the neutron structure, and quantum chemistry and molecular dynamics calculations show that O3 prefers to donate to EDA. The hydrogen bonding arrangement is highly dynamic with bonds continually being formed and broken thus explaining the difficulty in locating all of the hydrogen atoms in the neutron scattering density maps. Comparison with other polysaccharide-amine complexes supports a common underlying mechanism for amine disruption of cellulose.

Hydrolysis of dilute acid-pretreated cellulose under mild hydrothermal conditions.

Science.gov (United States)

Chimentão, R J; Lorente, E; Gispert-Guirado, F; Medina, F; López, F

2014-10-13

The hydrolysis of dilute acid-pretreated cellulose was investigated in a conventional oven and under microwave heating. Two acids--sulfuric and oxalic--were studied. For both hydrothermal conditions (oven and microwave) the resultant total organic carbon (TOC) values obtained by the hydrolysis of the cellulose pretreated with sulfuric acid were higher than those obtained by the hydrolysis of the cellulose pretreated with oxalic acid. However, the dicarboxylic acid exhibited higher hydrolytic efficiency towards glucose. The hydrolysis of cellulose was greatly promoted by microwave heating. The Rietveld method was applied to fit the X-ray patterns of the resultant cellulose after hydrolysis. Oxalic acid preferentially removed the amorphous region of the cellulose and left the crystalline region untouched. On the other hand, sulfuric acid treatment decreased the ordering of the cellulose by partially disrupting its crystalline structure. Copyright © 2014 Elsevier Ltd. All rights reserved.

Integrated analysis of three bacterial conjunctivitis trials of besifloxacin ophthalmic suspension, 0.6%: microbiological eradication outcomes

Directory of Open Access Journals (Sweden)

Morris TW

2011-09-01

Full Text Available Timothy W Morris1, Lynne S Gearinger1, Dale W Usner2, Michael R Paterno2, Heleen H DeCory3, Timothy L Comstock3, Wolfgang Haas11Microbiology and Sterilization Sciences, 2Clinical Affairs, 3Global Pharmaceutical Medical Affairs, Bausch & Lomb, Rochester, NY, USAPurpose: To assess clinical antimicrobial efficacy results obtained with besifloxacin ophthalmic suspension, 0.6%, administered three times a day (TID for 5 days, integrated across three clinical trials of bacterial conjunctivitis and to investigate any microbiological eradication failures.Methods: Clinical microbiological eradication data from three randomized, double-masked, parallel group studies of patients with bacterial conjunctivitis (two vehicle controlled; one active controlled with moxifloxacin ophthalmic solution, 0.5% were integrated. All bacterial samples isolated at baseline above the species-specific threshold value were subjected to antimicrobial susceptibility testing. Samples isolated at subsequent visits were subjected to susceptibility testing and pulsed-field gel electrophoresis (PFGE to investigate the cause of eradication failures and the potential for drug resistance development.Results: Visit 2 (day 4 or 5 and visit 3 (day 8 overall microbiological eradication rates were 92.2% and 88.4% for besifloxacin ophthalmic suspension compared with 61.4% and 72.5% for vehicle and 91.6% and 85.7% for moxifloxacin ophthalmic solution. Visit 2 and visit 3 microbiological eradication rates for Gram-positive and Gram-negative isolates and for individual species were consistent with the overall eradication rates. The majority of observed eradication failures in any treatment group were due to the persistence of the pathogen isolated at baseline. Eradication failures in the besifloxacin treatment group were not associated with lower antimicrobial susceptibility at baseline. PFGE data showed that the majority of bacterial strains in eyes with eradication failures were identical to

The Effects of Montmorillonite and Cellulose Nanocrystals on Physical Properties of Carboxymethyl Cellulose/Polyvinyl Alcohol Blend Films

Directory of Open Access Journals (Sweden)

Leila Abolghasemi Fakhri

2013-01-01

Full Text Available Cellulose nanocrystal  CNC is a type of nanomaterial which is produced by  partial hydrolysis of cellulose and elimination of its amorphous regions. CNC has several advantages such as biodegradability and safety toward human health. In this study, CNC was produced from cotton linters and methods such as transmission electron microscopy and atomic force microscopy were used for confrmation of nanoscale  size production of cellulose crystals. Carboxymethyl cellulose  CMC/polyvinyl alcohol  PVA-nanoclay  MMT and CMC-PVA-CNC flms, containing 3-10% (wt/wt CMC nanofllers, were prepared by casting method and their physical properties were compared in order to approve the use of CNC instead of MMT for its contribution in improving the physical properties of carboxymethyl cellulose-based  flms.  The  X-ray  diffraction  results  indicated  the  formation  of  an exfoliated nanostructure at all nanoparticle concentrations. The results showed that there was no signifcant difference (p < 0.5 between the moisture absorption properties of flms containing the two types of nanofller. The flms containing nanoclay showed higher mechanical strength compared to those containing CNC. The ultimate tensile strengths of the flms containing 10% nanoclay and CNC were higher than the control flm (69.72% and 47.05%, respectively.

Neuro-ophthalmic and clinical characteristics of brain tumours in a tertiary hospital in Ghana

International Nuclear Information System (INIS)

Tagoe, N. N.; Essuman, V. A.; Fordjuor, G.; Akpalu, J.; Bankah, P.; Ndanu, T.

2015-01-01

Anecdotally, increasing number of patients are seen at Korle Bu Teaching Hospital (KBTH) with brain tumour. Neuro-ophthalmic symptoms and signs may help in timely diagnosis and intervention. The objective of this study is to evaluate the neuro-ophthalmic and clinical characteristics of brain tumour in patients presenting at a tertiary hospital in Ghana. The study design involved a prospective case series involving 36 consecutive patients newly diagnosed with brain tumour from November 2010 to October 2011, at the Ophthalmology, Neurosurgery and Endocrine units of KBTH, Ghana. All patients had clinical diagnosis of brain tumour with confirmation by computerized tomography (CT) or magnetic resonance imaging (MRI). Thirteen patients had histological confirmation of diagnosis. The outcome measures of the study include presenting visual acuity, colour vision, visual fields and cranial nerve deficits. Data of 36 patients were analysed. The results of the study showed that ages ranged from 3 to 69 years, mean (SD) 42.56(±16.6 years). Twenty-six (72%) were females. Tumours included pituitary adenoma (20, 55.5%), meningioma (10, 27.8%), choroid plexus tumour (1, 2.8%), medulloblastom (1, 2.8%), craniopharyngioma (1, 2.8%), haemangioblastoma (1, 2.8%), thalamic tumour (1, 2.8%) and haemangioma (1, 2.8%). Histologically confirmed tumours included pituitary adenoma (9, 69.2%), meningioma (3, 23.1%), craniopharyngioma (1, 7.7%). One patient had both a pituitary adenoma and meningioma. Blurred vision (30, 83.3%), headache (28, 77.8%) and photophobia (13, 36.1%) were predominant symptoms. Commonest neuro-ophthalmic signs were impaired colour vision (62 eyes, 88.6%), optic atrophy (26, 74.3%), unilateral or bitemporal hemianopia (15, 41.5%) and relative afferent pupillary defect (12, 34.3%). Seven (19.4%) patients were visually impaired and nine (25%) blind. Thirty-three of 72(45.8%) eyes had monocular blindness. Common neuro-ophthalmic characteristics were blurred vision

Extraction and characterisation of cellulose nanocrystals from pineapple peel

Directory of Open Access Journals (Sweden)

Ana Raquel Madureira

2018-04-01

Full Text Available The potential of pineapple peel as a source of cellulose nanocrystals was evaluated. Peels skin from fresh-cut fruit was used as raw material. These residues were purified to remove pigments, lipids and hemicellulose, and a bleaching process for delignification was carried out for 4-6 h. All resulting products were characterised for their lignin, hemicellulose, cellulose and ash contents using standard techniques. Dry matter at the end was low (ca. 50% compared with the raw material (ca. 90%. The process applied resulted in ca. 20% (m/m of purified cellulose (ca. 80% purity, with ineligible levels of lignin and hemicellulose present, especially when using 6h of bleaching. The purified cellulose was subject to acid hydrolysis for nanocrystal extraction with two testing times, 30 and 60 minutes. These cellulose nanocrystals had small sizes (< 1000 nm, with high variability and negative zeta potential values. The time of extraction did not affect the nanocrystals’ chemical and physical properties. The use of 6 h of bleaching treatment during purification was shown to be more effective than 4 h. Pineapple peel was demonstrated to be a good source of cellulose for the production of cellulose nanocrystals.

Determination of permeability coefficients of ophthalmic drugs through different layers of porcine, rabbit and bovine eyes.

Science.gov (United States)

Loch, Christian; Zakelj, Simon; Kristl, Albin; Nagel, Stefan; Guthoff, Rudolf; Weitschies, Werner; Seidlitz, Anne

2012-08-30

To treat ophthalmic diseases like glaucoma or inflammatory disorders topically applied ophthalmic formulations such as eye drops are usually used. In addition, novel ophthalmic implants releasing drug substances locally into different parts of the eye are available today. In the work presented here, the permeability coefficients of selected drugs (ciprofloxacin hydrochloride, lidocaine hydrochloride, timolol maleate) for ophthalmic tissues were determined using side-by-side diffusion chambers (so-called Ussing chambers). Sclera, conjunctiva, cornea, choroidea-retina-complex and a complex of conjunctiva-sclera-choroidea-retina were excised from fresh porcine, rabbit and bovine eyes. In the porcine eye tissues the highest P(app) values were obtained for conjunctiva with the exception of lidocaine. Therefore, it can be estimated that a certain amount of drug diffuses or is transported through conjunctiva after application. The P(app) values for sclera were also higher than those for cornea and even more, the surface area of sclera which is available for drug absorption is much larger than that of cornea when applying an implant. The obtained permeability coefficients for sclera and conjunctiva indicate that the administration of periocular implants can be an alternative to topically applied formulations. The complexes of the tissues were a significantly (p<0.01) stronger barrier to the investigated substances than the separated tissues. Distinct differences in permeability coefficients between the investigated animal tissues were observed. Overall the highest P(app) values for all mounted tissues were obtained with the rabbit, followed by porcine and bovine eyes. Because of these distinct interspecies differences one must be very careful when selecting the proper animal model for the permeability experiments. Copyright © 2012 Elsevier B.V. All rights reserved.

Nanofibrillated Cellulose (NFC: A High-Value Co-Product that Improves the Economics of Cellulosic Ethanol Production

Directory of Open Access Journals (Sweden)

Qiong Song

2014-02-01

Full Text Available Cellulosic ethanol is a sustainable alternative to petroleum as a transportation fuel, which could be made biologically from agricultural and forestry residues, municipal waste, or herbaceous and woody crops. Instead of putting efforts on steps overcoming the natural resistance of plants to biological breakdown, our study proposes a unique pathway to improve the outcome of the process by co-producing high-value nanofibrillated cellulose (NFC, offering a new economic leverage for cellulosic ethanol to compete with fossil fuels in the near future. In this study, glucose has been produced by commercial enzymes while the residual solids are converted into NFC via sonification. Here, we report the morphology of fibers changed through the process and yield of glucose in the enzymatic hydrolysis step.

Correlation of ophthalmic examination with carrier status in females potentially harboring a severe Norrie disease gene mutation.

Science.gov (United States)

Khan, Arif O; Aldahmesh, Mohammed A; Meyer, Brian

2008-04-01

To correlate ophthalmic findings with carrier status for a severe Norrie disease (ND) gene mutation (C95F). Prospective interventional case series. Six potential carriers and 1 obligate carrier from a family harboring the mutation. An ophthalmologist blind to the pedigree performed a full ophthalmic examination for the 7 asymptomatic family members. A peripheral blood sample was collected from each for ND gene sequencing. Ophthalmic examination findings (with attention to the presence or absence of retinal findings) and results of ND gene sequencing. Three carriers were identified by molecular genetics, and all 3 of them had peripheral retinal abnormality. However, 3 of the 4 genetically identified noncarriers also exhibited peripheral retinal abnormality. Two of these noncarriers with retinal findings were the offspring of a confirmed noncarrier. The genetically identified noncarrier with a normal peripheral retinal examination was the daughter of an obligate carrier. The presence of peripheral retinal changes was not useful for carrier prediction in a family harboring ND. There are likely additional loci responsible for phenotypic expression.

[Biomimetic mineralization of rod-like cellulose nano-whiskers and spectrum analysis].

Science.gov (United States)

Qu, Ping; Wang, Xuan; Cui, Xiao-xia; Zhang, Li-ping

2012-05-01

Cellulose nano-whiskers/nano-hydroxyapatite composite was prepared with biomimetic mineralization using rod-like cellulose nano-whiskers as template. The cellulose nano-whiskers and cellulose nano-whiskers/nano-hydroxyapatite composite were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscope-energy dispersive analysis of X-rays (SEM-EDXA). Variation and distribution of carbon, oxygen, calcium, and phosphorus in the composites were studied. The morphologies and growth mechanism of nano-hydroxyapatite were analyzed. The results showed that nano-hydroxyapatite was formed on the surface of cellulose nano-whiskers; the carbon-oxygen ratio of cellulose nano-whiskers and cellulose nano-whiskers/nano-hydroxyapatite composite was 1.81 and 1.54, respectively; the calcium-phosphorus ratio of the composite was 1.70. The nucleation of nano-hydroxyapatite was around the hydroxyl groups of cellulose nano-whiskers. It is suggested that there is coordination between the hydroxyl groups of cellulose nano-whiskers and calcium ions of nano-hydroxyapatite. The nano-hydroxyapatite can distribute in the matrix of cellulose nano-whiskers. From the atomic force microscope (AFM) images, we can see that the diameter of the spherical nano-hydroxyapatite particles was about 20 nm.

Dynamic rheology behavior of electron beam-irradiated cellulose pulp/NMMO solution

International Nuclear Information System (INIS)

Zhou Ruimin; Deng Bangjun; Hao Xufeng; Zhou Fei; Wu Xinfeng; Chen Yongkang

2008-01-01

The rheological behavior of irradiated cellulose pulp solution by electron beam was investigated. Storage modulus G', loss modulus G'', the dependence of complex viscosity η* and frequency ω of cellulose solutions were measured by DSR-200 Rheometer (Rheometrics co., USA). The molecular weight of irradiated cellulose was measured via the intrinsic viscosity measurement using an Ubbelohde capillary viscometer. The crystalline structure was studied by FTIR Spectroscopy. The results congruously showed that the molecular weight of pulp cellulose decrease and the molecular weight distribution of cellulose become narrow with increase in the irradiation dose. Moreover, the crystalline structure of the cellulose was destroyed, the force of the snarl between the cellulose molecules weakens and the accessibility of pulp spinning is improved. The study supplies some useful data for spinnability of irradiated cellulose and technical data to the filature industry

Methods of pretreating comminuted cellulosic material with carbonate-containing solutions

Energy Technology Data Exchange (ETDEWEB)

Francis, Raymond

2012-11-06

Methods of pretreating comminuted cellulosic material with an acidic solution and then a carbonate-containing solution to produce a pretreated cellulosic material are provided. The pretreated material may then be further treated in a pulping process, for example, a soda-anthraquinone pulping process, to produce a cellulose pulp. The pretreatment solutions may be extracted from the pretreated cellulose material and selectively re-used, for example, with acid or alkali addition, for the pretreatment solutions. The resulting cellulose pulp is characterized by having reduced lignin content and increased yield compared to prior art treatment processes.

[Insights into engineering of cellulosic ethanol].

Science.gov (United States)

Yue, Guojun; Wu, Guoqing; Lin, Xin

2014-06-01

For energy security, air pollution concerns, coupled with the desire to sustain the agricultural sector and revitalize the rural economy, many countries have applied ethanol as oxygenate or fuel to supplement or replace gasoline in transportation sector. Because of abundant feedstock resources and effective reduction of green-house-gas emissions, the cellulosic ethanol has attracted great attention. With a couple of pioneers beginning to produce this biofuel from biomass in commercial quantities around the world, it is necessary to solve engineering problems and complete the economic assessment in 2015-2016, gradually enter the commercialization stage. To avoid "competing for food with humans and competing for land with food", the 1st generation fuel ethanol will gradually transit to the 2nd generation cellulosic ethanol. Based on the overview of cellulosic ethanol industrialization from domestic and abroad in recent years, the main engineering application problems encountered in pretreatment, enzymes and enzymatic hydrolysis, pentose/hexose co-fermentation strains and processes, equipment were discussed from chemical engineering and biotechnology perspective. The development direction of cellulosic ethanol technology in China was addressed.

Cellulose multilayer Membranes manufacture with Ionic liquid

KAUST Repository

Livazovic, Sara

2015-05-09

Membrane processes are considered energy-efficient for water desalination and treatment. However most membranes are based on polymers prepared from fossil petrochemical sources. The development of multilayer membranes for nanofiltration and ultrafiltration, with thin selective layers of naturally available cellulose has been hampered by the availability of non-aggressive solvents. We propose the manufacture of cellulose membranes based on two approaches: (i) silylation, coating from solutions in tetrahydrofuran, followed by solvent evaporation and cellulose regeneration by acid treatment; (ii) casting from solution in 1-ethyl-3-methylimidazolum acetate ([C2mim]OAc), an ionic liquid, followed by phase inversion in water. By these methods porous supports could be easily coated with semi-crystalline cellulose. The membranes were hydrophilic with contact angles as low as 22.0°, molecular weight cut-off as low as 3000 g mol-1 with corresponding water permeance of 13.8 Lm−2 h−1 bar−1. Self-standing cellulose membranes were also manufactured without porous substrate, using only ionic liquid as green solvent. This membrane was insoluble in water, tetrahydrofuran, hexane, N,N-dimethylformamide, 1-methyl-2-pyrrolidinone and N,N-dimethylacetamide.

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

Efficacy and safety of fixed-combination bimatoprost/timolol ophthalmic solution

OpenAIRE

Moon, Suk Bae; Han, Sang Beom

2017-01-01

Suk Bae Moon,1 Sang Beom Han21Department of Surgery, Kangwon National University Hospital, Kangwon National University Graduate School of Medicine, Chuncheon, Korea, 2Department of Ophthalmology, Kangwon National University Hospital, Kangwon National University Graduate School of Medicine, Chuncheon, KoreaWe read, with interest, the article by Sun et al1 entitled “Patient satisfaction with fixed-combination bimatoprost/timolol ophthalmic solution: a survey study in patients with gla...

Enzymic hydrolysis of cellulosic wastes to glucose

Energy Technology Data Exchange (ETDEWEB)

Spano, L A; Medeiros, J; Mandels, M

1976-01-01

An enzymic process for the conversion of cellulose to glucose is based on the use of a specific enzyme derived from mutant strains of the fungus trichoderma viride which is capable of reacting with the crystalline fraction of the cellulose molecule. The production and mode of action of the cellulase complex produced during the growth of trichoderma viride is discussed as well as the application of such enzymes for the conversion of cellulosic wastes to crude glucose syrup for use in production of chemical feedstocks, single-cell proteins, fuels, solvents, etc.

Degradation of cellulosic substances by Thermomonospora curvata

Energy Technology Data Exchange (ETDEWEB)

Stutzenberger, F J

1979-05-01

Research is reported on the cellulolytic activity of Thermomonospora curvata, a thermophilic cellulolytic actinomycete prevalent in municipal solid waste compost. Various cellulosic wastes were evaluated for their potential for the induction of cellulase synthesis by Th. curvata and the extent of cellulose degradation under optimal culture conditions. All the substrates tested showed significant degradation of their cellulose content with the exception of sawdust and barley straw. In contrast to Trichoderma viride, cotton fibers were the best substrates for both C/sub 1/ and C/sub x/ cellulase production. Further research is recommended. (JSR)

Cellulosic Fibers: Effect of Processing on Fiber Bundle Strength

DEFF Research Database (Denmark)

Thygesen, Anders; Madsen, Bo; Thomsen, Anne Belinda

2011-01-01

A range of differently processed cellulosic fibers from flax and hemp plants were investigated to study the relation between processing of cellulosic fibers and fiber bundle strength. The studied processing methods are applied for yarn production and include retting, scutching, carding, and cotto......A range of differently processed cellulosic fibers from flax and hemp plants were investigated to study the relation between processing of cellulosic fibers and fiber bundle strength. The studied processing methods are applied for yarn production and include retting, scutching, carding...

Cellulose Triacetate Dielectric Films For Capacitors

Science.gov (United States)

Yen, Shiao-Ping S.; Jow, T. Richard

1994-01-01

Cellulose triacetate investigated for use as dielectric material in high-energy-density capacitors for pulsed-electrical-power systems. Films of cellulose triacetate metalized on one or both sides for use as substrates for electrodes and/or as dielectrics between electrodes in capacitors. Used without metalization as simple dielectric films. Advantages include high breakdown strength and self-healing capability.

Large-scale additive manufacturing with bioinspired cellulosic materials.

Science.gov (United States)

Sanandiya, Naresh D; Vijay, Yadunund; Dimopoulou, Marina; Dritsas, Stylianos; Fernandez, Javier G

2018-06-05

Cellulose is the most abundant and broadly distributed organic compound and industrial by-product on Earth. However, despite decades of extensive research, the bottom-up use of cellulose to fabricate 3D objects is still plagued with problems that restrict its practical applications: derivatives with vast polluting effects, use in combination with plastics, lack of scalability and high production cost. Here we demonstrate the general use of cellulose to manufacture large 3D objects. Our approach diverges from the common association of cellulose with green plants and it is inspired by the wall of the fungus-like oomycetes, which is reproduced introducing small amounts of chitin between cellulose fibers. The resulting fungal-like adhesive material(s) (FLAM) are strong, lightweight and inexpensive, and can be molded or processed using woodworking techniques. We believe this first large-scale additive manufacture with ubiquitous biological polymers will be the catalyst for the transition to environmentally benign and circular manufacturing models.

Environmentally friendly cellulose-based polyelectrolytes in wastewater treatment.

Science.gov (United States)

Grenda, Kinga; Arnold, Julien; Gamelas, José A F; Rasteiro, Maria G

2017-09-01

Natural-based polyelectrolytes (PELs), with all the advantages coming from being produced from renewable and biodegradable sources, are a potential solution for the removal of dyes from wastewater. In this work, surplus Eucalyptus bleached cellulose fibres from a paper mill were modified to increase the charge and solubility of cellulose. First, reactive aldehyde groups were introduced in the cellulose backbone by periodate oxidation of cellulose. Further modification with alkylammonium produced positively charged cellulose-based PELs. The final products were characterized by several analytical techniques. The PEL with the highest substitution degree of cationic groups was evaluated for its performance in decolouration processes, bentonite being used as aid. This was found to be effective for colour removal of either anionic or cationic dyes. Bio-PELs can thus be considered as very favourable eco-friendly flocculation agents for decolouration of harsh effluents from several industries, considering their biodegradable nature and thus the ability to produce less sludge.

Regulation of cellulose synthesis in response to stress.

Science.gov (United States)

Kesten, Christopher; Menna, Alexandra; Sánchez-Rodríguez, Clara

2017-12-01

The cell wall is a complex polysaccharide network that provides stability and protection to the plant and is one of the first layers of biotic and abiotic stimuli perception. A controlled remodeling of the primary cell wall is essential for the plant to adapt its growth to environmental stresses. Cellulose, the main component of plant cell walls is synthesized by plasma membrane-localized cellulose synthases moving along cortical microtubule tracks. Recent advancements demonstrate a tight regulation of cellulose synthesis at the primary cell wall by phytohormone networks. Stress-induced perturbations at the cell wall that modify cellulose synthesis and microtubule arrangement activate similar phytohormone-based stress response pathways. The integration of stress perception at the primary cell wall and downstream responses are likely to be tightly regulated by phytohormone signaling pathways in the context of cellulose synthesis and microtubule arrangement. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Grafted Cellulose Based Adsorbents for Selective Separation Purposes

Energy Technology Data Exchange (ETDEWEB)

Takacs, E; Wojnarovits, L [Institute of Isotopes, Hungarian Academy of Sciences, Budapest (Hungary)

2012-09-15

The effect of high energy ionizing radiation on cotton-cellulose was studied. It was found that degradation of cellulose started at low doses, below 5 kGy, resulting in decrease in the degree of polymerization. However, the mechanical properties of cotton-cellulose samples only slightly changed with the dose up to 40 kGy. Acrylate type monomers were successfully grafted to cellulose by mutual and by pre-irradiation grafting technique. With both techniques the grafting yield increased with increasing dose and monomer concentration. In the case of pre-irradiation grafting the increase in grafting time also resulted in an increase in grafting percentage. Cotton-cellulose was functionalized using pre-irradiation grafting (PIG) and simultaneous grafting (SG) of glycidyl methacrylate (GMA). The adsorption properties of this material were further enhanced by {beta}-cyclodextrin (CD) immobilization. This molecule is known for its unique ability to form inclusion complexes among others with aromatic compounds like phenols, pesticide, dyes, etc. (author)

Nanotechnology : emerging applications of cellulose-based green magnetic nanocomposites

Science.gov (United States)

Tao Wang; Zhiyong Cai; Lei Liu; Ilker S. Bayer; Abhijit Biswas

2010-01-01

In recent years, a new type of nanocomposite – cellulose based hybrid nanocomposites, which adopts cellulose nanofibers as matrices, has been intensively developed. Among these materials, hybrid nanocomposites consisting of cellulosic fibers and magnetic nanoparticles have recently attracted much attention due to their potential novel applications in biomedicine,...

A comparative study of green composites based on tapioca starch and celluloses

Science.gov (United States)

Owi, Wei Tieng; Lin, Ong Hui; Sam, Sung Ting; Mern, Chin Kwok; Villagracia, Al Rey; Santos, Gil Nonato C.; Akil, Hazizan Md

2017-07-01

The objective of this study was to compare the properties of green composites based on tapioca starch (TS) and celluloses isolated from empty fruit bunches (EFB) and commercial celluloses from cotton linter (supplied by Sigma). Empty fruit bunches (EFB) acted as the main source to obtain the cellulose by using a chemical approach whereas the commercial cellulose from Sigma was used as reference. The TS/cellulose composite films were prepared using cellulose in varying proportions as filler into TS matrix by a casting method. The amount of celluloses added into the tapioca starch were 5, 10, 15, 20 and 25 phr (as per dry mass of TS). The celluloses were characterized using Fourier transform infrared (FTTR) spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). While the green composite films were analyzed in terms of thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), SEM and tensile properties. FTTR analysis confirmed the removal of non-cellulosic materials such as hemicelluloses and lignin from raw EFB after the chemical treatment. XRD diffractograms revealed that the crystallinity of celluloses EFB increased from 43.1 % of raw EFB to 52.1 %. SEM images showed the fibrillar structure of cellulose isolated from EFB. The TGA and derivative thermogravimetric (DTG) curves of green composite films showed no significant effect on the thermal stability. Melting temperature of TS/cellulose EFB higher than neat TS while TS/cellulose Sigma lower than neat TS. The green composite films with 15 phr cellulose from EFB filler loading provided the best tensile properties in term of its strength and modulus. However, in term of elongation at break, the percentage elongation decreased with the increased of the amount of filler loading. SEM images of the films demonstrated a good interaction between cellulose filler and TS matrix especially with the addition of 15 phr of cellulose from EFB.

Ophthalmic acid accumulation in an Escherichia coli mutant lacking the conserved pyridoxal 5'-phosphate-binding protein YggS.

Science.gov (United States)

Ito, Tomokazu; Yamauchi, Ayako; Hemmi, Hisashi; Yoshimura, Tohru

2016-12-01

Escherichia coli YggS is a highly conserved pyridoxal 5'-phosphate (PLP)-binding protein whose biochemical function is currently unknown. A previous study with a yggS-deficient E. coli strain (ΔyggS) demonstrated that YggS controls l-Ile- and l-Val-metabolism by modulating 2-ketobutyrate (2-KB), l-2-aminobutyrate (l-2-AB), and/or coenzyme A (CoA) availability in a PLP-dependent fashion. In this study, we found that ΔyggS accumulates an unknown metabolite as judged by amino acid analyses. LC/MS and MS/MS analyses of the compound with propyl chloroformate derivatization, and co-chromatography analysis identified this compound as γ-l-glutamyl-l-2-aminobutyryl-glycine (ophthalmic acid), a glutathione (GSH) analogue in which the l-Cys moiety is replaced by l-2-AB. We also determine the metabolic consequence of the yggS mutation. Absence of YggS initially increases l-2-AB availability, and then causes ophthalmic acid accumulation and CoA limitation in the cell. The expression of a γ-glutamylcysteine synthetase and a glutathione synthetase in a ΔyggS background causes high-level accumulation of ophthalmic acid in the cells (∼1.2 nmol/mg cells) in a minimal synthetic medium. This opens the possibility of a first fermentative production of ophthalmic acid. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

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

Science.gov (United States)

2011-12-29

.... FDA-2011-N-0003] Ophthalmic and Topical Dosage Form New Animal Drugs; Ivermectin Topical Solution... solution of ivermectin. DATES: This rule is effective December 29, 2011. FOR FURTHER INFORMATION CONTACT... ANADA 200-318 for [[Page 81807

Electrospinning cellulose based nanofibers for sensor applications

Science.gov (United States)

Nartker, Steven

2009-12-01

Bacterial pathogens have recently become a serious threat to the food and water supply. A biosensor based on an electrochemical immunoassay has been developed for detecting food borne pathogens, such as Escherichia coli (E. coli) O157:H7. These sensors consist of several materials including, cellulose, cellulose nitrate, polyaniline and glass fibers. The current sensors have not been optimized in terms of microscale architecture and materials. The major problem associated with the current sensors is the limited concentration range of pathogens that provides a linear response on the concentration conductivity chart. Electrospinning is a process that can be used to create a patterned fiber mat design that will increase the linear range and lower the detection limit of these sensors by improving the microscale architecture. Using the electrospinning process to produce novel mats of cellulose nitrate will offer improved surface area, and the cellulose nitrate can be treated to further improve chemical interactions required for sensor activity. The macro and micro architecture of the sensor is critical to the performance of the sensors. Electrospinning technology can be used to create patterned architectures of nanofibers that will enhance sensor performance. To date electrospinning of cellulose nitrate has not been performed and optimization of the electrospinning process will provide novel materials suitable for applications such as filtration and sensing. The goal of this research is to identify and elucidate the primary materials and process factors necessary to produce cellulose nitrate nanofibers using the electrospinning process that will improve the performance of biosensors. Cellulose nitrate is readily dissolved in common organic solvents such as acetone, tetrahydrofuran (THF) and N,N dimethylformamide (DMF). These solvents can be mixed with other latent solvents such as ethanol and other alcohols to provide a solvent system with good electrospinning behavior

The ocular distribution of 14C-labeled bromfenac ophthalmic solution 0.07% in a rabbit model

Directory of Open Access Journals (Sweden)

Baklayan GA

2014-09-01

Full Text Available George A Baklayan, Mauricio Muñoz Bausch + Lomb, Irvine, CA, USA Purpose: To evaluate the ocular distribution of an advanced formulation of bromfenac ophthalmic solution. Two studies were conducted in rabbits: 1 a 12-hour parallel-group study comparing the ocular distribution of 14C-bromfenac ophthalmic solution 0.07%, pH 7.8 with that of 14C-bromfenac ophthalmic solution 0.09%, pH 8.3, and 2 a 24-hour study evaluating the ocular distribution of 14C-bromfenac ophthalmic solution 0.07%, pH 7.8.Methods: In the 12-hour study, rabbits were randomized to receive 50 µL of 14C-bromfenac 0.07%, pH 7.8 or 50 µL 14C-bromfenac 0.09%, pH 8.3 in one eye, whereas, in the 24-hour, study both eyes received 50 µL of 14C-bromfenac 0.07%, pH 7.8. Ocular tissues were collected at 1, 2, 4, 8, 12 (both studies and 24 hours (second study only following drug instillation, and tissue radioactivity was determined using liquid scintillation chromatography. Results: Measureable levels of bromfenac were observed in all ocular tissues, with the exception of vitreous humor, regardless of formulation. In the 12-hour study, high concentrations of 14C-bromfenac were found in the sclera, followed by the iris/ciliary body, aqueous humor, choroid, retina, and lens. There was no significant difference between the bromfenac 0.07%, pH 7.8 and bromfenac 0.09%, pH 8.3 formulations in any 14C-bromfenac tissue levels at any time point, with the exception of in sclera at 2 hours post-instillation (0.451 µg eq/g versus 0.302 µg eq/g, respectively, P<0.001. There was also no significant difference in the total amount of 14C-bromfenac in the tissues evaluated following instillation of the two formulations. In the 24-hour study evaluating bromfenac 0.07%, pH 7.8 only, high concentrations of 14C-bromfenac were found 1 hour post-instillation in the cornea (2.402 µg eq/g and conjunctiva (1.049 µg eq/g, two tissues not evaluated in the 12-hour study. The rank order of 14C

Reaction kinetics of cellulose hydrolysis in subcritical and supercritical water

Science.gov (United States)

Olanrewaju, Kazeem Bode

The uncertainties in the continuous supply of fossil fuels from the crisis-ridden oil-rich region of the world is fast shifting focus on the need to utilize cellulosic biomass and develop more efficient technologies for its conversion to fuels and chemicals. One such technology is the rapid degradation of cellulose in supercritical water without the need for an enzyme or inorganic catalyst such as acid. This project focused on the study of reaction kinetics of cellulose hydrolysis in subcritical and supercritical water. Cellulose reactions at hydrothermal conditions can proceed via the homogeneous route involving dissolution and hydrolysis or the heterogeneous path of surface hydrolysis. The work is divided into three main parts. First, the detailed kinetic analysis of cellulose reactions in micro- and tubular reactors was conducted. Reaction kinetics models were applied, and kinetics parameters at both subcritical and supercritical conditions were evaluated. The second major task was the evaluation of yields of water soluble hydrolysates obtained from the hydrolysis of cellulose and starch in hydrothermal reactors. Lastly, changes in molecular weight distribution due to hydrothermolytic degradation of cellulose were investigated. These changes were also simulated based on different modes of scission, and the pattern generated from simulation was compared with the distribution pattern from experiments. For a better understanding of the reaction kinetics of cellulose in subcritical and supercritical water, a series of reactions was conducted in the microreactor. Hydrolysis of cellulose was performed at subcritical temperatures ranging from 270 to 340 °C (tau = 0.40--0.88 s). For the dissolution of cellulose, the reaction was conducted at supercritical temperatures ranging from 375 to 395 °C (tau = 0.27--0.44 s). The operating pressure for the reactions at both subcritical and supercritical conditions was 5000 psig. The results show that the rate-limiting step in

An ophthalmic solution of a peroxisome proliferator-activated receptor gamma agonist prevents corneal inflammation in a rat alkali burn model.

Science.gov (United States)

Uchiyama, Masaaki; Shimizu, Akira; Masuda, Yukinari; Nagasaka, Shinya; Fukuda, Yuh; Takahashi, Hiroshi

2013-01-01

We clarified the effects of an ophthalmic solution of a peroxisome proliferator-activated receptor gamma (PPARγ) agonist on corneal inflammation and wound healing after alkali burn injury in rats. After alkali exposure, either an ophthalmic solution with 0.1% pioglitazone hydrochloride (the PPARγ group) or vehicle (the vehicle group) was topically applied to the cornea until day 14. Histological, immunohistochemical, and real-time reverse transcription polymerase chain reaction analysis were performed. After alkali injury, PPARγ expression increased, with the infiltration of many inflammatory cells. The infiltration of neutrophils and macrophages started from the corneal limbus within 6 h, and developed in the corneal center by day 7, with associated neovascularization. The accumulation of α-smooth muscle actin-positive myofibroblasts and the deposition of type III collagen were noted on day 14. The histological changes were suppressed significantly by treatment with the ophthalmic solution of the PPARγ agonist. In addition, the number of infiltrating M2 macrophages in the cornea was increased by PPARγ agonist treatment. In real-time reverse transcription polymerase chain reaction analysis, the messenger ribonucleic acid expression levels of interleukin-1β (IL-1β), IL-6, IL-8, monocyte chemoattractant protein-1, tumor necrosis factor-α, transforming growth factor beta 1, and vascular endothelial growth factor-A were decreased in the PPARγ group compared to the vehicle group in the early periods of corneal inflammation. The ophthalmic solution of the PPARγ agonist inhibited inflammation, decreased the fibrotic reaction, and prevented neovascularization in the cornea from the early phase after alkali burn injury. The ophthalmic solution of the PPARγ agonist may provide a new treatment strategy with useful clinical applications for corneal inflammation and wound healing.

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

Directory of Open Access Journals (Sweden)

Xianzhen Ma

2014-01-01

Full Text Available 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 sacrificed. On days 45 and 90 after operation, the levels of reactive oxygen species (ROS, mitochondrial membrane potential (ΔΨm, and apoptosis of LECs were analyzed, respectively. Meanwhile, caspase-3 mRNA and protein levels were also determined. Results. The results indicate that the levels of ROS and apoptosis were elevated for LECs in rabbits after operation, whereas ΔΨm was decreased. Caspase-3 was apparently increased at both mRNA and protein levels. Treatment of TP ophthalmic gel could reduce the generation of ROS, maintain ΔΨm, inhibit the overexpression of caspase-3, and thus decrease the apoptosis of LECs of rabbits after operation. Conclusions. TP ophthalmic gel can efficiently inhibit caspase-3 overexpression, reduce the apoptosis of LECs, and prevent LECs from damage. Our result provides a new approach to prevent the development of complicated cataract after vitrectomy.

Fe3O4 Modification of Microcrystalline Cellulose for Composite Materials

OpenAIRE

Dimitrov, Kiril; Herzog, Michael; Nenkova, Sanchi

2013-01-01

A new synthesis method for producing cellulose ferrite micro- and nano- composites was developed and new material properties were studied. Microcrystalline cellulose was modified with a mixture of Fe+2/Fe+3 to produce surface bonded nanoparticles magnetite (Fe3O4). Optimal conditions were determined. Microsized hematite (Fe2O3) was mixed with microcrystalline cellulose and used as a reference. The magnetite modified microcrystalline cellulose and hematite filled microcrystalline cellulose wer...

Dynamic Self-Assembly Induced Rapid Dissolution of Cellulose at Low Temperatures

International Nuclear Information System (INIS)

Cai, J.; Zhang, L.; Liu, S.; Liu, Y.; Xu, X.; Chen, X.; Chu, B.; Guo, X.; Xu, J.

2008-01-01

Cellulose can be dissolved in precooled (-12 C) 7 wt % NaOH-12 wt % urea aqueous solution within 2 min. This interesting process, to our knowledge, represents the most rapid dissolution of native cellulose. The results from 13C NMR, 15N NMR, 1H NMR, FT-IR, small-angle neutron scattering (SANS), transmission electron microscopy (TEM), and wide-angle X-ray diffraction (WAXD) suggested that NaOH 'hydrates' could be more easily attracted to cellulose chains through the formation of new hydrogen-bonded networks at low temperatures, while the urea hydrates could not be associated directly with cellulose. However, the urea hydrates could possibly be self-assembled at the surface of the NaOH hydrogen-bonded cellulose to form an inclusion complex (IC), leading to the dissolution of cellulose. Scattering experiments, including dynamic and static light scattering, indicated that most cellulose molecules, with limited amounts of aggregation, could exist as extended rigid chains in dilute solution. Further, the cellulose solution was relatively unstable and could be very sensitive to temperature, polymer concentration, and storage time, leading to additional aggregations. TEM images and WAXD provided experimental evidence on the formation of a wormlike cellulose IC being surrounded with urea. Therefore, we propose that the cellulose dissolution at -12 C could arise as a result of a fast dynamic self-assembly process among solvent small molecules (NaOH, urea, and water) and the cellulose macromolecules.

Ultrafiltration and Nanofiltration Multilayer Membranes Based on Cellulose

KAUST Repository

Livazovic, Sara

2016-06-09

Membrane processes are considered energy-efficient for water desalination and treatment. However most membranes are based on polymers prepared from fossil petrochemical sources. The development of multilayer membranes for nanofiltration and ultrafiltration, with thin selective layers of naturally available cellulose, has been hampered by the availability of non-aggressive solvents. We propose the manufacture of cellulose membranes based on two approaches: (i) silylation, coating from solutions in tetrahydrofuran, followed by solvent evaporation and cellulose regeneration by acid treatment; (ii) casting from solution in 1-ethyl-3-methylimidazolum acetate ([C2mim]OAc), an ionic liquid, followed by phase inversion in water. In the search for less harsh, greener membrane manufacture, the combination of cellulose and ionic liquid is of high interest. Due to the abundance of OH groups and hydrophilicity, cellulose-based membranes have high permeability and low fouling tendency. Membrane fouling is one of the biggest challenges in membrane industry and technology. Accumulation and deposition of foulants onto the surface reduce membrane efficiency and requires harsh chemical cleaning, therefore increasing the cost of maintenance and replacement. In this work the resistance of cellulose 5 membranes towards model organic foulants such as Suwanee River Humic Acid (SRHA) and crude oil have been investigated. Cellulose membrane was tested in this work for oil-water (o/w) separation and exhibited practically 100 % oil rejection with good flux recovery ratio and membrane resistivity. The influence of anionic, cationic and ionic surfactant as well as pH and crude oil concentration on oil separation was investigated, giving a valuable insight in experimental and operational planning.

Numerical Modeling of Ophthalmic Response to Space

Science.gov (United States)

Nelson, E. S.; Myers, J. G.; Mulugeta, L.; Vera, J.; Raykin, J.; Feola, A.; Gleason, R.; Samuels, B.; Ethier, C. R.

2015-01-01

To investigate ophthalmic changes in spaceflight, we would like to predict the impact of blood dysregulation and elevated intracranial pressure (ICP) on Intraocular Pressure (IOP). Unlike other physiological systems, there are very few lumped parameter models of the eye. The eye model described here is novel in its inclusion of the human choroid and retrobulbar subarachnoid space (rSAS), which are key elements in investigating the impact of increased ICP and ocular blood volume. Some ingenuity was required in modeling the blood and rSAS compartments due to the lack of quantitative data on essential hydrodynamic quantities, such as net choroidal volume and blood flowrate, inlet and exit pressures, and material properties, such as compliances between compartments.

Mechanics of Cellulose Synthase Complexes in Living Plant Cells

Science.gov (United States)

Zehfroosh, Nina; Liu, Derui; Ramos, Kieran P.; Yang, Xiaoli; Goldner, Lori S.; Baskin, Tobias I.

The polymer cellulose is one of the major components of the world's biomass with unique and fascinating characteristics such as its high tensile strength, renewability, biodegradability, and biocompatibility. Because of these distinctive aspects, cellulose has been the subject of enormous scientific and industrial interest, yet there are still fundamental open questions about cellulose biosynthesis. Cellulose is synthesized by a complex of transmembrane proteins called ``Cellulose Synthase A'' (CESA) in the plasma membrane. Studying the dynamics and kinematics of the CESA complex will help reveal the mechanism of cellulose synthesis and permit the development and validation of models of CESA motility. To understand what drives these complexes through the cell membrane, we used total internal reflection fluorescence microscopy (TIRFM) and variable angle epi-fluorescence microscopy to track individual, fluorescently-labeled CESA complexes as they move in the hypocotyl and root of living plants. A mean square displacement analysis will be applied to distinguish ballistic, diffusional, and other forms of motion. We report on the results of these tracking experiments. This work was funded by NSF/PHY-1205989.

Hydration Control of the Mechanical and Dynamical Properties of Cellulose

Energy Technology Data Exchange (ETDEWEB)

Petridis, Loukas; O’Neill, Hugh M.; Johnsen, Mariah [Ripon College, Ripon, Wisconsin 54971, United States; Fan, Bingxin [Department; Schulz, Roland [Department; Mamontov, Eugene; Maranas, Janna [Department; Langan, Paul [Department; Smith, Jeremy C. [Department

2014-10-13

The mechanical and dynamical properties of cellulose, the most abundant biomolecule on earth, are essential for its function in plant cell walls and advanced biomaterials. Cellulose is almost always found in a hydrated state, and it is therefore important to understand how hydration influences its dynamics and mechanics. Here, the nanosecond-time scale dynamics of cellulose is characterized using dynamic neutron scattering experiments and molecular dynamics (MD) simulation. The experiments reveal that hydrated samples exhibit a higher average mean-square displacement above ~240 K. The MD simulation reveals that the fluctuations of the surface hydroxymethyl atoms determine the experimental temperature and hydration dependence. The increase in the conformational disorder of the surface hydroxymethyl groups with temperature follows the cellulose persistence length, suggesting a coupling between structural and mechanical properties of the biopolymer. In the MD simulation, 20% hydrated cellulose is more rigid than the dry form, due to more closely packed cellulose chains and water molecules bridging cellulose monomers with hydrogen bonds. This finding may have implications for understanding the origin of strength and rigidity of secondary plant cell walls. The detailed characterization obtained here describes how hydration-dependent increased fluctuations and hydroxymethyl disorder at the cellulose surface lead to enhancement of the rigidity of this important biomolecule.

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. Copyright © 2014 Elsevier Inc. All rights reserved.

Chitosan Based Regenerated Cellulose Fibers Functionalized with Plasma and Ultrasound

Directory of Open Access Journals (Sweden)

Urška Vrabič Brodnjak

2018-04-01

Full Text Available The great potential of regenerated cellulose fibers, which offer excellent possibilities as a matrix for the design of bioactive materials, was the lead for our research. We focused on the surface modification of fibers to improve the sorption properties of regenerated cellulose and biocomposite regenerated cellulose/chitosan fibers, which are on the market. The purpose of our investigation was also the modification of regenerated cellulose fibers with the functionalization by chitosan as a means of obtaining similar properties to biocomposite regenerated cellulose/chitosan fibers on the market. Argon gas plasma was used for fiber surface activation and chitosan adsorption. Ultrasound was also used as a treatment procedure for the surface activation of regenerated cellulose fibers and treatment with chitosan. Analyses have shown that ultrasonic energy or plasma change the accessibility of free functional groups, structure and reactivity, especially in regenerated cellulose fibers. Changes that occurred in the morphology and in the structure of fibers were also reflected in their physical and chemical properties. Consequently, moisture content, sorption properties and water retention improved.

Insertion device and method for accurate and repeatable target insertion

Science.gov (United States)

Gubeli, III, Joseph F.; Shinn, Michelle D.; Bevins, Michael E.; Dillon-Townes, Lawrence; Neil, George R.

2017-07-04

The present invention discloses a device and a method for inserting and positioning a target within a free electron laser, particle accelerator, or other such device that generates or utilizes a beam of energy or particles. The system includes a three-point registration mechanism that insures angular and translational accuracy and repeatability of positioning upon multiple insertions within the same structure.

Extraction and characterization of cellulose nano whiskers from balsa wood

International Nuclear Information System (INIS)

Morelli, Carolina L.; Bretas, Rosario E.S.; Marconcini, Jose M.; Pereira, Fabiano V.; Branciforti, Marcia C.

2011-01-01

In this study cellulose nano whiskers were obtained from balsa wood. For this purpose, fibers of balsa wood were subjected to hydrolysis reactions for lignin and hemi cellulose digestion and acquisition of nano-scale cellulose. Cellulose nano crystals obtained had medium length and thickness of 176 nm and 7 nm respectively. Infrared spectroscopy and x-ray diffraction showed that the process used for extracting nano whiskers could digest nearly all the lignin and hemi cellulose from the balsa fiber and still preserve the aspect ratio and crystallinity, satisfactory enough for future application in polymer nano composites. Thermogravimetry showed that the onset temperature of thermal degradation of cellulose nano crystals (226 degree C) was higher than the temperature of the balsa fiber (215 degree C), allowing its use in molding processes with many polymers from the molten state.(author)

Characterization of blend hydrogels based on plasticized starch/cellulose acetate/carboxymethyl cellulose synthesized by electron beam irradiation

Science.gov (United States)

Senna, Magdy M.; Mostafa, Abo El-Khair B.; Mahdy, Sanna R.; El-Naggar, Abdel Wahab M.

2016-11-01

Blend hydrogels based on aqueous solutions of plasticized starch and different ratios of cellulose acetate (CA) and carboxymethyl cellulose (CMC) were prepared by electron beam irradiation (EB). The blends before and after EB irradiation were characterized by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The physico-chemical properties of blend hydrogels prepared by electron beam irradiation were improved compared to unirradiated blends.

Multimodal ophthalmic imaging using handheld spectrally encoded coherence tomography and reflectometry (SECTR)

Science.gov (United States)

Leeburg, Kelsey C.; El-Haddad, Mohamed T.; Malone, Joseph D.; Terrones, Benjamin D.; Tao, Yuankai K.

2018-02-01

Scanning laser ophthalmoscopy (SLO) provides high-speed, noninvasive en face imaging of the retinal fundus. Optical coherence tomography (OCT) is the current "gold-standard" for ophthalmic diagnostic imaging and enables depth-resolved visualization of ophthalmic structures and image-based surrogate biomarkers of disease. We present a compact optical and mechanical design for handheld spectrally encoded coherence tomography and reflectometry (SECTR) for multimodality en face spectrally encoded reflectometry (SER) and cross-sectional OCT imaging. We custom-designed a double-pass telecentric scan lens, which halves the size of 4-f optical relays and allowed us to reduce the footprint of our SECTR scan-head by a factor of >2.7x (volume) over our previous design. The double-pass scan lens was optimized for diffraction-limited performance over a +/-10° scan field. SECTR optics and optomechanics were combined in a compact rapid-prototyped enclosure with dimensions 87 x 141.8 x 137 mm (w x h x d). SECTR was implemented using a custom-built 400 kHz 1050 nm swept-source. OCT and SER were simultaneously digitized on dual input channels of a 4 GS/s digitizer at 1.4 GS/s per channel. In vivo human en face SER and cross-sectional OCT images were acquired at 350 fps. OCT volumes of 1000 B-scans were acquired in 2.86 s. We believe clinical translation of our compact handheld design will benefit point-of-care ophthalmic diagnostics in patients who are unable to be imaged on conventional slit-lamp based systems, such as infants and the bedridden. When combined with multi-volumetric registration methods, handheld SECTR will have advantages in motion-artifact free imaging over existing handheld technologies.

The identification of and relief from Fe3+ inhibition for both cellulose and cellulase in cellulose saccharification catalyzed by cellulases from Penicillium decumbens.

Science.gov (United States)

Wang, Mingyu; Mu, Ziming; Wang, Junli; Hou, Shaoli; Han, Lijuan; Dong, Yanmei; Xiao, Lin; Xia, Ruirui; Fang, Xu

2013-04-01

Lignocellulosic biomass is an underutilized, renewable resource that can be converted to biofuels. The key step in this conversion is cellulose saccharification catalyzed by cellulase. In this work, the effect of metal ions on cellulose hydrolysis by cellulases from Penicillium decumbens was reported for the first time. Fe(3+) and Cu(2+) were shown to be inhibitory. Further studies on Fe(3+) inhibition showed the inhibition takes place on both enzyme and substrate levels. Fe(3+) treatment damages cellulases' capability to degrade cellulose and inhibits all major cellulase activities. Fe(3+) treatment also reduces the digestibility of cellulose, due to its oxidation. Treatment of Fe(3+)-treated cellulose with DTT and supplementation of EDTA to saccharification systems partially relieved Fe(3+) inhibition. It was concluded that Fe(3+) inhibition in cellulose degradation is a complicated process in which multiple inhibition events occur, and that relief from Fe(3+) inhibition can be achieved by the supplementation of reducing or chelating agents. Copyright © 2013 Elsevier Ltd. All rights reserved.

Modelling the elastic properties of cellulose nanopaper

DEFF Research Database (Denmark)

Mao, Rui; Goutianos, Stergios; Tu, Wei

2017-01-01

The elastic modulus of cellulose nanopaper was predicted using a two-dimensional (2D) micromechanical fibrous network model. The elastic modulus predicted by the network model was 12 GPa, which is well within the range of experimental data for cellulose nanopapers. The stress state in the network...

Isolation and characterization of microcrystalline cellulose obtained ...

African Journals Online (AJOL)

In this study, microcrystalline cellulose, coded MCC-PNF, was obtained from palm nut (Elaeis guineensis) fibres. MCC-PNF was examined for its physicochemical and powder properties. The powder properties of MCC-PNF were compared to those of the best commercial microcrystalline cellulose grade, Avicel PH 101.

Surface Plasmon Resonance Imaging of the Enzymatic Degradation of Cellulose Microfibrils

Science.gov (United States)

Reiter, Kyle; Raegen, Adam; Clarke, Anthony; Lipkowski, Jacek; Dutcher, John

2012-02-01

As the largest component of biomass on Earth, cellulose represents a significant potential energy reservoir. Enzymatic hydrolysis of cellulose into fermentable sugars, an integral step in the production of biofuel, is a challenging problem on an industrial scale. More efficient conversion processes may be developed by an increased understanding of the action of the cellulolytic enzymes involved in cellulose degradation. We have used our recently developed quantitative, angle-scanning surface plasmon resonance imaging (SPRi) device to study the degradation of cellulose microfibrils upon exposure to cellulosic enzymes. In particular, we have studied the action of individual enzymes, and combinations of enzymes, from the Hypocrea Jecorina cellulase system on heterogeneous, industrially-relevant cellulose substrates. This has allowed us to define a characteristic time of action for the enzymes for different degrees of surface coverage of the cellulose microfibrils.

Cyanobacterial cellulose synthesis in the light of the photanol concept

NARCIS (Netherlands)

Schuurmans, R.M.; Matthijs, H.C.P.; Stal, L.J.; Hellingwerf, K.J.; Sharma, N.K.; Rai, A.K.; Stal, L.J.

2014-01-01

The detailed knowledge already available about cellulose synthases and their regulation, plus emerging insights into the process of cellulose secretion in cyanobacteria make cellulose an attractive polymer for the application of the photanol concept in an economically viable production process. By

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. Copyright © 2014 Elsevier Ltd. All rights reserved.

Radiation and enzyme degradation of cellulose materials

International Nuclear Information System (INIS)

Duchacek, V.

1983-01-01

The results are summed up of a study of the effect of gamma radiation on pure cellulose and on wheat straw. The irradiation of cellulose yields acid substances - formic acid and polyhydroxy acids, toxic malondialdehyde and the most substantial fraction - the saccharides xylose, arabinose, glucose and certain oligosaccharides. A ten-fold reduction of the level of cellulose polymerization can be caused by relatively small doses - (up to 250 kGy). A qualitative analysis was made of the straw before and after irradiation and it was shown that irradiation had no significant effect on the qualitative composition of the straw. A 48 hour enzyme hydrolysis of the cellulose and straw were made after irradiation and an economic evaluation of the process was made. Radiation pretreatment is technically and economically advantageous; the production of fodder using enzyme hydrolysis of irradiated straw is not economically feasible due to the high cost of the enzyme. (M.D.)